[clang] [Clang][Sema] Disallow applying `onwership_returns` to functions that return non-pointers (PR #99564)
Pavel Skripkin via cfe-commits
cfe-commits at lists.llvm.org
Fri Jul 19 10:03:33 PDT 2024
https://github.com/pskrgag updated https://github.com/llvm/llvm-project/pull/99564
>From f517162e629535446f5a261b81aa11b3155de6ed Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin at gmail.com>
Date: Thu, 18 Jul 2024 18:48:47 +0300
Subject: [PATCH 1/4] clang/sema: disallow ownership_returns for functions that
return non-pointers
ownership_takes expects an argument to a pointer and clang reports an
error if it is not the case.
Since pointers consumed by ownership_takes are produced by functions
with ownership_returns attribute, it make sence to report an error
if function does not return a pointer type.
---
clang/include/clang/Basic/DiagnosticSemaKinds.td | 2 ++
clang/lib/Sema/SemaDeclAttr.cpp | 11 +++++++++++
clang/test/AST/attr-print-emit.cpp | 4 ++--
clang/test/Sema/attr-ownership.c | 5 ++++-
clang/test/Sema/attr-ownership.cpp | 6 +++---
5 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/clang/include/clang/Basic/DiagnosticSemaKinds.td b/clang/include/clang/Basic/DiagnosticSemaKinds.td
index d60f32674ca3a..09d19e6e4b4fc 100644
--- a/clang/include/clang/Basic/DiagnosticSemaKinds.td
+++ b/clang/include/clang/Basic/DiagnosticSemaKinds.td
@@ -3324,6 +3324,8 @@ def err_attribute_invalid_implicit_this_argument : Error<
"%0 attribute is invalid for the implicit this argument">;
def err_ownership_type : Error<
"%0 attribute only applies to %select{pointer|integer}1 arguments">;
+def err_ownership_takes_return_type : Error<
+ "'ownership_returns' attribute only applies to functions that return pointers">;
def err_ownership_returns_index_mismatch : Error<
"'ownership_returns' attribute index does not match; here it is %0">;
def note_ownership_returns_index_mismatch : Note<
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 41295bfb3b94f..06fd5c756a94d 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -1481,6 +1481,17 @@ static void handleOwnershipAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
break;
}
+ // Allow only pointers to be return type for functions with ownership_takes
+ // attribute. This matches with current OwnershipAttr::Takes semantics
+ if (K == OwnershipAttr::Returns) {
+ QualType RetType = getFunctionOrMethodResultType(D);
+
+ if (!RetType->isPointerType()) {
+ S.Diag(AL.getLoc(), diag::err_ownership_takes_return_type) << AL;
+ return;
+ }
+ }
+
IdentifierInfo *Module = AL.getArgAsIdent(0)->Ident;
StringRef ModuleName = Module->getName();
diff --git a/clang/test/AST/attr-print-emit.cpp b/clang/test/AST/attr-print-emit.cpp
index 8c8a2b2080599..9c89764a3cac2 100644
--- a/clang/test/AST/attr-print-emit.cpp
+++ b/clang/test/AST/attr-print-emit.cpp
@@ -33,7 +33,7 @@ void ownt(int *, int *) __attribute__((ownership_takes(foo, 1, 2)));
// CHECK: void ownh(int *, int *) __attribute__((ownership_holds(foo, 1, 2)));
void ownh(int *, int *) __attribute__((ownership_holds(foo, 1, 2)));
// CHECK: void ownr(int) __attribute__((ownership_returns(foo, 1)));
-void ownr(int) __attribute__((ownership_returns(foo, 1)));
+void *ownr(int) __attribute__((ownership_returns(foo, 1)));
// CHECK: void awtt(int, int, ...) __attribute__((argument_with_type_tag(foo, 3, 2)));
void awtt(int, int, ...) __attribute__((argument_with_type_tag(foo, 3, 2)));
@@ -66,7 +66,7 @@ class C {
// CHECK: void ownh(int *, int *) __attribute__((ownership_holds(foo, 2, 3)));
void ownh(int *, int *) __attribute__((ownership_holds(foo, 2, 3)));
// CHECK: void ownr(int) __attribute__((ownership_returns(foo, 2)));
- void ownr(int) __attribute__((ownership_returns(foo, 2)));
+ void *ownr(int) __attribute__((ownership_returns(foo, 2)));
// CHECK: void awtt(int, int, ...) __attribute__((argument_with_type_tag(foo, 4, 3)));
