llvm-project

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//===- unittests/AST/TypePrinterTest.cpp --- Type printer tests -----------===//
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//
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// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
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// See https://llvm.org/LICENSE.txt for license information.
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// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
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//
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//===----------------------------------------------------------------------===//
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//
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// This file contains tests for QualType::print() and related methods.
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//
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//===----------------------------------------------------------------------===//
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#include "ASTPrint.h"
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#include "clang/AST/ASTContext.h"
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#include "clang/ASTMatchers/ASTMatchFinder.h"
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#include "clang/Tooling/Tooling.h"
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#include "llvm/ADT/SmallString.h"
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#include "gtest/gtest.h"
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using namespace clang;
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using namespace ast_matchers;
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using namespace tooling;
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namespace {
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static void PrintType(raw_ostream &Out, const ASTContext *Context,
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                      const QualType *T,
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                      PrintingPolicyAdjuster PolicyAdjuster) {
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  assert(T && !T->isNull() && "Expected non-null Type");
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  PrintingPolicy Policy = Context->getPrintingPolicy();
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  if (PolicyAdjuster)
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    PolicyAdjuster(Policy);
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  T->print(Out, Policy);
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}
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::testing::AssertionResult
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PrintedTypeMatches(StringRef Code, const std::vector<std::string> &Args,
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                   const DeclarationMatcher &NodeMatch,
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                   StringRef ExpectedPrinted,
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                   PrintingPolicyAdjuster PolicyAdjuster) {
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  return PrintedNodeMatches<QualType>(Code, Args, NodeMatch, ExpectedPrinted,
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                                      "", PrintType, PolicyAdjuster);
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}
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} // unnamed namespace
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TEST(TypePrinter, TemplateId) {
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  std::string Code = R"cpp(
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    namespace N {
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      template <typename> struct Type {};
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      template <typename T>
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      void Foo(const Type<T> &Param);
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    }
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  )cpp";
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  auto Matcher = parmVarDecl(hasType(qualType().bind("id")));
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  ASSERT_TRUE(PrintedTypeMatches(
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      Code, {}, Matcher, "const Type<T> &",
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      [](PrintingPolicy &Policy) { Policy.FullyQualifiedName = false; }));
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  ASSERT_TRUE(PrintedTypeMatches(
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      Code, {}, Matcher, "const Type<T> &",
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      [](PrintingPolicy &Policy) { Policy.FullyQualifiedName = true; }));
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}
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TEST(TypePrinter, TemplateId2) {
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  std::string Code = R"cpp(
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      template <template <typename ...> class TemplatedType>
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      void func(TemplatedType<int> Param);
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    )cpp";
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  auto Matcher = parmVarDecl(hasType(qualType().bind("id")));
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  // Regression test ensuring we do not segfault getting the QualType as a
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  // string.
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  ASSERT_TRUE(PrintedTypeMatches(Code, {}, Matcher, "<int>",
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                                 [](PrintingPolicy &Policy) {
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                                   Policy.FullyQualifiedName = true;
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                                   Policy.PrintCanonicalTypes = true;
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                                 }));
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}
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TEST(TypePrinter, ParamsUglified) {
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  llvm::StringLiteral Code = R"cpp(
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    template <typename _Tp, template <typename> class __f>
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    const __f<_Tp&> *A = nullptr;
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  )cpp";
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  auto Clean = [](PrintingPolicy &Policy) {
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    Policy.CleanUglifiedParameters = true;
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  };
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  ASSERT_TRUE(PrintedTypeMatches(Code, {},
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                                 varDecl(hasType(qualType().bind("id"))),
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                                 "const __f<_Tp &> *", nullptr));
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  ASSERT_TRUE(PrintedTypeMatches(Code, {},
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                                 varDecl(hasType(qualType().bind("id"))),
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                                 "const f<Tp &> *", Clean));
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}
