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Diffstat (limited to 'engine/SCons/Subst.py')
| -rw-r--r-- | engine/SCons/Subst.py | 912 |
1 files changed, 912 insertions, 0 deletions
diff --git a/engine/SCons/Subst.py b/engine/SCons/Subst.py new file mode 100644 index 0000000..0393dba --- /dev/null +++ b/engine/SCons/Subst.py @@ -0,0 +1,912 @@ +"""SCons.Subst + +SCons string substitution. + +""" + +# +# Copyright (c) 2001 - 2014 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. + +__revision__ = "src/engine/SCons/Subst.py 2014/09/27 12:51:43 garyo" + +import collections +import re + +import SCons.Errors + +from SCons.Util import is_String, is_Sequence + +# Indexed by the SUBST_* constants below. +_strconv = [SCons.Util.to_String_for_subst, + SCons.Util.to_String_for_subst, + SCons.Util.to_String_for_signature] + + + +AllowableExceptions = (IndexError, NameError) + +def SetAllowableExceptions(*excepts): + global AllowableExceptions + AllowableExceptions = [_f for _f in excepts if _f] + +def raise_exception(exception, target, s): + name = exception.__class__.__name__ + msg = "%s `%s' trying to evaluate `%s'" % (name, exception, s) + if target: + raise SCons.Errors.BuildError(target[0], msg) + else: + raise SCons.Errors.UserError(msg) + + + +class Literal(object): + """A wrapper for a string. If you use this object wrapped + around a string, then it will be interpreted as literal. + When passed to the command interpreter, all special + characters will be escaped.""" + def __init__(self, lstr): + self.lstr = lstr + + def __str__(self): + return self.lstr + + def escape(self, escape_func): + return escape_func(self.lstr) + + def for_signature(self): + return self.lstr + + def is_literal(self): + return 1 + + def __eq__(self, other): + if not isinstance(other, Literal): + return False + return self.lstr == other.lstr + + def __neq__(self, other): + return not self.__eq__(other) + +class SpecialAttrWrapper(object): + """This is a wrapper for what we call a 'Node special attribute.' + This is any of the attributes of a Node that we can reference from + Environment variable substitution, such as $TARGET.abspath or + $SOURCES[1].filebase. We implement the same methods as Literal + so we can handle special characters, plus a for_signature method, + such that we can return some canonical string during signature + calculation to avoid unnecessary rebuilds.""" + + def __init__(self, lstr, for_signature=None): + """The for_signature parameter, if supplied, will be the + canonical string we return from for_signature(). Else + we will simply return lstr.""" + self.lstr = lstr + if for_signature: + self.forsig = for_signature + else: + self.forsig = lstr + + def __str__(self): + return self.lstr + + def escape(self, escape_func): + return escape_func(self.lstr) + + def for_signature(self): + return self.forsig + + def is_literal(self): + return 1 + +def quote_spaces(arg): + """Generic function for putting double quotes around any string that + has white space in it.""" + if ' ' in arg or '\t' in arg: + return '"%s"' % arg + else: + return str(arg) + +class CmdStringHolder(collections.UserString): + """This is a special class used to hold strings generated by + scons_subst() and scons_subst_list(). It defines a special method + escape(). When passed a function with an escape algorithm for a + particular platform, it will return the contained string with the + proper escape sequences inserted. + """ + def __init__(self, cmd, literal=None): + collections.UserString.__init__(self, cmd) + self.literal = literal + + def is_literal(self): + return self.literal + + def escape(self, escape_func, quote_func=quote_spaces): + """Escape the string with the supplied function. The + function is expected to take an arbitrary string, then + return it with all special characters escaped and ready + for passing to the command interpreter. + + After calling this function, the next call to str() will + return the escaped string. + """ + + if self.is_literal(): + return escape_func(self.data) + elif ' ' in self.data or '\t' in self.data: + return quote_func(self.data) + else: + return self.data + +def escape_list(mylist, escape_func): + """Escape a list of arguments by running the specified escape_func + on every object in the list that has an escape() method.""" + def escape(obj, escape_func=escape_func): + try: + e = obj.escape + except AttributeError: + return obj + else: + return e(escape_func) + return list(map(escape, mylist)) + +class NLWrapper(object): + """A wrapper class that delays turning