[clang][AST][ASTImporter] improve AST comparasion on VarDecl & GotoStmt (#66976)

improve AST comparasion on VarDecl & GotoStmt:
  1. VarDecl should not be ignored,
  2. GotoStmt has no children, it should be handle explicitly.

Reviewed By: donat.nagy

Differential Revision: https://reviews.llvm.org/D159519

Co-authored-by: huqizhi <[email protected]>

Author: jcsxky

clang/lib/AST/ASTStructuralEquivalence.cpp

@@ -277,6 +277,17 @@ class StmtComparer {
 
   bool IsStmtEquivalent(const Stmt *S1, const Stmt *S2) { return true; }
 
+  bool IsStmtEquivalent(const GotoStmt *S1, const GotoStmt *S2) {
+    LabelDecl *L1 = S1->getLabel();
+    LabelDecl *L2 = S2->getLabel();
+    if (!L1 || !L2)
+      return L1 == L2;
+
+    IdentifierInfo *Name1 = L1->getIdentifier();
+    IdentifierInfo *Name2 = L2->getIdentifier();
+    return ::IsStructurallyEquivalent(Name1, Name2);
+  }
+
   bool IsStmtEquivalent(const SourceLocExpr *E1, const SourceLocExpr *E2) {
     return E1->getIdentKind() == E2->getIdentKind();
   }
@@ -1295,6 +1306,22 @@ static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
   return true;
 }
 
+static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
+                                     VarDecl *D1, VarDecl *D2) {
+  if (D1->getStorageClass() != D2->getStorageClass())
+    return false;
+
+  IdentifierInfo *Name1 = D1->getIdentifier();
+  IdentifierInfo *Name2 = D2->getIdentifier();
+  if (!::IsStructurallyEquivalent(Name1, Name2))
+    return false;
+
+  if (!IsStructurallyEquivalent(Context, D1->getType(), D2->getType()))
+    return false;
+
+  return IsStructurallyEquivalent(Context, D1->getInit(), D2->getInit());
+}
+
 static bool IsStructurallyEquivalent(StructuralEquivalenceContext &Context,
                                      FieldDecl *Field1, FieldDecl *Field2,
                                      QualType Owner2Type) {

clang/unittests/AST/StructuralEquivalenceTest.cpp

@@ -1,5 +1,6 @@
 #include "clang/AST/ASTContext.h"
 #include "clang/AST/ASTStructuralEquivalence.h"
+#include "clang/AST/Decl.h"
 #include "clang/AST/DeclTemplate.h"
 #include "clang/ASTMatchers/ASTMatchers.h"
 #include "clang/Frontend/ASTUnit.h"
@@ -1801,10 +1802,10 @@ TEST_F(StructuralEquivalenceCacheTest, SimpleNonEq) {
 TEST_F(StructuralEquivalenceCacheTest, ReturnStmtNonEq) {
   auto TU = makeTuDecls(
       R"(
-      bool x(){ return true; }
+      bool x() { return true; }
       )",
       R"(
-      bool x(){ return false; }
+      bool x() { return false; }
       )",
       Lang_CXX03);
 
@@ -1817,6 +1818,60 @@ TEST_F(StructuralEquivalenceCacheTest, ReturnStmtNonEq) {
 
 }
 
+TEST_F(StructuralEquivalenceCacheTest, VarDeclNoEq) {
+  auto TU = makeTuDecls(
+      R"(
+      int p;
+      )",
+      R"(
+      int q;
+      )",
+      Lang_CXX03);
+
+  StructuralEquivalenceContext Ctx(
+      get<0>(TU)->getASTContext(), get<1>(TU)->getASTContext(),
+      NonEquivalentDecls, StructuralEquivalenceKind::Default, false, false);
+
+  auto Var = findDeclPair<VarDecl>(TU, varDecl());
+  EXPECT_FALSE(Ctx.IsEquivalent(Var.first, Var.second));
+}
+
+TEST_F(StructuralEquivalenceCacheTest, VarDeclWithDifferentStorageClassNoEq) {
+  auto TU = makeTuDecls(
+      R"(
+      int p;
+      )",
+      R"(
+      static int p;
+      )",
+      Lang_CXX03);
+
+  StructuralEquivalenceContext Ctx(
+      get<0>(TU)->getASTContext(), get<1>(TU)->getASTContext(),
+      NonEquivalentDecls, StructuralEquivalenceKind::Default, false, false);
+
+  auto Var = findDeclPair<VarDecl>(TU, varDecl());
+  EXPECT_FALSE(Ctx.IsEquivalent(Var.first, Var.second));
+}
+
+TEST_F(StructuralEquivalenceCacheTest, VarDeclWithInitNoEq) {
+  auto TU = makeTuDecls(
+      R"(
+      int p = 1;
+      )",
+      R"(
+      int p = 2;
+      )",
+      Lang_CXX03);
+
+  StructuralEquivalenceContext Ctx(
+      get<0>(TU)->getASTContext(), get<1>(TU)->getASTContext(),
+      NonEquivalentDecls, StructuralEquivalenceKind::Default, false, false);
+
+  auto Var = findDeclPair<VarDecl>(TU, varDecl());
+  EXPECT_FALSE(Ctx.IsEquivalent(Var.first, Var.second));
+}
+
 TEST_F(StructuralEquivalenceCacheTest, SpecialNonEq) {
   auto TU = makeTuDecls(
       R"(
@@ -2320,5 +2375,23 @@ TEST_F(StructuralEquivalenceStmtTest, UnresolvedLookup) {
   EXPECT_TRUE(testStructuralMatch(t));
 }
 
+TEST_F(StructuralEquivalenceCacheTest, GotoStmtNoEq) {
+  auto S = makeStmts(
+      R"(
+      void foo() {
+        goto L1;
+        L1: foo();
+      }
+      )",
+      R"(
+      void foo() {
+        goto L2;
+        L2: foo();
+      }
+      )",
+      Lang_CXX03, gotoStmt());
+  EXPECT_FALSE(testStructuralMatch(S));
+}
+
 } // end namespace ast_matchers
 } // end namespace clang