| // Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors |
| // Licensed under the MIT License: |
| // |
| // Permission is hereby granted, free of charge, to any person obtaining a copy |
| // of this software and associated documentation files (the "Software"), to deal |
| // in the Software without restriction, including without limitation the rights |
| // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell |
| // copies of the Software, and to permit persons to whom the Software is |
| // furnished to do so, subject to the following conditions: |
| // |
| // The above copyright notice and this permission notice shall be included in |
| // all copies or substantial portions of the Software. |
| // |
| // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR |
| // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, |
| // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE |
| // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER |
| // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, |
| // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN |
| // THE SOFTWARE. |
| |
| #ifndef _GNU_SOURCE |
| #define _GNU_SOURCE |
| #endif |
| |
| #if _WIN32 |
| #include "win32-api-version.h" |
| #endif |
| |
| #include "main.h" |
| #include "debug.h" |
| #include "arena.h" |
| #include "miniposix.h" |
| #include <map> |
| #include <set> |
| #include <stdlib.h> |
| #include <errno.h> |
| #include <limits.h> |
| |
| #if _WIN32 |
| #include <windows.h> |
| #include "windows-sanity.h" |
| #else |
| #include <sys/uio.h> |
| #endif |
| |
| namespace kj { |
| |
| // ======================================================================================= |
| |
| TopLevelProcessContext::TopLevelProcessContext(StringPtr programName) |
| : programName(programName), |
| cleanShutdown(getenv("KJ_CLEAN_SHUTDOWN") != nullptr) { |
| printStackTraceOnCrash(); |
| } |
| |
| StringPtr TopLevelProcessContext::getProgramName() { |
| return programName; |
| } |
| |
| void TopLevelProcessContext::exit() { |
| int exitCode = hadErrors ? 1 : 0; |
| if (cleanShutdown) { |
| #if KJ_NO_EXCEPTIONS |
| // This is the best we can do. |
| warning("warning: KJ_CLEAN_SHUTDOWN may not work correctly when compiled " |
| "with -fno-exceptions."); |
| ::exit(exitCode); |
| #else |
| throw CleanShutdownException { exitCode }; |
| #endif |
| } |
| _exit(exitCode); |
| } |
| |
| #if _WIN32 |
| void setStandardIoMode(int fd) { |
| // Set mode to binary if the fd is not a console. |
| HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd)); |
| DWORD consoleMode; |
| if (GetConsoleMode(handle, &consoleMode)) { |
| // It's a console. |
| } else { |
| KJ_SYSCALL(_setmode(fd, _O_BINARY)); |
| } |
| } |
| #else |
| void setStandardIoMode(int fd) {} |
| #endif |
| |
| static void writeLineToFd(int fd, StringPtr message) { |
| // Write the given message to the given file descriptor with a trailing newline iff the message |
| // is non-empty and doesn't already have a trailing newline. We use writev() to do this in a |
| // single system call without any copying (OS permitting). |
| |
| if (message.size() == 0) { |
| return; |
| } |
| |
| #if _WIN32 |
| KJ_STACK_ARRAY(char, newlineExpansionBuffer, 2 * (message.size() + 1), 128, 512); |
| char* p = newlineExpansionBuffer.begin(); |
| for(char ch : message) { |
| if(ch == '\n') { |
| *(p++) = '\r'; |
| } |
| *(p++) = ch; |
| } |
| if(!message.endsWith("\n")) { |
| *(p++) = '\r'; |
| *(p++) = '\n'; |
| } |
| |
| size_t newlineExpandedSize = p - newlineExpansionBuffer.begin(); |
| |
| KJ_ASSERT(newlineExpandedSize <= newlineExpansionBuffer.size()); |
