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diff --git a/doc/man/scons.1 b/doc/man/scons.1 deleted file mode 100644 index 4bac01b..0000000 --- a/doc/man/scons.1 +++ /dev/null @@ -1,6244 +0,0 @@ -.\" Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011, 2012, 2013 The SCons Foundation -.\" -.\" Permission is hereby granted, free of charge, to any person obtaining -.\" a copy of this software and associated documentation files (the -.\" "Software"), to deal in the Software without restriction, including -.\" without limitation the rights to use, copy, modify, merge, publish, -.\" distribute, sublicense, and/or sell copies of the Software, and to -.\" permit persons to whom the Software is furnished to do so, subject to -.\" the following conditions: -.\" -.\" The above copyright notice and this permission notice shall be included -.\" in all copies or substantial portions of the Software. -.\" -.\" THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY -.\" KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE -.\" WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND -.\" NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE -.\" LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION -.\" OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION -.\" WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. -.\" -.\" doc/man/scons.1 2013/03/03 09:48:35 garyo -.\" -.TH SCONS 1 "March 2013" -.\" ES - Example Start - indents and turns off line fill -.rm ES -.de ES -.RS -.nf -.. -.\" EE - Example End - ends indent and turns line fill back on -.rm EE -.de EE -.fi -.RE -.. -.SH NAME -scons \- a software construction tool -.SH SYNOPSIS -.B scons -[ -.IR options ... -] -[ -.IR name = val ... -] -[ -.IR targets ... -] -.SH DESCRIPTION - -The -.B scons -utility builds software (or other files) by determining which -component pieces must be rebuilt and executing the necessary commands to -rebuild them. - -By default, -.B scons -searches for a file named -.IR SConstruct , -.IR Sconstruct , -or -.I sconstruct -(in that order) in the current directory and reads its -configuration from the first file found. -An alternate file name may be -specified via the -.B -f -option. - -The -.I SConstruct -file can specify subsidiary -configuration files using the -.BR SConscript () -function. -By convention, -these subsidiary files are named -.IR SConscript , -although any name may be used. -(Because of this naming convention, -the term "SConscript files" -is sometimes used to refer -generically to all -.B scons -configuration files, -regardless of actual file name.) - -The configuration files -specify the target files to be built, and -(optionally) the rules to build those targets. Reasonable default -rules exist for building common software components (executable -programs, object files, libraries), so that for most software -projects, only the target and input files need be specified. - -Before reading the -.I SConstruct -file, -.B scons -looks for a directory named -.I site_scons -in various system directories (see below) and the directory containing the -.I SConstruct -file; for each of those dirs which exists, -.I site_scons -is prepended to sys.path, -the file -.IR site_scons/site_init.py , -is evaluated if it exists, -and the directory -.I site_scons/site_tools -is prepended to the default toolpath if it exists. -See the -.I --no-site-dir -and -.I --site-dir -options for more details. - -.B scons -reads and executes the SConscript files as Python scripts, -so you may use normal Python scripting capabilities -(such as flow control, data manipulation, and imported Python libraries) -to handle complicated build situations. -.BR scons , -however, reads and executes all of the SConscript files -.I before -it begins building any targets. -To make this obvious, -.B scons -prints the following messages about what it is doing: - -.ES -$ scons foo.out -scons: Reading SConscript files ... -scons: done reading SConscript files. -scons: Building targets ... -cp foo.in foo.out -scons: done building targets. -$ -.EE - -The status messages -(everything except the line that reads "cp foo.in foo.out") -may be suppressed using the -.B -Q -option. - -.B scons -does not automatically propagate -the external environment used to execute -.B scons -to the commands used to build target files. -This is so that builds will be guaranteed -repeatable regardless of the environment -variables set at the time -.B scons -is invoked. -This also means that if the compiler or other commands -that you want to use to build your target files -are not in standard system locations, -.B scons -will not find them unless -you explicitly set the PATH -to include those locations. -Whenever you create an -.B scons -construction environment, -you can propagate the value of PATH -from your external environment as follows: - -.ES -import os -env = Environment(ENV = {'PATH' : os.environ['PATH']}) -.EE - -Similarly, if the commands use external environment variables -like $PATH, $HOME, $JAVA_HOME, $LANG, $SHELL, $TERM, etc., -these variables can also be explicitly propagated: - -.ES -import os -env = Environment(ENV = {'PATH' : os.environ['PATH'], - 'HOME' : os.environ['HOME']}) -.EE - -Or you may explicitly propagate the invoking user's -complete external environment: - -.ES -import os -env = Environment(ENV = os.environ) -.EE - -This comes at the expense of making your build -dependent on the user's environment being set correctly, -but it may be more convenient for many configurations. - -.B scons -can scan known input files automatically for dependency -information (for example, #include statements -in C or C++ files) and will rebuild dependent files appropriately -whenever any "included" input file changes. -.B scons -supports the -ability to define new scanners for unknown input file types. - -.B scons -knows how to fetch files automatically from -SCCS or RCS subdirectories -using SCCS, RCS or BitKeeper. - -.B scons -is normally executed in a top-level directory containing a -.I SConstruct -file, optionally specifying -as command-line arguments -the target file or files to be built. - -By default, the command - -.ES -scons -.EE - -will build all target files in or below the current directory. -Explicit default targets -(to be built when no targets are specified on the command line) -may be defined the SConscript file(s) -using the -.B Default() -function, described below. - -Even when -.B Default() -targets are specified in the SConscript file(s), -all target files in or below the current directory -may be built by explicitly specifying -the current directory (.) -as a command-line target: - -.ES -scons . -.EE - -Building all target files, -including any files outside of the current directory, -may be specified by supplying a command-line target -of the root directory (on POSIX systems): - -.ES -scons / -.EE - -or the path name(s) of the volume(s) in which all the targets -should be built (on Windows systems): - -.ES -scons C:\\ D:\\ -.EE - -To build only specific targets, -supply them as command-line arguments: - -.ES -scons foo bar -.EE - -in which case only the specified targets will be built -(along with any derived files on which they depend). - -Specifying "cleanup" targets in SConscript files is not usually necessary. -The -.B -c -flag removes all files -necessary to build the specified target: - -.ES -scons -c . -.EE - -to remove all target files, or: - -.ES -scons -c build export -.EE - -to remove target files under build and export. -Additional files or directories to remove can be specified using the -.BR Clean() -function. -Conversely, targets that would normally be removed by the -.B -c -invocation -can be prevented from being removed by using the -.BR NoClean () -function. - -A subset of a hierarchical tree may be built by -remaining at the top-level directory (where the -.I SConstruct -file lives) and specifying the subdirectory as the target to be -built: - -.ES -scons src/subdir -.EE - -or by changing directory and invoking scons with the -.B -u -option, which traverses up the directory -hierarchy until it finds the -.I SConstruct -file, and then builds -targets relatively to the current subdirectory: - -.ES -cd src/subdir -scons -u . -.EE - -.B scons -supports building multiple targets in parallel via a -.B -j -option that takes, as its argument, the number -of simultaneous tasks that may be spawned: - -.ES -scons -j 4 -.EE - -builds four targets in parallel, for example. - -.B scons -can maintain a cache of target (derived) files that can -be shared between multiple builds. When caching is enabled in a -SConscript file, any target files built by -.B scons -will be copied -to the cache. If an up-to-date target file is found in the cache, it -will be retrieved from the cache instead of being rebuilt locally. -Caching behavior may be disabled and controlled in other ways by the -.BR --cache-force , -.BR --cache-disable , -and -.B --cache-show -command-line options. The -.B --random -option is useful to prevent multiple builds -from trying to update the cache simultaneously. - -Values of variables to be passed to the SConscript file(s) -may be specified on the command line: - -.ES -scons debug=1 . -.EE - -These variables are available in SConscript files -through the ARGUMENTS dictionary, -and can be used in the SConscript file(s) to modify -the build in any way: - -.ES -if ARGUMENTS.get('debug', 0): - env = Environment(CCFLAGS = '-g') -else: - env = Environment() -.EE - -The command-line variable arguments are also available -in the ARGLIST list, -indexed by their order on the command line. -This allows you to process them in order rather than by name, -if necessary. -ARGLIST[0] returns a tuple -containing (argname, argvalue). -A Python exception is thrown if you -try to access a list member that -does not exist. - -.B scons -requires Python version 2.4 or later. -There should be no other dependencies or requirements to run -.B scons. - -.\" The following paragraph reflects the default tool search orders -.\" currently in SCons/Tool/__init__.py. If any of those search orders -.\" change, this documentation should change, too. -By default, -.B scons -knows how to search for available programming tools -on various systems. -On Windows systems, -.B scons -searches in order for the -Microsoft Visual C++ tools, -the MinGW tool chain, -the Intel compiler tools, -and the PharLap ETS compiler. -On OS/2 systems, -.B scons -searches in order for the -OS/2 compiler, -the GCC tool chain, -and the Microsoft Visual C++ tools, -On SGI IRIX, IBM AIX, Hewlett Packard HP-UX, and Sun Solaris systems, -.B scons -searches for the native compiler tools -(MIPSpro, Visual Age, aCC, and Forte tools respectively) -and the GCC tool chain. -On all other platforms, -including POSIX (Linux and UNIX) platforms, -.B scons -searches in order -for the GCC tool chain, -the Microsoft Visual C++ tools, -and the Intel compiler tools. -You may, of course, override these default values -by appropriate configuration of -Environment construction variables. - -.SH OPTIONS -In general, -.B scons -supports the same command-line options as GNU -.BR make , -and many of those supported by -.BR cons . - -.TP --b -Ignored for compatibility with non-GNU versions of -.BR make. - -.TP --c, --clean, --remove -Clean up by removing all target files for which a construction -command is specified. -Also remove any files or directories associated to the construction command -using the -.BR Clean () -function. -Will not remove any targets specified by the -.BR NoClean () -function. - -.TP -.RI --cache-debug= file -Print debug information about the -.BR CacheDir () -derived-file caching -to the specified -.IR file . -If -.I file -is -.B \- -(a hyphen), -the debug information are printed to the standard output. -The printed messages describe what signature file names are -being looked for in, retrieved from, or written to the -.BR CacheDir () -directory tree. - -.TP ---cache-disable, --no-cache -Disable the derived-file caching specified by -.BR CacheDir (). -.B scons -will neither retrieve files from the cache -nor copy files to the cache. - -.TP ---cache-force, --cache-populate -When using -.BR CacheDir (), -populate a cache by copying any already-existing, up-to-date -derived files to the cache, -in addition to files built by this invocation. -This is useful to populate a new cache with -all the current derived files, -or to add to the cache any derived files -recently built with caching disabled via the -.B --cache-disable -option. - -.TP ---cache-show -When using -.BR CacheDir () -and retrieving a derived file from the cache, -show the command -that would have been executed to build the file, -instead of the usual report, -"Retrieved `file' from cache." -This will produce consistent output for build logs, -regardless of whether a target -file was rebuilt or retrieved from the cache. - -.TP -.RI --config= mode -This specifies how the -.B Configure -call should use or generate the -results of configuration tests. -The option should be specified from -among the following choices: - -.TP ---config=auto -scons will use its normal dependency mechanisms -to decide if a test must be rebuilt or not. -This saves time by not running the same configuration tests -every time you invoke scons, -but will overlook changes in system header files -or external commands (such as compilers) -if you don't specify those dependecies explicitly. -This is the default behavior. - -.TP ---config=force -If this option is specified, -all configuration tests will be re-run -regardless of whether the -cached results are out of date. -This can be used to explicitly -force the configuration tests to be updated -in response to an otherwise unconfigured change -in a system header file or compiler. - -.TP ---config=cache -If this option is specified, -no configuration tests will be rerun -and all results will be taken from cache. -Note that scons will still consider it an error -if --config=cache is specified -and a necessary test does not -yet have any results in the cache. - -.TP -.RI "-C" " directory" ", --directory=" directory -Change to the specified -.I directory -before searching for the -.IR SConstruct , -.IR Sconstruct , -or -.I sconstruct -file, or doing anything -else. Multiple -.B -C -options are interpreted -relative to the previous one, and the right-most -.B -C -option wins. (This option is nearly -equivalent to -.BR "-f directory/SConstruct" , -except that it will search for -.IR SConstruct , -.IR Sconstruct , -or -.I sconstruct -in the specified directory.) - -.\" .TP -.\" -d -.\" Display dependencies while building target files. Useful for -.\" figuring out why a specific file is being rebuilt, as well as -.\" general debugging of the build process. - -.TP --D -Works exactly the same way as the -.B -u -option except for the way default targets are handled. -When this option is used and no targets are specified on the command line, -all default targets are built, whether or not they are below the current -directory. - -.TP -.RI --debug= type -Debug the build process. -.I type -specifies what type of debugging: - -.TP ---debug=count -Print how many objects are created -of the various classes used internally by SCons -before and after reading the SConscript files -and before and after building targets. -This is not supported when SCons is executed with the Python -.B -O -(optimized) option -or when the SCons modules -have been compiled with optimization -(that is, when executing from -.B *.pyo -files). - -.TP ---debug=duplicate -Print a line for each unlink/relink (or copy) of a variant file from -its source file. Includes debugging info for unlinking stale variant -files, as well as unlinking old targets before building them. - -.TP ---debug=dtree -A synonym for the newer -.B --tree=derived -option. -This will be deprecated in some future release -and ultimately removed. - -.TP ---debug=explain -Print an explanation of precisely why -.B scons -is deciding to (re-)build any targets. -(Note: this does not print anything -for targets that are -.I not -rebuilt.) - -.TP ---debug=findlibs -Instruct the scanner that searches for libraries -to print a message about each potential library -name it is searching for, -and about the actual libraries it finds. - -.TP ---debug=includes -Print the include tree after each top-level target is built. -This is generally used to find out what files are included by the sources -of a given derived file: - -.ES -$ scons --debug=includes foo.o -.EE - -.TP ---debug=memoizer -Prints a summary of hits and misses using the Memoizer, -an internal subsystem that counts -how often SCons uses cached values in memory -instead of recomputing them each time they're needed. - -.TP ---debug=memory -Prints how much memory SCons uses -before and after reading the SConscript files -and before and after building targets. - -.TP ---debug=nomemoizer -A deprecated option preserved for backwards compatibility. - -.TP ---debug=objects -Prints a list of the various objects -of the various classes used internally by SCons. - -.TP ---debug=pdb -Re-run SCons under the control of the -.RI pdb -Python debugger. - -.TP ---debug=prepare -Print a line each time any target (internal or external) -is prepared for building. -.B scons -prints this for each target it considers, even if that -target is up to date (see also --debug=explain). -This can help debug problems with targets that aren't being -built; it shows whether -.B scons -is at least considering them or not. - -.TP ---debug=presub -Print the raw command line used to build each target -before the construction environment variables are substituted. -Also shows which targets are being built by this command. -Output looks something like this: -.ES -$ scons --debug=presub -Building myprog.o with action(s): - $SHCC $SHCFLAGS $SHCCFLAGS $CPPFLAGS $_CPPINCFLAGS -c -o $TARGET $SOURCES -\&... -.EE - -.TP ---debug=stacktrace -Prints an internal Python stack trace -when encountering an otherwise unexplained error. - -.TP ---debug=stree -A synonym for the newer -.B --tree=all,status -option. -This will be deprecated in some future release -and ultimately removed. - -.TP ---debug=time -Prints various time profiling information: -the time spent executing each individual build command; -the total build time (time SCons ran from beginning to end); -the total time spent reading and executing SConscript files; -the total time spent SCons itself spend running -(that is, not counting reading and executing SConscript files); -and both the total time spent executing all build commands -and the elapsed wall-clock time spent executing those build commands. -(When -.B scons -is executed without the -.B -j -option, -the elapsed wall-clock time will typically -be slightly longer than the total time spent -executing all the build commands, -due to the SCons processing that takes place -in between executing each command. -When -.B scons -is executed -.I with -the -.B -j -option, -and your build configuration allows good parallelization, -the elapsed wall-clock time should -be significantly smaller than the -total time spent executing all the build commands, -since multiple build commands and -intervening SCons processing -should take place in parallel.) - -.TP ---debug=tree -A synonym for the newer -.B --tree=all -option. -This will be deprecated in some future release -and ultimately removed. - -.TP -.RI --diskcheck= types -Enable specific checks for -whether or not there is a file on disk -where the SCons configuration expects a directory -(or vice versa), -and whether or not RCS or SCCS sources exist -when searching for source and include files. -The -.I types -argument can be set to: -.BR all , -to enable all checks explicitly -(the default behavior); -.BR none , -to disable all such checks; -.BR match , -to check that files and directories on disk -match SCons' expected configuration; -.BR rcs , -to check for the existence of an RCS source -for any missing source or include files; -.BR sccs , -to check for the existence of an SCCS source -for any missing source or include files. -Multiple checks can be specified separated by commas; -for example, -.B --diskcheck=sccs,rcs -would still check for SCCS and RCS sources, -but disable the check for on-disk matches of files and directories. -Disabling some or all of these checks -can provide a performance boost for large configurations, -or when the configuration will check for files and/or directories -across networked or shared file systems, -at the slight increased risk of an incorrect build -or of not handling errors gracefully -(if include files really should be -found in SCCS or RCS, for example, -or if a file really does exist -where the SCons configuration expects a directory). - -.TP -.RI --duplicate= ORDER -There are three ways to duplicate files in a build tree: hard links, -soft (symbolic) links and copies. The default behaviour of SCons is to -prefer hard links to soft links to copies. You can specify different -behaviours with this option. -.IR ORDER -must be one of -.IR hard-soft-copy -(the default), -.IR soft-hard-copy , -.IR hard-copy , -.IR soft-copy -or -.IR copy . -SCons will attempt to duplicate files using -the mechanisms in the specified order. - -.