Fix isBeforeInTranslationUnit to not abort on macros defined in cmdline.

[ygribov]

Summary

This patch fixes assert "Unsortable locations found" when calling

PathDiagnosticLocation(SM.getSpellingLoc(E->getLocStart()), SM);

on an expression which comes from cmdline (i.e. macro defined with -D). Such expressions come from a special scratch buffer and thus trigger assert when passed to isBeforeInTranslationUnit.

Unfortunately this only reproduces on a local branch so I can not provide a minimal testcase. I hope the fix is self-evident though.

[ygribov]

Forgot to mention - no regressions in make check-all.

[ygribov]

Ping.

[ygribov]

Ping.

[ygribov]

Ping.

[joerg]

I'd prefer if the functional and cosmetic part of the patch was separated. The change looks reasonable otherwise.

cfe/trunk/lib/Basic/SourceManager.cpp

if (LOffs.first == ROffs.first) {
     return IsBeforeInTUCache.getCachedResult(LOffs.second, ROffs.second);
   }
 
   // If we arrived here, the location is either in a built-ins buffer or
   // associated with global inline asm. PR5662 and PR22576 are examples.
 
   // Clear the lookup cache, it depends on a common location.
   IsBeforeInTUCache.clear();
-  llvm::MemoryBuffer *LBuf = getBuffer(LOffs.first);
-  llvm::MemoryBuffer *RBuf = getBuffer(ROffs.first);
-  bool LIsBuiltins = strcmp("<built-in>", LBuf->getBufferIdentifier()) == 0;
-  bool RIsBuiltins = strcmp("<built-in>", RBuf->getBufferIdentifier()) == 0;
+  const char *LB = getBuffer(LOffs.first)->getBufferIdentifier();
+  const char *RB = getBuffer(ROffs.first)->getBufferIdentifier();
+  bool LIsBuiltins = strcmp("<built-in>", LB) == 0;
+  bool RIsBuiltins = strcmp("<built-in>", RB) == 0;
   // Sort built-in before non-built-in.
   if (LIsBuiltins || RIsBuiltins) {
     if (LIsBuiltins != RIsBuiltins)
       return LIsBuiltins;
     // Both are in built-in buffers, but from different files. We just claim that
     // lower IDs come first.
     return LOffs.first < ROffs.first;
   }
-  bool LIsAsm = strcmp("<inline asm>", LBuf->getBufferIdentifier()) == 0;
-  bool RIsAsm = strcmp("<inline asm>", RBuf->getBufferIdentifier()) == 0;
+  bool LIsAsm = strcmp("<inline asm>", LB) == 0;
+  bool RIsAsm = strcmp("<inline asm>", RB) == 0;
   // Sort assembler after built-ins, but before the rest.
   if (LIsAsm || RIsAsm) {
     if (LIsAsm != RIsAsm)
       return RIsAsm;
     assert(LOffs.first == ROffs.first);
     return false;
   }
   llvm_unreachable("Unsortable locations found");