aaron.ballman updated this revision to Diff 430648.
aaron.ballman marked an inline comment as done.
aaron.ballman added a comment.
Fixes failed AST matching unit test and speculatively fixes a CodeGen test, all
found via precommit CI testing.
CHANGES SINCE LAST ACTION
https://reviews.llvm.org/D125919/new/
https://reviews.llvm.org/D125919
Files:
clang/docs/ReleaseNotes.rst
clang/include/clang/Basic/DiagnosticSemaKinds.td
clang/lib/Sema/SemaType.cpp
clang/test/CodeGen/xcore-stringtype.c
clang/test/Sema/block-call.c
clang/test/Sema/c89.c
clang/test/Sema/function.c
clang/test/Sema/warn-missing-prototypes.c
clang/test/Sema/wg14-dr423.c
clang/test/SemaObjC/block-omitted-return-type.m
clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
clang/unittests/ASTMatchers/ASTMatchersTest.h
Index: clang/unittests/ASTMatchers/ASTMatchersTest.h
===================================================================
--- clang/unittests/ASTMatchers/ASTMatchersTest.h
+++ clang/unittests/ASTMatchers/ASTMatchersTest.h
@@ -60,6 +60,17 @@
const std::unique_ptr<BoundNodesCallback> FindResultReviewer;
};
+inline ArrayRef<TestLanguage> langAnyC() {
+ static const TestLanguage Result[] = {Lang_C89, Lang_C99};
+ return ArrayRef<TestLanguage>(Result);
+}
+
+inline ArrayRef<TestLanguage> langAnyCxx() {
+ static const TestLanguage Result[] = {Lang_CXX03, Lang_CXX11, Lang_CXX14,
+ Lang_CXX17, Lang_CXX20};
+ return ArrayRef<TestLanguage>(Result);
+}
+
inline ArrayRef<TestLanguage> langCxx11OrLater() {
static const TestLanguage Result[] = {Lang_CXX11, Lang_CXX14, Lang_CXX17,
Lang_CXX20};
Index: clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
===================================================================
--- clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
+++ clang/unittests/ASTMatchers/ASTMatchersNodeTest.cpp
@@ -2095,8 +2095,18 @@
}
TEST_P(ASTMatchersTest, QualifiedTypeLocTest_BindsToConstIntFunctionDecl) {
- EXPECT_TRUE(matches("const int f() { return 5; }",
- qualifiedTypeLoc(loc(asString("const int")))));
+ StringRef Code = R"(
+ const int f() { return 5; }
+ )";
+ // In C++, the qualified return type is retained.
+ EXPECT_TRUE(matchesConditionally(
+ Code, qualifiedTypeLoc(loc(asString("const int"))), true, langAnyCxx()));
+ // In C, the qualifications on the return type are dropped, so we expect it
+ // to match 'int' rather than 'const int'.
+ EXPECT_TRUE(matchesConditionally(
+ Code, qualifiedTypeLoc(loc(asString("const int"))), false, langAnyC()));
+ EXPECT_TRUE(
+ matchesConditionally(Code, loc(asString("int")), true, langAnyC()));
}
TEST_P(ASTMatchersTest, QualifiedTypeLocTest_DoesNotBindToUnqualifiedVarDecl) {
Index: clang/test/SemaObjC/block-omitted-return-type.m
===================================================================
--- clang/test/SemaObjC/block-omitted-return-type.m
+++ clang/test/SemaObjC/block-omitted-return-type.m
@@ -23,8 +23,8 @@
void (^simpleBlock4)(void) = ^ const { //expected-warning {{'const' qualifier on omitted return type '<dependent type>' has no effect}}
return;
};
- void (^simpleBlock5)(void) = ^ const void { //expected-error {{incompatible block pointer types initializing 'void (^)(void)' with an expression of type 'const void (^)(void)'}}
- return; // expected-warning@-1 {{function cannot return qualified void type 'const void'}}
+ void (^simpleBlock5)(void) = ^ const void { // OK after DR 423.
+ return;
};
void (^simpleBlock6)(void) = ^ const (void) { //expected-warning {{'const' qualifier on omitted return type '<dependent type>' has no effect}}
return;
Index: clang/test/Sema/wg14-dr423.c
===================================================================
--- /dev/null
+++ clang/test/Sema/wg14-dr423.c
@@ -0,0 +1,31 @@
+// RUN: %clang_cc1 -fsyntax-only -verify %s
+// RUN: %clang_cc1 -ast-dump %s | FileCheck %s
+// expected-no-diagnostics
+
+void GH39595(void) {
+ // Ensure that qualifiers on function return types are dropped as part of the
+ // declaration.
