utils/abtest.py

   1 #!/usr/bin/env python
   2 #
   3 # Given a previous good compile narrow down miscompiles.
   4 # Expects two directories named "before" and "after" each containing a set of
   5 # assembly or object files where the "after" version is assumed to be broken.
   6 # You also have to provide a script called "link_test". It is called with a list
   7 # of files which should be linked together and result tested. "link_test" should
   8 # returns with exitcode 0 if the linking and testing succeeded.
   9 #
  10 # abtest.py operates by taking all files from the "before" directory and
  11 # in each step replacing one of them with a file from the "bad" directory.
  12 #
  13 # Additionally you can perform the same steps with a single .s file. In this
  14 # mode functions are identified by " -- Begin function FunctionName" and
  15 # " -- End function" markers. The abtest.py then takes all
  16 # function from the file in the "before" directory and replaces one function
  17 # with the corresponding function from the "bad" file in each step.
  18 #
  19 # Example usage to identify miscompiled files:
  20 #    1. Create a link_test script, make it executable. Simple Example:
  21 #          clang "$@" -o /tmp/test && /tmp/test || echo "PROBLEM"
  22 #    2. Run the script to figure out which files are miscompiled:
  23 #       > ./abtest.py
  24 #       somefile.s: ok
  25 #       someotherfile.s: skipped: same content
  26 #       anotherfile.s: failed: './link_test' exitcode != 0
  27 #       ...
  28 # Example usage to identify miscompiled functions inside a file:
  29 #    3. Run the tests on a single file (assuming before/file.s and
  30 #       after/file.s exist)
  31 #       > ./abtest.py file.s
  32 #       funcname1 [0/XX]: ok
  33 #       funcname2 [1/XX]: ok
  34 #       funcname3 [2/XX]: skipped: same content
  35 #       funcname4 [3/XX]: failed: './link_test' exitcode != 0
  36 #       ...
  37 from fnmatch import filter
  38 from sys import stderr
  39 import argparse
  40 import filecmp
  41 import os
  42 import subprocess
  43 import sys
  44
  45 LINKTEST="./link_test"
  46 ESCAPE="\033[%sm"
  47 BOLD=ESCAPE % "1"
  48 RED=ESCAPE % "31"
  49 NORMAL=ESCAPE % "0"
  50 FAILED=RED+"failed"+NORMAL
  51
  52 def find(dir, file_filter=None):
  53     files = [walkdir[0]+"/"+file for walkdir in os.walk(dir) for file in walkdir[2]]
  54     if file_filter != None:
  55         files = filter(files, file_filter)
  56     return files
  57
  58 def error(message):
  59     stderr.write("Error: %s\n" % (message,))
  60
  61 def warn(message):
  62     stderr.write("Warning: %s\n" % (message,))
  63
  64 def extract_functions(file):
  65     functions = []
  66     in_function = None
  67     for line in open(file):
  68         marker = line.find(" -- Begin function ")
  69         if marker != -1:
  70             if in_function != None:
  71                 warn("Missing end of function %s" % (in_function,))
  72             funcname = line[marker + 19:-1]
  73             in_function = funcname
  74             text = line
  75             continue
  76
  77         marker = line.find(" -- End function")
  78         if marker != -1:
  79             text += line
  80             functions.append( (in_function, text) )
  81             in_function = None
  82             continue
  83
  84         if in_function != None:
  85             text += line
  86     return functions
  87
  88 def replace_function(file, function, replacement, dest):
  89     out = open(dest, "w")
  90     skip = False
  91     found = False
  92     in_function = None
  93     for line in open(file):
  94         marker = line.find(" -- Begin function ")
  95         if marker != -1:
  96             if in_function != None:
  97                 warn("Missing end of function %s" % (in_function,))
  98             funcname = line[marker + 19:-1]
  99             in_function = funcname
 100             if in_function == function:
 101                 out.write(replacement)
 102                 skip = True
 103         else:
 104             marker = line.find(" -- End function")
 105             if marker != -1:
 106                 in_function = None
 107                 if skip:
 108                     skip = False
 109                     continue
 110
 111         if not skip:
 112             out.write(line)
 113
