llvm-project/clang-tools-extra/clangd/unittests/ASTTests.cpp

//===-- ASTTests.cpp --------------------------------------------*- C++ -*-===//
//
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
//
//===----------------------------------------------------------------------===//

#include "AST.h"

#include "Annotations.h"
#include "ParsedAST.h"
#include "TestTU.h"
#include "clang/AST/Decl.h"
#include "clang/AST/DeclBase.h"
#include "clang/Basic/SourceManager.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/Support/Casting.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include <cstddef>
#include <string>
#include <vector>

namespace clang {
namespace clangd {
namespace {

TEST(GetDeducedType, KwAutoKwDecltypeExpansion) {
  struct Test {
    StringRef AnnotatedCode;
    const char *DeducedType;
  } Tests[] = {
      {"^auto i = 0;", "int"},
      {"^auto f(){ return 1;};", "int"},
      {
          R"cpp( // auto on struct in a namespace
              namespace ns1 { struct S {}; }
              ^auto v = ns1::S{};
          )cpp",
          "struct ns1::S",
      },
      {
          R"cpp( // decltype on struct
              namespace ns1 { struct S {}; }
              ns1::S i;
              ^decltype(i) j;
          )cpp",
          "ns1::S",
      },
      {
          R"cpp(// decltype(auto) on struct&
            namespace ns1 {
            struct S {};
            } // namespace ns1

            ns1::S i;
            ns1::S& j = i;
            ^decltype(auto) k = j;
          )cpp",
          "struct ns1::S &",
      },
      {
          R"cpp( // auto on template class
              class X;
              template<typename T> class Foo {};
              ^auto v = Foo<X>();
          )cpp",
          "class Foo<class X>",
      },
      {
          R"cpp( // auto on initializer list.
              namespace std
              {
                template<class _E>
                class [[initializer_list]] {};
              }

              ^auto i = {1,2};
          )cpp",
          "class std::initializer_list<int>",
      },
      {
          R"cpp( // auto in function return type with trailing return type
            struct Foo {};
            ^auto test() -> decltype(Foo()) {
              return Foo();
            }
          )cpp",
          "struct Foo",
      },
      {
          R"cpp( // decltype in trailing return type
            struct Foo {};
            auto test() -> ^decltype(Foo()) {
              return Foo();
            }
          )cpp",
          "struct Foo",
      },
      {
          R"cpp( // auto in function return type
            struct Foo {};
            ^auto test() {
              return Foo();
            }
          )cpp",
          "struct Foo",
      },
      {
          R"cpp( // auto& in function return type
            struct Foo {};
            ^auto& test() {
              static Foo x;
              return x;
            }
          )cpp",
          "struct Foo",
      },
      {
          R"cpp( // auto* in function return type
            struct Foo {};
            ^auto* test() {
              Foo *x;
              return x;
            }
          )cpp",
          "struct Foo",
      },
      {
          R"cpp( // const auto& in function return type
            struct Foo {};
            const ^auto& test() {
              static Foo x;
              return x;
            }
          )cpp",
          "struct Foo",
      },
      {
          R"cpp( // decltype(auto) in function return (value)
            struct Foo {};
            ^decltype(auto) test() {
              return Foo();
            }
          )cpp",
          "struct Foo",
      },
      {
          R"cpp( // decltype(auto) in function return (ref)
            struct Foo {};
            ^decltype(auto) test() {
              static Foo x;
              return (x);
            }
          )cpp",
          "struct Foo &",
      },
      {
          R"cpp( // decltype(auto) in function return (const ref)
            struct Foo {};
            ^decltype(auto) test() {
              static const Foo x;
              return (x);
            }
          )cpp",
          "const struct Foo &",
      },
      {
          R"cpp( // auto on alias
            struct Foo {};
            using Bar = Foo;
            ^auto x = Bar();
          )cpp",
          // FIXME: it'd be nice if this resolved to the alias instead
          "struct Foo",
      },
  };
  for (Test T : Tests) {
    Annotations File(T.AnnotatedCode);
    auto AST = TestTU::withCode(File.code()).build();
    SourceManagerForFile SM("foo.cpp", File.code());

    SCOPED_TRACE(File.code());
    EXPECT_FALSE(File.points().empty());
    for (Position Pos : File.points()) {
      auto Location = sourceLocationInMainFile(SM.get(), Pos);
      ASSERT_TRUE(!!Location) << llvm::toString(Location.takeError());
      auto DeducedType = getDeducedType(AST.getASTContext(), *Location);
      ASSERT_TRUE(DeducedType);
      EXPECT_EQ(DeducedType->getAsString(), T.DeducedType);
    }
  }
}