| |
| HANDLE handle = reinterpret_cast<HANDLE>(_get_osfhandle(fd)); |
| DWORD consoleMode; |
| bool redirectedToFile = !GetConsoleMode(handle, &consoleMode); |
| |
| DWORD writtenSize; |
| if(redirectedToFile) { |
| WriteFile(handle, newlineExpansionBuffer.begin(), newlineExpandedSize, &writtenSize, nullptr); |
| } else { |
| KJ_STACK_ARRAY(wchar_t, buffer, newlineExpandedSize, 128, 512); |
| |
| size_t finalSize = MultiByteToWideChar( |
| CP_UTF8, |
| 0, |
| newlineExpansionBuffer.begin(), |
| newlineExpandedSize, |
| buffer.begin(), |
| buffer.size()); |
| |
| KJ_ASSERT(finalSize <= buffer.size()); |
| |
| WriteConsoleW(handle, buffer.begin(), finalSize, &writtenSize, nullptr); |
| } |
| #else |
| // Unfortunately the writev interface requires non-const pointers even though it won't modify |
| // the data. |
| struct iovec vec[2]; |
| vec[0].iov_base = const_cast<char*>(message.begin()); |
| vec[0].iov_len = message.size(); |
| vec[1].iov_base = const_cast<char*>("\n"); |
| vec[1].iov_len = 1; |
| |
| struct iovec* pos = vec; |
| |
| // Only use the second item in the vec if the message doesn't already end with \n. |
| uint count = message.endsWith("\n") ? 1 : 2; |
| |
| for (;;) { |
| ssize_t n = writev(fd, pos, count); |
| if (n < 0) { |
| if (errno == EINTR) { |
| continue; |
| } else { |
| // This function is meant for writing to stdout and stderr. If writes fail on those FDs |
| // there's not a whole lot we can reasonably do, so just ignore it. |
| return; |
| } |
| } |
| |
| // Update chunks to discard what was successfully written. |
| for (;;) { |
| if (count == 0) { |
| // Done writing. |
| return; |
| } else if (pos->iov_len <= implicitCast<size_t>(n)) { |
| // Wrote this entire chunk. |
| n -= pos->iov_len; |
| ++pos; |
| --count; |
| } else { |
| // Wrote only part of this chunk. Adjust the pointer and then retry. |
| pos->iov_base = reinterpret_cast<byte*>(pos->iov_base) + n; |
| pos->iov_len -= n; |
| break; |
| } |
| } |
| } |
| #endif |
| } |
| |
| void TopLevelProcessContext::warning(StringPtr message) { |
| writeLineToFd(STDERR_FILENO, message); |
| } |
| |
| void TopLevelProcessContext::error(StringPtr message) { |
| hadErrors = true; |
| writeLineToFd(STDERR_FILENO, message); |
| } |
| |
| void TopLevelProcessContext::exitError(StringPtr message) { |
| error(message); |
| exit(); |
| } |
| |
| void TopLevelProcessContext::exitInfo(StringPtr message) { |
| writeLineToFd(STDOUT_FILENO, message); |
| exit(); |
| } |
| |
| void TopLevelProcessContext::increaseLoggingVerbosity() { |
| // At the moment, there is only one log level that isn't enabled by default. |
| _::Debug::setLogLevel(_::Debug::Severity::INFO); |
| } |
| |
| // ======================================================================================= |
| |
| int runMainAndExit(ProcessContext& context, MainFunc&& func, int argc, char* argv[]) { |
| setStandardIoMode(STDIN_FILENO); |
| setStandardIoMode(STDOUT_FILENO); |
| setStandardIoMode(STDERR_FILENO); |
| |
| #if !KJ_NO_EXCEPTIONS |
| try { |
| #endif |
| KJ_ASSERT(argc > 0); |
| |
| KJ_STACK_ARRAY(StringPtr, params, argc - 1, 8, 32); |
| for (int i = 1; i < argc; i++) { |
| params[i - 1] = argv[i]; |
| } |
| |
| KJ_IF_MAYBE(exception, runCatchingExceptions([&]() { |
| func(argv[0], params); |
| })) { |
| context.error(str("*** Uncaught exception ***\n", *exception)); |
| } |
| context.exit(); |
| #if !KJ_NO_EXCEPTIONS |
| } catch (const TopLevelProcessContext::CleanShutdownException& e) { |
| return e.exitCode; |
| } |
| #endif |
| KJ_CLANG_KNOWS_THIS_IS_UNREACHABLE_BUT_GCC_DOESNT |
