llvm-project/clang/unittests/AST/ASTTraverserTest.cpp

//===- unittests/AST/ASTTraverserTest.h------------------------------------===//
//
// 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 "clang/AST/ASTContext.h"
#include "clang/AST/ASTNodeTraverser.h"
#include "clang/AST/TextNodeDumper.h"
#include "clang/ASTMatchers/ASTMatchFinder.h"
#include "clang/ASTMatchers/ASTMatchers.h"
#include "clang/Tooling/Tooling.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"

using namespace clang::tooling;
using namespace clang::ast_matchers;

namespace clang {

class NodeTreePrinter : public TextTreeStructure {
  llvm::raw_ostream &OS;

public:
  NodeTreePrinter(llvm::raw_ostream &OS)
      : TextTreeStructure(OS, /* showColors */ false), OS(OS) {}

  void Visit(const Decl *D) {
    OS << D->getDeclKindName() << "Decl";
    if (auto *ND = dyn_cast<NamedDecl>(D)) {
      OS << " '" << ND->getDeclName() << "'";
    }
  }

  void Visit(const Stmt *S) {
    OS << S->getStmtClassName();
    if (auto *E = dyn_cast<DeclRefExpr>(S)) {
      OS << " '" << E->getDecl()->getDeclName() << "'";
    }
  }

  void Visit(QualType QT) {
    OS << "QualType " << QT.split().Quals.getAsString();
  }

  void Visit(const Type *T) { OS << T->getTypeClassName() << "Type"; }

  void Visit(const comments::Comment *C, const comments::FullComment *FC) {
    OS << C->getCommentKindName();
  }

  void Visit(const CXXCtorInitializer *Init) { OS << "CXXCtorInitializer"; }

  void Visit(const Attr *A) {
    switch (A->getKind()) {
#define ATTR(X)                                                                \
  case attr::X:                                                                \
    OS << #X;                                                                  \
    break;
#include "clang/Basic/AttrList.inc"
    }
    OS << "Attr";
  }

  void Visit(const OMPClause *C) { OS << "OMPClause"; }
  void Visit(const TemplateArgument &A, SourceRange R = {},
             const Decl *From = nullptr, const char *Label = nullptr) {
    OS << "TemplateArgument";
  }

  template <typename... T> void Visit(T...) {}
};

class TestASTDumper : public ASTNodeTraverser<TestASTDumper, NodeTreePrinter> {

  NodeTreePrinter MyNodeRecorder;

public:
  TestASTDumper(llvm::raw_ostream &OS) : MyNodeRecorder(OS) {}
  NodeTreePrinter &doGetNodeDelegate() { return MyNodeRecorder; }
};

template <typename... NodeType> std::string dumpASTString(NodeType &&... N) {
  std::string Buffer;
  llvm::raw_string_ostream OS(Buffer);

  TestASTDumper Dumper(OS);

  OS << "\n";

  Dumper.Visit(std::forward<NodeType &&>(N)...);

  return OS.str();
}

template <typename... NodeType>
std::string dumpASTString(TraversalKind TK, NodeType &&... N) {
  std::string Buffer;
  llvm::raw_string_ostream OS(Buffer);

  TestASTDumper Dumper(OS);
  Dumper.SetTraversalKind(TK);

  OS << "\n";

  Dumper.Visit(std::forward<NodeType &&>(N)...);

  return OS.str();
}

const FunctionDecl *getFunctionNode(clang::ASTUnit *AST,
                                    const std::string &Name) {
  auto Result = ast_matchers::match(functionDecl(hasName(Name)).bind("fn"),
                                    AST->getASTContext());
  EXPECT_EQ(Result.size(), 1u);
  return Result[0].getNodeAs<FunctionDecl>("fn");
}

template <typename T> struct Verifier {
  static void withDynNode(T Node, const std::string &DumpString) {
    EXPECT_EQ(dumpASTString(DynTypedNode::create(Node)), DumpString);
  }
};

template <typename T> struct Verifier<T *> {
  static void withDynNode(T *Node, const std::string &DumpString) {
    EXPECT_EQ(dumpASTString(DynTypedNode::create(*Node)), DumpString);
  }
};

template <typename T>
void verifyWithDynNode(T Node, const std::string &DumpString) {
  EXPECT_EQ(dumpASTString(Node), DumpString);

