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

1 files changed, 4 insertions, 2 deletions

diff --git a/lib/Bytecode/Reader/Reader.cpp b/lib/Bytecode/Reader/Reader.cpp
index ba9c6ca97f..daf7577cf0 100644
--- a/lib/Bytecode/Reader/Reader.cpp
+++ b/lib/Bytecode/Reader/Reader.cpp
@@ -680,7 +680,8 @@ void BytecodeReader::ParseInstruction(std::vector<unsigned> &Oprnds,
     break;
   case 32: { //VANext_old
     const Type* ArgTy = getValue(iType, Oprnds[0])->getType();
-    Function* NF = TheModule->getOrInsertFunction("llvm.va_copy", ArgTy, ArgTy, 0);
+    Function* NF = TheModule->getOrInsertFunction("llvm.va_copy", ArgTy, ArgTy,
+                                                  (Type *)0);
 
     //b = vanext a, t ->
     //foo = alloca 1 of t
@@ -700,7 +701,8 @@ void BytecodeReader::ParseInstruction(std::vector<unsigned> &Oprnds,
   }
   case 33: { //VAArg_old
     const Type* ArgTy = getValue(iType, Oprnds[0])->getType();
-    Function* NF = TheModule->getOrInsertFunction("llvm.va_copy", ArgTy, ArgTy, 0);
+    Function* NF = TheModule->getOrInsertFunction("llvm.va_copy", ArgTy, ArgTy,
+                                                  (Type *)0);
 
     //b = vaarg a, t ->
     //foo = alloca 1 of t