compiler/utils/assembler_test_base.h - LeafOS-Project/android_art - Gitiles

 /*
  * Copyright (C) 2014 The Android Open Source Project
  *
  * 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.
  */

 #ifndef ART_COMPILER_UTILS_ASSEMBLER_TEST_BASE_H_
 #define ART_COMPILER_UTILS_ASSEMBLER_TEST_BASE_H_

 #include <sys/stat.h>
 #include <cstdio>
 #include <cstdlib>
 #include <fstream>
 #include <iterator>
 #include <regex>

 #include "android-base/strings.h"

 #include "base/macros.h"
 #include "base/os.h"
 #include "base/utils.h"
 #include "common_runtime_test.h"  // For ScratchDir.
 #include "elf/elf_builder.h"
 #include "elf/elf_debug_reader.h"
 #include "exec_utils.h"
 #include "stream/file_output_stream.h"

 namespace art HIDDEN {

 // If you want to take a look at the differences between the ART assembler and clang,
 // set this flag to true. The disassembled files will then remain in the tmp directory.
 static constexpr bool kKeepDisassembledFiles = false;

 // We put this into a class as gtests are self-contained, so this helper needs to be in an h-file.
 class AssemblerTestBase : public testing::Test {
  public:
   AssemblerTestBase() {}

   void SetUp() override {
     // Fake a runtime test for ScratchDir.
     CommonArtTest::SetUpAndroidRootEnvVars();
     CommonRuntimeTest::SetUpAndroidDataDir(android_data_);
     scratch_dir_.emplace(/*keep_files=*/ kKeepDisassembledFiles);
   }

   void TearDown() override {
     // We leave temporaries in case this failed so we can debug issues.
     CommonRuntimeTest::TearDownAndroidDataDir(android_data_, false);
   }

   // This is intended to be run as a test.
   bool CheckTools() {
     for (const std::string& cmd : { GetAssemblerCommand()[0], GetDisassemblerCommand()[0] }) {
       if (!OS::FileExists(cmd.c_str())) {
         LOG(ERROR) << "Could not find " << cmd;
         return false;
       }
     }
     return true;
   }

   // Driver() assembles and compares the results. If the results are not equal and we have a
   // disassembler, disassemble both and check whether they have the same mnemonics (in which case
   // we just warn).
   void Driver(const std::vector<uint8_t>& art_code,
               const std::string& assembly_text,
               const std::string& test_name) {
     ASSERT_NE(assembly_text.length(), 0U) << "Empty assembly";
     InstructionSet isa = GetIsa();
     auto test_path = [&](const char* ext) { return scratch_dir_->GetPath() + test_name + ext; };

     // Create file containing the reference source code.
     std::string ref_asm_file = test_path(".ref.S");
     WriteFile(ref_asm_file, assembly_text.data(), assembly_text.size());

     // Assemble reference object file.
     std::string ref_obj_file = test_path(".ref.o");
     ASSERT_TRUE(Assemble(ref_asm_file, ref_obj_file));

     // Read the code produced by assembler from the ELF file.
     std::vector<uint8_t> ref_code;
     if (Is64BitInstructionSet(isa)) {
       ReadElf</*IsElf64=*/true>(ref_obj_file, &ref_code);
     } else {
       ReadElf</*IsElf64=*/false>(ref_obj_file, &ref_code);
     }

     // Compare the ART generated code to the expected reference code.
     if (art_code == ref_code) {
       return;  // Success!
     }

     // Create ELF file containing the ART code.
     std::string art_obj_file = test_path(".art.o");
     if (Is64BitInstructionSet(isa)) {
       WriteElf</*IsElf64=*/true>(art_obj_file, isa, art_code);
     } else {
       WriteElf</*IsElf64=*/false>(art_obj_file, isa, art_code);
     }

     // Disassemble both object files, and check that the outputs match.
     std::string art_disassembly;
     ASSERT_TRUE(Disassemble(art_obj_file, &art_disassembly));
     art_disassembly = Replace(art_disassembly, art_obj_file, test_path("<extension-redacted>"));
     art_disassembly = StripComments(art_disassembly);
     std::string ref_disassembly;
     ASSERT_TRUE(Disassemble(ref_obj_file, &ref_disassembly));
     ref_disassembly = Replace(ref_disassembly, ref_obj_file, test_path("<extension-redacted>"));
     ref_disassembly = StripComments(ref_disassembly);
     ASSERT_EQ(art_disassembly, ref_disassembly) << "Outputs (and disassembly) not identical.";