  Verifier<T>::withDynNode(Node, DumpString);
}

TEST(Traverse, Dump) {

  auto AST = buildASTFromCode(R"cpp(
struct A {
  int m_number;

  /// CTor
  A() : m_number(42) {}

  [[nodiscard]] const int func() {
    return 42;
  }

};

template<typename T>
struct templ
{
};

template<>
struct templ<int>
{
};

void parmvardecl_attr(struct A __attribute__((address_space(19)))*);

)cpp");

  const FunctionDecl *Func = getFunctionNode(AST.get(), "func");

  verifyWithDynNode(Func,
                    R"cpp(
CXXMethodDecl 'func'
|-CompoundStmt
| `-ReturnStmt
|   `-IntegerLiteral
`-WarnUnusedResultAttr
)cpp");

  Stmt *Body = Func->getBody();

  verifyWithDynNode(Body,
                    R"cpp(
CompoundStmt
`-ReturnStmt
  `-IntegerLiteral
)cpp");

  QualType QT = Func->getType();

  verifyWithDynNode(QT,
                    R"cpp(
FunctionProtoType
`-QualType const
  `-BuiltinType
)cpp");

  const FunctionDecl *CTorFunc = getFunctionNode(AST.get(), "A");

  verifyWithDynNode(CTorFunc->getType(),
                    R"cpp(
FunctionProtoType
`-BuiltinType
)cpp");

  Attr *A = *Func->attr_begin();

  {
    std::string expectedString = R"cpp(
WarnUnusedResultAttr
)cpp";

    EXPECT_EQ(dumpASTString(A), expectedString);
  }

  auto *CTor = dyn_cast<CXXConstructorDecl>(CTorFunc);
  const CXXCtorInitializer *Init = *CTor->init_begin();

  verifyWithDynNode(Init,
                    R"cpp(
CXXCtorInitializer
`-IntegerLiteral
)cpp");

  const comments::FullComment *Comment =
      AST->getASTContext().getLocalCommentForDeclUncached(CTorFunc);
  {
    std::string expectedString = R"cpp(
FullComment
`-ParagraphComment
  `-TextComment
)cpp";
    EXPECT_EQ(dumpASTString(Comment, Comment), expectedString);
  }

  auto Result = ast_matchers::match(
      classTemplateSpecializationDecl(hasName("templ")).bind("fn"),
      AST->getASTContext());
  EXPECT_EQ(Result.size(), 1u);
  auto Templ = Result[0].getNodeAs<ClassTemplateSpecializationDecl>("fn");

  TemplateArgument TA = Templ->getTemplateArgs()[0];

  verifyWithDynNode(TA,
                    R"cpp(
TemplateArgument
)cpp");

  Func = getFunctionNode(AST.get(), "parmvardecl_attr");

  const auto *Parm = Func->getParamDecl(0);
  const auto TL = Parm->getTypeSourceInfo()->getTypeLoc();
  ASSERT_TRUE(TL.getType()->isPointerType());

  const auto ATL = TL.getNextTypeLoc().getAs<AttributedTypeLoc>();
  const auto *AS = cast<AddressSpaceAttr>(ATL.getAttr());
  EXPECT_EQ(toTargetAddressSpace(static_cast<LangAS>(AS->getAddressSpace())),
            19u);
}

TEST(Traverse, IgnoreUnlessSpelledInSourceStructs) {
  auto AST = buildASTFromCode(R"cpp(

struct MyStruct {
  MyStruct();
  MyStruct(int i) {
    MyStruct();
  }
  ~MyStruct();
};

)cpp");

  auto BN = ast_matchers::match(
      cxxConstructorDecl(hasName("MyStruct"),
                         hasParameter(0, parmVarDecl(hasType(isInteger()))))
          .bind("ctor"),
      AST->getASTContext());
  EXPECT_EQ(BN.size(), 1u);

  EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource,
                          BN[0].getNodeAs<Decl>("ctor")),
            R"cpp(
CXXConstructorDecl 'MyStruct'
|-ParmVarDecl 'i'
`-CompoundStmt
  `-CXXTemporaryObjectExpr
)cpp");

