// Part of the Crubit project, under the Apache License v2.0 with LLVM
// Exceptions. See /LICENSE for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception

// Tests for nullability annotations in template arguments.

#include "nullability/test/check_diagnostics.h"
#include "third_party/llvm/llvm-project/third-party/unittest/googletest/include/gtest/gtest.h"

namespace clang {
namespace tidy {
namespace nullability {
namespace {

// TODO: Fix false negatives.
TEST(PointerNullabilityTest, ClassTemplateInstantiation) {
  // Class template specialization with one argument initialised as _Nullable.
  // We test types that contain both nullability that is substituted into the
  // template argument and nullability that is spelt inside the template. That
  // is, we should be able to accurately store nullabilities from different
  // sources in a single nullability vector.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0>
    struct Struct1Arg {
      T0 arg0;
      T0 *unknownTPtr;
      T0 *_Nullable nullableTPtr;
      T0 *_Nonnull nonnullTPtr;

      T0 getT();
      T0 *getUnknownTPtr();
      T0 *_Nullable getNullableTPtr();
      T0 *_Nonnull getNonnullTPtr();
    };
    void target(Struct1Arg<int *_Nullable> p) {
      *p.arg0;  // [[unsafe]]
      *p.unknownTPtr;
      *p.nullableTPtr;  // [[unsafe]]
      *p.nonnullTPtr;
      **p.unknownTPtr;   // [[unsafe]]
      **p.nullableTPtr;  // [[unsafe]]
      **p.nonnullTPtr;   // [[unsafe]]

      *p.getT();  // [[unsafe]]
      *p.getUnknownTPtr();
      *p.getNullableTPtr();  // [[unsafe]]
      *p.getNonnullTPtr();
      **p.getUnknownTPtr();   // [[unsafe]]
      **p.getNullableTPtr();  // [[unsafe]]
      **p.getNonnullTPtr();   // [[unsafe]]
    }
  )cc"));

  // Class template specialization with one argument initialised as _Nonnull.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0>
    struct Struct1Arg {
      T0 arg0;
      T0 *unknownTPtr;
      T0 *_Nullable nullableTPtr;
      T0 *_Nonnull nonnullTPtr;

      T0 getT();
      T0 *getUnknownTPtr();
      T0 *_Nullable getNullableTPtr();
      T0 *_Nonnull getNonnullTPtr();
    };

    void target(Struct1Arg<int *_Nonnull> p) {
      *p.getT();
      *p.getUnknownTPtr();
      *p.getNullableTPtr();  // [[unsafe]]
      *p.getNonnullTPtr();
      **p.getUnknownTPtr();
      **p.getNullableTPtr();  // [[unsafe]]
      **p.getNonnullTPtr();

      *p.arg0;
      *p.unknownTPtr;
      *p.nullableTPtr;  // [[unsafe]]
      *p.nonnullTPtr;
      **p.unknownTPtr;
      **p.nullableTPtr;  // [[unsafe]]
      **p.nonnullTPtr;
    }
  )cc"));

  // Class template specialization with one argument initialised without
  // nullability annotation.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0>
    struct Struct1Arg {
      T0 arg0;
      T0 *unknownTPtr;
      T0 *_Nullable nullableTPtr;
      T0 *_Nonnull nonnullTPtr;
      T0 getT();

      T0 *getUnknownTPtr();
      T0 *_Nullable getNullableTPtr();
      T0 *_Nonnull getNonnullTPtr();
    };

    void target(Struct1Arg<int *> p) {
      *p.getT();
      *p.getUnknownTPtr();
      *p.getNullableTPtr();  // [[unsafe]]
      *p.getNonnullTPtr();
      **p.getUnknownTPtr();
      **p.getNullableTPtr();  // [[unasfe]]
      **p.getNonnullTPtr();

      *p.arg0;
      *p.unknownTPtr;
      *p.nullableTPtr;  // [[unsafe]]
      *p.nonnullTPtr;
      **p.unknownTPtr;
      **p.nullableTPtr;  // [[unsafe]]
      **p.nonnullTPtr;
    }
  )cc"));

  // Class template specialization with two arguments, whose second argument is
  // initialized as nullable.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1>
    struct Struct2Arg {
      T0 arg0;
      T0 *unknownT0Ptr;
      T0 *_Nullable nullableT0Ptr;
      T0 *_Nonnull nonnullT0Ptr;

      T1 arg1;
      T1 *unknownT1Ptr;
      T1 *_Nullable nullableT1Ptr;
      T1 *_Nonnull nonnullT1Ptr;

      T0 getT0();
      T0 *getUnknownT0Ptr();
      T0 *_Nullable getNullableT0Ptr();
      T0 *_Nonnull getNonnullT0Ptr();

      T1 getT1();
      T1 *getUnknownT1Ptr();
      T1 *_Nullable getNullableT1Ptr();
      T1 *_Nonnull getNonnullT1Ptr();
    };

    void target(Struct2Arg<int *_Nonnull, double *_Nullable> p) {
      *p.arg0;
      *p.arg1;  // [[unsafe]]

