Source code for SCons.Scanner.C

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"""Dependency scanner for C/C++ code."""

import SCons.Node.FS
import SCons.cpp
import SCons.Util
from . import ClassicCPP, FindPathDirs


[docs]class SConsCPPScanner(SCons.cpp.PreProcessor): """SCons-specific subclass of the cpp.py module's processing. We subclass this so that: 1) we can deal with files represented by Nodes, not strings; 2) we can keep track of the files that are missing. """ def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.missing = []
[docs] def initialize_result(self, fname): self.result = SCons.Util.UniqueList([fname])
[docs] def finalize_result(self, fname): return self.result[1:]
[docs] def find_include_file(self, t): keyword, quote, fname = t result = SCons.Node.FS.find_file(fname, self.searchpath[quote]) if not result: self.missing.append((fname, self.current_file)) return result
[docs] def read_file(self, file): try: with open(str(file.rfile())) as fp: return fp.read() except EnvironmentError as e: self.missing.append((file, self.current_file)) return ''
[docs]def dictify_CPPDEFINES(env): cppdefines = env.get('CPPDEFINES', {}) if cppdefines is None: return {} if SCons.Util.is_Sequence(cppdefines): result = {} for c in cppdefines: if SCons.Util.is_Sequence(c): result[c[0]] = c[1] else: result[c] = None return result if not SCons.Util.is_Dict(cppdefines): return {cppdefines : None} return cppdefines
[docs]class SConsCPPScannerWrapper: """The SCons wrapper around a cpp.py scanner. This is the actual glue between the calling conventions of generic SCons scanners, and the (subclass of) cpp.py class that knows how to look for #include lines with reasonably real C-preprocessor-like evaluation of #if/#ifdef/#else/#elif lines. """ def __init__(self, name, variable): self.name = name self.path = FindPathDirs(variable) def __call__(self, node, env, path=()): cpp = SConsCPPScanner( current=node.get_dir(), cpppath=path, dict=dictify_CPPDEFINES(env) ) result = cpp(node) for included, includer in cpp.missing: SCons.Warnings.warn( SCons.Warnings.DependencyWarning, "No dependency generated for file: %s (included from: %s) " "-- file not found" % (included, includer), ) return result
[docs] def recurse_nodes(self, nodes): return nodes
[docs] def select(self, node): return self
[docs]def CScanner(): """Return a prototype Scanner instance for scanning source files that use the C pre-processor""" # Here's how we would (or might) use the CPP scanner code above that # knows how to evaluate #if/#ifdef/#else/#elif lines when searching # for #includes. This is commented out for now until we add the # right configurability to let users pick between the scanners. # return SConsCPPScannerWrapper("CScanner", "CPPPATH") cs = ClassicCPP( "CScanner", "$CPPSUFFIXES", "CPPPATH", r'^[ \t]*#[ \t]*(?:include|import)[ \t]*(<|")([^>"]+)(>|")', ) return cs
# # ConditionalScanner #
[docs]class SConsCPPConditionalScanner(SCons.cpp.PreProcessor): """SCons-specific subclass of the cpp.py module's processing. We subclass this so that: 1) we can deal with files represented by Nodes, not strings; 2) we can keep track of the files that are missing. """ def __init__(self, *args, **kwargs): super().__init__(*args, **kwargs) self.missing = [] self._known_paths = []
[docs] def initialize_result(self, fname): self.result = SCons.Util.UniqueList([fname])
[docs] def find_include_file(self, t): keyword, quote, fname = t paths = tuple(self._known_paths) + self.searchpath[quote] if quote == '"': paths = (self.current_file.dir,) + paths result = SCons.Node.FS.find_file(fname, paths) if result: result_path = result.get_abspath() for p in self.searchpath[quote]: if result_path.startswith(p.get_abspath()): self._known_paths.append(p) break else: self.missing.append((fname, self.current_file)) return result
[docs] def read_file(self, file): try: with open(str(file.rfile())) as fp: return fp.read() except EnvironmentError: self.missing.append((file, self.current_file)) return ""
[docs]class SConsCPPConditionalScannerWrapper: """ The SCons wrapper around a cpp.py scanner. This is the actual glue between the calling conventions of generic SCons scanners, and the (subclass of) cpp.py class that knows how to look for #include lines with reasonably real C-preprocessor-like evaluation of #if/#ifdef/#else/#elif lines. """ def __init__(self, name, variable): self.name = name self.path = FindPathDirs(variable) def __call__(self, node, env, path=(), depth=-1): cpp = SConsCPPConditionalScanner( current=node.get_dir(), cpppath=path, dict=dictify_CPPDEFINES(env), depth=depth, ) result = cpp(node) for included, includer in cpp.missing: fmt = "No dependency generated for file: %s (included from: %s) -- file not found" SCons.Warnings.warn( SCons.Warnings.DependencyWarning, fmt % (included, includer) ) return result
[docs] def recurse_nodes(self, nodes): return nodes
[docs] def select(self, node): return self
[docs]def CConditionalScanner(): """ Return an advanced conditional Scanner instance for scanning source files Interprets C/C++ Preprocessor conditional syntax (#ifdef, #if, defined, #else, #elif, etc.). """ return SConsCPPConditionalScannerWrapper("CConditionalScanner", "CPPPATH")
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