compiler/utils/assembler_test.h - platform/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_H_
 #define ART_COMPILER_UTILS_ASSEMBLER_TEST_H_

 #include "assembler.h"

 #include "common_runtime_test.h"  // For ScratchFile

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

 namespace art {

 // Use a glocal static variable to keep the same name for all test data. Else we'll just spam the
 // temp directory.
 static std::string tmpnam_;

 template<typename Ass, typename Reg, typename Imm>
 class AssemblerTest : public testing::Test {
  public:
   Ass* GetAssembler() {
     return assembler_.get();
   }

   typedef std::string (*TestFn)(Ass* assembler);

   void DriverFn(TestFn f, std::string test_name) {
     Driver(f(assembler_.get()), test_name);
   }

   // This driver assumes the assembler has already been called.
   void DriverStr(std::string assembly_string, std::string test_name) {
     Driver(assembly_string, test_name);
   }

   std::string RepeatR(void (Ass::*f)(Reg), std::string fmt) {
     const std::vector<Reg*> registers = GetRegisters();
     std::string str;
     for (auto reg : registers) {
       (assembler_.get()->*f)(*reg);
       std::string base = fmt;

       size_t reg_index = base.find("{reg}");
       if (reg_index != std::string::npos) {
         std::ostringstream sreg;
         sreg << *reg;
         std::string reg_string = sreg.str();
         base.replace(reg_index, 5, reg_string);
       }

       if (str.size() > 0) {
         str += "\n";
       }
       str += base;
     }
     // Add a newline at the end.
     str += "\n";
     return str;
   }

   std::string RepeatRR(void (Ass::*f)(Reg, Reg), std::string fmt) {
     const std::vector<Reg*> registers = GetRegisters();
     std::string str;
     for (auto reg1 : registers) {
       for (auto reg2 : registers) {
         (assembler_.get()->*f)(*reg1, *reg2);
         std::string base = fmt;

         size_t reg1_index = base.find("{reg1}");
         if (reg1_index != std::string::npos) {
           std::ostringstream sreg;
           sreg << *reg1;
           std::string reg_string = sreg.str();
           base.replace(reg1_index, 6, reg_string);
         }

         size_t reg2_index = base.find("{reg2}");
         if (reg2_index != std::string::npos) {
           std::ostringstream sreg;
           sreg << *reg2;
           std::string reg_string = sreg.str();
           base.replace(reg2_index, 6, reg_string);
         }

         if (str.size() > 0) {
           str += "\n";
         }
         str += base;
       }
     }
     // Add a newline at the end.
     str += "\n";
     return str;
   }

   std::string RepeatRI(void (Ass::*f)(Reg, const Imm&), size_t imm_bytes, std::string fmt) {
     const std::vector<Reg*> registers = GetRegisters();
     std::string str;
     std::vector<int64_t> imms = CreateImmediateValues(imm_bytes);
     for (auto reg : registers) {
       for (int64_t imm : imms) {
         Imm* new_imm = CreateImmediate(imm);
         (assembler_.get()->*f)(*reg, *new_imm);
         delete new_imm;
         std::string base = fmt;

         size_t reg_index = base.find("{reg}");
         if (reg_index != std::string::npos) {
           std::ostringstream sreg;
           sreg << *reg;
           std::string reg_string = sreg.str();
           base.replace(reg_index, 5, reg_string);
         }

         size_t imm_index = base.find("{imm}");
         if (imm_index != std::string::npos) {
           std::ostringstream sreg;
           sreg << imm;
           std::string imm_string = sreg.str();
           base.replace(imm_index, 5, imm_string);
         }

         if (str.size() > 0) {
           str += "\n";
         }
         str += base;
       }
     }
     // Add a newline at the end.
     str += "\n";
     return str;
   }

   std::string RepeatI(void (Ass::*f)(const Imm&), size_t imm_bytes, std::string fmt) {
     std::string str;
     std::vector<int64_t> imms = CreateImmediateValues(imm_bytes);
     for (int64_t imm : imms) {
       Imm* new_imm = CreateImmediate(imm);
       (assembler_.get()->*f)(*new_imm);
       delete new_imm;
       std::string base = fmt;

       size_t imm_index = base.find("{imm}");
       if (imm_index != std::string::npos) {
         std::ostringstream sreg;
         sreg << imm;
         std::string imm_string = sreg.str();
         base.replace(imm_index, 5, imm_string);
       }

       if (str.size() > 0) {
         str += "\n";
       }
       str += base;
     }
     // Add a newline at the end.
     str += "\n";
     return str;
   }

   // This is intended to be run as a test.
   bool CheckTools() {
     if (!FileExists(GetAssemblerCommand())) {
       return false;
     }
     LOG(INFO) << "Chosen assembler command: " << GetAssemblerCommand();

     if (!FileExists(GetObjdumpCommand())) {
       return false;
     }
     LOG(INFO) << "Chosen objdump command: " << GetObjdumpCommand();

