//===- unittest/Tooling/LexicallyOrderedRecursiveASTVisitorTest.cpp -------===//
//
// 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 "TestVisitor.h"
#include "clang/AST/LexicallyOrderedRecursiveASTVisitor.h"
#include <stack>

using namespace clang;

namespace {

class DummyMatchVisitor;

class LexicallyOrderedDeclVisitor
    : public LexicallyOrderedRecursiveASTVisitor<LexicallyOrderedDeclVisitor> {
public:
  LexicallyOrderedDeclVisitor(DummyMatchVisitor &Matcher,
                              const SourceManager &SM, bool EmitDeclIndices,
                              bool EmitStmtIndices)
      : LexicallyOrderedRecursiveASTVisitor(SM), Matcher(Matcher),
        EmitDeclIndices(EmitDeclIndices), EmitStmtIndices(EmitStmtIndices) {}

  bool TraverseDecl(Decl *D) {
    TraversalStack.push_back(D);
    LexicallyOrderedRecursiveASTVisitor::TraverseDecl(D);
    TraversalStack.pop_back();
    return true;
  }

  bool TraverseStmt(Stmt *S);

  bool VisitNamedDecl(const NamedDecl *D);
  bool VisitDeclRefExpr(const DeclRefExpr *D);

private:
  DummyMatchVisitor &Matcher;
  bool EmitDeclIndices, EmitStmtIndices;
  unsigned Index = 0;
  llvm::SmallVector<Decl *, 8> TraversalStack;
};

class DummyMatchVisitor : public ExpectedLocationVisitor {
  bool EmitDeclIndices, EmitStmtIndices;

public:
  DummyMatchVisitor(bool EmitDeclIndices = false, bool EmitStmtIndices = false)
      : EmitDeclIndices(EmitDeclIndices), EmitStmtIndices(EmitStmtIndices) {}

  bool VisitTranslationUnitDecl(TranslationUnitDecl *TU) override {
    const ASTContext &Context = TU->getASTContext();
    const SourceManager &SM = Context.getSourceManager();
    LexicallyOrderedDeclVisitor SubVisitor(*this, SM, EmitDeclIndices,
                                           EmitStmtIndices);
    SubVisitor.TraverseDecl(TU);
    return false;
  }

  template <class T> void match(StringRef Path, const T *D) {
    Match(Path, D->getBeginLoc());
  }
};

bool LexicallyOrderedDeclVisitor::TraverseStmt(Stmt *S) {
  Matcher.match("overridden TraverseStmt", S);
  return LexicallyOrderedRecursiveASTVisitor::TraverseStmt(S);
}

bool LexicallyOrderedDeclVisitor::VisitNamedDecl(const NamedDecl *D) {
  std::string Path;
  llvm::raw_string_ostream OS(Path);
  assert(TraversalStack.back() == D);
  for (const Decl *D : TraversalStack) {
    if (isa<TranslationUnitDecl>(D)) {
      OS << "/";
      continue;
    }
    if (const auto *ND = dyn_cast<NamedDecl>(D))
      OS << ND->getNameAsString();
    else
      OS << "???";
    if (isa<DeclContext>(D) || isa<TemplateDecl>(D))
      OS << "/";
  }
  if (EmitDeclIndices)
    OS << "@" << Index++;
  Matcher.match(Path, D);
  return true;
}

bool LexicallyOrderedDeclVisitor::VisitDeclRefExpr(const DeclRefExpr *D) {
  std::string Name = D->getFoundDecl()->getNameAsString();
  llvm::raw_string_ostream OS(Name);
  if (EmitStmtIndices)
    OS << "@" << Index++;
  Matcher.match(Name, D);
  return true;
}

TEST(LexicallyOrderedRecursiveASTVisitor, VisitDeclsInImplementation) {
  StringRef Source = R"(
@interface I
@end
@implementation I

void nestedFunction() { }

- (void) method{ }

int anotherNestedFunction(int x) {
  return x;
}

int innerVariable = 0;

@end

int outerVariable = 0;

@implementation I(Cat)

void catF() { }

@end

void outerFunction() { }
)";
  DummyMatchVisitor Visitor;
  Visitor.DisallowMatch("/nestedFunction/", 6, 1);
  Visitor.ExpectMatch("/I/nestedFunction/", 6, 1);
  Visitor.ExpectMatch("/I/method/", 8, 1);
  Visitor.DisallowMatch("/anotherNestedFunction/", 10, 1);
  Visitor.ExpectMatch("/I/anotherNestedFunction/", 10, 1);
  Visitor.DisallowMatch("/innerVariable", 14, 1);
  Visitor.ExpectMatch("/I/innerVariable", 14, 1);
  Visitor.ExpectMatch("/outerVariable", 18, 1);
  Visitor.DisallowMatch("/catF/", 22, 1);
  Visitor.ExpectMatch("/Cat/catF/", 22, 1);
  Visitor.ExpectMatch("/outerFunction/", 26, 1);
  EXPECT_TRUE(Visitor.runOver(Source, DummyMatchVisitor::Lang_OBJC));
}

TEST(LexicallyOrderedRecursiveASTVisitor, VisitMacroDeclsInImplementation) {
  StringRef Source = R"(
@interface I
@end

void outerFunction() { }

#define MACRO_F(x) void nestedFunction##x() { }

@implementation I

MACRO_F(1)

@end

MACRO_F(2)
)";
  DummyMatchVisitor Visitor;
  Visitor.ExpectMatch("/outerFunction/", 5, 1);
  Visitor.ExpectMatch("/I/nestedFunction1/", 7, 20);
  Visitor.ExpectMatch("/nestedFunction2/", 7, 20);
  EXPECT_TRUE(Visitor.runOver(Source, DummyMatchVisitor::Lang_OBJC));
}

TEST(LexicallyOrderedRecursiveASTVisitor, VisitTemplateDecl) {
  StringRef Source = R"(
template <class T> T f();
template <class U, class = void> class Class {};
)";
  DummyMatchVisitor Visitor(/*EmitIndices=*/true);
  Visitor.ExpectMatch("/f/T@1", 2, 11);
  Visitor.ExpectMatch("/f/f/@2", 2, 20);
  Visitor.ExpectMatch("/Class/U@4", 3, 11);
  Visitor.ExpectMatch("/Class/@5", 3, 20);
  Visitor.ExpectMatch("/Class/Class/@6", 3, 34);
  EXPECT_TRUE(Visitor.runOver(Source));
}

TEST(LexicallyOrderedRecursiveASTVisitor, VisitCXXOperatorCallExpr) {
  StringRef Source = R"(
struct S {
  S &operator+(S&);
  S *operator->();
  S &operator++();
  S operator++(int);
  void operator()(int, int);
  void operator[](int);
  void f();
};
S a, b, c;

void test() {
  a = b + c;
  a->f();
  a(1, 2);
  b[0];
  ++a;
  b++;
}
)";
  DummyMatchVisitor Visitor(/*EmitDeclIndices=*/false,
                            /*EmitStmtIndices=*/true);
  // There are two overloaded operators that start at this point
  // This makes sure they are both traversed using the overridden
  // TraverseStmt, as the traversal is implemented by us for
  // CXXOperatorCallExpr.
  Visitor.ExpectMatch("overridden TraverseStmt", 14, 3, 2);
  Visitor.ExpectMatch("a@0", 14, 3);
  Visitor.ExpectMatch("operator=@1", 14, 5);
  Visitor.ExpectMatch("b@2", 14, 7);
  Visitor.ExpectMatch("operator+@3", 14, 9);
  Visitor.ExpectMatch("c@4", 14, 11);
  Visitor.ExpectMatch("operator->@6", 15, 4);
  Visitor.ExpectMatch("operator()@8", 16, 4);
  Visitor.ExpectMatch("operator[]@10", 17, 4);
  Visitor.ExpectMatch("operator++@11", 18, 3);
  Visitor.ExpectMatch("operator++@14", 19, 4);
  EXPECT_TRUE(Visitor.runOver(Source));
}

} // end anonymous namespace