     // ART produced different (but valid) code than the reference assembler, report it.
     if (art_code.size() > ref_code.size()) {
       EXPECT_TRUE(false) << "ART code is larger then the reference code, but the disassembly"
           "of machine code is equal: this means that ART is generating sub-optimal encoding! "
           "ART code size=" << art_code.size() << ", reference code size=" << ref_code.size();
     } else if (art_code.size() < ref_code.size()) {
       EXPECT_TRUE(false) << "ART code is smaller than the reference code. Too good to be true?";
     } else {
       LOG(INFO) << "Reference assembler chose a different encoding than ART (of the same size)";
     }
   }

  protected:
   virtual InstructionSet GetIsa() = 0;

   std::string FindTool(const std::string& tool_name) {
     return CommonArtTest::GetAndroidTool(tool_name.c_str(), GetIsa());
   }

   virtual std::vector<std::string> GetAssemblerCommand() {
     InstructionSet isa = GetIsa();
     switch (isa) {
       case InstructionSet::kX86:
         return {FindTool("clang"), "--compile", "-target", "i386-linux-gnu"};
       case InstructionSet::kX86_64:
         return {FindTool("clang"), "--compile", "-target", "x86_64-linux-gnu"};
       default:
         LOG(FATAL) << "Unknown instruction set: " << isa;
         UNREACHABLE();
     }
   }

   virtual std::vector<std::string> GetDisassemblerCommand() {
     switch (GetIsa()) {
       case InstructionSet::kThumb2:
         return {FindTool("llvm-objdump"),
                 "--disassemble",
                 "--no-print-imm-hex",
                 "--triple",
                 "thumbv7a-linux-gnueabi"};
       default:
         return {
             FindTool("llvm-objdump"), "--disassemble", "--no-print-imm-hex", "--no-show-raw-insn"};
     }
   }

   bool Assemble(const std::string& asm_file, const std::string& obj_file) {
     std::vector<std::string> args = GetAssemblerCommand();
     args.insert(args.end(), {"-o", obj_file, asm_file});
     std::string output;
     bool ok = CommonArtTestImpl::ForkAndExec(args, [](){ return true; }, &output).StandardSuccess();
     if (!ok) {
       LOG(ERROR) << "Assembler error:\n" << output;
     }
     return ok;
   }

   bool Disassemble(const std::string& obj_file, std::string* output) {
     std::vector<std::string> args = GetDisassemblerCommand();
     args.insert(args.end(), {obj_file});
     bool ok = CommonArtTestImpl::ForkAndExec(args, [](){ return true; }, output).StandardSuccess();
     if (!ok) {
       LOG(ERROR) << "Disassembler error:\n" << *output;
     }
     *output = Replace(*output, "\t", " ");
     return ok;
   }

   std::vector<uint8_t> ReadFile(const std::string& filename) {
     std::unique_ptr<File> file(OS::OpenFileForReading(filename.c_str()));
     CHECK(file.get() != nullptr);
     std::vector<uint8_t> data(file->GetLength());
     bool success = file->ReadFully(&data[0], data.size());
     CHECK(success) << filename;
     return data;
   }

   void WriteFile(const std::string& filename, const void* data, size_t size) {
     std::unique_ptr<File> file(OS::CreateEmptyFile(filename.c_str()));
     CHECK(file.get() != nullptr);
     bool success = file->WriteFully(data, size);
     CHECK(success) << filename;
     CHECK_EQ(file->FlushClose(), 0);
   }

   // Helper method which reads the content of .text section from ELF file.
   template<bool IsElf64>
   void ReadElf(const std::string& filename, /*out*/ std::vector<uint8_t>* code) {
     using ElfTypes = typename std::conditional<IsElf64, ElfTypes64, ElfTypes32>::type;
     std::vector<uint8_t> data = ReadFile(filename);
     ElfDebugReader<ElfTypes> reader((ArrayRef<const uint8_t>(data)));
     const typename ElfTypes::Shdr* text = reader.GetSection(".text");
     CHECK(text != nullptr);
     *code = std::vector<uint8_t>(&data[text->sh_offset], &data[text->sh_offset + text->sh_size]);
   }