| } |
| |
| // ======================================================================================= |
| |
| struct MainBuilder::Impl { |
| inline Impl(ProcessContext& context, StringPtr version, |
| StringPtr briefDescription, StringPtr extendedDescription) |
| : context(context), version(version), |
| briefDescription(briefDescription), extendedDescription(extendedDescription) {} |
| |
| ProcessContext& context; |
| StringPtr version; |
| StringPtr briefDescription; |
| StringPtr extendedDescription; |
| |
| Arena arena; |
| |
| struct CharArrayCompare { |
| inline bool operator()(const ArrayPtr<const char>& a, const ArrayPtr<const char>& b) const { |
| int cmp = memcmp(a.begin(), b.begin(), min(a.size(), b.size())); |
| if (cmp == 0) { |
| return a.size() < b.size(); |
| } else { |
| return cmp < 0; |
| } |
| } |
| }; |
| |
| struct Option { |
| ArrayPtr<OptionName> names; |
| bool hasArg; |
| union { |
| Function<Validity()>* func; |
| Function<Validity(StringPtr)>* funcWithArg; |
| }; |
| StringPtr argTitle; |
| StringPtr helpText; |
| }; |
| |
| class OptionDisplayOrder; |
| |
| std::map<char, Option*> shortOptions; |
| std::map<ArrayPtr<const char>, Option*, CharArrayCompare> longOptions; |
| |
| struct SubCommand { |
| Function<MainFunc()> func; |
| StringPtr helpText; |
| }; |
| std::map<StringPtr, SubCommand> subCommands; |
| |
| struct Arg { |
| StringPtr title; |
| Function<Validity(StringPtr)> callback; |
| uint minCount; |
| uint maxCount; |
| }; |
| |
| Vector<Arg> args; |
| |
| Maybe<Function<Validity()>> finalCallback; |
| |
| Option& addOption(std::initializer_list<OptionName> names, bool hasArg, StringPtr helpText) { |
| KJ_REQUIRE(names.size() > 0, "option must have at least one name"); |
| |
| Option& option = arena.allocate<Option>(); |
| option.names = arena.allocateArray<OptionName>(names.size()); |
| uint i = 0; |
| for (auto& name: names) { |
| option.names[i++] = name; |
| if (name.isLong) { |
| KJ_REQUIRE( |
| longOptions.insert(std::make_pair(StringPtr(name.longName).asArray(), &option)).second, |
| "duplicate option", name.longName); |
| } else { |
| KJ_REQUIRE( |
| shortOptions.insert(std::make_pair(name.shortName, &option)).second, |
| "duplicate option", name.shortName); |
| } |
| } |
| option.hasArg = hasArg; |
| option.helpText = helpText; |
| return option; |
| } |
| |
| Validity printVersion() { |
| context.exitInfo(version); |
| return true; |
| } |
| |
| Validity increaseVerbosity() { |
| context.increaseLoggingVerbosity(); |
| return true; |
| } |
| }; |
| |
| MainBuilder::MainBuilder(ProcessContext& context, StringPtr version, |
| StringPtr briefDescription, StringPtr extendedDescription) |
| : impl(heap<Impl>(context, version, briefDescription, extendedDescription)) { |
| addOption({"verbose"}, KJ_BIND_METHOD(*impl, increaseVerbosity), |
| "Log informational messages to stderr; useful for debugging."); |
| addOption({"version"}, KJ_BIND_METHOD(*impl, printVersion), |
| "Print version information and exit."); |
| } |
| |
| MainBuilder::~MainBuilder() noexcept(false) {} |
| |
| MainBuilder& MainBuilder::addOption(std::initializer_list<OptionName> names, |
| Function<Validity()> callback, |
| StringPtr helpText) { |
| impl->addOption(names, false, helpText).func = &impl->arena.copy(kj::mv(callback)); |
| return *this; |
| } |
| |
| MainBuilder& MainBuilder::addOptionWithArg(std::initializer_list<OptionName> names, |
| Function<Validity(StringPtr)> callback, |
| StringPtr argumentTitle, StringPtr helpText) { |
| auto& opt = impl->addOption(names, true, helpText); |
