r195323 - Add new attribute 'objc_suppress_protocol' to suppress protocol conformance for a class.
Ted Kremenek
kremenek at apple.com
Wed Nov 20 23:20:42 PST 2013
Author: kremenek
Date: Thu Nov 21 01:20:42 2013
New Revision: 195323
URL: http://llvm.org/viewvc/llvm-project?rev=195323&view=rev
Log:
Add new attribute 'objc_suppress_protocol' to suppress protocol conformance for a class.
The idea is to allow a class to stipulate that its methods (and those
of its parents) cannot be used for protocol conformance in a subclass.
A subclass is then explicitly required to re-implement those methods
of they are present in the class marked with this attribute.
Currently the attribute can only be applied to an @interface, and
not a category or class extension. This is by design. Unlike
protocol conformance, where a category can add explicit conformance
of a protocol to class, this anti-conformance really needs to be
observed uniformly by all clients of the class. That's because
the absence of the attribute implies more permissive checking of
protocol conformance.
This unfortunately required changing method lookup in ObjCInterfaceDecl
to take an optional protocol parameter. This should not slow down
method lookup in most cases, and is just used for protocol conformance.
Added:
cfe/trunk/test/SemaObjC/protocols-suppress-conformance.m
Modified:
cfe/trunk/include/clang/AST/DeclObjC.h
cfe/trunk/include/clang/Basic/Attr.td
cfe/trunk/lib/AST/DeclObjC.cpp
cfe/trunk/lib/Sema/SemaDeclAttr.cpp
cfe/trunk/lib/Sema/SemaDeclObjC.cpp
Modified: cfe/trunk/include/clang/AST/DeclObjC.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/AST/DeclObjC.h?rev=195323&r1=195322&r2=195323&view=diff
==============================================================================
--- cfe/trunk/include/clang/AST/DeclObjC.h (original)
+++ cfe/trunk/include/clang/AST/DeclObjC.h Thu Nov 21 01:20:42 2013
@@ -1142,14 +1142,17 @@ public:
// found, we search referenced protocols and class categories.
ObjCMethodDecl *lookupMethod(Selector Sel, bool isInstance,
bool shallowCategoryLookup= false,
- const ObjCCategoryDecl *C= 0) const;
+ const ObjCCategoryDecl *C = 0,
+ const ObjCProtocolDecl *P = 0) const;
ObjCMethodDecl *lookupInstanceMethod(Selector Sel,
- bool shallowCategoryLookup = false) const {
- return lookupMethod(Sel, true/*isInstance*/, shallowCategoryLookup);
+ bool shallowCategoryLookup = false,
+ ObjCProtocolDecl *P = 0) const {
+ return lookupMethod(Sel, true/*isInstance*/, shallowCategoryLookup, 0, P);
}
ObjCMethodDecl *lookupClassMethod(Selector Sel,
- bool shallowCategoryLookup = false) const {
- return lookupMethod(Sel, false/*isInstance*/, shallowCategoryLookup);
+ bool shallowCategoryLookup = false,
+ ObjCProtocolDecl *P = 0) const {
+ return lookupMethod(Sel, false/*isInstance*/, shallowCategoryLookup, 0, P);
}
ObjCInterfaceDecl *lookupInheritedClass(const IdentifierInfo *ICName);
Modified: cfe/trunk/include/clang/Basic/Attr.td
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/include/clang/Basic/Attr.td?rev=195323&r1=195322&r2=195323&view=diff
==============================================================================
--- cfe/trunk/include/clang/Basic/Attr.td (original)
+++ cfe/trunk/include/clang/Basic/Attr.td Thu Nov 21 01:20:42 2013
@@ -613,6 +613,12 @@ def ObjCRootClass : InheritableAttr {
let Subjects = [ObjCInterface];
}
+def ObjCSuppressProtocol : InheritableAttr {
+ let Spellings = [GNU<"objc_suppress_protocol">];
+ let Subjects = [ObjCInterface];
+ let Args = [IdentifierArgument<"Protocol", 1>];
+}
+
def Overloadable : Attr {
let Spellings = [GNU<"overloadable">];
}
Modified: cfe/trunk/lib/AST/DeclObjC.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/AST/DeclObjC.cpp?rev=195323&r1=195322&r2=195323&view=diff
==============================================================================
--- cfe/trunk/lib/AST/DeclObjC.cpp (original)
+++ cfe/trunk/lib/AST/DeclObjC.cpp Thu Nov 21 01:20:42 2013
@@ -457,9 +457,11 @@ ObjCInterfaceDecl::lookupNestedProtocol(
/// When argument category "C" is specified, any implicit method found
/// in this category is ignored.