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TEST(TypePrinter, SuppressElaboration) {
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  llvm::StringLiteral Code = R"cpp(
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    namespace shared {
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    namespace a {
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    template <typename T>
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    struct S {};
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    }  // namespace a
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    namespace b {
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    struct Foo {};
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    }  // namespace b
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    using Alias = a::S<b::Foo>;
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    }  // namespace shared
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  )cpp";
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  auto Matcher = typedefNameDecl(hasName("::shared::Alias"),
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                                 hasType(qualType().bind("id")));
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  ASSERT_TRUE(PrintedTypeMatches(
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      Code, {}, Matcher, "a::S<b::Foo>",
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      [](PrintingPolicy &Policy) { Policy.FullyQualifiedName = true; }));
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  ASSERT_TRUE(PrintedTypeMatches(Code, {}, Matcher,
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                                 "shared::a::S<shared::b::Foo>",
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                                 [](PrintingPolicy &Policy) {
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                                   Policy.SuppressElaboration = true;
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                                   Policy.FullyQualifiedName = true;
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                                 }));
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}
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TEST(TypePrinter, TemplateIdWithNTTP) {
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  constexpr char Code[] = R"cpp(
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    template <int N>
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    struct Str {
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      constexpr Str(char const (&s)[N]) { __builtin_memcpy(value, s, N); }
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      char value[N];
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    };
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    template <Str> class ASCII {};
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    ASCII<"this nontype template argument is too long to print"> x;
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  )cpp";
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  auto Matcher = classTemplateSpecializationDecl(
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      hasName("ASCII"), has(cxxConstructorDecl(
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                            isMoveConstructor(),
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                            has(parmVarDecl(hasType(qualType().bind("id")))))));
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  ASSERT_TRUE(PrintedTypeMatches(
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      Code, {"-std=c++20"}, Matcher,
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      R"(ASCII<Str<52>{"this nontype template argument is [...]"}> &&)",
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      [](PrintingPolicy &Policy) {
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        Policy.EntireContentsOfLargeArray = false;
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      }));
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  ASSERT_TRUE(PrintedTypeMatches(
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      Code, {"-std=c++20"}, Matcher,
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      R"(ASCII<Str<52>{"this nontype template argument is too long to print"}> &&)",
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      [](PrintingPolicy &Policy) {
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        Policy.EntireContentsOfLargeArray = true;
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      }));
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}
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TEST(TypePrinter, TemplateArgumentsSubstitution) {
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  constexpr char Code[] = R"cpp(
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       template <typename Y> class X {};
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       typedef X<int> A;
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       int foo() {
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          return sizeof(A);
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       }
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  )cpp";
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  auto Matcher = typedefNameDecl(hasName("A"), hasType(qualType().bind("id")));
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  ASSERT_TRUE(PrintedTypeMatches(Code, {}, Matcher, "X<int>",
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                                 [](PrintingPolicy &Policy) {
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                                   Policy.SuppressTagKeyword = false;
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                                   Policy.SuppressScope = true;
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                                 }));
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}
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TEST(TypePrinter, TemplateArgumentsSubstitution_Expressions) {
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  /// Tests clang::isSubstitutedDefaultArgument on TemplateArguments
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  /// that are of kind TemplateArgument::Expression
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  constexpr char Code[] = R"cpp(
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    constexpr bool func() { return true; }
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    template <typename T1 = int,
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              int      T2 = 42,
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              T1       T3 = 43,
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              int      T4 = sizeof(T1),
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              bool     T5 = func()
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              >
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    struct Foo {
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    };
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    Foo<int, 40 + 2> X;
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  )cpp";
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  auto AST = tooling::buildASTFromCodeWithArgs(Code, /*Args=*/{"-std=c++20"});
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  ASTContext &Ctx = AST->getASTContext();
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  auto const *CTD = selectFirst<ClassTemplateDecl>(
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      "id", match(classTemplateDecl(hasName("Foo")).bind("id"), Ctx));