   // Helper method to create an ELF file containing only the given code in the .text section.
   template<bool IsElf64>
   void WriteElf(const std::string& filename, InstructionSet isa, const std::vector<uint8_t>& code) {
     using ElfTypes = typename std::conditional<IsElf64, ElfTypes64, ElfTypes32>::type;
     std::unique_ptr<File> file(OS::CreateEmptyFile(filename.c_str()));
     CHECK(file.get() != nullptr);
     FileOutputStream out(file.get());
     std::unique_ptr<ElfBuilder<ElfTypes>> builder(new ElfBuilder<ElfTypes>(isa, &out));
     builder->Start(/* write_program_headers= */ false);
     builder->GetText()->Start();
     builder->GetText()->WriteFully(code.data(), code.size());
     builder->GetText()->End();
     builder->End();
     CHECK(builder->Good());
     CHECK_EQ(file->Close(), 0);
   }

   static std::string GetRootPath() {
     // 1) Check ANDROID_BUILD_TOP
     char* build_top = getenv("ANDROID_BUILD_TOP");
     if (build_top != nullptr) {
       return std::string(build_top) + "/";
     }

     // 2) Do cwd
     char temp[1024];
     return getcwd(temp, 1024) ? std::string(temp) + "/" : std::string("");
   }

   std::string Replace(const std::string& str, const std::string& from, const std::string& to) {
     std::string output;
     size_t pos = 0;
     for (auto match = str.find(from); match != str.npos; match = str.find(from, pos)) {
       output += str.substr(pos, match - pos);
       output += to;
       pos = match + from.size();
     }
     output += str.substr(pos, str.size() - pos);
     return output;
   }

   // Remove comments emitted by objdump.
   std::string StripComments(const std::string& str) {
     return std::regex_replace(str, std::regex(" +# .*"), "");
   }

   std::optional<ScratchDir> scratch_dir_;
   std::string android_data_;
   DISALLOW_COPY_AND_ASSIGN(AssemblerTestBase);
 };

 }  // namespace art

 #endif  // ART_COMPILER_UTILS_ASSEMBLER_TEST_BASE_H_
	/*
	* Copyright (C) 2014 The Android Open Source Project
	*
	* 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.
	*/

	#ifndef ART_COMPILER_UTILS_ASSEMBLER_TEST_BASE_H_
	#define ART_COMPILER_UTILS_ASSEMBLER_TEST_BASE_H_

	#include <sys/stat.h>
	#include <cstdio>
	#include <cstdlib>
	#include <fstream>
	#include <iterator>
	#include <regex>

	#include "android-base/strings.h"

	#include "base/macros.h"
	#include "base/os.h"
	#include "base/utils.h"
	#include "common_runtime_test.h" // For ScratchDir.
	#include "elf/elf_builder.h"
	#include "elf/elf_debug_reader.h"
	#include "exec_utils.h"
	#include "stream/file_output_stream.h"

	namespace art HIDDEN {

	// If you want to take a look at the differences between the ART assembler and clang,
	// set this flag to true. The disassembled files will then remain in the tmp directory.
	static constexpr bool kKeepDisassembledFiles = false;

	// We put this into a class as gtests are self-contained, so this helper needs to be in an h-file.
	class AssemblerTestBase : public testing::Test {
	public:
	AssemblerTestBase() {}

	void SetUp() override {
	// Fake a runtime test for ScratchDir.
	CommonArtTest::SetUpAndroidRootEnvVars();
	CommonRuntimeTest::SetUpAndroidDataDir(android_data_);
	scratch_dir_.emplace(/keep_files=/ kKeepDisassembledFiles);
	}

	void TearDown() override {
	// We leave temporaries in case this failed so we can debug issues.
	CommonRuntimeTest::TearDownAndroidDataDir(android_data_, false);
	}

	// This is intended to be run as a test.
	bool CheckTools() {
	for (const std::string& cmd : { GetAssemblerCommand()[0], GetDisassemblerCommand()[0] }) {
	if (!OS::FileExists(cmd.c_str())) {
	LOG(ERROR) << "Could not find " << cmd;
	return false;
	}
	}
	return true;
	}

