https://github.com/erichkeane updated https://github.com/llvm/llvm-project/pull/203522
>From 54ef6be9eb9ceede3443636be62d9d9620830db7 Mon Sep 17 00:00:00 2001 From: erichkeane <[email protected]> Date: Fri, 12 Jun 2026 06:00:07 -0700 Subject: [PATCH 1/2] Fix contextual implicit conversions to int: with _Atomic PerformContextualImplicitConversion was performing default-lvalue-conversions, then basing decisions on viable conversion functions on this type However, when we then went to add the candidates we were using the 'old' value (pre-conversion) of the type, resulting in us regaining the lost 'atomic' from the default Lvalue conversion. This patch updates the 'from' variable to be the converted value so all conversions are done post-conversion. Fixes: #201770 --- clang/docs/ReleaseNotes.rst | 1 + clang/lib/Sema/SemaOverload.cpp | 2 ++ clang/test/Sema/atomic-conversions-to-int.cpp | 25 +++++++++++++++++++ 3 files changed, 28 insertions(+) create mode 100644 clang/test/Sema/atomic-conversions-to-int.cpp diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index a984982d1bd41..7828135a6edbc 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -705,6 +705,7 @@ Bug Fixes in This Version - Fixed crash when checking for overflow for unary operator that can't overflow (#GH170072) - Clang no longer handles a `" q-char-sequence "` header name as a string literal (#GH132643). - Fixed an assertion when ``__attribute__((alloc_size))`` is used with an argument type wider than the target's pointer width. (#GH190445) +- Fixed an assertion where we improperly handled implicit conversions to integral types from an atomic-type with a conversion function. (#GH201770) Bug Fixes to Compiler Builtins ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp index ecda430c8424a..70cff11efb71b 100644 --- a/clang/lib/Sema/SemaOverload.cpp +++ b/clang/lib/Sema/SemaOverload.cpp @@ -7031,10 +7031,12 @@ ExprResult Sema::PerformContextualImplicitConversion( // Try converting the expression to an Lvalue first, to get rid of qualifiers. ExprResult Converted = DefaultLvalueConversion(From); QualType T = Converted.isUsable() ? Converted.get()->getType() : QualType(); + From = Converted.get(); // If the expression already has a matching type, we're golden. if (Converter.match(T)) return Converted; + // FIXME: Check for missing '()' if T is a function type? // We can only perform contextual implicit conversions on objects of class diff --git a/clang/test/Sema/atomic-conversions-to-int.cpp b/clang/test/Sema/atomic-conversions-to-int.cpp new file mode 100644 index 0000000000000..6f3b82007935e --- /dev/null +++ b/clang/test/Sema/atomic-conversions-to-int.cpp @@ -0,0 +1,25 @@ +// RUN: %clang_cc1 -triple x86_64-linux -Wunused -verify %s + +struct Convert { + operator unsigned() const; +}; + +struct NoConvert { + operator float() const; +}; + +struct H { + static _Atomic Convert conv; + static _Atomic NoConvert noconv; +}; + +void foo() { + switch(H::conv){} + (void)__builtin_stdc_rotate_left(H::conv, H::conv); + + // expected-error@+1{{statement requires expression of integer type ('NoConvert' invalid)}} + switch(H::noconv){} + // expected-error@+1{{1st argument must be a scalar unsigned integer type (was 'NoConvert')}} + (void)__builtin_stdc_rotate_left(H::noconv, H::noconv); +} + >From bead0f78b564ac5c508c104413e4b9db1ce3a72c Mon Sep 17 00:00:00 2001 From: erichkeane <[email protected]> Date: Fri, 12 Jun 2026 06:11:29 -0700 Subject: [PATCH 2/2] Clang-format --- clang/lib/Sema/SemaOverload.cpp | 1 - 1 file changed, 1 deletion(-) diff --git a/clang/lib/Sema/SemaOverload.cpp b/clang/lib/Sema/SemaOverload.cpp index 70cff11efb71b..599264b19c3ce 100644 --- a/clang/lib/Sema/SemaOverload.cpp +++ b/clang/lib/Sema/SemaOverload.cpp @@ -7036,7 +7036,6 @@ ExprResult Sema::PerformContextualImplicitConversion( if (Converter.match(T)) return Converted; - // FIXME: Check for missing '()' if T is a function type? // We can only perform contextual implicit conversions on objects of class _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