| opt.funcWithArg = &impl->arena.copy(kj::mv(callback)); |
| opt.argTitle = argumentTitle; |
| return *this; |
| } |
| |
| MainBuilder& MainBuilder::addSubCommand(StringPtr name, Function<MainFunc()> getSubParser, |
| StringPtr helpText) { |
| KJ_REQUIRE(impl->args.size() == 0, "cannot have sub-commands when expecting arguments"); |
| KJ_REQUIRE(impl->finalCallback == nullptr, |
| "cannot have a final callback when accepting sub-commands"); |
| KJ_REQUIRE( |
| impl->subCommands.insert(std::make_pair( |
| name, Impl::SubCommand { kj::mv(getSubParser), helpText })).second, |
| "duplicate sub-command", name); |
| return *this; |
| } |
| |
| MainBuilder& MainBuilder::expectArg(StringPtr title, Function<Validity(StringPtr)> callback) { |
| KJ_REQUIRE(impl->subCommands.empty(), "cannot have sub-commands when expecting arguments"); |
| impl->args.add(Impl::Arg { title, kj::mv(callback), 1, 1 }); |
| return *this; |
| } |
| MainBuilder& MainBuilder::expectOptionalArg( |
| StringPtr title, Function<Validity(StringPtr)> callback) { |
| KJ_REQUIRE(impl->subCommands.empty(), "cannot have sub-commands when expecting arguments"); |
| impl->args.add(Impl::Arg { title, kj::mv(callback), 0, 1 }); |
| return *this; |
| } |
| MainBuilder& MainBuilder::expectZeroOrMoreArgs( |
| StringPtr title, Function<Validity(StringPtr)> callback) { |
| KJ_REQUIRE(impl->subCommands.empty(), "cannot have sub-commands when expecting arguments"); |
| impl->args.add(Impl::Arg { title, kj::mv(callback), 0, UINT_MAX }); |
| return *this; |
| } |
| MainBuilder& MainBuilder::expectOneOrMoreArgs( |
| StringPtr title, Function<Validity(StringPtr)> callback) { |
| KJ_REQUIRE(impl->subCommands.empty(), "cannot have sub-commands when expecting arguments"); |
| impl->args.add(Impl::Arg { title, kj::mv(callback), 1, UINT_MAX }); |
| return *this; |
| } |
| |
| MainBuilder& MainBuilder::callAfterParsing(Function<Validity()> callback) { |
| KJ_REQUIRE(impl->finalCallback == nullptr, "callAfterParsing() can only be called once"); |
| KJ_REQUIRE(impl->subCommands.empty(), "cannot have a final callback when accepting sub-commands"); |
| impl->finalCallback = kj::mv(callback); |
| return *this; |
| } |
| |
| class MainBuilder::MainImpl { |
| public: |
| MainImpl(Own<Impl>&& impl): impl(kj::mv(impl)) {} |
| |
| void operator()(StringPtr programName, ArrayPtr<const StringPtr> params); |
| |
| private: |
| Own<Impl> impl; |
| |
| KJ_NORETURN(void usageError(StringPtr programName, StringPtr message)); |
| KJ_NORETURN(void printHelp(StringPtr programName)); |
| void wrapText(Vector<char>& output, StringPtr indent, StringPtr text); |
| }; |
| |
| MainFunc MainBuilder::build() { |
| return MainImpl(kj::mv(impl)); |
| } |
| |
| void MainBuilder::MainImpl::operator()(StringPtr programName, ArrayPtr<const StringPtr> params) { |
| Vector<StringPtr> arguments; |
| |
| for (size_t i = 0; i < params.size(); i++) { |
| StringPtr param = params[i]; |
| if (param == "--") { |
| // "--" ends option parsing. |
| arguments.addAll(params.begin() + i + 1, params.end()); |
| break; |
| } else if (param.startsWith("--")) { |
| // Long option. |
| ArrayPtr<const char> name; |
| Maybe<StringPtr> maybeArg; |
| KJ_IF_MAYBE(pos, param.findFirst('=')) { |
| name = param.slice(2, *pos); |
| maybeArg = param.slice(*pos + 1); |
| } else { |
| name = param.slice(2); |
| } |
| auto iter = impl->longOptions.find(name); |
| if (iter == impl->longOptions.end()) { |
| if (param == "--help") { |
| printHelp(programName); |
| } else { |
| usageError(programName, str("--", name, ": unrecognized option")); |
| } |
| } else { |
| const Impl::Option& option = *iter->second; |