a list of sources or targets + into a NodeList until it's needed. The specified function supplied + when the object is initialized is responsible for turning raw nodes + into proxies that implement the special attributes like .abspath, + .source, etc. This way, we avoid creating those proxies just + "in case" someone is going to use $TARGET or the like, and only + go through the trouble if we really have to. + + In practice, this might be a wash performance-wise, but it's a little + cleaner conceptually... + """ + + def __init__(self, list, func): + self.list = list + self.func = func + def _return_nodelist(self): + return self.nodelist + def _gen_nodelist(self): + mylist = self.list + if mylist is None: + mylist = [] + elif not is_Sequence(mylist): + mylist = [mylist] + # The map(self.func) call is what actually turns + # a list into appropriate proxies. + self.nodelist = SCons.Util.NodeList(list(map(self.func, mylist))) + self._create_nodelist = self._return_nodelist + return self.nodelist + _create_nodelist = _gen_nodelist + + +class Targets_or_Sources(collections.UserList): + """A class that implements $TARGETS or $SOURCES expansions by in turn + wrapping a NLWrapper. This class handles the different methods used + to access the list, calling the NLWrapper to create proxies on demand. + + Note that we subclass collections.UserList purely so that the + is_Sequence() function will identify an object of this class as + a list during variable expansion. We're not really using any + collections.UserList methods in practice. + """ + def __init__(self, nl): + self.nl = nl + def __getattr__(self, attr): + nl = self.nl._create_nodelist() + return getattr(nl, attr) + def __getitem__(self, i): + nl = self.nl._create_nodelist() + return nl[i] + def __getslice__(self, i, j): + nl = self.nl._create_nodelist() + i = max(i, 0); j = max(j, 0) + return nl[i:j] + def __str__(self): + nl = self.nl._create_nodelist() + return str(nl) + def __repr__(self): + nl = self.nl._create_nodelist() + return repr(nl) + +class Target_or_Source(object): + """A class that implements $TARGET or $SOURCE expansions by in turn + wrapping a NLWrapper. This class handles the different methods used + to access an individual proxy Node, calling the NLWrapper to create + a proxy on demand. + """ + def __init__(self, nl): + self.nl = nl + def __getattr__(self, attr): + nl = self.nl._create_nodelist() + try: + nl0 = nl[0] + except IndexError: + # If there is nothing in the list, then we have no attributes to + # pass through, so raise AttributeError for everything. + raise AttributeError("NodeList has no attribute: %s" % attr) + return getattr(nl0, attr) + def __str__(self): + nl = self.nl._create_nodelist() + if nl: + return str(nl[0]) + return '' + def __repr__(self): + nl = self.nl._create_nodelist() + if nl: + return repr(nl[0]) + return '' + +class NullNodeList(SCons.Util.NullSeq): + def __call__(self, *args, **kwargs): return '' + def __str__(self): return '' + +NullNodesList = NullNodeList() + +def subst_dict(target, source): + """Create a dictionary for substitution of special + construction variables. + + This translates the following special arguments: + + target - the target (object or array of objects), + used to generate the TARGET and TARGETS + construction variables + + source - the source (object or array of objects), + used to generate the SOURCES and SOURCE + construction variables + """ + dict = {} + + if target: + def get_tgt_subst_proxy(thing): + try: + subst_proxy = thing.get_subst_proxy() + except AttributeError: + subst_proxy = thing # probably a string, just return it + return subst_proxy + tnl = NLWrapper(target, get_tgt_subst_proxy) + dict['TARGETS'] = Targets_or_Sources(tnl) + dict['TARGET'] = Target_or_Source(tnl) + + # This is a total cheat, but hopefully this dictionary goes + # away soon anyway. We just let these expand to $TARGETS + # because that's "good enough" for the use of ToolSurrogates + # (see test/ToolSurrogate.py) to generate documentation. + dict['CHANGED_TARGETS'] = '$TARGETS' + dict['UNCHANGED_TARGETS'] = '$TARGETS' + else: + dict['TARGETS'] = NullNodesList + dict['TARGET'] = NullNodesList + + if source: + def get_src_subst_proxy(node): + try: + rfile = node.rfile + except AttributeError: + pass + else: + node = rfile() + try: + return node.get_subst_proxy() + except AttributeError: + return node # probably a String, just return it + snl = NLWrapper(source, get_src_subst_proxy) + dict['SOURCES'] = Targets_or_Sources(snl) + dict['SOURCE'] = Target_or_Source(snl) + + # This