[ASTImport]CXXBoolLiteralExpr should be handled explicitly in statement comparation

In the comparation of return statement, return value(if it is
CXXBoolLiteralExpr) should be handled explicitly, otherwise an
incorrect result would be returned.

Reviewed By: steakhal, donat.nagy

Differential Revision: https://reviews.llvm.org/D159479

Author: jcsxky

clang/lib/AST/ASTStructuralEquivalence.cpp

@@ -366,6 +366,10 @@ class StmtComparer {
     return true;
   }
 
+  bool IsStmtEquivalent(const CXXBoolLiteralExpr *E1, const CXXBoolLiteralExpr *E2) {
+    return E1->getValue() == E2->getValue();
+  }
+
   /// End point of the traversal chain.
   bool TraverseStmt(const Stmt *S1, const Stmt *S2) { return true; }
 

clang/unittests/AST/StructuralEquivalenceTest.cpp

@@ -1798,6 +1798,25 @@ TEST_F(StructuralEquivalenceCacheTest, SimpleNonEq) {
       TU, cxxRecordDecl(hasName("B"), unless(isImplicit())))));
 }
 
+TEST_F(StructuralEquivalenceCacheTest, ReturnStmtNonEq) {
+  auto TU = makeTuDecls(
+      R"(
+      bool x(){ return true; }
+      )",
+      R"(
+      bool x(){ return false; }
+      )",
+      Lang_CXX03);
+
+  StructuralEquivalenceContext Ctx(
+      get<0>(TU)->getASTContext(), get<1>(TU)->getASTContext(),
+      NonEquivalentDecls, StructuralEquivalenceKind::Default, false, false);
+
+  auto X = findDeclPair<FunctionDecl>(TU, functionDecl(hasName("x")));
+  EXPECT_FALSE(Ctx.IsEquivalent(X.first->getBody(), X.second->getBody()));
+
+}
+
 TEST_F(StructuralEquivalenceCacheTest, SpecialNonEq) {
   auto TU = makeTuDecls(
       R"(