Author: Takuya Shimizu Date: 2023-09-18T18:14:44+09:00 New Revision: b2cd9db589335d5885c04df83003a623cf2f05ff
URL: https://github.com/llvm/llvm-project/commit/b2cd9db589335d5885c04df83003a623cf2f05ff DIFF: https://github.com/llvm/llvm-project/commit/b2cd9db589335d5885c04df83003a623cf2f05ff.diff LOG: [clang][Sema] Remove irrelevant diagnostics from constraint satisfaction failure BEFORE this patch, when clang handles constraints like C1 || C2 where C1 evaluates to false and C2 evaluates to true, it emitted irrelevant diagnostics about the falsity of C1. This patch removes the irrelevant diagnostic information generated during the evaluation of C1 if C2 evaluates to true. Fixes https://github.com/llvm/llvm-project/issues/54678 Reviewed By: erichkeane Differential Revision: https://reviews.llvm.org/D157526 Added: Modified: clang/docs/ReleaseNotes.rst clang/lib/Sema/SemaConcept.cpp clang/test/SemaTemplate/concepts.cpp Removed: ################################################################################ diff --git a/clang/docs/ReleaseNotes.rst b/clang/docs/ReleaseNotes.rst index d47d664c062c204..500f9c9a0cda741 100644 --- a/clang/docs/ReleaseNotes.rst +++ b/clang/docs/ReleaseNotes.rst @@ -169,6 +169,9 @@ Improvements to Clang's diagnostics Also clang no longer emits false positive warnings about the output length of ``%g`` format specifier and about ``%o, %x, %X`` with ``#`` flag. - Clang now emits ``-Wcast-qual`` for functional-style cast expressions. +- Clang no longer emits irrelevant notes about unsatisfied constraint expressions + on the left-hand side of ``||`` when the right-hand side constraint is satisfied. + (`#54678: <https://github.com/llvm/llvm-project/issues/54678>`_). Bug Fixes in This Version ------------------------- diff --git a/clang/lib/Sema/SemaConcept.cpp b/clang/lib/Sema/SemaConcept.cpp index d1fa8e7831225b7..dacdd07c8069950 100644 --- a/clang/lib/Sema/SemaConcept.cpp +++ b/clang/lib/Sema/SemaConcept.cpp @@ -185,6 +185,7 @@ calculateConstraintSatisfaction(Sema &S, const Expr *ConstraintExpr, ConstraintExpr = ConstraintExpr->IgnoreParenImpCasts(); if (LogicalBinOp BO = ConstraintExpr) { + auto EffectiveDetailEnd = Satisfaction.Details.end(); ExprResult LHSRes = calculateConstraintSatisfaction( S, BO.getLHS(), Satisfaction, Evaluator); @@ -218,6 +219,19 @@ calculateConstraintSatisfaction(Sema &S, const Expr *ConstraintExpr, if (RHSRes.isInvalid()) return ExprError(); + bool IsRHSSatisfied = Satisfaction.IsSatisfied; + // Current implementation adds diagnostic information about the falsity + // of each false atomic constraint expression when it evaluates them. + // When the evaluation results to `false || true`, the information + // generated during the evaluation of left-hand side is meaningless + // because the whole expression evaluates to true. + // The following code removes the irrelevant diagnostic information. + // FIXME: We should probably delay the addition of diagnostic information + // until we know the entire expression is false. + if (BO.isOr() && IsRHSSatisfied) + Satisfaction.Details.erase(EffectiveDetailEnd, + Satisfaction.Details.end()); + return BO.recreateBinOp(S, LHSRes, RHSRes); } diff --git a/clang/test/SemaTemplate/concepts.cpp b/clang/test/SemaTemplate/concepts.cpp index 9776ddbb372991e..891b45aa5789296 100644 --- a/clang/test/SemaTemplate/concepts.cpp +++ b/clang/test/SemaTemplate/concepts.cpp @@ -994,3 +994,40 @@ void test_params() { } } + +namespace GH54678 { +template<class> +concept True = true; + +template<class> +concept False = false; // expected-note 9 {{'false' evaluated to false}} + +template<class> +concept Irrelevant = false; + +template <typename T> +concept ErrorRequires = requires(ErrorRequires auto x) { x; }; // expected-error {{unknown type name 'ErrorRequires'}} + +template<class T> void aaa(T t) // expected-note {{candidate template ignored: constraints not satisfied}} +requires (False<T> || False<T>) || False<T> {} // expected-note 3 {{'int' does not satisfy 'False'}} +template<class T> void bbb(T t) // expected-note {{candidate template ignored: constraints not satisfied}} +requires (False<T> || False<T>) && True<T> {} // expected-note 2 {{'long' does not satisfy 'False'}} +template<class T> void ccc(T t) // expected-note {{candidate template ignored: constraints not satisfied}} +requires (True<T> || Irrelevant<T>) && False<T> {} // expected-note {{'unsigned long' does not satisfy 'False'}} +template<class T> void ddd(T t) // expected-note {{candidate template ignored: constraints not satisfied}} +requires (Irrelevant<T> || True<T>) && False<T> {} // expected-note {{'int' does not satisfy 'False'}} +template<class T> void eee(T t) // expected-note {{candidate template ignored: constraints not satisfied}} +requires (Irrelevant<T> || Irrelevant<T> || True<T>) && False<T> {} // expected-note {{'long' does not satisfy 'False'}} + +template<class T> void fff(T t) // expected-note {{candidate template ignored: constraints not satisfied}} +requires((ErrorRequires<T> || False<T> || True<T>) && False<T>) {} // expected-note {{'unsigned long' does not satisfy 'False'}} + +void test() { + aaa(42); // expected-error {{no matching function}} + bbb(42L); // expected-error{{no matching function}} + ccc(42UL); // expected-error {{no matching function}} + ddd(42); // expected-error {{no matching function}} + eee(42L); // expected-error {{no matching function}} + fff(42UL); // expected-error {{no matching function}} +} +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits