llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Timm Baeder (tbaederr) <details> <summary>Changes</summary> For the test case in C, both `LV.getLValueOffset()` and `Ctx.getTypeSizeInChars(Ty)` are zero, so we return `true` from `isOnePastTheEndOfCompleteObject()` and ultimately diagnose this as being one past the end, but the diagnostic doesn't make sense. --- Full diff: https://github.com/llvm/llvm-project/pull/84293.diff 3 Files Affected: - (modified) clang/lib/AST/ExprConstant.cpp (+6-1) - (modified) clang/test/Sema/const-eval.c (+1-2) - (added) clang/test/Sema/constexpr-void-cast.c (+14) ``````````diff diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp index d8ca35740fbc35..bc8de9d08542cd 100644 --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -9211,7 +9211,8 @@ bool PointerExprEvaluator::VisitCastExpr(const CastExpr *E) { Info.getLangOpts().CPlusPlus26)) { // Permitted. } else { - if (SubExpr->getType()->isVoidPointerType()) { + if (SubExpr->getType()->isVoidPointerType() && + Info.getLangOpts().CPlusPlus) { if (HasValidResult) CCEDiag(E, diag::note_constexpr_invalid_void_star_cast) << SubExpr->getType() << Info.getLangOpts().CPlusPlus26 @@ -12899,6 +12900,10 @@ static bool isOnePastTheEndOfCompleteObject(const ASTContext &Ctx, if (Ty->isIncompleteType()) return true; + // Can't be past the end of an invalid object. + if (LV.getLValueDesignator().Invalid) + return false; + // We're a past-the-end pointer if we point to the byte after the object, // no matter what our type or path is. auto Size = Ctx.getTypeSizeInChars(Ty); diff --git a/clang/test/Sema/const-eval.c b/clang/test/Sema/const-eval.c index 2e38d5e23c208a..e358aceaad5a43 100644 --- a/clang/test/Sema/const-eval.c +++ b/clang/test/Sema/const-eval.c @@ -134,8 +134,7 @@ void PR21945(void) { int i = (({}), 0l); } void PR24622(void); struct PR24622 {} pr24622; -EVAL_EXPR(52, &pr24622 == (void *)&PR24622); // expected-error {{not an integer constant expression}} - // expected-note@-1 {{past the end}} +EVAL_EXPR(52, &pr24622 == (void *)&PR24622); // We evaluate these by providing 2s' complement semantics in constant // expressions, like we do for integers. diff --git a/clang/test/Sema/constexpr-void-cast.c b/clang/test/Sema/constexpr-void-cast.c new file mode 100644 index 00000000000000..c5caa3b9e58feb --- /dev/null +++ b/clang/test/Sema/constexpr-void-cast.c @@ -0,0 +1,14 @@ +// RUN: %clang_cc1 -x c -fsyntax-only %s -verify=c +// RUN: %clang_cc1 -x c -fsyntax-only %s -pedantic -verify=c-pedantic +// +// RUN: %clang_cc1 -x c++ -fsyntax-only %s -verify=cxx +// RUN: %clang_cc1 -x c++ -fsyntax-only %s -pedantic -verify=cxx-pedantic + +// c-no-diagnostics +// cxx-no-diagnostics + +void f(void); +struct S {char c;} s; +_Static_assert(&s != (void *)&f, ""); // c-pedantic-warning {{not an integer constant expression}} \ + // c-pedantic-note {{this conversion is not allowed in a constant expression}} \ + // cxx-pedantic-warning {{'_Static_assert' is a C11 extension}} `````````` </details> https://github.com/llvm/llvm-project/pull/84293 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
