tools/aapt2/cmd/Command.cpp - platform/frameworks/base - Git at Google

 /*
  * Copyright (C) 2018 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.
  */

 #include "Command.h"

 #include <iomanip>
 #include <iostream>
 #include <string>
 #include <vector>

 #include "android-base/stringprintf.h"
 #include "android-base/utf8.h"
 #include "androidfw/StringPiece.h"

 #include "trace/TraceBuffer.h"
 #include "util/Util.h"

 using android::base::StringPrintf;
 using android::StringPiece;

 namespace aapt {

 std::string GetSafePath(StringPiece arg) {
 #ifdef _WIN32
   // If the path exceeds the maximum path length for Windows, encode the path using the
   // extended-length prefix
   std::wstring path16;
   CHECK(android::base::UTF8PathToWindowsLongPath(arg.data(), &path16))
       << "Failed to convert file path to UTF-16: file path " << arg.data();

   std::string path8;
   CHECK(android::base::WideToUTF8(path16, &path8))
       << "Failed to convert file path back to UTF-8: file path " << arg.data();

   return path8;
 #else
   return std::string(arg);
 #endif
 }

 void Command::AddRequiredFlag(StringPiece name, StringPiece description, std::string* value,
                               uint32_t flags) {
   auto func = [value, flags](StringPiece arg, std::ostream*) -> bool {
     *value = (flags & Command::kPath) ? GetSafePath(arg) : std::string(arg);
     return true;
   };

   flags_.emplace_back(
       Flag(name, description, /* required */ true, /* num_args */ 1, std::move(func)));
 }

 void Command::AddRequiredFlagList(StringPiece name, StringPiece description,
                                   std::vector<std::string>* value, uint32_t flags) {
   auto func = [value, flags](StringPiece arg, std::ostream*) -> bool {
     value->push_back((flags & Command::kPath) ? GetSafePath(arg) : std::string(arg));
     return true;
   };

   flags_.emplace_back(
       Flag(name, description, /* required */ true, /* num_args */ 1, std::move(func)));
 }

 void Command::AddOptionalFlag(StringPiece name, StringPiece description,
                               std::optional<std::string>* value, uint32_t flags) {
   auto func = [value, flags](StringPiece arg, std::ostream*) -> bool {
     *value = (flags & Command::kPath) ? GetSafePath(arg) : std::string(arg);
     return true;
   };

   flags_.emplace_back(
       Flag(name, description, /* required */ false, /* num_args */ 1, std::move(func)));
 }

 void Command::AddOptionalFlagList(StringPiece name, StringPiece description,
                                   std::vector<std::string>* value, uint32_t flags) {
   auto func = [value, flags](StringPiece arg, std::ostream*) -> bool {
     value->push_back((flags & Command::kPath) ? GetSafePath(arg) : std::string(arg));
     return true;
   };

   flags_.emplace_back(
       Flag(name, description, /* required */ false, /* num_args */ 1, std::move(func)));
 }

 void Command::AddOptionalFlagList(StringPiece name, StringPiece description,
                                   std::unordered_set<std::string>* value) {
   auto func = [value](StringPiece arg, std::ostream* out_error) -> bool {
     value->emplace(arg);
     return true;
   };

   flags_.emplace_back(
       Flag(name, description, /* required */ false, /* num_args */ 1, std::move(func)));
 }

 void Command::AddOptionalSwitch(StringPiece name, StringPiece description, bool* value) {
   auto func = [value](StringPiece arg, std::ostream* out_error) -> bool {
     *value = true;
     return true;
   };

   flags_.emplace_back(
       Flag(name, description, /* required */ false, /* num_args */ 0, std::move(func)));
 }

 void Command::AddOptionalSubcommand(std::unique_ptr<Command>&& subcommand, bool experimental) {
   subcommand->full_subcommand_name_ = StringPrintf("%s %s", name_.data(), subcommand->name_.data());
   if (experimental) {
     experimental_subcommands_.push_back(std::move(subcommand));
   } else {
     subcommands_.push_back(std::move(subcommand));
   }
 }

 void Command::SetDescription(StringPiece description) {
   description_ = std::string(description);
 }

 void Command::Usage(std::ostream* out) {
   constexpr size_t kWidth = 50;

   *out << full_subcommand_name_;

   if (!subcommands_.empty()) {
     *out << " [subcommand]";
   }

   *out << " [options]";
   for (const Flag& flag : flags_) {
     if (flag.is_required) {
       *out << " " << flag.name << " arg";
     }
   }

   *out << " files...\n";

   if (!subcommands_.empty()) {
     *out << "\nSubcommands:\n";
     for (auto& subcommand : subcommands_) {
       std::string argline = subcommand->name_;

