"""SCons.Subst SCons string substitution. """ # # Copyright (c) 2001, 2002, 2003, 2004, 2005, 2006, 2007 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 2523 2007/12/12 09:37:41 knight" import SCons.compat import re import string import types import UserList import UserString import SCons.Errors from SCons.Util import is_String, is_List, is_Tuple # Indexed by the SUBST_* constants below. _strconv = [SCons.Util.to_String, SCons.Util.to_String, SCons.Util.to_String_for_signature] AllowableExceptions = (IndexError, NameError) def SetAllowableExceptions(*excepts): global AllowableExceptions AllowableExceptions = filter(None, excepts) 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: """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 class SpecialAttrWrapper: """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(UserString.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): UserString.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(list, 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 map(escape, list) class NLWrapper: """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): list = self.list if list is None: list = [] elif not is_List(list) and not is_Tuple(list): list = [list] # The map(self.func) call is what actually turns # a list into appropriate proxies. self.nodelist = SCons.Util.NodeList(map(self.func, list)) self._create_nodelist = self._return_nodelist return self.nodelist _create_nodelist = _gen_nodelist class Targets_or_Sources(UserList.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 UserList.UserList purely so that the is_List() function will identify an object of this class as a list during variable expansion. We're not really using any UserList.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: """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 '' 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: tnl = NLWrapper(target, lambda x: x.get_subst_proxy()) dict['TARGETS'] = Targets_or_Sources(tnl) dict['TARGET'] = Target_or_Source(tnl) else: dict['TARGETS'] = None dict['TARGET'] = None if source: def get_src_subst_proxy(node): try: rfile = node.rfile except AttributeError: pass else: node = rfile() return node.get_subst_proxy() snl = NLWrapper(source, get_src_subst_proxy) dict['SOURCES'] = Targets_or_Sources(snl) dict['SOURCE'] = Target_or_Source(snl) else: dict['SOURCES'] = None dict['SOURCE'] = None 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 ] # 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 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 type(strSubst) == types.StringType and string.find(strSubst, '$') < 0: return strSubst class StringSubber: """A class to construct the results of a scons_subst() call. This binds a specific construction environment, mode, target and source with two methods (substitute() and expand()) that handle the expansion. """ def __init__(self, env, mode, target, source, conv, gvars): self.env = env self.mode = mode self.target = target self.source = source self.conv = conv self.gvars = gvars def expand(self, s, lvars): """Expand a single "token" as necessary, returning an appropriate string containing the expansion. This handles expanding different types of things (strings, lists, callables) appropriately. It calls the wrapper substitute() method to re-expand things as necessary, so that the results of expansions of side-by-side strings still get re-evaluated separately, not smushed together. """ if is_String(s): try: s0, s1 = s[:2] except (IndexError, ValueError): return s if s0 != '$': return s if s1 == '$': return '$' elif s1 in '()': return s else: key = s[1:] if key[0] == '{' or string.find(key, '.') >= 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, self.target, s) else: if lvars.has_key(key): s = lvars[key] elif self.gvars.has_key(key): s = self.gvars[key] elif not NameError in AllowableExceptions: raise_exception(NameError(key), self.target, 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 = string.split(key, '.')[0] lv[var] = '' return self.substitute(s, lv) elif is_List(s) or is_Tuple(s): def func(l, conv=self.conv, substitute=self.substitute, lvars=lvars): return conv(substitute(l, lvars)) r = map(func, s) return string.join(r) elif callable(s): try: s = s(target=self.target, source=self.source, 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): try: def sub_match(match, conv=self.conv, expand=self.expand, lvars=lvars): return conv(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))) try: result = string.join(result, '') except TypeError: if len(result) == 1: result = result[0] 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. 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, target, source, 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 = string.strip(_space_sep.sub(' ', 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(1) class ListSubber(UserList.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, target, source, conv, gvars): UserList.UserList.__init__(self, []) self.env = env self.mode = mode self.target = target self.source = source self.conv = conv self.gvars = gvars if self.mode == SUBST_RAW: self.add_strip = lambda x, s=self: s.append(x) else: self.add_strip = lambda x, s=self: 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 string.find(key, '.') >= 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, self.target, s) else: if lvars.has_key(key): s = lvars[key] elif self.gvars.has_key(key): s = self.gvars[key] elif not NameError in AllowableExceptions: raise_exception(NameError(), self.target, 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 = string.split(key, '.')[0] lv[var] = '' self.substitute(s, lv, 0) self.this_word() elif is_List(s) or is_Tuple(s): for a in s: self.substitute(a, lvars, 1) self.next_word() elif callable(s): try: s = s(target=self.target, source=self.source, 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 = _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.""" UserList.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 $BIBTEX when necessary. # If we dropped that behavior (or found another way to cover it), # we could get rid of this call completely and just rely on the # Executor setting the variables. d = subst_dict(target, source) if d: lvars = lvars.copy() lvars.update(d) # We're (most likely) going to eval() things. If Python doesn't # find a __builtins__ value in the global dictionary used for eval(), # it copies the current global values for you. Avoid this by # setting it explicitly and then deleting, so we don't pollute the # construction environment Dictionary(ies) that are typically used # for expansion. gvars['__builtins__'] = __builtins__ ls = ListSubber(env, mode, target, source, conv, gvars) ls.substitute(strSubst, lvars, 0) try: del gvars['__builtins__'] except KeyError: pass return ls.data def scons_subst_once(strSubst, env, key): """Perform single (non-recursive) substitution of a single construction variable keyword. This is used when setting a variable when copying or overriding values in an Environment. We want to capture (expand) the old value before we override it, so people can do things like: env2 = env.Clone(CCFLAGS = '$CCFLAGS -g') We do this with some straightforward, brute-force code here... """ if type(strSubst) == types.StringType and string.find(strSubst, '$') < 0: return strSubst matchlist = ['$' + 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_List(a) or is_Tuple(a): return string.join(map(str, a)) else: return str(a) if is_List(strSubst) or is_Tuple(strSubst): result = [] for arg in strSubst: if is_String(arg): if arg in matchlist: arg = val if is_List(arg) or is_Tuple(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