  EXPECT_EQ(dumpASTString(TK_AsIs, BN[0].getNodeAs<Decl>("ctor")),
            R"cpp(
CXXConstructorDecl 'MyStruct'
|-ParmVarDecl 'i'
`-CompoundStmt
  `-ExprWithCleanups
    `-CXXBindTemporaryExpr
      `-CXXTemporaryObjectExpr
)cpp");
}

TEST(Traverse, IgnoreUnlessSpelledInSourceReturnStruct) {

  auto AST = buildASTFromCode(R"cpp(
struct Retval {
  Retval() {}
  ~Retval() {}
};

Retval someFun();

void foo()
{
    someFun();
}
)cpp");

  auto BN = ast_matchers::match(functionDecl(hasName("foo")).bind("fn"),
                                AST->getASTContext());
  EXPECT_EQ(BN.size(), 1u);

  EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource,
                          BN[0].getNodeAs<Decl>("fn")),
            R"cpp(
FunctionDecl 'foo'
`-CompoundStmt
  `-CallExpr
    `-DeclRefExpr 'someFun'
)cpp");

  EXPECT_EQ(dumpASTString(TK_AsIs, BN[0].getNodeAs<Decl>("fn")),
            R"cpp(
FunctionDecl 'foo'
`-CompoundStmt
  `-ExprWithCleanups
    `-CXXBindTemporaryExpr
      `-CallExpr
        `-ImplicitCastExpr
          `-DeclRefExpr 'someFun'
)cpp");
}

TEST(Traverse, IgnoreUnlessSpelledInSourceReturns) {

  auto AST = buildASTFromCode(R"cpp(

struct A
{
};

struct B
{
  B(int);
  B(A const& a);
  B();
};

struct C
{
  operator B();
};

B func1() {
  return 42;
}

B func2() {
  return B{42};
}

B func3() {
  return B(42);
}

B func4() {
  return B();
}

B func5() {
  return B{};
}

B func6() {
  return C();
}

B func7() {
  return A();
}

B func8() {
  return C{};
}

B func9() {
  return A{};
}

B func10() {
  A a;
  return a;
}

B func11() {
  B b;
  return b;
}

B func12() {
  C c;
  return c;
}

)cpp");

  auto getFunctionNode = [&AST](const std::string &name) {
    auto BN = ast_matchers::match(functionDecl(hasName(name)).bind("fn"),
                                  AST->getASTContext());
    EXPECT_EQ(BN.size(), 1u);
    return BN[0].getNodeAs<Decl>("fn");
  };

  {
    auto FN = getFunctionNode("func1");
    llvm::StringRef Expected = R"cpp(
FunctionDecl 'func1'
`-CompoundStmt
  `-ReturnStmt
    `-ExprWithCleanups
      `-CXXConstructExpr
        `-MaterializeTemporaryExpr
          `-ImplicitCastExpr
            `-CXXConstructExpr
              `-IntegerLiteral
)cpp";

    EXPECT_EQ(dumpASTString(TK_AsIs, FN), Expected);

    Expected = R"cpp(
FunctionDecl 'func1'
`-CompoundStmt
  `-ReturnStmt
    `-IntegerLiteral
)cpp";
    EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource, FN), Expected);
  }

  llvm::StringRef Expected = R"cpp(
FunctionDecl 'func2'
`-CompoundStmt
  `-ReturnStmt
    `-CXXTemporaryObjectExpr
      `-IntegerLiteral
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func2")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func3'
`-CompoundStmt
  `-ReturnStmt
    `-CXXFunctionalCastExpr
      `-IntegerLiteral
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func3")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func4'
`-CompoundStmt
  `-ReturnStmt
    `-CXXTemporaryObjectExpr
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func4")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func5'
`-CompoundStmt
  `-ReturnStmt
    `-CXXTemporaryObjectExpr
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func5")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func6'
`-CompoundStmt
  `-ReturnStmt
    `-CXXTemporaryObjectExpr
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func6")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func7'
`-CompoundStmt
  `-ReturnStmt
    `-CXXTemporaryObjectExpr
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func7")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func8'
`-CompoundStmt
  `-ReturnStmt
    `-CXXFunctionalCastExpr
      `-InitListExpr
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func8")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func9'
`-CompoundStmt
  `-ReturnStmt
    `-CXXFunctionalCastExpr
      `-InitListExpr
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func9")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func10'
`-CompoundStmt
  |-DeclStmt
  | `-VarDecl 'a'
  |   `-CXXConstructExpr
  `-ReturnStmt
    `-DeclRefExpr 'a'
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func10")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func11'
`-CompoundStmt
  |-DeclStmt
  | `-VarDecl 'b'
  |   `-CXXConstructExpr
  `-ReturnStmt
    `-DeclRefExpr 'b'
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func11")),
      Expected);