     // Disassembly is optional.
     std::string disassembler = GetDisassembleCommand();
     if (disassembler.length() != 0) {
       if (!FileExists(disassembler)) {
         return false;
       }
       LOG(INFO) << "Chosen disassemble command: " << GetDisassembleCommand();
     } else {
       LOG(INFO) << "No disassembler given.";
     }

     return true;
   }

  protected:
   void SetUp() OVERRIDE {
     assembler_.reset(new Ass());

     // Fake a runtime test for ScratchFile
     CommonRuntimeTest::SetUpAndroidData(android_data_);

     SetUpHelpers();
   }

   void TearDown() OVERRIDE {
     // We leave temporaries in case this failed so we can debug issues.
     CommonRuntimeTest::TearDownAndroidData(android_data_, false);
     tmpnam_ = "";
   }

   // Override this to set up any architecture-specific things, e.g., register vectors.
   virtual void SetUpHelpers() {}

   virtual std::vector<Reg*> GetRegisters() = 0;

   // Get the typically used name for this architecture, e.g., aarch64, x86_64, ...
   virtual std::string GetArchitectureString() = 0;

   // Get the name of the assembler, e.g., "as" by default.
   virtual std::string GetAssemblerCmdName() {
     return "as";
   }

   // Switches to the assembler command. Default none.
   virtual std::string GetAssemblerParameters() {
     return "";
   }

   // Return the host assembler command for this test.
   virtual std::string GetAssemblerCommand() {
     // Already resolved it once?
     if (resolved_assembler_cmd_.length() != 0) {
       return resolved_assembler_cmd_;
     }

     std::string line = FindTool(GetAssemblerCmdName());
     if (line.length() == 0) {
       return line;
     }

     resolved_assembler_cmd_ = line + GetAssemblerParameters();

     return line;
   }

   // Get the name of the objdump, e.g., "objdump" by default.
   virtual std::string GetObjdumpCmdName() {
     return "objdump";
   }

   // Switches to the objdump command. Default is " -h".
   virtual std::string GetObjdumpParameters() {
     return " -h";
   }

   // Return the host objdump command for this test.
   virtual std::string GetObjdumpCommand() {
     // Already resolved it once?
     if (resolved_objdump_cmd_.length() != 0) {
       return resolved_objdump_cmd_;
     }

     std::string line = FindTool(GetObjdumpCmdName());
     if (line.length() == 0) {
       return line;
     }

     resolved_objdump_cmd_ = line + GetObjdumpParameters();

     return line;
   }

   // Get the name of the objdump, e.g., "objdump" by default.
   virtual std::string GetDisassembleCmdName() {
     return "objdump";
   }

   // Switches to the objdump command. As it's a binary, one needs to push the architecture and
   // such to objdump, so it's architecture-specific and there is no default.
   virtual std::string GetDisassembleParameters() = 0;

   // Return the host disassembler command for this test.
   virtual std::string GetDisassembleCommand() {
     // Already resolved it once?
     if (resolved_disassemble_cmd_.length() != 0) {
       return resolved_disassemble_cmd_;
     }

     std::string line = FindTool(GetDisassembleCmdName());
     if (line.length() == 0) {
       return line;
     }

     resolved_disassemble_cmd_ = line + GetDisassembleParameters();

     return line;
   }

   // Create a couple of immediate values up to the number of bytes given.
   virtual std::vector<int64_t> CreateImmediateValues(size_t imm_bytes) {
     std::vector<int64_t> res;
     res.push_back(0);
     res.push_back(-1);
     res.push_back(0x12);
     if (imm_bytes >= 2) {
       res.push_back(0x1234);
       res.push_back(-0x1234);
       if (imm_bytes >= 4) {
         res.push_back(0x12345678);
         res.push_back(-0x12345678);
         if (imm_bytes >= 6) {
           res.push_back(0x123456789ABC);
           res.push_back(-0x123456789ABC);
           if (imm_bytes >= 8) {
             res.push_back(0x123456789ABCDEF0);
             res.push_back(-0x123456789ABCDEF0);
           }
         }
       }
     }
     return res;
   }

   // Create an immediate from the specific value.
   virtual Imm* CreateImmediate(int64_t imm_value) = 0;

  private:
   // 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(std::string assembly_text, std::string test_name) {
     EXPECT_NE(assembly_text.length(), 0U) << "Empty assembly";

     NativeAssemblerResult res;
     Compile(assembly_text, &res, test_name);

