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[clang][dataflow] Remove DataflowAnalysisContext::flowConditionIsTautology(). (#69601)

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It's only used in its own unit tests.
This commit is contained in:
martinboehme
2023-10-23 08:18:12 +02:00
committed by GitHub
parent 0374bbba4c
commit 3eed23d31c
3 changed files with 0 additions and 40 deletions
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4
clang/include/clang/Analysis/FlowSensitive/DataflowAnalysisContext.h
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@@ -133,10 +133,6 @@ public:
/// identified by `Token` imply that `Val` is true.
bool flowConditionImplies(Atom Token, const Formula &);
/// Returns true if and only if the constraints of the flow condition
/// identified by `Token` are always true.
bool flowConditionIsTautology(Atom Token);
/// Returns true if `Val1` is equivalent to `Val2`.
/// Note: This function doesn't take into account constraints on `Val1` and
/// `Val2` imposed by the flow condition.

9
clang/lib/Analysis/FlowSensitive/DataflowAnalysisContext.cpp
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@@ -158,15 +158,6 @@ bool DataflowAnalysisContext::flowConditionImplies(Atom Token,
return isUnsatisfiable(std::move(Constraints));
}
bool DataflowAnalysisContext::flowConditionIsTautology(Atom Token) {
// Returns true if and only if we cannot prove that the flow condition can
// ever be false.
llvm::SetVector<const Formula *> Constraints;
Constraints.insert(&arena().makeNot(arena().makeAtomRef(Token)));
addTransitiveFlowConditionConstraints(Token, Constraints);
return isUnsatisfiable(std::move(Constraints));
}
bool DataflowAnalysisContext::equivalentFormulas(const Formula &Val1,
const Formula &Val2) {
llvm::SetVector<const Formula *> Constraints;

27
clang/unittests/Analysis/FlowSensitive/DataflowAnalysisContextTest.cpp
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@@ -99,33 +99,6 @@ TEST_F(DataflowAnalysisContextTest, JoinFlowConditions) {
EXPECT_TRUE(Context.flowConditionImplies(FC3, C3));
}
TEST_F(DataflowAnalysisContextTest, FlowConditionTautologies) {
// Fresh flow condition with empty/no constraints is always true.
Atom FC1 = A.makeFlowConditionToken();
EXPECT_TRUE(Context.flowConditionIsTautology(FC1));
// Literal `true` is always true.
Atom FC2 = A.makeFlowConditionToken();
Context.addFlowConditionConstraint(FC2, A.makeLiteral(true));
EXPECT_TRUE(Context.flowConditionIsTautology(FC2));
// Literal `false` is never true.
Atom FC3 = A.makeFlowConditionToken();
Context.addFlowConditionConstraint(FC3, A.makeLiteral(false));
EXPECT_FALSE(Context.flowConditionIsTautology(FC3));
// We can't prove that an arbitrary bool A is always true...
auto &C1 = A.makeAtomRef(A.makeAtom());
Atom FC4 = A.makeFlowConditionToken();
Context.addFlowConditionConstraint(FC4, C1);
EXPECT_FALSE(Context.flowConditionIsTautology(FC4));
// ... but we can prove A || !A is true.
Atom FC5 = A.makeFlowConditionToken();
Context.addFlowConditionConstraint(FC5, A.makeOr(C1, A.makeNot(C1)));
EXPECT_TRUE(Context.flowConditionIsTautology(FC5));
}
TEST_F(DataflowAnalysisContextTest, EquivBoolVals) {
auto &X = A.makeAtomRef(A.makeAtom());
auto &Y = A.makeAtomRef(A.makeAtom());