void awtt(int, int, ...) __attribute__((argument_with_type_tag(foo, 4, 3)));
diff --git a/clang/test/Sema/attr-ownership.c b/clang/test/Sema/attr-ownership.c
index 8157ba7145a24..28b7cf25a21d5 100644
--- a/clang/test/Sema/attr-ownership.c
+++ b/clang/test/Sema/attr-ownership.c
@@ -18,9 +18,12 @@ void *f12(float i, int k, int f, int *j) __attribute__((ownership_returns(foo, 4
void f13(int *i, int *j) __attribute__((ownership_holds(foo, 1))) __attribute__((ownership_takes(foo, 2)));
void f14(int i, int j, int *k) __attribute__((ownership_holds(foo, 3))) __attribute__((ownership_takes(foo, 3))); // expected-error {{'ownership_takes' and 'ownership_holds' attributes are not compatible}}
-void f15(int, int)
+void *f15(int, int)
__attribute__((ownership_returns(foo, 1))) // expected-error {{'ownership_returns' attribute index does not match; here it is 1}}
__attribute__((ownership_returns(foo, 2))); // expected-note {{declared with index 2 here}}
void f16(int *i, int *j) __attribute__((ownership_holds(foo, 1))) __attribute__((ownership_holds(foo, 1))); // OK, same index
void f17(void*) __attribute__((ownership_takes(__, 1)));
void f18() __attribute__((ownership_takes(foo, 1))); // expected-warning {{'ownership_takes' attribute only applies to non-K&R-style functions}}
+
+void f18(void) __attribute__((ownership_returns(foo))); // expected-error {{'ownership_returns' attribute only applies to functions that return pointers}}
+int f19(void) __attribute__((ownership_returns(foo))); // expected-error {{'ownership_returns' attribute only applies to functions that return pointers}}
diff --git a/clang/test/Sema/attr-ownership.cpp b/clang/test/Sema/attr-ownership.cpp
index 7381285e2da48..0626efa5aaf9a 100644
--- a/clang/test/Sema/attr-ownership.cpp
+++ b/clang/test/Sema/attr-ownership.cpp
@@ -1,7 +1,7 @@
// RUN: %clang_cc1 %s -verify -fsyntax-only
class C {
- void f(int, int)
- __attribute__((ownership_returns(foo, 2))) // expected-error {{'ownership_returns' attribute index does not match; here it is 2}}
- __attribute__((ownership_returns(foo, 3))); // expected-note {{declared with index 3 here}}
+ void *f(int, int)
+ __attribute__((ownership_returns(foo, 2))) // expected-error {{'ownership_returns' attribute index does not match; here it is 2}}
+ __attribute__((ownership_returns(foo, 3))); // expected-note {{declared with index 3 here}}
};
>From 80b1a1d818964be18e9dc9d3ac62786ee53b8e36 Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin at gmail.com>
Date: Thu, 18 Jul 2024 22:28:15 +0300
Subject: [PATCH 2/4] add release note
---
clang/docs/ReleaseNotes.rst | 4 ++++
1 file changed, 4 insertions(+)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index e0e86af257a19..4ecdf41a59234 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -1308,6 +1308,10 @@ Crash and bug fixes
Improvements
^^^^^^^^^^^^
+- Improved handling of ``__attribute__((ownership_returns(class, idx)))``. Now clang
+ reports an error if attribute is attached to a function that returns non-pointer
+ value
+
Moved checkers
^^^^^^^^^^^^^^
>From f6fb8d8fe2458009a20ed0f0f9be97bfa1411d99 Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin at gmail.com>
Date: Fri, 19 Jul 2024 20:02:17 +0300
Subject: [PATCH 3/4] Fixed wrong comment and fixed release note wording
---
clang/docs/ReleaseNotes.rst | 6 +++---
clang/lib/Sema/SemaDeclAttr.cpp | 2 +-
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 4ecdf41a59234..417acd4fe0336 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -1308,9 +1308,9 @@ Crash and bug fixes
Improvements
^^^^^^^^^^^^
-- Improved handling of ``__attribute__((ownership_returns(class, idx)))``. Now clang
- reports an error if attribute is attached to a function that returns non-pointer
- value
+- Improved the handling of the `ownership_returns` attribute. Now, Clang reports an
+ error if the attribute is attached to a function that returns a non-pointer value.
