[clang][AST][ASTImporter] improve AST comparasion on VarDecl & GotoStmt

[jcsxky]

Summary

improve AST comparasion on VarDecl & GotoStmt:

1. VarDecl should not be ignored,
2. GotoStmt has no children, it should be handle explicitly.

[jcsxky]

update according to llvm convention.

[jcsxky]

ping～ @donat.nagy @steakhal @balazske

[donat.nagy]

LGTM. I'm not very familiar with this area, but the change seems to be a very clean improvement.

clang/lib/AST/ASTStructuralEquivalence.cpp

class StmtComparer {
   bool IsStmtEquivalent(const ObjCStringLiteral *E1,
                         const ObjCStringLiteral *E2) {
     // Just wraps a StringLiteral child.
     return true;
   }
 
   bool IsStmtEquivalent(const Stmt *S1, const Stmt *S2) { return true; }
 
+  bool IsStmtEquivalent(const GotoStmt *S1, const GotoStmt *S2) {
+    auto *L1 = S1->getLabel();
+    auto *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();
   }
 
   bool IsStmtEquivalent(const StmtExpr *E1, const StmtExpr *E2) {
     return E1->getTemplateDepth() == E2->getTemplateDepth();
   }
 
case Type::DependentBitInt: {
     break;
   }
   } // end switch
 
   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) {
   const auto *Owner2 = cast<Decl>(Field2->getDeclContext());
 
   // For anonymous structs/unions, match up the anonymous struct/union type
   // declarations directly, so that we don't go off searching for anonymous
   // types
   if (Field1->isAnonymousStructOrUnion() &&

clang/unittests/AST/StructuralEquivalenceTest.cpp

 #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"
 #include "clang/Testing/CommandLineArgs.h"
 #include "clang/Tooling/Tooling.h"
 #include "llvm/TargetParser/Host.h"
 
 #include "DeclMatcher.h"
EXPECT_FALSE(isInNonEqCache(findDeclPair<CXXRecordDecl>(
       TU, cxxRecordDecl(hasName("A"), unless(isImplicit())))));
   EXPECT_FALSE(isInNonEqCache(findDeclPair<CXXRecordDecl>(
       TU, cxxRecordDecl(hasName("B"), unless(isImplicit())))));
 }
 
 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);
 
   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, 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 X = findDeclPair<VarDecl>(TU, varDecl());
+  EXPECT_FALSE(Ctx.IsEquivalent(X.first, X.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 X = findDeclPair<VarDecl>(TU, varDecl());
+  EXPECT_FALSE(Ctx.IsEquivalent(X.first, X.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 X = findDeclPair<VarDecl>(TU, varDecl());
+  EXPECT_FALSE(Ctx.IsEquivalent(X.first, X.second));
+}
+
 TEST_F(StructuralEquivalenceCacheTest, SpecialNonEq) {
   auto TU = makeTuDecls(
       R"(
       class A {};
       class B { int i; };
       void x(A *);
       void y(A *);
       class C {
auto t = makeStmts(
       }
 
       void g() { f<char, int>(1); }
       )",
       Lang_CXX03, unresolvedLookupExpr());
   EXPECT_TRUE(testStructuralMatch(t));
 }
 
+TEST_F(StructuralEquivalenceCacheTest, GotoStmtNoEq) {
+  auto t = makeStmts(
+      R"(
+      void foo() {
+        goto L1;
+        L1: foo();
+      }
+      )",
+      R"(
+      void foo() {
+        goto L2;
+        L2: foo();
+      }
+      )",
+      Lang_CXX03, gotoStmt());
+  EXPECT_FALSE(testStructuralMatch(t));
+}
+
 } // end namespace ast_matchers
 } // end namespace clang