Author: Haojian Wu Date: 2020-12-10T10:12:15+01:00 New Revision: a0539298540e49cb734c7b82f93572ab46bf9b00
URL: https://github.com/llvm/llvm-project/commit/a0539298540e49cb734c7b82f93572ab46bf9b00 DIFF: https://github.com/llvm/llvm-project/commit/a0539298540e49cb734c7b82f93572ab46bf9b00.diff LOG: [AST] Fix a constexpr-evaluator crash on error-dependent returnstmt. When the evaluator encounters an error-dependent returnstmt, before this patch it returned a ESR_Returned without setting the result, the callsides think this is a successful execution, and try to access the Result which causes the crash. The fix is to always return failed as we don't know the result of the error-dependent return stmt. Differential Revision: https://reviews.llvm.org/D92969 Added: Modified: clang/lib/AST/ExprConstant.cpp clang/test/SemaCXX/constexpr-function-recovery-crash.cpp Removed: ################################################################################ diff --git a/clang/lib/AST/ExprConstant.cpp b/clang/lib/AST/ExprConstant.cpp index fc1d2cd7757e..0865b8b85138 100644 --- a/clang/lib/AST/ExprConstant.cpp +++ b/clang/lib/AST/ExprConstant.cpp @@ -5142,8 +5142,11 @@ static EvalStmtResult EvaluateStmt(StmtResult &Result, EvalInfo &Info, case Stmt::ReturnStmtClass: { const Expr *RetExpr = cast<ReturnStmt>(S)->getRetValue(); FullExpressionRAII Scope(Info); - if (RetExpr && RetExpr->isValueDependent()) - return EvaluateDependentExpr(RetExpr, Info) ? ESR_Returned : ESR_Failed; + if (RetExpr && RetExpr->isValueDependent()) { + EvaluateDependentExpr(RetExpr, Info); + // We know we returned, but we don't know what the value is. + return ESR_Failed; + } if (RetExpr && !(Result.Slot ? EvaluateInPlace(Result.Value, Info, *Result.Slot, RetExpr) diff --git a/clang/test/SemaCXX/constexpr-function-recovery-crash.cpp b/clang/test/SemaCXX/constexpr-function-recovery-crash.cpp index 48a0d97619e4..94be9a12bc66 100644 --- a/clang/test/SemaCXX/constexpr-function-recovery-crash.cpp +++ b/clang/test/SemaCXX/constexpr-function-recovery-crash.cpp @@ -66,3 +66,6 @@ template<int x> constexpr int f(int y) { // expected-note {{candidate template i constexpr int test9(int x) { return f<1>(f<x>(1)); // expected-error {{no matching function for call to 'f'}} } + +constexpr int test10() { return undef(); } // expected-error {{use of undeclared identifier 'undef'}} +static_assert(test10() <= 1, "should not crash"); // expected-error {{static_assert expression is not an integral constant expression}} _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