TEST(ClangdAST, GetQualification) {
  // Tries to insert the decl `Foo` into position of each decl named `insert`.
  // This is done to get an appropriate DeclContext for the insertion location.
  // Qualifications are the required nested name specifier to spell `Foo` at the
  // `insert`ion location.
  // VisibleNamespaces are assumed to be visible at every insertion location.
  const struct {
    llvm::StringRef Test;
    std::vector<llvm::StringRef> Qualifications;
    std::vector<std::string> VisibleNamespaces;
  } Cases[] = {
      {
          R"cpp(
            namespace ns1 { namespace ns2 { class Foo {}; } }
            void insert(); // ns1::ns2::Foo
            namespace ns1 {
              void insert(); // ns2::Foo
              namespace ns2 {
                void insert(); // Foo
              }
              using namespace ns2;
              void insert(); // Foo
            }
            using namespace ns1;
            void insert(); // ns2::Foo
            using namespace ns2;
            void insert(); // Foo
          )cpp",
          {"ns1::ns2::", "ns2::", "", "", "ns2::", ""},
          {},
      },
      {
          R"cpp(
            namespace ns1 { namespace ns2 { class Bar { void Foo(); }; } }
            void insert(); // ns1::ns2::Bar::Foo
            namespace ns1 {
              void insert(); // ns2::Bar::Foo
              namespace ns2 {
                void insert(); // Bar::Foo
              }
              using namespace ns2;
              void insert(); // Bar::Foo
            }
            using namespace ns1;
            void insert(); // ns2::Bar::Foo
            using namespace ns2;
            void insert(); // Bar::Foo
          )cpp",
          {"ns1::ns2::Bar::", "ns2::Bar::", "Bar::", "Bar::", "ns2::Bar::",
           "Bar::"},
          {},
      },
      {
          R"cpp(
            namespace ns1 { namespace ns2 { void Foo(); } }
            void insert(); // ns2::Foo
            namespace ns1 {
              void insert(); // ns2::Foo
              namespace ns2 {
                void insert(); // Foo
              }
            }
          )cpp",
          {"ns2::", "ns2::", ""},
          {"ns1::"},
      },
  };
  for (const auto &Case : Cases) {
    Annotations Test(Case.Test);
    TestTU TU = TestTU::withCode(Test.code());
    ParsedAST AST = TU.build();
    std::vector<const Decl *> InsertionPoints;
    const NamedDecl *TargetDecl;
    findDecl(AST, [&](const NamedDecl &ND) {
      if (ND.getNameAsString() == "Foo") {
        TargetDecl = &ND;
        return true;
      }

      if (ND.getNameAsString() == "insert")
        InsertionPoints.push_back(&ND);
      return false;
    });

    ASSERT_EQ(InsertionPoints.size(), Case.Qualifications.size());
    for (size_t I = 0, E = InsertionPoints.size(); I != E; ++I) {
      const Decl *D = InsertionPoints[I];
      if (Case.VisibleNamespaces.empty()) {
        EXPECT_EQ(getQualification(AST.getASTContext(),
                                   D->getLexicalDeclContext(), D->getBeginLoc(),
                                   TargetDecl),
                  Case.Qualifications[I]);
      } else {
        EXPECT_EQ(getQualification(AST.getASTContext(),
                                   D->getLexicalDeclContext(), TargetDecl,
                                   Case.VisibleNamespaces),
                  Case.Qualifications[I]);
      }
    }
  }
}

TEST(ClangdAST, PrintType) {
  const struct {
    llvm::StringRef Test;
    std::vector<llvm::StringRef> Types;
  } Cases[] = {
      {
          R"cpp(
            namespace ns1 { namespace ns2 { class Foo {}; } }
            void insert(); // ns1::ns2::Foo
            namespace ns1 {
              void insert(); // ns2::Foo
              namespace ns2 {
                void insert(); // Foo
              }
            }
          )cpp",
          {"ns1::ns2::Foo", "ns2::Foo", "Foo"},
      },
      {
          R"cpp(
            namespace ns1 {
              typedef int Foo;
            }
            void insert(); // ns1::Foo
            namespace ns1 {
              void insert(); // Foo
            }
          )cpp",
          {"ns1::Foo", "Foo"},
      },
  };
  for (const auto &Case : Cases) {
    Annotations Test(Case.Test);
    TestTU TU = TestTU::withCode(Test.code());
    ParsedAST AST = TU.build();
    std::vector<const DeclContext *> InsertionPoints;
    const TypeDecl *TargetDecl = nullptr;
    findDecl(AST, [&](const NamedDecl &ND) {
      if (ND.getNameAsString() == "Foo") {
        if (const auto *TD = llvm::dyn_cast<TypeDecl>(&ND)) {
          TargetDecl = TD;
          return true;
        }
      } else if (ND.getNameAsString() == "insert")
        InsertionPoints.push_back(ND.getDeclContext());
      return false;
    });

    ASSERT_EQ(InsertionPoints.size(), Case.Types.size());
    for (size_t I = 0, E = InsertionPoints.size(); I != E; ++I) {
      const auto *DC = InsertionPoints[I];
      EXPECT_EQ(printType(AST.getASTContext().getTypeDeclType(TargetDecl), *DC),
                Case.Types[I]);
    }
  }
}

TEST(ClangdAST, IsDeeplyNested) {
  Annotations Test(
      R"cpp(
        namespace ns {
        class Foo {
          void bar() {
            class Bar {};
          }
        };
        })cpp");
  TestTU TU = TestTU::withCode(Test.code());
  ParsedAST AST = TU.build();

  EXPECT_TRUE(isDeeplyNested(&findUnqualifiedDecl(AST, "Foo"), /*MaxDepth=*/1));
  EXPECT_FALSE(
      isDeeplyNested(&findUnqualifiedDecl(AST, "Foo"), /*MaxDepth=*/2));

  EXPECT_TRUE(isDeeplyNested(&findUnqualifiedDecl(AST, "bar"), /*MaxDepth=*/2));
  EXPECT_FALSE(
      isDeeplyNested(&findUnqualifiedDecl(AST, "bar"), /*MaxDepth=*/3));

  EXPECT_TRUE(isDeeplyNested(&findUnqualifiedDecl(AST, "Bar"), /*MaxDepth=*/3));
  EXPECT_FALSE(
      isDeeplyNested(&findUnqualifiedDecl(AST, "Bar"), /*MaxDepth=*/4));
}
} // namespace
} // namespace clangd
} // namespace clang