Function ExpandVariables

tools/gyp/pylib/gyp/input.py:758–1104

(input, phase, variables, build_file)

def ExpandVariables(input, phase, variables, build_file):
    # Look for the pattern that gets expanded into variables
    if phase == PHASE_EARLY:
        variable_re = early_variable_re
        expansion_symbol = "<"
    elif phase == PHASE_LATE:
        variable_re = late_variable_re
        expansion_symbol = ">"
    elif phase == PHASE_LATELATE:
        variable_re = latelate_variable_re
        expansion_symbol = "^"
    else:
        assert False

    input_str = str(input)
    if IsStrCanonicalInt(input_str):
        return int(input_str)

    # Do a quick scan to determine if an expensive regex search is warranted.
    if expansion_symbol not in input_str:
        return input_str

    # Get the entire list of matches as a list of MatchObject instances.
    # (using findall here would return strings instead of MatchObjects).
    matches = list(variable_re.finditer(input_str))
    if not matches:
        return input_str

    output = input_str
    # Reverse the list of matches so that replacements are done right-to-left.
    # That ensures that earlier replacements won't mess up the string in a
    # way that causes later calls to find the earlier substituted text instead
    # of what's intended for replacement.
    matches.reverse()
    for match_group in matches:
        match = match_group.groupdict()
        gyp.DebugOutput(gyp.DEBUG_VARIABLES, "Matches: %r", match)
        # match['replace'] is the substring to look for, match['type']
        # is the character code for the replacement type (< > <! >! <| >| <@
        # >@ <!@ >!@), match['is_array'] contains a '[' for command
        # arrays, and match['content'] is the name of the variable (< >)
        # or command to run (<! >!). match['command_string'] is an optional
        # command string. Currently, only 'pymod_do_main' is supported.

        # run_command is true if a ! variant is used.
        run_command = "!" in match["type"]
        command_string = match["command_string"]

        # file_list is true if a | variant is used.
        file_list = "|" in match["type"]

        # Capture these now so we can adjust them later.
        replace_start = match_group.start("replace")
        replace_end = match_group.end("replace")

        # Find the ending paren, and re-evaluate the contained string.
        (c_start, c_end) = FindEnclosingBracketGroup(input_str[replace_start:])