	// Driver() assembles and compares the results. If the results are not equal and we have a
	// disassembler, disassemble both and check whether they have the same mnemonics (in which case
	// we just warn).
	void Driver(const std::vector<uint8_t>& art_code,
	const std::string& assembly_text,
	const std::string& test_name) {
	ASSERT_NE(assembly_text.length(), 0U) << "Empty assembly";
	InstructionSet isa = GetIsa();
	auto test_path = [&](const char* ext) { return scratch_dir_->GetPath() + test_name + ext; };

	// Create file containing the reference source code.
	std::string ref_asm_file = test_path(".ref.S");
	WriteFile(ref_asm_file, assembly_text.data(), assembly_text.size());

	// Assemble reference object file.
	std::string ref_obj_file = test_path(".ref.o");
	ASSERT_TRUE(Assemble(ref_asm_file, ref_obj_file));

	// Read the code produced by assembler from the ELF file.
	std::vector<uint8_t> ref_code;
	if (Is64BitInstructionSet(isa)) {
	ReadElf</IsElf64=/true>(ref_obj_file, &ref_code);
	} else {
	ReadElf</IsElf64=/false>(ref_obj_file, &ref_code);
	}

	// Compare the ART generated code to the expected reference code.
	if (art_code == ref_code) {
	return; // Success!
	}

	// Create ELF file containing the ART code.
	std::string art_obj_file = test_path(".art.o");
	if (Is64BitInstructionSet(isa)) {
	WriteElf</IsElf64=/true>(art_obj_file, isa, art_code);
	} else {
	WriteElf</IsElf64=/false>(art_obj_file, isa, art_code);
	}

	// Disassemble both object files, and check that the outputs match.
	std::string art_disassembly;
	ASSERT_TRUE(Disassemble(art_obj_file, &art_disassembly));
	art_disassembly = Replace(art_disassembly, art_obj_file, test_path("<extension-redacted>"));
	art_disassembly = StripComments(art_disassembly);
	std::string ref_disassembly;
	ASSERT_TRUE(Disassemble(ref_obj_file, &ref_disassembly));
	ref_disassembly = Replace(ref_disassembly, ref_obj_file, test_path("<extension-redacted>"));
	ref_disassembly = StripComments(ref_disassembly);
	ASSERT_EQ(art_disassembly, ref_disassembly) << "Outputs (and disassembly) not identical.";

	// ART produced different (but valid) code than the reference assembler, report it.
	if (art_code.size() > ref_code.size()) {
	EXPECT_TRUE(false) << "ART code is larger then the reference code, but the disassembly"
	"of machine code is equal: this means that ART is generating sub-optimal encoding! "
	"ART code size=" << art_code.size() << ", reference code size=" << ref_code.size();
	} else if (art_code.size() < ref_code.size()) {
	EXPECT_TRUE(false) << "ART code is smaller than the reference code. Too good to be true?";
	} else {
	LOG(INFO) << "Reference assembler chose a different encoding than ART (of the same size)";
	}
	}

	protected:
	virtual InstructionSet GetIsa() = 0;

	std::string FindTool(const std::string& tool_name) {
	return CommonArtTest::GetAndroidTool(tool_name.c_str(), GetIsa());
	}

	virtual std::vector<std::string> GetAssemblerCommand() {
	InstructionSet isa = GetIsa();
	switch (isa) {
	case InstructionSet::kX86:
	return {FindTool("clang"), "--compile", "-target", "i386-linux-gnu"};
	case InstructionSet::kX86_64:
	return {FindTool("clang"), "--compile", "-target", "x86_64-linux-gnu"};
	default:
	LOG(FATAL) << "Unknown instruction set: " << isa;
	UNREACHABLE();
	}
	}

	virtual std::vector<std::string> GetDisassemblerCommand() {
	switch (GetIsa()) {
	case InstructionSet::kThumb2:
	return {FindTool("llvm-objdump"),
	"--disassemble",
	"--no-print-imm-hex",
	"--triple",
	"thumbv7a-linux-gnueabi"};
	default:
	return {
	FindTool("llvm-objdump"), "--disassemble", "--no-print-imm-hex", "--no-show-raw-insn"};
	}
	}

	bool Assemble(const std::string& asm_file, const std::string& obj_file) {
	std::vector<std::string> args = GetAssemblerCommand();
	args.insert(args.end(), {"-o", obj_file, asm_file});
	std::string output;
	bool ok = CommonArtTestImpl::ForkAndExec(args, [](){ return true; }, &output).StandardSuccess();
	if (!ok) {
	LOG(ERROR) << "Assembler error:\n" << output;
	}
	return ok;
	}

	bool Disassemble(const std::string& obj_file, std::string* output) {
	std::vector<std::string> args = GetDisassemblerCommand();
	args.insert(args.end(), {obj_file});
	bool ok = CommonArtTestImpl::ForkAndExec(args, [](){ return true; }, output).StandardSuccess();
	if (!ok) {
	LOG(ERROR) << "Disassembler error:\n" << *output;
	}
	output = Replace(output, "\t", " ");
	return ok;
	}

	std::vector<uint8_t> ReadFile(const std::string& filename) {
	std::unique_ptr<File> file(OS::OpenFileForReading(filename.c_str()));
	CHECK(file.get() != nullptr);
	std::vector<uint8_t> data(file->GetLength());
	bool success = file->ReadFully(&data[0], data.size());
	CHECK(success) << filename;
	return data;
	}

	void WriteFile(const std::string& filename, const void* data, size_t size) {
	std::unique_ptr<File> file(OS::CreateEmptyFile(filename.c_str()));
	CHECK(file.get() != nullptr);
	bool success = file->WriteFully(data, size);
	CHECK(success) << filename;
	CHECK_EQ(file->FlushClose(), 0);
	}

	// Helper method which reads the content of .text section from ELF file.
	template<bool IsElf64>
	void ReadElf(const std::string& filename, /out/ std::vector<uint8_t>* code) {
	using ElfTypes = typename std::conditional<IsElf64, ElfTypes64, ElfTypes32>::type;
	std::vector<uint8_t> data = ReadFile(filename);
	ElfDebugReader<ElfTypes> reader((ArrayRef<const uint8_t>(data)));
	const typename ElfTypes::Shdr* text = reader.GetSection(".text");
	CHECK(text != nullptr);
	*code = std::vector<uint8_t>(&data[text->sh_offset], &data[text->sh_offset + text->sh_size]);
	}

	// Helper method to create an ELF file containing only the given code in the .text section.
	template<bool IsElf64>
	void WriteElf(const std::string& filename, InstructionSet isa, const std::vector<uint8_t>& code) {
	using ElfTypes = typename std::conditional<IsElf64, ElfTypes64, ElfTypes32>::type;
	std::unique_ptr<File> file(OS::CreateEmptyFile(filename.c_str()));
	CHECK(file.get() != nullptr);
	FileOutputStream out(file.get());
	std::unique_ptr<ElfBuilder<ElfTypes>> builder(new ElfBuilder<ElfTypes>(isa, &out));
	builder->Start(/* write_program_headers= */ false);
	builder->GetText()->Start();
	builder->GetText()->WriteFully(code.data(), code.size());
	builder->GetText()->End();
	builder->End();
	CHECK(builder->Good());
	CHECK_EQ(file->Close(), 0);
	}

	static std::string GetRootPath() {
	// 1) Check ANDROID_BUILD_TOP
	char* build_top = getenv("ANDROID_BUILD_TOP");
	if (build_top != nullptr) {
	return std::string(build_top) + "/";
	}

	// 2) Do cwd
	char temp[1024];
	return getcwd(temp, 1024) ? std::string(temp) + "/" : std::string("");
	}

	std::string Replace(const std::string& str, const std::string& from, const std::string& to) {
	std::string output;
	size_t pos = 0;
	for (auto match = str.find(from); match != str.npos; match = str.find(from, pos)) {
	output += str.substr(pos, match - pos);
	output += to;
	pos = match + from.size();
	}
	output += str.substr(pos, str.size() - pos);
	return output;
	}

	// Remove comments emitted by objdump.
	std::string StripComments(const std::string& str) {
	return std::regex_replace(str, std::regex(" +# .*"), "");
	}

	std::optional<ScratchDir> scratch_dir_;
	std::string android_data_;
	DISALLOW_COPY_AND_ASSIGN(AssemblerTestBase);
	};

	} // namespace art

	#endif // ART_COMPILER_UTILS_ASSEMBLER_TEST_BASE_H_