Make DartVM build with clang.

runtime/third_party/jscre/pcre_exec.cpp

 /* This is JavaScriptCore's variant of the PCRE library. While this library
 started out as a copy of PCRE, many of the features of PCRE have been
 removed. This library now supports only the regular expression features
 required by the JavaScript language specification, and has only the functions
 needed by JavaScriptCore and the rest of WebKit.
 
                  Originally written by Philip Hazel
            Copyright (c) 1997-2006 University of Cambridge
     Copyright (C) 2002, 2004, 2006, 2007 Apple Inc. All rights reserved.
     Copyright (C) 2007 Eric Seidel <eric@webkit.org>
@@ skipping 1133 matching lines @@
                 
             REPEATCHAR:
                 
                 stack.currentFrame->locals.length = 1;
                 getUTF8CharAndIncrementLength(stack.currentFrame->locals.fc, stack.currentFrame->args.instructionPtr, stack.currentFrame->locals.length);
                 if (min * (stack.currentFrame->locals.fc > 0xFFFF ? 2 : 1) > md.endSubject - stack.currentFrame->args.subjectPtr)
                     RRETURN_NO_MATCH;
                 stack.currentFrame->args.instructionPtr += stack.currentFrame->locals.length;
                 
                 if (stack.currentFrame->locals.fc <= 0xFFFF) {
-                    int othercase = md.ignoreCase ? kjs_pcre_ucp_othercase(stack.currentFrame->locals.fc) : -1;
+                    int othercase;
+                    othercase = md.ignoreCase ? kjs_pcre_ucp_othercase(stack.currentFrame->locals.fc) : -1;

[Ivan Posva, 2011/10/31 14:00:09]

Not sure what you changed here. And why it makes clang happier this way.

[Anton Muhin, 2011/10/31 18:46:01]

Clang complains:

<quotation>
/Users/antonm/Google/dartium/src/dart/runtime/third_party/jscre/pcre_exec.cpp:1017:25:
error: indirect goto might cross protected scopes
                        RRETURN_NO_MATCH;
                        ^
/Users/antonm/Google/dartium/src/dart/runtime/third_party/jscre/pcre_exec.cpp:274:48:
note: expanded from:
#define RRETURN_NO_MATCH do { isMatch = false; RRETURN; } while (0)
                                               ^
/Users/antonm/Google/dartium/src/dart/runtime/third_party/jscre/pcre_exec.cpp:272:17:
note: expanded from:
#define RRETURN goto RRETURN_LABEL
                ^
/Users/antonm/Google/dartium/src/dart/runtime/third_party/jscre/pcre_exec.cpp:1168:29:
note: possible target of indirect goto
                            RECURSIVE_MATCH(28,
stack.currentFrame->args.instructionPtr, stack.currentFrame->args.bracketChain);
                            ^
/Users/antonm/Google/dartium/src/dart/runtime/third_party/jscre/pcre_exec.cpp:262:9:
note: expanded from:
        RECURSIVE_MATCH_COMMON(num) \
        ^
/Users/antonm/Google/dartium/src/dart/runtime/third_party/jscre/pcre_exec.cpp:256:13:
note: expanded from:
    RRETURN_##num: \
            ^
<scratch space>:159:1: note: expanded from:
RRETURN_28
^
/Users/antonm/Google/dartium/src/dart/runtime/third_party/jscre/pcre_exec.cpp:1154:25:
note: jump bypasses variable initialization
                    int othercase = md.ignoreCase ?
kjs_pcre_ucp_othercase(stack.currentFrame->locals.fc) : -1;
</quotation>

I suspect it's 6.7/3:

<quotation>
3 It is possible to transfer into a block, but not in a way that bypasses
declarations with initialization. A program that jumps
77)
from a point where a local variable with automatic storage duration is not in
scope to a
point where it is in scope is ill-formed unless the variable has POD type (3.9)
and is declared without an
initializer (8.5)
</quotation>

                     
                     for (int i = 1; i <= min; i++) {
                         if (*stack.currentFrame->args.subjectPtr != stack.currentFrame->locals.fc && *stack.currentFrame->args.subjectPtr != othercase)
                             RRETURN_NO_MATCH;
                         ++stack.currentFrame->args.subjectPtr;
                     }
                     
                     if (min == stack.currentFrame->locals.max)
                         NEXT_OPCODE;
                     
@@ skipping 911 matching lines @@
     if (using_temporary_offsets) {
         DPRINTF(("Freeing temporary memory\n"));
         delete [] matchBlock.offsetVector;
     }
     
     DPRINTF((">>>> returning PCRE_ERROR_NOMATCH\n"));
     return JSRegExpErrorNoMatch;
 }
 
 } }  // namespace dart::jscre