diff --git a/clang/lib/Analysis/FlowSensitive/Transfer.cpp b/clang/lib/Analysis/FlowSensitive/Transfer.cpp --- a/clang/lib/Analysis/FlowSensitive/Transfer.cpp +++ b/clang/lib/Analysis/FlowSensitive/Transfer.cpp @@ -21,6 +21,7 @@ #include "clang/AST/Stmt.h" #include "clang/AST/StmtVisitor.h" #include "clang/Analysis/FlowSensitive/DataflowEnvironment.h" +#include "clang/Analysis/FlowSensitive/Value.h" #include "clang/Basic/OperatorKinds.h" #include "llvm/ADT/STLExtras.h" #include "llvm/Support/Casting.h" @@ -37,6 +38,26 @@ return E; } +static BoolValue &evaluateBooleanEquality(const Expr &LHS, const Expr &RHS, + Environment &Env) { + // Equality of booleans involves implicit integral casts. Ignore these casts + // for now and focus on the values associated with the wrapped expressions. + // FIXME: Consider changing this once the framework offers better support for + // integral casts. + const Expr *LHSNorm = LHS.IgnoreCasts(); + const Expr *RHSNorm = RHS.IgnoreCasts(); + assert(LHSNorm != nullptr); + assert(RHSNorm != nullptr); + + if (auto *LHSValue = dyn_cast_or_null( + Env.getValue(*LHSNorm, SkipPast::Reference))) + if (auto *RHSValue = dyn_cast_or_null( + Env.getValue(*RHSNorm, SkipPast::Reference))) + return Env.makeIff(*LHSValue, *RHSValue); + + return Env.makeAtomicBoolValue(); +} + class TransferVisitor : public ConstStmtVisitor { public: TransferVisitor(const StmtToEnvMap &StmtToEnv, Environment &Env) @@ -83,8 +104,16 @@ Env.setValue(Loc, Env.makeOr(LHSVal, RHSVal)); break; } + case BO_NE: + case BO_EQ: { + auto &LHSEqRHSValue = evaluateBooleanEquality(*LHS, *RHS, Env); + auto &Loc = Env.createStorageLocation(*S); + Env.setStorageLocation(*S, Loc); + Env.setValue(Loc, S->getOpcode() == BO_EQ ? LHSEqRHSValue + : Env.makeNot(LHSEqRHSValue)); + break; + } default: - // FIXME: Add support for BO_EQ, BO_NE. break; } } diff --git a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp --- a/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp +++ b/clang/unittests/Analysis/FlowSensitive/TransferTest.cpp @@ -2578,4 +2578,74 @@ }); } +TEST_F(TransferTest, BooleanEquality) { + std::string Code = R"( + void target(bool Bar) { + bool Foo = true; + if (Bar == Foo) { + (void)0; + /*[[p-then]]*/ + } else { + (void)0; + /*[[p-else]]*/ + } + } + )"; + runDataflow( + Code, [](llvm::ArrayRef< + std::pair>> + Results, + ASTContext &ASTCtx) { + ASSERT_THAT(Results, ElementsAre(Pair("p-else", _), Pair("p-then", _))); + const Environment &EnvElse = Results[0].second.Env; + const Environment &EnvThen = Results[1].second.Env; + + const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar"); + ASSERT_THAT(BarDecl, NotNull()); + + auto &BarValThen = + *cast(EnvThen.getValue(*BarDecl, SkipPast::None)); + EXPECT_TRUE(EnvThen.flowConditionImplies(BarValThen)); + + auto &BarValElse = + *cast(EnvElse.getValue(*BarDecl, SkipPast::None)); + EXPECT_FALSE(EnvElse.flowConditionImplies(BarValElse)); + }); +} + +TEST_F(TransferTest, BooleanInequality) { + std::string Code = R"( + void target(bool Bar) { + bool Foo = true; + if (Bar != Foo) { + (void)0; + /*[[p-then]]*/ + } else { + (void)0; + /*[[p-else]]*/ + } + } + )"; + runDataflow( + Code, [](llvm::ArrayRef< + std::pair>> + Results, + ASTContext &ASTCtx) { + ASSERT_THAT(Results, ElementsAre(Pair("p-else", _), Pair("p-then", _))); + const Environment &EnvElse = Results[0].second.Env; + const Environment &EnvThen = Results[1].second.Env; + + const ValueDecl *BarDecl = findValueDecl(ASTCtx, "Bar"); + ASSERT_THAT(BarDecl, NotNull()); + + auto &BarValThen = + *cast(EnvThen.getValue(*BarDecl, SkipPast::None)); + EXPECT_FALSE(EnvThen.flowConditionImplies(BarValThen)); + + auto &BarValElse = + *cast(EnvElse.getValue(*BarDecl, SkipPast::None)); + EXPECT_TRUE(EnvElse.flowConditionImplies(BarValElse)); + }); +} + } // namespace