\" .TP -.\" -e, --environment-overrides -.\" Variables from the execution environment override construction -.\" variables from the SConscript files. - -.TP -.RI -f " file" ", --file=" file ", --makefile=" file ", --sconstruct=" file -Use -.I file -as the initial SConscript file. -Multiple -.B -f -options may be specified, -in which case -.B scons -will read all of the specified files. - -.TP --h, --help -Print a local help message for this build, if one is defined in -the SConscript file(s), plus a line that describes the -.B -H -option for command-line option help. If no local help message -is defined, prints the standard help message about command-line -options. Exits after displaying the appropriate message. - -.TP --H, --help-options -Print the standard help message about command-line options and -exit. - -.TP --i, --ignore-errors -Ignore all errors from commands executed to rebuild files. - -.TP -.RI -I " directory" ", --include-dir=" directory -Specifies a -.I directory -to search for -imported Python modules. If several -.B -I -options -are used, the directories are searched in the order specified. - -.TP ---implicit-cache -Cache implicit dependencies. -This causes -.B scons -to use the implicit (scanned) dependencies -from the last time it was run -instead of scanning the files for implicit dependencies. -This can significantly speed up SCons, -but with the following limitations: -.IP -.B scons -will not detect changes to implicit dependency search paths -(e.g. -.BR CPPPATH ", " LIBPATH ) -that would ordinarily -cause different versions of same-named files to be used. -.IP -.B scons -will miss changes in the implicit dependencies -in cases where a new implicit -dependency is added earlier in the implicit dependency search path -(e.g. -.BR CPPPATH ", " LIBPATH ) -than a current implicit dependency with the same name. - -.TP ---implicit-deps-changed -Forces SCons to ignore the cached implicit dependencies. This causes the -implicit dependencies to be rescanned and recached. This implies -.BR --implicit-cache . - -.TP ---implicit-deps-unchanged -Force SCons to ignore changes in the implicit dependencies. -This causes cached implicit dependencies to always be used. -This implies -.BR --implicit-cache . - -.TP ---interactive -Starts SCons in interactive mode. -The SConscript files are read once and a -.B "scons>>>" -prompt is printed. -Targets may now be rebuilt by typing commands at interactive prompt -without having to re-read the SConscript files -and re-initialize the dependency graph from scratch. - -SCons interactive mode supports the following commands: - -.RS 10 -.TP 6 -.BI build "[OPTIONS] [TARGETS] ..." -Builds the specified -.I TARGETS -(and their dependencies) -with the specified -SCons command-line -.IR OPTIONS . -.B b -and -.B scons -are synonyms. - -The following SCons command-line options affect the -.B build -command: - -.ES ---cache-debug=FILE ---cache-disable, --no-cache ---cache-force, --cache-populate ---cache-show ---debug=TYPE --i, --ignore-errors --j N, --jobs=N --k, --keep-going --n, --no-exec, --just-print, --dry-run, --recon --Q --s, --silent, --quiet ---taskmastertrace=FILE ---tree=OPTIONS -.EE - -.IP "" 6 -Any other SCons command-line options that are specified -do not cause errors -but have no effect on the -.B build -command -(mainly because they affect how the SConscript files are read, -which only happens once at the beginning of interactive mode). - -.TP 6 -.BI clean "[OPTIONS] [TARGETS] ..." -Cleans the specified -.I TARGETS -(and their dependencies) -with the specified options. -.B c -is a synonym. -This command is itself a synonym for -.B "build --clean" - -.TP 6 -.BI exit -Exits SCons interactive mode. -You can also exit by terminating input -(CTRL+D on UNIX or Linux systems, -CTRL+Z on Windows systems). - -.TP 6 -.BI help "[COMMAND]" -Provides a help message about -the commands available in SCons interactive mode. -If -.I COMMAND -is specified, -.B h -and -.B ? -are synonyms. - -.TP 6 -.BI shell "[COMMANDLINE]" -Executes the specified -.I COMMANDLINE -in a subshell. -If no -.I COMMANDLINE -is specified, -executes the interactive command interpreter -specified in the -.B SHELL -environment variable -(on UNIX and Linux systems) -or the -.B COMSPEC -environment variable -(on Windows systems). -.B sh -and -.B ! -are synonyms. - -.TP 6 -.B version -Prints SCons version information. -.RE - -.IP -An empty line repeats the last typed command. -Command-line editing can be used if the -.B readline -module is available. - -.ES -$ scons --interactive -scons: Reading SConscript files ... -scons: done reading SConscript files. -scons>>> build -n prog -scons>>> exit -.EE - -.TP -.RI -j " N" ", --jobs=" N -Specifies the number of jobs (commands) to run simultaneously. -If there is more than one -.B -j -option, the last one is effective. -.\" ??? If the -.\" .B -j -.\" option -.\" is specified without an argument, -.\" .B scons -.\" will not limit the number of -.\" simultaneous jobs. - -.TP --k, --keep-going -Continue as much as possible after an error. The target that -failed and those that depend on it will not be remade, but other -targets specified on the command line will still be processed. - -.\" .TP -.\" .RI -l " N" ", --load-average=" N ", --max-load=" N -.\" No new jobs (commands) will be started if -.\" there are other jobs running and the system load -.\" average is at least -.\" .I N -.\" (a floating-point number). - -.\" -.\" .TP -.\" --list-derived -.\" List derived files (targets, dependencies) that would be built, -.\" but do not build them. -.\" [XXX This can probably go away with the right -.\" combination of other options. Revisit this issue.] -.\" -.\" .TP -.\" --list-actions -.\" List derived files that would be built, with the actions -.\" (commands) that build them. Does not build the files. -.\" [XXX This can probably go away with the right -.\" combination of other options. Revisit this issue.] -.\" -.\" .TP -.\" --list-where -.\" List derived files that would be built, plus where the file is -.\" defined (file name and line number). Does not build the files. -.\" [XXX This can probably go away with the right -.\" combination of other options. Revisit this issue.] - -.TP --m -Ignored for compatibility with non-GNU versions of -.BR make . - -.TP -.RI --max-drift= SECONDS -Set the maximum expected drift in the modification time of files to -.IR SECONDS . -This value determines how long a file must be unmodified -before its cached content signature -will be used instead of -calculating a new content signature (MD5 checksum) -of the file's contents. -The default value is 2 days, which means a file must have a -modification time of at least two days ago in order to have its -cached content signature used. -A negative value means to never cache the content -signature and to ignore the cached value if there already is one. A value -of 0 means to always use the cached signature, -no matter how old the file is. - -.TP -.RI --md5-chunksize= KILOBYTES -Set the block size used to compute MD5 signatures to -.IR KILOBYTES . -This value determines the size of the chunks which are read in at once when -computing MD5 signatures. Files below that size are fully stored in memory -before performing the signature computation while bigger files are read in -block-by-block. A huge block-size leads to high memory consumption while a very -small block-size slows down the build considerably. - -The default value is to use a chunk size of 64 kilobytes, which should -be appropriate for most uses. - -.TP --n, --just-print, --dry-run, --recon -No execute. Print the commands that would be executed to build -any out-of-date target files, but do not execute the commands. - -.TP -.RI --no-site-dir -Prevents the automatic addition of the standard -.I site_scons -dirs to -.IR sys.path . -Also prevents loading the -.I site_scons/site_init.py -modules if they exist, and prevents adding their -.I site_scons/site_tools -dirs to the toolpath. - -.\" .TP -.\" .RI -o " file" ", --old-file=" file ", --assume-old=" file -.\" Do not rebuild -.\" .IR file , -.\" and do -.\" not rebuild anything due to changes in the contents of -.\" .IR file . -.\" .TP -.\" .RI --override " file" -.\" Read values to override specific build environment variables -.\" from the specified -.\" .IR file . -.\" .TP -.\" -p -.\" Print the data base (construction environments, -.\" Builder and Scanner objects) that are defined -.\" after reading the SConscript files. -.\" After printing, a normal build is performed -.\" as usual, as specified by other command-line options. -.\" This also prints version information -.\" printed by the -.\" .B -v -.\" option. -.\" -.\" To print the database without performing a build do: -.\" -.\" .ES -.\" scons -p -q -.\" .EE - -.TP -.RI --profile= file -Run SCons under the Python profiler -and save the results in the specified -.IR file . -The results may be analyzed using the Python -pstats module. - -.TP --q, --question -Do not run any commands, or print anything. Just return an exit -status that is zero if the specified targets are already up to -date, non-zero otherwise. -.TP --Q -Quiets SCons status messages about -reading SConscript files, -building targets -and entering directories. -Commands that are executed -to rebuild target files are still printed. - -.\" .TP -.\" -r, -R, --no-builtin-rules, --no-builtin-variables -.\" Clear the default construction variables. Construction -.\" environments that are created will be completely empty. - -.TP ---random -Build dependencies in a random order. This is useful when -building multiple trees simultaneously with caching enabled, -to prevent multiple builds from simultaneously trying to build -or retrieve the same target files. - -.TP --s, --silent, --quiet -Silent. Do not print commands that are executed to rebuild -target files. -Also suppresses SCons status messages. - -.TP --S, --no-keep-going, --stop -Ignored for compatibility with GNU -.BR make . - -.TP -.RI --site-dir= dir -Uses the named dir as the site dir rather than the default -.I site_scons -dirs. This dir will get prepended to -.IR sys.path , -the module -.IR dir /site_init.py -will get loaded if it exists, and -.IR dir /site_tools -will get added to the default toolpath. - -The default set of -.I site_scons -dirs used when -.I --site-dir -is not specified depends on the system platform, as follows. Note -that the directories are examined in the order given, from most -generic to most specific, so the last-executed site_init.py file is -the most specific one (which gives it the chance to override -everything else), and the dirs are prepended to the paths, again so -the last dir examined comes first in the resulting path. - -.IP "Windows:" -.nf - %ALLUSERSPROFILE/Application Data/scons/site_scons - %USERPROFILE%/Local Settings/Application Data/scons/site_scons - %APPDATA%/scons/site_scons - %HOME%/.scons/site_scons - ./site_scons -.fi -.IP "Mac OS X:" -.nf - /Library/Application Support/SCons/site_scons - /opt/local/share/scons/site_scons (for MacPorts) - /sw/share/scons/site_scons (for Fink) - $HOME/Library/Application Support/SCons/site_scons - $HOME/.scons/site_scons - ./site_scons -.fi -.IP "Solaris:" -.nf - /opt/sfw/scons/site_scons - /usr/share/scons/site_scons - $HOME/.scons/site_scons - ./site_scons -.fi -.IP "Linux, HPUX, and other Posix-like systems:" -.nf - /usr/share/scons/site_scons - $HOME/.scons/site_scons - ./site_scons -.fi - -.TP -.RI --stack-size= KILOBYTES -Set the size stack used to run threads to -.IR KILOBYTES . -This value determines the stack size of the threads used to run jobs. -These are the threads that execute the actions of the builders for the -nodes that are out-of-date. -Note that this option has no effect unless the -.B num_jobs -option, which corresponds to -j and --jobs, is larger than one. Using -a stack size that is too small may cause stack overflow errors. This -usually shows up as segmentation faults that cause scons to abort -before building anything. Using a stack size that is too large will -cause scons to use more memory than required and may slow down the entire -build process. - -The default value is to use a stack size of 256 kilobytes, which should -be appropriate for most uses. You should not need to increase this value -unless you encounter stack overflow errors. - -.TP --t, --touch -Ignored for compatibility with GNU -.BR make . -(Touching a file to make it -appear up-to-date is unnecessary when using -.BR scons .) - -.TP -.RI --taskmastertrace= file -Prints trace information to the specified -.I file -about how the internal Taskmaster object -evaluates and controls the order in which Nodes are built. -A file name of -.B - -may be used to specify the standard output. - -.TP -.RI -tree= options -Prints a tree of the dependencies -after each top-level target is built. -This prints out some or all of the tree, -in various formats, -depending on the -.I options -specified: - -.TP ---tree=all -Print the entire dependency tree -after each top-level target is built. -This prints out the complete dependency tree, -including implicit dependencies and ignored dependencies. - -.TP ---tree=derived -Restricts the tree output to only derived (target) files, -not source files. - -.TP ---tree=status -Prints status information for each displayed node. - -.TP ---tree=prune -Prunes the tree to avoid repeating dependency information -for nodes that have already been displayed. -Any node that has already been displayed -will have its name printed in -.BR "[square brackets]" , -as an indication that the dependencies -for that node can be found by searching -for the relevant output higher up in the tree. - -.IP -Multiple options may be specified, -separated by commas: - -.ES -# Prints only derived files, with status information: -scons --tree=derived,status - -# Prints all dependencies of target, with status information -# and pruning dependencies of already-visited Nodes: -scons --tree=all,prune,status target -.EE - -.TP --u, --up, --search-up -Walks up the directory structure until an -.I SConstruct , -.I Sconstruct -or -.I sconstruct -file is found, and uses that -as the top of the directory tree. -If no targets are specified on the command line, -only targets at or below the -current directory will be built. - -.TP --U -Works exactly the same way as the -.B -u -option except for the way default targets are handled. -When this option is used and no targets are specified on the command line, -all default targets that are defined in the SConscript(s) in the current -directory are built, regardless of what directory the resultant targets end -up in. - -.TP --v, --version -Print the -.B scons -version, copyright information, -list of authors, and any other relevant information. -Then exit. - -.TP --w, --print-directory -Print a message containing the working directory before and -after other processing. - -.TP ---no-print-directory -Turn off -w, even if it was turned on implicitly. - -.TP -.RI --warn= type ", --warn=no-" type -Enable or disable warnings. -.I type -specifies the type of warnings to be enabled or disabled: - -.TP ---warn=all, --warn=no-all -Enables or disables all warnings. - -.TP ---warn=cache-write-error, --warn=no-cache-write-error -Enables or disables warnings about errors trying to -write a copy of a built file to a specified -.BR CacheDir (). -These warnings are disabled by default. - -.TP ---warn=corrupt-sconsign, --warn=no-corrupt-sconsign -Enables or disables warnings about unfamiliar signature data in -.B .sconsign -files. -These warnings are enabled by default. - -.TP ---warn=dependency, --warn=no-dependency -Enables or disables warnings about dependencies. -These warnings are disabled by default. - -.TP ---warn=deprecated, --warn=no-deprecated -Enables or disables all warnings about use of -currently deprecated features. -These warnings are enabled by default. -Note that the -.B --warn=no-deprecated -option does not disable warnings about absolutely all deprecated features. -Warnings for some deprecated features that have already been through -several releases with deprecation warnings -may be mandatory for a release or two -before they are officially no longer supported by SCons. -Warnings for some specific deprecated features -may be enabled or disabled individually; -see below. - -.RS -.TP ---warn=deprecated-copy, --warn=no-deprecated-copy -Enables or disables warnings about use of the deprecated -.B env.Copy() -method. - -.TP ---warn=deprecated-source-signatures, --warn=no-deprecated-source-signatures -Enables or disables warnings about use of the deprecated -.B SourceSignatures() -function or -.B env.SourceSignatures() -method. - -.TP ---warn=deprecated-target-signatures, --warn=no-deprecated-target-signatures -Enables or disables warnings about use of the deprecated -.B TargetSignatures() -function or -.B env.TargetSignatures() -method. -.RE - -.TP ---warn=duplicate-environment, --warn=no-duplicate-environment -Enables or disables warnings about attempts to specify a build -of a target with two different construction environments -that use the same action. -These warnings are enabled by default. - -.TP ---warn=fortran-cxx-mix, --warn=no-fortran-cxx-mix -Enables or disables the specific warning about linking -Fortran and C++ object files in a single executable, -which can yield unpredictable behavior with some compilers. - -.TP ---warn=future-deprecated, --warn=no-future-deprecated -Enables or disables warnings about features -that will be deprecated in the future. -These warnings are disabled by default. -Enabling this warning is especially -recommended for projects that redistribute -SCons configurations for other users to build, -so that the project can be warned as soon as possible -about to-be-deprecated features -that may require changes to the configuration. - -.TP ---warn=link, --warn=no-link -Enables or disables warnings about link steps. - -.TP ---warn=misleading-keywords, --warn=no-misleading-keywords -Enables or disables warnings about use of the misspelled keywords -.B targets -and -.B sources -when calling Builders. -(Note the last -.B s -characters, the correct spellings are -.B target -and -.B source.) -These warnings are enabled by default. - -.TP ---warn=missing-sconscript, --warn=no-missing-sconscript -Enables or disables warnings about missing SConscript files. -These warnings are enabled by default. - -.TP ---warn=no-md5-module, --warn=no-no-md5-module -Enables or disables warnings about the version of Python -not having an MD5 checksum module available. -These warnings are enabled by default. - -.TP ---warn=no-metaclass-support, --warn=no-no-metaclass-support -Enables or disables warnings about the version of Python -not supporting metaclasses when the -.B --debug=memoizer -option is used. -These warnings are enabled by default. - -.TP ---warn=no-object-count, --warn=no-no-object-count -Enables or disables warnings about the -.B --debug=object -feature not working when -.B scons -is run with the python -.B \-O -option or from optimized Python (.pyo) modules. - -.TP ---warn=no-parallel-support, --warn=no-no-parallel-support -Enables or disables warnings about the version of Python -not being able to support parallel builds when the -.B -j -option is used. -These warnings are enabled by default. - -.TP ---warn=python-version, --warn=no-python-version -Enables or disables the warning about running -SCons with a deprecated version of Python. -These warnings are enabled by default. - -.TP ---warn=reserved-variable, --warn=no-reserved-variable -Enables or disables warnings about attempts to set the -reserved construction variable names -.BR CHANGED_SOURCES , -.BR CHANGED_TARGETS , -.BR TARGET , -.BR TARGETS , -.BR SOURCE , -.BR SOURCES , -.BR UNCHANGED_SOURCES -or -.BR UNCHANGED_TARGETS . -These warnings are disabled by default. - -.TP ---warn=stack-size, --warn=no-stack-size -Enables or disables warnings about requests to set the stack size -that could not be honored. -These warnings are enabled by default. - -.