arphaman created this revision.
arphaman added reviewers: rjmccall, ahatanak, erik.pilkington, jfb.
Herald added a subscriber: dexonsmith.
Clang emits invalid protocol metadata when a `@protocol` expression is used
with a forward-declared protocol. The protocol metadata is missing protocol
conformance list of the protocol since we don't have access to the definition
of it in the compiled translation unit. The linker then might end up picking
the invalid metadata when linking which will lead to incorrect runtime protocol
conformance checks.
This patch makes sure that Clang fails to compile code that uses a `@protocol`
expression with a forward-declared protocol. This ensures that Clang does not
emit invalid protocol metadata. I added an extra assert in CodeGen to ensure
that this kind of issue won't happen in other places.
Repository:
rC Clang
https://reviews.llvm.org/D49462
Files:
include/clang/Basic/DiagnosticSemaKinds.td
lib/CodeGen/CGObjCMac.cpp
lib/Sema/SemaExpr.cpp
lib/Sema/SemaExprObjC.cpp
test/CodeGenObjC/forward-declare-protocol-gnu.m
test/CodeGenObjC/forward-protocol-metadata-symbols.m
test/CodeGenObjC/hidden-visibility.m
test/CodeGenObjC/link-errors.m
test/CodeGenObjC/protocol-comdat.m
test/CodeGenObjC/protocols-lazy.m
test/CodeGenObjC/protocols.m
test/PCH/objc_exprs.h
test/Parser/objc-cxx-keyword-identifiers.mm
test/SemaObjC/protocol-expr-neg-1.m
Index: test/SemaObjC/protocol-expr-neg-1.m
===================================================================
--- test/SemaObjC/protocol-expr-neg-1.m
+++ test/SemaObjC/protocol-expr-neg-1.m
@@ -12,7 +12,7 @@
int main()
{
Protocol *proto = @protocol(p1);
- Protocol *fproto = @protocol(fproto); // expected-warning {{@protocol is using a forward protocol declaration of 'fproto'}}
+ Protocol *fproto = @protocol(fproto); // expected-error {{@protocol is using a forward protocol declaration of 'fproto'}}
Protocol *pp = @protocol(i); // expected-error {{cannot find protocol declaration for 'i'}}
Protocol *p1p = @protocol(cl); // expected-error {{cannot find protocol declaration for 'cl'}}
}
@@ -26,9 +26,9 @@
@end
int doesConform(id foo) {
- return [foo conformsToProtocol:@protocol(TestProtocol)]; // expected-warning {{@protocol is using a forward protocol declaration of 'TestProtocol'}}
+ return [foo conformsToProtocol:@protocol(TestProtocol)]; // expected-error {{@protocol is using a forward protocol declaration of 'TestProtocol'}}
}
int doesConformSuper(id foo) {
- return [foo conformsToProtocol:@protocol(SuperProtocol)]; // expected-warning {{@protocol is using a forward protocol declaration of 'SuperProtocol'}}
+ return [foo conformsToProtocol:@protocol(SuperProtocol)]; // expected-error {{@protocol is using a forward protocol declaration of 'SuperProtocol'}}
}
Index: test/Parser/objc-cxx-keyword-identifiers.mm
===================================================================
--- test/Parser/objc-cxx-keyword-identifiers.mm
+++ test/Parser/objc-cxx-keyword-identifiers.mm
@@ -18,7 +18,9 @@
@protocol new // expected-error {{expected identifier; 'new' is a keyword in Objective-C++}}
@end
-@protocol P2, delete; // expected-error {{expected identifier; 'delete' is a keyword in Objective-C++}}
+@protocol P2;
+@protocol delete // expected-error {{expected identifier; 'delete' is a keyword in Objective-C++}}
+@end
@class Foo, try; // expected-error {{expected identifier; 'try' is a keyword in Objective-C++}}
Index: test/PCH/objc_exprs.h
===================================================================
--- test/PCH/objc_exprs.h
+++ test/PCH/objc_exprs.h
@@ -1,11 +1,13 @@
@protocol foo;
+@protocol foo2
+@end
@class itf;
// Expressions
typedef typeof(@"foo" "bar") objc_string;
typedef typeof(@encode(int)) objc_encode;
-typedef typeof(@protocol(foo)) objc_protocol;
+typedef typeof(@protocol(foo2)) objc_protocol;