     EXPECT_TRUE(res.ok) << res.error_msg;
     if (!res.ok) {
       // No way of continuing.
       return;
     }

     size_t cs = assembler_->CodeSize();
     std::unique_ptr<std::vector<uint8_t>> data(new std::vector<uint8_t>(cs));
     MemoryRegion code(&(*data)[0], data->size());
     assembler_->FinalizeInstructions(code);

     if (*data == *res.code) {
       Clean(&res);
     } else {
       if (DisassembleBinaries(*data, *res.code, test_name)) {
         if (data->size() > res.code->size()) {
           // Fail this test with a fancy colored warning being printed.
           EXPECT_TRUE(false) << "Assembly code is not identical, but disassembly of machine code "
               "is equal: this implies sub-optimal encoding! Our code size=" << data->size() <<
               ", gcc size=" << res.code->size();
         } else {
           // Otherwise just print an info message and clean up.
           LOG(INFO) << "GCC chose a different encoding than ours, but the overall length is the "
               "same.";
           Clean(&res);
         }
       } else {
         // This will output the assembly.
         EXPECT_EQ(*data, *res.code) << "Outputs (and disassembly) not identical.";
       }
     }
   }

   // Structure to store intermediates and results.
   struct NativeAssemblerResult {
     bool ok;
     std::string error_msg;
     std::string base_name;
     std::unique_ptr<std::vector<uint8_t>> code;
     uintptr_t length;
   };

   // Compile the assembly file from_file to a binary file to_file. Returns true on success.
   bool Assemble(const char* from_file, const char* to_file, std::string* error_msg) {
     bool have_assembler = FileExists(GetAssemblerCommand());
     EXPECT_TRUE(have_assembler) << "Cannot find assembler:" << GetAssemblerCommand();
     if (!have_assembler) {
       return false;
     }

     std::vector<std::string> args;

     args.push_back(GetAssemblerCommand());
     args.push_back("-o");
     args.push_back(to_file);
     args.push_back(from_file);

     return Exec(args, error_msg);
   }

   // Runs objdump -h on the binary file and extracts the first line with .text.
   // Returns "" on failure.
   std::string Objdump(std::string file) {
     bool have_objdump = FileExists(GetObjdumpCommand());
     EXPECT_TRUE(have_objdump) << "Cannot find objdump: " << GetObjdumpCommand();
     if (!have_objdump) {
       return "";
     }

     std::string error_msg;
     std::vector<std::string> args;

     args.push_back(GetObjdumpCommand());
     args.push_back(file);
     args.push_back(">");
     args.push_back(file+".dump");
     std::string cmd = Join(args, ' ');

     args.clear();
     args.push_back("/bin/sh");
     args.push_back("-c");
     args.push_back(cmd);

     if (!Exec(args, &error_msg)) {
       EXPECT_TRUE(false) << error_msg;
     }

     std::ifstream dump(file+".dump");

     std::string line;
     bool found = false;
     while (std::getline(dump, line)) {
       if (line.find(".text") != line.npos) {
         found = true;
         break;
       }
     }

     dump.close();

     if (found) {
       return line;
     } else {
       return "";
     }
   }

   // Disassemble both binaries and compare the text.
   bool DisassembleBinaries(std::vector<uint8_t>& data, std::vector<uint8_t>& as,
                            std::string test_name) {
     std::string disassembler = GetDisassembleCommand();
     if (disassembler.length() == 0) {
       LOG(WARNING) << "No dissassembler command.";
       return false;
     }

     std::string data_name = WriteToFile(data, test_name + ".ass");
     std::string error_msg;
     if (!DisassembleBinary(data_name, &error_msg)) {
       LOG(INFO) << "Error disassembling: " << error_msg;
       std::remove(data_name.c_str());
       return false;
     }

     std::string as_name = WriteToFile(as, test_name + ".gcc");
     if (!DisassembleBinary(as_name, &error_msg)) {
       LOG(INFO) << "Error disassembling: " << error_msg;
       std::remove(data_name.c_str());
       std::remove((data_name + ".dis").c_str());
       std::remove(as_name.c_str());
       return false;
     }

     bool result = CompareFiles(data_name + ".dis", as_name + ".dis");

     if (result) {
       std::remove(data_name.c_str());
       std::remove(as_name.c_str());
       std::remove((data_name + ".dis").c_str());
       std::remove((as_name + ".dis").c_str());
     }

     return result;
   }

   bool DisassembleBinary(std::string file, std::string* error_msg) {
     std::vector<std::string> args;

     args.push_back(GetDisassembleCommand());
     args.push_back(file);
     args.push_back("| sed -n \'/<.data>/,$p\' | sed -e \'s/.*://\'");
     args.push_back(">");
     args.push_back(file+".dis");
     std::string cmd = Join(args, ' ');

     args.clear();
     args.push_back("/bin/sh");
     args.push_back("-c");
     args.push_back(cmd);

     return Exec(args, error_msg);
   }

   std::string WriteToFile(std::vector<uint8_t>& buffer, std::string test_name) {
     std::string file_name = GetTmpnam() + std::string("---") + test_name;
     const char* data = reinterpret_cast<char*>(buffer.data());
     std::ofstream s_out(file_name + ".o");
     s_out.write(data, buffer.size());
     s_out.close();
     return file_name + ".o";
   }

   bool CompareFiles(std::string f1, std::string f2) {
     std::ifstream f1_in(f1);
     std::ifstream f2_in(f2);

     bool result = std::equal(std::istreambuf_iterator<char>(f1_in),
                              std::istreambuf_iterator<char>(),
                              std::istreambuf_iterator<char>(f2_in));

     f1_in.close();
     f2_in.close();

     return result;
   }

   // Compile the given assembly code and extract the binary, if possible. Put result into res.
   bool Compile(std::string assembly_code, NativeAssemblerResult* res, std::string test_name) {
     res->ok = false;
     res->code.reset(nullptr);

     res->base_name = GetTmpnam() + std::string("---") + test_name;

     // TODO: Lots of error checking.

     std::ofstream s_out(res->base_name + ".S");
     s_out << assembly_code;
     s_out.close();

     if (!Assemble((res->base_name + ".S").c_str(), (res->base_name + ".o").c_str(),
                   &res->error_msg)) {
       res->error_msg = "Could not compile.";
       return false;
     }

     std::string odump = Objdump(res->base_name + ".o");
     if (odump.length() == 0) {
       res->error_msg = "Objdump failed.";
       return false;
     }

     std::istringstream iss(odump);
     std::istream_iterator<std::string> start(iss);
     std::istream_iterator<std::string> end;
     std::vector<std::string> tokens(start, end);

     if (tokens.size() < OBJDUMP_SECTION_LINE_MIN_TOKENS) {
       res->error_msg = "Objdump output not recognized: too few tokens.";
       return false;
     }

     if (tokens[1] != ".text") {
       res->error_msg = "Objdump output not recognized: .text not second token.";
       return false;
     }

     std::string lengthToken = "0x" + tokens[2];
     std::istringstream(lengthToken) >> std::hex >> res->length;

     std::string offsetToken = "0x" + tokens[5];
     uintptr_t offset;
     std::istringstream(offsetToken) >> std::hex >> offset;

     std::ifstream obj(res->base_name + ".o");
     obj.seekg(offset);
     res->code.reset(new std::vector<uint8_t>(res->length));
     obj.read(reinterpret_cast<char*>(&(*res->code)[0]), res->length);
     obj.close();

     res->ok = true;
     return true;
   }

   // Remove temporary files.
   void Clean(const NativeAssemblerResult* res) {
     std::remove((res->base_name + ".S").c_str());
     std::remove((res->base_name + ".o").c_str());
     std::remove((res->base_name + ".o.dump").c_str());
   }

   // Check whether file exists. Is used for commands, so strips off any parameters: anything after
   // the first space. We skip to the last slash for this, so it should work with directories with
   // spaces.
   static bool FileExists(std::string file) {
     if (file.length() == 0) {
       return false;
     }

     // Need to strip any options.
     size_t last_slash = file.find_last_of('/');
     if (last_slash == std::string::npos) {
       // No slash, start looking at the start.
       last_slash = 0;
     }
     size_t space_index = file.find(' ', last_slash);

     if (space_index == std::string::npos) {
       std::ifstream infile(file.c_str());
       return infile.good();
     } else {
       std::string copy = file.substr(0, space_index - 1);

       struct stat buf;
       return stat(copy.c_str(), &buf) == 0;
     }
   }

   static std::string GetGCCRootPath() {
     return "prebuilts/gcc/linux-x86";
   }

   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 FindTool(std::string tool_name) {
     // Find the current tool. Wild-card pattern is "arch-string*tool-name".
     std::string gcc_path = GetRootPath() + GetGCCRootPath();
     std::vector<std::string> args;
     args.push_back("find");
     args.push_back(gcc_path);
     args.push_back("-name");
     args.push_back(GetArchitectureString() + "*" + tool_name);
     args.push_back("|");
     args.push_back("sort");
     args.push_back("|");
     args.push_back("tail");
     args.push_back("-n");
     args.push_back("1");
     std::string tmp_file = GetTmpnam();
     args.push_back(">");
     args.push_back(tmp_file);
     std::string sh_args = Join(args, ' ');

     args.clear();
     args.push_back("/bin/sh");
     args.push_back("-c");
     args.push_back(sh_args);

     std::string error_msg;
     if (!Exec(args, &error_msg)) {
       EXPECT_TRUE(false) << error_msg;
       return "";
     }

     std::ifstream in(tmp_file.c_str());
     std::string line;
     if (!std::getline(in, line)) {
       in.close();
       std::remove(tmp_file.c_str());
       return "";
     }
     in.close();
     std::remove(tmp_file.c_str());
     return line;
   }

   // Use a consistent tmpnam, so store it.
   std::string GetTmpnam() {
     if (tmpnam_.length() == 0) {
       ScratchFile tmp;
       tmpnam_ = tmp.GetFilename() + "asm";
     }
     return tmpnam_;
   }

   std::unique_ptr<Ass> assembler_;

   std::string resolved_assembler_cmd_;
   std::string resolved_objdump_cmd_;
   std::string resolved_disassemble_cmd_;

   std::string android_data_;

   static constexpr size_t OBJDUMP_SECTION_LINE_MIN_TOKENS = 6;
 };