\" .TP -.\" .RI --write-filenames= file -.\" Write all filenames considered into -.\" .IR file . -.\" -.\" .TP -.\" .RI -W " file" ", --what-if=" file ", --new-file=" file ", --assume-new=" file -.\" Pretend that the target -.\" .I file -.\" has been -.\" modified. When used with the -.\" .B -n -.\" option, this -.\" show you what would be rebuilt if you were to modify that file. -.\" Without -.\" .B -n -.\" ... what? XXX -.\" -.\" .TP -.\" --warn-undefined-variables -.\" Warn when an undefined variable is referenced. - -.TP -.RI -Y " repository" ", --repository=" repository ", --srcdir=" repository -Search the specified repository for any input and target -files not found in the local directory hierarchy. Multiple -.B -Y -options may be specified, in which case the -repositories are searched in the order specified. - -.SH CONFIGURATION FILE REFERENCE -.\" .SS Python Basics -.\" XXX Adding this in the future would be a help. -.SS Construction Environments -A construction environment is the basic means by which the SConscript -files communicate build information to -.BR scons . -A new construction environment is created using the -.B Environment -function: - -.ES -env = Environment() -.EE - -Variables, called -.I construction -.IR variables , -may be set in a construction environment -either by specifying them as keywords when the object is created -or by assigning them a value after the object is created: - -.ES -env = Environment(FOO = 'foo') -env['BAR'] = 'bar' -.EE - -As a convenience, -construction variables may also be set or modified by the -.I parse_flags -keyword argument, which applies the -.B ParseFlags -method (described below) to the argument value -after all other processing is completed. -This is useful either if the exact content of the flags is unknown -(for example, read from a control file) -or if the flags are distributed to a number of construction variables. - -.ES -env = Environment(parse_flags = '-Iinclude -DEBUG -lm') -.EE - -This example adds 'include' to -.BR CPPPATH , -\&'EBUG' to -.BR CPPDEFINES , -and 'm' to -.BR LIBS . - -By default, a new construction environment is -initialized with a set of builder methods -and construction variables that are appropriate -for the current platform. -An optional platform keyword argument may be -used to specify that an environment should -be initialized for a different platform: - -.ES -env = Environment(platform = 'cygwin') -env = Environment(platform = 'os2') -env = Environment(platform = 'posix') -env = Environment(platform = 'win32') -.EE - -Specifying a platform initializes the appropriate -construction variables in the environment -to use and generate file names with prefixes -and suffixes appropriate for the platform. - -Note that the -.B win32 -platform adds the -.B SystemDrive -and -.B SystemRoot -variables from the user's external environment -to the construction environment's -.B ENV -dictionary. -This is so that any executed commands -that use sockets to connect with other systems -(such as fetching source files from -external CVS repository specifications like -.BR :pserver:anonymous@cvs.sourceforge.net:/cvsroot/scons ) -will work on Windows systems. - -The platform argument may be function or callable object, -in which case the Environment() method -will call the specified argument to update -the new construction environment: - -.ES -def my_platform(env): - env['VAR'] = 'xyzzy' - -env = Environment(platform = my_platform) -.EE - -Additionally, a specific set of tools -with which to initialize the environment -may be specified as an optional keyword argument: - -.ES -env = Environment(tools = ['msvc', 'lex']) -.EE - -Non-built-in tools may be specified using the toolpath argument: - -.ES -env = Environment(tools = ['default', 'foo'], toolpath = ['tools']) -.EE - -This looks for a tool specification in tools/foo.py (as well as -using the ordinary default tools for the platform). foo.py should -have two functions: generate(env, **kw) and exists(env). -The -.B generate() -function -modifies the passed-in environment -to set up variables so that the tool -can be executed; -it may use any keyword arguments -that the user supplies (see below) -to vary its initialization. -The -.B exists() -function should return a true -value if the tool is available. -Tools in the toolpath are used before -any of the built-in ones. For example, adding gcc.py to the toolpath -would override the built-in gcc tool. -Also note that the toolpath is -stored in the environment for use -by later calls to -.BR Clone () -and -.BR Tool () -methods: - -.ES -base = Environment(toolpath=['custom_path']) -derived = base.Clone(tools=['custom_tool']) -derived.CustomBuilder() -.EE - -The elements of the tools list may also -be functions or callable objects, -in which case the Environment() method -will call the specified elements -to update the new construction environment: - -.ES -def my_tool(env): - env['XYZZY'] = 'xyzzy' - -env = Environment(tools = [my_tool]) -.EE - -The individual elements of the tools list -may also themselves be two-element lists of the form -.RI ( toolname ", " kw_dict ). -SCons searches for the -.I toolname -specification file as described above, and -passes -.IR kw_dict , -which must be a dictionary, as keyword arguments to the tool's -.B generate -function. -The -.B generate -function can use the arguments to modify the tool's behavior -by setting up the environment in different ways -or otherwise changing its initialization. - -.ES -# in tools/my_tool.py: -def generate(env, **kw): - # Sets MY_TOOL to the value of keyword argument 'arg1' or 1. - env['MY_TOOL'] = kw.get('arg1', '1') -def exists(env): - return 1 - -# in SConstruct: -env = Environment(tools = ['default', ('my_tool', {'arg1': 'abc'})], - toolpath=['tools']) -.EE - -The tool definition (i.e. my_tool()) can use the PLATFORM variable from -the environment it receives to customize the tool for different platforms. - -If no tool list is specified, then SCons will auto-detect the installed -tools using the PATH variable in the ENV construction variable and the -platform name when the Environment is constructed. Changing the PATH -variable after the Environment is constructed will not cause the tools to -be redetected. - -SCons supports the following tool specifications out of the box: - -.ES -386asm -aixc++ -aixcc -aixf77 -aixlink -ar -as -bcc32 -c++ -cc -cvf -dmd -dvipdf -dvips -f77 -f90 -f95 -fortran -g++ -g77 -gas -gcc -gfortran -gnulink -gs -hpc++ -hpcc -hplink -icc -icl -ifl -ifort -ilink -ilink32 -intelc -jar -javac -javah -latex -lex -link -linkloc -m4 -masm -midl -mingw -mslib -mslink -mssdk -msvc -msvs -mwcc -mwld -nasm -pdflatex -pdftex -qt -rmic -rpcgen -sgiar -sgic++ -sgicc -sgilink -sunar -sunc++ -suncc -sunf77 -sunf90 -sunf95 -sunlink -swig -tar -tex -textfile -tlib -yacc -zip -.EE - -Additionally, there is a "tool" named -.B default -which configures the -environment with a default set of tools for the current platform. - -On posix and cygwin platforms -the GNU tools (e.g. gcc) are preferred by SCons, -on Windows the Microsoft tools (e.g. msvc) -followed by MinGW are preferred by SCons, -and in OS/2 the IBM tools (e.g. icc) are preferred by SCons. - -.SS Builder Methods - -Build rules are specified by calling a construction -environment's builder methods. -The arguments to the builder methods are -.B target -(a list of targets to be built, -usually file names) -and -.B source -(a list of sources to be built, -usually file names). - -Because long lists of file names -can lead to a lot of quoting, -.B scons -supplies a -.B Split() -global function -and a same-named environment method -that split a single string -into a list, separated on -strings of white-space characters. -(These are similar to the split() member function of Python strings -but work even if the input isn't a string.) - -Like all Python arguments, -the target and source arguments to a builder method -can be specified either with or without -the "target" and "source" keywords. -When the keywords are omitted, -the target is first, -followed by the source. -The following are equivalent examples of calling the Program builder method: - -.ES -env.Program('bar', ['bar.c', 'foo.c']) -env.Program('bar', Split('bar.c foo.c')) -env.Program('bar', env.Split('bar.c foo.c')) -env.Program(source = ['bar.c', 'foo.c'], target = 'bar') -env.Program(target = 'bar', Split('bar.c foo.c')) -env.Program(target = 'bar', env.Split('bar.c foo.c')) -env.Program('bar', source = 'bar.c foo.c'.split()) -.EE - -Target and source file names -that are not absolute path names -(that is, do not begin with -.B / -on POSIX systems -or -.B \\ -on Windows systems, -with or without -an optional drive letter) -are interpreted relative to the directory containing the -.B SConscript -file being read. -An initial -.B # -(hash mark) -on a path name means that the rest of the file name -is interpreted relative to -the directory containing -the top-level -.B SConstruct -file, -even if the -.B # -is followed by a directory separator character -(slash or backslash). - -Examples: - -.ES -# The comments describing the targets that will be built -# assume these calls are in a SConscript file in the -# a subdirectory named "subdir". - -# Builds the program "subdir/foo" from "subdir/foo.c": -env.Program('foo', 'foo.c') - -# Builds the program "/tmp/bar" from "subdir/bar.c": -env.Program('/tmp/bar', 'bar.c') - -# An initial '#' or '#/' are equivalent; the following -# calls build the programs "foo" and "bar" (in the -# top-level SConstruct directory) from "subdir/foo.c" and -# "subdir/bar.c", respectively: -env.Program('#foo', 'foo.c') -env.Program('#/bar', 'bar.c') - -# Builds the program "other/foo" (relative to the top-level -# SConstruct directory) from "subdir/foo.c": -env.Program('#other/foo', 'foo.c') -.EE - -When the target shares the same base name -as the source and only the suffix varies, -and if the builder method has a suffix defined for the target file type, -then the target argument may be omitted completely, -and -.B scons -will deduce the target file name from -the source file name. -The following examples all build the -executable program -.B bar -(on POSIX systems) -or -.B bar.exe -(on Windows systems) -from the bar.c source file: - -.ES -env.Program(target = 'bar', source = 'bar.c') -env.Program('bar', source = 'bar.c') -env.Program(source = 'bar.c') -env.Program('bar.c') -.EE - -As a convenience, a -.B srcdir -keyword argument may be specified -when calling a Builder. -When specified, -all source file strings that are not absolute paths -will be interpreted relative to the specified -.BR srcdir . -The following example will build the -.B build/prog -(or -.B build/prog.exe -on Windows) -program from the files -.B src/f1.c -and -.BR src/f2.c : - -.ES -env.Program('build/prog', ['f1.c', 'f2.c'], srcdir='src') -.EE - -It is possible to override or add construction variables when calling a -builder method by passing additional keyword arguments. -These overridden or added -variables will only be in effect when building the target, so they will not -affect other parts of the build. For example, if you want to add additional -libraries for just one program: - -.ES -env.Program('hello', 'hello.c', LIBS=['gl', 'glut']) -.EE - -or generate a shared library with a non-standard suffix: - -.ES -env.SharedLibrary('word', 'word.cpp', - SHLIBSUFFIX='.ocx', - LIBSUFFIXES=['.ocx']) -.EE - -(Note that both the $SHLIBSUFFIX and $LIBSUFFIXES variables must be set -if you want SCons to search automatically -for dependencies on the non-standard library names; -see the descriptions of these variables, below, for more information.) - -It is also possible to use the -.I parse_flags -keyword argument in an override: - -.ES -env = Program('hello', 'hello.c', parse_flags = '-Iinclude -DEBUG -lm') -.EE - -This example adds 'include' to -.BR CPPPATH , -\&'EBUG' to -.BR CPPDEFINES , -and 'm' to -.BR LIBS . - -Although the builder methods defined by -.B scons -are, in fact, -methods of a construction environment object, -they may also be called without an explicit environment: - -.ES -Program('hello', 'hello.c') -SharedLibrary('word', 'word.cpp') -.EE - -In this case, -the methods are called internally using a default construction -environment that consists of the tools and values that -.B scons -has determined are appropriate for the local system. - -Builder methods that can be called without an explicit -environment may be called from custom Python modules that you -import into an SConscript file by adding the following -to the Python module: - -.ES -from SCons.Script import * -.EE - -All builder methods return a list-like object -containing Nodes that -represent the target or targets that will be built. -A -.I Node -is an internal SCons object -which represents -build targets or sources. - -The returned Node-list object -can be passed to other builder methods as source(s) -or passed to any SCons function or method -where a filename would normally be accepted. -For example, if it were necessary -to add a specific -.B -D -flag when compiling one specific object file: - -.ES -bar_obj_list = env.StaticObject('bar.c', CPPDEFINES='-DBAR') -env.Program(source = ['foo.c', bar_obj_list, 'main.c']) -.EE - -Using a Node in this way -makes for a more portable build -by avoiding having to specify -a platform-specific object suffix -when calling the Program() builder method. - -Note that Builder calls will automatically "flatten" -the source and target file lists, -so it's all right to have the bar_obj list -return by the StaticObject() call -in the middle of the source file list. -If you need to manipulate a list of lists returned by Builders -directly using Python, -you can either build the list by hand: - -.ES -foo = Object('foo.c') -bar = Object('bar.c') -objects = ['begin.o'] + foo + ['middle.o'] + bar + ['end.o'] -for object in objects: - print str(object) -.EE - -Or you can use the -.BR Flatten () -function supplied by scons -to create a list containing just the Nodes, -which may be more convenient: - -.ES -foo = Object('foo.c') -bar = Object('bar.c') -objects = Flatten(['begin.o', foo, 'middle.o', bar, 'end.o']) -for object in objects: - print str(object) -.EE - -Note also that because Builder calls return -a list-like object, not an actual Python list, -you should -.I not -use the Python -.B += -operator to append Builder results to a Python list. -Because the list and the object are different types, -Python will not update the original list in place, -but will instead create a new Node-list object -containing the concatenation of the list -elements and the Builder results. -This will cause problems for any other Python variables -in your SCons configuration -that still hold on to a reference to the original list. -Instead, use the Python -.B .extend() -method to make sure the list is updated in-place. -Example: - -.ES -object_files = [] - -# Do NOT use += as follows: -# -# object_files += Object('bar.c') -# -# It will not update the object_files list in place. -# -# Instead, use the .extend() method: -object_files.extend(Object('bar.c')) - -.EE - -The path name for a Node's file may be used -by passing the Node to the Python-builtin -.B str() -function: - -.ES -bar_obj_list = env.StaticObject('bar.c', CPPDEFINES='-DBAR') -print "The path to bar_obj is:", str(bar_obj_list[0]) -.EE - -Note again that because the Builder call returns a list, -we have to access the first element in the list -.B (bar_obj_list[0]) -to get at the Node that actually represents -the object file. - -Builder calls support a -.B chdir -keyword argument that -specifies that the Builder's action(s) -should be executed -after changing directory. -If the -.B chdir -argument is -a string or a directory Node, -scons will change to the specified directory. -If the -.B chdir -is not a string or Node -and is non-zero, -then scons will change to the -target file's directory. - -.ES -# scons will change to the "sub" subdirectory -# before executing the "cp" command. -env.Command('sub/dir/foo.out', 'sub/dir/foo.in', - "cp dir/foo.in dir/foo.out", - chdir='sub') - -# Because chdir is not a string, scons will change to the -# target's directory ("sub/dir") before executing the -# "cp" command. -env.Command('sub/dir/foo.out', 'sub/dir/foo.in', - "cp foo.in foo.out", - chdir=1) -.EE - -Note that scons will -.I not -automatically modify -its expansion of -construction variables like -.B $TARGET -and -.B $SOURCE -when using the chdir -keyword argument--that is, -the expanded file names -will still be relative to -the top-level SConstruct directory, -and consequently incorrect -relative to the chdir directory. -If you use the chdir keyword argument, -you will typically need to supply a different -command line using -expansions like -.B ${TARGET.file} -and -.B ${SOURCE.file} -to use just the filename portion of the -targets and source. - -.B scons -provides the following builder methods: - -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -'\" BEGIN GENERATED BUILDER DESCRIPTIONS -'\" -'\" The descriptions below of the various SCons Builders are generated -'\" from the .xml files that live next to the various Python modules in -'\" the build enginer library. If you're reading this [gnt]roff file -'\" with an eye towards patching this man page, you can still submit -'\" a diff against this text, but it will have to be translated to a -'\" diff against the underlying .xml file before the patch is actually -'\" accepted. If you do that yourself, it will make it easier to -'\" integrate the patch. -'\" -'\" BEGIN GENERATED BUILDER DESCRIPTIONS -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.so builders.man -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -'\" END GENERATED BUILDER DESCRIPTIONS -'\" -'\" The descriptions above of the various SCons Builders are generated -'\" from the .xml files that live next to the various Python modules in -'\" the build enginer library. If you're reading this [gnt]roff file -'\" with an eye towards patching this man page, you can still submit -'\" a diff against this text, but it will have to be translated to a -'\" diff against the underlying .xml file before the patch is actually -'\" accepted. If you do that yourself, it will make it easier to -'\" integrate the patch. -'\" -'\" END GENERATED BUILDER DESCRIPTIONS -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" - -.P -All -targets of builder methods automatically depend on their sources. -An explicit dependency can -be specified using the -.B Depends -method of a construction environment (see below). - -In addition, -.B scons -automatically scans -source files for various programming languages, -so the dependencies do not need to be specified explicitly. -By default, SCons can -C source files, -C++ source files, -Fortran source files with -.B .F -(POSIX systems only), -.B .fpp, -or -.B .FPP -file extensions, -and assembly language files with -.B .S -(POSIX systems only), -.B .spp, -or -.B .SPP -files extensions -for C preprocessor dependencies. -SCons also has default support -for scanning D source files, -You can also write your own Scanners -to add support for additional source file types. -These can be added to the default -Scanner object used by the -.BR Object (), -.BR StaticObject (), -and -.BR SharedObject () -Builders by adding them -to the -.B SourceFileScanner -object. -See the section "Scanner Objects" -below, for more information about -defining your own Scanner objects -and using the -.B SourceFileScanner -object. - -.SS Methods and Functions to Do Things -In addition to Builder methods, -.B scons -provides a number of other construction environment methods -and global functions to -manipulate the build configuration. - -Usually, a construction environment method -and global function with the same name both exist -so that you don't have to remember whether -to a specific bit of functionality -must be called with or without a construction environment. -In the following list, -if you call something as a global function -it looks like: -.ES -.RI Function( arguments ) -.EE -and if you call something through a construction -environment it looks like: -.ES -.RI env.Function( arguments ) -.EE -If you can call the functionality in both ways, -then both forms are listed. - -Global functions may be called from custom Python modules that you -import into an SConscript file by adding the following -to the Python module: - -.ES -from SCons.Script import * -.EE - -Except where otherwise noted, -the same-named -construction environment method -and global function -provide the exact same functionality. -The only difference is that, -where appropriate, -calling the functionality through a construction environment will -substitute construction variables into -any supplied strings. -For example: - -.ES -env = Environment(FOO = 'foo') -Default('$FOO') -env.Default('$FOO') -.EE - -In the above example, -the first call to the global -.B Default() -function will actually add a target named -.B $FOO -to the list of default targets, -while the second call to the -.B env.Default() -construction environment method -will expand the value -and add a target named -.B foo -to the list of default targets. -For more on construction variable expansion, -see the next section on -construction variables. - -Construction environment methods -and global functions supported by -.B scons -include: - -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -'\" BEGIN GENERATED FUNCTION DESCRIPTIONS -'\" -'\" The descriptions below of the various SCons functions are generated -'\" from the .xml files that live next to the various Python modules in -'\" the build enginer library. If you're reading this [gnt]roff file -'\" with an eye towards patching this man page, you can still submit -'\" a diff against this text, but it will have to be translated to a -'\" diff against the underlying .xml file before the patch is actually -'\" accepted. If you do that yourself, it will make it easier to -'\" integrate the patch. -'\" -'\" BEGIN GENERATED FUNCTION DESCRIPTIONS -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.so functions.man -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -'\" END GENERATED FUNCTION DESCRIPTIONS -'\" -'\" The descriptions above of the various SCons functions are generated -'\" from the .xml files that live next to the various Python modules in -'\" the build enginer library. If you're reading this [gnt]roff file -'\" with an eye towards patching this man page, you can still submit -'\" a diff against this text, but it will have to be translated to a -'\" diff against the underlying .xml file before the patch is actually -'\" accepted. If you do that yourself, it will make it easier to -'\" integrate the patch. -'\" -'\" END GENERATED FUNCTION DESCRIPTIONS -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" - -.SS SConscript Variables -In addition to the global functions and methods, -.B scons -supports a number of Python variables -that can be used in SConscript files -to affect how you want the build to be performed. -These variables may be accessed from custom Python modules that you -import into an SConscript file by adding the following -to the Python module: - -.ES -from SCons.Script import * -.EE - -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.TP -ARGLIST -A list -.IR keyword = value -arguments specified on the command line. -Each element in the list is a tuple -containing the -.RI ( keyword , value ) -of the argument. -The separate -.I keyword -and -.I value -elements of the tuple -can be accessed by -subscripting for element -.B [0] -and -.B [1] -of the tuple, respectively. - -Example: - -.ES -print "first keyword, value =", ARGLIST[0][0], ARGLIST[0][1] -print "second keyword, value =", ARGLIST[1][0], ARGLIST[1][1] -third_tuple = ARGLIST[2] -print "third keyword, value =", third_tuple[0], third_tuple[1] -for key, value in ARGLIST: - # process key and value -.EE - -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.TP -ARGUMENTS -A dictionary of all the -.IR keyword = value -arguments specified on the command line. -The dictionary is not in order, -and if a given keyword has -more than one value assigned to it -on the command line, -the last (right-most) value is -the one in the -.B ARGUMENTS -dictionary. - -Example: - -.ES -if ARGUMENTS.get('debug', 0): - env = Environment(CCFLAGS = '-g') -else: - env = Environment() -.EE - -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.TP -BUILD_TARGETS -A list of the targets which -.B scons -will actually try to build, -regardless of whether they were specified on -the command line or via the -.BR Default () -function or method. -The elements of this list may be strings -.I or -nodes, so you should run the list through the Python -.B str -function to make sure any Node path names -are converted to strings. - -Because this list may be taken from the -list of targets specified using the -.BR Default () -function or method, -the contents of the list may change -on each successive call to -.BR Default (). -See the -.B DEFAULT_TARGETS -list, below, -for additional information. - -Example: - -.ES -if 'foo' in BUILD_TARGETS: - print "Don't forget to test the `foo' program!" -if 'special/program' in BUILD_TARGETS: - SConscript('special') -.EE -.IP -Note that the -.B BUILD_TARGETS -list only contains targets expected listed -on the command line or via calls to the -.BR Default () -function or method. -It does -.I not -contain all dependent targets that will be built as -a result of making the sure the explicitly-specified -targets are up to date. - -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.TP -COMMAND_LINE_TARGETS -A list of the targets explicitly specified on -the command line. -If there are no targets specified on the command line, -the list is empty. -This can be used, for example, -to take specific actions only -when a certain target or targets -is explicitly being built. - -Example: - -.ES -if 'foo' in COMMAND_LINE_TARGETS: - print "Don't forget to test the `foo' program!" -if 'special/program' in COMMAND_LINE_TARGETS: - SConscript('special') -.EE - -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.TP -DEFAULT_TARGETS -A list of the target -.I nodes -that have been specified using the -.BR Default () -function or method. -The elements of the list are nodes, -so you need to run them through the Python -.B str -function to get at the path name for each Node. - -Example: - -.ES -print str(DEFAULT_TARGETS[0]) -if 'foo' in map(str, DEFAULT_TARGETS): - print "Don't forget to test the `foo' program!" -.EE -.IP -The contents of the -.B DEFAULT_TARGETS -list change on on each successive call to the -.BR Default () -function: - -.ES -print map(str, DEFAULT_TARGETS) # originally [] -Default('foo') -print map(str, DEFAULT_TARGETS) # now a node ['foo'] -Default('bar') -print map(str, DEFAULT_TARGETS) # now a node ['foo', 'bar'] -Default(None) -print map(str, DEFAULT_TARGETS) # back to [] -.EE -.IP -Consequently, be sure to use -.B DEFAULT_TARGETS -only after you've made all of your -.BR Default () -calls, -or else simply be careful of the order -of these statements in your SConscript files -so that you don't look for a specific -default target before it's actually been added to the list. - -.SS Construction Variables -.\" XXX From Gary Ruben, 23 April 2002: -.\" I think it would be good to have an example with each construction -.\" variable description in the documentation. -.\" eg. -.\" CC The C compiler -.\" Example: env["CC"] = "c68x" -.\" Default: env["CC"] = "cc" -.\" -.\" CCCOM The command line ... -.\" Example: -.\" To generate the compiler line c68x -ps -qq -mr -o $TARGET $SOURCES -.\" env["CC"] = "c68x" -.\" env["CFLAGS"] = "-ps -qq -mr" -.\" env["CCCOM"] = "$CC $CFLAGS -o $TARGET $SOURCES -.\" Default: -.\" (I dunno what this is ;-) -A construction environment has an associated dictionary of -.I construction variables -that are used by built-in or user-supplied build rules. -Construction variables must follow the same rules for -Python identifiers: -the initial character must be an underscore or letter, -followed by any number of underscores, letters, or digits. - -A number of useful construction variables are automatically defined by -scons for each supported platform, and additional construction variables -can be defined by the user. The following is a list of the automatically -defined construction variables: - -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -'\" BEGIN GENERATED CONSTRUCTION VARIABLE DESCRIPTIONS -'\" -'\" The descriptions below of the various SCons construction variables -'\" are generated from the .xml files that live next to the various -'\" Python modules in the build enginer library. If you're reading -'\" this [gnt]roff file with an eye towards patching this man page, -'\" you can still submit a diff against this text, but it will have to -'\" be translated to a diff against the underlying .xml file before the -'\" patch is actually accepted. If you do that yourself, it will make -'\" it easier to integrate the patch. -'\" -'\" BEGIN GENERATED CONSTRUCTION VARIABLE DESCRIPTIONS -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -.so variables.man -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" -'\" END GENERATED CONSTRUCTION VARIABLE DESCRIPTIONS -'\" -'\" The descriptions above of the various SCons construction variables -'\" are generated from the .xml files that live next to the various -'\" Python modules in the build enginer library. If you're reading -'\" this [gnt]roff file with an eye towards patching this man page, -'\" you can still submit a diff against this text, but it will have to -'\" be translated to a diff against the underlying .xml file before the -'\" patch is actually accepted. If you do that yourself, it will make -'\" it easier to integrate the patch. -'\" -'\" END GENERATED CONSTRUCTION VARIABLE DESCRIPTIONS -'\""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""""" - -.LP -Construction variables can be retrieved and set using the -.B Dictionary -method of the construction environment: - -.ES -dict = env.Dictionary() -dict["CC"] = "cc" -.EE - -or using the [] operator: - -.ES -env["CC"] = "cc" -.EE - -Construction variables can also be passed to the construction environment -constructor: - -.ES -env = Environment(CC="cc") -.EE - -or when copying a construction environment using the -.B Clone -method: - -.ES -env2 = env.Clone(CC="cl.exe") -.EE - -.SS Configure Contexts - -.B scons -supports -.I configure contexts, -an integrated mechanism similar to the -various AC_CHECK macros in GNU autoconf -for testing for the existence of C header -files, libraries, etc. -In contrast to autoconf, -.B scons -does not maintain an explicit cache of the tested values, -but uses its normal dependency tracking to keep the checked values -up to date. However, users may override this behaviour with the -.B --config -command line option. - -The following methods can be used to perform checks: - -.TP -.RI Configure( env ", [" custom_tests ", " conf_dir ", " log_file ", " config_h ", " clean ", " help]) -.TP -.RI env.Configure([ custom_tests ", " conf_dir ", " log_file ", " config_h ", " clean ", " help]) -This creates a configure context, which can be used to perform checks. -.I env -specifies the environment for building the tests. -This environment may be modified when performing checks. -.I custom_tests -is a dictionary containing custom tests. -See also the section about custom tests below. -By default, no custom tests are added to the configure context. -.I conf_dir -specifies a directory where the test cases are built. -Note that this directory is not used for building -normal targets. -The default value is the directory -#/.sconf_temp. -.I log_file -specifies a file which collects the output from commands -that are executed to check for the existence of header files, libraries, etc. -The default is the file #/config.log. -If you are using the -.BR VariantDir () -method, -you may want to specify a subdirectory under your variant directory. -.I config_h -specifies a C header file where the results of tests -will be written, e.g. #define HAVE_STDIO_H, #define HAVE_LIBM, etc. -The default is to not write a -.B config.h -file. -You can specify the same -.B config.h -file in multiple calls to Configure, -in which case -.B scons -will concatenate all results in the specified file. -Note that SCons -uses its normal dependency checking -to decide if it's necessary to rebuild -the specified -.I config_h -file. -This means that the file is not necessarily re-built each -time scons is run, -but is only rebuilt if its contents will have changed -and some target that depends on the -.I config_h -file is being built. - -The optional -.B clean -and -.B help -arguments can be used to suppress execution of the configuration -tests when the -.B -c/--clean -or -.B -H/-h/--help -options are used, respectively. -The default behavior is always to execute -configure context tests, -since the results of the tests may -affect the list of targets to be cleaned -or the help text. -If the configure tests do not affect these, -then you may add the -.B clean=False -or -.B help=False -arguments -(or both) -to avoid unnecessary test execution. - -.EE -A created -.B Configure -instance has the following associated methods: - -.TP -.RI SConf.Finish( context ) -.TP -.IR sconf .Finish() -This method should be called after configuration is done. -It returns the environment as modified -by the configuration checks performed. -After this method is called, no further checks can be performed -with this configuration context. -However, you can create a new -.RI Configure -context to perform additional checks. -Only one context should be active at a time. - -The following Checks are predefined. -(This list will likely grow larger as time -goes by and developers contribute new useful tests.) - -.TP -.RI SConf.CheckHeader( context ", " header ", [" include_quotes ", " language ]) -.TP -.IR sconf .CheckHeader( header ", [" include_quotes ", " language ]) -Checks if -.I header -is usable in the specified language. -.I header -may be a list, -in which case the last item in the list -is the header file to be checked, -and the previous list items are -header files whose -.B #include -lines should precede the -header line being checked for. -The optional argument -.I include_quotes -must be -a two character string, where the first character denotes the opening -quote and the second character denotes the closing quote. -By default, both characters are " (double quote). -The optional argument -.I language -should be either -.B C -or -.B C++ -and selects the compiler to be used for the check. -Returns 1 on success and 0 on failure. - -.TP -.RI SConf.CheckCHeader( context ", " header ", [" include_quotes ]) -.TP -.IR sconf .CheckCHeader( header ", [" include_quotes ]) -This is a wrapper around -.B SConf.CheckHeader -which checks if -.I header -is usable in the C language. -.I header -may be a list, -in which case the last item in the list -is the header file to be checked, -and the previous list items are -header files whose -.B #include -lines should precede the -header line being checked for. -The optional argument -.I include_quotes -must be -a two character string, where the first character denotes the opening -quote and the second character denotes the closing quote (both default -to \N'34'). -Returns 1 on success and 0 on failure. - -.TP -.RI SConf.CheckCXXHeader( context ", " header ", [" include_quotes ]) -.TP -.IR sconf .CheckCXXHeader( header ", [" include_quotes ]) -This is a wrapper around -.B SConf.CheckHeader -which checks if -.I header -is usable in the C++ language. -.I header -may be a list, -in which case the last item in the list -is the header file to be checked, -and the previous list items are -header files whose -.B #include -lines should precede the -header line being checked for. -The optional argument -.I include_quotes -must be -a two character string, where the first character denotes the opening -quote and the second character denotes the closing quote (both default -to \N'34'). -Returns 1 on success and 0 on failure. - -.TP -.RI SConf.CheckFunc( context, ", " function_name ", [" header ", " language ]) -.TP -.IR sconf .CheckFunc( function_name ", [" header ", " language ]) -Checks if the specified -C or C++ function is available. -.I function_name -is the name of the function to check for. -The optional -.I header -argument is a string -that will be -placed at the top -of the test file -that will be compiled -to check if the function exists; -the default is: -.ES -#ifdef __cplusplus -extern "C" -#endif -char function_name(); -.EE -The optional -.I language -argument should be -.B C -or -.B C++ -and selects the compiler to be used for the check; -the default is "C". - -.TP -.RI SConf.CheckLib( context ", [" library ", " symbol ", " header ", " language ", " autoadd=1 ]) -.TP -.IR sconf .CheckLib([ library ", " symbol ", " header ", " language ", " autoadd=1 ]) -Checks if -.I library -provides -.IR symbol . -If the value of -.I autoadd -is 1 and the library provides the specified -.IR symbol , -appends the library to the LIBS construction environment variable. -.I library -may also be None (the default), -in which case -.I symbol -is checked with the current LIBS variable, -or a list of library names, -in which case each library in the list -will be checked for -.IR symbol . -If -.I symbol -is not set or is -.BR None , -then -.BR SConf.CheckLib () -just checks if -you can link against the specified -.IR library . -The optional -.I language -argument should be -.B C -or -.B C++ -and selects the compiler to be used for the check; -the default is "C". -The default value for -.I autoadd -is 1. -This method returns 1 on success and 0 on error. - -.TP -.RI SConf.CheckLibWithHeader( context ", " library ", " header ", " language ", [" call ", " autoadd ]) -.TP -.IR sconf .CheckLibWithHeader( library ", " header ", " language ", [" call ", " autoadd ]) - -In contrast to the -.RI SConf.CheckLib -call, this call provides a more sophisticated way to check against libraries. -Again, -.I library -specifies the library or a list of libraries to check. -.I header -specifies a header to check for. -.I header -may be a list, -in which case the last item in the list -is the header file to be checked, -and the previous list items are -header files whose -.B #include -lines should precede the -header line being checked for. -.I language -may be one of 'C','c','CXX','cxx','C++' and 'c++'. -.I call -can be any valid expression (with a trailing ';'). -If -.I call -is not set, -the default simply checks that you -can link against the specified -.IR library . -.I autoadd -specifies whether to add the library to the environment (only if the check -succeeds). This method returns 1 on success and 0 on error. - -.TP -.RI SConf.CheckType( context ", " type_name ", [" includes ", " language ]) -.TP -.IR sconf .CheckType( type_name ", [" includes ", " language ]) -Checks for the existence of a type defined by -.BR typedef . -.I type_name -specifies the typedef name to check for. -.I includes -is a string containing one or more -.B #include -lines that will be inserted into the program -that will be run to test for the existence of the type. -The optional -.I language -argument should be -.B C -or -.B C++ -and selects the compiler to be used for the check; -the default is "C". -Example: -.ES -sconf.CheckType('foo_type', '#include "my_types.h"', 'C++') -.EE - -.TP -.RI Configure.CheckCC( self ) -Checks whether the C compiler (as defined by the CC construction variable) works -by trying to compile a small source file. - -By default, SCons only detects if there is a program with the correct name, not -if it is a functioning compiler. - -This uses the exact same command than the one used by the object builder for C -source file, so it can be used to detect if a particular compiler flag works or -not. - -.TP -.RI Configure.CheckCXX( self ) -Checks whether the C++ compiler (as defined by the CXX construction variable) -works by trying to compile a small source file. By default, SCons only detects -if there is a program with the correct name, not if it is a functioning compiler. - -This uses the exact same command than the one used by the object builder for -CXX source files, so it can be used to detect if a particular compiler flag -works or not. - -.TP -.RI Configure.CheckSHCC( self ) -Checks whether the C compiler (as defined by the SHCC construction variable) works -by trying to compile a small source file. By default, SCons only detects if -there is a program with the correct name, not if it is a functioning compiler. - -This uses the exact same command than the one used by the object builder for C -source file, so it can be used to detect if a particular compiler flag works or -not. This does not check whether the object code can be used to build a shared -library, only that the compilation (not link) succeeds. - -.TP -.RI Configure.CheckSHCXX( self ) -Checks whether the C++ compiler (as defined by the SHCXX construction variable) -works by trying to compile a small source file. By default, SCons only detects -if there is a program with the correct name, not if it is a functioning compiler. - -This uses the exact same command than the one used by the object builder for -CXX source files, so it can be used to detect if a particular compiler flag -works or not. This does not check whether the object code can be used to build -a shared library, only that the compilation (not link) succeeds. - -.EE -Example of a typical Configure usage: - -.ES -env = Environment() -conf = Configure( env ) -if not conf.CheckCHeader( 'math.h' ): - print 'We really need math.h!' - Exit(1) -if conf.CheckLibWithHeader( 'qt', 'qapp.h', 'c++', - 'QApplication qapp(0,0);' ): - # do stuff for qt - usage, e.g. - conf.env.Append( CPPFLAGS = '-DWITH_QT' ) -env = conf.Finish() -.EE - -.TP -.RI SConf.CheckTypeSize( context ", " type_name ", [" header ", " language ", " expect ]) -.TP -.IR sconf .CheckTypeSize( type_name ", [" header ", " language ", " expect ]) -Checks for the size of a type defined by -.BR typedef . -.I type_name -specifies the typedef name to check for. -The optional -.I header -argument is a string -that will be -placed at the top -of the test file -that will be compiled -to check if the function exists; -the default is empty. -The optional -.I language -argument should be -.B C -or -.B C++ -and selects the compiler to be used for the check; -the default is "C". -The optional -.I expect -argument should be an integer. -If this argument is used, -the function will only check whether the type -given in type_name has the expected size (in bytes). -For example, -.B "CheckTypeSize('short', expect = 2)" -will return success only if short is two bytes. - -.ES -.EE - -.TP -.RI SConf.CheckDeclaration( context ", " symbol ", [" includes ", " language ]) -.TP -.IR sconf .CheckDeclaration( symbol ", [" includes ", " language ]) -Checks if the specified -.I symbol -is declared. -.I includes -is a string containing one or more -.B #include -lines that will be inserted into the program -that will be run to test for the existence of the type. -The optional -.I language -argument should be -.B C -or -.B C++ -and selects the compiler to be used for the check; -the default is "C". - -.TP -.RI SConf.Define( context ", " symbol ", [" value ", " comment ]) -.TP -.IR sconf .Define( symbol ", [" value ", " comment ]) -This function does not check for anything, but defines a -preprocessor symbol that will be added to the configuration header file. -It is the equivalent of AC_DEFINE, -and defines the symbol -.I name -with the optional -.B value -and the optional comment -.BR comment . - -.IP -Examples: - -.ES -env = Environment() -conf = Configure( env ) - -# Puts the following line in the config header file: -# #define A_SYMBOL -conf.Define('A_SYMBOL') - -# Puts the following line in the config header file: -# #define A_SYMBOL 1 -conf.Define('A_SYMBOL', 1) -.EE - -.IP -Be careful about quoting string values, though: - -.ES -env = Environment() -conf = Configure( env ) - -# Puts the following line in the config header file: -# #define A_SYMBOL YA -conf.Define('A_SYMBOL', "YA") - -# Puts the following line in the config header file: -# #define A_SYMBOL "YA" -conf.Define('A_SYMBOL', '"YA"') -.EE - -.IP -For comment: - -.ES -env = Environment() -conf = Configure( env ) - -# Puts the following lines in the config header file: -# /* Set to 1 if you have a symbol */ -# #define A_SYMBOL 1 -conf.Define('A_SYMBOL', 1, 'Set to 1 if you have a symbol') -.EE - -.EE -You can define your own custom checks. -in addition to the predefined checks. -These are passed in a dictionary to the Configure function. -This dictionary maps the names of the checks -to user defined Python callables -(either Python functions or class instances implementing the -.I __call__ -method). -The first argument of the call is always a -.I CheckContext -instance followed by the arguments, -which must be supplied by the user of the check. -These CheckContext instances define the following methods: - -.TP -.RI CheckContext.Message( self ", " text ) - -Usually called before the check is started. -.I text -will be displayed to the user, e.g. 'Checking for library X...' - -.TP -.RI CheckContext.Result( self, ", " res ) - -Usually called after the check is done. -.I res -can be either an integer or a string. In the former case, 'yes' (res != 0) -or 'no' (res == 0) is displayed to the user, in the latter case the -given string is displayed. - -.TP -.RI CheckContext.TryCompile( self ", " text ", " extension ) -Checks if a file with the specified -.I extension -(e.g. '.c') containing -.I text -can be compiled using the environment's -.B Object -builder. Returns 1 on success and 0 on failure. - -.TP -.RI CheckContext.TryLink( self ", " text ", " extension ) -Checks, if a file with the specified -.I extension -(e.g. '.c') containing -.I text -can be compiled using the environment's -.B Program -builder. Returns 1 on success and 0 on failure. - -.TP -.RI CheckContext.TryRun( self ", " text ", " extension ) -Checks, if a file with the specified -.I extension -(e.g. '.c') containing -.I text -can be compiled using the environment's -.B Program -builder. On success, the program is run. If the program -executes successfully -(that is, its return status is 0), -a tuple -.I (1, outputStr) -is returned, where -.I outputStr -is the standard output of the -program. -If the program fails execution -(its return status is non-zero), -then (0, '') is returned. - -.TP -.RI CheckContext.TryAction( self ", " action ", [" text ", " extension ]) -Checks if the specified -.I action -with an optional source file (contents -.I text -, extension -.I extension -= '' -) can be executed. -.I action -may be anything which can be converted to a -.B scons -.RI Action. -On success, -.I (1, outputStr) -is returned, where -.I outputStr -is the content of the target file. -On failure -.I (0, '') -is returned. - -.TP -.RI CheckContext.TryBuild( self ", " builder ", [" text ", " extension ]) -Low level implementation for testing specific builds; -the methods above are based on this method. -Given the Builder instance -.I builder -and the optional -.I text -of a source file with optional -.IR extension , -this method returns 1 on success and 0 on failure. In addition, -.I self.lastTarget -is set to the build target node, if the build was successful. - -.EE -Example for implementing and using custom tests: - -.ES -def CheckQt(context, qtdir): - context.Message( 'Checking for qt ...' ) - lastLIBS = context.env['LIBS'] - lastLIBPATH = context.env['LIBPATH'] - lastCPPPATH= context.env['CPPPATH'] - context.env.Append(LIBS = 'qt', LIBPATH = qtdir + '/lib', CPPPATH = qtdir + '/include' ) - ret = context.TryLink(""" -#include <qapp.h> -int main(int argc, char **argv) { - QApplication qapp(argc, argv); - return 0; -} -""") - if not ret: - context.env.Replace(LIBS = lastLIBS, LIBPATH=lastLIBPATH, CPPPATH=lastCPPPATH) - context.Result( ret ) - return ret - -env = Environment() -conf = Configure( env, custom_tests = { 'CheckQt' : CheckQt } ) -if not conf.CheckQt('/usr/lib/qt'): - print 'We really need qt!' - Exit(1) -env = conf.Finish() -.EE - -.SS Command-Line Construction Variables - -Often when building software, -some variables must be specified at build time. -For example, libraries needed for the build may be in non-standard -locations, or site-specific compiler options may need to be passed to the -compiler. -.B scons -provides a -.B Variables -object to support overriding construction variables -on the command line: -.ES -$ scons VARIABLE=foo -.EE -The variable values can also be specified in a text-based SConscript file. -To create a Variables object, call the Variables() function: - -.TP -.RI Variables([ files "], [" args ]) -This creates a Variables object that will read construction variables from -the file or list of filenames specified in -.IR files . -If no files are specified, -or the -.I files -argument is -.BR None , -then no files will be read. -The optional argument -.I args -is a dictionary of -values that will override anything read from the specified files; -it is primarily intended to be passed the -.B ARGUMENTS -dictionary that holds variables -specified on the command line. -Example: - -.ES -vars = Variables('custom.py') -vars = Variables('overrides.py', ARGUMENTS) -vars = Variables(None, {FOO:'expansion', BAR:7}) -.EE - -Variables objects have the following methods: - -.TP -.RI Add( key ", [" help ", " default ", " validator ", " converter ]) -This adds a customizable construction variable to the Variables object. -.I key -is the name of the variable. -.I help -is the help text for the variable. -.I default -is the default value of the variable; -if the default value is -.B None -and there is no explicit value specified, -the construction variable will -.I not -be added to the construction environment. -.I validator -is called to validate the value of the variable, and should take three -arguments: key, value, and environment. -The recommended way to handle an invalid value is -to raise an exception (see example below). -.I converter -is called to convert the value before putting it in the environment, and -should take either a value, or the value and environment, as parameters. -The -.I converter -must return a value, -which will be converted into a string -before being validated by the -.I validator -(if any) -and then added to the environment. - -Examples: - -.ES -vars.Add('CC', 'The C compiler') - -def validate_color(key, val, env): - if not val in ['red', 'blue', 'yellow']: - raise Exception("Invalid color value '%s'" % val) -vars.Add('COLOR', validator=valid_color) -.EE - -.TP -.RI AddVariables( list ) -A wrapper script that adds -multiple customizable construction variables -to a Variables object. -.I list -is a list of tuple or list objects -that contain the arguments -for an individual call to the -.B Add -method. - -.ES -opt.AddVariables( - ('debug', '', 0), - ('CC', 'The C compiler'), - ('VALIDATE', 'An option for testing validation', - 'notset', validator, None), - ) -.EE - -.TP -.RI Update( env ", [" args ]) -This updates a construction environment -.I env -with the customized construction variables. -Any specified variables that are -.I not -configured for the Variables object -will be saved and may be -retrieved with the -.BR UnknownVariables () -method, below. - -Normally this method is not called directly, -but is called indirectly by passing the Variables object to -the Environment() function: - -.ES -env = Environment(variables=vars) -.EE - -.IP -The text file(s) that were specified -when the Variables object was created -are executed as Python scripts, -and the values of (global) Python variables set in the file -are added to the construction environment. - -Example: - -.ES -CC = 'my_cc' -.EE - -.TP -.RI UnknownVariables( ) -Returns a dictionary containing any -variables that were specified -either in the files or the dictionary -with which the Variables object was initialized, -but for which the Variables object was -not configured. - -.ES -env = Environment(variables=vars) -for key, value in vars.UnknownVariables(): - print "unknown variable: %s=%s" % (key, value) -.EE - -.TP -.RI Save( filename ", " env ) -This saves the currently set variables into a script file named -.I filename -that can be used on the next invocation to automatically load the current -settings. This method combined with the Variables method can be used to -support caching of variables between runs. - -.ES -env = Environment() -vars = Variables(['variables.cache', 'custom.py']) -vars.Add(...) -vars.Update(env) -vars.Save('variables.cache', env) -.EE - -.TP -.RI GenerateHelpText( env ", [" sort ]) -This generates help text documenting the customizable construction -variables suitable to passing in to the Help() function. -.I env -is the construction environment that will be used to get the actual values -of customizable variables. Calling with -an optional -.I sort -function -will cause the output to be sorted -by the specified argument. -The specific -.I sort -function -should take two arguments -and return --1, 0 or 1 -(like the standard Python -.I cmp -function). - -.ES -Help(vars.GenerateHelpText(env)) -Help(vars.GenerateHelpText(env, sort=cmp)) -.EE - -.TP -.RI FormatVariableHelpText( env ", " opt ", " help ", " default ", " actual ) -This method returns a formatted string -containing the printable help text -for one option. -It is normally not called directly, -but is called by the -.IR GenerateHelpText () -method to create the returned help text. -It may be overridden with your own -function that takes the arguments specified above -and returns a string of help text formatted to your liking. -Note that the -.IR GenerateHelpText () -will not put any blank lines or extra -characters in between the entries, -so you must add those characters to the returned -string if you want the entries separated. - -.ES -def my_format(env, opt, help, default, actual): - fmt = "\n%s: default=%s actual=%s (%s)\n" - return fmt % (opt, default. actual, help) -vars.FormatVariableHelpText = my_format -.EE - -To make it more convenient to work with customizable Variables, -.B scons -provides a number of functions -that make it easy to set up -various types of Variables: - -.TP -.RI BoolVariable( key ", " help ", " default ) -Return a tuple of arguments -to set up a Boolean option. -The option will use -the specified name -.IR key , -have a default value of -.IR default , -and display the specified -.I help -text. -The option will interpret the values -.BR y , -.BR yes , -.BR t , -.BR true , -.BR 1 , -.B on -and -.B all -as true, -and the values -.BR n , -.BR no , -.BR f , -.BR false , -.BR 0 , -.B off -and -.B none -as false. - -.TP -.RI EnumVariable( key ", " help ", " default ", " allowed_values ", [" map ", " ignorecase ]) -Return a tuple of arguments -to set up an option -whose value may be one -of a specified list of legal enumerated values. -The option will use -the specified name -.IR key , -have a default value of -.IR default , -and display the specified -.I help -text. -The option will only support those -values in the -.I allowed_values -list. -The optional -.I map -argument is a dictionary -that can be used to convert -input values into specific legal values -in the -.I allowed_values -list. -If the value of -.I ignore_case -is -.B 0 -(the default), -then the values are case-sensitive. -If the value of -.I ignore_case -is -.BR 1 , -then values will be matched -case-insensitive. -If the value of -.I ignore_case -is -.BR 1 , -then values will be matched -case-insensitive, -and all input values will be -converted to lower case. - -.TP -.RI ListVariable( key ", " help ", " default ", " names ", [", map ]) -Return a tuple of arguments -to set up an option -whose value may be one or more -of a specified list of legal enumerated values. -The option will use -the specified name -.IR key , -have a default value of -.IR default , -and display the specified -.I help -text. -The option will only support the values -.BR all , -.BR none , -or the values in the -.I names -list. -More than one value may be specified, -with all values separated by commas. -The default may be a string of -comma-separated default values, -or a list of the default values. -The optional -.I map -argument is a dictionary -that can be used to convert -input values into specific legal values -in the -.I names -list. - -.TP -.RI PackageVariable( key ", " help ", " default ) -Return a tuple of arguments -to set up an option -whose value is a path name -of a package that may be -enabled, disabled or -given an explicit path name. -The option will use -the specified name -.IR key , -have a default value of -.IR default , -and display the specified -.I help -text. -The option will support the values -.BR yes , -.BR true , -.BR on , -.BR enable -or -.BR search , -in which case the specified -.I default -will be used, -or the option may be set to an -arbitrary string -(typically the path name to a package -that is being enabled). -The option will also support the values -.BR no , -.BR false , -.BR off -or -.BR disable -to disable use of the specified option. - -.TP -.RI PathVariable( key ", " help ", " default ", [" validator ]) -Return a tuple of arguments -to set up an option -whose value is expected to be a path name. -The option will use -the specified name -.IR key , -have a default value of -.IR default , -and display the specified -.I help -text. -An additional -.I validator -may be specified -that will be called to -verify that the specified path -is acceptable. -SCons supplies the -following ready-made validators: -.BR PathVariable.PathExists -(the default), -which verifies that the specified path exists; -.BR PathVariable.PathIsFile , -which verifies that the specified path is an existing file; -.BR PathVariable.PathIsDir , -which verifies that the specified path is an existing directory; -.BR PathVariable.PathIsDirCreate , -which verifies that the specified path is a directory -and will create the specified directory if the path does not exist; -and -.BR PathVariable.PathAccept , -which simply accepts the specific path name argument without validation, -and which is suitable if you want your users -to be able to specify a directory path that will be -created as part of the build process, for example. -You may supply your own -.I validator -function, -which must take three arguments -.RI ( key , -the name of the variable to be set; -.IR val , -the specified value being checked; -and -.IR env , -the construction environment) -and should raise an exception -if the specified value is not acceptable. - -.RE -These functions make it -convenient to create a number -of variables with consistent behavior -in a single call to the -.B AddVariables -method: - -.ES -vars.AddVariables( - BoolVariable('warnings', 'compilation with -Wall and similiar', 1), - EnumVariable('debug', 'debug output and symbols', 'no' - allowed_values=('yes', 'no', 'full'), - map={}, ignorecase=0), # case sensitive - ListVariable('shared', - 'libraries to build as shared libraries', - 'all', - names = list_of_libs), - PackageVariable('x11', - 'use X11 installed here (yes = search some places)', - 'yes'), - PathVariable('qtdir', 'where the root of Qt is installed', qtdir), - PathVariable('foopath', 'where the foo library is installed', foopath, - PathVariable.PathIsDir), - -) -.EE - -.SS File and Directory Nodes - -The -.IR File () -and -.IR Dir () -functions return -.I File -and -.I Dir -Nodes, respectively. -python objects, respectively. -Those objects have several user-visible attributes -and methods that are often useful: - -.IP path -The build path -of the given -file or directory. -This path is relative to the top-level directory -(where the -.B SConstruct -file is found). -The build path is the same as the source path if -.I variant_dir -is not being used. - -.IP abspath -The absolute build path of the given file or directory. - -.IP srcnode() -The -.IR srcnode () -method -returns another -.I File -or -.I Dir -object representing the -.I source -path of the given -.I File -or -.IR Dir . -The - -.ES -# Get the current build dir's path, relative to top. -Dir('.').path -# Current dir's absolute path -Dir('.').abspath -# Next line is always '.', because it is the top dir's path relative to itself. -Dir('#.').path -File('foo.c').srcnode().path # source path of the given source file. - -# Builders also return File objects: -foo = env.Program('foo.c') -print "foo will be built in %s"%foo.path -.EE - -A -.I Dir -Node or -.I File -Node can also be used to create -file and subdirectory Nodes relative to the generating Node. -A -.I Dir -Node will place the new Nodes within the directory it represents. -A -.I File -node will place the new Nodes within its parent directory -(that is, "beside" the file in question). -If -.I d -is a -.I Dir -(directory) Node and -.I f -is a -.I File -(file) Node, -then these methods are available: - -.TP -.IR d .Dir( name ) -Returns a directory Node for a subdirectory of -.I d -named -.IR name . - -.TP -.IR d .File( name ) -Returns a file Node for a file within -.I d -named -.IR name . - -.TP -.IR d .Entry( name ) -Returns an unresolved Node within -.I d -named -.IR name . - -.TP -.IR f .Dir( name ) -Returns a directory named -.I name -within the parent directory of -.IR f . - -.TP -.IR f .File( name ) -Returns a file named -.I name -within the parent directory of -.IR f . - -.TP -.IR f .Entry( name ) -Returns an unresolved Node named -.I name -within the parent directory of -.IR f . - -.RE -For example: - -.ES -# Get a Node for a file within a directory -incl = Dir('include') -f = incl.File('header.h') - -# Get a Node for a subdirectory within a directory -dist = Dir('project-3.2.1) -src = dist.Dir('src') - -# Get a Node for a file in the same directory -cfile = File('sample.c') -hfile = cfile.File('sample.h') - -# Combined example -docs = Dir('docs') -html = docs.Dir('html') -index = html.File('index.html') -css = index.File('app.css') -.EE - -.SH EXTENDING SCONS -.SS Builder Objects -.B scons -can be extended to build different types of targets -by adding new Builder objects -to a construction environment. -.IR "In general" , -you should only need to add a new Builder object -when you want to build a new type of file or other external target. -If you just want to invoke a different compiler or other tool -to build a Program, Object, Library, or any other -type of output file for which -.B scons -already has an existing Builder, -it is generally much easier to -use those existing Builders -in a construction environment -that sets the appropriate construction variables -(CC, LINK, etc.). - -Builder objects are created -using the -.B Builder -function. -The -.B Builder -function accepts the following arguments: - -.IP action -The command line string used to build the target from the source. -.B action -can also be: -a list of strings representing the command -to be executed and its arguments -(suitable for enclosing white space in an argument), -a dictionary -mapping source file name suffixes to -any combination of command line strings -(if the builder should accept multiple source file extensions), -a Python function; -an Action object -(see the next section); -or a list of any of the above. - -An action function -takes three arguments: -.I source -- a list of source nodes, -.I target -- a list of target nodes, -.I env -- the construction environment. - -.IP prefix -The prefix that will be prepended to the target file name. -This may be specified as a: - -.RS 10 -.HP 6 -* -.IR string , - -.HP 6 -* -.I callable object -- a function or other callable that takes -two arguments (a construction environment and a list of sources) -and returns a prefix, - -.HP 6 -* -.I dictionary -- specifies a mapping from a specific source suffix (of the first -source specified) to a corresponding target prefix. Both the source -suffix and target prefix specifications may use environment variable -substitution, and the target prefix (the 'value' entries in the -dictionary) may also be a callable object. The default target prefix -may be indicated by a dictionary entry with a key value of None. -.RE -.P - -.ES -b = Builder("build_it < $SOURCE > $TARGET", - prefix = "file-") - -def gen_prefix(env, sources): - return "file-" + env['PLATFORM'] + '-' -b = Builder("build_it < $SOURCE > $TARGET", - prefix = gen_prefix) - -b = Builder("build_it < $SOURCE > $TARGET", - suffix = { None: "file-", - "$SRC_SFX_A": gen_prefix }) -.EE - -.IP suffix -The suffix that will be appended to the target file name. -This may be specified in the same manner as the prefix above. -If the suffix is a string, then -.B scons -will append a '.' to the beginning of the suffix if it's not already -there. The string returned by callable object (or obtained from the -dictionary) is untouched and must append its own '.' to the beginning -if one is desired. - -.ES -b = Builder("build_it < $SOURCE > $TARGET" - suffix = "-file") - -def gen_suffix(env, sources): - return "." + env['PLATFORM'] + "-file" -b = Builder("build_it < $SOURCE > $TARGET", - suffix = gen_suffix) - -b = Builder("build_it < $SOURCE > $TARGET", - suffix = { None: ".sfx1", - "$SRC_SFX_A": gen_suffix }) -.EE - -.IP ensure_suffix -When set to any true value, causes -.B scons -to add the target suffix specified by the -.I suffix -keyword to any target strings -that have a different suffix. -(The default behavior is to leave untouched -any target file name that looks like it already has any suffix.) - -.ES -b1 = Builder("build_it < $SOURCE > $TARGET" - suffix = ".out") -b2 = Builder("build_it < $SOURCE > $TARGET" - suffix = ".out", - ensure_suffix) -env = Environment() -env['BUILDERS']['B1'] = b1 -env['BUILDERS']['B2'] = b2 - -# Builds "foo.txt" because ensure_suffix is not set. -env.B1('foo.txt', 'foo.in') - -# Builds "bar.txt.out" because ensure_suffix is set. -env.B2('bar.txt', 'bar.in') -.EE - -.IP src_suffix -The expected source file name suffix. This may be a string or a list -of strings. - -.IP target_scanner -A Scanner object that -will be invoked to find -implicit dependencies for this target file. -This keyword argument should be used -for Scanner objects that find -implicit dependencies -based only on the target file -and the construction environment, -.I not -for implicit dependencies based on source files. -(See the section "Scanner Objects" below, -for information about creating Scanner objects.) - -.IP source_scanner -A Scanner object that -will be invoked to -find implicit dependencies in -any source files -used to build this target file. -This is where you would -specify a scanner to -find things like -.B #include -lines in source files. -The pre-built -.B DirScanner -Scanner object may be used to -indicate that this Builder -should scan directory trees -for on-disk changes to files -that -.B scons -does not know about from other Builder or function calls. -(See the section "Scanner Objects" below, -for information about creating your own Scanner objects.) - -.IP target_factory -A factory function that the Builder will use -to turn any targets specified as strings into SCons Nodes. -By default, -SCons assumes that all targets are files. -Other useful target_factory -values include -.BR Dir , -for when a Builder creates a directory target, -and -.BR Entry , -for when a Builder can create either a file -or directory target. - -Example: - -.ES -MakeDirectoryBuilder = Builder(action=my_mkdir, target_factory=Dir) -env = Environment() -env.Append(BUILDERS = {'MakeDirectory':MakeDirectoryBuilder}) -env.MakeDirectory('new_directory', []) -.EE - -.IP -Note that the call to the MakeDirectory Builder -needs to specify an empty source list -to make the string represent the builder's target; -without that, it would assume the argument is the source, -and would try to deduce the target name from it, -which in the absence of an automatically-added prefix or suffix -would lead to a matching target and source name -and a circular dependency. - -.IP source_factory -A factory function that the Builder will use -to turn any sources specified as strings into SCons Nodes. -By default, -SCons assumes that all source are files. -Other useful source_factory -values include -.BR Dir , -for when a Builder uses a directory as a source, -and -.BR Entry , -for when a Builder can use files -or directories (or both) as sources. - -Example: - -.ES -CollectBuilder = Builder(action=my_mkdir, source_factory=Entry) -env = Environment() -env.Append(BUILDERS = {'Collect':CollectBuilder}) -env.Collect('archive', ['directory_name', 'file_name']) -.EE - -.IP emitter -A function or list of functions to manipulate the target and source -lists before dependencies are established -and the target(s) are actually built. -.B emitter -can also be a string containing a construction variable to expand -to an emitter function or list of functions, -or a dictionary mapping source file suffixes -to emitter functions. -(Only the suffix of the first source file -is used to select the actual emitter function -from an emitter dictionary.) - -An emitter function -takes three arguments: -.I source -- a list of source nodes, -.I target -- a list of target nodes, -.I env -- the construction environment. -An emitter must return a tuple containing two lists, -the list of targets to be built by this builder, -and the list of sources for this builder. - -Example: - -.ES -def e(target, source, env): - return (target + ['foo.foo'], source + ['foo.src']) - -# Simple association of an emitter function with a Builder. -b = Builder("my_build < $TARGET > $SOURCE", - emitter = e) - -def e2(target, source, env): - return (target + ['bar.foo'], source + ['bar.src']) - -# Simple association of a list of emitter functions with a Builder. -b = Builder("my_build < $TARGET > $SOURCE", - emitter = [e, e2]) - -# Calling an emitter function through a construction variable. -env = Environment(MY_EMITTER = e) -b = Builder("my_build < $TARGET > $SOURCE", - emitter = '$MY_EMITTER') - -# Calling a list of emitter functions through a construction variable. -env = Environment(EMITTER_LIST = [e, e2]) -b = Builder("my_build < $TARGET > $SOURCE", - emitter = '$EMITTER_LIST') - -# Associating multiple emitters with different file -# suffixes using a dictionary. -def e_suf1(target, source, env): - return (target + ['another_target_file'], source) -def e_suf2(target, source, env): - return (target, source + ['another_source_file']) -b = Builder("my_build < $TARGET > $SOURCE", - emitter = {'.suf1' : e_suf1, - '.suf2' : e_suf2}) -.EE - -.IP multi -Specifies whether this builder is allowed to be called multiple times for -the same target file(s). The default is 0, which means the builder -can not be called multiple times for the same target file(s). Calling a -builder multiple times for the same target simply adds additional source -files to the target; it is not allowed to change the environment associated -with the target, specify addition environment overrides, or associate a different -builder with the target. - -.IP env -A construction environment that can be used -to fetch source code using this Builder. -(Note that this environment is -.I not -used for normal builds of normal target files, -which use the environment that was -used to call the Builder for the target file.) - -.IP generator -A function that returns a list of actions that will be executed to build -the target(s) from the source(s). -The returned action(s) may be -an Action object, or anything that -can be converted into an Action object -(see the next section). - -The generator function -takes four arguments: -.I source -- a list of source nodes, -.I target -- a list of target nodes, -.I env -- the construction environment, -.I for_signature -- a Boolean value that specifies -whether the generator is being called -for generating a build signature -(as opposed to actually executing the command). -Example: - -.ES -def g(source, target, env, for_signature): - return [["gcc", "-c", "-o"] + target + source] - -b = Builder(generator=g) -.EE - -.IP -The -.I generator -and -.I action -arguments must not both be used for the same Builder. - -.IP src_builder -Specifies a builder to use when a source file name suffix does not match -any of the suffixes of the builder. Using this argument produces a -multi-stage builder. - -.IP single_source -Specifies that this builder expects exactly one source file per call. Giving -more than one source file without target files results in implicitely calling -the builder multiple times (once for each source given). Giving multiple -source files together with target files results in a UserError exception. - -.RE -.IP -The -.I generator -and -.I action -arguments must not both be used for the same Builder. - -.IP source_ext_match -When the specified -.I action -argument is a dictionary, -the default behavior when a builder is passed -multiple source files is to make sure that the -extensions of all the source files match. -If it is legal for this builder to be -called with a list of source files with different extensions, -this check can be suppressed by setting -.B source_ext_match -to -.B None -or some other non-true value. -When -.B source_ext_match -is disable, -.B scons -will use the suffix of the first specified -source file to select the appropriate action from the -.I action -dictionary. - -In the following example, -the setting of -.B source_ext_match -prevents -.B scons -from exiting with an error -due to the mismatched suffixes of -.B foo.in -and -.BR foo.extra . - -.ES -b = Builder(action={'.in' : 'build $SOURCES > $TARGET'}, - source_ext_match = None) - -env = Environment(BUILDERS = {'MyBuild':b}) -env.MyBuild('foo.out', ['foo.in', 'foo.extra']) -.EE - -.IP env -A construction environment that can be used -to fetch source code using this Builder. -(Note that this environment is -.I not -used for normal builds of normal target files, -which use the environment that was -used to call the Builder for the target file.) - -.ES -b = Builder(action="build < $SOURCE > $TARGET") -env = Environment(BUILDERS = {'MyBuild' : b}) -env.MyBuild('foo.out', 'foo.in', my_arg = 'xyzzy') -.EE - -.IP chdir -A directory from which scons -will execute the -action(s) specified -for this Builder. -If the -.B chdir -argument is -a string or a directory Node, -scons will change to the specified directory. -If the -.B chdir -is not a string or Node -and is non-zero, -then scons will change to the -target file's directory. - -Note that scons will -.I not -automatically modify -its expansion of -construction variables like -.B $TARGET -and -.B $SOURCE -when using the chdir -keyword argument--that is, -the expanded file names -will still be relative to -the top-level SConstruct directory, -and consequently incorrect -relative to the chdir directory. -Builders created using chdir keyword argument, -will need to use construction variable -expansions like -.B ${TARGET.file} -and -.B ${SOURCE.file} -to use just the filename portion of the -targets and source. - -.ES -b = Builder(action="build < ${SOURCE.file} > ${TARGET.file}", - chdir=1) -env = Environment(BUILDERS = {'MyBuild' : b}) -env.MyBuild('sub/dir/foo.out', 'sub/dir/foo.in') -.EE - -.B WARNING: -Python only keeps one current directory -location for all of the threads. -This means that use of the -.B chdir -argument -will -.I not -work with the SCons -.B -j -option, -because individual worker threads spawned -by SCons interfere with each other -when they start changing directory. - -.RE -Any additional keyword arguments supplied -when a Builder object is created -(that is, when the Builder() function is called) -will be set in the executing construction -environment when the Builder object is called. -The canonical example here would be -to set a construction variable to -the repository of a source code system. - -Any additional keyword arguments supplied -when a Builder -.I object -is called -will only be associated with the target -created by that particular Builder call -(and any other files built as a -result of the call). - -These extra keyword arguments are passed to the -following functions: -command generator functions, -function Actions, -and emitter functions. - -.SS Action Objects - -The -.BR Builder () -function will turn its -.B action -keyword argument into an appropriate -internal Action object. -You can also explicity create Action objects -using the -.BR Action () -global function, -which can then be passed to the -.BR Builder () -function. -This can be used to configure -an Action object more flexibly, -or it may simply be more efficient -than letting each separate Builder object -create a separate Action -when multiple -Builder objects need to do the same thing. - -The -.BR Action () -global function -returns an appropriate object for the action -represented by the type of the first argument: - -.IP Action -If the first argument is already an Action object, -the object is simply returned. - -.IP String -If the first argument is a string, -a command-line Action is returned. -Note that the command-line string -may be preceded by an -.B @ -(at-sign) -to suppress printing of the specified command line, -or by a -.B \- -(hyphen) -to ignore the exit status from the specified command: - -.ES -Action('$CC -c -o $TARGET $SOURCES') - -# Doesn't print the line being executed. -Action('@build $TARGET $SOURCES') - -# Ignores return value -Action('-build $TARGET $SOURCES') -.EE -.\" XXX From Gary Ruben, 23 April 2002: -.\" What would be useful is a discussion of how you execute command -.\" shell commands ie. what is the process used to spawn the shell, pass -.\" environment variables to it etc., whether there is one shell per -.\" environment or one per command etc. It might help to look at the Gnu -.\" make documentation to see what they think is important to discuss about -.\" a build system. I'm sure you can do a better job of organising the -.