       // Split the description by newlines and write out the argument (which is
       // empty after the first line) followed by the description line. This will make sure
       // that multiline descriptions are still right justified and aligned.
       for (StringPiece line : util::Tokenize(subcommand->description_, '\n')) {
         *out << " " << std::setw(kWidth) << std::left << argline << line << "\n";
         argline = " ";
       }
     }
   }

   *out << "\nOptions:\n";

   for (const Flag& flag : flags_) {
     std::string argline = flag.name;
     if (flag.num_args > 0) {
       argline += " arg";
     }

     // Split the description by newlines and write out the argument (which is
     // empty after the first line) followed by the description line. This will make sure
     // that multiline descriptions are still right justified and aligned.
     for (StringPiece line : util::Tokenize(flag.description, '\n')) {
       *out << " " << std::setw(kWidth) << std::left << argline << line << "\n";
       argline = " ";
     }
   }
   out->flush();
 }

 const std::string& Command::addEnvironmentArg(const Flag& flag, const char* env) {
   if (*env && flag.num_args > 0) {
     return environment_args_.emplace_back(flag.name + '=' + env);
   }
   return flag.name;
 }

 //
 // Looks for the flags specified in the environment and adds them to |args|.
 // Expected format:
 // - _AAPT2_UPPERCASE_NAME are added before all of the command line flags, so it's
 //   a default for the flag that may get overridden by the command line.
 // - AAPT2_UPPERCASE_NAME_ are added after them, making this to be the final value
 //   even if there was something on the command line.
 // - All dashes in the flag name get replaced with underscores, the rest of it is
 //   intact.
 //
 // E.g.
 //  --set-some-flag becomes either _AAPT2_SET_SOME_FLAG or AAPT2_SET_SOME_FLAG_
 //  --set-param=2 is _AAPT2_SET_SOME_FLAG=2
 //
 // Values get passed as it, with no processing or quoting.
 //
 // This way one can make sure aapt2 has the flags they need even when it is
 // launched in a way they can't control, e.g. deep inside a build.
 //
 void Command::parseFlagsFromEnvironment(std::vector<StringPiece>& args) {
   // If the first argument is a subcommand then skip it and prepend the flags past that (the root
   // command should only have a single '-h' flag anyway).
   const int insert_pos = args.empty() ? 0 : args.front().starts_with('-') ? 0 : 1;

   std::string env_name;
   for (const Flag& flag : flags_) {
     // First, the prefix version.
     env_name.assign("_AAPT2_");
     // Append the uppercased flag name, skipping all dashes in front and replacing them with
     // underscores later.
     auto name_start = flag.name.begin();
     while (name_start != flag.name.end() && *name_start == '-') {
       ++name_start;
     }
     std::transform(name_start, flag.name.end(), std::back_inserter(env_name),
                    [](char c) { return c == '-' ? '_' : toupper(c); });
     if (auto prefix_env = getenv(env_name.c_str())) {
       args.insert(args.begin() + insert_pos, addEnvironmentArg(flag, prefix_env));
     }
     // Now reuse the same name variable to construct a suffix version: append the
     // underscore and just skip the one in front.
     env_name += '_';
     if (auto suffix_env = getenv(env_name.c_str() + 1)) {
       args.push_back(addEnvironmentArg(flag, suffix_env));
     }
   }
 }

 int Command::Execute(std::vector<StringPiece>& args, std::ostream* out_error) {
   TRACE_NAME_ARGS("Command::Execute", args);
   std::vector<std::string> file_args;

   parseFlagsFromEnvironment(args);

   for (size_t i = 0; i < args.size(); i++) {
     StringPiece arg = args[i];
     if (*(arg.data()) != '-') {
       // Continue parsing as a subcommand if the first argument matches one of the subcommands
       if (i == 0) {
         for (auto& subcommand : subcommands_) {
           if (arg == subcommand->name_ || (!subcommand->short_name_.empty()
                                            && arg == subcommand->short_name_)) {
             return subcommand->Execute(
                 std::vector<StringPiece>(args.begin() + 1, args.end()), out_error);
           }
         }
         for (auto& subcommand : experimental_subcommands_) {
           if (arg == subcommand->name_ || (!subcommand->short_name_.empty()
                                            && arg == subcommand->short_name_)) {
             return subcommand->Execute(
               std::vector<StringPiece>(args.begin() + 1, args.end()), out_error);
           }
         }
       }

       file_args.push_back(GetSafePath(arg));
       continue;
     }

     if (arg == "-h" || arg == "--help") {
       Usage(out_error);
       return 1;
     }