ObjCMethodDecl *ObjCInterfaceDecl::lookupMethod(Selector Sel,
- bool isInstance,
- bool shallowCategoryLookup,
- const ObjCCategoryDecl *C) const {
+ bool isInstance,
+ bool shallowCategoryLookup,
+ const ObjCCategoryDecl *C,
+ const ObjCProtocolDecl *P) const
+{
// FIXME: Should make sure no callers ever do this.
if (!hasDefinition())
return 0;
@@ -470,7 +472,23 @@ ObjCMethodDecl *ObjCInterfaceDecl::looku
if (data().ExternallyCompleted)
LoadExternalDefinition();
- while (ClassDecl != NULL) {
+ while (ClassDecl) {
+ // If we are looking for a method that is part of protocol conformance,
+ // check if the class has been marked to suppress conformance
+ // of that protocol.
+ if (P && ClassDecl->hasAttrs()) {
+ const AttrVec &V = ClassDecl->getAttrs();
+ const IdentifierInfo *PI = P->getIdentifier();
+ for (AttrVec::const_iterator I = V.begin(), E = V.end(); I != E; ++I) {
+ if (const ObjCSuppressProtocolAttr *A =
+ dyn_cast<ObjCSuppressProtocolAttr>(*I)){
+ if (A->getProtocol() == PI) {
+ return 0;
+ }
+ }
+ }
+ }
+
if ((MethodDecl = ClassDecl->getMethod(Sel, isInstance)))
return MethodDecl;
Modified: cfe/trunk/lib/Sema/SemaDeclAttr.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclAttr.cpp?rev=195323&r1=195322&r2=195323&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclAttr.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclAttr.cpp Thu Nov 21 01:20:42 2013
@@ -2134,6 +2134,30 @@ static void handleObjCRootClassAttr(Sema
Attr.getAttributeSpellingListIndex()));
}
+static void handleObjCSuppresProtocolAttr(Sema &S, Decl *D,
+ const AttributeList &Attr) {
+ if (!isa<ObjCInterfaceDecl>(D)) {
+ S.Diag(Attr.getLoc(), diag::err_attribute_wrong_decl_type)
+ << Attr.getName() << ExpectedObjectiveCInterface;
+ return;
+ }
+
+ IdentifierLoc *Parm = NULL;
+ if (Attr.getNumArgs() == 1) {
+ Parm = Attr.isArgIdent(0) ? Attr.getArgAsIdent(0) : 0;
+ }
+
+ if (!Parm) {
+ S.Diag(D->getLocStart(), diag::err_objc_attr_not_id) << Attr.getName() << 1;
+ return;
+ }
+
+ D->addAttr(::new (S.Context)
+ ObjCSuppressProtocolAttr(Attr.getRange(), S.Context, Parm->Ident,
+ Attr.getAttributeSpellingListIndex()));
+}
+
+
static void handleObjCRequiresPropertyDefsAttr(Sema &S, Decl *D,
const AttributeList &Attr) {
if (!isa<ObjCInterfaceDecl>(D)) {
@@ -4690,7 +4714,10 @@ static void ProcessDeclAttribute(Sema &S
case AttributeList::AT_ObjCRootClass:
handleObjCRootClassAttr(S, D, Attr);
break;
- case AttributeList::AT_ObjCRequiresPropertyDefs:
+ case AttributeList::AT_ObjCSuppressProtocol:
+ handleObjCSuppresProtocolAttr(S, D, Attr);
+ break;
+ case AttributeList::AT_ObjCRequiresPropertyDefs:
handleObjCRequiresPropertyDefsAttr (S, D, Attr);
break;
case AttributeList::AT_Unused: handleUnusedAttr (S, D, Attr); break;
Modified: cfe/trunk/lib/Sema/SemaDeclObjC.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/Sema/SemaDeclObjC.cpp?rev=195323&r1=195322&r2=195323&view=diff
==============================================================================