 }  // namespace art

 #endif  // ART_COMPILER_UTILS_ASSEMBLER_TEST_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_H_
	#define ART_COMPILER_UTILS_ASSEMBLER_TEST_H_

	#include "assembler.h"

	#include "common_runtime_test.h" // For ScratchFile

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

	namespace art {

	// Use a glocal static variable to keep the same name for all test data. Else we'll just spam the
	// temp directory.
	static std::string tmpnam_;

	template<typename Ass, typename Reg, typename Imm>
	class AssemblerTest : public testing::Test {
	public:
	Ass* GetAssembler() {
	return assembler_.get();
	}

	typedef std::string (TestFn)(Ass assembler);

	void DriverFn(TestFn f, std::string test_name) {
	Driver(f(assembler_.get()), test_name);
	}

	// This driver assumes the assembler has already been called.
	void DriverStr(std::string assembly_string, std::string test_name) {
	Driver(assembly_string, test_name);
	}

	std::string RepeatR(void (Ass::*f)(Reg), std::string fmt) {
	const std::vector<Reg*> registers = GetRegisters();
	std::string str;
	for (auto reg : registers) {
	(assembler_.get()->f)(reg);
	std::string base = fmt;

	size_t reg_index = base.find("{reg}");
	if (reg_index != std::string::npos) {
	std::ostringstream sreg;
	sreg << *reg;
	std::string reg_string = sreg.str();
	base.replace(reg_index, 5, reg_string);
	}

	if (str.size() > 0) {
	str += "\n";
	}
	str += base;
	}
	// Add a newline at the end.
	str += "\n";
	return str;
	}

	std::string RepeatRR(void (Ass::*f)(Reg, Reg), std::string fmt) {
	const std::vector<Reg*> registers = GetRegisters();
	std::string str;
	for (auto reg1 : registers) {
	for (auto reg2 : registers) {
	(assembler_.get()->f)(reg1, *reg2);
	std::string base = fmt;

	size_t reg1_index = base.find("{reg1}");
	if (reg1_index != std::string::npos) {
	std::ostringstream sreg;
	sreg << *reg1;
	std::string reg_string = sreg.str();
	base.replace(reg1_index, 6, reg_string);
	}

	size_t reg2_index = base.find("{reg2}");
	if (reg2_index != std::string::npos) {
	std::ostringstream sreg;
	sreg << *reg2;
	std::string reg_string = sreg.str();
	base.replace(reg2_index, 6, reg_string);
	}

	if (str.size() > 0) {
	str += "\n";
	}
	str += base;
	}
	}
	// Add a newline at the end.
	str += "\n";
	return str;
	}

	std::string RepeatRI(void (Ass::*f)(Reg, const Imm&), size_t imm_bytes, std::string fmt) {
	const std::vector<Reg*> registers = GetRegisters();
	std::string str;
	std::vector<int64_t> imms = CreateImmediateValues(imm_bytes);
	for (auto reg : registers) {
	for (int64_t imm : imms) {
	Imm* new_imm = CreateImmediate(imm);
	(assembler_.get()->f)(reg, *new_imm);
	delete new_imm;
	std::string base = fmt;

	size_t reg_index = base.find("{reg}");
	if (reg_index != std::string::npos) {
	std::ostringstream sreg;
	sreg << *reg;
	std::string reg_string = sreg.str();
	base.replace(reg_index, 5, reg_string);
	}

	size_t imm_index = base.find("{imm}");
	if (imm_index != std::string::npos) {
	std::ostringstream sreg;
	sreg << imm;
	std::string imm_string = sreg.str();
	base.replace(imm_index, 5, imm_string);
	}

	if (str.size() > 0) {
	str += "\n";
	}
	str += base;
	}
	}
	// Add a newline at the end.
	str += "\n";
	return str;
	}

	std::string RepeatI(void (Ass::*f)(const Imm&), size_t imm_bytes, std::string fmt) {
	std::string str;
	std::vector<int64_t> imms = CreateImmediateValues(imm_bytes);
	for (int64_t imm : imms) {
	Imm* new_imm = CreateImmediate(imm);
	(assembler_.get()->f)(new_imm);
	delete new_imm;
	std::string base = fmt;

	size_t imm_index = base.find("{imm}");
	if (imm_index != std::string::npos) {
	std::ostringstream sreg;
	sreg << imm;
	std::string imm_string = sreg.str();
	base.replace(imm_index, 5, imm_string);
	}

	if (str.size() > 0) {
	str += "\n";
	}
	str += base;
	}
	// Add a newline at the end.
	str += "\n";
	return str;
	}

	// This is intended to be run as a test.
	bool CheckTools() {
	if (!FileExists(GetAssemblerCommand())) {
	return false;
	}
	LOG(INFO) << "Chosen assembler command: " << GetAssemblerCommand();

	if (!FileExists(GetObjdumpCommand())) {
	return false;
	}
	LOG(INFO) << "Chosen objdump command: " << GetObjdumpCommand();