     static constexpr auto matchShortArg = [](std::string_view arg, const Flag& flag) static {
       return flag.name.starts_with("--") &&
              arg.compare(0, 2, std::string_view(flag.name.c_str() + 1, 2)) == 0;
     };

     bool match = false;
     for (Flag& flag : flags_) {
       // Allow both "--arg value" and "--arg=value" syntax, and look for the cases where we can
       // safely deduce the "--arg" flag from the short "-a" version when there's no value expected
       bool matched_current = false;
       if (arg.starts_with(flag.name) &&
           (arg.size() == flag.name.size() || (flag.num_args > 0 && arg[flag.name.size()] == '='))) {
         matched_current = true;
       } else if (flag.num_args == 0 && matchShortArg(arg, flag)) {
         matched_current = true;
         // It matches, now need to make sure no other flag would match as well.
         // This is really inefficient, but we don't expect to have enough flags for it to matter
         // (famous last words).
         for (const Flag& other_flag : flags_) {
           if (&other_flag == &flag) {
             continue;
           }
           if (matchShortArg(arg, other_flag)) {
             matched_current = false;  // ambiguous, skip this match
             break;
           }
         }
       }
       if (!matched_current) {
         continue;
       }

       if (flag.num_args > 0) {
         if (arg.size() == flag.name.size()) {
           i++;
           if (i >= args.size()) {
             *out_error << flag.name << " missing argument.\n\n";
             Usage(out_error);
             return 1;
           }
           arg = args[i];
         } else {
           arg.remove_prefix(flag.name.size() + 1);
           // Disallow empty arguments after '='.
           if (arg.empty()) {
             *out_error << flag.name << " has empty argument.\n\n";
             Usage(out_error);
             return 1;
           }
         }
         if (!flag.action(arg, out_error)) {
           return 1;
         }
       } else {
         if (!flag.action({}, out_error)) {
           return 1;
         }
       }
       flag.found = true;
       match = true;
       break;
     }

     if (!match) {
       *out_error << "unknown option '" << arg << "'.\n\n";
       Usage(out_error);
       return 1;
     }
   }

   for (const Flag& flag : flags_) {
     if (flag.is_required && !flag.found) {
       *out_error << "missing required flag " << flag.name << "\n\n";
       Usage(out_error);
       return 1;
     }
   }

   return Action(file_args);
 }

 }  // namespace aapt
	/*
	* Copyright (C) 2018 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.
	*/

	#include "Command.h"

	#include <iomanip>
	#include <iostream>
	#include <string>
	#include <vector>

	#include "android-base/stringprintf.h"
	#include "android-base/utf8.h"
	#include "androidfw/StringPiece.h"

	#include "trace/TraceBuffer.h"
	#include "util/Util.h"

	using android::base::StringPrintf;
	using android::StringPiece;

	namespace aapt {

	std::string GetSafePath(StringPiece arg) {
	#ifdef _WIN32
	// If the path exceeds the maximum path length for Windows, encode the path using the
	// extended-length prefix
	std::wstring path16;
	CHECK(android::base::UTF8PathToWindowsLongPath(arg.data(), &path16))
	<< "Failed to convert file path to UTF-16: file path " << arg.data();

	std::string path8;
	CHECK(android::base::WideToUTF8(path16, &path8))
	<< "Failed to convert file path back to UTF-8: file path " << arg.data();

	return path8;
	#else
	return std::string(arg);
	#endif
	}

	void Command::AddRequiredFlag(StringPiece name, StringPiece description, std::string* value,
	uint32_t flags) {
	auto func = [value, flags](StringPiece arg, std::ostream*) -> bool {
	*value = (flags & Command::kPath) ? GetSafePath(arg) : std::string(arg);
	return true;
	};

	flags_.emplace_back(
	Flag(name, description, /* required / true, / num_args */ 1, std::move(func)));
	}

	void Command::AddRequiredFlagList(StringPiece name, StringPiece description,
	std::vector<std::string>* value, uint32_t flags) {
	auto func = [value, flags](StringPiece arg, std::ostream*) -> bool {
	value->push_back((flags & Command::kPath) ? GetSafePath(arg) : std::string(arg));
	return true;
	};

	flags_.emplace_back(
	Flag(name, description, /* required / true, / num_args */ 1, std::move(func)));
	}

	void Command::AddOptionalFlag(StringPiece name, StringPiece description,
	std::optional<std::string>* value, uint32_t flags) {
	auto func = [value, flags](StringPiece arg, std::ostream*) -> bool {
	*value = (flags & Command::kPath) ? GetSafePath(arg) : std::string(arg);
	return true;
	};

