From: David Majnemer <david.majnemer@gmail.com>
Date: Wed, 28 Jan 2015 05:48:06 +0000 (+0000)
Subject: Sema: Ensure that __c11_atomic_fetch_add has a pointer to complete type
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=18a541723125a193231dbb1b9fb2250c0577bf8d;p=clang

Sema: Ensure that __c11_atomic_fetch_add has a pointer to complete type

Pointer arithmetic is only makes sense if the pointee type is complete.

This fixes PR22361.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@227295 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index d1a27569da..cfa61119c8 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -1404,6 +1404,11 @@ ExprResult Sema::SemaAtomicOpsOverloaded(ExprResult TheCallResult,
         << IsC11 << Ptr->getType() << Ptr->getSourceRange();
       return ExprError();
     }
+    if (IsC11 && ValType->isPointerType() &&
+        RequireCompleteType(Ptr->getLocStart(), ValType->getPointeeType(),
+                            diag::err_incomplete_type)) {
+      return ExprError();
+    }
   } else if (IsN && !ValType->isIntegerType() && !ValType->isPointerType()) {
     // For __atomic_*_n operations, the value type must be a scalar integral or
     // pointer type which is 1, 2, 4, 8 or 16 bytes in length.
diff --git a/test/Sema/atomic-ops.c b/test/Sema/atomic-ops.c
index e21c3fd58e..71eaaa8b7a 100644
--- a/test/Sema/atomic-ops.c
+++ b/test/Sema/atomic-ops.c
@@ -49,7 +49,7 @@ char i8;
 short i16;
 int i32;
 int __attribute__((vector_size(8))) i64;
-struct Incomplete *incomplete;
+struct Incomplete *incomplete; // expected-note {{forward declaration of 'struct Incomplete'}}
 
 _Static_assert(__atomic_is_lock_free(1, &i8), "");
 _Static_assert(__atomic_is_lock_free(1, &i64), "");
@@ -268,6 +268,10 @@ void memory_checks(_Atomic(int) *Ap, int *p, int val) {
   (void)__c11_atomic_fetch_add(Ap, 1, memory_order_acq_rel);
   (void)__c11_atomic_fetch_add(Ap, 1, memory_order_seq_cst);
 
+  (void)__c11_atomic_fetch_add(
+      (struct Incomplete * _Atomic *)0, // expected-error {{incomplete type 'struct Incomplete'}}
+      1, memory_order_seq_cst);
+
   (void)__c11_atomic_init(Ap, val);
   (void)__c11_atomic_init(Ap, val);
   (void)__c11_atomic_init(Ap, val);