// Copyright 2020 The Tint Authors.
//
// Licensed under the Apache License, Version 2.0 (the "License");
// you may not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
//     http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing, software
// distributed under the License is distributed on an "AS IS" BASIS,
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
// See the License for the specific language governing permissions and
// limitations under the License.

#include "gtest/gtest.h"
#include "src/ast/assignment_statement.h"
#include "src/ast/binary_expression.h"
#include "src/ast/binding_decoration.h"
#include "src/ast/call_expression.h"
#include "src/ast/decorated_variable.h"
#include "src/ast/float_literal.h"
#include "src/ast/function.h"
#include "src/ast/identifier_expression.h"
#include "src/ast/if_statement.h"
#include "src/ast/location_decoration.h"
#include "src/ast/member_accessor_expression.h"
#include "src/ast/module.h"
#include "src/ast/return_statement.h"
#include "src/ast/scalar_constructor_expression.h"
#include "src/ast/set_decoration.h"
#include "src/ast/sint_literal.h"
#include "src/ast/type/array_type.h"
#include "src/ast/type/f32_type.h"
#include "src/ast/type/i32_type.h"
#include "src/ast/type/vector_type.h"
#include "src/ast/type/void_type.h"
#include "src/ast/variable.h"
#include "src/ast/variable_decl_statement.h"
#include "src/context.h"
#include "src/type_determiner.h"
#include "src/writer/msl/generator_impl.h"

namespace tint {
namespace writer {
namespace msl {
namespace {

using MslGeneratorImplTest = testing::Test;

TEST_F(MslGeneratorImplTest, Emit_Function) {
  ast::type::VoidType void_type;

  auto func = std::make_unique<ast::Function>("my_func", ast::VariableList{},
                                              &void_type);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  ast::Module m;
  m.AddFunction(std::move(func));

  GeneratorImpl g(&m);
  g.increment_indent();

  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

  void my_func() {
    return;
  }

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_Name_Collision) {
  ast::type::VoidType void_type;

  auto func =
      std::make_unique<ast::Function>("main", ast::VariableList{}, &void_type);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  ast::Module m;
  m.AddFunction(std::move(func));

  GeneratorImpl g(&m);
  g.increment_indent();

  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

  void main_tint_0() {
    return;
  }

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_WithParams) {
  ast::type::F32Type f32;
  ast::type::I32Type i32;

  ast::VariableList params;
  params.push_back(
      std::make_unique<ast::Variable>("a", ast::StorageClass::kNone, &f32));
  params.push_back(
      std::make_unique<ast::Variable>("b", ast::StorageClass::kNone, &i32));

  ast::type::VoidType void_type;
  auto func =
      std::make_unique<ast::Function>("my_func", std::move(params), &void_type);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  ast::Module m;
  m.AddFunction(std::move(func));

  GeneratorImpl g(&m);
  g.increment_indent();

  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

  void my_func(float a, int b) {
    return;
  }

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_EntryPoint_NoName) {
  ast::type::VoidType void_type;

  auto func = std::make_unique<ast::Function>("frag_main", ast::VariableList{},
                                              &void_type);
  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment, "",
                                              "frag_main");

  ast::Module m;
  m.AddFunction(std::move(func));
  m.AddEntryPoint(std::move(ep));

  GeneratorImpl g(&m);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

fragment void frag_main() {
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_EntryPoint_WithInOutVars) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;

  auto foo_var = std::make_unique<ast::DecoratedVariable>(
      std::make_unique<ast::Variable>("foo", ast::StorageClass::kInput, &f32));

  ast::VariableDecorationList decos;
  decos.push_back(std::make_unique<ast::LocationDecoration>(0));
  foo_var->set_decorations(std::move(decos));

  auto bar_var = std::make_unique<ast::DecoratedVariable>(
      std::make_unique<ast::Variable>("bar", ast::StorageClass::kOutput, &f32));
  decos.push_back(std::make_unique<ast::LocationDecoration>(1));
  bar_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(foo_var.get());
  td.RegisterVariableForTesting(bar_var.get());

  mod.AddGlobalVariable(std::move(foo_var));
  mod.AddGlobalVariable(std::move(bar_var));

  ast::VariableList params;
  auto func = std::make_unique<ast::Function>("frag_main", std::move(params),
                                              &void_type);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("bar"),
      std::make_unique<ast::IdentifierExpression>("foo")));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  mod.AddFunction(std::move(func));

  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment, "",
                                              "frag_main");
  mod.AddEntryPoint(std::move(ep));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

struct frag_main_in {
  float foo [[user(locn0)]];
};

struct frag_main_out {
  float bar [[color(1)]];
};

fragment frag_main_out frag_main(frag_main_in tint_in [[stage_in]]) {
  frag_main_out tint_out = {};
  tint_out.bar = tint_in.foo;
  return tint_out;
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_EntryPoint_WithInOut_Builtins) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;
  ast::type::VectorType vec4(&f32, 4);

  auto coord_var =
      std::make_unique<ast::DecoratedVariable>(std::make_unique<ast::Variable>(
          "coord", ast::StorageClass::kInput, &vec4));

  ast::VariableDecorationList decos;
  decos.push_back(
      std::make_unique<ast::BuiltinDecoration>(ast::Builtin::kFragCoord));
  coord_var->set_decorations(std::move(decos));

  auto depth_var =
      std::make_unique<ast::DecoratedVariable>(std::make_unique<ast::Variable>(
          "depth", ast::StorageClass::kOutput, &f32));
  decos.push_back(
      std::make_unique<ast::BuiltinDecoration>(ast::Builtin::kFragDepth));
  depth_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(coord_var.get());
  td.RegisterVariableForTesting(depth_var.get());

  mod.AddGlobalVariable(std::move(coord_var));
  mod.AddGlobalVariable(std::move(depth_var));

  ast::VariableList params;
  auto func = std::make_unique<ast::Function>("frag_main", std::move(params),
                                              &void_type);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("depth"),
      std::make_unique<ast::MemberAccessorExpression>(
          std::make_unique<ast::IdentifierExpression>("coord"),
          std::make_unique<ast::IdentifierExpression>("x"))));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  mod.AddFunction(std::move(func));

  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment, "",
                                              "frag_main");
  mod.AddEntryPoint(std::move(ep));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

struct frag_main_out {
  float depth [[depth(any)]];
};

fragment frag_main_out frag_main(float4 coord [[position]]) {
  frag_main_out tint_out = {};
  tint_out.depth = coord.x;
  return tint_out;
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_EntryPoint_With_Uniform) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;
  ast::type::VectorType vec4(&f32, 4);

  auto coord_var =
      std::make_unique<ast::DecoratedVariable>(std::make_unique<ast::Variable>(
          "coord", ast::StorageClass::kUniform, &vec4));

  ast::VariableDecorationList decos;
  decos.push_back(std::make_unique<ast::BindingDecoration>(0));
  decos.push_back(std::make_unique<ast::SetDecoration>(1));
  coord_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(coord_var.get());

  mod.AddGlobalVariable(std::move(coord_var));

  ast::VariableList params;
  auto func = std::make_unique<ast::Function>("frag_main", std::move(params),
                                              &void_type);

  auto var =
      std::make_unique<ast::Variable>("v", ast::StorageClass::kFunction, &f32);
  var->set_constructor(std::make_unique<ast::MemberAccessorExpression>(
      std::make_unique<ast::IdentifierExpression>("coord"),
      std::make_unique<ast::IdentifierExpression>("x")));

  ast::StatementList body;
  body.push_back(std::make_unique<ast::VariableDeclStatement>(std::move(var)));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  mod.AddFunction(std::move(func));

  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment, "",
                                              "frag_main");
  mod.AddEntryPoint(std::move(ep));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

fragment void frag_main(constant float4& coord [[buffer(0)]]) {
  float v = coord.x;
  return;
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_EntryPoint_With_StorageBuffer) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;
  ast::type::VectorType vec4(&f32, 4);

  auto coord_var =
      std::make_unique<ast::DecoratedVariable>(std::make_unique<ast::Variable>(
          "coord", ast::StorageClass::kStorageBuffer, &vec4));

  ast::VariableDecorationList decos;
  decos.push_back(std::make_unique<ast::BindingDecoration>(0));
  decos.push_back(std::make_unique<ast::SetDecoration>(1));
  coord_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(coord_var.get());

  mod.AddGlobalVariable(std::move(coord_var));

  ast::VariableList params;
  auto func = std::make_unique<ast::Function>("frag_main", std::move(params),
                                              &void_type);

  auto var =
      std::make_unique<ast::Variable>("v", ast::StorageClass::kFunction, &f32);
  var->set_constructor(std::make_unique<ast::MemberAccessorExpression>(
      std::make_unique<ast::IdentifierExpression>("coord"),
      std::make_unique<ast::IdentifierExpression>("x")));

  ast::StatementList body;
  body.push_back(std::make_unique<ast::VariableDeclStatement>(std::move(var)));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  mod.AddFunction(std::move(func));

  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment, "",
                                              "frag_main");
  mod.AddEntryPoint(std::move(ep));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

fragment void frag_main(device float4& coord [[buffer(0)]]) {
  float v = coord.x;
  return;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_Function_Called_By_EntryPoints_WithLocationGlobals_And_Params) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;

  auto foo_var = std::make_unique<ast::DecoratedVariable>(
      std::make_unique<ast::Variable>("foo", ast::StorageClass::kInput, &f32));

  ast::VariableDecorationList decos;
  decos.push_back(std::make_unique<ast::LocationDecoration>(0));
  foo_var->set_decorations(std::move(decos));

  auto bar_var = std::make_unique<ast::DecoratedVariable>(
      std::make_unique<ast::Variable>("bar", ast::StorageClass::kOutput, &f32));
  decos.push_back(std::make_unique<ast::LocationDecoration>(1));
  bar_var->set_decorations(std::move(decos));

  auto val_var = std::make_unique<ast::DecoratedVariable>(
      std::make_unique<ast::Variable>("val", ast::StorageClass::kOutput, &f32));
  decos.push_back(std::make_unique<ast::LocationDecoration>(0));
  val_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(foo_var.get());
  td.RegisterVariableForTesting(bar_var.get());
  td.RegisterVariableForTesting(val_var.get());

  mod.AddGlobalVariable(std::move(foo_var));
  mod.AddGlobalVariable(std::move(bar_var));
  mod.AddGlobalVariable(std::move(val_var));

  ast::VariableList params;
  params.push_back(std::make_unique<ast::Variable>(
      "param", ast::StorageClass::kFunction, &f32));
  auto sub_func =
      std::make_unique<ast::Function>("sub_func", std::move(params), &f32);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("bar"),
      std::make_unique<ast::IdentifierExpression>("foo")));
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("val"),
      std::make_unique<ast::IdentifierExpression>("param")));
  body.push_back(std::make_unique<ast::ReturnStatement>(
      std::make_unique<ast::IdentifierExpression>("foo")));
  sub_func->set_body(std::move(body));

  mod.AddFunction(std::move(sub_func));

  auto func_1 = std::make_unique<ast::Function>("frag_1_main",
                                                std::move(params), &void_type);

  ast::ExpressionList expr;
  expr.push_back(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("bar"),
      std::make_unique<ast::CallExpression>(
          std::make_unique<ast::IdentifierExpression>("sub_func"),
          std::move(expr))));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func_1->set_body(std::move(body));

  mod.AddFunction(std::move(func_1));

  auto ep1 = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment,
                                               "ep_1", "frag_1_main");
  mod.AddEntryPoint(std::move(ep1));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

struct ep_1_in {
  float foo [[user(locn0)]];
};

struct ep_1_out {
  float bar [[color(1)]];
  float val [[color(0)]];
};

float sub_func_ep_1(thread ep_1_in& tint_in, thread ep_1_out& tint_out, float param) {
  tint_out.bar = tint_in.foo;
  tint_out.val = param;
  return tint_in.foo;
}

fragment ep_1_out ep_1(ep_1_in tint_in [[stage_in]]) {
  ep_1_out tint_out = {};
  tint_out.bar = sub_func_ep_1(tint_in, tint_out, 1.00000000f);
  return tint_out;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_Function_Called_By_EntryPoints_WithBuiltinGlobals_And_Params) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;
  ast::type::VectorType vec4(&f32, 4);

  auto coord_var =
      std::make_unique<ast::DecoratedVariable>(std::make_unique<ast::Variable>(
          "coord", ast::StorageClass::kInput, &vec4));

  ast::VariableDecorationList decos;
  decos.push_back(
      std::make_unique<ast::BuiltinDecoration>(ast::Builtin::kFragCoord));
  coord_var->set_decorations(std::move(decos));

  auto depth_var =
      std::make_unique<ast::DecoratedVariable>(std::make_unique<ast::Variable>(
          "depth", ast::StorageClass::kOutput, &f32));
  decos.push_back(
      std::make_unique<ast::BuiltinDecoration>(ast::Builtin::kFragDepth));
  depth_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(coord_var.get());
  td.RegisterVariableForTesting(depth_var.get());

  mod.AddGlobalVariable(std::move(coord_var));
  mod.AddGlobalVariable(std::move(depth_var));

  ast::VariableList params;
  params.push_back(std::make_unique<ast::Variable>(
      "param", ast::StorageClass::kFunction, &f32));
  auto sub_func =
      std::make_unique<ast::Function>("sub_func", std::move(params), &f32);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("depth"),
      std::make_unique<ast::MemberAccessorExpression>(
          std::make_unique<ast::IdentifierExpression>("coord"),
          std::make_unique<ast::IdentifierExpression>("x"))));
  body.push_back(std::make_unique<ast::ReturnStatement>(
      std::make_unique<ast::IdentifierExpression>("param")));
  sub_func->set_body(std::move(body));

  mod.AddFunction(std::move(sub_func));

  auto func_1 = std::make_unique<ast::Function>("frag_1_main",
                                                std::move(params), &void_type);

  ast::ExpressionList expr;
  expr.push_back(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("depth"),
      std::make_unique<ast::CallExpression>(
          std::make_unique<ast::IdentifierExpression>("sub_func"),
          std::move(expr))));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func_1->set_body(std::move(body));

  mod.AddFunction(std::move(func_1));

  auto ep1 = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment,
                                               "ep_1", "frag_1_main");
  mod.AddEntryPoint(std::move(ep1));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

struct ep_1_out {
  float depth [[depth(any)]];
};

float sub_func_ep_1(thread ep_1_out& tint_out, thread float4& coord, float param) {
  tint_out.depth = coord.x;
  return param;
}

fragment ep_1_out ep_1(float4 coord [[position]]) {
  ep_1_out tint_out = {};
  tint_out.depth = sub_func_ep_1(tint_out, coord, 1.00000000f);
  return tint_out;
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_Called_By_EntryPoint_With_Uniform) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;
  ast::type::VectorType vec4(&f32, 4);

  auto coord_var =
      std::make_unique<ast::DecoratedVariable>(std::make_unique<ast::Variable>(
          "coord", ast::StorageClass::kUniform, &vec4));

  ast::VariableDecorationList decos;
  decos.push_back(std::make_unique<ast::BindingDecoration>(0));
  decos.push_back(std::make_unique<ast::SetDecoration>(1));
  coord_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(coord_var.get());

  mod.AddGlobalVariable(std::move(coord_var));

  ast::VariableList params;
  params.push_back(std::make_unique<ast::Variable>(
      "param", ast::StorageClass::kFunction, &f32));
  auto sub_func =
      std::make_unique<ast::Function>("sub_func", std::move(params), &f32);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::ReturnStatement>(
      std::make_unique<ast::MemberAccessorExpression>(
          std::make_unique<ast::IdentifierExpression>("coord"),
          std::make_unique<ast::IdentifierExpression>("x"))));
  sub_func->set_body(std::move(body));

  mod.AddFunction(std::move(sub_func));

  auto func = std::make_unique<ast::Function>("frag_main", std::move(params),
                                              &void_type);

  ast::ExpressionList expr;
  expr.push_back(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));

  auto var =
      std::make_unique<ast::Variable>("v", ast::StorageClass::kFunction, &f32);
  var->set_constructor(std::make_unique<ast::CallExpression>(
      std::make_unique<ast::IdentifierExpression>("sub_func"),
      std::move(expr)));

  body.push_back(std::make_unique<ast::VariableDeclStatement>(std::move(var)));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  mod.AddFunction(std::move(func));

  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment, "",
                                              "frag_main");
  mod.AddEntryPoint(std::move(ep));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

float sub_func(constant float4& coord, float param) {
  return coord.x;
}

fragment void frag_main(constant float4& coord [[buffer(0)]]) {
  float v = sub_func(coord, 1.00000000f);
  return;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_Function_Called_By_EntryPoint_With_StorageBuffer) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;
  ast::type::VectorType vec4(&f32, 4);

  auto coord_var =
      std::make_unique<ast::DecoratedVariable>(std::make_unique<ast::Variable>(
          "coord", ast::StorageClass::kStorageBuffer, &vec4));

  ast::VariableDecorationList decos;
  decos.push_back(std::make_unique<ast::BindingDecoration>(0));
  decos.push_back(std::make_unique<ast::SetDecoration>(1));
  coord_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(coord_var.get());

  mod.AddGlobalVariable(std::move(coord_var));

  ast::VariableList params;
  params.push_back(std::make_unique<ast::Variable>(
      "param", ast::StorageClass::kFunction, &f32));
  auto sub_func =
      std::make_unique<ast::Function>("sub_func", std::move(params), &f32);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::ReturnStatement>(
      std::make_unique<ast::MemberAccessorExpression>(
          std::make_unique<ast::IdentifierExpression>("coord"),
          std::make_unique<ast::IdentifierExpression>("x"))));
  sub_func->set_body(std::move(body));

  mod.AddFunction(std::move(sub_func));

  auto func = std::make_unique<ast::Function>("frag_main", std::move(params),
                                              &void_type);

  ast::ExpressionList expr;
  expr.push_back(std::make_unique<ast::ScalarConstructorExpression>(
      std::make_unique<ast::FloatLiteral>(&f32, 1.0f)));

  auto var =
      std::make_unique<ast::Variable>("v", ast::StorageClass::kFunction, &f32);
  var->set_constructor(std::make_unique<ast::CallExpression>(
      std::make_unique<ast::IdentifierExpression>("sub_func"),
      std::move(expr)));

  body.push_back(std::make_unique<ast::VariableDeclStatement>(std::move(var)));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  mod.AddFunction(std::move(func));

  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment, "",
                                              "frag_main");
  mod.AddEntryPoint(std::move(ep));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

float sub_func(device float4& coord, float param) {
  return coord.x;
}

fragment void frag_main(device float4& coord [[buffer(0)]]) {
  float v = sub_func(coord, 1.00000000f);
  return;
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_Called_Two_EntryPoints_WithGlobals) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;

  auto foo_var = std::make_unique<ast::DecoratedVariable>(
      std::make_unique<ast::Variable>("foo", ast::StorageClass::kInput, &f32));

  ast::VariableDecorationList decos;
  decos.push_back(std::make_unique<ast::LocationDecoration>(0));
  foo_var->set_decorations(std::move(decos));

  auto bar_var = std::make_unique<ast::DecoratedVariable>(
      std::make_unique<ast::Variable>("bar", ast::StorageClass::kOutput, &f32));
  decos.push_back(std::make_unique<ast::LocationDecoration>(1));
  bar_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(foo_var.get());
  td.RegisterVariableForTesting(bar_var.get());

  mod.AddGlobalVariable(std::move(foo_var));
  mod.AddGlobalVariable(std::move(bar_var));

  ast::VariableList params;
  auto sub_func =
      std::make_unique<ast::Function>("sub_func", std::move(params), &f32);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("bar"),
      std::make_unique<ast::IdentifierExpression>("foo")));
  body.push_back(std::make_unique<ast::ReturnStatement>(
      std::make_unique<ast::IdentifierExpression>("foo")));
  sub_func->set_body(std::move(body));

  mod.AddFunction(std::move(sub_func));

  auto func_1 = std::make_unique<ast::Function>("frag_1_main",
                                                std::move(params), &void_type);

  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("bar"),
      std::make_unique<ast::CallExpression>(
          std::make_unique<ast::IdentifierExpression>("sub_func"),
          ast::ExpressionList{})));
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func_1->set_body(std::move(body));

  mod.AddFunction(std::move(func_1));

  auto ep1 = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment,
                                               "ep_1", "frag_1_main");
  auto ep2 = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment,
                                               "ep_2", "frag_1_main");
  mod.AddEntryPoint(std::move(ep1));
  mod.AddEntryPoint(std::move(ep2));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

struct ep_1_in {
  float foo [[user(locn0)]];
};

struct ep_1_out {
  float bar [[color(1)]];
};

struct ep_2_in {
  float foo [[user(locn0)]];
};

struct ep_2_out {
  float bar [[color(1)]];
};

float sub_func_ep_1(thread ep_1_in& tint_in, thread ep_1_out& tint_out) {
  tint_out.bar = tint_in.foo;
  return tint_in.foo;
}

float sub_func_ep_2(thread ep_2_in& tint_in, thread ep_2_out& tint_out) {
  tint_out.bar = tint_in.foo;
  return tint_in.foo;
}

fragment ep_1_out ep_1(ep_1_in tint_in [[stage_in]]) {
  ep_1_out tint_out = {};
  tint_out.bar = sub_func_ep_1(tint_in, tint_out);
  return tint_out;
}

fragment ep_2_out ep_2(ep_2_in tint_in [[stage_in]]) {
  ep_2_out tint_out = {};
  tint_out.bar = sub_func_ep_2(tint_in, tint_out);
  return tint_out;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_Function_EntryPoints_WithGlobal_Nested_Return) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;
  ast::type::I32Type i32;

  auto bar_var = std::make_unique<ast::DecoratedVariable>(
      std::make_unique<ast::Variable>("bar", ast::StorageClass::kOutput, &f32));
  ast::VariableDecorationList decos;
  decos.push_back(std::make_unique<ast::LocationDecoration>(1));
  bar_var->set_decorations(std::move(decos));

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);
  td.RegisterVariableForTesting(bar_var.get());
  mod.AddGlobalVariable(std::move(bar_var));

  ast::VariableList params;
  auto func_1 = std::make_unique<ast::Function>("frag_1_main",
                                                std::move(params), &void_type);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::AssignmentStatement>(
      std::make_unique<ast::IdentifierExpression>("bar"),
      std::make_unique<ast::ScalarConstructorExpression>(
          std::make_unique<ast::FloatLiteral>(&f32, 1.0f))));

  ast::StatementList list;
  list.push_back(std::make_unique<ast::ReturnStatement>());
  body.push_back(std::make_unique<ast::IfStatement>(
      std::make_unique<ast::BinaryExpression>(
          ast::BinaryOp::kEqual,
          std::make_unique<ast::ScalarConstructorExpression>(
              std::make_unique<ast::SintLiteral>(&i32, 1)),
          std::make_unique<ast::ScalarConstructorExpression>(
              std::make_unique<ast::SintLiteral>(&i32, 1))),
      std::move(list)));

  body.push_back(std::make_unique<ast::ReturnStatement>());
  func_1->set_body(std::move(body));

  mod.AddFunction(std::move(func_1));

  auto ep1 = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment,
                                               "ep_1", "frag_1_main");
  mod.AddEntryPoint(std::move(ep1));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

struct ep_1_out {
  float bar [[color(1)]];
};

fragment ep_1_out ep_1() {
  ep_1_out tint_out = {};
  tint_out.bar = 1.00000000f;
  if ((1 == 1)) {
    return tint_out;
  }
  return tint_out;
}

)");
}

TEST_F(MslGeneratorImplTest,
       Emit_Function_Called_Two_EntryPoints_WithoutGlobals) {
  ast::type::VoidType void_type;
  ast::type::F32Type f32;

  Context ctx;
  ast::Module mod;
  TypeDeterminer td(&ctx, &mod);

  ast::VariableList params;
  auto sub_func =
      std::make_unique<ast::Function>("sub_func", std::move(params), &f32);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::ReturnStatement>(
      std::make_unique<ast::ScalarConstructorExpression>(
          std::make_unique<ast::FloatLiteral>(&f32, 1.0))));
  sub_func->set_body(std::move(body));

  mod.AddFunction(std::move(sub_func));

  auto func_1 = std::make_unique<ast::Function>("frag_1_main",
                                                std::move(params), &void_type);

  body.push_back(std::make_unique<ast::VariableDeclStatement>(
      std::make_unique<ast::Variable>("foo", ast::StorageClass::kFunction,
                                      &f32)));
  body.back()->AsVariableDecl()->variable()->set_constructor(
      std::make_unique<ast::CallExpression>(
          std::make_unique<ast::IdentifierExpression>("sub_func"),
          ast::ExpressionList{}));

  body.push_back(std::make_unique<ast::ReturnStatement>());
  func_1->set_body(std::move(body));

  mod.AddFunction(std::move(func_1));

  auto ep1 = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment,
                                               "ep_1", "frag_1_main");
  auto ep2 = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kFragment,
                                               "ep_2", "frag_1_main");
  mod.AddEntryPoint(std::move(ep1));
  mod.AddEntryPoint(std::move(ep2));

  ASSERT_TRUE(td.Determine()) << td.error();

  GeneratorImpl g(&mod);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

float sub_func() {
  return 1.00000000f;
}

fragment void ep_1() {
  float foo = sub_func();
  return;
}

fragment void ep_2() {
  float foo = sub_func();
  return;
}

)");
}
TEST_F(MslGeneratorImplTest, Emit_Function_EntryPoint_WithName) {
  ast::type::VoidType void_type;

  auto func = std::make_unique<ast::Function>("comp_main", ast::VariableList{},
                                              &void_type);
  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kCompute,
                                              "my_main", "comp_main");

  ast::Module m;
  m.AddFunction(std::move(func));
  m.AddEntryPoint(std::move(ep));

  GeneratorImpl g(&m);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

kernel void my_main() {
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_EntryPoint_WithNameCollision) {
  ast::type::VoidType void_type;

  auto func = std::make_unique<ast::Function>("comp_main", ast::VariableList{},
                                              &void_type);
  auto ep = std::make_unique<ast::EntryPoint>(ast::PipelineStage::kCompute,
                                              "main", "comp_main");

  ast::Module m;
  m.AddFunction(std::move(func));
  m.AddEntryPoint(std::move(ep));

  GeneratorImpl g(&m);
  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

kernel void main_tint_0() {
}

)");
}

TEST_F(MslGeneratorImplTest, Emit_Function_WithArrayParams) {
  ast::type::F32Type f32;
  ast::type::ArrayType ary(&f32, 5);

  ast::VariableList params;
  params.push_back(
      std::make_unique<ast::Variable>("a", ast::StorageClass::kNone, &ary));

  ast::type::VoidType void_type;
  auto func =
      std::make_unique<ast::Function>("my_func", std::move(params), &void_type);

  ast::StatementList body;
  body.push_back(std::make_unique<ast::ReturnStatement>());
  func->set_body(std::move(body));

  ast::Module m;
  m.AddFunction(std::move(func));

  GeneratorImpl g(&m);
  g.increment_indent();

  ASSERT_TRUE(g.Generate()) << g.error();
  EXPECT_EQ(g.result(), R"(#include <metal_stdlib>

  void my_func(float a[5]) {
    return;
  }

)");
}

}  // namespace
}  // namespace msl
}  // namespace writer
}  // namespace tint