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+#
+# Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 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/cpp.py 4577 2009/12/27 19:43:56 scons"
+
+__doc__ = """
+SCons C Pre-Processor module
+"""
+
+# TODO(1.5): remove this import
+# This module doesn't use anything from SCons by name, but we import SCons
+# here to pull in zip() from the SCons.compat layer for early Pythons.
+import SCons
+
+import os
+import re
+import string
+
+#
+# First "subsystem" of regular expressions that we set up:
+#
+# Stuff to turn the C preprocessor directives in a file's contents into
+# a list of tuples that we can process easily.
+#
+
+# A table of regular expressions that fetch the arguments from the rest of
+# a C preprocessor line. Different directives have different arguments
+# that we want to fetch, using the regular expressions to which the lists
+# of preprocessor directives map.
+cpp_lines_dict = {
+ # Fetch the rest of a #if/#elif/#ifdef/#ifndef as one argument,
+ # separated from the keyword by white space.
+ ('if', 'elif', 'ifdef', 'ifndef',)
+ : '\s+(.+)',
+
+ # Fetch the rest of a #import/#include/#include_next line as one
+ # argument, with white space optional.
+ ('import', 'include', 'include_next',)
+ : '\s*(.+)',
+
+ # We don't care what comes after a #else or #endif line.
+ ('else', 'endif',) : '',
+
+ # Fetch three arguments from a #define line:
+ # 1) The #defined keyword.
+ # 2) The optional parentheses and arguments (if it's a function-like
+ # macro, '' if it's not).
+ # 3) The expansion value.
+ ('define',) : '\s+([_A-Za-z][_A-Za-z0-9_]*)(\([^)]*\))?\s*(.*)',
+
+ # Fetch the #undefed keyword from a #undef line.
+ ('undef',) : '\s+([_A-Za-z][A-Za-z0-9_]*)',
+}
+
+# Create a table that maps each individual C preprocessor directive to
+# the corresponding compiled regular expression that fetches the arguments
+# we care about.
+Table = {}
+for op_list, expr in cpp_lines_dict.items():
+ e = re.compile(expr)
+ for op in op_list:
+ Table[op] = e
+del e
+del op
+del op_list
+
+# Create a list of the expressions we'll use to match all of the
+# preprocessor directives. These are the same as the directives
+# themselves *except* that we must use a negative lookahead assertion
+# when matching "if" so it doesn't match the "if" in "ifdef."
+override = {
+ 'if' : 'if(?!def)',
+}
+l = map(lambda x, o=override: o.get(x, x), Table.keys())
+
+
+# Turn the list of expressions into one big honkin' regular expression
+# that will match all the preprocessor lines at once. This will return
+# a list of tuples, one for each preprocessor line. The preprocessor
+# directive will be the first element in each tuple, and the rest of
+# the line will be the second element.
+e = '^\s*#\s*(' + string.join(l, '|') + ')(.*)$'
+
+# And last but not least, compile the expression.
+CPP_Expression = re.compile(e, re.M)
+
+
+
+
+#
+# Second "subsystem" of regular expressions that we set up:
+#
+# Stuff to translate a C preprocessor expression (as found on a #if or
+# #elif line) into an equivalent Python expression that we can eval().
+#
+
+# A dictionary that maps the C representation of Boolean operators
+# to their Python equivalents.
+CPP_to_Python_Ops_Dict = {
+ '!' : ' not ',
+ '!=' : ' != ',
+ '&&' : ' and ',
+ '||' : ' or ',
+ '?' : ' and ',
+ ':' : ' or ',
+ '\r' : '',
+}
+
+CPP_to_Python_Ops_Sub = lambda m, d=CPP_to_Python_Ops_Dict: d[m.group(0)]
+
+# We have to sort the keys by length so that longer expressions
+# come *before* shorter expressions--in particular, "!=" must
+# come before "!" in the alternation. Without this, the Python
+# re module, as late as version 2.2.2, empirically matches the
+# "!" in "!=" first, instead of finding the longest match.
+# What's up with that?
+l = CPP_to_Python_Ops_Dict.keys()
+l.sort(lambda a, b: cmp(len(b), len(a)))
+
+# Turn the list of keys into one regular expression that will allow us
+# to substitute all of the operators at once.
+expr = string.join(map(re.escape, l), '|')
+
+# ...and compile the expression.
+CPP_to_Python_Ops_Expression = re.compile(expr)
+
+# A separate list of expressions to be evaluated and substituted
+# sequentially, not all at once.