| if (option.hasArg) { |
| // Argument expected. |
| KJ_IF_MAYBE(arg, maybeArg) { |
| // "--foo=blah": "blah" is the argument. |
| KJ_IF_MAYBE(error, (*option.funcWithArg)(*arg).releaseError()) { |
| usageError(programName, str(param, ": ", *error)); |
| } |
| } else if (i + 1 < params.size() && |
| !(params[i + 1].startsWith("-") && params[i + 1].size() > 1)) { |
| // "--foo blah": "blah" is the argument. |
| ++i; |
| KJ_IF_MAYBE(error, (*option.funcWithArg)(params[i]).releaseError()) { |
| usageError(programName, str(param, "=", params[i], ": ", *error)); |
| } |
| } else { |
| usageError(programName, str("--", name, ": missing argument")); |
| } |
| } else { |
| // No argument expected. |
| if (maybeArg == nullptr) { |
| KJ_IF_MAYBE(error, (*option.func)().releaseError()) { |
| usageError(programName, str(param, ": ", *error)); |
| } |
| } else { |
| usageError(programName, str("--", name, ": option does not accept an argument")); |
| } |
| } |
| } |
| } else if (param.startsWith("-") && param.size() > 1) { |
| // Short option(s). |
| for (uint j = 1; j < param.size(); j++) { |
| char c = param[j]; |
| auto iter = impl->shortOptions.find(c); |
| if (iter == impl->shortOptions.end()) { |
| usageError(programName, str("-", c, ": unrecognized option")); |
| } else { |
| const Impl::Option& option = *iter->second; |
| if (option.hasArg) { |
| // Argument expected. |
| if (j + 1 < param.size()) { |
| // Rest of flag is argument. |
| StringPtr arg = param.slice(j + 1); |
| KJ_IF_MAYBE(error, (*option.funcWithArg)(arg).releaseError()) { |
| usageError(programName, str("-", c, " ", arg, ": ", *error)); |
| } |
| break; |
| } else if (i + 1 < params.size() && |
| !(params[i + 1].startsWith("-") && params[i + 1].size() > 1)) { |
| // Next parameter is argument. |
| ++i; |
| KJ_IF_MAYBE(error, (*option.funcWithArg)(params[i]).releaseError()) { |
| usageError(programName, str("-", c, " ", params[i], ": ", *error)); |
| } |
| break; |
| } else { |
| usageError(programName, str("-", c, ": missing argument")); |
| } |
| } else { |
| // No argument expected. |
| KJ_IF_MAYBE(error, (*option.func)().releaseError()) { |
| usageError(programName, str("-", c, ": ", *error)); |
| } |
| } |
| } |
| } |
| } else if (!impl->subCommands.empty()) { |
| // A sub-command name. |
| auto iter = impl->subCommands.find(param); |
| if (iter != impl->subCommands.end()) { |
| MainFunc subMain = iter->second.func(); |
| subMain(str(programName, ' ', param), params.slice(i + 1, params.size())); |
| return; |
| } else if (param == "help") { |
| if (i + 1 < params.size()) { |
| iter = impl->subCommands.find(params[i + 1]); |
| if (iter != impl->subCommands.end()) { |
| // Run the sub-command with "--help" as the argument. |
| MainFunc subMain = iter->second.func(); |
| StringPtr dummyArg = "--help"; |
| subMain(str(programName, ' ', params[i + 1]), arrayPtr(&dummyArg, 1)); |
| return; |
| } else if (params[i + 1] == "help") { |
| uint count = 0; |
| for (uint j = i + 2; |
| j < params.size() && (params[j] == "help" || params[j] == "--help"); |
| j++) { |
| ++count; |
| } |
| |
| switch (count) { |
| case 0: |
| impl->context.exitInfo("Help about help? We must go deeper..."); |
| break; |
| case 1: |
| impl->context.exitInfo( |
| "Yo dawg, I heard you like help. So I wrote you some help about how to use " |
| "help so you can get help on help."); |
| break; |
| case 2: |
| impl->context.exitInfo("Help, I'm trapped in a help text factory!"); |
| break; |
| default: |
| if (count < 10) { |
| impl->context.exitError("Killed by signal 911 (SIGHELP)"); |
