[cfe-commits] r71942 - in /cfe/trunk: lib/Sema/SemaExpr.cpp test/Sema/va_arg_x86_32.c

[Eli Friedman]

Author: efriedma
Date: Sat May 16 07:46:54 2009
New Revision: 71942

URL: http://llvm.org/viewvc/llvm-project?rev=71942&view=rev
Log:
Add stricter checking for va_arg.


Added:
    cfe/trunk/test/Sema/va_arg_x86_32.c
Modified:
    cfe/trunk/lib/Sema/SemaExpr.cpp

Modified: cfe/trunk/lib/Sema/SemaExpr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaExpr.cpp?rev=71942&r1=71941&r2=71942&view=diff

==============================================================================
--- cfe/trunk/lib/Sema/SemaExpr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaExpr.cpp Sat May 16 07:46:54 2009
@@ -5208,15 +5208,21 @@
 
   // Get the va_list type
   QualType VaListType = Context.getBuiltinVaListType();
-  // Deal with implicit array decay; for example, on x86-64,
-  // va_list is an array, but it's supposed to decay to
-  // a pointer for va_arg.
-  if (VaListType->isArrayType())
+  if (VaListType->isArrayType()) {
+    // Deal with implicit array decay; for example, on x86-64,
+    // va_list is an array, but it's supposed to decay to
+    // a pointer for va_arg.
     VaListType = Context.getArrayDecayedType(VaListType);
-  // Make sure the input expression also decays appropriately.
-  UsualUnaryConversions(E);
+    // Make sure the input expression also decays appropriately.
+    UsualUnaryConversions(E);
+  } else {
+    // Otherwise, the va_list argument must be an l-value because
+    // it is modified by va_arg.
+    if (CheckForModifiableLvalue(E, BuiltinLoc, *this))
+      return ExprError();
+  }
 
-  if (CheckAssignmentConstraints(VaListType, E->getType()) != Compatible) {
+  if (!Context.hasSameType(VaListType, E->getType())) {
     return ExprError(Diag(E->getLocStart(),
                          diag::err_first_argument_to_va_arg_not_of_type_va_list)
       << OrigExpr->getType() << E->getSourceRange());

Added: cfe/trunk/test/Sema/va_arg_x86_32.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/Sema/va_arg_x86_32.c?rev=71942&view=auto

==============================================================================
--- cfe/trunk/test/Sema/va_arg_x86_32.c (added)
+++ cfe/trunk/test/Sema/va_arg_x86_32.c Sat May 16 07:46:54 2009
@@ -0,0 +1,6 @@
+// RUN: clang-cc -fsyntax-only -verify -triple=i686-pc-linux-gnu %s
+
+int a() {
+  __builtin_va_arg((char*)0, int); // expected-error {{expression is not assignable}}
+  __builtin_va_arg((void*){0}, int); // expected-error {{first argument to 'va_arg' is of type 'void *'}}
+}