 114 def announce_test(name):
 115     stderr.write("%s%s%s: " % (BOLD, name, NORMAL))
 116     stderr.flush()
 117
 118 def announce_result(result, info):
 119     stderr.write(result)
 120     if info != "":
 121         stderr.write(": %s" % info)
 122     stderr.write("\n")
 123     stderr.flush()
 124
 125 def testrun(files):
 126     linkline="%s %s" % (LINKTEST, " ".join(files),)
 127     res = subprocess.call(linkline, shell=True)
 128     if res != 0:
 129         announce_result(FAILED, "'%s' exitcode != 0" % LINKTEST)
 130         return False
 131     else:
 132         announce_result("ok", "")
 133         return True
 134
 135 def check_files():
 136     """Check files mode"""
 137     for i in range(0, len(NO_PREFIX)):
 138         f = NO_PREFIX[i]
 139         b=baddir+"/"+f
 140         if b not in BAD_FILES:
 141             warn("There is no corresponding file to '%s' in %s" \
 142                  % (gooddir+"/"+f, baddir))
 143             continue
 144
 145         announce_test(f + " [%s/%s]" % (i+1, len(NO_PREFIX)))
 146
 147         # combine files (everything from good except f)
 148         testfiles=[]
 149         skip=False
 150         for c in NO_PREFIX:
 151             badfile = baddir+"/"+c
 152             goodfile = gooddir+"/"+c
 153             if c == f:
 154                 testfiles.append(badfile)
 155                 if filecmp.cmp(goodfile, badfile):
 156                     announce_result("skipped", "same content")
 157                     skip = True
 158                     break
 159             else:
 160                 testfiles.append(goodfile)
 161         if skip:
 162             continue
 163         testrun(testfiles)
 164
 165 def check_functions_in_file(base, goodfile, badfile):
 166     functions = extract_functions(goodfile)
 167     if len(functions) == 0:
 168         warn("Couldn't find any function in %s, missing annotations?" % (goodfile,))
 169         return
 170     badfunctions = dict(extract_functions(badfile))
 171     if len(functions) == 0:
 172         warn("Couldn't find any function in %s, missing annotations?" % (badfile,))
 173         return
 174
 175     COMBINED="/tmp/combined.s"
 176     i = 0
 177     for (func,func_text) in functions:
 178         announce_test(func + " [%s/%s]" % (i+1, len(functions)))
 179         i+=1
 180         if func not in badfunctions:
 181             warn("Function '%s' missing from bad file" % func)
 182             continue
 183         if badfunctions[func] == func_text:
 184             announce_result("skipped", "same content")
 185             continue
 186         replace_function(goodfile, func, badfunctions[func], COMBINED)
 187         testfiles=[]
 188         for c in NO_PREFIX:
 189             if c == base:
 190                 testfiles.append(COMBINED)
 191                 continue
 192             testfiles.append(gooddir + "/" + c)
 193
 194         testrun(testfiles)
 195
 196 parser = argparse.ArgumentParser()
 197 parser.add_argument('--a', dest='dir_a', default='before')
 198 parser.add_argument('--b', dest='dir_b', default='after')
 199 parser.add_argument('--insane', help='Skip sanity check', action='store_true')
 200 parser.add_argument('file', metavar='file', nargs='?')
 201 config = parser.parse_args()
 202
 203 gooddir=config.dir_a
 204 baddir=config.dir_b
 205
 206 BAD_FILES=find(baddir, "*")
 207 GOOD_FILES=find(gooddir, "*")
 208 NO_PREFIX=sorted([x[len(gooddir)+1:] for x in GOOD_FILES])
 209
 210 # "Checking whether build environment is sane ..."
 211 if not config.insane:
 212     announce_test("sanity check")
 213     if not os.access(LINKTEST, os.X_OK):
 214         error("Expect '%s' to be present and executable" % (LINKTEST,))
 215         exit(1)
 216
 217     res = testrun(GOOD_FILES)
 218     if not res:
 219         # "build environment is grinning and holding a spatula. Guess not."
 220         linkline="%s %s" % (LINKTEST, " ".join(GOOD_FILES),)
 221         stderr.write("\n%s\n\n" % linkline)
 222         stderr.write("Returned with exitcode != 0\n")
 223         sys.exit(1)
 224
 225 if config.file is not None:
 226     # File exchange mode
 227     goodfile = gooddir+"/"+config.file
 228     badfile = baddir+"/"+config.file
 229     check_functions_in_file(config.file, goodfile, badfile)
 230 else:
 231     # Function exchange mode
 232     check_files()