+CPP_to_Python_Eval_List = [
+ ['defined\s+(\w+)', '__dict__.has_key("\\1")'],
+ ['defined\s*\((\w+)\)', '__dict__.has_key("\\1")'],
+ ['/\*.*\*/', ''],
+ ['/\*.*', ''],
+ ['//.*', ''],
+ ['(0x[0-9A-Fa-f]*)[UL]+', '\\1L'],
+]
+
+# Replace the string representations of the regular expressions in the
+# list with compiled versions.
+for l in CPP_to_Python_Eval_List:
+ l[0] = re.compile(l[0])
+
+# Wrap up all of the above into a handy function.
+def CPP_to_Python(s):
+ """
+ Converts a C pre-processor expression into an equivalent
+ Python expression that can be evaluated.
+ """
+ s = CPP_to_Python_Ops_Expression.sub(CPP_to_Python_Ops_Sub, s)
+ for expr, repl in CPP_to_Python_Eval_List:
+ s = expr.sub(repl, s)
+ return s
+
+
+
+del expr
+del l
+del override
+
+
+
+class FunctionEvaluator:
+ """
+ Handles delayed evaluation of a #define function call.
+ """
+ def __init__(self, name, args, expansion):
+ """
+ Squirrels away the arguments and expansion value of a #define
+ macro function for later evaluation when we must actually expand
+ a value that uses it.
+ """
+ self.name = name
+ self.args = function_arg_separator.split(args)
+ try:
+ expansion = string.split(expansion, '##')
+ except (AttributeError, TypeError):
+ # Python 1.5 throws TypeError if "expansion" isn't a string,
+ # later versions throw AttributeError.
+ pass
+ self.expansion = expansion
+ def __call__(self, *values):
+ """
+ Evaluates the expansion of a #define macro function called
+ with the specified values.
+ """
+ if len(self.args) != len(values):
+ raise ValueError, "Incorrect number of arguments to `%s'" % self.name
+ # Create a dictionary that maps the macro arguments to the
+ # corresponding values in this "call." We'll use this when we
+ # eval() the expansion so that arguments will get expanded to
+ # the right values.
+ locals = {}
+ for k, v in zip(self.args, values):
+ locals[k] = v
+
+ parts = []
+ for s in self.expansion:
+ if not s in self.args:
+ s = repr(s)
+ parts.append(s)
+ statement = string.join(parts, ' + ')
+
+ return eval(statement, globals(), locals)
+
+
+
+# Find line continuations.
+line_continuations = re.compile('\\\\\r?\n')
+
+# Search for a "function call" macro on an expansion. Returns the
+# two-tuple of the "function" name itself, and a string containing the
+# arguments within the call parentheses.
+function_name = re.compile('(\S+)\(([^)]*)\)')
+
+# Split a string containing comma-separated function call arguments into
+# the separate arguments.
+function_arg_separator = re.compile(',\s*')
+
+
+
+class PreProcessor:
+ """
+ The main workhorse class for handling C pre-processing.
+ """
+ def __init__(self, current=os.curdir, cpppath=(), dict={}, all=0):
+ global Table
+
+ cpppath = tuple(cpppath)
+
+ self.searchpath = {
+ '"' : (current,) + cpppath,
+ '<' : cpppath + (current,),
+ }
+
+ # Initialize our C preprocessor namespace for tracking the
+ # values of #defined keywords. We use this namespace to look
+ # for keywords on #ifdef/#ifndef lines, and to eval() the
+ # expressions on #if/#elif lines (after massaging them from C to
+ # Python).
+ self.cpp_namespace = dict.copy()
+ self.cpp_namespace['__dict__'] = self.cpp_namespace
+
+ if all:
+ self.do_include = self.all_include
+
+ # For efficiency, a dispatch table maps each C preprocessor
+ # directive (#if, #define, etc.) to the method that should be
+ # called when we see it. We accomodate state changes (#if,
+ # #ifdef, #ifndef) by pushing the current dispatch table on a
+ # stack and changing what method gets called for each relevant
+ # directive we might see next at this level (#else, #elif).
+ # #endif will simply pop the stack.
+ d = {
+ 'scons_current_file' : self.scons_current_file
+ }
+ for op in Table.keys():
+ d[op] = getattr(self, 'do_' + op)
+ self.default_table = d
+
+ # Controlling methods.
+
+ def tupleize(self, contents):
+ """
+ Turns the contents of a file into a list of easily-processed
+ tuples describing the CPP lines in the file.
+
+ The first element of each tuple is the line's preprocessor
+ directive (#if, #include, #define, etc., minus the initial '#').
+ The remaining elements are specific to the type of directive, as
+ pulled apart by the regular expression.