      *p.unknownT0Ptr;
      *p.nullableT0Ptr;  // [[unsafe]]
      *p.nonnullT0Ptr;

      *p.unknownT1Ptr;
      *p.nullableT1Ptr;  // [[unsafe]]
      *p.nonnullT1Ptr;

      *p.getUnknownT0Ptr();
      *p.getNullableT0Ptr();  // [[unsafe]]
      *p.getNonnullT0Ptr();

      *p.getUnknownT1Ptr();
      *p.getNullableT1Ptr();  // [[unsafe]]
      *p.getNonnullT1Ptr();
    }
  )cc"));

  // Class template specialization with 5 arguments with interleaved
  // nullable/nonnull/unknown.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1, typename T2, typename T3, typename T4>
    struct Struct5Arg {
      T0 arg0;
      T1 arg1;
      T2 arg2;
      T3 arg3;
      T4 arg4;

      T0 getT0();
      T1 getT1();
      T2 getT2();
      T3 getT3();
      T4 getT4();
    };
    void target(Struct5Arg<int* _Nullable, double* _Nonnull, float*,
                           double* _Nullable, int* _Nonnull>
                    p) {
      *p.arg0;  // [[unsafe]]
      *p.arg1;
      *p.arg2;
      *p.arg3;  // [[unsafe]]
      *p.arg4;

      *p.getT0();  // [[unsafe]]
      *p.getT1();
      *p.getT2();
      *p.getT3();  // [[unsafe]]
      *p.getT4();
    }
  )cc"));

  // Class template specialization with 5 arguments with interleaved
  // nullable/nonnull/unknown/const.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1, typename T2, typename T3, typename T4>
    struct Struct5Arg {
      T0 arg0;
      T1 arg1;
      T2 arg2;
      T3 arg3;
      T4 arg4;

      T0 getT0();
      T1 getT1();
      T2 getT2();
      T3 getT3();
      T4 getT4();
    };
    void target(Struct5Arg<int* const _Nullable, double const* const _Nonnull,
                           float*, double const* const _Nullable, int* _Nonnull>
                    p) {
      *p.arg0;  // [[unsafe]]
      *p.arg1;
      *p.arg2;
      *p.arg3;  // [[unsafe]]
      *p.arg4;

      *p.getT0();  // [[unsafe]]
      *p.getT1();
      *p.getT2();
      *p.getT3();  // [[unsafe]]
      *p.getT4();
    }
  )cc"));

  // Class template specialization with interleaved int and type template
  // parameters.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <int I0, typename T1, int I2, typename T3, int I4, typename T5>
    struct Struct6ArgWithInt {
      T1 arg1;
      T3 arg3;
      T5 arg5;

      T1 getT1();
      T3 getT3();
      T5 getT5();
    };
    void target(
        Struct6ArgWithInt<0, int *_Nullable, 1, int *_Nullable, 2, int *> &x) {
      *x.arg1;  // [[unsafe]]
      *x.arg3;  // [[unsafe]]
      *x.arg5;

      *x.getT1();  // [[unsafe]]
      *x.getT3();  // [[unsafe]]
      *x.getT5();
    }
  )cc"));
}

// TODO: Fix false positives and false negatives.
TEST(PointerNullabilityTest,
     ClassTemplateInstantiationWithStructsAsParameters) {
  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct Struct3IntPtrs {
      int* unknown;
      int* _Nullable nullable;
      int* _Nonnull nonnull;

      int* getUnknown();
      int* _Nullable getNullable();
      int* _Nonnull getNonnull();
    };

    template <typename T0>
    struct Struct1Arg {
      T0 arg0;
      T0 getT0();
    };

    void target(Struct1Arg<Struct3IntPtrs> p) {
      *p.arg0.unknown;
      *p.arg0.nullable;  // [[unsafe]]
      *p.arg0.nonnull;

      *p.arg0.getUnknown();
      *p.arg0.getNullable();  // [[unsafe]]
      *p.arg0.getNonnull();

      *p.getT0().unknown;   // [[unsafe]] TODO: fix false positive.
      *p.getT0().nullable;  // [[unsafe]]
      *p.getT0().nonnull;   // [[unsafe]] TODO: fix false positive.

      *p.getT0().getUnknown();
      *p.getT0().getNullable();  // [[unsafe]]
      *p.getT0().getNonnull();
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct Struct1UnknownArg {
      char* unknownChar;

      char* getUnknownChar();
    };

    struct Struct1NullableArg {
      char* _Nullable nullableChar;

      char* _Nullable getNullableChar();
    };

    struct Struct1NonnullArg {
      char* _Nonnull nonnullChar;

      char* _Nonnull getNonnullChar();
    };

    struct StructLotsOfArgs {
      int num;
      long long* unknownLongLong;
      double* _Nullable nullableDouble;
      float* _Nonnull nonnullFloat;
      short* unknownShort;
      unsigned int* _Nullable nullableUInt;
      bool* _Nullable nullableBool;

      long long* getUnknownLongLong();
      double* _Nullable getNullableDouble();
      float* _Nonnull getNonnullFloat();
      short* getUnknownShort();
      unsigned int* _Nullable getNullableUInt();
      bool* _Nullable getNullableBool();
    };

    template <typename T0, typename T1, typename T2, typename T3>
    struct Struct4Arg {
      T0 arg0;
      T1 arg1;
      T2 arg2;
      T3 arg3;

