r218258 - Fix evatuated value of __builtin_object_size according to its

[Fariborz Jahanian]

Author: fjahanian
Date: Mon Sep 22 12:11:59 2014
New Revision: 218258

URL: http://llvm.org/viewvc/llvm-project?rev=218258&view=rev
Log:
Fix evatuated value of __builtin_object_size according to its
'type'  argument when it cannot be determined which objects ptr 
points to at compile time. rdar://18334276

Modified:
    cfe/trunk/lib/AST/ExprConstant.cpp
    cfe/trunk/test/Sema/builtin-object-size.c

Modified: cfe/trunk/lib/AST/ExprConstant.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/ExprConstant.cpp?rev=218258&r1=218257&r2=218258&view=diff
==============================================================================
--- cfe/trunk/lib/AST/ExprConstant.cpp (original)
+++ cfe/trunk/lib/AST/ExprConstant.cpp Mon Sep 22 12:11:59 2014
@@ -6052,8 +6052,20 @@ bool IntExprEvaluator::TryEvaluateBuilti
       return false;
   }
 
-  // If we can prove the base is null, lower to zero now.
-  if (!Base.getLValueBase()) return Success(0, E);
+  if (!Base.getLValueBase()) {
+    // It is not possible to determine which objects ptr points to at compile time,
+    // __builtin_object_size should return (size_t) -1 for type 0 or 1
+    // and (size_t) 0 for type 2 or 3.
+    llvm::APSInt TypeIntVaue;
+    const Expr *ExprType = E->getArg(1);
+    if (!ExprType->EvaluateAsInt(TypeIntVaue, Info.Ctx))
+      return false;
+    if (TypeIntVaue == 0 || TypeIntVaue == 1)
+      return Success(-1, E);
+    if (TypeIntVaue == 2 || TypeIntVaue == 3)
+      return Success(0, E);
+    return Error(E);
+  }
 
   QualType T = GetObjectType(Base.getLValueBase());
   if (T.isNull() ||

Modified: cfe/trunk/test/Sema/builtin-object-size.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/builtin-object-size.c?rev=218258&r1=218257&r2=218258&view=diff
==============================================================================
--- cfe/trunk/test/Sema/builtin-object-size.c (original)
+++ cfe/trunk/test/Sema/builtin-object-size.c Mon Sep 22 12:11:59 2014
@@ -26,3 +26,20 @@ void f4(const char *fmt, ...) {
  __builtin___vsnprintf_chk (0, 42, 0, 11, fmt, args); // expected-warning {{'__builtin___vsnprintf_chk' will always overflow destination buffer}}
 }
 
+// rdar://18334276
+typedef unsigned long size_t;
+void * memcset(void *restrict dst, int src, size_t n);
+void * memcpy(void *restrict dst, const void *restrict src, size_t n);
+
+#define memset(dest, src, len) __builtin___memset_chk(dest, src, len, __builtin_object_size(dest, 0))
+#define memcpy(dest, src, len) __builtin___memcpy_chk(dest, src, len, __builtin_object_size(dest, 0))
+#define memcpy1(dest, src, len) __builtin___memcpy_chk(dest, src, len, __builtin_object_size(dest, 4))
+#define NULL ((void *)0)
+
+void f5(void)
+{
+  char buf[10];
+  memset((void *)0x100000000ULL, 0, 0x1000);
+  memcpy((char *)NULL + 0x10000, buf, 0x10);
+  memcpy1((char *)NULL + 0x10000, buf, 0x10); // expected-error {{argument should be a value from 0 to 3}}
+}