From 17fa2487df460a27d35c53d5a5620119e36ae67b Mon Sep 17 00:00:00 2001 From: WenHan Gu Date: Mon, 17 Jun 2013 20:47:59 +0800 Subject: [PATCH] [Bugfix] De-reference pointer after null check. Not all FunctionDecl has this valid pointer. For example, functions in builtin lists doesn't has valid one. if we has only one line: "void vfprintf() {}" in source, we will get Segmentation fault since this null-pointer dereference. test.c:1:6: warning: incompatible redeclaration of library function 'vfprintf' [-Wincompatible-library-redeclaration] void vfprintf(void) {} ^ test.c:1:6: note: 'vfprintf' is a builtin with type 'int ()' 0 clang 0x0000000002454ef2 llvm::sys::PrintStackTrace(_IO_FILE*) + 34 ... --- lib/Sema/SemaDecl.cpp | 15 ++++++++------- 1 files changed, 8 insertions(+), 7 deletions(-) diff --git a/lib/Sema/SemaDecl.cpp b/lib/Sema/SemaDecl.cpp index 92e0042..fd6747e 100644 --- a/lib/Sema/SemaDecl.cpp +++ b/lib/Sema/SemaDecl.cpp @@ -8708,13 +8708,14 @@ Decl *Sema::ActOnStartOfFunctionDef(Scope *FnBodyScope, Decl *D) { if (PossibleZeroParamPrototype) { // We found a declaration that is not a prototype, // but that could be a zero-parameter prototype - TypeSourceInfo* TI = PossibleZeroParamPrototype->getTypeSourceInfo(); - TypeLoc TL = TI->getTypeLoc(); - if (FunctionNoProtoTypeLoc FTL = TL.getAs()) - Diag(PossibleZeroParamPrototype->getLocation(), - diag::note_declaration_not_a_prototype) - << PossibleZeroParamPrototype - << FixItHint::CreateInsertion(FTL.getRParenLoc(), "void"); + if (TypeSourceInfo* TI = PossibleZeroParamPrototype->getTypeSourceInfo()) { + TypeLoc TL = TI->getTypeLoc(); + if (FunctionNoProtoTypeLoc FTL = TL.getAs()) + Diag(PossibleZeroParamPrototype->getLocation(), + diag::note_declaration_not_a_prototype) + << PossibleZeroParamPrototype + << FixItHint::CreateInsertion(FTL.getRParenLoc(), "void"); + } } } -- 1.7.0.4