+ """
+ global CPP_Expression, Table
+ contents = line_continuations.sub('', contents)
+ cpp_tuples = CPP_Expression.findall(contents)
+ return map(lambda m, t=Table:
+ (m[0],) + t[m[0]].match(m[1]).groups(),
+ cpp_tuples)
+
+ def __call__(self, file):
+ """
+ Pre-processes a file.
+
+ This is the main public entry point.
+ """
+ self.current_file = file
+ return self.process_contents(self.read_file(file), file)
+
+ def process_contents(self, contents, fname=None):
+ """
+ Pre-processes a file contents.
+
+ This is the main internal entry point.
+ """
+ self.stack = []
+ self.dispatch_table = self.default_table.copy()
+ self.current_file = fname
+ self.tuples = self.tupleize(contents)
+
+ self.initialize_result(fname)
+ while self.tuples:
+ t = self.tuples.pop(0)
+ # Uncomment to see the list of tuples being processed (e.g.,
+ # to validate the CPP lines are being translated correctly).
+ #print t
+ self.dispatch_table[t[0]](t)
+ return self.finalize_result(fname)
+
+ # Dispatch table stack manipulation methods.
+
+ def save(self):
+ """
+ Pushes the current dispatch table on the stack and re-initializes
+ the current dispatch table to the default.
+ """
+ self.stack.append(self.dispatch_table)
+ self.dispatch_table = self.default_table.copy()
+
+ def restore(self):
+ """
+ Pops the previous dispatch table off the stack and makes it the
+ current one.
+ """
+ try: self.dispatch_table = self.stack.pop()
+ except IndexError: pass
+
+ # Utility methods.
+
+ def do_nothing(self, t):
+ """
+ Null method for when we explicitly want the action for a
+ specific preprocessor directive to do nothing.
+ """
+ pass
+
+ def scons_current_file(self, t):
+ self.current_file = t[1]
+
+ def eval_expression(self, t):
+ """
+ Evaluates a C preprocessor expression.
+
+ This is done by converting it to a Python equivalent and
+ eval()ing it in the C preprocessor namespace we use to
+ track #define values.
+ """
+ t = CPP_to_Python(string.join(t[1:]))
+ try: return eval(t, self.cpp_namespace)
+ except (NameError, TypeError): return 0
+
+ def initialize_result(self, fname):
+ self.result = [fname]
+
+ def finalize_result(self, fname):
+ return self.result[1:]
+
+ def find_include_file(self, t):
+ """
+ Finds the #include file for a given preprocessor tuple.
+ """
+ fname = t[2]
+ for d in self.searchpath[t[1]]:
+ if d == os.curdir:
+ f = fname
+ else:
+ f = os.path.join(d, fname)
+ if os.path.isfile(f):
+ return f
+ return None
+
+ def read_file(self, file):
+ return open(file).read()
+
+ # Start and stop processing include lines.
+
+ def start_handling_includes(self, t=None):
+ """
+ Causes the PreProcessor object to start processing #import,
+ #include and #include_next lines.
+
+ This method will be called when a #if, #ifdef, #ifndef or #elif
+ evaluates True, or when we reach the #else in a #if, #ifdef,
+ #ifndef or #elif block where a condition already evaluated
+ False.
+
+ """
+ d = self.dispatch_table
+ d['import'] = self.do_import
+ d['include'] = self.do_include
+ d['include_next'] = self.do_include
+
+ def stop_handling_includes(self, t=None):
+ """
+ Causes the PreProcessor object to stop processing #import,
+ #include and #include_next lines.
+
+ This method will be called when a #if, #ifdef, #ifndef or #elif
+ evaluates False, or when we reach the #else in a #if, #ifdef,
+ #ifndef or #elif block where a condition already evaluated True.
+ """
+ d = self.dispatch_table
+ d['import'] = self.do_nothing
+ d['include'] = self.do_nothing
+ d['include_next'] = self.do_nothing
+
+ # Default methods for handling all of the preprocessor directives.
+ # (Note that what actually gets called for a given directive at any
+ # point in time is really controlled by the dispatch_table.)
+
+ def _do_if_else_condition(self, condition):
+ """
+ Common logic for evaluating the conditions on #if, #ifdef and
+ #ifndef lines.
+ """
+ self.save()
+ d = self.dispatch_table
+ if condition:
+ self.start_handling_includes()
+ d['elif'] = self.stop_handling_includes
+ d['else'] = self.stop_handling_includes
+ else:
+ self.stop_handling_includes()
+ d['elif'] = self.do_elif
+ d['else'] = self.start_handling_includes
+
+ def do_ifdef(self, t):
+ """
+ Default handling of a #ifdef line.
+ """
+ self._do_if_else_condition(self.cpp_namespace.has_key(t[1]))
+
+ def do_ifndef(self, t):
+ """
+ Default handling of a #ifndef line.