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  ASSERT_NE(CTD, nullptr);
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  auto const *CTSD = *CTD->specializations().begin();
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  ASSERT_NE(CTSD, nullptr);
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  auto const *Params = CTD->getTemplateParameters();
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  ASSERT_NE(Params, nullptr);
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  auto const &ArgList = CTSD->getTemplateArgs();
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  auto createBinOpExpr = [&](uint32_t LHS, uint32_t RHS,
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                             uint32_t Result) -> ConstantExpr * {
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    const int numBits = 32;
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    clang::APValue ResultVal{llvm::APSInt(llvm::APInt(numBits, Result))};
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    auto *LHSInt = IntegerLiteral::Create(Ctx, llvm::APInt(numBits, LHS),
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                                          Ctx.UnsignedIntTy, {});
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    auto *RHSInt = IntegerLiteral::Create(Ctx, llvm::APInt(numBits, RHS),
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                                          Ctx.UnsignedIntTy, {});
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    auto *BinOp = BinaryOperator::Create(
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        Ctx, LHSInt, RHSInt, BinaryOperatorKind::BO_Add, Ctx.UnsignedIntTy,
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        ExprValueKind::VK_PRValue, ExprObjectKind::OK_Ordinary, {}, {});
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    return ConstantExpr::Create(Ctx, dyn_cast<Expr>(BinOp), ResultVal);
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  };
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  {
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    // Arg is an integral '42'
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    auto const &Arg = ArgList.get(1);
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    ASSERT_EQ(Arg.getKind(), TemplateArgument::Integral);
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    // Param has default expr which evaluates to '42'
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    auto const *Param = Params->getParam(1);
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    EXPECT_TRUE(clang::isSubstitutedDefaultArgument(
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        Ctx, Arg, Param, ArgList.asArray(), Params->getDepth()));
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  }
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  {
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    // Arg is an integral '41'
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    llvm::APInt Int(32, 41);
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    TemplateArgument Arg(Ctx, llvm::APSInt(Int), Ctx.UnsignedIntTy);
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    // Param has default expr which evaluates to '42'
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    auto const *Param = Params->getParam(1);
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    EXPECT_FALSE(clang::isSubstitutedDefaultArgument(
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        Ctx, Arg, Param, ArgList.asArray(), Params->getDepth()));
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  }
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  {
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    // Arg is an integral '4'
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    llvm::APInt Int(32, 4);
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    TemplateArgument Arg(Ctx, llvm::APSInt(Int), Ctx.UnsignedIntTy);
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    // Param has is value-dependent expression (i.e., sizeof(T))
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    auto const *Param = Params->getParam(3);
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    EXPECT_FALSE(clang::isSubstitutedDefaultArgument(
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        Ctx, Arg, Param, ArgList.asArray(), Params->getDepth()));
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  }
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  {
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    const int LHS = 40;
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    const int RHS = 2;
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    const int Result = 42;
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    auto *ConstExpr = createBinOpExpr(LHS, RHS, Result);
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    // Arg is instantiated with '40 + 2'
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    TemplateArgument Arg(ConstExpr);
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    // Param has default expr of '42'
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    auto const *Param = Params->getParam(1);
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    EXPECT_TRUE(clang::isSubstitutedDefaultArgument(
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        Ctx, Arg, Param, ArgList.asArray(), Params->getDepth()));
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  }
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  {
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    const int LHS = 40;
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    const int RHS = 1;
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    const int Result = 41;
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    auto *ConstExpr = createBinOpExpr(LHS, RHS, Result);
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    // Arg is instantiated with '40 + 1'
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    TemplateArgument Arg(ConstExpr);
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    // Param has default expr of '42'
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    auto const *Param = Params->getParam(1);
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    EXPECT_FALSE(clang::isSubstitutedDefaultArgument(
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        Ctx, Arg, Param, ArgList.asArray(), Params->getDepth()));
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  }
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  {
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    const int LHS = 4;
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    const int RHS = 0;
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    const int Result = 4;
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    auto *ConstExpr = createBinOpExpr(LHS, RHS, Result);
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    // Arg is instantiated with '4 + 0'
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    TemplateArgument Arg(ConstExpr);
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    // Param has is value-dependent expression (i.e., sizeof(T))
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    auto const *Param = Params->getParam(3);
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    EXPECT_FALSE(clang::isSubstitutedDefaultArgument(
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        Ctx, Arg, Param, ArgList.asArray(), Params->getDepth()));
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  }
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}
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