Author: Paulo Matos Date: 2022-01-12T16:10:58+01:00 New Revision: 968be05b8fdc1d23c055cc4963230a89efbc5967
URL: https://github.com/llvm/llvm-project/commit/968be05b8fdc1d23c055cc4963230a89efbc5967 DIFF: https://github.com/llvm/llvm-project/commit/968be05b8fdc1d23c055cc4963230a89efbc5967.diff LOG: [clang] Fix crash for sizeof on VLAs Adds overload of TransformToPotentiallyEvaluated for TypeSourceInfo to properly deal with VLAs in nested calls of sizeof and typeof. Fixes PR31042 (https://github.com/llvm/llvm-project/issues/30390). Reviewed By: efriedma Differential Revision: https://reviews.llvm.org/D27800 Added: clang/test/SemaCXX/pr31042.cpp Modified: clang/include/clang/Sema/Sema.h clang/lib/Sema/SemaExpr.cpp Removed: ################################################################################ diff --git a/clang/include/clang/Sema/Sema.h b/clang/include/clang/Sema/Sema.h index f1e90356c8367..b4d8d1494e705 100644 --- a/clang/include/clang/Sema/Sema.h +++ b/clang/include/clang/Sema/Sema.h @@ -5053,6 +5053,7 @@ class Sema final { void DiscardCleanupsInEvaluationContext(); ExprResult TransformToPotentiallyEvaluated(Expr *E); + TypeSourceInfo *TransformToPotentiallyEvaluated(TypeSourceInfo *TInfo); ExprResult HandleExprEvaluationContextForTypeof(Expr *E); ExprResult CheckUnevaluatedOperand(Expr *E); diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp index 229a604901244..7de43705c2b10 100644 --- a/clang/lib/Sema/SemaExpr.cpp +++ b/clang/lib/Sema/SemaExpr.cpp @@ -4499,6 +4499,10 @@ Sema::CreateUnaryExprOrTypeTraitExpr(TypeSourceInfo *TInfo, } // C99 6.5.3.4p4: the type (an unsigned integer type) is size_t. + if (isUnevaluatedContext() && ExprKind == UETT_SizeOf && + TInfo->getType()->isVariablyModifiedType()) + TInfo = TransformToPotentiallyEvaluated(TInfo); + return new (Context) UnaryExprOrTypeTraitExpr( ExprKind, TInfo, Context.getSizeType(), OpLoc, R.getEnd()); } @@ -16601,6 +16605,16 @@ ExprResult Sema::TransformToPotentiallyEvaluated(Expr *E) { return TransformToPE(*this).TransformExpr(E); } +TypeSourceInfo *Sema::TransformToPotentiallyEvaluated(TypeSourceInfo *TInfo) { + assert(isUnevaluatedContext() && + "Should only transform unevaluated expressions"); + ExprEvalContexts.back().Context = + ExprEvalContexts[ExprEvalContexts.size() - 2].Context; + if (isUnevaluatedContext()) + return TInfo; + return TransformToPE(*this).TransformType(TInfo); +} + void Sema::PushExpressionEvaluationContext( ExpressionEvaluationContext NewContext, Decl *LambdaContextDecl, diff --git a/clang/test/SemaCXX/pr31042.cpp b/clang/test/SemaCXX/pr31042.cpp new file mode 100644 index 0000000000000..d4995c6e4d686 --- /dev/null +++ b/clang/test/SemaCXX/pr31042.cpp @@ -0,0 +1,10 @@ +// RUN: %clang_cc1 -o - -emit-llvm -triple x86_64-unknown-linux-gnu -disable-free %s +// We need to use -emit-llvm in order to trigger the error, without it semantic analysis +// does not verify the used bit and there's no error. + +char a[1]; + +void f1(void) { + int i = 0; + int j = sizeof(typeof(*(char(*)[i])a)); +} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits