https://github.com/NeKon69 created https://github.com/llvm/llvm-project/pull/190345
`throw` is a special case: it produces void, but it can still appear in the ternary operator. Ignore it when flowing origins. Closes #183895 >From 813689c7f7392ec5c44d90ec8a030a9ba102985d Mon Sep 17 00:00:00 2001 From: NeKon69 <[email protected]> Date: Fri, 3 Apr 2026 16:32:34 +0300 Subject: [PATCH 1/3] [LifetimeSafety] Apply the fix --- .../Analysis/LifetimeSafety/FactsGenerator.cpp | 18 ++++++++++++++++-- 1 file changed, 16 insertions(+), 2 deletions(-) diff --git a/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp b/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp index 75f2978d848b7..6108d34275092 100644 --- a/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp +++ b/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp @@ -94,6 +94,10 @@ static const Loan *createLoan(FactManager &FactMgr, return FactMgr.getLoanMgr().createLoan(Path, MTE); } +static bool producesConditionalResult(const Expr *E) { + return isa<CXXThrowExpr>(E->IgnoreParenImpCasts()); +} + void FactsGenerator::run() { llvm::TimeTraceScope TimeProfile("FactGenerator"); const CFG &Cfg = *AC.getCFG(); @@ -404,8 +408,18 @@ void FactsGenerator::VisitConditionalOperator(const ConditionalOperator *CO) { if (hasOrigins(CO)) { // Merge origins from both branches of the conditional operator. // We kill to clear the initial state and merge both origins into it. - killAndFlowOrigin(*CO, *CO->getTrueExpr()); - flowOrigin(*CO, *CO->getFalseExpr()); + const Expr *TrueExpr = CO->getTrueExpr(); + const Expr *FalseExpr = CO->getFalseExpr(); + bool Initialized = false; + for (const Expr *Branch : {TrueExpr, FalseExpr}) { + if (producesConditionalResult(Branch)) + continue; + if (!Initialized) { + killAndFlowOrigin(*CO, *Branch); + Initialized = true; + } else + flowOrigin(*CO, *Branch); + } } } >From c43162e8d4de5a033ddc84a275f6fe3a44db78f7 Mon Sep 17 00:00:00 2001 From: NeKon69 <[email protected]> Date: Fri, 3 Apr 2026 16:41:36 +0300 Subject: [PATCH 2/3] add a test file --- .../test/Sema/warn-lifetime-safety-conditional-throw.cpp | 9 +++++++++ 1 file changed, 9 insertions(+) create mode 100644 clang/test/Sema/warn-lifetime-safety-conditional-throw.cpp diff --git a/clang/test/Sema/warn-lifetime-safety-conditional-throw.cpp b/clang/test/Sema/warn-lifetime-safety-conditional-throw.cpp new file mode 100644 index 0000000000000..2437618d131cd --- /dev/null +++ b/clang/test/Sema/warn-lifetime-safety-conditional-throw.cpp @@ -0,0 +1,9 @@ +// RUN: %clang_cc1 -fsyntax-only -fcxx-exceptions -Wlifetime-safety -Wno-dangling -verify %s + +// expected-no-diagnostics + +void conditional_throw_branches(bool cond, int *value) { + (void)(cond ? throw 1 : value); + (void)(cond ? value : throw 1); + (void)(cond ? throw 1 : throw 2); +} >From ac67df326082b1a1ed7237742789b85bafaff45e Mon Sep 17 00:00:00 2001 From: NeKon69 <[email protected]> Date: Fri, 3 Apr 2026 16:43:14 +0300 Subject: [PATCH 3/3] update functions body to represent what it actually does --- clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp b/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp index 6108d34275092..5eb2fcd150576 100644 --- a/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp +++ b/clang/lib/Analysis/LifetimeSafety/FactsGenerator.cpp @@ -95,7 +95,7 @@ static const Loan *createLoan(FactManager &FactMgr, } static bool producesConditionalResult(const Expr *E) { - return isa<CXXThrowExpr>(E->IgnoreParenImpCasts()); + return !isa<CXXThrowExpr>(E->IgnoreParenImpCasts()); } void FactsGenerator::run() { @@ -412,7 +412,7 @@ void FactsGenerator::VisitConditionalOperator(const ConditionalOperator *CO) { const Expr *FalseExpr = CO->getFalseExpr(); bool Initialized = false; for (const Expr *Branch : {TrueExpr, FalseExpr}) { - if (producesConditionalResult(Branch)) + if (!producesConditionalResult(Branch)) continue; if (!Initialized) { killAndFlowOrigin(*CO, *Branch); _______________________________________________ cfe-commits mailing list [email protected] https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