      T0 getT0();
      T1 getT1();
      T2 getT2();
      T3 getT3();
    };

    void target(Struct4Arg<Struct1UnknownArg, Struct1NullableArg,
                           Struct1NonnullArg, StructLotsOfArgs>
                    p) {
      *p.arg0.unknownChar;
      *p.arg1.nullableChar;  // [[unsafe]]
      *p.arg2.nonnullChar;
      *p.arg3.unknownLongLong;
      *p.arg3.nullableDouble;  // [[unsafe]]
      *p.arg3.nonnullFloat;
      *p.arg3.unknownShort;
      *p.arg3.nullableUInt;  // [[unsafe]]
      *p.arg3.nullableBool;  // [[unsafe]]

      *p.arg0.getUnknownChar();
      *p.arg1.getNullableChar();  // [[unsafe]]
      *p.arg2.getNonnullChar();
      *p.arg3.getUnknownLongLong();
      *p.arg3.getNullableDouble();  // [[unsafe]]
      *p.arg3.getNonnullFloat();
      *p.arg3.getUnknownShort();
      *p.arg3.getNullableUInt();  // [[unsafe]]
      *p.arg3.getNullableBool();  // [[unsafe]]

      *p.getT0().unknownChar;      // [[unsafe]] TODO: fix false positive.
      *p.getT1().nullableChar;     // [[unsafe]]
      *p.getT2().nonnullChar;      // [[unsafe]] TODO: fix false positive.
      *p.getT3().unknownLongLong;  // [[unsafe]] TODO: fix false positive.
      *p.getT3().nullableDouble;   // [[unsafe]]
      *p.getT3().nonnullFloat;     // [[unsafe]] TODO: fix false positive.
      *p.getT3().unknownShort;     // [[unsafe]] TODO: fix false positive.
      *p.getT3().nullableUInt;     // [[unsafe]]
      *p.getT3().nullableBool;     // [[unsafe]]

      *p.getT0().getUnknownChar();
      *p.getT1().getNullableChar();  // [[unsafe]]
      *p.getT2().getNonnullChar();
      *p.getT3().getUnknownLongLong();
      *p.getT3().getNullableDouble();  // [[unsafe]]
      *p.getT3().getNonnullFloat();
      *p.getT3().getUnknownShort();
      *p.getT3().getNullableUInt();  // [[unsafe]]
      *p.getT3().getNullableBool();  // [[unsafe]]
    }
  )cc"));

  // With const arguments and int template parameter.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct Struct1UnknownArg {
      char* const constUnknownChar;
      char const* unknownConstChar;
      char const* const constUnknownConstChar;

      char* const getConstUnknownChar();
      char const* getUnknownConstChar();
      char const* const getConstUnknownConstChar();
    };

    struct Struct1NullableArg {
      char* const _Nullable constNullableChar;
      char const* _Nullable nullableConstChar;
      char const* const _Nullable constNullableConstChar;

      char* const _Nullable getConstNullableChar();
      char const* _Nullable getNullableConstChar();
      char* const* _Nullable getConstNullableConstChar();
    };

    struct Struct1NonnullArg {
      char* const _Nonnull constNonnullChar;
      char const* _Nonnull nonnullConstChar;
      char const* const _Nonnull constNonnullConstChar;

      char* const _Nonnull getConstNonnullChar();
      char const* _Nonnull getNonnullConstChar();
      char const* const _Nonnull getConstNonnullConstChar();
    };

    template <int I0, typename T1, typename T2, typename T3>
    struct Struct4Arg {
      T1 arg1;
      T2 arg2;
      T3 arg3;

      T1 getT1();
      T2 getT2();
      T3 getT3();
    };

    void target(
        Struct4Arg<4, Struct1UnknownArg, Struct1NullableArg, Struct1NonnullArg>
            p) {
      *p.arg1.constUnknownChar;
      *p.arg1.unknownConstChar;
      *p.arg1.constUnknownConstChar;
      *p.arg2.constNullableChar;       // [[unsafe]]
      *p.arg2.nullableConstChar;       // [[unsafe]]
      *p.arg2.constNullableConstChar;  // [[unsafe]]
      *p.arg3.constNonnullChar;
      *p.arg3.nonnullConstChar;
      *p.arg3.constNonnullConstChar;

      *p.arg1.getConstUnknownChar();
      *p.arg1.getUnknownConstChar();
      *p.arg1.getConstUnknownConstChar();
      *p.arg2.getConstNullableChar();       // [[unsafe]]
      *p.arg2.getNullableConstChar();       // [[unsafe]]
      *p.arg2.getConstNullableConstChar();  // [[unsafe]]
      *p.arg3.getConstNonnullChar();
      *p.arg3.getNonnullConstChar();
      *p.arg3.getConstNonnullConstChar();

      *p.getT1().constUnknownChar;       // [[unsafe]] TODO: fix false positive.
      *p.getT1().unknownConstChar;       // [[unsafe]] TODO: fix false positive.
      *p.getT1().constUnknownConstChar;  // [[unsafe]] TODO: fix false positive.
      *p.getT2().constNullableChar;      // [[unsafe]]
      *p.getT2().nullableConstChar;      // [[unsafe]]
      *p.getT2().constNullableConstChar;  // [[unsafe]]
      *p.getT3().constNonnullChar;       // [[unsafe]] TODO: fix false positive.
      *p.getT3().nonnullConstChar;       // [[unsafe]] TODO: fix false positive.
      *p.getT3().constNonnullConstChar;  // [[unsafe]] TODO: fix false positive.