  Expected = R"cpp(
FunctionDecl 'func12'
`-CompoundStmt
  |-DeclStmt
  | `-VarDecl 'c'
  |   `-CXXConstructExpr
  `-ReturnStmt
    `-DeclRefExpr 'c'
)cpp";
  EXPECT_EQ(
      dumpASTString(TK_IgnoreUnlessSpelledInSource, getFunctionNode("func12")),
      Expected);
}

TEST(Traverse, LambdaUnlessSpelledInSource) {

  auto AST =
      buildASTFromCodeWithArgs(R"cpp(

void captures() {
  int a = 0;
  int b = 0;
  int d = 0;
  int f = 0;

  [a, &b, c = d, &e = f](int g, int h = 42) {};
}

void templated() {
  int a = 0;
  [a]<typename T>(T t) {};
}

struct SomeStruct {
    int a = 0;
    void capture_this() {
        [this]() {};
    }
    void capture_this_copy() {
        [self = *this]() {};
    }
};
)cpp",
                               {"-Wno-unused-value", "-Wno-c++2a-extensions"});

  auto getLambdaNode = [&AST](const std::string &name) {
    auto BN = ast_matchers::match(
        lambdaExpr(hasAncestor(functionDecl(hasName(name)))).bind("lambda"),
        AST->getASTContext());
    EXPECT_EQ(BN.size(), 1u);
    return BN[0].getNodeAs<LambdaExpr>("lambda");
  };

  {
    auto L = getLambdaNode("captures");

    llvm::StringRef Expected = R"cpp(
LambdaExpr
|-DeclRefExpr 'a'
|-DeclRefExpr 'b'
|-VarDecl 'c'
| `-DeclRefExpr 'd'
|-VarDecl 'e'
| `-DeclRefExpr 'f'
|-ParmVarDecl 'g'
|-ParmVarDecl 'h'
| `-IntegerLiteral
`-CompoundStmt
)cpp";
    EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource, L), Expected);

    Expected = R"cpp(
LambdaExpr
|-CXXRecordDecl ''
| |-CXXMethodDecl 'operator()'
| | |-ParmVarDecl 'g'
| | |-ParmVarDecl 'h'
| | | `-IntegerLiteral
| | `-CompoundStmt
| |-FieldDecl ''
| |-FieldDecl ''
| |-FieldDecl ''
| |-FieldDecl ''
| `-CXXDestructorDecl '~'
|-ImplicitCastExpr
| `-DeclRefExpr 'a'
|-DeclRefExpr 'b'
|-ImplicitCastExpr
| `-DeclRefExpr 'd'
|-DeclRefExpr 'f'
`-CompoundStmt
)cpp";
    EXPECT_EQ(dumpASTString(TK_AsIs, L), Expected);
  }

  {
    auto L = getLambdaNode("templated");

    llvm::StringRef Expected = R"cpp(
LambdaExpr
|-DeclRefExpr 'a'
|-TemplateTypeParmDecl 'T'
|-ParmVarDecl 't'
`-CompoundStmt
)cpp";
    EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource, L), Expected);
  }

  {
    auto L = getLambdaNode("capture_this");

    llvm::StringRef Expected = R"cpp(
LambdaExpr
|-CXXThisExpr
`-CompoundStmt
)cpp";
    EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource, L), Expected);
  }

  {
    auto L = getLambdaNode("capture_this_copy");

    llvm::StringRef Expected = R"cpp(
LambdaExpr
|-VarDecl 'self'
| `-UnaryOperator
|   `-CXXThisExpr
`-CompoundStmt
)cpp";
    EXPECT_EQ(dumpASTString(TK_IgnoreUnlessSpelledInSource, L), Expected);
  }
}

} // namespace clang