is a total cheat, but hopefully this dictionary goes + # away soon anyway. We just let these expand to $TARGETS + # because that's "good enough" for the use of ToolSurrogates + # (see test/ToolSurrogate.py) to generate documentation. + dict['CHANGED_SOURCES'] = '$SOURCES' + dict['UNCHANGED_SOURCES'] = '$SOURCES' + else: + dict['SOURCES'] = NullNodesList + dict['SOURCE'] = NullNodesList + + return dict + +# Constants for the "mode" parameter to scons_subst_list() and +# scons_subst(). SUBST_RAW gives the raw command line. SUBST_CMD +# gives a command line suitable for passing to a shell. SUBST_SIG +# gives a command line appropriate for calculating the signature +# of a command line...if this changes, we should rebuild. +SUBST_CMD = 0 +SUBST_RAW = 1 +SUBST_SIG = 2 + +_rm = re.compile(r'\$[()]') +_remove = re.compile(r'\$\([^\$]*(\$[^\)][^\$]*)*\$\)') + +# Indexed by the SUBST_* constants above. +_regex_remove = [ _rm, None, _remove ] + +def _rm_list(list): + #return [ l for l in list if not l in ('$(', '$)') ] + return [l for l in list if not l in ('$(', '$)')] + +def _remove_list(list): + result = [] + do_append = result.append + for l in list: + if l == '$(': + do_append = lambda x: None + elif l == '$)': + do_append = result.append + else: + do_append(l) + return result + +# Indexed by the SUBST_* constants above. +_list_remove = [ _rm_list, None, _remove_list ] + +# Regular expressions for splitting strings and handling substitutions, +# for use by the scons_subst() and scons_subst_list() functions: +# +# The first expression compiled matches all of the $-introduced tokens +# that we need to process in some way, and is used for substitutions. +# The expressions it matches are: +# +# "$$" +# "$(" +# "$)" +# "$variable" [must begin with alphabetic or underscore] +# "${any stuff}" +# +# The second expression compiled is used for splitting strings into tokens +# to be processed, and it matches all of the tokens listed above, plus +# the following that affect how arguments do or don't get joined together: +# +# " " [white space] +# "non-white-space" [without any dollar signs] +# "$" [single dollar sign] +# +_dollar_exps_str = r'\$[\$\(\)]|\$[_a-zA-Z][\.\w]*|\${[^}]*}' +_dollar_exps = re.compile(r'(%s)' % _dollar_exps_str) +_separate_args = re.compile(r'(%s|\s+|[^\s\$]+|\$)' % _dollar_exps_str) + +# This regular expression is used to replace strings of multiple white +# space characters in the string result from the scons_subst() function. +_space_sep = re.compile(r'[\t ]+(?![^{]*})') + +def scons_subst(strSubst, env, mode=SUBST_RAW, target=None, source=None, gvars={}, lvars={}, conv=None): + """Expand a string or list containing construction variable + substitutions. + + This is the work-horse function for substitutions in file names + and the like. The companion scons_subst_list() function (below) + handles separating command lines into lists of arguments, so see + that function if that's what you're looking for. + """ + if isinstance(strSubst, str) and strSubst.find('$') < 0: + return strSubst + + class StringSubber(object): + """A class to construct the results of a scons_subst() call. + + This binds a specific construction environment, mode, target and + source with two methods (substitute() and expand()) that handle + the expansion. + """ + def __init__(self, env, mode, conv, gvars): + self.env = env + self.mode = mode + self.conv = conv + self.gvars = gvars + + def expand(self, s, lvars): + """Expand a single "token" as necessary, returning an + appropriate string containing the expansion. + + This handles expanding different types of things (strings, + lists, callables) appropriately. It calls the wrapper + substitute() method to re-expand things as necessary, so that + the results of expansions of side-by-side strings still get + re-evaluated separately, not smushed together. + """ + if is_String(s): + try: + s0, s1 = s[:2] + except (IndexError, ValueError): + return s + if s0 != '$': + return s + if s1 == '$': + return '$' + elif s1 in '()': + return s + else: + key = s[1:] + if key[0] == '{' or key.find('.') >= 0: + if key[0] == '{': + key = key[1:-1] + try: + s = eval(key, self.gvars, lvars) + except KeyboardInterrupt: + raise + except Exception, e: + if e.