Disallow pointers to const in __sync_fetch_and_xxx.

Diagnoses code like:

void f(const int *ptr) {
  __sync_fetch_and_add(ptr, 1);
}

which matches the behavior of GCC and ICC.

llvm-svn: 331598

diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index 053f2fc..03988a1 100644 (file)
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -7094,6 +7094,8 @@ def err_atomic_builtin_must_be_pointer : Error<
 def err_atomic_builtin_must_be_pointer_intptr : Error<
   "address argument to atomic builtin must be a pointer to integer or pointer"
   " (%0 invalid)">;
+def err_atomic_builtin_cannot_be_const : Error<
+  "address argument to atomic builtin cannot be const-qualified (%0 invalid)">;
 def err_atomic_builtin_must_be_pointer_intfltptr : Error<
   "address argument to atomic builtin must be a pointer to integer,"
   " floating-point or pointer (%0 invalid)">;

diff --git a/clang/lib/Sema/SemaChecking.cpp b/clang/lib/Sema/SemaChecking.cpp
index b52ff97..8cc8330 100644 (file)
--- a/clang/lib/Sema/SemaChecking.cpp
+++ b/clang/lib/Sema/SemaChecking.cpp
@@ -3445,6 +3445,12 @@ Sema::SemaBuiltinAtomicOverloaded(ExprResult TheCallResult) {
     return ExprError();
   }
 
+  if (ValType.isConstQualified()) {
+    Diag(DRE->getLocStart(), diag::err_atomic_builtin_cannot_be_const)
+        << FirstArg->getType() << FirstArg->getSourceRange();
+    return ExprError();
+  }
+
   switch (ValType.getObjCLifetime()) {
   case Qualifiers::OCL_None:
   case Qualifiers::OCL_ExplicitNone:

diff --git a/clang/test/Sema/builtins.c b/clang/test/Sema/builtins.c
index 0e2925e..7e99999 100644 (file)
--- a/clang/test/Sema/builtins.c
+++ b/clang/test/Sema/builtins.c
@@ -248,3 +248,8 @@ char * Test20(char *p, const char *in, unsigned n)
 
     return buf;
 }
+
+void test21(const int *ptr) {
+  __sync_fetch_and_add(ptr, 1); // expected-error{{address argument to atomic builtin cannot be const-qualified ('const int *' invalid)}}
+  __atomic_fetch_add(ptr, 1, 0);  // expected-error {{address argument to atomic operation must be a pointer to non-const type ('const int *' invalid)}}
+}