[clang][dataflow] Fix SAT solver crashes on `X ^ X` and `X v X`

BooleanFormula::addClause has an invariant that a clause has no duplicated
literals. When the solver was desugaring a formula into CNF clauses, it
could construct a clause with such duplicated literals in two cases.

Reviewed By: sgatev, ymandel, xazax.hun

Differential Revision: https://reviews.llvm.org/D130522

1 files changed, 19 insertions, 1 deletions

diff --git a/clang/unittests/Analysis/FlowSensitive/SolverTest.cpp b/clang/unittests/Analysis/FlowSensitive/SolverTest.cpp
index 3bb7ace..0c50c19 100644
--- a/clang/unittests/Analysis/FlowSensitive/SolverTest.cpp
+++ b/clang/unittests/Analysis/FlowSensitive/SolverTest.cpp
@@ -120,7 +120,7 @@ TEST(SolverTest, NegatedConjunction) {
   expectUnsatisfiable(solve({NotXAndY, XAndY}));
 }
 
-TEST(SolverTest, DisjunctionSameVars) {
+TEST(SolverTest, DisjunctionSameVarWithNegation) {
   ConstraintContext Ctx;
   auto X = Ctx.atom();
   auto NotX = Ctx.neg(X);
@@ -130,6 +130,15 @@ TEST(SolverTest, DisjunctionSameVars) {
   expectSatisfiable(solve({XOrNotX}), _);
 }
 
+TEST(SolverTest, DisjunctionSameVar) {
+  ConstraintContext Ctx;
+  auto X = Ctx.atom();
+  auto XOrX = Ctx.disj(X, X);
+
+  // X v X
+  expectSatisfiable(solve({XOrX}), _);
+}
+
 TEST(SolverTest, ConjunctionSameVarsConflict) {
   ConstraintContext Ctx;
   auto X = Ctx.atom();
@@ -140,6 +149,15 @@ TEST(SolverTest, ConjunctionSameVarsConflict) {
   expectUnsatisfiable(solve({XAndNotX}));
 }
 
+TEST(SolverTest, ConjunctionSameVar) {
+  ConstraintContext Ctx;
+  auto X = Ctx.atom();
+  auto XAndX = Ctx.conj(X, X);
+
+  // X ^ X
+  expectSatisfiable(solve({XAndX}), _);
+}
+
 TEST(SolverTest, PureVar) {
   ConstraintContext Ctx;
   auto X = Ctx.atom();