__class__ in AllowableExceptions: + return '' + raise_exception(e, lvars['TARGETS'], s) + else: + if key in lvars: + s = lvars[key] + elif key in self.gvars: + s = self.gvars[key] + elif not NameError in AllowableExceptions: + raise_exception(NameError(key), lvars['TARGETS'], s) + else: + return '' + + # Before re-expanding the result, handle + # recursive expansion by copying the local + # variable dictionary and overwriting a null + # string for the value of the variable name + # we just expanded. + # + # This could potentially be optimized by only + # copying lvars when s contains more expansions, + # but lvars is usually supposed to be pretty + # small, and deeply nested variable expansions + # are probably more the exception than the norm, + # so it should be tolerable for now. + lv = lvars.copy() + var = key.split('.')[0] + lv[var] = '' + return self.substitute(s, lv) + elif is_Sequence(s): + def func(l, conv=self.conv, substitute=self.substitute, lvars=lvars): + return conv(substitute(l, lvars)) + return list(map(func, s)) + elif callable(s): + try: + s = s(target=lvars['TARGETS'], + source=lvars['SOURCES'], + env=self.env, + for_signature=(self.mode != SUBST_CMD)) + except TypeError: + # This probably indicates that it's a callable + # object that doesn't match our calling arguments + # (like an Action). + if self.mode == SUBST_RAW: + return s + s = self.conv(s) + return self.substitute(s, lvars) + elif s is None: + return '' + else: + return s + + def substitute(self, args, lvars): + """Substitute expansions in an argument or list of arguments. + + This serves as a wrapper for splitting up a string into + separate tokens. + """ + if is_String(args) and not isinstance(args, CmdStringHolder): + args = str(args) # In case it's a UserString. + try: + def sub_match(match): + return self.conv(self.expand(match.group(1), lvars)) + result = _dollar_exps.sub(sub_match, args) + except TypeError: + # If the internal conversion routine doesn't return + # strings (it could be overridden to return Nodes, for + # example), then the 1.5.2 re module will throw this + # exception. Back off to a slower, general-purpose + # algorithm that works for all data types. + args = _separate_args.findall(args) + result = [] + for a in args: + result.append(self.conv(self.expand(a, lvars))) + if len(result) == 1: + result = result[0] + else: + result = ''.join(map(str, result)) + return result + else: + return self.expand(args, lvars) + + if conv is None: + conv = _strconv[mode] + + # Doing this every time is a bit of a waste, since the Executor + # has typically already populated the OverrideEnvironment with + # $TARGET/$SOURCE variables. We're keeping this (for now), though, + # because it supports existing behavior that allows us to call + # an Action directly with an arbitrary target+source pair, which + # we use in Tool/tex.py to handle calling $BIBTEX when necessary. + # If we dropped that behavior (or found another way to cover it), + # we could get rid of this call completely and just rely on the + # Executor setting the variables. + if 'TARGET' not in lvars: + d = subst_dict(target, source) + if d: + lvars = lvars.copy() + lvars.update(d) + + # We're (most likely) going to eval() things. If Python doesn't + # find a __builtins__ value in the global dictionary used for eval(), + # it copies the current global values for you. Avoid this by + # setting it explicitly and then deleting, so we don't pollute the + # construction environment Dictionary(ies) that are typically used + # for expansion. + gvars['__builtins__'] = __builtins__ + + ss = StringSubber(env, mode, conv, gvars) + result = ss.substitute(strSubst, lvars) + + try: + del gvars['__builtins__'] + except KeyError: + pass + + if is_String(result): + # Remove $(-$) pairs and any stuff in between, + # if that's appropriate. + remove = _regex_remove[mode] + if remove: + result = remove.sub('', result) + if mode != SUBST_RAW: + # Compress strings of white space characters into + # a single space. + result = _space_sep.sub(' ', result).strip() + elif is_Sequence(result): + remove = _list_remove[mode] + if remove: + result = remove(result) + + return result + +#Subst_List_Strings = {} + +def scons_subst_list(strSubst, env, mode=SUBST_RAW, target=None, source=None, gvars={}, lvars={}, conv=None): + """Substitute construction variables in a string (or list or other + object) and separate the arguments into a command list. + + The companion scons_subst() function (above) handles basic + substitutions within strings, so see that function instead + if that's what you're looking for. + """ +# try: +# Subst_List_Strings[strSubst] = Subst_List_Strings[strSubst] + 1 +# except KeyError: +# Subst_List_Strings[strSubst] = 1 +# import SCons.Debug +# SCons.Debug.caller_trace(1) + class ListSubber(collections.UserList): + """A class to construct the results