| } else { |
| impl->context.exitInfo("How to keep an idiot busy..."); |
| } |
| break; |
| } |
| } else { |
| usageError(programName, str(params[i + 1], ": unknown command")); |
| } |
| } else { |
| printHelp(programName); |
| } |
| } else { |
| // Arguments are not accepted, so this is an error. |
| usageError(programName, str(param, ": unknown command")); |
| } |
| } else { |
| // Just a regular argument. |
| arguments.add(param); |
| } |
| } |
| |
| // ------------------------------------ |
| // Handle arguments. |
| // ------------------------------------ |
| |
| if (!impl->subCommands.empty()) { |
| usageError(programName, "missing command"); |
| } |
| |
| // Count the number of required arguments, so that we know how to distribute the optional args. |
| uint requiredArgCount = 0; |
| for (auto& argSpec: impl->args) { |
| requiredArgCount += argSpec.minCount; |
| } |
| |
| // Now go through each argument spec and consume arguments with it. |
| StringPtr* argPos = arguments.begin(); |
| for (auto& argSpec: impl->args) { |
| uint i = 0; |
| for (; i < argSpec.minCount; i++) { |
| if (argPos == arguments.end()) { |
| usageError(programName, str("missing argument ", argSpec.title)); |
| } else { |
| KJ_IF_MAYBE(error, argSpec.callback(*argPos).releaseError()) { |
| usageError(programName, str(*argPos, ": ", *error)); |
| } |
| ++argPos; |
| --requiredArgCount; |
| } |
| } |
| |
| // If we have more arguments than we need, and this argument spec will accept extras, give |
| // them to it. |
| for (; i < argSpec.maxCount && arguments.end() - argPos > requiredArgCount; ++i) { |
| KJ_IF_MAYBE(error, argSpec.callback(*argPos).releaseError()) { |
| usageError(programName, str(*argPos, ": ", *error)); |
| } |
| ++argPos; |
| } |
| } |
| |
| // Did we consume all the arguments? |
| while (argPos < arguments.end()) { |
| usageError(programName, str(*argPos++, ": too many arguments")); |
| } |
| |
| // Run the final callback, if any. |
| KJ_IF_MAYBE(f, impl->finalCallback) { |
| KJ_IF_MAYBE(error, (*f)().releaseError()) { |
| usageError(programName, *error); |
| } |
| } |
| } |
| |
| void MainBuilder::MainImpl::usageError(StringPtr programName, StringPtr message) { |
| impl->context.exitError(kj::str( |
| programName, ": ", message, |
| "\nTry '", programName, " --help' for more information.")); |
| KJ_CLANG_KNOWS_THIS_IS_UNREACHABLE_BUT_GCC_DOESNT |
| } |
| |
| class MainBuilder::Impl::OptionDisplayOrder { |
| public: |
| bool operator()(const Option* a, const Option* b) const { |
| if (a == b) return false; |
| |
| char aShort = '\0'; |
| char bShort = '\0'; |
| |
| for (auto& name: a->names) { |
| if (name.isLong) { |
| if (aShort == '\0') { |
| aShort = name.longName[0]; |
| } |
| } else { |
| aShort = name.shortName; |
| break; |
| } |
| } |
| for (auto& name: b->names) { |
| if (name.isLong) { |
| if (bShort == '\0') { |
| bShort = name.longName[0]; |
| } |
| } else { |
| bShort = name.shortName; |
| break; |
| } |
| } |
| |
| if (aShort < bShort) return true; |
| if (aShort > bShort) return false; |
| |
| StringPtr aLong; |
| StringPtr bLong; |
| |
| for (auto& name: a->names) { |
| if (name.isLong) { |
| aLong = name.longName; |
| break; |
| } |
| } |
| for (auto& name: b->names) { |
| if (name.isLong) { |
| bLong = name.longName; |
| break; |
| } |
| } |
| |
| return aLong < bLong; |
| } |
| }; |
| |
| void MainBuilder::MainImpl::printHelp(StringPtr programName) { |
| Vector<char> text(1024); |
| |
| std::set<const Impl::Option*, Impl::OptionDisplayOrder> sortedOptions; |
| |
| for (auto& entry: impl->shortOptions) { |
