Split out and improve the ad-hoc parsing and disassembly tool

1 files changed, 177 insertions, 0 deletions

diff --git a/lab/parser.py b/lab/parser.py
new file mode 100644
index 00000000..67c41e80
--- /dev/null
+++ b/lab/parser.py
@@ -0,0 +1,177 @@
+"""Parser.py: a main for invoking code in coverage/parser.py"""
+
+import glob, os, sys
+from optparse import OptionParser
+
+import disgen
+
+from coverage.misc import CoverageException
+from coverage.parser import ByteParser, CodeParser
+
+
+class AdHocMain(object):
+    """An ad-hoc main for code parsing experiments."""
+
+    def main(self, args):
+        """A main function for trying the code from the command line."""
+
+        parser = OptionParser()
+        parser.add_option(
+            "-c", action="store_true", dest="chunks",
+            help="Show basic block chunks"
+            )
+        parser.add_option(
+            "-d", action="store_true", dest="dis",
+            help="Disassemble"
+            )
+        parser.add_option(
+            "-R", action="store_true", dest="recursive",
+            help="Recurse to find source files"
+            )
+        parser.add_option(
+            "-s", action="store_true", dest="source",
+            help="Show analyzed source"
+            )
+        parser.add_option(
+            "-t", action="store_true", dest="tokens",
+            help="Show tokens"
+            )
+
+        options, args = parser.parse_args()
+        if options.recursive:
+            if args:
+                root = args[0]
+            else:
+                root = "."
+            for root, _, _ in os.walk(root):
+                for f in glob.glob(root + "/*.py"):
+                    self.adhoc_one_file(options, f)
+        else:
+            self.adhoc_one_file(options, args[0])
+
+    def adhoc_one_file(self, options, filename):
+        """Process just one file."""
+
+        if options.dis or options.chunks:
+            try:
+                bp = ByteParser(filename=filename)
+            except CoverageException:
+                _, err, _ = sys.exc_info()
+                print("%s" % (err,))
+                return
+
+        if options.dis:
+            print("Main code:")
+            self.disassemble(bp)
+
+        if options.chunks:
+            chunks = bp._all_chunks()
+            if options.recursive:
+                print("%6d: %s" % (len(chunks), filename))
+            else:
+                print("Chunks: %r" % chunks)
+                arcs = bp._all_arcs()
+                print("Arcs: %r" % sorted(arcs))
+
+        if options.source or options.tokens:
+            cp = CodeParser(filename=filename, exclude=r"no\s*cover")
+            cp.show_tokens = options.tokens
+            cp._raw_parse()
+
+            if options.source:
+                if options.chunks:
+                    arc_width, arc_chars = self.arc_ascii_art(arcs)
+                else:
+                    arc_width, arc_chars = 0, {}
+
+                exit_counts = cp.exit_counts()
+
+                for i, ltext in enumerate(cp.lines):
+                    lineno = i+1
+                    m0 = m1 = m2 = m3 = a = ' '
+                    if lineno in cp.statement_starts:
+                        m0 = '-'
+                    exits = exit_counts.get(lineno, 0)
+                    if exits > 1:
+                        m1 = str(exits)
+                    if lineno in cp.docstrings:
+                        m2 = '"'
+                    if lineno in cp.classdefs:
+                        m2 = 'C'
+                    if lineno in cp.excluded:
+                        m3 = 'x'
+                    a = arc_chars.get(lineno, '').ljust(arc_width)
+                    print("%4d %s%s%s%s%s %s" %
+                                (lineno, m0, m1, m2, m3, a, ltext)
+                        )
+
+    def disassemble(self, byte_parser):
+        """Disassemble code, for ad-hoc experimenting."""
+
+        for bp in byte_parser.child_parsers():
+            chunks = bp._split_into_chunks()
+            chunkd = dict((chunk.byte, chunk) for chunk in chunks)
+            if bp.text:
+                srclines = bp.text.splitlines()
+            else:
+                srclines = None
+            print("\n%s: " % bp.code)
+            for disline in disgen.disgen(bp.code):
+                if disline.first:
+                    if srclines:
+                        print("%80s%s" % ("", srclines[disline.lineno-1]))
+                    elif disline.offset > 0:
+                        print("")
+                line = disgen.format_dis_line(disline)
+                chunk = chunkd.get(disline.offset)
+                if chunk:
+                    exits = " ".join(str(e) for e in sorted(chunk.exits))
+                    chunkstr = ": %s" % exits
+                else:
+                    chunkstr = ""
+                print("%-70s%s" % (line, chunkstr))
+
+        print("")
+
+    def arc_ascii_art(self, arcs):
+        """Draw arcs as ascii art.
+
+        Returns a width of characters needed to draw all the arcs, and a
+        dictionary mapping line numbers to ascii strings to draw for that line.
+
+        """
+        arc_chars = {}
+        for lfrom, lto in sorted(arcs):
+            if lfrom < 0:
+                arc_chars[lto] = arc_chars.get(lto, '') + 'v'
+            elif lto < 0:
+                arc_chars[lfrom] = arc_chars.get(lfrom, '') + '^'
+            else:
+                if lfrom == lto - 1:
+                    # Don't show obvious arcs.
+                    continue
+                if lfrom < lto:
+                    l1, l2 = lfrom, lto
+                else:
+                    l1, l2 = lto, lfrom
+                w = max([len(arc_chars.get(l, '')) for l in range(l1, l2+1)])
+                for l in range(l1, l2+1):
+                    if l == lfrom:
+                        ch = '<'
+                    elif l == lto:
+                        ch = '>'
+                    else:
+                        ch = '|'
+                    arc_chars[l] = arc_chars.get(l, '').ljust(w) + ch
+                arc_width = 0
+
+        if arc_chars:
+            arc_width = max([len(a) for a in arc_chars.values()])
+        else:
+            arc_width = 0
+
+        return arc_width, arc_chars
+
+if __name__ == '__main__':
+    AdHocMain().main(sys.argv[1:])
+