diff options
Diffstat (limited to 'src/engine/SCons/Action.py')
| -rw-r--r-- | src/engine/SCons/Action.py | 185 |
1 files changed, 148 insertions, 37 deletions
diff --git a/src/engine/SCons/Action.py b/src/engine/SCons/Action.py index c2c1158..cd4bf6a 100644 --- a/src/engine/SCons/Action.py +++ b/src/engine/SCons/Action.py @@ -97,6 +97,7 @@ way for wrapping up the functions. __revision__ = "__FILE__ __REVISION__ __DATE__ __DEVELOPER__" +import cPickle import dis import os import os.path @@ -150,6 +151,138 @@ else: i = i+1 return string.join(result, '') + +def _callable_contents(obj): + """Return the signature contents of a callable Python object. + """ + try: + # Test if obj is a method. + return _function_contents(obj.im_func) + + except AttributeError: + try: + # Test if obj is a callable object. + return _function_contents(obj.__call__.im_func) + + except AttributeError: + try: + # Test if obj is a code object. + return _code_contents(obj) + + except AttributeError: + # Test if obj is a function object. + return _function_contents(obj) + + +def _object_contents(obj): + """Return the signature contents of any Python object. + + We have to handle the case where object contains a code object + since it can be pickled directly. + """ + try: + # Test if obj is a method. + return _function_contents(obj.im_func) + + except AttributeError: + try: + # Test if obj is a callable object. + return _function_contents(obj.__call__.im_func) + + except AttributeError: + try: + # Test if obj is a code object. + return _code_contents(obj) + + except AttributeError: + try: + # Test if obj is a function object. + return _function_contents(obj) + + except AttributeError: + # Should be a pickable Python object. + try: + return cPickle.dumps(obj) + except (cPickle.PicklingError, TypeError): + # This is weird, but it seems that nested classes + # are unpickable. The Python docs say it should + # always be a PicklingError, but some Python + # versions seem to return TypeError. Just do + # the best we can. + return str(obj) + + +def _code_contents(code): + """Return the signature contents of a code object. + + By providing direct access to the code object of the + function, Python makes this extremely easy. Hooray! + + Unfortunately, older versions of Python include line + number indications in the compiled byte code. Boo! + So we remove the line number byte codes to prevent + recompilations from moving a Python function. + """ + + contents = [] + + # The code contents depends on the number of local variables + # but not their actual names. + contents.append("%s,%s" % (code.co_argcount, len(code.co_varnames))) + try: + contents.append(",%s,%s" % (len(code.co_cellvars), len(code.co_freevars))) + except AttributeError: + # Older versions of Python do not support closures. + contents.append(",0,0") + + # The code contents depends on any constants accessed by the + # function. Note that we have to call _object_contents on each + # constants because the code object of nested functions can + # show-up among the constants. + # + # Note that we also always ignore the first entry of co_consts + # which contains the function doc string. We assume that the + # function does not access its doc string. + contents.append(',(' + string.join(map(_object_contents,code.co_consts[1:]),',') + ')') + + # The code contents depends on the variable names used to + # accessed global variable, as changing the variable name changes + # the variable actually accessed and therefore changes the + # function result. + contents.append(',(' + string.join(map(_object_contents,code.co_names),',') + ')') + + + # The code contents depends on its actual code!!! + contents.append(',(' + str(remove_set_lineno_codes(code.co_code)) + ')') + + return string.join(contents, '') + + +def _function_contents(func): + """Return the signature contents of a function.""" + + contents = [_code_contents(func.func_code)] + + # The function contents depends on the value of defaults arguments + if func.func_defaults: + contents.append(',(' + string.join(map(_object_contents,func.func_defaults),',') + ')') + else: + contents.append(',()') + + # The function contents depends on the closure captured cell values. + try: + closure = func.func_closure or [] + except AttributeError: + # Older versions of Python do not support closures. + closure = [] + + #xxx = [_object_contents(x.cell_contents) for x in closure] + xxx = map(lambda x: _object_contents(x.cell_contents), closure) + contents.append(',(' + string.join(xxx, ',') + ')') + + return string.join(contents, '') + + def _actionAppend(act1, act2): # This function knows how to slap two actions together. # Mainly, it handles ListActions by concatenating into @@ -643,6 +776,16 @@ class FunctionAction(_ActionAction): 'accepts (target, source, env) as parameters.') self.execfunction = execfunction + try: + self.funccontents = _callable_contents(execfunction) + except AttributeError: + try: + # See if execfunction will do the heavy lifting for us. + self.gc = execfunction.get_contents + except AttributeError: + # This is weird, just do the best we can. + self.funccontents = _object_contents(execfunction) + apply(_ActionAction.__init__, (self,)+args, kw) self.varlist = kw.get('varlist', []) self.cmdstr = cmdstr @@ -716,46 +859,14 @@ class FunctionAction(_ActionAction): return result def get_contents(self, target, source, env): - """Return the signature contents of this callable action. - - By providing direct access to the code object of the - function, Python makes this extremely easy. Hooray! - - Unfortunately, older versions of Python include line - number indications in the compiled byte code. Boo! - So we remove the line number byte codes to prevent - recompilations from moving a Python function. - """ - execfunction = self.execfunction + """Return the signature contents of this callable action.""" try: - # Test if execfunction is a function. - code = execfunction.func_code.co_code + contents = self.gc(target, source, env) except AttributeError: - try: - # Test if execfunction is a method. - code = execfunction.im_func.func_code.co_code - except AttributeError: - try: - # Test if execfunction is a callable object. - code = execfunction.__call__.im_func.func_code.co_code - except AttributeError: - try: - # See if execfunction will do the heavy lifting for us. - gc = self.execfunction.get_contents - except AttributeError: - # This is weird, just do the best we can. - contents = str(self.execfunction) - else: - contents = gc(target, source, env) - else: - contents = str(code) - else: - contents = str(code) - else: - contents = str(code) - contents = remove_set_lineno_codes(contents) + contents = self.funccontents + return contents + env.subst(string.join(map(lambda v: '${'+v+'}', - self.varlist))) + self.varlist))) def get_implicit_deps(self, target, source, env): return [] |