From 49573916f74d5e904eec2ed6989a0c5263dc21fc Mon Sep 17 00:00:00 2001 From: Balazs Benics Date: Tue, 5 Aug 2025 17:03:53 +0200 Subject: [PATCH 1/2] [analyzer] Drop assertion enforcing that assume args are known constants (#151908) We sometimes don't know if the operand of [[assume]] is true/false, and that's okay. We can just ignore the attribute in that case. If we wanted something more fancy, we could bring the assumption to the constraints, but dropping them should be just as fine for now. Fixes #151854 (cherry picked from commit 0a1eff2ecedcb11acb3e9d4b75ee1e1bebd69a70) --- clang/lib/StaticAnalyzer/Checkers/AssumeModeling.cpp | 1 - clang/test/Analysis/cxx23-assume-attribute.cpp | 5 +++++ 2 files changed, 5 insertions(+), 1 deletion(-) diff --git a/clang/lib/StaticAnalyzer/Checkers/AssumeModeling.cpp b/clang/lib/StaticAnalyzer/Checkers/AssumeModeling.cpp index 1e3adb4f266ca..789c7772d123a 100644 --- a/clang/lib/StaticAnalyzer/Checkers/AssumeModeling.cpp +++ b/clang/lib/StaticAnalyzer/Checkers/AssumeModeling.cpp @@ -45,7 +45,6 @@ void AssumeModelingChecker::checkPostStmt(const AttributedStmt *A, continue; const auto *Assumption = AssumptionVal.getAsInteger(); - assert(Assumption && "We should know the exact outcome of an assume expr"); if (Assumption && Assumption->isZero()) { C.addSink(); } diff --git a/clang/test/Analysis/cxx23-assume-attribute.cpp b/clang/test/Analysis/cxx23-assume-attribute.cpp index 86e7662cd2af9..dd15ff5d43505 100644 --- a/clang/test/Analysis/cxx23-assume-attribute.cpp +++ b/clang/test/Analysis/cxx23-assume-attribute.cpp @@ -69,3 +69,8 @@ int assume_and_fallthrough_at_the_same_attrstmt(int a, int b) { return 0; } + +void assume_opaque_gh151854_no_crash() { + extern bool opaque(); + [[assume(opaque())]]; // no-crash +} From d618b40e5e86132e0fa64ef0f3a5322fa96698b4 Mon Sep 17 00:00:00 2001 From: Balazs Benics Date: Tue, 5 Aug 2025 17:28:49 +0200 Subject: [PATCH 2/2] [analyzer] Add missing expected-warning after #151908 (cherry picked from commit 6c9f1ce429809e5a91683ed6cef9a435047bebd1) --- clang/test/Analysis/cxx23-assume-attribute.cpp | 1 + 1 file changed, 1 insertion(+) diff --git a/clang/test/Analysis/cxx23-assume-attribute.cpp b/clang/test/Analysis/cxx23-assume-attribute.cpp index dd15ff5d43505..4cc16446572dc 100644 --- a/clang/test/Analysis/cxx23-assume-attribute.cpp +++ b/clang/test/Analysis/cxx23-assume-attribute.cpp @@ -73,4 +73,5 @@ int assume_and_fallthrough_at_the_same_attrstmt(int a, int b) { void assume_opaque_gh151854_no_crash() { extern bool opaque(); [[assume(opaque())]]; // no-crash + // expected-warning@-1 {{assumption is ignored because it contains (potential) side-effects}} }