llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-clang Author: Discookie (Discookie) <details> <summary>Changes</summary> Relands #<!-- -->129502. Previously when the framework encountered unsupported values (such as enum classes), they were always treated as equal when comparing with `==`, regardless of their actual values being different. Now the two sides are only equal if there's a Value assigned to them. Added handling for the special case of `nullptr == nullptr`, to preserve the behavior of untyped `nullptr` having no value. --- Full diff: https://github.com/llvm/llvm-project/pull/131575.diff 2 Files Affected: - (modified) clang/lib/Analysis/FlowSensitive/Transfer.cpp (+8-1) - (modified) clang/unittests/Analysis/FlowSensitive/TransferTest.cpp (+35) ``````````diff diff --git a/clang/lib/Analysis/FlowSensitive/Transfer.cpp b/clang/lib/Analysis/FlowSensitive/Transfer.cpp index 9c54eb16d2224..6403190723e69 100644 --- a/clang/lib/Analysis/FlowSensitive/Transfer.cpp +++ b/clang/lib/Analysis/FlowSensitive/Transfer.cpp @@ -60,7 +60,14 @@ static BoolValue &evaluateBooleanEquality(const Expr &LHS, const Expr &RHS, Value *LHSValue = Env.getValue(LHS); Value *RHSValue = Env.getValue(RHS); - if (LHSValue == RHSValue) + // When two unsupported values are compared, both are nullptr. Only supported + // values should evaluate to equal. + if (LHSValue == RHSValue && LHSValue) + return Env.getBoolLiteralValue(true); + + // Special case: `NullPtrLiteralExpr == itself`. When both sides are untyped + // nullptr, they do not have an assigned Value, but they compare equal. + if (LHS.getType()->isNullPtrType() && RHS.getType()->isNullPtrType()) return Env.getBoolLiteralValue(true); if (auto *LHSBool = dyn_cast_or_null<BoolValue>(LHSValue)) diff --git a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp index 0f731f4532535..f52b73dbbdc57 100644 --- a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp +++ b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp @@ -4974,6 +4974,41 @@ TEST(TransferTest, IntegerLiteralEquality) { }); } +TEST(TransferTest, UnsupportedValueEquality) { + std::string Code = R"( + // An explicitly unsupported type by the framework. + enum class EC { + A, + B + }; + + void target() { + EC ec = EC::A; + + bool unsupported_eq_same = (EC::A == EC::A); + bool unsupported_eq_other = (EC::A == EC::B); + bool unsupported_eq_var = (ec == EC::B); + + (void)0; // [[p]] + } + )"; + runDataflow( + Code, + [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results, + ASTContext &ASTCtx) { + const Environment &Env = getEnvironmentAtAnnotation(Results, "p"); + + // We do not model the values of unsupported types, so this + // seemingly-trivial case will not be true either. + EXPECT_TRUE(isa<AtomicBoolValue>( + getValueForDecl<BoolValue>(ASTCtx, Env, "unsupported_eq_same"))); + EXPECT_TRUE(isa<AtomicBoolValue>( + getValueForDecl<BoolValue>(ASTCtx, Env, "unsupported_eq_other"))); + EXPECT_TRUE(isa<AtomicBoolValue>( + getValueForDecl<BoolValue>(ASTCtx, Env, "unsupported_eq_var"))); + }); +} + TEST(TransferTest, CorrelatedBranches) { std::string Code = R"( void target(bool B, bool C) { `````````` </details> https://github.com/llvm/llvm-project/pull/131575 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
