Author: Adam Czachorowski Date: 2022-07-14T15:45:32+02:00 New Revision: cab3cfd013cf92c441c3acbfcc1844b267ab8659
URL: https://github.com/llvm/llvm-project/commit/cab3cfd013cf92c441c3acbfcc1844b267ab8659 DIFF: https://github.com/llvm/llvm-project/commit/cab3cfd013cf92c441c3acbfcc1844b267ab8659.diff LOG: [clang] Do not crash on "requires" after a fatal error occurred. The code would assume that SubstExpr() cannot fail on concept specialization. This is incorret - we give up on some things after fatal error occurred, since there's no value in doing futher work that the user will not see anyway. In this case, this lead to crash. The fatal error is simulated in tests with -ferror-limit=1, but this could happen in other cases too. Fixes https://github.com/llvm/llvm-project/issues/55401 Differential Revision: https://reviews.llvm.org/D129499 Added: clang/test/SemaCXX/concept-fatal-error.cpp Modified: clang/lib/Sema/SemaExprCXX.cpp Removed: ################################################################################ diff --git a/clang/lib/Sema/SemaExprCXX.cpp b/clang/lib/Sema/SemaExprCXX.cpp index 11f33c7c63633..5331193de863d 100644 --- a/clang/lib/Sema/SemaExprCXX.cpp +++ b/clang/lib/Sema/SemaExprCXX.cpp @@ -9006,14 +9006,14 @@ Sema::BuildExprRequirement( cast<TemplateTypeParmDecl>(TPL->getParam(0))->getTypeConstraint() ->getImmediatelyDeclaredConstraint(); ExprResult Constraint = SubstExpr(IDC, MLTAL); - assert(!Constraint.isInvalid() && - "Substitution cannot fail as it is simply putting a type template " - "argument into a concept specialization expression's parameter."); - - SubstitutedConstraintExpr = - cast<ConceptSpecializationExpr>(Constraint.get()); - if (!SubstitutedConstraintExpr->isSatisfied()) - Status = concepts::ExprRequirement::SS_ConstraintsNotSatisfied; + if (Constraint.isInvalid()) { + Status = concepts::ExprRequirement::SS_ExprSubstitutionFailure; + } else { + SubstitutedConstraintExpr = + cast<ConceptSpecializationExpr>(Constraint.get()); + if (!SubstitutedConstraintExpr->isSatisfied()) + Status = concepts::ExprRequirement::SS_ConstraintsNotSatisfied; + } } return new (Context) concepts::ExprRequirement(E, IsSimple, NoexceptLoc, ReturnTypeRequirement, Status, diff --git a/clang/test/SemaCXX/concept-fatal-error.cpp b/clang/test/SemaCXX/concept-fatal-error.cpp new file mode 100644 index 0000000000000..c299b39fdeb23 --- /dev/null +++ b/clang/test/SemaCXX/concept-fatal-error.cpp @@ -0,0 +1,10 @@ +// RUN: not %clang_cc1 -fsyntax-only -std=c++20 -ferror-limit 1 -verify %s + +template <class> +concept f = requires { 42; }; +struct h { + // The missing semicolon will trigger an error and -ferror-limit=1 will make it fatal + // We test that we do not crash in such cases (#55401) + int i = requires { { i } f } // expected-error {{expected ';' at end of declaration list}} + // expected-error@* {{too many errros emitted}} +}; _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