	flags_.emplace_back(
	Flag(name, description, /* required / false, / num_args */ 1, std::move(func)));
	}

	void Command::AddOptionalFlagList(StringPiece name, StringPiece description,
	std::vector<std::string>* value, uint32_t flags) {
	auto func = [value, flags](StringPiece arg, std::ostream*) -> bool {
	value->push_back((flags & Command::kPath) ? GetSafePath(arg) : std::string(arg));
	return true;
	};

	flags_.emplace_back(
	Flag(name, description, /* required / false, / num_args */ 1, std::move(func)));
	}

	void Command::AddOptionalFlagList(StringPiece name, StringPiece description,
	std::unordered_set<std::string>* value) {
	auto func = [value](StringPiece arg, std::ostream* out_error) -> bool {
	value->emplace(arg);
	return true;
	};

	flags_.emplace_back(
	Flag(name, description, /* required / false, / num_args */ 1, std::move(func)));
	}

	void Command::AddOptionalSwitch(StringPiece name, StringPiece description, bool* value) {
	auto func = [value](StringPiece arg, std::ostream* out_error) -> bool {
	*value = true;
	return true;
	};

	flags_.emplace_back(
	Flag(name, description, /* required / false, / num_args */ 0, std::move(func)));
	}

	void Command::AddOptionalSubcommand(std::unique_ptr<Command>&& subcommand, bool experimental) {
	subcommand->full_subcommand_name_ = StringPrintf("%s %s", name_.data(), subcommand->name_.data());
	if (experimental) {
	experimental_subcommands_.push_back(std::move(subcommand));
	} else {
	subcommands_.push_back(std::move(subcommand));
	}
	}

	void Command::SetDescription(StringPiece description) {
	description_ = std::string(description);
	}

	void Command::Usage(std::ostream* out) {
	constexpr size_t kWidth = 50;

	*out << full_subcommand_name_;

	if (!subcommands_.empty()) {
	*out << " [subcommand]";
	}

	*out << " [options]";
	for (const Flag& flag : flags_) {
	if (flag.is_required) {
	*out << " " << flag.name << " arg";
	}
	}

	*out << " files...\n";

	if (!subcommands_.empty()) {
	*out << "\nSubcommands:\n";
	for (auto& subcommand : subcommands_) {
	std::string argline = subcommand->name_;

	// Split the description by newlines and write out the argument (which is
	// empty after the first line) followed by the description line. This will make sure
	// that multiline descriptions are still right justified and aligned.
	for (StringPiece line : util::Tokenize(subcommand->description_, '\n')) {
	*out << " " << std::setw(kWidth) << std::left << argline << line << "\n";
	argline = " ";
	}
	}
	}

	*out << "\nOptions:\n";

	for (const Flag& flag : flags_) {
	std::string argline = flag.name;
	if (flag.num_args > 0) {
	argline += " arg";
	}

	// Split the description by newlines and write out the argument (which is
	// empty after the first line) followed by the description line. This will make sure
	// that multiline descriptions are still right justified and aligned.
	for (StringPiece line : util::Tokenize(flag.description, '\n')) {
	*out << " " << std::setw(kWidth) << std::left << argline << line << "\n";
	argline = " ";
	}
	}
	out->flush();
	}

	const std::string& Command::addEnvironmentArg(const Flag& flag, const char* env) {
	if (*env && flag.num_args > 0) {
	return environment_args_.emplace_back(flag.name + '=' + env);
	}
	return flag.name;
	}

	//
	// Looks for the flags specified in the environment and adds them to \|args\|.
	// Expected format:
	// - _AAPT2_UPPERCASE_NAME are added before all of the command line flags, so it's
	// a default for the flag that may get overridden by the command line.
	// - AAPT2_UPPERCASE_NAME_ are added after them, making this to be the final value
	// even if there was something on the command line.
	// - All dashes in the flag name get replaced with underscores, the rest of it is
	// intact.
	//
	// E.g.
	// --set-some-flag becomes either _AAPT2_SET_SOME_FLAG or AAPT2_SET_SOME_FLAG_
	// --set-param=2 is _AAPT2_SET_SOME_FLAG=2
	//
	// Values get passed as it, with no processing or quoting.
	//
	// This way one can make sure aapt2 has the flags they need even when it is
	// launched in a way they can't control, e.g. deep inside a build.
	//
	void Command::parseFlagsFromEnvironment(std::vector<StringPiece>& args) {
	// If the first argument is a subcommand then skip it and prepend the flags past that (the root
	// command should only have a single '-h' flag anyway).
	const int insert_pos = args.empty() ? 0 : args.front().starts_with('-') ? 0 : 1;

