https://github.com/Sirraide created
https://github.com/llvm/llvm-project/pull/135679
NB: This only fixes the crash introduced in Clang 19; we still accept this code
even though we shouldn’t:
```c++
struct S {
friend int f() { return 3; }
friend int f() = delete;
};
```
I tried figuring out a way to diagnose this redeclaration, but it seems tricky
because I kept running into issues around defaulted comparison operators. From
my testing, however, this fix here would still be required even once we do
start diagnosing this.
Fixes #135506.
>From daa795d3807ecdceedb764582a01396c3b7f2e2f Mon Sep 17 00:00:00 2001
From: Sirraide <aeternalm...@gmail.com>
Date: Mon, 14 Apr 2025 22:54:11 +0200
Subject: [PATCH] [Clang] [Sema] Fix a crash when a `friend` function is
redefined as deleted
---
clang/docs/ReleaseNotes.rst | 2 +-
clang/lib/Sema/SemaDecl.cpp | 15 ++++------
.../SemaCXX/cxx2c-delete-with-message.cpp | 30 +++++++++++++++++++
3 files changed, 36 insertions(+), 11 deletions(-)
diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst
index 11f62bc881b03..037f9f6fe79e0 100644
--- a/clang/docs/ReleaseNotes.rst
+++ b/clang/docs/ReleaseNotes.rst
@@ -389,7 +389,7 @@ Bug Fixes in This Version
#if 1 ? 1 : 999999999999999999999
#endif
-
+- Fixed a crash when a ``friend`` function is redefined as deleted. (#GH135506)
Bug Fixes to Compiler Builtins
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index e9805c345b6af..8fd857d347895 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -16178,16 +16178,11 @@ Decl *Sema::ActOnFinishFunctionBody(Decl *dcl, Stmt
*Body,
// This is meant to pop the context added in ActOnStartOfFunctionDef().
ExitFunctionBodyRAII ExitRAII(*this, isLambdaCallOperator(FD));
if (FD) {
- // If this is called by Parser::ParseFunctionDefinition() after marking
- // the declaration as deleted, and if the deleted-function-body contains
- // a message (C++26), then a DefaultedOrDeletedInfo will have already
been
- // added to store that message; do not overwrite it in that case.
- //
- // Since this would always set the body to 'nullptr' in that case anyway,
- // which is already done when the function decl is initially created,
- // always skipping this irrespective of whether there is a delete message
- // should not be a problem.
- if (!FD->isDeletedAsWritten())
+ // The function body and the DefaultedOrDeletedInfo, if present, use
+ // the same storage; don't overwrite the latter if the former is null
+ // (the body is initialised to null anyway, so even if the latter isn't
+ // present, this would still be a no-op).
+ if (Body)
FD->setBody(Body);
FD->setWillHaveBody(false);
diff --git a/clang/test/SemaCXX/cxx2c-delete-with-message.cpp
b/clang/test/SemaCXX/cxx2c-delete-with-message.cpp
index 22e65d902ecd4..5609da18c05aa 100644
--- a/clang/test/SemaCXX/cxx2c-delete-with-message.cpp
+++ b/clang/test/SemaCXX/cxx2c-delete-with-message.cpp
@@ -271,3 +271,33 @@ void operators() {
if (to_int_int) {} // expected-error {{attempt to use a deleted function:
deleted (TO<int, int>, operator bool)}}
static_cast<bool>(to_int_int); // expected-error {{static_cast from 'TO<int,
int>' to 'bool' uses deleted function: deleted (TO<int, int>, operator bool)}}
};
+
+namespace gh135506 {
+struct a {
+ // FIXME: We currently don't diagnose these invalid redeclarations if the
+ // second declaration is defaulted or deleted. This probably needs to be
+ // handled in ParseCXXInlineMethodDef() after parsing the defaulted/deleted
+ // body.
+ friend consteval int f() { return 3; }
+ friend consteval int f() = delete("foo");
+
+ friend consteval int g() { return 3; }
+ friend consteval int g() = delete;
+
+ friend int h() { return 3; }
+ friend int h() = delete;
+
+ friend consteval int i() = delete; // expected-note {{previous definition is
here}}
+ friend consteval int i() { return 3; } // expected-error {{redefinition of
'i'}}
+};
+
+struct b {
+ friend consteval bool operator==(b, b) { return true; } // expected-note
{{previous declaration is here}}
+ friend consteval bool operator==(b, b) = default; // expected-error
{{defaulting this equality comparison operator is not allowed because it was
already declared outside the class}}
+};
+
+struct c {
+ friend consteval bool operator==(c, c) = default; // expected-note
{{previous definition is here}}
+ friend consteval bool operator==(c, c) { return true; } // expected-error
{{redefinition of 'operator=='}}
+};
+}
_______________________________________________
cfe-commits mailing list
cfe-commits@lists.llvm.org
https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
