[PATCH] D18698: [C11] PR24451: Allow restrict _Atomic pointers

[Denis Zobnin via cfe-commits]

d.zobnin.bugzilla created this revision.
d.zobnin.bugzilla added a reviewer: rsmith.
d.zobnin.bugzilla added a subscriber: cfe-commits.

Treat _Atomic pointers as pointer types (check value type of AtomicType) in case of handling the "restrict" qualifier. Accept such code (so does GCC):

int * restrict _Atomic p;

http://reviews.llvm.org/D18698

Files:
  lib/Sema/SemaType.cpp
  test/Misc/ast-dump-restrict-atomic.c

Index: lib/Sema/SemaType.cpp
===================================================================
--- lib/Sema/SemaType.cpp
+++ lib/Sema/SemaType.cpp
@@ -1663,12 +1663,18 @@
   if (T.isNull())
     return QualType();
 
+  QualType OriginalType = T;
+
   // Enforce C99 6.7.3p2: "Types other than pointer types derived from
   // object or incomplete types shall not be restrict-qualified."
   if (Qs.hasRestrict()) {
     unsigned DiagID = 0;
     QualType ProblemTy;
 
+    // Handle code like "int * _Atomic restrict p".
+    if (const AtomicType *AtomicT = T->getAs<AtomicType>())
+      T = AtomicT->getValueType();
+
     if (T->isAnyPointerType() || T->isReferenceType() ||
         T->isMemberPointerType()) {
       QualType EltTy;
@@ -1696,7 +1702,7 @@
     }
   }
 
-  return Context.getQualifiedType(T, Qs);
+  return Context.getQualifiedType(OriginalType, Qs);
 }
 
 QualType Sema::BuildQualifiedType(QualType T, SourceLocation Loc,
Index: test/Misc/ast-dump-restrict-atomic.c
===================================================================
--- test/Misc/ast-dump-restrict-atomic.c
+++ test/Misc/ast-dump-restrict-atomic.c
@@ -0,0 +1,13 @@
+// RUN: %clang_cc1 -std=c11 -ast-dump %s | FileCheck %s
+// RUN: %clang_cc1 -std=c11 -verify %s
+// expected-no-diagnostics
+
+int * _Atomic restrict a;
+int * restrict _Atomic b;
+int _Atomic * restrict c;
+volatile _Atomic int * restrict _Atomic const * restrict d;
+
+// CHECK: a '__restrict _Atomic(int *)'
+// CHECK: b '__restrict _Atomic(int *)'
+// CHECK: c '_Atomic(int) *__restrict'
+// CHECK: d 'const __restrict _Atomic(volatile _Atomic(int) *) *__restrict'


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