Don't try to call getFileCharacteristic if the function declaration has an invalid source location (as is the case for the global allocation functions.

llvm-svn: 72671

clang/lib/CodeGen/Mangle.cpp

@@ -94,7 +94,8 @@ bool CXXNameMangler::mangleFunctionDecl(const FunctionDecl *FD) {
              // "main" is not mangled in C++
              FD->isMain() ||
              // No mangling in an "implicit extern C" header. 
-             Context.getSourceManager().getFileCharacteristic(FD->getLocation())
+             (FD->getLocation().isValid() && 
+              Context.getSourceManager().getFileCharacteristic(FD->getLocation()))
                == SrcMgr::C_ExternCSystem ||
              // No name mangling in a C linkage specification.
              isInCLinkageSpecification(FD))