+ Fixes (#GH99501)
Moved checkers
^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaDeclAttr.cpp b/clang/lib/Sema/SemaDeclAttr.cpp
index 06fd5c756a94d..eb3595ccd4264 100644
--- a/clang/lib/Sema/SemaDeclAttr.cpp
+++ b/clang/lib/Sema/SemaDeclAttr.cpp
@@ -1481,7 +1481,7 @@ static void handleOwnershipAttr(Sema &S, Decl *D, const ParsedAttr &AL) {
break;
}
- // Allow only pointers to be return type for functions with ownership_takes
+ // Allow only pointers to be return type for functions with ownership_returns
// attribute. This matches with current OwnershipAttr::Takes semantics
if (K == OwnershipAttr::Returns) {
QualType RetType = getFunctionOrMethodResultType(D);
>From 68207991aaeceb83d654185ca99cbf6a0cb4da71 Mon Sep 17 00:00:00 2001
From: Pavel Skripkin <paskripkin at gmail.com>
Date: Fri, 19 Jul 2024 20:02:47 +0300
Subject: [PATCH 4/4] Fix attr-print-emit test after fixing ownership_returns
semantics
---
clang/test/AST/attr-print-emit.cpp | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/clang/test/AST/attr-print-emit.cpp b/clang/test/AST/attr-print-emit.cpp
index 9c89764a3cac2..d8e62ed5f6cd1 100644
--- a/clang/test/AST/attr-print-emit.cpp
+++ b/clang/test/AST/attr-print-emit.cpp
@@ -32,7 +32,7 @@ int *aa(int i) __attribute__((alloc_align(1)));
void ownt(int *, int *) __attribute__((ownership_takes(foo, 1, 2)));
// CHECK: void ownh(int *, int *) __attribute__((ownership_holds(foo, 1, 2)));
void ownh(int *, int *) __attribute__((ownership_holds(foo, 1, 2)));
-// CHECK: void ownr(int) __attribute__((ownership_returns(foo, 1)));
+// CHECK: void *ownr(int) __attribute__((ownership_returns(foo, 1)));
void *ownr(int) __attribute__((ownership_returns(foo, 1)));
// CHECK: void awtt(int, int, ...) __attribute__((argument_with_type_tag(foo, 3, 2)));
@@ -65,7 +65,7 @@ class C {
void ownt(int *, int *) __attribute__((ownership_takes(foo, 2, 3)));
// CHECK: void ownh(int *, int *) __attribute__((ownership_holds(foo, 2, 3)));
void ownh(int *, int *) __attribute__((ownership_holds(foo, 2, 3)));
- // CHECK: void ownr(int) __attribute__((ownership_returns(foo, 2)));
+ // CHECK: void *ownr(int) __attribute__((ownership_returns(foo, 2)));
void *ownr(int) __attribute__((ownership_returns(foo, 2)));
// CHECK: void awtt(int, int, ...) __attribute__((argument_with_type_tag(foo, 4, 3)));
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