--- cfe/trunk/lib/Sema/SemaDeclObjC.cpp (original)
+++ cfe/trunk/lib/Sema/SemaDeclObjC.cpp Thu Nov 21 01:20:42 2013
@@ -1664,7 +1664,8 @@ void Sema::CheckProtocolMethodDefs(Sourc
if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
!method->isPropertyAccessor() &&
!InsMap.count(method->getSelector()) &&
- (!Super || !Super->lookupInstanceMethod(method->getSelector()))) {
+ (!Super || !Super->lookupInstanceMethod(method->getSelector(),
+ false, PDecl))) {
// If a method is not implemented in the category implementation but
// has been declared in its primary class, superclass,
// or in one of their protocols, no need to issue the warning.
@@ -1676,7 +1677,8 @@ void Sema::CheckProtocolMethodDefs(Sourc
// uses the protocol.
if (ObjCMethodDecl *MethodInClass =
IDecl->lookupInstanceMethod(method->getSelector(),
- true /*shallowCategoryLookup*/))
+ true /*shallowCategoryLookup*/,
+ PDecl))
if (C || MethodInClass->isPropertyAccessor())
continue;
unsigned DIAG = diag::warn_unimplemented_protocol_method;
@@ -1695,10 +1697,13 @@ void Sema::CheckProtocolMethodDefs(Sourc
ObjCMethodDecl *method = *I;
if (method->getImplementationControl() != ObjCMethodDecl::Optional &&
!ClsMap.count(method->getSelector()) &&
- (!Super || !Super->lookupClassMethod(method->getSelector()))) {
+ (!Super || !Super->lookupClassMethod(method->getSelector(),
+ /* shallowCategoryLookup */ false,
+ PDecl))) {
// See above comment for instance method lookups.
if (C && IDecl->lookupClassMethod(method->getSelector(),
- true /*shallowCategoryLookup*/))
+ true /*shallowCategoryLookup*/,
+ PDecl))
continue;
unsigned DIAG = diag::warn_unimplemented_protocol_method;
if (Diags.getDiagnosticLevel(DIAG, ImpLoc) !=
Added: cfe/trunk/test/SemaObjC/protocols-suppress-conformance.m
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/SemaObjC/protocols-suppress-conformance.m?rev=195323&view=auto
==============================================================================
--- cfe/trunk/test/SemaObjC/protocols-suppress-conformance.m (added)
+++ cfe/trunk/test/SemaObjC/protocols-suppress-conformance.m Thu Nov 21 01:20:42 2013
@@ -0,0 +1,27 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s -Wno-objc-root-class
+
+ at protocol FooProto
+- (void) theBestOfTimes; // expected-note {{method 'theBestOfTimes' declared here}}
+ at end
+
+__attribute__((objc_suppress_protocol(FooProto)))
+ at interface Bar
+- (void) theBestOfTimes;
+ at end
+
+ at interface Bar2 : Bar
+ at end
+
+ at interface Baz : Bar2 <FooProto> // expected-note {{required for direct or indirect protocol 'FooProto'}}
+ at end
+
+ at interface Baz2 : Bar2 <FooProto>
+- (void) theBestOfTimes;
+ at end
+
+ at implementation Baz // expected-warning {{method 'theBestOfTimes' in protocol not implemented}}
+ at end
+
+ at implementation Baz2 // no-warning
+- (void) theBestOfTimes {}
+ at end
\ No newline at end of file
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