Support for C1x _Atomic specifier (see testcase). This is primarily being committed at the moment to help support C++0x <atomic>, but it should be a solid base for implementing the full specification of C1x _Atomic.

Thanks to Jeffrey Yasskin for the thorough review!



git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@141330 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 47 insertions, 0 deletions

diff --git a/lib/Sema/SemaType.cpp b/lib/Sema/SemaType.cpp
index 4a865bf235..995d767e2b 100644
--- a/lib/Sema/SemaType.cpp
+++ b/lib/Sema/SemaType.cpp
@@ -856,6 +856,16 @@ static QualType ConvertDeclSpecToType(TypeProcessingState &state) {
     Result = Context.UnknownAnyTy;
     break;
 
+  case DeclSpec::TST_atomic:
+    Result = S.GetTypeFromParser(DS.getRepAsType());
+    assert(!Result.isNull() && "Didn't get a type for _Atomic?");
+    Result = S.BuildAtomicType(Result, DS.getTypeSpecTypeLoc());
+    if (Result.isNull()) {
+      Result = Context.IntTy;
+      declarator.setInvalidType(true);
+    }
+    break; 
+
   case DeclSpec::TST_error:
     Result = Context.IntTy;
     declarator.setInvalidType(true);
@@ -2872,6 +2882,10 @@ namespace {
     void VisitTagTypeLoc(TagTypeLoc TL) {
       TL.setNameLoc(DS.getTypeSpecTypeNameLoc());
     }
+    void VisitAtomicTypeLoc(AtomicTypeLoc TL) {
+      TL.setKWLoc(DS.getTypeSpecTypeLoc());
+      TL.setParensRange(DS.getTypeofParensRange());
+    }
 
     void VisitTypeLoc(TypeLoc TL) {
       // FIXME: add other typespec types and change this to an assert.
@@ -4183,3 +4197,36 @@ QualType Sema::BuildUnaryTransformType(QualType BaseType,
   }
   llvm_unreachable("unknown unary transform type");
 }
+
+QualType Sema::BuildAtomicType(QualType T, SourceLocation Loc) {
+  if (!T->isDependentType()) {
+    int DisallowedKind = -1;
+    if (T->isIncompleteType())
+      // FIXME: It isn't entirely clear whether incomplete atomic types
+      // are allowed or not; for simplicity, ban them for the moment.
+      DisallowedKind = 0;
+    else if (T->isArrayType())
+      DisallowedKind = 1;
+    else if (T->isFunctionType())
+      DisallowedKind = 2;
+    else if (T->isReferenceType())
+      DisallowedKind = 3;
+    else if (T->isAtomicType())
+      DisallowedKind = 4;
+    else if (T.hasQualifiers())
+      DisallowedKind = 5;
+    else if (!T.isTriviallyCopyableType(Context))
+      // Some other non-trivially-copyable type (probably a C++ class)
+      DisallowedKind = 6;
+
+    if (DisallowedKind != -1) {
+      Diag(Loc, diag::err_atomic_specifier_bad_type) << DisallowedKind << T;
+      return QualType();
+    }
+
+    // FIXME: Do we need any handling for ARC here?
+  }
+
+  // Build the pointer type.
+  return Context.getAtomicType(T);
+}