[PATCH] D66538: [AST] AST structural equivalence to work internally with pairs.

[Gabor Marton via Phabricator via cfe-commits]

martong added a comment.

Ok.

I like this patch because it eliminates the need for checking the redeclaration chains.

Seems like it handles cycles and the simple `f(A,B)` vs `f(A,A)` cases properly too. (Not talking about caching now, probably we must remove the `NonEquivalentDecls` cache.)
I've added two new test cases, could you please add them to the patch (maybe with modifications if you find something)?

  TEST_F(StructuralEquivalenceCacheTest, Cycle) {
    auto Decls =
        makeTuDecls(
            R"(
              class C;
              class A { C *c; };
              class B {
                int i;
              };
              void x(A *);
              void y(A *);
              class C {
                friend void x(A *);
                friend void y(A *);
              };
            )",
            R"(
              class C;
              class A { C *c; };
              class B {
                int i;
              };
              void x(A *);
              void y(A *);
              class C {
                friend void x(A *);
                friend void y(A *);
              };
            )", Lang_CXX);
  
    TranslationUnitDecl *TU1 = get<0>(Decls);
    TranslationUnitDecl *TU2 = get<1>(Decls);
    auto *C1 = LastDeclMatcher<CXXRecordDecl>().match(
        TU1, cxxRecordDecl(hasName("C"), unless(isImplicit())));
    auto *C2 = LastDeclMatcher<CXXRecordDecl>().match(
        TU2, cxxRecordDecl(hasName("C"), unless(isImplicit())));
  
    llvm::DenseSet<std::pair<Decl *, Decl *>> NonEquivalentDecls;
    StructuralEquivalenceContext Ctx(
        C1->getASTContext(), C2->getASTContext(), NonEquivalentDecls,
        StructuralEquivalenceKind::Default, false, false);
    bool Eq = Ctx.IsEquivalent(C1, C2);
  
    EXPECT_TRUE(Eq);
  }
  
  TEST_F(StructuralEquivalenceCacheTest, SimpleNonEq) {
    auto Decls =
        makeTuDecls(
            R"(
              class A {};
              class B {};
              void x(A, A);
            )",
            R"(
              class A {};
              class B {};
              void x(A, B);
            )", Lang_CXX);
  
    TranslationUnitDecl *TU1 = get<0>(Decls);
    TranslationUnitDecl *TU2 = get<1>(Decls);
    auto *x1 =
        FirstDeclMatcher<FunctionDecl>().match(TU1, functionDecl(hasName("x")));
    auto *x2 =
        FirstDeclMatcher<FunctionDecl>().match(TU2, functionDecl(hasName("x")));
  
    llvm::DenseSet<std::pair<Decl *, Decl *>> NonEquivalentDecls;
    StructuralEquivalenceContext Ctx(
        x1->getASTContext(), x2->getASTContext(), NonEquivalentDecls,
        StructuralEquivalenceKind::Default, false, false);
    bool Eq = Ctx.IsEquivalent(x1, x2);
  
    EXPECT_FALSE(Eq);
  }


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D66538/new/

https://reviews.llvm.org/D66538