	std::string env_name;
	for (const Flag& flag : flags_) {
	// First, the prefix version.
	env_name.assign("_AAPT2_");
	// Append the uppercased flag name, skipping all dashes in front and replacing them with
	// underscores later.
	auto name_start = flag.name.begin();
	while (name_start != flag.name.end() && *name_start == '-') {
	++name_start;
	}
	std::transform(name_start, flag.name.end(), std::back_inserter(env_name),
	[](char c) { return c == '-' ? '_' : toupper(c); });
	if (auto prefix_env = getenv(env_name.c_str())) {
	args.insert(args.begin() + insert_pos, addEnvironmentArg(flag, prefix_env));
	}
	// Now reuse the same name variable to construct a suffix version: append the
	// underscore and just skip the one in front.
	env_name += '_';
	if (auto suffix_env = getenv(env_name.c_str() + 1)) {
	args.push_back(addEnvironmentArg(flag, suffix_env));
	}
	}
	}

	int Command::Execute(std::vector<StringPiece>& args, std::ostream* out_error) {
	TRACE_NAME_ARGS("Command::Execute", args);
	std::vector<std::string> file_args;

	parseFlagsFromEnvironment(args);

	for (size_t i = 0; i < args.size(); i++) {
	StringPiece arg = args[i];
	if (*(arg.data()) != '-') {
	// Continue parsing as a subcommand if the first argument matches one of the subcommands
	if (i == 0) {
	for (auto& subcommand : subcommands_) {
	if (arg == subcommand->name_ \|\| (!subcommand->short_name_.empty()
	&& arg == subcommand->short_name_)) {
	return subcommand->Execute(
	std::vector<StringPiece>(args.begin() + 1, args.end()), out_error);
	}
	}
	for (auto& subcommand : experimental_subcommands_) {
	if (arg == subcommand->name_ \|\| (!subcommand->short_name_.empty()
	&& arg == subcommand->short_name_)) {
	return subcommand->Execute(
	std::vector<StringPiece>(args.begin() + 1, args.end()), out_error);
	}
	}
	}

	file_args.push_back(GetSafePath(arg));
	continue;
	}

	if (arg == "-h" \|\| arg == "--help") {
	Usage(out_error);
	return 1;
	}

	static constexpr auto matchShortArg = [](std::string_view arg, const Flag& flag) static {
	return flag.name.starts_with("--") &&
	arg.compare(0, 2, std::string_view(flag.name.c_str() + 1, 2)) == 0;
	};

	bool match = false;
	for (Flag& flag : flags_) {
	// Allow both "--arg value" and "--arg=value" syntax, and look for the cases where we can
	// safely deduce the "--arg" flag from the short "-a" version when there's no value expected
	bool matched_current = false;
	if (arg.starts_with(flag.name) &&
	(arg.size() == flag.name.size() \|\| (flag.num_args > 0 && arg[flag.name.size()] == '='))) {
	matched_current = true;
	} else if (flag.num_args == 0 && matchShortArg(arg, flag)) {
	matched_current = true;
	// It matches, now need to make sure no other flag would match as well.
	// This is really inefficient, but we don't expect to have enough flags for it to matter
	// (famous last words).
	for (const Flag& other_flag : flags_) {
	if (&other_flag == &flag) {
	continue;
	}
	if (matchShortArg(arg, other_flag)) {
	matched_current = false; // ambiguous, skip this match
	break;
	}
	}
	}
	if (!matched_current) {
	continue;
	}

	if (flag.num_args > 0) {
	if (arg.size() == flag.name.size()) {
	i++;
	if (i >= args.size()) {
	*out_error << flag.name << " missing argument.\n\n";
	Usage(out_error);
	return 1;
	}
	arg = args[i];
	} else {
	arg.remove_prefix(flag.name.size() + 1);
	// Disallow empty arguments after '='.
	if (arg.empty()) {
	*out_error << flag.name << " has empty argument.\n\n";
	Usage(out_error);
	return 1;
	}
	}
	if (!flag.action(arg, out_error)) {
	return 1;
	}
	} else {
	if (!flag.action({}, out_error)) {
	return 1;
	}
	}
	flag.found = true;
	match = true;
	break;
	}

	if (!match) {
	*out_error << "unknown option '" << arg << "'.\n\n";
	Usage(out_error);
	return 1;
	}
	}

	for (const Flag& flag : flags_) {
	if (flag.is_required && !flag.found) {
	*out_error << "missing required flag " << flag.name << "\n\n";
	Usage(out_error);
	return 1;
	}
	}

	return Action(file_args);
	}

	} // namespace aapt