Fix a nasty bug where inside StringLiteralParser:

1. We would assume that the length of the string literal token was at least 2
2. We would allocate a buffer with size length-2

And when the stars aligned (one of which would be an invalid source location due to stale PCH)
The length would be 0 and we would try to allocate a 4GB buffer.

Add checks for this corner case and a bunch of asserts.
(We really really should have had an assert for 1.).

Note that there's no test case since I couldn't get one (it was major PITA to reproduce),
maybe later.

llvm-svn: 131492

1 files changed, 5 insertions, 3 deletions

diff --git a/clang/include/clang/Lex/LiteralSupport.h b/clang/include/clang/Lex/LiteralSupport.h
index dcaf4457cfa..ec3d9c58d67 100644
--- a/clang/include/clang/Lex/LiteralSupport.h
+++ b/clang/include/clang/Lex/LiteralSupport.h
@@ -156,7 +156,9 @@ public:
   StringLiteralParser(const Token *StringToks, unsigned NumStringToks,
                       const SourceManager &sm, const LangOptions &features,
                       const TargetInfo &target, Diagnostic *diags = 0)
-    : SM(sm), Features(features), Target(target), Diags(diags) {
+    : SM(sm), Features(features), Target(target), Diags(diags),
+      MaxTokenLength(0), SizeBound(0), wchar_tByteWidth(0),
+      ResultPtr(ResultBuf.data()), hadError(false), AnyWide(false), Pascal(false) {
     init(StringToks, NumStringToks);
   }
     
@@ -165,8 +167,8 @@ public:
   bool AnyWide;
   bool Pascal;
 
-  const char *GetString() { return &ResultBuf[0]; }
-  unsigned GetStringLength() const { return ResultPtr-&ResultBuf[0]; }
+  const char *GetString() { return ResultBuf.data(); }
+  unsigned GetStringLength() const { return ResultPtr-ResultBuf.data(); }
 
   unsigned GetNumStringChars() const {
     if (AnyWide)