When a function takes a variable number of pointer arguments, with a zero
pointer marking the end of the list, the zero *must* be cast to the pointer
type.  An un-cast zero is a 32-bit int, and at least on x86_64, gcc will
not extend the zero to 64 bits, thus allowing the upper 32 bits to be
random junk.

The new END_WITH_NULL macro may be used to annotate a such a function
so that GCC (version 4 or newer) will detect the use of un-casted zero
at compile time.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@23888 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/AsmParser/llvmAsmParser.y b/lib/AsmParser/llvmAsmParser.y
index e8ca9c0..c0b7d63 100644
--- a/lib/AsmParser/llvmAsmParser.y
+++ b/lib/AsmParser/llvmAsmParser.y
@@ -766,7 +766,7 @@
       const Type* ArgTy = F->getFunctionType()->getReturnType();
       const Type* ArgTyPtr = PointerType::get(ArgTy);
       Function* NF = Result->getOrInsertFunction("llvm.va_start", 
-                                                 RetTy, ArgTyPtr, 0);
+                                                 RetTy, ArgTyPtr, (Type *)0);
 
       while (!F->use_empty()) {
         CallInst* CI = cast<CallInst>(F->use_back());
@@ -791,7 +791,7 @@
       const Type* ArgTy = F->getFunctionType()->getParamType(0);
       const Type* ArgTyPtr = PointerType::get(ArgTy);
       Function* NF = Result->getOrInsertFunction("llvm.va_end", 
-                                                 RetTy, ArgTyPtr, 0);
+                                                 RetTy, ArgTyPtr, (Type *)0);
 
       while (!F->use_empty()) {
         CallInst* CI = cast<CallInst>(F->use_back());
@@ -818,7 +818,8 @@
       const Type* ArgTy = F->getFunctionType()->getReturnType();
       const Type* ArgTyPtr = PointerType::get(ArgTy);
       Function* NF = Result->getOrInsertFunction("llvm.va_copy", 
-                                                 RetTy, ArgTyPtr, ArgTyPtr, 0);
+                                                 RetTy, ArgTyPtr, ArgTyPtr,
+                                                 (Type *)0);
 
       while (!F->use_empty()) {
         CallInst* CI = cast<CallInst>(F->use_back());
@@ -2074,7 +2075,7 @@
     ObsoleteVarArgs = true;
     const Type* ArgTy = $2->getType();
     Function* NF = CurModule.CurrentModule->
-      getOrInsertFunction("llvm.va_copy", ArgTy, ArgTy, 0);
+      getOrInsertFunction("llvm.va_copy", ArgTy, ArgTy, (Type *)0);
 
     //b = vaarg a, t -> 
     //foo = alloca 1 of t
@@ -2093,7 +2094,7 @@
     ObsoleteVarArgs = true;
     const Type* ArgTy = $2->getType();
     Function* NF = CurModule.CurrentModule->
-      getOrInsertFunction("llvm.va_copy", ArgTy, ArgTy, 0);
+      getOrInsertFunction("llvm.va_copy", ArgTy, ArgTy, (Type *)0);
 
     //b = vanext a, t ->
     //foo = alloca 1 of t