[clang] [clang][dataflow] Model conditional operator correctly. (PR #89213)

[Yitzhak Mandelbaum via cfe-commits]

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@@ -5243,6 +5243,67 @@ TEST(TransferTest, BinaryOperatorComma) {
       });
 }
 
+TEST(TransferTest, ConditionalOperatorValue) {
+  std::string Code = R"(
+    void target(bool Cond, bool B1, bool B2) {
+      bool JoinSame = Cond ? B1 : B1;
+      bool JoinDifferent = Cond ? B1 : B2;
+      // [[p]]
+    }
+  )";
+  runDataflow(
+      Code,
+      [](const llvm::StringMap<DataflowAnalysisState<NoopLattice>> &Results,
+         ASTContext &ASTCtx) {
+        Environment Env = getEnvironmentAtAnnotation(Results, "p").fork();
+
+        auto &B1 = getValueForDecl<BoolValue>(ASTCtx, Env, "B1");
+        auto &B2 = getValueForDecl<BoolValue>(ASTCtx, Env, "B2");
+        auto &JoinSame = getValueForDecl<BoolValue>(ASTCtx, Env, "JoinSame");
+        auto &JoinDifferent =
+            getValueForDecl<BoolValue>(ASTCtx, Env, "JoinDifferent");
+
+        EXPECT_EQ(&JoinSame, &B1);
+
+        const Formula &JoinDifferentEqB1 =
+            Env.arena().makeEquals(JoinDifferent.formula(), B1.formula());
+        EXPECT_TRUE(Env.allows(JoinDifferentEqB1));
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ymand wrote:

Nice use of `allows`!

https://github.com/llvm/llvm-project/pull/89213