1 files changed, 210 insertions, 0 deletions
diff --git a/clang/utils/CmpDriver b/clang/utils/CmpDriver
new file mode 100755
index 0000000..2533f54
--- /dev/null
+++ b/clang/utils/CmpDriver
@@ -0,0 +1,210 @@
+#!/usr/bin/env python
+
+import subprocess
+
+def splitArgs(s):
+    it = iter(s)
+    current = ''
+    inQuote = False
+    for c in it:
+        if c == '"':
+            if inQuote:
+                inQuote = False
+                yield current + '"'
+            else:
+                inQuote = True
+                current = '"'
+        elif inQuote:
+            if c == '\\':
+                current += c
+                current += it.next()
+            else:
+                current += c
+        elif not c.isspace():
+            yield c
+
+def insertMinimumPadding(a, b, dist):
+    """insertMinimumPadding(a,b) -> (a',b')
+
+    Return two lists of equal length, where some number of Nones have
+    been inserted into the shorter list such that sum(map(dist, a',
+    b')) is minimized.
+
+    Assumes dist(X, Y) -> int and non-negative.
+    """
+    
+    def cost(a, b):
+        return sum(map(dist, a + [None] * (len(b) - len(a)), b))
+
+    # Normalize so a is shortest.
+    if len(b) < len(a):
+        b, a = insertMinimumPadding(b, a, dist)
+        return a,b
+
+    # For each None we have to insert...
+    for i in range(len(b) - len(a)):
+        # For each position we could insert it...
+        current = cost(a, b)
+        best = None
+        for j in range(len(a) + 1):
+            a_0 = a[:j] + [None] + a[j:]
+            candidate = cost(a_0, b)
+            if best is None or candidate < best[0]:
+                best = (candidate, a_0, j)
+        a = best[1]
+    return a,b
+
+class ZipperDiff(object):
+    """ZipperDiff - Simple (slow) diff only accommodating inserts."""
+    
+    def __init__(self, a, b):
+        self.a = a
+        self.b = b
+
+    def dist(self, a, b):
+        return a != b
+
+    def getDiffs(self):
+        a,b =  insertMinimumPadding(self.a, self.b, self.dist)
+        for aElt,bElt in zip(a,b):
+            if self.dist(aElt, bElt):
+                yield aElt,bElt
+
+class DriverZipperDiff(ZipperDiff):
+    def isTempFile(self, filename):
+        if filename[0] != '"' or filename[-1] != '"':
+            return False
+        return (filename.startswith('/tmp/', 1) or
+                filename.startswith('/var/', 1))
+
+    def dist(self, a, b):
+        if a and b and self.isTempFile(a) and self.isTempFile(b):
+            return 0
+        return super(DriverZipperDiff, self).dist(a,b)        
+
+class CompileInfo:
+    def __init__(self, out, err, res):
+        self.commands = []
+        
+        # Standard out isn't used for much.
+        self.stdout = out
+        self.stderr = ''
+
+        # FIXME: Compare error messages as well.
+        for ln in err.split('\n'):
+            if (ln == 'Using built-in specs.' or
+                ln.startswith('Target: ') or
+                ln.startswith('Configured with: ') or
+                ln.startswith('Thread model: ') or
+                ln.startswith('gcc version') or
+                ln.startswith('clang version')):
+                pass
+            elif ln.strip().startswith('"'):
+                self.commands.append(list(splitArgs(ln)))
+            else:
+                self.stderr += ln + '\n'
+        
+        self.stderr = self.stderr.strip()
+        self.exitCode = res
+
+def captureDriverInfo(cmd, args):
+    p = subprocess.Popen([cmd,'-###'] + args,
+                         stdin=None,
+                         stdout=subprocess.PIPE,
+                         stderr=subprocess.PIPE)
+    out,err = p.communicate()
+    res = p.wait()
+    return CompileInfo(out,err,res)
+
+def main():
+    import os, sys
+
+    args = sys.argv[1:]
+    driverA = os.getenv('DRIVER_A') or 'gcc'
+    driverB = os.getenv('DRIVER_B') or 'clang'
+
+    infoA = captureDriverInfo(driverA, args)
+    infoB = captureDriverInfo(driverB, args)
+
+    differ = False
+
+    # Compare stdout.
+    if infoA.stdout != infoB.stdout:
+        print '-- STDOUT DIFFERS -'
+        print 'A OUTPUT: ',infoA.stdout
+        print 'B OUTPUT: ',infoB.stdout
+        print
+
+        diff = ZipperDiff(infoA.stdout.split('\n'),
+                          infoB.stdout.split('\n'))
+        for i,(aElt,bElt) in enumerate(diff.getDiffs()):
+            if aElt is None:
+                print 'A missing: %s' % bElt
+            elif bElt is None:
+                print 'B missing: %s' % aElt
+            else:
+                print 'mismatch: A: %s' % aElt
+                print '          B: %s' % bElt
+
+        differ = True
+
+    # Compare stderr.
+    if infoA.stderr != infoB.stderr:
+        print '-- STDERR DIFFERS -'
+        print 'A STDERR: ',infoA.stderr
+        print 'B STDERR: ',infoB.stderr
+        print
+
+        diff = ZipperDiff(infoA.stderr.split('\n'),
+                          infoB.stderr.split('\n'))
+        for i,(aElt,bElt) in enumerate(diff.getDiffs()):
+            if aElt is None:
+                print 'A missing: %s' % bElt
+            elif bElt is None:
+                print 'B missing: %s' % aElt
+            else:
+                print 'mismatch: A: %s' % aElt
+                print '          B: %s' % bElt
+
+        differ = True
+
+    # Compare commands.
+    for i,(a,b) in enumerate(map(None, infoA.commands, infoB.commands)):
+        if a is None:
+            print 'A MISSING:',' '.join(b)
+            differ = True
+            continue
+        elif b is None:
+            print 'B MISSING:',' '.join(a)
+            differ = True
+            continue
+
+        diff = DriverZipperDiff(a,b)
+        diffs = list(diff.getDiffs())
+        if diffs:
+            print '-- COMMAND %d DIFFERS -' % i
+            print 'A COMMAND:',' '.join(a)
+            print 'B COMMAND:',' '.join(b)
+            print
+            for i,(aElt,bElt) in enumerate(diffs):
+                if aElt is None:
+                    print 'A missing: %s' % bElt
+                elif bElt is None:
+                    print 'B missing: %s' % aElt
+                else:
+                    print 'mismatch: A: %s' % aElt
+                    print '          B: %s' % bElt
+            differ = True
+    
+    # Compare result codes.
+    if infoA.exitCode != infoB.exitCode:
+        print '-- EXIT CODES DIFFER -'
+        print 'A: ',infoA.exitCode
+        print 'B: ',infoB.exitCode
+        differ = True
+
+    if differ:
+        sys.exit(1)
+
+if __name__ == '__main__':
+    main()