      *p.getT1().getConstUnknownChar();
      *p.getT1().getUnknownConstChar();
      *p.getT1().getConstUnknownConstChar();
      *p.getT2().getConstNullableChar();       // [[unsafe]]
      *p.getT2().getNullableConstChar();       // [[unsafe]]
      *p.getT2().getConstNullableConstChar();  // [[unsafe]]
      *p.getT3().getConstNonnullChar();
      *p.getT3().getNonnullConstChar();
      *p.getT3().getConstNonnullConstChar();
    }
  )cc"));
}

// TODO: Fix false negatives.
TEST(PointerNullabilityTest, MemberFunctionTemplateOfConcreteStruct) {
  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct S {
      template <typename T0>
      T0 getT0();
    };

    void target(S p) {
      *p.getT0<int *>();
      *p.getT0<int *_Nonnull>();
      *p.getT0<int *_Nullable>();  // TODO: fix false negative.

      *p.getT0<int const *>();
      *p.getT0<int *const>();
      *p.getT0<int const *const>();
      *p.getT0<int const *_Nonnull>();
      *p.getT0<int *const _Nonnull>();
      *p.getT0<int const *const _Nonnull>();
      *p.getT0<int const *_Nullable>();        // TODO: fix false negative.
      *p.getT0<int *const _Nullable>();        // TODO: fix false negative.
      *p.getT0<int const *const _Nullable>();  // TODO: fix false negative.
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct S {
      template <int I0, typename T1, int I2>
      T1 getT1();
    };

    void target(S p) {
      *p.getT1<0, int *, 1>();
      *p.getT1<2147483647, int *_Nonnull, -2147483647>();
      *p.getT1<4, int *_Nullable, 4>();  // TODO: fix false negative.
    }
  )cc"));
}

TEST(PointerNullabilityTest, MemberFunctionTemplateOfTemplateStruct) {
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0>
    struct S {
      template <typename TN1>
      TN1 getTN1();
    };

    void target(S<int> p) {
      *p.getTN1<int *>();
      *p.getTN1<int *_Nonnull>();
      *p.getTN1<int *_Nullable>();  // TODO: fix false negative.

      *p.getTN1<int const *>();
      *p.getTN1<int *const>();
      *p.getTN1<int const *const>();
      *p.getTN1<int const *_Nonnull>();
      *p.getTN1<int *const _Nonnull>();
      *p.getTN1<int const *const _Nonnull>();
      *p.getTN1<int const *_Nullable>();        // TODO: fix false negative.
      *p.getTN1<int *const _Nullable>();        // TODO: fix false negative.
      *p.getTN1<int const *const _Nullable>();  // TODO: fix false negative.
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0>
    struct S {
      template <int IN1, typename TN2, int IN3>
      TN2 getTN2();
    };

    void target(S<int> p) {
      *p.getTN2<0, int *, 1>();
      *p.getTN2<2147483647, int *_Nonnull, -2147483647>();
      *p.getTN2<4, int *_Nullable, 4>();  // TODO: fix false negative.
    }
  )cc"));
}

// TODO: Fix false positives.
TEST(PointerNullabilityTest,
     ClassTemplateInstantiationWithTemplateStructsAsParameters) {
  // Class template with another class template as parameter
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1>
    struct Struct2Arg {
      T0 arg0;
      T1 arg1;
    };

    template <typename TN0, typename TN1>
    struct Struct2ArgNested {
      Struct2Arg<TN1, Struct2Arg<TN0, TN1>>* arg0;
      Struct2Arg<TN1, Struct2Arg<TN0, TN1>>* _Nullable arg1;
    };

    void target(Struct2ArgNested<int* _Nonnull, double* _Nullable> p) {
      *p.arg0;
      *p.arg1;  // [[unsafe]]

      *p.arg0->arg0;
      *p.arg0->arg1.arg0;
      *p.arg0->arg1.arg1;
    }
  )cc"));

  // Class template with itself as parameter
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1>
    struct Struct2Arg {
      T0 arg0;
      T1 arg1;
    };

    void target(Struct2Arg<Struct2Arg<int*, int* _Nullable>, int* _Nonnull> p) {
      *p.arg0.arg0;
      *p.arg0.arg1;  // [[unsafe]]
      *p.arg1;
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1, typename T2, typename T3, typename T4>
    struct Struct5Arg {
      T0 arg0;
      T1 arg1;
      T2 arg2;
      T3 arg3;
      T4 arg4;
    };

    void
    target(Struct5Arg<
           Struct5Arg<
               Struct5Arg<Struct5Arg<int* _Nullable, int* _Nonnull,
                                     float* _Nullable, int*, double* _Nullable>,
                          int, int, int, int* _Nullable>,
               int, int* _Nullable, int, int>,
           int, int* _Nullable, int* _Nonnull, int>
               p) {
      *p.arg0.arg0.arg0.arg0;  // [[unsafe]]
      *p.arg0.arg0.arg0.arg1;  // [[unsafe]] TODO: fix false positive.
      *p.arg0.arg0.arg0.arg2;  // [[unsafe]]
      *p.arg0.arg0.arg0.arg3;  // [[unsafe]] TODO: fix false positive.
      *p.arg0.arg0.arg0.arg4;  // [[unsafe]]
      *p.arg0.arg0.arg4;       // [[unsafe]]
      *p.arg0.arg2;            // [[unsafe]]
      *p.arg2;                 // [[unsafe]]
      *p.arg3;
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <int I0, typename T1, typename T2, typename T3, int I4,
              typename T5, typename T6>
    struct Struct7ArgWithInt {
      T1 arg1;
      T2 arg2;
      T3 arg3;
      T5 arg5;
      T6 arg6;
    };

    void target(Struct7ArgWithInt<
                0,
                Struct7ArgWithInt<
                    2147483647,
                    Struct7ArgWithInt<
                        0,
                        Struct7ArgWithInt<-2147483647, int* _Nullable,
                                          int* _Nonnull, float* _Nullable, 0,
                                          int*, double* _Nullable>,
                        int, int, 1, int, int* _Nullable>,
                    int, int* _Nullable, 2147483647, int, int>,
                int, int* _Nullable, 2, int* _Nonnull, int>
                    p) {
      *p.arg1.arg1.arg1.arg1;  // [[unsafe]]
      *p.arg1.arg1.arg1.arg2;  // [[unsafe]] TODO: fix false positive.
      *p.arg1.arg1.arg1.arg3;  // [[unsafe]]
      *p.arg1.arg1.arg1.arg5;  // [[unsafe]] TODO: fix false positive.
      *p.arg1.arg1.arg1.arg6;  // [[unsafe]]
      *p.arg1.arg1.arg6;       // [[unsafe]]
      *p.arg1.arg3;            // [[unsafe]]
      *p.arg3;                 // [[unsafe]]
      *p.arg5;
    }
  )cc"));
}

TEST(PointerNullabilityTest,
     ClassTemplateInstantiationWithPointersToStructsAsParameters) {
  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct Struct3IntPtrs {
      int* unknown;
      int* _Nullable nullable;
      int* _Nonnull nonnull;

      int* getUnknown();
      int* _Nullable getNullable();
      int* _Nonnull getNonnull();
    };

    template <typename T0>
    struct Struct1Arg {
      T0 arg0;

      T0 getT0();
    };

    void target(Struct1Arg<Struct3IntPtrs*> p) {
      *p.arg0->unknown;
      *p.arg0->nullable;  // [[unsafe]]
      *p.arg0->nonnull;

      *p.arg0->getUnknown();
      *p.arg0->getNullable();  // [[unsafe]]
      *p.arg0->getNonnull();

      *p.getT0()->unknown;
      *p.getT0()->nullable;  // [[unsafe]]
      *p.getT0()->nonnull;

      *p.getT0()->getUnknown();
      *p.getT0()->getNullable();  // [[unsafe]]
      *p.getT0()->getNonnull();
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct Struct3IntPtrs {
      int* unknown;
      int* _Nullable nullable;
      int* _Nonnull nonnull;

      int* getUnknown();
      int* _Nullable getNullable();
      int* _Nonnull getNonnull();
    };

    template <typename T0>
    struct Struct1Arg {
      T0 arg0;

      T0 getT0();
    };

    void target(Struct1Arg<Struct3IntPtrs* _Nullable> p) {
      *p.arg0->unknown;   // [[unsafe]]
      *p.arg0->nullable;  // [[unsafe]]
      *p.arg0->nonnull;   // [[unsafe]]

      *p.arg0->getUnknown();   // [[unsafe]]
      *p.arg0->getNullable();  // [[unsafe]]
      *p.arg0->getNonnull();   // [[unsafe]]

      *p.getT0()->unknown;   // [[unsafe]]
      *p.getT0()->nullable;  // [[unsafe]]
      *p.getT0()->nonnull;   // [[unsafe]]

      *p.getT0()->getUnknown();   // [[unsafe]]
      *p.getT0()->getNullable();  // [[unsafe]]
      *p.getT0()->getNonnull();   // [[unsafe]]
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct Struct3IntPtrs {
      int* unknown;
      int* _Nullable nullable;
      int* _Nonnull nonnull;

      int* getUnknown();
      int* _Nullable getNullable();
      int* _Nonnull getNonnull();
    };

    template <typename T0>
    struct Struct1Arg {
      T0 arg0;

      T0 getT0();
    };

    void target(Struct1Arg<Struct3IntPtrs* _Nonnull> p) {
      *p.arg0->unknown;
      *p.arg0->nullable;  // [[unsafe]]
      *p.arg0->nonnull;

      *p.arg0->getUnknown();
      *p.arg0->getNullable();  // [[unsafe]]
      *p.arg0->getNonnull();

      *p.getT0()->unknown;
      *p.getT0()->nullable;  // [[unsafe]]
      *p.getT0()->nonnull;

      *p.getT0()->getUnknown();
      *p.getT0()->getNullable();  // [[unsafe]]
      *p.getT0()->getNonnull();
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct Struct3IntPtrs {
      int* unknown;
      int* _Nullable nullable;
      int* _Nonnull nonnull;

      int* getUnknown();
      int* _Nullable getNullable();
      int* _Nonnull getNonnull();
    };

    template <int I0, typename T1>
    struct Struct2Arg {
      T1 arg1;

      T1 getT1();
    };

    void target(Struct2Arg<0, Struct3IntPtrs*> p) {
      *p.arg1->unknown;
      *p.arg1->nullable;  // [[unsafe]]
      *p.arg1->nonnull;

      *p.arg1->getUnknown();
      *p.arg1->getNullable();  // [[unsafe]]
      *p.arg1->getNonnull();

      *p.getT1()->unknown;
      *p.getT1()->nullable;  // [[unsafe]]
      *p.getT1()->nonnull;
      *p.getT1()->getUnknown();
      *p.getT1()->getNullable();  // [[unsafe]]
      *p.getT1()->getNonnull();
    }
  )cc"));
}

TEST(PointerNullabilityTest,
     ClassTemplateInstantiationWithPointersToTemplateStructsAsParameters) {
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1>
    struct Struct2Arg {
      T0 arg0;
      T1 arg1;

      T0 getT0();
      T1 getT1();
    };

    void target(Struct2Arg<Struct2Arg<int *, int *_Nullable> *_Nullable,
                           Struct2Arg<int, int *> *_Nonnull>
                    p) {
      *p.arg0;        // [[unsafe]]
      *p.arg0->arg0;  // [[unsafe]]
      *p.arg0->arg1;  // [[unsafe]]
      *p.arg1;
      *p.arg1->arg1;

      *p.arg0->getT0();  // [[unsafe]]
      *p.arg0->getT1();  // [[unsafe]]
      *p.arg1->getT1();

      *p.getT0();        // [[unsafe]]
      *p.getT0()->arg0;  // [[unsafe]]
      *p.getT0()->arg1;  // [[unsafe]]
      *p.getT1();
      *p.getT1()->arg1;

      *p.getT0()->getT0();  // [[unsafe]]
      *p.getT0()->getT1();  // [[unsafe]]
      *p.getT1()->getT1();
    }
  )cc"));

  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1>
    struct StructNonnullUnknown {
      T0 nonnull;
      T1 unknown;

      T0 getNonnull();
      T1 getUnknown();
    };

    template <typename T0, typename T1>
    struct StructNonnullNullable {
      T0 nonnull;
      T1 nullable;

      T0 getNonnull();
      T1 getNullable();
    };

    template <typename T0, typename T1>
    struct StructNullableNonnull {
      T0 nullable;
      T1 nonnull;

      T0 getNullable();
      T1 getNonnull();
    };

    template <typename T0, typename T1>
    struct StructNullableNullable {
      T0 nullable0;
      T1 nullable1;

      T0 getNullable0();
      T1 getNullable1();
    };

    template <typename T0, typename T1>
    struct StructNullableUnknown {
      T0 nullable;
      T1 unknown;

      T0 getNullable();
      T1 getUnknown();
    };

    template <typename T0, typename T1>
    struct StructUnknownNullable {
      T0 unknown;
      T1 nullable;

      T0 getUnknown();
      T1 getNullable();
    };

    void
    target(StructNonnullUnknown<
           StructNonnullNullable<
               StructNullableNullable<int* _Nullable, int* _Nullable>* _Nonnull,
               StructUnknownNullable<int*,
                                     int* _Nullable>* _Nullable>* _Nonnull,
           StructUnknownNullable<
               StructUnknownNullable<int*, int* _Nullable>*,
               StructNullableNonnull<int* _Nullable,
                                     int* _Nonnull>* _Nullable>*>
               p) {
      *p.nonnull;
      *p.nonnull->nonnull;
      *p.nonnull->nonnull->nullable0;  // TODO: fix false negative.
      *p.nonnull->nonnull->nullable1;  // TODO: fix false negative.
      *p.nonnull->nullable;            // TODO: fix false negative.
      *p.nonnull->nullable->unknown;   // TODO: fix false negative.
      *p.nonnull->nullable->nullable;  // TODO: fix false negative.
      *p.unknown->unknown;
      *p.unknown->unknown->unknown;
      *p.unknown->unknown->nullable;  // TODO: fix false negative.
      *p.unknown;
      *p.unknown->nullable;            // TODO: fix false negative.
      *p.unknown->nullable->nullable;  // TODO: fix false negative.
      *p.unknown->nullable->nonnull;   // TODO: fix false negative.

      *p.nonnull->getNonnull();
      *p.nonnull->getNonnull()->nullable0;  // TODO: fix false negative.
      *p.nonnull->getNonnull()->nullable1;  // TODO: fix false negative.
      *p.nonnull->getNullable();
      *p.nonnull->getNullable()->unknown;   // TODO: fix false negative.
      *p.nonnull->getNullable()->nullable;  // TODO: fix false negative.
      *p.unknown->getUnknown();
      *p.unknown->getUnknown()->unknown;
      *p.unknown->getUnknown()->nullable;   // TODO: fix false negative.
      *p.unknown->getNullable();            // TODO: fix false negative.
      *p.unknown->getNullable()->nullable;  // TODO: fix false negative.
      *p.unknown->getNullable()->nonnull;   // TODO: fix false negative.

      *p.nonnull->getNonnull()->getNullable0();  // TODO: fix false negative.
      *p.nonnull->getNonnull()->getNullable1();  // TODO: fix false negative.
      *p.nonnull->getNullable()->getUnknown();   // TODO: fix false negative.
      *p.nonnull->getNullable()->getNullable();  // TODO: fix false negative.
      *p.unknown->getUnknown()->getUnknown();
      *p.unknown->getUnknown()->getNullable();   // TODO: fix false negative.
      *p.unknown->getNullable()->getNullable();  // TODO: fix false negative.
      *p.unknown->getNullable()->getNonnull();   // TODO: fix false negative.

      *p.nonnull->nonnull->getNullable0();  // TODO: fix false negative.
      *p.nonnull->nonnull->getNullable1();  // TODO: fix false negative.
      *p.nonnull->nullable->getUnknown();   // TODO: fix false negative.
      *p.nonnull->nullable->getNullable();  // TODO: fix false negative.
      *p.unknown->unknown->getUnknown();
      *p.unknown->unknown->getNullable();   // TODO: fix false negative.
      *p.unknown->nullable->getNullable();  // TODO: fix false negative.
      *p.unknown->nullable->getNonnull();   // TODO: fix false negative.

      *p.getNonnull();
      *p.getNonnull()->nonnull;
      *p.getNonnull()->nonnull->nullable0;  // TODO: fix false negative.
      *p.getNonnull()->nonnull->nullable1;  // TODO: fix false negative.
      *p.getNonnull()->nullable;            // TODO: fix false negative.
      *p.getNonnull()->nullable->unknown;   // TODO: fix false negative.
      *p.getNonnull()->nullable->nullable;  // TODO: fix false negative.
      *p.getUnknown()->unknown;
      *p.getUnknown()->unknown->unknown;
      *p.getUnknown()->unknown->nullable;  // TODO: fix false negative.
      *p.getUnknown();
      *p.getUnknown()->nullable;            // TODO: fix false negative.
      *p.getUnknown()->nullable->nullable;  // TODO: fix false negative.
      *p.getUnknown()->nullable->nonnull;   // TODO: fix false negative.

      *p.getNonnull()->getNonnull();
      *p.getNonnull()->getNonnull()->nullable0;  // TODO: fix false negative.
      *p.getNonnull()->getNonnull()->nullable1;  // TODO: fix false negative.
      *p.getNonnull()->getNullable();            // TODO: fix false negative.
      *p.getNonnull()->getNullable()->unknown;   // TODO: fix false negative.
      *p.getNonnull()->getNullable()->nullable;  // TODO: fix false negative.
      *p.getUnknown()->getUnknown();
      *p.getUnknown()->getUnknown()->unknown;
      *p.getUnknown()->getUnknown()->nullable;   // TODO: fix false negative.
      *p.getUnknown()->getNullable();            // TODO: fix false negative.
      *p.getUnknown()->getNullable()->nullable;  // TODO: fix false negative.
      *p.getUnknown()->getNullable()->nonnull;   // TODO: fix false negative.

      *p.getNonnull()->nonnull->getNullable0();  // TODO: fix false negative.
      *p.getNonnull()->nonnull->getNullable1();  // TODO: fix false negative.
      *p.getNonnull()->nullable->getUnknown();   // TODO: fix false negative.
      *p.getNonnull()->nullable->getNullable();  // TODO: fix false negative.
      *p.getUnknown()->unknown->getUnknown();
      *p.getUnknown()->unknown->getNullable();   // TODO: fix false negative.
      *p.getUnknown()->nullable->getNullable();  // TODO: fix false negative.
      *p.getUnknown()->nullable->getNonnull();   // TODO: fix false negative.

      *p.getNonnull()->getNonnull()->getNullable0();  // TODO: fix false
                                                      // negative.
      *p.getNonnull()->getNonnull()->getNullable1();  // TODO: fix false
                                                      // negative.
      *p.getNonnull()->getNullable()->getUnknown();   // TODO: fix false
                                                      // negative.
      *p.getNonnull()->getNullable()->getNullable();  // TODO: fix false
                                                      // negative.
      *p.getUnknown()->getUnknown()->getUnknown();
      *p.getUnknown()->getUnknown()->getNullable();   // TODO: fix false
                                                      // negative.
      *p.getUnknown()->getNullable()->getNullable();  // TODO: fix false
                                                      // negative.
      *p.getUnknown()->getNullable()->getNonnull();   // TODO: fix false
                                                      // negative.
    }
  )cc"));
}

TEST(PointerNullabilityTest, FunctionTemplates) {
  // Call expression that returns the first of two type parameters.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1>
    T0 returnFirst();

    void target() {
      *returnFirst<int *_Nonnull, int *_Nullable>();
      *returnFirst<int *, int *_Nullable>();
      *returnFirst<int *_Nullable, int *_Nonnull>();  // [[unsafe]]
    }
  )cc"));

  // Call expression that returns the second of two type parameters.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <typename T0, typename T1>
    T1 returnSecond();

    void target() {
      *returnSecond<int *_Nullable, int *_Nonnull>();
      *returnSecond<int *_Nullable, int *>();
      *returnSecond<int *, int *_Nullable>();  // [[unsafe]]
    }
  )cc"));

  // Call expression that has an int parameter and two type parameters,
  // returning the first type parameter.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <int I0, typename T1, typename T2>
    T1 fn3ArgWithInt();

    void target() {
      *fn3ArgWithInt<1, int *_Nullable, int *>();  // [[unsafe]]
      *fn3ArgWithInt<1, int *, int *_Nullable>();
    }
  )cc"));

  // Call expression with template parameter substituted with a concrete struct.
  EXPECT_TRUE(checkDiagnostics(R"cc(
    struct StructUnknownNullable {
      int *var0;
      int *_Nullable var1;

      int *getVar0();
      int *_Nullable getVar1();
    };

    template <typename T0, typename T1>
    T1 returnSecond();

    void target() {
      *returnSecond<StructUnknownNullable, int *_Nullable>();  // [[unsafe]]
      *returnSecond<int *_Nonnull, StructUnknownNullable *>();
      // TODO: The following line is a false positive. We correctly compute the
      // nullability of the expression, as confirmed by the call to
      // `assert_nullability`. However, the dataflow framework currently does
      // not model pointer values for this expression, which results in a (in
      // this case incorrect) nullptr value.
      *returnSecond<int *_Nonnull, StructUnknownNullable>()  // [[unsafe]]
           .var0;  // TODO: Fix false positive.
      __assert_nullability<NK_unspecified>(
          returnSecond<int *_Nonnull, StructUnknownNullable>().var0);
      *returnSecond<int *_Nonnull, StructUnknownNullable>().var1;  // [[unsafe]]
      *returnSecond<int *_Nonnull, StructUnknownNullable>().getVar0();
      *returnSecond<int *_Nonnull, StructUnknownNullable>()  // [[unsafe]]
           .getVar1();
    }
  )cc"));
}

TEST(PointerNullabilityTest, ParenTypeInTemplate) {
  checkDiagnostics(R"cc(
    template <typename T>
    struct S {
      T(a);
      T(*(b));

      T (*f)();
      T(((*g)))();
    };

    void targetNullable(S<int* _Nullable> s) {
      *s.a;   // [[unsafe]]
      **s.b;  // [[unsafe]]
      *s.f;
      *s.g;
      *s.f();  // TODO: fix false negative.
      *s.g();  // TODO: fix false negative.
    }

    void targetNonnull(S<int* _Nonnull> s) {
      *s.a;
      **s.b;
      *s.f;
      *s.g;
      *s.f();
      *s.g();
    }
  )cc");

  checkDiagnostics(R"cc(
    template <typename T>
    struct S {
      T arg;
    };

    void targetNullable(S<int* _Nullable>(a), S<int* _Nullable>(*(b)),
                        S<int(*_Nullable)> c, S<int*(*(*_Nullable))> d,
                        S<int* _Nullable (*)()> e) {
      *a.arg;    // [[unsafe]]
      *b->arg;   // [[unsafe]]
      *c.arg;    // [[unsafe]]
      ***d.arg;  // [[unsafe]]
      *e.arg;    // [[unsafe]]

      *e.arg();  // TODO: fix false negative.
    }

    void targetNonnull(S<int* _Nonnull>(a), S<int* _Nonnull>(*(b)),
                       S<int(*_Nonnull)> c, S<int*(*(*_Nonnull))> d,
                       S<int* _Nonnull (*)()> e) {
      *a.arg;
      *b->arg;
      *c.arg;
      ***d.arg;
      *e.arg;

      *e.arg();
    }
  )cc");
}

TEST(PointerNullabilityTest, PartialSpecialization) {
  EXPECT_TRUE(checkDiagnostics(R"cc(
    template <int, class>
    struct S;
    template <class T>
    struct S<0, T> {
      using Alias = T;
    };

    template <int i, class T>
    typename S<i, T>::Alias f(T);

    void target(int *p) { (void *)f<0>(p); }
  )cc"));
}

}  // namespace
}  // namespace nullability
}  // namespace tidy
}  // namespace clang