python-3.6.zip added from Github

README.cosmo contains the necessary links.

third_party/python/Tools/clinic/cpp.py

@@ -0,0 +1,191 @@
+import re
+import sys
+
+def negate(condition):
+    """
+    Returns a CPP conditional that is the opposite of the conditional passed in.
+    """
+    if condition.startswith('!'):
+        return condition[1:]
+    return "!" + condition
+
+class Monitor:
+    """
+    A simple C preprocessor that scans C source and computes, line by line,
+    what the current C preprocessor #if state is.
+
+    Doesn't handle everything--for example, if you have /* inside a C string,
+    without a matching */ (also inside a C string), or with a */ inside a C
+    string but on another line and with preprocessor macros in between...
+    the parser will get lost.
+
+    Anyway this implementation seems to work well enough for the CPython sources.
+    """
+
+    is_a_simple_defined = re.compile(r'^defined\s*\(\s*[A-Za-z0-9_]+\s*\)$').match
+
+    def __init__(self, filename=None, *, verbose=False):
+        self.stack = []
+        self.in_comment = False
+        self.continuation = None
+        self.line_number = 0
+        self.filename = filename
+        self.verbose = verbose
+
+    def __repr__(self):
+        return ''.join((
+            '<Monitor ',
+            str(id(self)),
+            " line=", str(self.line_number),
+            " condition=", repr(self.condition()),
+            ">"))
+
+    def status(self):
+        return str(self.line_number).rjust(4) + ": " + self.condition()
+
+    def condition(self):
+        """
+        Returns the current preprocessor state, as a single #if condition.
+        """
+        return " && ".join(condition for token, condition in self.stack)
+
+    def fail(self, *a):
+        if self.filename:
+            filename = " " + self.filename
+        else:
+            filename = ''
+        print("Error at" + filename, "line", self.line_number, ":")
+        print("   ", ' '.join(str(x) for x in a))
+        sys.exit(-1)
+
+    def close(self):
+        if self.stack:
+            self.fail("Ended file while still in a preprocessor conditional block!")
+
+    def write(self, s):
+        for line in s.split("\n"):
+            self.writeline(line)
+
+    def writeline(self, line):
+        self.line_number += 1
+        line = line.strip()
+
+        def pop_stack():
+            if not self.stack:
+                self.fail("#" + token + " without matching #if / #ifdef / #ifndef!")
+            return self.stack.pop()
+
+        if self.continuation:
+            line = self.continuation + line
+            self.continuation = None
+
+        if not line:
+            return
+
+        if line.endswith('\\'):
+            self.continuation = line[:-1].rstrip() + " "
+            return
+
+        # we have to ignore preprocessor commands inside comments
+        #
+        # we also have to handle this:
+        #     /* start
+        #     ...
+        #     */   /*    <-- tricky!
+        #     ...
+        #     */
+        # and this:
+        #     /* start
+        #     ...
+        #     */   /* also tricky! */
+        if self.in_comment:
+            if '*/' in line:
+                # snip out the comment and continue
+                #
+                # GCC allows
+                #    /* comment
+                #    */ #include <stdio.h>
+                # maybe other compilers too?
+                _, _, line = line.partition('*/')
+                self.in_comment = False
+
+        while True:
+            if '/*' in line:
+                if self.in_comment:
+                    self.fail("Nested block comment!")
+
+                before, _, remainder = line.partition('/*')
+                comment, comment_ends, after = remainder.partition('*/')
+                if comment_ends:
+                    # snip out the comment
+                    line = before.rstrip() + ' ' + after.lstrip()
+                    continue
+                # comment continues to eol
+                self.in_comment = True
+                line = before.rstrip()
+            break
+
+        # we actually have some // comments
+        # (but block comments take precedence)
+        before, line_comment, comment = line.partition('//')
+        if line_comment:
+            line = before.rstrip()
+
+        if not line.startswith('#'):
+            return
+
+        line = line[1:].lstrip()
+        assert line
+
+        fields = line.split()
+        token = fields[0].lower()
+        condition = ' '.join(fields[1:]).strip()
+
+        if_tokens = {'if', 'ifdef', 'ifndef'}
+        all_tokens = if_tokens | {'elif', 'else', 'endif'}
+
+        if token not in all_tokens:
+            return
+
+        # cheat a little here, to reuse the implementation of if
+        if token == 'elif':
+            pop_stack()
+            token = 'if'
+
+        if token in if_tokens:
+            if not condition:
+                self.fail("Invalid format for #" + token + " line: no argument!")
+            if token == 'if':
+                if not self.is_a_simple_defined(condition):
+                    condition = "(" + condition + ")"
+            else:
+                fields = condition.split()
+                if len(fields) != 1:
+                    self.fail("Invalid format for #" + token + " line: should be exactly one argument!")
+                symbol = fields[0]
+                condition = 'defined(' + symbol + ')'
+                if token == 'ifndef':
+                    condition = '!' + condition
+
+            self.stack.append(("if", condition))
+            if self.verbose:
+                print(self.status())
+            return
+
+        previous_token, previous_condition = pop_stack()
+
+        if token == 'else':
+            self.stack.append(('else', negate(previous_condition)))
+        elif token == 'endif':
+            pass
+        if self.verbose:
+            print(self.status())
+
+if __name__ == '__main__':
+    for filename in sys.argv[1:]:
+        with open(filename, "rt") as f:
+            cpp = Monitor(filename, verbose=True)
+            print()
+            print(filename)
+            for line_number, line in enumerate(f.read().split('\n'), 1):
+                cpp.writeline(line)