	// Disassembly is optional.
	std::string disassembler = GetDisassembleCommand();
	if (disassembler.length() != 0) {
	if (!FileExists(disassembler)) {
	return false;
	}
	LOG(INFO) << "Chosen disassemble command: " << GetDisassembleCommand();
	} else {
	LOG(INFO) << "No disassembler given.";
	}

	return true;
	}

	protected:
	void SetUp() OVERRIDE {
	assembler_.reset(new Ass());

	// Fake a runtime test for ScratchFile
	CommonRuntimeTest::SetUpAndroidData(android_data_);

	SetUpHelpers();
	}

	void TearDown() OVERRIDE {
	// We leave temporaries in case this failed so we can debug issues.
	CommonRuntimeTest::TearDownAndroidData(android_data_, false);
	tmpnam_ = "";
	}

	// Override this to set up any architecture-specific things, e.g., register vectors.
	virtual void SetUpHelpers() {}

	virtual std::vector<Reg*> GetRegisters() = 0;

	// Get the typically used name for this architecture, e.g., aarch64, x86_64, ...
	virtual std::string GetArchitectureString() = 0;

	// Get the name of the assembler, e.g., "as" by default.
	virtual std::string GetAssemblerCmdName() {
	return "as";
	}

	// Switches to the assembler command. Default none.
	virtual std::string GetAssemblerParameters() {
	return "";
	}

	// Return the host assembler command for this test.
	virtual std::string GetAssemblerCommand() {
	// Already resolved it once?
	if (resolved_assembler_cmd_.length() != 0) {
	return resolved_assembler_cmd_;
	}

	std::string line = FindTool(GetAssemblerCmdName());
	if (line.length() == 0) {
	return line;
	}

	resolved_assembler_cmd_ = line + GetAssemblerParameters();

	return line;
	}

	// Get the name of the objdump, e.g., "objdump" by default.
	virtual std::string GetObjdumpCmdName() {
	return "objdump";
	}

	// Switches to the objdump command. Default is " -h".
	virtual std::string GetObjdumpParameters() {
	return " -h";
	}

	// Return the host objdump command for this test.
	virtual std::string GetObjdumpCommand() {
	// Already resolved it once?
	if (resolved_objdump_cmd_.length() != 0) {
	return resolved_objdump_cmd_;
	}

	std::string line = FindTool(GetObjdumpCmdName());
	if (line.length() == 0) {
	return line;
	}

	resolved_objdump_cmd_ = line + GetObjdumpParameters();

	return line;
	}

	// Get the name of the objdump, e.g., "objdump" by default.
	virtual std::string GetDisassembleCmdName() {
	return "objdump";
	}

	// Switches to the objdump command. As it's a binary, one needs to push the architecture and
	// such to objdump, so it's architecture-specific and there is no default.
	virtual std::string GetDisassembleParameters() = 0;

	// Return the host disassembler command for this test.
	virtual std::string GetDisassembleCommand() {
	// Already resolved it once?
	if (resolved_disassemble_cmd_.length() != 0) {
	return resolved_disassemble_cmd_;
	}

	std::string line = FindTool(GetDisassembleCmdName());
	if (line.length() == 0) {
	return line;
	}

	resolved_disassemble_cmd_ = line + GetDisassembleParameters();

	return line;
	}

	// Create a couple of immediate values up to the number of bytes given.
	virtual std::vector<int64_t> CreateImmediateValues(size_t imm_bytes) {
	std::vector<int64_t> res;
	res.push_back(0);
	res.push_back(-1);
	res.push_back(0x12);
	if (imm_bytes >= 2) {
	res.push_back(0x1234);
	res.push_back(-0x1234);
	if (imm_bytes >= 4) {
	res.push_back(0x12345678);
	res.push_back(-0x12345678);
	if (imm_bytes >= 6) {
	res.push_back(0x123456789ABC);
	res.push_back(-0x123456789ABC);
	if (imm_bytes >= 8) {
	res.push_back(0x123456789ABCDEF0);
	res.push_back(-0x123456789ABCDEF0);
	}
	}
	}
	}
	return res;
	}

	// Create an immediate from the specific value.
	virtual Imm* CreateImmediate(int64_t imm_value) = 0;

	private:
	// 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(std::string assembly_text, std::string test_name) {
	EXPECT_NE(assembly_text.length(), 0U) << "Empty assembly";

	NativeAssemblerResult res;
	Compile(assembly_text, &res, test_name);

	EXPECT_TRUE(res.ok) << res.error_msg;
	if (!res.ok) {
	// No way of continuing.
	return;
	}

	size_t cs = assembler_->CodeSize();
	std::unique_ptr<std::vector<uint8_t>> data(new std::vector<uint8_t>(cs));
	MemoryRegion code(&(*data)[0], data->size());
	assembler_->FinalizeInstructions(code);

	if (data == res.code) {
	Clean(&res);
	} else {
	if (DisassembleBinaries(data, res.code, test_name)) {
	if (data->size() > res.code->size()) {
	// Fail this test with a fancy colored warning being printed.
	EXPECT_TRUE(false) << "Assembly code is not identical, but disassembly of machine code "
	"is equal: this implies sub-optimal encoding! Our code size=" << data->size() <<
	", gcc size=" << res.code->size();
	} else {
	// Otherwise just print an info message and clean up.
	LOG(INFO) << "GCC chose a different encoding than ours, but the overall length is the "
	"same.";
	Clean(&res);
	}
	} else {
	// This will output the assembly.
	EXPECT_EQ(data, res.code) << "Outputs (and disassembly) not identical.";
	}
	}
	}