\" documentation than they have :-) - -.IP List -If the first argument is a list, -then a list of Action objects is returned. -An Action object is created as necessary -for each element in the list. -If an element -.I within -the list is itself a list, -the internal list is the -command and arguments to be executed via -the command line. -This allows white space to be enclosed -in an argument by defining -a command in a list within a list: - -.ES -Action([['cc', '-c', '-DWHITE SPACE', '-o', '$TARGET', '$SOURCES']]) -.EE - -.IP Function -If the first argument is a Python function, -a function Action is returned. -The Python function must take three keyword arguments, -.B target -(a Node object representing the target file), -.B source -(a Node object representing the source file) -and -.B env -(the construction environment -used for building the target file). -The -.B target -and -.B source -arguments may be lists of Node objects if there is -more than one target file or source file. -The actual target and source file name(s) may -be retrieved from their Node objects -via the built-in Python str() function: - -.ES -target_file_name = str(target) -source_file_names = map(lambda x: str(x), source) -.EE -.IP -The function should return -.B 0 -or -.B None -to indicate a successful build of the target file(s). -The function may raise an exception -or return a non-zero exit status -to indicate an unsuccessful build. - -.ES -def build_it(target = None, source = None, env = None): - # build the target from the source - return 0 - -a = Action(build_it) -.EE - -If the action argument is not one of the above, -None is returned. -.PP - -The second argument is optional and is used to define the output -which is printed when the Action is actually performed. -In the absence of this parameter, -or if it's an empty string, -a default output depending on the type of the action is used. -For example, a command-line action will print the executed command. -The argument must be either a Python function or a string. - -In the first case, -it's a function that returns a string to be printed -to describe the action being executed. -The function may also be specified by the -.IR strfunction = -keyword argument. -Like a function to build a file, -this function must take three keyword arguments: -.B target -(a Node object representing the target file), -.B source -(a Node object representing the source file) -and -.BR env -(a construction environment). -The -.B target -and -.B source -arguments may be lists of Node objects if there is -more than one target file or source file. - -In the second case, you provide the string itself. -The string may also be specified by the -.IR cmdstr = -keyword argument. -The string typically contains variables, notably -$TARGET(S) and $SOURCE(S), or consists of just a single -variable, which is optionally defined somewhere else. -SCons itself heavily uses the latter variant. - -Examples: - -.ES -def build_it(target, source, env): - # build the target from the source - return 0 - -def string_it(target, source, env): - return "building '%s' from '%s'" % (target[0], source[0]) - -# Use a positional argument. -f = Action(build_it, string_it) -s = Action(build_it, "building '$TARGET' from '$SOURCE'") - -# Alternatively, use a keyword argument. -f = Action(build_it, strfunction=string_it) -s = Action(build_it, cmdstr="building '$TARGET' from '$SOURCE'") - -# You can provide a configurable variable. -l = Action(build_it, '$STRINGIT') -.EE - -The third and succeeding arguments, if present, -may either be a construction variable or a list of construction variables -whose values will be included in the signature of the Action -when deciding whether a target should be rebuilt because the action changed. -The variables may also be specified by a -.IR varlist = -keyword parameter; -if both are present, they are combined. -This is necessary whenever you want a target to be rebuilt -when a specific construction variable changes. -This is not often needed for a string action, -as the expanded variables will normally be part of the command line, -but may be needed if a Python function action uses -the value of a construction variable when generating the command line. - -.ES -def build_it(target, source, env): - # build the target from the 'XXX' construction variable - open(target[0], 'w').write(env['XXX']) - return 0 - -# Use positional arguments. -a = Action(build_it, '$STRINGIT', ['XXX']) - -# Alternatively, use a keyword argument. -a = Action(build_it, varlist=['XXX']) -.EE - -The -.BR Action () -global function -can be passed the following -optional keyword arguments -to modify the Action object's behavior: - -.IP -.B chdir -The -.B chdir -keyword argument specifies that -scons will execute the action -after changing to the specified directory. -If the -.B chdir -argument is -a string or a directory Node, -scons will change to the specified directory. -If the -.B chdir -argument -is not a string or Node -and is non-zero, -then scons will change to the -target file's directory. - -Note that scons will -.I not -automatically modify -its expansion of -construction variables like -.B $TARGET -and -.B $SOURCE -when using the chdir -keyword argument--that is, -the expanded file names -will still be relative to -the top-level SConstruct directory, -and consequently incorrect -relative to the chdir directory. -Builders created using chdir keyword argument, -will need to use construction variable -expansions like -.B ${TARGET.file} -and -.B ${SOURCE.file} -to use just the filename portion of the -targets and source. - -.ES -a = Action("build < ${SOURCE.file} > ${TARGET.file}", - chdir=1) -.EE - -.IP -.B exitstatfunc -The -.BR Action () -global function -also takes an -.B exitstatfunc -keyword argument -which specifies a function -that is passed the exit status -(or return value) -from the specified action -and can return an arbitrary -or modified value. -This can be used, for example, -to specify that an Action object's -return value should be ignored -under special conditions -and SCons should, therefore, -consider that the action always suceeds: - -.ES -def always_succeed(s): - # Always return 0, which indicates success. - return 0 -a = Action("build < ${SOURCE.file} > ${TARGET.file}", - exitstatfunc=always_succeed) -.EE - -.IP -.B batch_key -The -.B batch_key -keyword argument can be used -to specify that the Action can create multiple target files -by processing multiple independent source files simultaneously. -(The canonical example is "batch compilation" -of multiple object files -by passing multiple source files -to a single invocation of a compiler -such as Microsoft's Visual C / C++ compiler.) -If the -.B batch_key -argument is any non-False, non-callable Python value, -the configured Action object will cause -.B scons -to collect all targets built with the Action object -and configured with the same construction environment -into single invocations of the Action object's -command line or function. -Command lines will typically want to use the -.BR CHANGED_SOURCES -construction variable -(and possibly -.BR CHANGED_TARGETS -as well) -to only pass to the command line those sources that -have actually changed since their targets were built. - -Example: - -.ES -a = Action('build $CHANGED_SOURCES', batch_key=True) -.EE - -The -.B batch_key -argument may also be -a callable function -that returns a key that -will be used to identify different -"batches" of target files to be collected -for batch building. -A -.B batch_key -function must take the following arguments: - -.IP action -The action object. - -.IP env -The construction environment -configured for the target. - -.IP target -The list of targets for a particular configured action. - -.IP source -The list of source for a particular configured action. - -The returned key should typically -be a tuple of values derived from the arguments, -using any appropriate logic to decide -how multiple invocations should be batched. -For example, a -.B batch_key -function may decide to return -the value of a specific construction -variable from the -.B env -argument -which will cause -.B scons -to batch-build targets -with matching values of that variable, -or perhaps return the -.BR id () -of the entire construction environment, -in which case -.B scons -will batch-build -all targets configured with the same construction environment. -Returning -.B None -indicates that -the particular target should -.I not -be part of any batched build, -but instead will be built -by a separate invocation of action's -command or function. -Example: - -.ES -def batch_key(action, env, target, source): - tdir = target[0].dir - if tdir.name == 'special': - # Don't batch-build any target - # in the special/ subdirectory. - return None - return (id(action), id(env), tdir) -a = Action('build $CHANGED_SOURCES', batch_key=batch_key) -.EE - -.SS Miscellaneous Action Functions - -.B scons -supplies a number of functions -that arrange for various common -file and directory manipulations -to be performed. -These are similar in concept to "tasks" in the -Ant build tool, -although the implementation is slightly different. -These functions do not actually -perform the specified action -at the time the function is called, -but instead return an Action object -that can be executed at the -appropriate time. -(In Object-Oriented terminology, -these are actually -Action -.I Factory -functions -that return Action objects.) - -In practice, -there are two natural ways -that these -Action Functions -are intended to be used. - -First, -if you need -to perform the action -at the time the SConscript -file is being read, -you can use the -.B Execute -global function to do so: -.ES -Execute(Touch('file')) -.EE - -Second, -you can use these functions -to supply Actions in a list -for use by the -.B Command -method. -This can allow you to -perform more complicated -sequences of file manipulation -without relying -on platform-specific -external commands: -that -.ES -env = Environment(TMPBUILD = '/tmp/builddir') -env.Command('foo.out', 'foo.in', - [Mkdir('$TMPBUILD'), - Copy('$TMPBUILD', '${SOURCE.dir}'), - "cd $TMPBUILD && make", - Delete('$TMPBUILD')]) -.EE - -.TP -.RI Chmod( dest ", " mode ) -Returns an Action object that -changes the permissions on the specified -.I dest -file or directory to the specified -.IR mode . -Examples: - -.ES -Execute(Chmod('file', 0755)) - -env.Command('foo.out', 'foo.in', - [Copy('$TARGET', '$SOURCE'), - Chmod('$TARGET', 0755)]) -.EE - -.TP -.RI Copy( dest ", " src ) -Returns an Action object -that will copy the -.I src -source file or directory to the -.I dest -destination file or directory. -Examples: - -.ES -Execute(Copy('foo.output', 'foo.input')) - -env.Command('bar.out', 'bar.in', - Copy('$TARGET', '$SOURCE')) -.EE - -.TP -.RI Delete( entry ", [" must_exist ]) -Returns an Action that -deletes the specified -.IR entry , -which may be a file or a directory tree. -If a directory is specified, -the entire directory tree -will be removed. -If the -.I must_exist -flag is set, -then a Python error will be thrown -if the specified entry does not exist; -the default is -.BR must_exist=0 , -that is, the Action will silently do nothing -if the entry does not exist. -Examples: - -.ES -Execute(Delete('/tmp/buildroot')) - -env.Command('foo.out', 'foo.in', - [Delete('${TARGET.dir}'), - MyBuildAction]) - -Execute(Delete('file_that_must_exist', must_exist=1)) -.EE - -.TP -.RI Mkdir( dir ) -Returns an Action -that creates the specified -directory -.I dir . -Examples: - -.ES -Execute(Mkdir('/tmp/outputdir')) - -env.Command('foo.out', 'foo.in', - [Mkdir('/tmp/builddir'), - Copy('/tmp/builddir/foo.in', '$SOURCE'), - "cd /tmp/builddir && make", - Copy('$TARGET', '/tmp/builddir/foo.out')]) -.EE - -.TP -.RI Move( dest ", " src ) -Returns an Action -that moves the specified -.I src -file or directory to -the specified -.I dest -file or directory. -Examples: - -.ES -Execute(Move('file.destination', 'file.source')) - -env.Command('output_file', 'input_file', - [MyBuildAction, - Move('$TARGET', 'file_created_by_MyBuildAction')]) -.EE - -.TP -.RI Touch( file ) -Returns an Action -that updates the modification time -on the specified -.IR file . -Examples: - -.ES -Execute(Touch('file_to_be_touched')) - -env.Command('marker', 'input_file', - [MyBuildAction, - Touch('$TARGET')]) -.EE - -.SS Variable Substitution - -Before executing a command, -.B scons -performs construction variable interpolation on the strings that make up -the command line of builders. -Variables are introduced by a -.B $ -prefix. -Besides construction variables, scons provides the following -variables for each command execution: - -.IP CHANGED_SOURCES -The file names of all sources of the build command -that have changed since the target was last built. - -.IP CHANGED_TARGETS -The file names of all targets that would be built -from sources that have changed since the target was last built. - -.IP SOURCE -The file name of the source of the build command, -or the file name of the first source -if multiple sources are being built. - -.IP SOURCES -The file names of the sources of the build command. - -.IP TARGET -The file name of the target being built, -or the file name of the first target -if multiple targets are being built. - -.IP TARGETS -The file names of all targets being built. - -.IP UNCHANGED_SOURCES -The file names of all sources of the build command -that have -.I not -changed since the target was last built. - -.IP UNCHANGED_TARGETS -The file names of all targets that would be built -from sources that have -.I not -changed since the target was last built. - -(Note that the above variables are reserved -and may not be set in a construction environment.) - -.LP -For example, given the construction variable CC='cc', targets=['foo'], and -sources=['foo.c', 'bar.c']: - -.ES -action='$CC -c -o $TARGET $SOURCES' -.EE - -would produce the command line: - -.ES -cc -c -o foo foo.c bar.c -.EE - -Variable names may be surrounded by curly braces ({}) -to separate the name from the trailing characters. -Within the curly braces, a variable name may have -a Python slice subscript appended to select one -or more items from a list. -In the previous example, the string: - -.ES -${SOURCES[1]} -.EE - -would produce: - -.ES -bar.c -.EE - -Additionally, a variable name may -have the following special -modifiers appended within the enclosing curly braces -to modify the interpolated string: - -.IP base -The base path of the file name, -including the directory path -but excluding any suffix. - -.IP dir -The name of the directory in which the file exists. - -.IP file -The file name, -minus any directory portion. - -.IP filebase -Just the basename of the file, -minus any suffix -and minus the directory. - -.IP suffix -Just the file suffix. - -.IP abspath -The absolute path name of the file. - -.IP posix -The POSIX form of the path, -with directories separated by -.B / -(forward slashes) -not backslashes. -This is sometimes necessary on Windows systems -when a path references a file on other (POSIX) systems. - -.IP srcpath -The directory and file name to the source file linked to this file through -.BR VariantDir (). -If this file isn't linked, -it just returns the directory and filename unchanged. - -.IP srcdir -The directory containing the source file linked to this file through -.BR VariantDir (). -If this file isn't linked, -it just returns the directory part of the filename. - -.IP rsrcpath -The directory and file name to the source file linked to this file through -.BR VariantDir (). -If the file does not exist locally but exists in a Repository, -the path in the Repository is returned. -If this file isn't linked, it just returns the -directory and filename unchanged. - -.IP rsrcdir -The Repository directory containing the source file linked to this file through -.BR VariantDir (). -If this file isn't linked, -it just returns the directory part of the filename. - -.LP -For example, the specified target will -expand as follows for the corresponding modifiers: - -.ES -$TARGET => sub/dir/file.x -${TARGET.base} => sub/dir/file -${TARGET.dir} => sub/dir -${TARGET.file} => file.x -${TARGET.filebase} => file -${TARGET.suffix} => .x -${TARGET.abspath} => /top/dir/sub/dir/file.x - -SConscript('src/SConscript', variant_dir='sub/dir') -$SOURCE => sub/dir/file.x -${SOURCE.srcpath} => src/file.x -${SOURCE.srcdir} => src - -Repository('/usr/repository') -$SOURCE => sub/dir/file.x -${SOURCE.rsrcpath} => /usr/repository/src/file.x -${SOURCE.rsrcdir} => /usr/repository/src -.EE - -Note that curly braces braces may also be used -to enclose arbitrary Python code to be evaluated. -(In fact, this is how the above modifiers are substituted, -they are simply attributes of the Python objects -that represent TARGET, SOURCES, etc.) -See the section "Python Code Substitution" below, -for more thorough examples of -how this can be used. - -Lastly, a variable name -may be a callable Python function -associated with a -construction variable in the environment. -The function should -take four arguments: -.I target -- a list of target nodes, -.I source -- a list of source nodes, -.I env -- the construction environment, -.I for_signature -- a Boolean value that specifies -whether the function is being called -for generating a build signature. -SCons will insert whatever -the called function returns -into the expanded string: - -.ES -def foo(target, source, env, for_signature): - return "bar" - -# Will expand $BAR to "bar baz" -env=Environment(FOO=foo, BAR="$FOO baz") -.EE - -You can use this feature to pass arguments to a -Python function by creating a callable class -that stores one or more arguments in an object, -and then uses them when the -.B __call__() -method is called. -Note that in this case, -the entire variable expansion must -be enclosed by curly braces -so that the arguments will -be associated with the -instantiation of the class: - -.ES -class foo(object): - def __init__(self, arg): - self.arg = arg - - def __call__(self, target, source, env, for_signature): - return self.arg + " bar" - -# Will expand $BAR to "my argument bar baz" -env=Environment(FOO=foo, BAR="${FOO('my argument')} baz") -.EE - -.LP -The special pseudo-variables -.B "$(" -and -.B "$)" -may be used to surround parts of a command line -that may change -.I without -causing a rebuild--that is, -which are not included in the signature -of target files built with this command. -All text between -.B "$(" -and -.B "$)" -will be removed from the command line -before it is added to file signatures, -and the -.B "$(" -and -.B "$)" -will be removed before the command is executed. -For example, the command line: - -.ES -echo Last build occurred $( $TODAY $). > $TARGET -.EE - -.LP -would execute the command: - -.ES -echo Last build occurred $TODAY. > $TARGET -.EE - -.LP -but the command signature added to any target files would be: - -.ES -echo Last build occurred . > $TARGET -.EE - -.SS Python Code Substitution - -Any python code within -.BR "${" - "}" -pairs gets evaluated by python 'eval', with the python globals set to -the current environment's set of construction variables. -So in the following case: -.ES -env['COND'] = 0 -env.Command('foo.out', 'foo.in', - '''echo ${COND==1 and 'FOO' or 'BAR'} > $TARGET''') -.EE -the command executed will be either -.ES -echo FOO > foo.out -.EE -or -.ES -echo BAR > foo.out -.EE -according to the current value of env['COND'] when the command is -executed. The evaluation occurs when the target is being -built, not when the SConscript is being read. So if env['COND'] is changed -later in the SConscript, the final value will be used. - -Here's a more interesting example. Note that all of COND, FOO, and -BAR are environment variables, and their values are substituted into -the final command. FOO is a list, so its elements are interpolated -separated by spaces. - -.ES -env=Environment() -env['COND'] = 0 -env['FOO'] = ['foo1', 'foo2'] -env['BAR'] = 'barbar' -env.Command('foo.out', 'foo.in', - 'echo ${COND==1 and FOO or BAR} > $TARGET') - -# Will execute this: -# echo foo1 foo2 > foo.out -.EE - -SCons uses the following rules when converting construction variables into -command lines: - -.IP String -When the value is a string it is interpreted as a space delimited list of -command line arguments. - -.IP List -When the value is a list it is interpreted as a list of command line -arguments. Each element of the list is converted to a string. - -.IP Other -Anything that is not a list or string is converted to a string and -interpreted as a single command line argument. - -.IP Newline -Newline characters (\\n) delimit lines. The newline parsing is done after -all other parsing, so it is not possible for arguments (e.g. file names) to -contain embedded newline characters. This limitation will likely go away in -a future version of SCons. - -.SS Scanner Objects - -You can use the -.B Scanner -function to define -objects to scan -new file types for implicit