typedef typeof(@selector(noArgs)) objc_selector_noArgs;
typedef typeof(@selector(oneArg:)) objc_selector_oneArg;
typedef typeof(@selector(foo:bar:)) objc_selector_twoArg;
Index: test/CodeGenObjC/protocols.m
===================================================================
--- test/CodeGenObjC/protocols.m
+++ test/CodeGenObjC/protocols.m
@@ -7,7 +7,8 @@
-(int) conformsTo: (id) x;
@end
-@protocol P0;
+@protocol P0
+@end
@protocol P1
+(void) classMethodReq0;
Index: test/CodeGenObjC/protocols-lazy.m
===================================================================
--- test/CodeGenObjC/protocols-lazy.m
+++ test/CodeGenObjC/protocols-lazy.m
@@ -18,7 +18,10 @@
// RUN: grep OBJC_PROTOCOL_P3 %t | count 3
// RUN: not grep OBJC_PROTOCOL_INSTANCE_METHODS_P3 %t
@protocol P3;
-void f1() { id x = @protocol(P3); }
+@interface UserP3<P3>
+@end
+@implementation UserP3
+@end
// Definition triggered by class reference.
// RUN: grep OBJC_PROTOCOL_P4 %t | count 3
@@ -31,10 +34,16 @@
// RUN: grep OBJC_PROTOCOL_P5 %t | count 3
// RUN: grep OBJC_PROTOCOL_INSTANCE_METHODS_P5 %t | count 3
@protocol P5;
-void f2() { id x = @protocol(P5); } // This generates a forward
- // reference, which has to be
- // updated on the next line.
-@protocol P5 -im1; @end
+@interface UserP5<P5> // This generates a forward
+ // reference, which has to be
+ // updated on the next line.
+@end
+@protocol P5 -im1; @end
+@implementation UserP5
+
+- im1 { }
+
+@end
// Protocol reference following definition.
// RUN: grep OBJC_PROTOCOL_P6 %t | count 4
Index: test/CodeGenObjC/protocol-comdat.m
===================================================================
--- test/CodeGenObjC/protocol-comdat.m
+++ test/CodeGenObjC/protocol-comdat.m
@@ -4,8 +4,8 @@
- (void) method;
@end
-@protocol Q;
-@protocol R;
+@protocol Q @end
+@protocol R @end
@interface I<P>
@end
Index: test/CodeGenObjC/link-errors.m
===================================================================
--- test/CodeGenObjC/link-errors.m
+++ test/CodeGenObjC/link-errors.m
@@ -10,7 +10,7 @@
-(id) init;
@end
-@protocol P;
+@protocol P @end
@interface A : Root
@end
Index: test/CodeGenObjC/hidden-visibility.m
===================================================================
--- test/CodeGenObjC/hidden-visibility.m
+++ test/CodeGenObjC/hidden-visibility.m
@@ -16,7 +16,7 @@
@end
-@protocol Prot0;
+@protocol Prot0 @end
id f0() {
return @protocol(Prot0);
Index: test/CodeGenObjC/forward-protocol-metadata-symbols.m
===================================================================
--- test/CodeGenObjC/forward-protocol-metadata-symbols.m
+++ test/CodeGenObjC/forward-protocol-metadata-symbols.m
@@ -3,7 +3,7 @@
@interface NSObject @end
-@protocol P0;
+@protocol P0 @end
@interface A : NSObject <P0>
+(Class) getClass;
@@ -19,8 +19,8 @@
}
// CHECK: @"\01l_OBJC_PROTOCOL_$_P0" = weak hidden global
-// CHECK: @"\01l_OBJC_CLASS_PROTOCOLS_$_A" = private global
// CHECK: @"\01l_OBJC_LABEL_PROTOCOL_$_P0" = weak hidden global
+// CHECK: @"\01l_OBJC_CLASS_PROTOCOLS_$_A" = private global
// CHECK: @"\01l_OBJC_PROTOCOL_REFERENCE_$_P0" = weak hidden global
// CHECK: llvm.used = appending global [3 x i8*]
@@ -33,7 +33,7 @@
// CHECK-SAME: OBJC_METH_VAR_NAME_
// CHECK-SAME: OBJC_METH_VAR_TYPE_
// CHECK-SAME: "\01l_OBJC_$_CLASS_METHODS_A"
-// CHECK-SAME: "\01l_OBJC_CLASS_PROTOCOLS_$_A"
// CHECK-SAME: OBJC_CLASS_NAME_.1
+// CHECK-SAME: "\01l_OBJC_CLASS_PROTOCOLS_$_A"
// CHECK-SAME: "OBJC_LABEL_CLASS_$"
// CHECK-SAME: section "llvm.metadata"
Index: test/CodeGenObjC/forward-declare-protocol-gnu.m
===================================================================
--- test/CodeGenObjC/forward-declare-protocol-gnu.m
+++ test/CodeGenObjC/forward-declare-protocol-gnu.m
@@ -3,9 +3,11 @@
// Regression test: check that we don't crash when referencing a forward-declared protocol.