of a scons_subst_list() call. + + Like StringSubber, this class binds a specific construction + environment, mode, target and source with two methods + (substitute() and expand()) that handle the expansion. + + In addition, however, this class is used to track the state of + the result(s) we're gathering so we can do the appropriate thing + whenever we have to append another word to the result--start a new + line, start a new word, append to the current word, etc. We do + this by setting the "append" attribute to the right method so + that our wrapper methods only need ever call ListSubber.append(), + and the rest of the object takes care of doing the right thing + internally. + """ + def __init__(self, env, mode, conv, gvars): + collections.UserList.__init__(self, []) + self.env = env + self.mode = mode + self.conv = conv + self.gvars = gvars + + if self.mode == SUBST_RAW: + self.add_strip = lambda x: self.append(x) + else: + self.add_strip = lambda x: None + self.in_strip = None + self.next_line() + + def expand(self, s, lvars, within_list): + """Expand a single "token" as necessary, appending the + expansion to the current result. + + This handles expanding different types of things (strings, + lists, callables) appropriately. It calls the wrapper + substitute() method to re-expand things as necessary, so that + the results of expansions of side-by-side strings still get + re-evaluated separately, not smushed together. + """ + + if is_String(s): + try: + s0, s1 = s[:2] + except (IndexError, ValueError): + self.append(s) + return + if s0 != '$': + self.append(s) + return + if s1 == '$': + self.append('$') + elif s1 == '(': + self.open_strip('$(') + elif s1 == ')': + self.close_strip('$)') + else: + key = s[1:] + if key[0] == '{' or key.find('.') >= 0: + if key[0] == '{': + key = key[1:-1] + try: + s = eval(key, self.gvars, lvars) + except KeyboardInterrupt: + raise + except Exception, e: + if e.__class__ in AllowableExceptions: + return + raise_exception(e, lvars['TARGETS'], s) + else: + if key in lvars: + s = lvars[key] + elif key in self.gvars: + s = self.gvars[key] + elif not NameError in AllowableExceptions: + raise_exception(NameError(), lvars['TARGETS'], s) + else: + return + + # Before re-expanding the result, handle + # recursive expansion by copying the local + # variable dictionary and overwriting a null + # string for the value of the variable name + # we just expanded. + lv = lvars.copy() + var = key.split('.')[0] + lv[var] = '' + self.substitute(s, lv, 0) + self.this_word() + elif is_Sequence(s): + for a in s: + self.substitute(a, lvars, 1) + self.next_word() + elif callable(s): + try: + s = s(target=lvars['TARGETS'], + source=lvars['SOURCES'], + env=self.env, + for_signature=(self.mode != SUBST_CMD)) + except TypeError: + # This probably indicates that it's a callable + # object that doesn't match our calling arguments + # (like an Action). + if self.mode == SUBST_RAW: + self.append(s) + return + s = self.conv(s) + self.substitute(s, lvars, within_list) + elif s is None: + self.this_word() + else: + self.append(s) + + def substitute(self, args, lvars, within_list): + """Substitute expansions in an argument or list of arguments. + + This serves as a wrapper for splitting up a string into + separate tokens. + """ + + if is_String(args) and not isinstance(args, CmdStringHolder): + args = str(args) # In case it's a UserString. + args = _separate_args.findall(args) + for a in args: + if a[0] in ' \t\n\r\f\v': + if '\n' in a: + self.next_line() + elif within_list: + self.append(a) + else: + self.next_word() + else: + self.expand(a, lvars, within_list) + else: + self.expand(args, lvars, within_list) + + def next_line(self): + """Arrange for the next word to start a new line. This + is like starting a new word, except that we have to append + another line to the result.""" + collections.UserList.append(self, []) + self.next_word() + + def this_word(self): + """Arrange for the next word to append to the end of the + current last word in the result.""" + self.append = self.add_to_current_word + + def next_word(self): + """Arrange for the next word to start a new word.""" + self.append = self.add_new_word + + def add_to_current_word(self, x): + """Append the string x to the end of the current last word + in the result. If that is not possible, then just add + it as a new word. Make sure the entire concatenated string + inherits the object attributes of x (in particular, the + escape function) by wrapping it as CmdStringHolder.""" + + if not self.in_strip or self.mode != SUBST_SIG: + try: + current_word = self[-1][-1] + except IndexError: + self.add_new_word(x) + else: + # All right, this is a hack and it should probably + # be refactored out of existence in the future. + # The issue is that we want to smoosh words together + # and make one file name that gets escaped if + # we're expanding something like foo$EXTENSION, + # but we don't want to smoosh them together if + # it's something like >$TARGET, because then we'll + # treat the '>' like it's part of the file name. + # So for now, just hard-code looking for the special + # command-line redirection characters... + try: + last_char = str(current_word)[-1] + except IndexError: + last_char = '\0' + if last_char in '<>|': + self.add_new_word(x) + else: + y = current_word + x + + # We used to treat a word appended to a literal + # as a literal itself, but this caused problems + # with interpreting quotes around space-separated + # targets on command lines. Removing this makes + # none of the "substantive" end-to-end tests fail, + # so we'll take this out but leave it commented + # for now in case there's a problem not covered + # by the test cases and we need to resurrect this. + #literal1 = self.literal(self[-1][-1]) + #literal2 = self.literal(x) + y = self.conv(y) + if is_String(y): + #y = CmdStringHolder(y, literal1 or literal2) + y = CmdStringHolder(y, None) + self[-1][-1] = y + + def add_new_word(self, x): + if not self.in_strip or self.mode != SUBST_SIG: + literal = self.literal(x) + x = self.conv(x) + if is_String(x): + x = CmdStringHolder(x, literal) + self[-1].append(x) + self.append = self.add_to_current_word + + def literal(self, x): + try: + l = x.is_literal + except AttributeError: + return None + else: + return l() + + def open_strip(self, x): + """Handle the "open strip" $( token.""" + self.add_strip(x) + self.in_strip = 1 + + def close_strip(self, x): + """Handle the "close strip" $) token.""" + self.add_strip(x) + self.in_strip = None + + if conv is None: + conv = _strconv[mode] + + # Doing this every time is a bit of a waste, since the Executor + # has typically already populated the OverrideEnvironment with + # $TARGET/$SOURCE variables. We're keeping this (for now), though, + # because it supports existing behavior that allows us to call + # an Action directly with an arbitrary target+source pair, which + # we use in Tool/tex.py to handle calling $BIBTEX when necessary. + # If we dropped that behavior (or found another way to cover it), + # we could get rid of this call completely and just rely on the + # Executor setting the variables. + if 'TARGET' not in lvars: + d = subst_dict(target, source) + if d: + lvars = lvars.copy() + lvars.update(d) + + # We're (most likely) going to eval() things. If Python doesn't + # find a __builtins__ value in the global dictionary used for eval(), + # it copies the current global values for you. Avoid this by + # setting it explicitly and then deleting, so we don't pollute the + # construction environment Dictionary(ies) that are typically used + # for expansion. + gvars['__builtins__'] = __builtins__ + + ls = ListSubber(env, mode, conv, gvars) + ls.substitute(strSubst, lvars, 0) + + try: + del gvars['__builtins__'] + except KeyError: + pass + + return ls.data + +def scons_subst_once(strSubst, env, key): + """Perform single (non-recursive) substitution of a single + construction variable keyword. + + This is used when setting a variable when copying or overriding values + in an Environment. We want to capture (expand) the old value before + we override it, so people can do things like: + + env2 = env.Clone(CCFLAGS = '$CCFLAGS -g') + + We do this with some straightforward, brute-force code here... + """ + if isinstance(strSubst, str) and strSubst.find('$') < 0: + return strSubst + + matchlist = ['$' + key, '${' + key + '}'] + val = env.get(key, '') + def sub_match(match, val=val, matchlist=matchlist): + a = match.group(1) + if a in matchlist: + a = val + if is_Sequence(a): + return ' '.join(map(str, a)) + else: + return str(a) + + if is_Sequence(strSubst): + result = [] + for arg in strSubst: + if is_String(arg): + if arg in matchlist: + arg = val + if is_Sequence(arg): + result.extend(arg) + else: + result.append(arg) + else: + result.append(_dollar_exps.sub(sub_match, arg)) + else: + result.append(arg) + return result + elif is_String(strSubst): + return _dollar_exps.sub(sub_match, strSubst) + else: + return strSubst + +# Local Variables: +# tab-width:4 +# indent-tabs-mode:nil +# End: +# vim: set expandtab tabstop=4 shiftwidth=4: |