	// Structure to store intermediates and results.
	struct NativeAssemblerResult {
	bool ok;
	std::string error_msg;
	std::string base_name;
	std::unique_ptr<std::vector<uint8_t>> code;
	uintptr_t length;
	};

	// Compile the assembly file from_file to a binary file to_file. Returns true on success.
	bool Assemble(const char* from_file, const char* to_file, std::string* error_msg) {
	bool have_assembler = FileExists(GetAssemblerCommand());
	EXPECT_TRUE(have_assembler) << "Cannot find assembler:" << GetAssemblerCommand();
	if (!have_assembler) {
	return false;
	}

	std::vector<std::string> args;

	args.push_back(GetAssemblerCommand());
	args.push_back("-o");
	args.push_back(to_file);
	args.push_back(from_file);

	return Exec(args, error_msg);
	}

	// Runs objdump -h on the binary file and extracts the first line with .text.
	// Returns "" on failure.
	std::string Objdump(std::string file) {
	bool have_objdump = FileExists(GetObjdumpCommand());
	EXPECT_TRUE(have_objdump) << "Cannot find objdump: " << GetObjdumpCommand();
	if (!have_objdump) {
	return "";
	}

	std::string error_msg;
	std::vector<std::string> args;

	args.push_back(GetObjdumpCommand());
	args.push_back(file);
	args.push_back(">");
	args.push_back(file+".dump");
	std::string cmd = Join(args, ' ');

	args.clear();
	args.push_back("/bin/sh");
	args.push_back("-c");
	args.push_back(cmd);

	if (!Exec(args, &error_msg)) {
	EXPECT_TRUE(false) << error_msg;
	}

	std::ifstream dump(file+".dump");

	std::string line;
	bool found = false;
	while (std::getline(dump, line)) {
	if (line.find(".text") != line.npos) {
	found = true;
	break;
	}
	}

	dump.close();

	if (found) {
	return line;
	} else {
	return "";
	}
	}

	// Disassemble both binaries and compare the text.
	bool DisassembleBinaries(std::vector<uint8_t>& data, std::vector<uint8_t>& as,
	std::string test_name) {
	std::string disassembler = GetDisassembleCommand();
	if (disassembler.length() == 0) {
	LOG(WARNING) << "No dissassembler command.";
	return false;
	}

	std::string data_name = WriteToFile(data, test_name + ".ass");
	std::string error_msg;
	if (!DisassembleBinary(data_name, &error_msg)) {
	LOG(INFO) << "Error disassembling: " << error_msg;
	std::remove(data_name.c_str());
	return false;
	}

	std::string as_name = WriteToFile(as, test_name + ".gcc");
	if (!DisassembleBinary(as_name, &error_msg)) {
	LOG(INFO) << "Error disassembling: " << error_msg;
	std::remove(data_name.c_str());
	std::remove((data_name + ".dis").c_str());
	std::remove(as_name.c_str());
	return false;
	}

	bool result = CompareFiles(data_name + ".dis", as_name + ".dis");

	if (result) {
	std::remove(data_name.c_str());
	std::remove(as_name.c_str());
	std::remove((data_name + ".dis").c_str());
	std::remove((as_name + ".dis").c_str());
	}

	return result;
	}

	bool DisassembleBinary(std::string file, std::string* error_msg) {
	std::vector<std::string> args;

	args.push_back(GetDisassembleCommand());
	args.push_back(file);
	args.push_back("\| sed -n \'/<.data>/,$p\' \| sed -e \'s/.*://\'");
	args.push_back(">");
	args.push_back(file+".dis");
	std::string cmd = Join(args, ' ');

	args.clear();
	args.push_back("/bin/sh");
	args.push_back("-c");
	args.push_back(cmd);

	return Exec(args, error_msg);
	}

	std::string WriteToFile(std::vector<uint8_t>& buffer, std::string test_name) {
	std::string file_name = GetTmpnam() + std::string("---") + test_name;
	const char* data = reinterpret_cast<char*>(buffer.data());
	std::ofstream s_out(file_name + ".o");
	s_out.write(data, buffer.size());
	s_out.close();
	return file_name + ".o";
	}

	bool CompareFiles(std::string f1, std::string f2) {
	std::ifstream f1_in(f1);
	std::ifstream f2_in(f2);

	bool result = std::equal(std::istreambuf_iterator<char>(f1_in),
	std::istreambuf_iterator<char>(),
	std::istreambuf_iterator<char>(f2_in));

	f1_in.close();
	f2_in.close();

	return result;
	}

	// Compile the given assembly code and extract the binary, if possible. Put result into res.
	bool Compile(std::string assembly_code, NativeAssemblerResult* res, std::string test_name) {
	res->ok = false;
	res->code.reset(nullptr);

	res->base_name = GetTmpnam() + std::string("---") + test_name;