| sortedOptions.insert(entry.second); |
| } |
| for (auto& entry: impl->longOptions) { |
| sortedOptions.insert(entry.second); |
| } |
| |
| text.addAll(str("Usage: ", programName, sortedOptions.empty() ? "" : " [<option>...]")); |
| |
| if (impl->subCommands.empty()) { |
| for (auto& arg: impl->args) { |
| text.add(' '); |
| if (arg.minCount == 0) { |
| text.addAll(str("[", arg.title, arg.maxCount > 1 ? "...]" : "]")); |
| } else { |
| text.addAll(str(arg.title, arg.maxCount > 1 ? "..." : "")); |
| } |
| } |
| } else { |
| text.addAll(StringPtr(" <command> [<arg>...]")); |
| } |
| text.addAll(StringPtr("\n\n")); |
| |
| wrapText(text, "", impl->briefDescription); |
| |
| if (!impl->subCommands.empty()) { |
| text.addAll(StringPtr("\nCommands:\n")); |
| size_t maxLen = 0; |
| for (auto& command: impl->subCommands) { |
| maxLen = kj::max(maxLen, command.first.size()); |
| } |
| for (auto& command: impl->subCommands) { |
| text.addAll(StringPtr(" ")); |
| text.addAll(command.first); |
| for (size_t i = command.first.size(); i < maxLen; i++) { |
| text.add(' '); |
| } |
| text.addAll(StringPtr(" ")); |
| text.addAll(command.second.helpText); |
| text.add('\n'); |
| } |
| text.addAll(str( |
| "\nSee '", programName, " help <command>' for more information on a specific command.\n")); |
| } |
| |
| if (!sortedOptions.empty()) { |
| text.addAll(StringPtr("\nOptions:\n")); |
| |
| for (auto opt: sortedOptions) { |
| text.addAll(StringPtr(" ")); |
| bool isFirst = true; |
| for (auto& name: opt->names) { |
| if (isFirst) { |
| isFirst = false; |
| } else { |
| text.addAll(StringPtr(", ")); |
| } |
| if (name.isLong) { |
| text.addAll(str("--", name.longName)); |
| if (opt->hasArg) { |
| text.addAll(str("=", opt->argTitle)); |
| } |
| } else { |
| text.addAll(str("-", name.shortName)); |
| if (opt->hasArg) { |
| text.addAll(opt->argTitle); |
| } |
| } |
| } |
| text.add('\n'); |
| wrapText(text, " ", opt->helpText); |
| } |
| |
| text.addAll(StringPtr(" --help\n Display this help text and exit.\n")); |
| } |
| |
| if (impl->extendedDescription.size() > 0) { |
| text.add('\n'); |
| wrapText(text, "", impl->extendedDescription); |
| } |
| |
| text.add('\0'); |
| impl->context.exitInfo(String(text.releaseAsArray())); |
| KJ_CLANG_KNOWS_THIS_IS_UNREACHABLE_BUT_GCC_DOESNT |
| } |
| |
| void MainBuilder::MainImpl::wrapText(Vector<char>& output, StringPtr indent, StringPtr text) { |
| uint width = 80 - indent.size(); |
| |
| while (text.size() > 0) { |
| output.addAll(indent); |
| |
| KJ_IF_MAYBE(lineEnd, text.findFirst('\n')) { |
| if (*lineEnd <= width) { |
| output.addAll(text.slice(0, *lineEnd + 1)); |
| text = text.slice(*lineEnd + 1); |
| continue; |
| } |
| } |
| |
| if (text.size() <= width) { |
| output.addAll(text); |
| output.add('\n'); |
| break; |
| } |
| |
| uint wrapPos = width; |
| for (;; wrapPos--) { |
| if (wrapPos == 0) { |
| // Hmm, no good place to break words. Just break in the middle. |
| wrapPos = width; |
| break; |
| } else if (text[wrapPos] == ' ' && text[wrapPos - 1] != ' ') { |
| // This position is a space and is preceded by a non-space. Wrap here. |
| break; |
| } |
| } |
| |
| output.addAll(text.slice(0, wrapPos)); |
| output.add('\n'); |
| |
| // Skip spaces after the text that was printed. |
| while (text[wrapPos] == ' ') { |
| ++wrapPos; |
| } |
| if (text[wrapPos] == '\n') { |
| // Huh, apparently there were a whole bunch of spaces at the end of the line followed by a |
| // newline. Skip the newline as well so we don't print a blank line. |
| ++wrapPos; |
| } |
| text = text.slice(wrapPos); |
| } |
| } |
| |
| } // namespace kj |
