From 0d0478903474b2e53c874427e3d6eb2ed7567e50 Mon Sep 17 00:00:00 2001 From: Utkarsh Saxena Date: Tue, 22 Jul 2025 21:31:09 +0200 Subject: [PATCH] [LifetimeSafety] Add language option for experimental lifetime safety (#149592) Add a language option flag for experimental lifetime safety analysis in C++. This change provides a language option to control the experimental lifetime safety analysis feature, making it more explicit and easier to enable/disable. Previously, the feature was controlled indirectly through a diagnostic warning flag, which we do not want to accidentally enable with `-Weverything` (atm)! ### Changes: - Added a new language option `EnableLifetimeSafety` in `LangOptions.def` for experimental lifetime safety analysis in C++ - Added corresponding driver options `-fexperimental-lifetime-safety` and `-fno-experimental-lifetime-safety` in `Options.td` - Modified `AnalysisBasedWarnings.cpp` to use the new language option flag instead of checking if a specific diagnostic is ignored - Updated a test case to use the new flag instead of relying on the warning flag alone --- clang/include/clang/Basic/LangOptions.def | 2 ++ clang/include/clang/Driver/Options.td | 8 ++++++++ clang/lib/Sema/AnalysisBasedWarnings.cpp | 3 +-- clang/test/Sema/warn-lifetime-safety-dataflow.cpp | 2 +- 4 files changed, 12 insertions(+), 3 deletions(-) diff --git a/clang/include/clang/Basic/LangOptions.def b/clang/include/clang/Basic/LangOptions.def index 6ac8d496f149..08d98a77e025 100644 --- a/clang/include/clang/Basic/LangOptions.def +++ b/clang/include/clang/Basic/LangOptions.def @@ -491,6 +491,8 @@ LANGOPT(CheckConstexprFunctionBodies, 1, 1, Benign, LANGOPT(BoundsSafety, 1, 0, NotCompatible, "Bounds safety extension for C") +LANGOPT(EnableLifetimeSafety, 1, 0, NotCompatible, "Experimental lifetime safety analysis for C++") + LANGOPT(PreserveVec3Type, 1, 0, NotCompatible, "Preserve 3-component vector type") #undef LANGOPT diff --git a/clang/include/clang/Driver/Options.td b/clang/include/clang/Driver/Options.td index 97b2eb9c44a8..55e90b7a0048 100644 --- a/clang/include/clang/Driver/Options.td +++ b/clang/include/clang/Driver/Options.td @@ -1904,6 +1904,14 @@ defm bounds_safety : BoolFOption< BothFlags<[], [CC1Option], " experimental bounds safety extension for C">>; +defm lifetime_safety : BoolFOption< + "experimental-lifetime-safety", + LangOpts<"EnableLifetimeSafety">, DefaultFalse, + PosFlag, + NegFlag, + BothFlags<[], [CC1Option], + " experimental lifetime safety for C++">>; + defm addrsig : BoolFOption<"addrsig", CodeGenOpts<"Addrsig">, DefaultFalse, PosFlag, diff --git a/clang/lib/Sema/AnalysisBasedWarnings.cpp b/clang/lib/Sema/AnalysisBasedWarnings.cpp index d4d640bf988b..829c81bab16f 100644 --- a/clang/lib/Sema/AnalysisBasedWarnings.cpp +++ b/clang/lib/Sema/AnalysisBasedWarnings.cpp @@ -2901,8 +2901,7 @@ void clang::sema::AnalysisBasedWarnings::IssueWarnings( .setAlwaysAdd(Stmt::UnaryOperatorClass); } - bool EnableLifetimeSafetyAnalysis = !Diags.isIgnored( - diag::warn_experimental_lifetime_safety_dummy_warning, D->getBeginLoc()); + bool EnableLifetimeSafetyAnalysis = S.getLangOpts().EnableLifetimeSafety; // Install the logical handler. std::optional LEH; if (LogicalErrorHandler::hasActiveDiagnostics(Diags, D->getBeginLoc())) { diff --git a/clang/test/Sema/warn-lifetime-safety-dataflow.cpp b/clang/test/Sema/warn-lifetime-safety-dataflow.cpp index 0eb3bda918f8..2b934ac23b92 100644 --- a/clang/test/Sema/warn-lifetime-safety-dataflow.cpp +++ b/clang/test/Sema/warn-lifetime-safety-dataflow.cpp @@ -1,4 +1,4 @@ -// RUN: %clang_cc1 -mllvm -debug-only=LifetimeFacts -Wexperimental-lifetime-safety %s 2>&1 | FileCheck %s +// RUN: %clang_cc1 -fexperimental-lifetime-safety -mllvm -debug-only=LifetimeFacts -Wexperimental-lifetime-safety %s 2>&1 | FileCheck %s // REQUIRES: asserts struct MyObj {