	// TODO: Lots of error checking.

	std::ofstream s_out(res->base_name + ".S");
	s_out << assembly_code;
	s_out.close();

	if (!Assemble((res->base_name + ".S").c_str(), (res->base_name + ".o").c_str(),
	&res->error_msg)) {
	res->error_msg = "Could not compile.";
	return false;
	}

	std::string odump = Objdump(res->base_name + ".o");
	if (odump.length() == 0) {
	res->error_msg = "Objdump failed.";
	return false;
	}

	std::istringstream iss(odump);
	std::istream_iterator<std::string> start(iss);
	std::istream_iterator<std::string> end;
	std::vector<std::string> tokens(start, end);

	if (tokens.size() < OBJDUMP_SECTION_LINE_MIN_TOKENS) {
	res->error_msg = "Objdump output not recognized: too few tokens.";
	return false;
	}

	if (tokens[1] != ".text") {
	res->error_msg = "Objdump output not recognized: .text not second token.";
	return false;
	}

	std::string lengthToken = "0x" + tokens[2];
	std::istringstream(lengthToken) >> std::hex >> res->length;

	std::string offsetToken = "0x" + tokens[5];
	uintptr_t offset;
	std::istringstream(offsetToken) >> std::hex >> offset;

	std::ifstream obj(res->base_name + ".o");
	obj.seekg(offset);
	res->code.reset(new std::vector<uint8_t>(res->length));
	obj.read(reinterpret_cast<char>(&(res->code)[0]), res->length);
	obj.close();

	res->ok = true;
	return true;
	}

	// Remove temporary files.
	void Clean(const NativeAssemblerResult* res) {
	std::remove((res->base_name + ".S").c_str());
	std::remove((res->base_name + ".o").c_str());
	std::remove((res->base_name + ".o.dump").c_str());
	}

	// Check whether file exists. Is used for commands, so strips off any parameters: anything after
	// the first space. We skip to the last slash for this, so it should work with directories with
	// spaces.
	static bool FileExists(std::string file) {
	if (file.length() == 0) {
	return false;
	}

	// Need to strip any options.
	size_t last_slash = file.find_last_of('/');
	if (last_slash == std::string::npos) {
	// No slash, start looking at the start.
	last_slash = 0;
	}
	size_t space_index = file.find(' ', last_slash);

	if (space_index == std::string::npos) {
	std::ifstream infile(file.c_str());
	return infile.good();
	} else {
	std::string copy = file.substr(0, space_index - 1);

	struct stat buf;
	return stat(copy.c_str(), &buf) == 0;
	}
	}

	static std::string GetGCCRootPath() {
	return "prebuilts/gcc/linux-x86";
	}

	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 FindTool(std::string tool_name) {
	// Find the current tool. Wild-card pattern is "arch-string*tool-name".
	std::string gcc_path = GetRootPath() + GetGCCRootPath();
	std::vector<std::string> args;
	args.push_back("find");
	args.push_back(gcc_path);
	args.push_back("-name");
	args.push_back(GetArchitectureString() + "*" + tool_name);
	args.push_back("\|");
	args.push_back("sort");
	args.push_back("\|");
	args.push_back("tail");
	args.push_back("-n");
	args.push_back("1");
	std::string tmp_file = GetTmpnam();
	args.push_back(">");
	args.push_back(tmp_file);
	std::string sh_args = Join(args, ' ');

	args.clear();
	args.push_back("/bin/sh");
	args.push_back("-c");
	args.push_back(sh_args);

	std::string error_msg;
	if (!Exec(args, &error_msg)) {
	EXPECT_TRUE(false) << error_msg;
	return "";
	}

	std::ifstream in(tmp_file.c_str());
	std::string line;
	if (!std::getline(in, line)) {
	in.close();
	std::remove(tmp_file.c_str());
	return "";
	}
	in.close();
	std::remove(tmp_file.c_str());
	return line;
	}

	// Use a consistent tmpnam, so store it.
	std::string GetTmpnam() {
	if (tmpnam_.length() == 0) {
	ScratchFile tmp;
	tmpnam_ = tmp.GetFilename() + "asm";
	}
	return tmpnam_;
	}

	std::unique_ptr<Ass> assembler_;

	std::string resolved_assembler_cmd_;
	std::string resolved_objdump_cmd_;
	std::string resolved_disassemble_cmd_;

	std::string android_data_;

	static constexpr size_t OBJDUMP_SECTION_LINE_MIN_TOKENS = 6;
	};

	} // namespace art

	#endif // ART_COMPILER_UTILS_ASSEMBLER_TEST_H_