dependencies. -The -.B Scanner -function accepts the following arguments: - -.IP function -This can be either: -1) a Python function that will process -the Node (file) -and return a list of File Nodes -representing the implicit -dependencies (file names) found in the contents; -or: -2) a dictionary that maps keys -(typically the file suffix, but see below for more discussion) -to other Scanners that should be called. - -If the argument is actually a Python function, -the function must take three or four arguments: - - def scanner_function(node, env, path): - - def scanner_function(node, env, path, arg=None): - -The -.B node -argument is the internal -SCons node representing the file. -Use -.B str(node) -to fetch the name of the file, and -.B node.get_contents() -to fetch contents of the file. -Note that the file is -.I not -guaranteed to exist before the scanner is called, -so the scanner function should check that -if there's any chance that the scanned file -might not exist -(for example, if it's built from other files). - -The -.B env -argument is the construction environment for the scan. -Fetch values from it using the -.B env.Dictionary() -method. - -The -.B path -argument is a tuple (or list) -of directories that can be searched -for files. -This will usually be the tuple returned by the -.B path_function -argument (see below). - -The -.B arg -argument is the argument supplied -when the scanner was created, if any. - -.IP name -The name of the Scanner. -This is mainly used -to identify the Scanner internally. - -.IP argument -An optional argument that, if specified, -will be passed to the scanner function -(described above) -and the path function -(specified below). - -.IP skeys -An optional list that can be used to -determine which scanner should be used for -a given Node. -In the usual case of scanning for file names, -this argument will be a list of suffixes -for the different file types that this -Scanner knows how to scan. -If the argument is a string, -then it will be expanded -into a list by the current environment. - -.IP path_function -A Python function that takes four or five arguments: -a construction environment, -a Node for the directory containing -the SConscript file in which -the first target was defined, -a list of target nodes, -a list of source nodes, -and an optional argument supplied -when the scanner was created. -The -.B path_function -returns a tuple of directories -that can be searched for files to be returned -by this Scanner object. -(Note that the -.BR FindPathDirs () -function can be used to return a ready-made -.B path_function -for a given construction variable name, -instead of having to write your own function from scratch.) - -.IP node_class -The class of Node that should be returned -by this Scanner object. -Any strings or other objects returned -by the scanner function -that are not of this class -will be run through the -.B node_factory -function. - -.IP node_factory -A Python function that will take a string -or other object -and turn it into the appropriate class of Node -to be returned by this Scanner object. - -.IP scan_check -An optional Python function that takes two arguments, -a Node (file) and a construction environment, -and returns whether the -Node should, in fact, -be scanned for dependencies. -This check can be used to eliminate unnecessary -calls to the scanner function when, -for example, the underlying file -represented by a Node does not yet exist. - -.IP recursive -An optional flag that -specifies whether this scanner should be re-invoked -on the dependency files returned by the scanner. -When this flag is not set, -the Node subsystem will -only invoke the scanner on the file being scanned, -and not (for example) also on the files -specified by the #include lines -in the file being scanned. -.I recursive -may be a callable function, -in which case it will be called with a list of -Nodes found and -should return a list of Nodes -that should be scanned recursively; -this can be used to select a specific subset of -Nodes for additional scanning. - -.RE -Note that -.B scons -has a global -.B SourceFileScanner -object that is used by -the -.BR Object (), -.BR SharedObject (), -and -.BR StaticObject () -builders to decide -which scanner should be used -for different file extensions. -You can using the -.BR SourceFileScanner.add_scanner () -method to add your own Scanner object -to the -.B scons -infrastructure -that builds target programs or -libraries from a list of -source files of different types: - -.ES -def xyz_scan(node, env, path): - contents = node.get_text_contents() - # Scan the contents and return the included files. - -XYZScanner = Scanner(xyz_scan) - -SourceFileScanner.add_scanner('.xyz', XYZScanner) - -env.Program('my_prog', ['file1.c', 'file2.f', 'file3.xyz']) -.EE - -.SH SYSTEM-SPECIFIC BEHAVIOR -SCons and its configuration files are very portable, -due largely to its implementation in Python. -There are, however, a few portability -issues waiting to trap the unwary. -.SS .C file suffix -SCons handles the upper-case -.B .C -file suffix differently, -depending on the capabilities of -the underlying system. -On a case-sensitive system -such as Linux or UNIX, -SCons treats a file with a -.B .C -suffix as a C++ source file. -On a case-insensitive system -such as Windows, -SCons treats a file with a -.B .C -suffix as a C source file. -.SS .F file suffix -SCons handles the upper-case -.B .F -file suffix differently, -depending on the capabilities of -the underlying system. -On a case-sensitive system -such as Linux or UNIX, -SCons treats a file with a -.B .F -suffix as a Fortran source file -that is to be first run through -the standard C preprocessor. -On a case-insensitive system -such as Windows, -SCons treats a file with a -.B .F -suffix as a Fortran source file that should -.I not -be run through the C preprocessor. -.SS Windows: Cygwin Tools and Cygwin Python vs. Windows Pythons -Cygwin supplies a set of tools and utilities -that let users work on a -Windows system using a more POSIX-like environment. -The Cygwin tools, including Cygwin Python, -do this, in part, -by sharing an ability to interpret UNIX-like path names. -For example, the Cygwin tools -will internally translate a Cygwin path name -like /cygdrive/c/mydir -to an equivalent Windows pathname -of C:/mydir (equivalent to C:\\mydir). - -Versions of Python -that are built for native Windows execution, -such as the python.org and ActiveState versions, -do not have the Cygwin path name semantics. -This means that using a native Windows version of Python -to build compiled programs using Cygwin tools -(such as gcc, bison, and flex) -may yield unpredictable results. -"Mixing and matching" in this way -can be made to work, -but it requires careful attention to the use of path names -in your SConscript files. - -In practice, users can sidestep -the issue by adopting the following rules: -When using gcc, -use the Cygwin-supplied Python interpreter -to run SCons; -when using Microsoft Visual C/C++ -(or some other Windows compiler) -use the python.org or ActiveState version of Python -to run SCons. -.SS Windows: scons.bat file -On Windows systems, -SCons is executed via a wrapper -.B scons.bat -file. -This has (at least) two ramifications: - -First, Windows command-line users -that want to use variable assignment -on the command line -may have to put double quotes -around the assignments: - -.ES -scons "FOO=BAR" "BAZ=BLEH" -.EE - -Second, the Cygwin shell does not -recognize this file as being the same -as an -.B scons -command issued at the command-line prompt. -You can work around this either by -executing -.B scons.bat -from the Cygwin command line, -or by creating a wrapper shell -script named -.B scons . - -.SS MinGW - -The MinGW bin directory must be in your PATH environment variable or the -PATH variable under the ENV construction variable for SCons -to detect and use the MinGW tools. When running under the native Windows -Python interpreter, SCons will prefer the MinGW tools over the Cygwin -tools, if they are both installed, regardless of the order of the bin -directories in the PATH variable. If you have both MSVC and MinGW -installed and you want to use MinGW instead of MSVC, -then you must explictly tell SCons to use MinGW by passing - -.ES -tools=['mingw'] -.EE - -to the Environment() function, because SCons will prefer the MSVC tools -over the MinGW tools. - -.SH EXAMPLES - -To help you get started using SCons, -this section contains a brief overview of some common tasks. - -.SS Basic Compilation From a Single Source File - -.ES -env = Environment() -env.Program(target = 'foo', source = 'foo.c') -.EE - -Note: Build the file by specifying -the target as an argument -("scons foo" or "scons foo.exe"). -or by specifying a dot ("scons ."). - -.SS Basic Compilation From Multiple Source Files - -.ES -env = Environment() -env.Program(target = 'foo', source = Split('f1.c f2.c f3.c')) -.EE - -.SS Setting a Compilation Flag - -.ES -env = Environment(CCFLAGS = '-g') -env.Program(target = 'foo', source = 'foo.c') -.EE - -.SS Search The Local Directory For .h Files - -Note: You do -.I not -need to set CCFLAGS to specify -I options by hand. -SCons will construct the right -I options from CPPPATH. - -.ES -env = Environment(CPPPATH = ['.']) -env.Program(target = 'foo', source = 'foo.c') -.EE - -.SS Search Multiple Directories For .h Files - -.ES -env = Environment(CPPPATH = ['include1', 'include2']) -env.Program(target = 'foo', source = 'foo.c') -.EE - -.SS Building a Static Library - -.ES -env = Environment() -env.StaticLibrary(target = 'foo', source = Split('l1.c l2.c')) -env.StaticLibrary(target = 'bar', source = ['l3.c', 'l4.c']) -.EE - -.SS Building a Shared Library - -.ES -env = Environment() -env.SharedLibrary(target = 'foo', source = ['l5.c', 'l6.c']) -env.SharedLibrary(target = 'bar', source = Split('l7.c l8.c')) -.EE - -.SS Linking a Local Library Into a Program - -.ES -env = Environment(LIBS = 'mylib', LIBPATH = ['.']) -env.Library(target = 'mylib', source = Split('l1.c l2.c')) -env.Program(target = 'prog', source = ['p1.c', 'p2.c']) -.EE - -.SS Defining Your Own Builder Object - -Notice that when you invoke the Builder, -you can leave off the target file suffix, -and SCons will add it automatically. - -.ES -bld = Builder(action = 'pdftex < $SOURCES > $TARGET' - suffix = '.pdf', - src_suffix = '.tex') -env = Environment(BUILDERS = {'PDFBuilder' : bld}) -env.PDFBuilder(target = 'foo.pdf', source = 'foo.tex') - -# The following creates "bar.pdf" from "bar.tex" -env.PDFBuilder(target = 'bar', source = 'bar') -.EE - -Note also that the above initialization -overwrites the default Builder objects, -so the Environment created above -can not be used call Builders like env.Program(), -env.Object(), env.StaticLibrary(), etc. - -.SS Adding Your Own Builder Object to an Environment - -.ES -bld = Builder(action = 'pdftex < $SOURCES > $TARGET' - suffix = '.pdf', - src_suffix = '.tex') -env = Environment() -env.Append(BUILDERS = {'PDFBuilder' : bld}) -env.PDFBuilder(target = 'foo.pdf', source = 'foo.tex') -env.Program(target = 'bar', source = 'bar.c') -.EE - -You also can use other Pythonic techniques to add -to the BUILDERS construction variable, such as: - -.ES -env = Environment() -env['BUILDERS]['PDFBuilder'] = bld -.EE - -.SS Defining Your Own Scanner Object - -The following example shows an extremely simple scanner (the -.BR kfile_scan () -function) -that doesn't use a search path at all -and simply returns the -file names present on any -.B include -lines in the scanned file. -This would implicitly assume that all included -files live in the top-level directory: - -.ES -import re - -'\" Note: the \\ in the following are for the benefit of nroff/troff, -'\" not inappropriate doubled escape characters within the r'' raw string. -include_re = re.compile(r'^include\\s+(\\S+)$', re.M) - -def kfile_scan(node, env, path, arg): - contents = node.get_text_contents() - includes = include_re.findall(contents) - return env.File(includes) - -kscan = Scanner(name = 'kfile', - function = kfile_scan, - argument = None, - skeys = ['.k']) -scanners = Environment().Dictionary('SCANNERS') -env = Environment(SCANNERS = scanners + [kscan]) - -env.Command('foo', 'foo.k', 'kprocess < $SOURCES > $TARGET') - -bar_in = File('bar.in') -env.Command('bar', bar_in, 'kprocess $SOURCES > $TARGET') -bar_in.target_scanner = kscan -.EE - -It is important to note that you -have to return a list of File nodes from the scan function, simple -strings for the file names won't do. As in the examples we are showing here, -you can use the -.BR File() -function of your current Environment in order to create nodes on the fly from -a sequence of file names with relative paths. - -Here is a similar but more complete example that searches -a path of directories -(specified as the -.B MYPATH -construction variable) -for files that actually exist: - -.ES -import re -import os -include_re = re.compile(r'^include\\s+(\\S+)$', re.M) - -def my_scan(node, env, path, arg): - contents = node.get_text_contents() - includes = include_re.findall(contents) - if includes == []: - return [] - results = [] - for inc in includes: - for dir in path: - file = str(dir) + os.sep + inc - if os.path.exists(file): - results.append(file) - break - return env.File(results) - -scanner = Scanner(name = 'myscanner', - function = my_scan, - argument = None, - skeys = ['.x'], - path_function = FindPathDirs('MYPATH') - ) -scanners = Environment().Dictionary('SCANNERS') -env = Environment(SCANNERS = scanners + [scanner], - MYPATH = ['incs']) - -env.Command('foo', 'foo.x', 'xprocess < $SOURCES > $TARGET') -.EE - -The -.BR FindPathDirs () -function used in the previous example returns a function -(actually a callable Python object) -that will return a list of directories -specified in the -.B $MYPATH -construction variable. It lets SCons detect the file -.B incs/foo.inc -, even if -.B foo.x -contains the line -.B include foo.inc -only. -If you need to customize how the search path is derived, -you would provide your own -.B path_function -argument when creating the Scanner object, -as follows: - -.ES -# MYPATH is a list of directories to search for files in -def pf(env, dir, target, source, arg): - top_dir = Dir('#').abspath - results = [] - if 'MYPATH' in env: - for p in env['MYPATH']: - results.append(top_dir + os.sep + p) - return results - -scanner = Scanner(name = 'myscanner', - function = my_scan, - argument = None, - skeys = ['.x'], - path_function = pf - ) -.EE - -.SS Creating a Hierarchical Build - -Notice that the file names specified in a subdirectory's -SConscript -file are relative to that subdirectory. - -.ES -SConstruct: - - env = Environment() - env.Program(target = 'foo', source = 'foo.c') - - SConscript('sub/SConscript') - -sub/SConscript: - - env = Environment() - # Builds sub/foo from sub/foo.c - env.Program(target = 'foo', source = 'foo.c') - - SConscript('dir/SConscript') - -sub/dir/SConscript: - - env = Environment() - # Builds sub/dir/foo from sub/dir/foo.c - env.Program(target = 'foo', source = 'foo.c') -.EE - -.SS Sharing Variables Between SConscript Files - -You must explicitly Export() and Import() variables that -you want to share between SConscript files. - -.ES -SConstruct: - - env = Environment() - env.Program(target = 'foo', source = 'foo.c') - - Export("env") - SConscript('subdirectory/SConscript') - -subdirectory/SConscript: - - Import("env") - env.Program(target = 'foo', source = 'foo.c') -.EE - -.SS Building Multiple Variants From the Same Source - -Use the variant_dir keyword argument to -the SConscript function to establish -one or more separate variant build directory trees -for a given source directory: - -.ES -SConstruct: - - cppdefines = ['FOO'] - Export("cppdefines") - SConscript('src/SConscript', variant_dir='foo') - - cppdefines = ['BAR'] - Export("cppdefines") - SConscript('src/SConscript', variant_dir='bar') - -src/SConscript: - - Import("cppdefines") - env = Environment(CPPDEFINES = cppdefines) - env.Program(target = 'src', source = 'src.c') -.EE - -Note the use of the Export() method -to set the "cppdefines" variable to a different -value each time we call the SConscript function. - -.SS Hierarchical Build of Two Libraries Linked With a Program - -.ES -SConstruct: - - env = Environment(LIBPATH = ['#libA', '#libB']) - Export('env') - SConscript('libA/SConscript') - SConscript('libB/SConscript') - SConscript('Main/SConscript') - -libA/SConscript: - - Import('env') - env.Library('a', Split('a1.c a2.c a3.c')) - -libB/SConscript: - - Import('env') - env.Library('b', Split('b1.c b2.c b3.c')) - -Main/SConscript: - - Import('env') - e = env.Copy(LIBS = ['a', 'b']) - e.Program('foo', Split('m1.c m2.c m3.c')) -.EE - -The '#' in the LIBPATH directories specify that they're relative to the -top-level directory, so they don't turn into "Main/libA" when they're -used in Main/SConscript. - -Specifying only 'a' and 'b' for the library names -allows SCons to append the appropriate library -prefix and suffix for the current platform -(for example, 'liba.a' on POSIX systems, -\&'a.lib' on Windows). - -.SS Customizing construction variables from the command line. - -The following would allow the C compiler to be specified on the command -line or in the file custom.py. - -.ES -vars = Variables('custom.py') -vars.Add('CC', 'The C compiler.') -env = Environment(variables=vars) -Help(vars.GenerateHelpText(env)) -.EE - -The user could specify the C compiler on the command line: - -.ES -scons "CC=my_cc" -.EE - -or in the custom.py file: - -.ES -CC = 'my_cc' -.EE - -or get documentation on the options: - -.ES -$ scons -h - -CC: The C compiler. - default: None - actual: cc - -.EE - -.SS Using Microsoft Visual C++ precompiled headers - -Since windows.h includes everything and the kitchen sink, it can take quite -some time to compile it over and over again for a bunch of object files, so -Microsoft provides a mechanism to compile a set of headers once and then -include the previously compiled headers in any object file. This -technology is called precompiled headers. The general recipe is to create a -file named "StdAfx.cpp" that includes a single header named "StdAfx.h", and -then include every header you want to precompile in "StdAfx.h", and finally -include "StdAfx.h" as the first header in all the source files you are -compiling to object files. For example: - -StdAfx.h: -.ES -#include <windows.h> -#include <my_big_header.h> -.EE - -StdAfx.cpp: -.ES -#include <StdAfx.h> -.EE - -Foo.cpp: -.ES -#include <StdAfx.h> - -/* do some stuff */ -.EE - -Bar.cpp: -.ES -#include <StdAfx.h> - -/* do some other stuff */ -.EE - -SConstruct: -.ES -env=Environment() -env['PCHSTOP'] = 'StdAfx.h' -env['PCH'] = env.PCH('StdAfx.cpp')[0] -env.Program('MyApp', ['Foo.cpp', 'Bar.cpp']) -.EE - -For more information see the document for the PCH builder, and the PCH and -PCHSTOP construction variables. To learn about the details of precompiled -headers consult the MSDN documention for /Yc, /Yu, and /Yp. - -.SS Using Microsoft Visual C++ external debugging information - -Since including debugging information in programs and shared libraries can -cause their size to increase significantly, Microsoft provides a mechanism -for including the debugging information in an external file called a PDB -file. SCons supports PDB files through the PDB construction -variable. - -SConstruct: -.ES -env=Environment() -env['PDB'] = 'MyApp.pdb' -env.Program('MyApp', ['Foo.cpp', 'Bar.cpp']) -.EE - -For more information see the document for the PDB construction variable. - -.SH ENVIRONMENT - -.IP SCONS_LIB_DIR -Specifies the directory that contains the SCons Python module directory -(e.g. /home/aroach/scons-src-0.01/src/engine). - -.IP SCONSFLAGS -A string of options that will be used by scons in addition to those passed -on the command line. - -.SH "SEE ALSO" -.B scons -User Manual, -.B scons -Design Document, -.B scons -source code. - -.SH AUTHORS -Steven Knight <knight@baldmt.com> -.br -Anthony Roach <aroach@electriceyeball.com> - |