@protocol P;
-Protocol *getProtocol(void)
-{
- return @protocol(P);
-}
+@interface I <P>
+@end
+
+@implementation I
+
+@end
// CHECK: @.objc_protocol
Index: lib/Sema/SemaExprObjC.cpp
===================================================================
--- lib/Sema/SemaExprObjC.cpp
+++ lib/Sema/SemaExprObjC.cpp
@@ -1228,7 +1228,10 @@
Diag(ProtoLoc, diag::err_undeclared_protocol) << ProtocolId;
return true;
}
- if (PDecl->hasDefinition())
+ if (!PDecl->hasDefinition()) {
+ Diag(ProtoLoc, diag::err_atprotocol_protocol) << PDecl;
+ Diag(PDecl->getLocation(), diag::note_entity_declared_at) << PDecl;
+ } else
PDecl = PDecl->getDefinition();
QualType Ty = Context.getObjCProtoType();
Index: lib/Sema/SemaExpr.cpp
===================================================================
--- lib/Sema/SemaExpr.cpp
+++ lib/Sema/SemaExpr.cpp
@@ -8086,15 +8086,6 @@
if (RHS.isInvalid())
return Incompatible;
}
-
- Expr *PRE = RHS.get()->IgnoreParenCasts();
- if (Diagnose && isa<ObjCProtocolExpr>(PRE)) {
- ObjCProtocolDecl *PDecl = cast<ObjCProtocolExpr>(PRE)->getProtocol();
- if (PDecl && !PDecl->hasDefinition()) {
- Diag(PRE->getExprLoc(), diag::warn_atprotocol_protocol) << PDecl;
- Diag(PDecl->getLocation(), diag::note_entity_declared_at) << PDecl;
- }
- }
CastKind Kind;
Sema::AssignConvertType result =
Index: lib/CodeGen/CGObjCMac.cpp
===================================================================
--- lib/CodeGen/CGObjCMac.cpp
+++ lib/CodeGen/CGObjCMac.cpp
@@ -6783,9 +6783,10 @@
return Entry;
// Use the protocol definition, if there is one.
- if (const ObjCProtocolDecl *Def = PD->getDefinition())
- PD = Def;
-
+ assert(PD->hasDefinition() &&
+ "emitting protocol metadata without definition");
+ PD = PD->getDefinition();
+
auto methodLists = ProtocolMethodLists::get(PD);
ConstantInitBuilder builder(CGM);
Index: include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- include/clang/Basic/DiagnosticSemaKinds.td
+++ include/clang/Basic/DiagnosticSemaKinds.td
@@ -845,8 +845,8 @@
"protocol has circular dependency">;
def err_undeclared_protocol : Error<"cannot find protocol declaration for %0">;
def warn_undef_protocolref : Warning<"cannot find protocol definition for %0">;
-def warn_atprotocol_protocol : Warning<
- "@protocol is using a forward protocol declaration of %0">, InGroup<AtProtocol>;
+def err_atprotocol_protocol : Error<
+ "@protocol is using a forward protocol declaration of %0">;
def warn_readonly_property : Warning<
"attribute 'readonly' of property %0 restricts attribute "
"'readwrite' of property inherited from %1">,
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