+ extern const int const_int(void);
+ // CHECK: FunctionDecl {{.*}} parent {{.*}} <col:3, col:34> col:20 referenced const_int 'int (void)' extern
+ extern _Atomic int atomic(void);
+ // CHECK: FunctionDecl {{.*}} parent {{.*}} <col:3, col:33> col:22 referenced atomic 'int (void)' extern
+
+ (void)_Generic(const_int(), int : 1);
+ (void)_Generic(atomic(), int : 1);
+
+ // Make sure they're dropped from function pointers as well.
+ _Atomic int (*fp)(void);
+ (void)_Generic(fp(), int : 1);
+}
+
+void casting(void) {
+ // Ensure that qualifiers on cast operations are also dropped.
+ (void)_Generic((const int)12, int : 1);
+
+ struct S { int i; } s;
+ (void)_Generic((const struct S)s, struct S : 1);
+
+ int i;
+ __typeof__((const int)i) j;
+ j = 100; // If we didn't strip the qualifiers during the cast, this would err.
+}
Index: clang/test/Sema/warn-missing-prototypes.c
===================================================================
--- clang/test/Sema/warn-missing-prototypes.c
+++ clang/test/Sema/warn-missing-prototypes.c
@@ -58,9 +58,14 @@
struct MyStruct {};
+// FIXME: because qualifiers are ignored in the return type when forming the
+// type from the declarator, we get the position incorrect for the fix-it hint.
+// It suggests 'const static struct' instead of 'static const struct'. However,
+// thanks to the awful rules of parsing in C, the effect is the same and the
+// code is valid, if a bit funny looking.
const struct MyStruct get_struct() { // expected-warning{{no previous prototype for function 'get_struct'}}
// expected-note@-1{{declare 'static' if the function is not intended to be used outside of this translation unit}}
- // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:1-[[@LINE-2]]:1}:"static "
+ // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:7-[[@LINE-2]]:7}:"static "
struct MyStruct ret;
return ret;
}
@@ -70,7 +75,7 @@
// Two spaces between cost and struct
const struct MyStruct get_struct_2() { // expected-warning{{no previous prototype for function 'get_struct_2'}}
// expected-note@-1{{declare 'static' if the function is not intended to be used outside of this translation unit}}
- // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:1-[[@LINE-2]]:1}:"static "
+ // CHECK: fix-it:"{{.*}}":{[[@LINE-2]]:8-[[@LINE-2]]:8}:"static "
struct MyStruct ret;
return ret;
}
Index: clang/test/Sema/function.c
===================================================================
--- clang/test/Sema/function.c
+++ clang/test/Sema/function.c
@@ -117,6 +117,6 @@
void const Bar (void); // ok on decl
// PR 20146
-void const Bar (void) // expected-warning {{function cannot return qualified void type 'const void'}}
+void const Bar (void) // also okay on defn per DR 423
{
}
Index: clang/test/Sema/c89.c
===================================================================
--- clang/test/Sema/c89.c
+++ clang/test/Sema/c89.c
@@ -107,7 +107,7 @@
void main(void) {} /* expected-error {{'main' must return 'int'}} */
-const int main(void) {} /* expected-error {{'main' must return 'int'}} */
+const int main(void) {} /* OK per DR 423 */
long long ll1 = /* expected-warning {{'long long' is an extension when C99 mode is not enabled}} */
-42LL; /* expected-warning {{'long long' is an extension when C99 mode is not enabled}} */
Index: clang/test/Sema/block-call.c
===================================================================
--- clang/test/Sema/block-call.c
+++ clang/test/Sema/block-call.c
@@ -22,7 +22,7 @@
int * const (^IPCC1) () = IPCC;
- int * (^IPCC2) () = IPCC; // expected-error {{incompatible block pointer types initializing 'int *(^)()' with an expression of type 'int *const (^)()'}}
+ int * (^IPCC2) () = IPCC; // OK per WG14 DR 423 because the 'const' was dropped from the declarator.