+ """
+ self._do_if_else_condition(not self.cpp_namespace.has_key(t[1]))
+
+ def do_if(self, t):
+ """
+ Default handling of a #if line.
+ """
+ self._do_if_else_condition(self.eval_expression(t))
+
+ def do_elif(self, t):
+ """
+ Default handling of a #elif line.
+ """
+ d = self.dispatch_table
+ if self.eval_expression(t):
+ self.start_handling_includes()
+ d['elif'] = self.stop_handling_includes
+ d['else'] = self.stop_handling_includes
+
+ def do_else(self, t):
+ """
+ Default handling of a #else line.
+ """
+ pass
+
+ def do_endif(self, t):
+ """
+ Default handling of a #endif line.
+ """
+ self.restore()
+
+ def do_define(self, t):
+ """
+ Default handling of a #define line.
+ """
+ _, name, args, expansion = t
+ try:
+ expansion = int(expansion)
+ except (TypeError, ValueError):
+ pass
+ if args:
+ evaluator = FunctionEvaluator(name, args[1:-1], expansion)
+ self.cpp_namespace[name] = evaluator
+ else:
+ self.cpp_namespace[name] = expansion
+
+ def do_undef(self, t):
+ """
+ Default handling of a #undef line.
+ """
+ try: del self.cpp_namespace[t[1]]
+ except KeyError: pass
+
+ def do_import(self, t):
+ """
+ Default handling of a #import line.
+ """
+ # XXX finish this -- maybe borrow/share logic from do_include()...?
+ pass
+
+ def do_include(self, t):
+ """
+ Default handling of a #include line.
+ """
+ t = self.resolve_include(t)
+ include_file = self.find_include_file(t)
+ if include_file:
+ #print "include_file =", include_file
+ self.result.append(include_file)
+ contents = self.read_file(include_file)
+ new_tuples = [('scons_current_file', include_file)] + \
+ self.tupleize(contents) + \
+ [('scons_current_file', self.current_file)]
+ self.tuples[:] = new_tuples + self.tuples
+
+ # Date: Tue, 22 Nov 2005 20:26:09 -0500
+ # From: Stefan Seefeld <seefeld@sympatico.ca>
+ #
+ # By the way, #include_next is not the same as #include. The difference
+ # being that #include_next starts its search in the path following the
+ # path that let to the including file. In other words, if your system
+ # include paths are ['/foo', '/bar'], and you are looking at a header
+ # '/foo/baz.h', it might issue an '#include_next <baz.h>' which would
+ # correctly resolve to '/bar/baz.h' (if that exists), but *not* see
+ # '/foo/baz.h' again. See http://www.delorie.com/gnu/docs/gcc/cpp_11.html
+ # for more reasoning.
+ #
+ # I have no idea in what context 'import' might be used.
+
+ # XXX is #include_next really the same as #include ?
+ do_include_next = do_include
+
+ # Utility methods for handling resolution of include files.
+
+ def resolve_include(self, t):
+ """Resolve a tuple-ized #include line.
+
+ This handles recursive expansion of values without "" or <>
+ surrounding the name until an initial " or < is found, to handle
+ #include FILE
+ where FILE is a #define somewhere else.
+ """
+ s = t[1]
+ while not s[0] in '<"':
+ #print "s =", s
+ try:
+ s = self.cpp_namespace[s]
+ except KeyError:
+ m = function_name.search(s)
+ s = self.cpp_namespace[m.group(1)]
+ if callable(s):
+ args = function_arg_separator.split(m.group(2))
+ s = apply(s, args)
+ if not s:
+ return None
+ return (t[0], s[0], s[1:-1])
+
+ def all_include(self, t):
+ """
+ """
+ self.result.append(self.resolve_include(t))
+
+class DumbPreProcessor(PreProcessor):
+ """A preprocessor that ignores all #if/#elif/#else/#endif directives
+ and just reports back *all* of the #include files (like the classic
+ SCons scanner did).
+
+ This is functionally equivalent to using a regular expression to
+ find all of the #include lines, only slower. It exists mainly as
+ an example of how the main PreProcessor class can be sub-classed
+ to tailor its behavior.
+ """
+ def __init__(self, *args, **kw):
+ apply(PreProcessor.__init__, (self,)+args, kw)
+ d = self.default_table
+ for func in ['if', 'elif', 'else', 'endif', 'ifdef', 'ifndef']:
+ d[func] = d[func] = self.do_nothing
+
+del __revision__
+
+# Local Variables:
+# tab-width:4
+# indent-tabs-mode:nil
+# End:
+# vim: set expandtab tabstop=4 shiftwidth=4: