src/tint/fuzzers/tint_ast_fuzzer/mutations/replace_identifier_test.cc - dawn - Git at Google

 // Copyright 2021 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 "src/tint/fuzzers/tint_ast_fuzzer/mutations/replace_identifier.h"

 #include <string>

 #include "gtest/gtest.h"

 #include "src/tint/ast/call_statement.h"
 #include "src/tint/fuzzers/tint_ast_fuzzer/mutator.h"
 #include "src/tint/fuzzers/tint_ast_fuzzer/node_id_map.h"
 #include "src/tint/program_builder.h"
 #include "src/tint/reader/wgsl/parser.h"
 #include "src/tint/writer/wgsl/generator.h"

 namespace tint::fuzzers::ast_fuzzer {
 namespace {

 TEST(ReplaceIdentifierTest, NotApplicable_Simple) {
     std::string content = R"(
     fn main() {
       let a = 5;
       let c = 6;
       let b = a + 5;

       let d = vec2<i32>(1, 2);
       let e = d.x;
     }
   )";
     Source::File file("test.wgsl", content);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     const auto& main_fn_stmts = program.AST().Functions()[0]->body->statements;

     const auto* a_var = main_fn_stmts[0]->As<ast::VariableDeclStatement>()->variable;
     ASSERT_NE(a_var, nullptr);

     const auto* b_var = main_fn_stmts[2]->As<ast::VariableDeclStatement>()->variable;
     ASSERT_NE(b_var, nullptr);

     const auto* e_var = main_fn_stmts[4]->As<ast::VariableDeclStatement>()->variable;
     ASSERT_NE(e_var, nullptr);

     auto a_var_id = node_id_map.GetId(a_var);
     ASSERT_NE(a_var_id, 0);

     auto b_var_id = node_id_map.GetId(b_var);
     ASSERT_NE(b_var_id, 0);

     const auto* sum_expr = b_var->initializer->As<ast::BinaryExpression>();
     ASSERT_NE(sum_expr, nullptr);

     auto a_ident_id = node_id_map.GetId(sum_expr->lhs);
     ASSERT_NE(a_ident_id, 0);

     auto sum_expr_id = node_id_map.GetId(sum_expr);
     ASSERT_NE(sum_expr_id, 0);

     auto e_var_id = node_id_map.GetId(e_var);
     ASSERT_NE(e_var_id, 0);

     auto vec_member_access_id =
         node_id_map.GetId(e_var->initializer->As<ast::MemberAccessorExpression>()->member);
     ASSERT_NE(vec_member_access_id, 0);

     // use_id is invalid.
     EXPECT_FALSE(MutationReplaceIdentifier(0, a_var_id).IsApplicable(program, node_id_map));

     // use_id is not an identifier expression.
     EXPECT_FALSE(
         MutationReplaceIdentifier(sum_expr_id, a_var_id).IsApplicable(program, node_id_map));

     // use_id is an identifier but not a variable user.
     EXPECT_FALSE(MutationReplaceIdentifier(vec_member_access_id, a_var_id)
                      .IsApplicable(program, node_id_map));

     // replacement_id is invalid.
     EXPECT_FALSE(MutationReplaceIdentifier(a_ident_id, 0).IsApplicable(program, node_id_map));

     // replacement_id is not a variable.
     EXPECT_FALSE(
         MutationReplaceIdentifier(a_ident_id, sum_expr_id).IsApplicable(program, node_id_map));

     // Can't replace a variable with itself.
     EXPECT_FALSE(
         MutationReplaceIdentifier(a_ident_id, a_var_id).IsApplicable(program, node_id_map));

     // Replacement is not in scope.
     EXPECT_FALSE(
         MutationReplaceIdentifier(a_ident_id, b_var_id).IsApplicable(program, node_id_map));
     EXPECT_FALSE(
         MutationReplaceIdentifier(a_ident_id, e_var_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, GlobalVarNotInScope) {
     // Can't use the global variable if it's not in scope.
     std::string shader = R"(
 var<private> a: i32;

 fn f() {
   a = 3;
 }

 var<private> b: i32;
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto use_id = node_id_map.GetId(
         program.AST().Functions()[0]->body->statements[0]->As<ast::AssignmentStatement>()->lhs);
     ASSERT_NE(use_id, 0);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
     ASSERT_NE(replacement_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable1) {
     // Can't replace `a` with `b` since the store type is wrong (the same storage
     // class though).
     std::string shader = R"(
 var<private> a: i32;
 var<private> b: u32;
 fn f() {
   *&a = 4;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[0]
                                         ->As<ast::AssignmentStatement>()
                                         ->lhs->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable2) {
     // Can't replace `a` with `b` since the store type is wrong (the storage
     // class is different though).
     std::string shader = R"(
 var<private> a: i32;
 fn f() {
   var b: u32;
   *&a = 4;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST()
                                                 .Functions()[0]
                                                 ->body->statements[0]
                                                 ->As<ast::VariableDeclStatement>()
                                                 ->variable);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[1]
                                         ->As<ast::AssignmentStatement>()
                                         ->lhs->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable3) {
     // Can't replace `a` with `b` since the latter is not a reference (the store
     // type is the same, though).
     std::string shader = R"(
 var<private> a: i32;
 fn f() {
   let b = 45;
   *&a = 4;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST()
                                                 .Functions()[0]
                                                 ->body->statements[0]
                                                 ->As<ast::VariableDeclStatement>()
                                                 ->variable);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[1]
                                         ->As<ast::AssignmentStatement>()
                                         ->lhs->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable4) {
     // Can't replace `a` with `b` since the latter is not a reference (the store
     // type is the same, though).
     std::string shader = R"(
 var<private> a: i32;
 fn f(b: i32) {
   *&a = 4;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST().Functions()[0]->params[0]);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[0]
                                         ->As<ast::AssignmentStatement>()
                                         ->lhs->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable5) {
     // Can't replace `a` with `b` since the latter has a wrong access mode
     // (`read` for uniform address space).
     std::string shader = R"(
 struct S {
   a: i32
 }

 var<private> a: S;
 @group(1) @binding(1) var<uniform> b: S;
 fn f() {
   *&a = S(4);
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[0]
                                         ->As<ast::AssignmentStatement>()
                                         ->lhs->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable6) {
     // Can't replace `ptr_b` with `a` since the latter is not a pointer.
     std::string shader = R"(
 struct S {
   a: i32
 }

 var<private> a: S;
 @group(1) @binding(1) var<uniform> b: S;
 fn f() {
   let ptr_b = &b;
   *&a = *ptr_b;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[0]);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[1]
                                         ->As<ast::AssignmentStatement>()
                                         ->rhs->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable8) {
     // Can't replace `ptr_b` with `c` since the latter has a wrong access mode and
     // address space.
     std::string shader = R"(
 struct S {
   a: i32
 }

 var<private> a: S;
 @group(1) @binding(1) var<uniform> b: S;
 @group(1) @binding(2) var<storage, read_write> c: S;
 fn f() {
   let ptr_b = &b;
   *&a = *ptr_b;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[2]);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[1]
                                         ->As<ast::AssignmentStatement>()
                                         ->rhs->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable9) {
     // Can't replace `b` with `e` since the latter is not a reference.
     std::string shader = R"(
 struct S {
   a: i32
 }

 var<private> a: S;
 const e = 3;
 @group(1) @binding(1) var<uniform> b: S;
 fn f() {
   *&a = *&b;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[0]
                                         ->As<ast::AssignmentStatement>()
                                         ->rhs->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable10) {
     // Can't replace `b` with `e` since the latter has a wrong access mode.
     std::string shader = R"(
 struct S {
   a: i32
 }

 var<private> a: S;
 @group(0) @binding(0) var<storage, read_write> e: S;
 @group(1) @binding(1) var<uniform> b: S;
 fn f() {
   *&a = *&b;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
     ASSERT_NE(replacement_id, 0);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[0]
                                         ->As<ast::AssignmentStatement>()
                                         ->rhs->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, Applicable1) {
     // Can replace `a` with `b` (same address space).
     std::string shader = R"(
 fn f() {
   var b : vec2<u32>;
   var a = vec2<u32>(34u, 45u);
   (*&a)[1] = 3u;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[2]
                                         ->As<ast::AssignmentStatement>()
                                         ->lhs->As<ast::IndexAccessorExpression>()
                                         ->object->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     auto replacement_id = node_id_map.GetId(program.AST()
                                                 .Functions()[0]
                                                 ->body->statements[0]
                                                 ->As<ast::VariableDeclStatement>()
                                                 ->variable);
     ASSERT_NE(replacement_id, 0);

     ASSERT_TRUE(MaybeApplyMutation(program, MutationReplaceIdentifier(use_id, replacement_id),
                                    node_id_map, &program, &node_id_map, nullptr));
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     writer::wgsl::Options options;
     auto result = writer::wgsl::Generate(&program, options);
     ASSERT_TRUE(result.success) << result.error;

     std::string expected_shader = R"(fn f() {
   var b : vec2<u32>;
   var a = vec2<u32>(34u, 45u);
   (*(&(b)))[1] = 3u;
 }
 )";
     ASSERT_EQ(expected_shader, result.wgsl);
 }

 TEST(ReplaceIdentifierTest, Applicable2) {
     // Can replace `ptr_a` with `b` - the function parameter.
     std::string shader = R"(
 fn f(b: ptr<function, vec2<u32>>) {
   var a = vec2<u32>(34u, 45u);
   let ptr_a = &a;
   (*ptr_a)[1] = 3u;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[2]
                                         ->As<ast::AssignmentStatement>()
                                         ->lhs->As<ast::IndexAccessorExpression>()
                                         ->object->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     auto replacement_id = node_id_map.GetId(program.AST().Functions()[0]->params[0]);
     ASSERT_NE(replacement_id, 0);

     ASSERT_TRUE(MaybeApplyMutation(program, MutationReplaceIdentifier(use_id, replacement_id),
                                    node_id_map, &program, &node_id_map, nullptr));
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     writer::wgsl::Options options;
     auto result = writer::wgsl::Generate(&program, options);
     ASSERT_TRUE(result.success) << result.error;

     std::string expected_shader = R"(fn f(b : ptr<function, vec2<u32>>) {
   var a = vec2<u32>(34u, 45u);
   let ptr_a = &(a);
   (*(b))[1] = 3u;
 }
 )";
     ASSERT_EQ(expected_shader, result.wgsl);
 }

 TEST(ReplaceIdentifierTest, NotApplicable12) {
     // Can't replace `a` with `b` (both are references with different storage
     // class).
     std::string shader = R"(
 var<private> b : vec2<u32>;
 fn f() {
   var a = vec2<u32>(34u, 45u);
   (*&a)[1] = 3u;
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[1]
                                         ->As<ast::AssignmentStatement>()
                                         ->lhs->As<ast::IndexAccessorExpression>()
                                         ->object->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[0]);
     ASSERT_NE(replacement_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable13) {
     // Can't replace `a` with `b` (both are references with different storage
     // class).
     std::string shader = R"(
 var<private> b : vec2<u32>;
 fn f() {
   var a = vec2<u32>(34u, 45u);
   let c = (*&a)[1];
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[1]
                                         ->As<ast::VariableDeclStatement>()
                                         ->variable->initializer->As<ast::IndexAccessorExpression>()
                                         ->object->As<ast::UnaryOpExpression>()
                                         ->expr->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[0]);
     ASSERT_NE(replacement_id, 0);

     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 TEST(ReplaceIdentifierTest, NotApplicable14) {
     // Can't replace `ptr_a` with `ptr_b` (both are pointers with different
     // address space).
     std::string shader = R"(
 var<private> b: vec2<u32>;
 fn f() {
   var a = vec2<u32>(34u, 45u);
   let ptr_a = &a;
   let ptr_b = &b;
   let c = (*ptr_a)[1];
 }
 )";
     Source::File file("test.wgsl", shader);
     auto program = reader::wgsl::Parse(&file);
     ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

     NodeIdMap node_id_map(program);

     auto use_id = node_id_map.GetId(program.AST()
                                         .Functions()[0]
                                         ->body->statements[3]
                                         ->As<ast::VariableDeclStatement>()
                                         ->variable->initializer->As<ast::IndexAccessorExpression>()
                                         ->object->As<ast::UnaryOpExpression>()
                                         ->expr);
     ASSERT_NE(use_id, 0);

     auto replacement_id = node_id_map.GetId(program.AST()
                                                 .Functions()[0]
                                                 ->body->statements[2]
                                                 ->As<ast::VariableDeclStatement>()
                                                 ->variable);
     ASSERT_NE(replacement_id, 0);
     ASSERT_FALSE(
         MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
 }

 }  // namespace
 }  // namespace tint::fuzzers::ast_fuzzer
	// Copyright 2021 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 "src/tint/fuzzers/tint_ast_fuzzer/mutations/replace_identifier.h"

	#include <string>

	#include "gtest/gtest.h"

	#include "src/tint/ast/call_statement.h"
	#include "src/tint/fuzzers/tint_ast_fuzzer/mutator.h"
	#include "src/tint/fuzzers/tint_ast_fuzzer/node_id_map.h"
	#include "src/tint/program_builder.h"
	#include "src/tint/reader/wgsl/parser.h"
	#include "src/tint/writer/wgsl/generator.h"

	namespace tint::fuzzers::ast_fuzzer {
	namespace {

	TEST(ReplaceIdentifierTest, NotApplicable_Simple) {
	std::string content = R"(
	fn main() {
	let a = 5;
	let c = 6;
	let b = a + 5;

	let d = vec2<i32>(1, 2);
	let e = d.x;
	}
	)";
	Source::File file("test.wgsl", content);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	const auto& main_fn_stmts = program.AST().Functions()[0]->body->statements;

	const auto* a_var = main_fn_stmts[0]->As<ast::VariableDeclStatement>()->variable;
	ASSERT_NE(a_var, nullptr);

	const auto* b_var = main_fn_stmts[2]->As<ast::VariableDeclStatement>()->variable;
	ASSERT_NE(b_var, nullptr);

	const auto* e_var = main_fn_stmts[4]->As<ast::VariableDeclStatement>()->variable;
	ASSERT_NE(e_var, nullptr);

	auto a_var_id = node_id_map.GetId(a_var);
	ASSERT_NE(a_var_id, 0);

	auto b_var_id = node_id_map.GetId(b_var);
	ASSERT_NE(b_var_id, 0);

	const auto* sum_expr = b_var->initializer->As<ast::BinaryExpression>();
	ASSERT_NE(sum_expr, nullptr);

	auto a_ident_id = node_id_map.GetId(sum_expr->lhs);
	ASSERT_NE(a_ident_id, 0);

	auto sum_expr_id = node_id_map.GetId(sum_expr);
	ASSERT_NE(sum_expr_id, 0);

	auto e_var_id = node_id_map.GetId(e_var);
	ASSERT_NE(e_var_id, 0);

	auto vec_member_access_id =
	node_id_map.GetId(e_var->initializer->As<ast::MemberAccessorExpression>()->member);
	ASSERT_NE(vec_member_access_id, 0);

	// use_id is invalid.
	EXPECT_FALSE(MutationReplaceIdentifier(0, a_var_id).IsApplicable(program, node_id_map));

	// use_id is not an identifier expression.
	EXPECT_FALSE(
	MutationReplaceIdentifier(sum_expr_id, a_var_id).IsApplicable(program, node_id_map));

	// use_id is an identifier but not a variable user.
	EXPECT_FALSE(MutationReplaceIdentifier(vec_member_access_id, a_var_id)
	.IsApplicable(program, node_id_map));

	// replacement_id is invalid.
	EXPECT_FALSE(MutationReplaceIdentifier(a_ident_id, 0).IsApplicable(program, node_id_map));

	// replacement_id is not a variable.
	EXPECT_FALSE(
	MutationReplaceIdentifier(a_ident_id, sum_expr_id).IsApplicable(program, node_id_map));

	// Can't replace a variable with itself.
	EXPECT_FALSE(
	MutationReplaceIdentifier(a_ident_id, a_var_id).IsApplicable(program, node_id_map));

	// Replacement is not in scope.
	EXPECT_FALSE(
	MutationReplaceIdentifier(a_ident_id, b_var_id).IsApplicable(program, node_id_map));
	EXPECT_FALSE(
	MutationReplaceIdentifier(a_ident_id, e_var_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, GlobalVarNotInScope) {
	// Can't use the global variable if it's not in scope.
	std::string shader = R"(
	var<private> a: i32;

	fn f() {
	a = 3;
	}

	var<private> b: i32;
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto use_id = node_id_map.GetId(
	program.AST().Functions()[0]->body->statements[0]->As<ast::AssignmentStatement>()->lhs);
	ASSERT_NE(use_id, 0);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
	ASSERT_NE(replacement_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable1) {
	// Can't replace `a` with `b` since the store type is wrong (the same storage
	// class though).
	std::string shader = R"(
	var<private> a: i32;
	var<private> b: u32;
	fn f() {
	*&a = 4;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[0]
	->As<ast::AssignmentStatement>()
	->lhs->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable2) {
	// Can't replace `a` with `b` since the store type is wrong (the storage
	// class is different though).
	std::string shader = R"(
	var<private> a: i32;
	fn f() {
	var b: u32;
	*&a = 4;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[0]
	->As<ast::VariableDeclStatement>()
	->variable);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[1]
	->As<ast::AssignmentStatement>()
	->lhs->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable3) {
	// Can't replace `a` with `b` since the latter is not a reference (the store
	// type is the same, though).
	std::string shader = R"(
	var<private> a: i32;
	fn f() {
	let b = 45;
	*&a = 4;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[0]
	->As<ast::VariableDeclStatement>()
	->variable);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[1]
	->As<ast::AssignmentStatement>()
	->lhs->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable4) {
	// Can't replace `a` with `b` since the latter is not a reference (the store
	// type is the same, though).
	std::string shader = R"(
	var<private> a: i32;
	fn f(b: i32) {
	*&a = 4;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST().Functions()[0]->params[0]);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[0]
	->As<ast::AssignmentStatement>()
	->lhs->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable5) {
	// Can't replace `a` with `b` since the latter has a wrong access mode
	// (`read` for uniform address space).
	std::string shader = R"(
	struct S {
	a: i32
	}

	var<private> a: S;
	@group(1) @binding(1) var<uniform> b: S;
	fn f() {
	*&a = S(4);
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[0]
	->As<ast::AssignmentStatement>()
	->lhs->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable6) {
	// Can't replace `ptr_b` with `a` since the latter is not a pointer.
	std::string shader = R"(
	struct S {
	a: i32
	}

	var<private> a: S;
	@group(1) @binding(1) var<uniform> b: S;
	fn f() {
	let ptr_b = &b;
	&a = ptr_b;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[0]);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[1]
	->As<ast::AssignmentStatement>()
	->rhs->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable8) {
	// Can't replace `ptr_b` with `c` since the latter has a wrong access mode and
	// address space.
	std::string shader = R"(
	struct S {
	a: i32
	}

	var<private> a: S;
	@group(1) @binding(1) var<uniform> b: S;
	@group(1) @binding(2) var<storage, read_write> c: S;
	fn f() {
	let ptr_b = &b;
	&a = ptr_b;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[2]);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[1]
	->As<ast::AssignmentStatement>()
	->rhs->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable9) {
	// Can't replace `b` with `e` since the latter is not a reference.
	std::string shader = R"(
	struct S {
	a: i32
	}

	var<private> a: S;
	const e = 3;
	@group(1) @binding(1) var<uniform> b: S;
	fn f() {
	&a = &b;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[0]
	->As<ast::AssignmentStatement>()
	->rhs->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable10) {
	// Can't replace `b` with `e` since the latter has a wrong access mode.
	std::string shader = R"(
	struct S {
	a: i32
	}

	var<private> a: S;
	@group(0) @binding(0) var<storage, read_write> e: S;
	@group(1) @binding(1) var<uniform> b: S;
	fn f() {
	&a = &b;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[1]);
	ASSERT_NE(replacement_id, 0);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[0]
	->As<ast::AssignmentStatement>()
	->rhs->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, Applicable1) {
	// Can replace `a` with `b` (same address space).
	std::string shader = R"(
	fn f() {
	var b : vec2<u32>;
	var a = vec2<u32>(34u, 45u);
	(*&a)[1] = 3u;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[2]
	->As<ast::AssignmentStatement>()
	->lhs->As<ast::IndexAccessorExpression>()
	->object->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	auto replacement_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[0]
	->As<ast::VariableDeclStatement>()
	->variable);
	ASSERT_NE(replacement_id, 0);

	ASSERT_TRUE(MaybeApplyMutation(program, MutationReplaceIdentifier(use_id, replacement_id),
	node_id_map, &program, &node_id_map, nullptr));
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	writer::wgsl::Options options;
	auto result = writer::wgsl::Generate(&program, options);
	ASSERT_TRUE(result.success) << result.error;

	std::string expected_shader = R"(fn f() {
	var b : vec2<u32>;
	var a = vec2<u32>(34u, 45u);
	(*(&(b)))[1] = 3u;
	}
	)";
	ASSERT_EQ(expected_shader, result.wgsl);
	}

	TEST(ReplaceIdentifierTest, Applicable2) {
	// Can replace `ptr_a` with `b` - the function parameter.
	std::string shader = R"(
	fn f(b: ptr<function, vec2<u32>>) {
	var a = vec2<u32>(34u, 45u);
	let ptr_a = &a;
	(*ptr_a)[1] = 3u;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[2]
	->As<ast::AssignmentStatement>()
	->lhs->As<ast::IndexAccessorExpression>()
	->object->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	auto replacement_id = node_id_map.GetId(program.AST().Functions()[0]->params[0]);
	ASSERT_NE(replacement_id, 0);

	ASSERT_TRUE(MaybeApplyMutation(program, MutationReplaceIdentifier(use_id, replacement_id),
	node_id_map, &program, &node_id_map, nullptr));
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	writer::wgsl::Options options;
	auto result = writer::wgsl::Generate(&program, options);
	ASSERT_TRUE(result.success) << result.error;

	std::string expected_shader = R"(fn f(b : ptr<function, vec2<u32>>) {
	var a = vec2<u32>(34u, 45u);
	let ptr_a = &(a);
	(*(b))[1] = 3u;
	}
	)";
	ASSERT_EQ(expected_shader, result.wgsl);
	}

	TEST(ReplaceIdentifierTest, NotApplicable12) {
	// Can't replace `a` with `b` (both are references with different storage
	// class).
	std::string shader = R"(
	var<private> b : vec2<u32>;
	fn f() {
	var a = vec2<u32>(34u, 45u);
	(*&a)[1] = 3u;
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[1]
	->As<ast::AssignmentStatement>()
	->lhs->As<ast::IndexAccessorExpression>()
	->object->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[0]);
	ASSERT_NE(replacement_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable13) {
	// Can't replace `a` with `b` (both are references with different storage
	// class).
	std::string shader = R"(
	var<private> b : vec2<u32>;
	fn f() {
	var a = vec2<u32>(34u, 45u);
	let c = (*&a)[1];
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[1]
	->As<ast::VariableDeclStatement>()
	->variable->initializer->As<ast::IndexAccessorExpression>()
	->object->As<ast::UnaryOpExpression>()
	->expr->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	auto replacement_id = node_id_map.GetId(program.AST().GlobalVariables()[0]);
	ASSERT_NE(replacement_id, 0);

	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	TEST(ReplaceIdentifierTest, NotApplicable14) {
	// Can't replace `ptr_a` with `ptr_b` (both are pointers with different
	// address space).
	std::string shader = R"(
	var<private> b: vec2<u32>;
	fn f() {
	var a = vec2<u32>(34u, 45u);
	let ptr_a = &a;
	let ptr_b = &b;
	let c = (*ptr_a)[1];
	}
	)";
	Source::File file("test.wgsl", shader);
	auto program = reader::wgsl::Parse(&file);
	ASSERT_TRUE(program.IsValid()) << program.Diagnostics().str();

	NodeIdMap node_id_map(program);

	auto use_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[3]
	->As<ast::VariableDeclStatement>()
	->variable->initializer->As<ast::IndexAccessorExpression>()
	->object->As<ast::UnaryOpExpression>()
	->expr);
	ASSERT_NE(use_id, 0);

	auto replacement_id = node_id_map.GetId(program.AST()
	.Functions()[0]
	->body->statements[2]
	->As<ast::VariableDeclStatement>()
	->variable);
	ASSERT_NE(replacement_id, 0);
	ASSERT_FALSE(
	MutationReplaceIdentifier(use_id, replacement_id).IsApplicable(program, node_id_map));
	}

	} // namespace
	} // namespace tint::fuzzers::ast_fuzzer