int (^IPCC3) (const int) = PFR;
@@ -33,7 +33,7 @@
int (^IPCC6) (int, char (^CArg) (float)) = IPCC4; // expected-error {{incompatible block pointer types initializing 'int (^)(int, char (^)(float))' with an expression of type 'int (^)(int, char (^)(double))'}}
IPCC2 = 0;
- IPCC1 = 1; // expected-error {{invalid block pointer conversion assigning to 'int *const (^)()' from 'int'}}
+ IPCC1 = 1; // expected-error {{invalid block pointer conversion assigning to 'int *(^)()' from 'int'}}
int (^x)() = 0;
int (^y)() = 3; // expected-error {{invalid block pointer conversion initializing 'int (^)()' with an expression of type 'int'}}
int a = 1;
Index: clang/test/CodeGen/xcore-stringtype.c
===================================================================
--- clang/test/CodeGen/xcore-stringtype.c
+++ clang/test/CodeGen/xcore-stringtype.c
@@ -42,8 +42,8 @@
// CHECK: !{{[0-9]+}} = !{void ()* @eV, !"f{0}(0)"}
// CHECK: !{{[0-9]+}} = !{void (i32, ...)* @gVA, !"f{0}(si,va)"}
// CHECK: !{{[0-9]+}} = !{void (i32, ...)* @eVA, !"f{0}(si,va)"}
-// CHECK: !{{[0-9]+}} = !{i32* (i32*)* @gQ, !"f{crv:p(cv:si)}(p(cv:si))"}
-// CHECK: !{{[0-9]+}} = !{i32* (i32*)* @eQ, !"f{crv:p(cv:si)}(p(cv:si))"}
+// CHECK: !{{[0-9]+}} = !{i32* (i32*)* @gQ, !"f{p(cv:si)}(p(cv:si))"}
+// CHECK: !{{[0-9]+}} = !{i32* (i32*)* @eQ, !"f{p(cv:si)}(p(cv:si))"}
extern void eI();
void gI() {eI();};
extern void eV(void);
Index: clang/lib/Sema/SemaType.cpp
===================================================================
--- clang/lib/Sema/SemaType.cpp
+++ clang/lib/Sema/SemaType.cpp
@@ -5181,15 +5181,11 @@
if ((T.getCVRQualifiers() || T->isAtomicType()) &&
!(S.getLangOpts().CPlusPlus &&
(T->isDependentType() || T->isRecordType()))) {
- if (T->isVoidType() && !S.getLangOpts().CPlusPlus &&
- D.getFunctionDefinitionKind() ==
- FunctionDefinitionKind::Definition) {
- // [6.9.1/3] qualified void return is invalid on a C
- // function definition. Apparently ok on declarations and
- // in C++ though (!)
- S.Diag(DeclType.Loc, diag::err_func_returning_qualified_void) << T;
- } else
- diagnoseRedundantReturnTypeQualifiers(S, T, D, chunkIndex);
+ // WG14 DR 423 updated 6.7.6.3p4 to have the function declarator drop
+ // all qualifiers from the return type.
+ diagnoseRedundantReturnTypeQualifiers(S, T, D, chunkIndex);
+ if (!S.getLangOpts().CPlusPlus)
+ T = T.getAtomicUnqualifiedType();
// C++2a [dcl.fct]p12:
// A volatile-qualified return type is deprecated
Index: clang/include/clang/Basic/DiagnosticSemaKinds.td
===================================================================
--- clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -6135,9 +6135,6 @@
def note_exits_compound_literal_scope : Note<
"jump exits lifetime of a compound literal that is non-trivial to destruct">;
-def err_func_returning_qualified_void : ExtWarn<
- "function cannot return qualified void type %0">,
- InGroup<DiagGroup<"qualified-void-return-type">>;
def err_func_returning_array_function : Error<
"function cannot return %select{array|function}0 type %1">;
def err_field_declared_as_function : Error<"field %0 declared as a function">;
Index: clang/docs/ReleaseNotes.rst
===================================================================
--- clang/docs/ReleaseNotes.rst
+++ clang/docs/ReleaseNotes.rst
@@ -340,6 +340,11 @@
C Language Changes in Clang
---------------------------
+- Finished implementing support for DR423. We already correctly handled
+ stripping qualifiers from cast expressions, but we did not strip qualifiers
+ on function return types. We now properly treat the function as though it
+ were declarated with an unqualified, non-atomic return type. Fixes
+ `Issue 39595 <https://github.com/llvm/llvm-project/issues/39595>`_.
C2x Feature Support
-------------------
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