1
0
forked from Alepha/Alepha
Files
Alepha/ProgramOptions.cc

436 lines
13 KiB
C++

static_assert( __cplusplus > 2020'99 );
#include "ProgramOptions.h"
#include <set>
#include <exception>
#include <Alepha/Console.h>
#include <Alepha/word_wrap.h>
#include <Alepha/AutoRAII.h>
#include <Alepha/error.h>
#include <Alepha/Utility/StaticValue.h>
#include <Alepha/System/programName.h>
namespace Alepha::Hydrogen ::detail:: ProgramOptions_m
{
namespace
{
namespace C
{
const bool debug= false;
const bool debugMatching= false or C::debug;
const bool debugExclusions= false or C::debug;
}
using namespace std::literals::string_literals;
using Utility::StaticValue;
struct OptionMissingArgumentError
: virtual std::runtime_error
{
using std::runtime_error::runtime_error;
};
}
struct impl::ProgramOption
{
std::function< void ( std::optional< std::string > ) > handler;
std::ostringstream help;
std::function< std::string () > defaultBuilder= [] { return ""; };
std::map< std::type_index, std::set< const DomainBase * > > domains;
};
namespace
{
StaticValue< std::map< std::string, impl::ProgramOption > > programOptions;
std::vector< std::string >
allOptionNames()
{
std::vector< std::string > rv;
for( const auto &[ name, _ ]: programOptions() ) rv.push_back( name );
return rv;
}
struct ExclusivityEntry
{
std::optional< std::string > previous;
};
StaticValue< std::map< const DomainBase *, ExclusivityEntry > > mutuallyExclusiveOptions;
// The required options have to live in a single global collection. There's only one
// set of program options per execution, so this entire list has to be searched.
StaticValue< std::map< const DomainBase *, std::vector< std::string > > > requiredOptions;
}
void
impl::checkArgument( const std::optional< std::string > &argument, const std::string &name )
{
if( argument.has_value() ) return;
throw OptionMissingArgumentError( '`' + name + "` requires an argument." );
}
const OptionBinding &
OptionBinding::bindDomain( const DomainBase &domain ) const
{
if( domain.kind == typeid( RequirementDomain ) )
{
requiredOptions()[ &domain ].push_back( name );
}
option->domains[ domain.kind ].insert( &domain );
return *this;
}
std::ostream &
OptionBinding::operator << ( std::function< void () > core ) const
{
// So that users do not have to implement their own checking for argument absent,
// we do it for them.
auto handler= [core, name= name]( const std::optional< std::string > s )
{
if( s.has_value() )
{
throw std::runtime_error( "`--" + name + "` takes no arguments, but `" + s.value()
+ " was provided." );
}
return core();
};
return registerHandler( handler );
}
std::ostream &
OptionBinding::operator << ( std::function< void ( std::string ) > core ) const
{
// So that users do not have to implement their own checking for argument present,
// we do it for them.
auto handler= [core, name= name]( const std::optional< std::string > argument )
{
impl::checkArgument( argument, name );
return core( argument.value() );
};
return registerHandler( handler );
}
void
OptionBinding::setDefaultBuilder( std::function< std::string () > builder ) const
{
option->defaultBuilder= builder;
}
std::ostream &
OptionBinding::registerHandler( std::function< void ( std::optional< std::string > ) > handler ) const
{
option->handler= handler;
return option->help;
}
namespace
{
void
incompatibleHelpText( std::ostream &out, const std::string &name, const auto &domains, const auto &exclusivityMembers )
{
if( not domains.contains( typeid( ExclusivityDomain ) )
or domains.at( typeid( ExclusivityDomain ) ).empty() )
{
return;
}
std::set< std::string > incompatibles;
for( const auto &domain: domains.at( typeid( ExclusivityDomain ) ) )
{
std::transform( exclusivityMembers.lower_bound( domain ),
exclusivityMembers.upper_bound( domain ),
std::inserter( incompatibles, end( incompatibles ) ),
[]( const auto &item ) { return item.second; } );
}
incompatibles.erase( name );
if( incompatibles.empty() ) return;
out << "\nIncompatible with: \n\n";
bool first= true;
for( const auto &incompat: incompatibles )
{
if( not first ) out << ", ";
first= false;
out << '`' << incompat << '`';
}
out << std::endl;
}
void
printAllOptionsHelp( const std::optional< std::string > canonicalProgramName )
{
const auto longestOption= std::max_element( begin( programOptions() ), end( programOptions() ),
[]( const auto &lhs, const auto &rhs )
{
return lhs.first.size() < rhs.first.size();
} );
// Account for the `:` and the ` ` in the output table format.
const std::size_t alignmentWidth= longestOption->first.size() + 2;
//
std::multimap< const DomainBase *, std::string > exclusivityMembers;
for( const auto &[ name, def ]: programOptions() )
{
if( not def.domains.contains( typeid( ExclusivityDomain ) ) ) continue;
for( const auto &excl: def.domains.at( typeid( ExclusivityDomain ) ) )
{
exclusivityMembers.emplace( excl, name );
}
}
const std::size_t width= getConsoleWidth();
std::cout << StartWrap{ width };
std::cout << "Options:" << std::endl << std::endl;
std::cout << EndWrap;
// Inspect and print each option.
for( const auto &[ name, def ]: programOptions() )
{
// When turning off wrapping, here, we also emit a newline between entries.
AutoRAII endline{ []{}, []{ std::cout << std::endl; } };
auto wrapping= adaptStream( StartWrap{ width, alignmentWidth }, std::cout );
const auto &[ _, helpText, defaultBuilder, domains ]= def;
VariableMap substitutions=
{
{ "program-name"s, lambaste<=System::programName() },
{ "option-name"s, lambaste<=name },
{ "default"s, [&defaultBuilder= defaultBuilder, &name= name]
{
return "Default is `" + name + defaultBuilder() + "`";
} },
};
if( canonicalProgramName.has_value() )
{
substitutions[ "canonical-name"s ]= lambaste<=canonicalProgramName.value();
}
auto substitution= adaptStream( StartSubstitutions{ '!', substitutions }, std::cout );
// How much unused of the max width there will be
const std::size_t padding= alignmentWidth - name.size() - 2;
std::cout << name << ": " << std::string( padding, ' ' ) << helpText.str() << '\n';
// Append the incompatibility text, when we see mutually-exclusive options.
incompatibleHelpText( std::cout, name, domains, exclusivityMembers );
}
// Check for required options, and print a summary of those:
if( not requiredOptions().empty() ) for( const auto &[ _, group ]: requiredOptions() )
{
std::cout << StartWrap{ width };
std::cout << "At least one of the options in this group are required: ";
bool first= true;
for( const auto &required: group )
{
if( not first ) std::cout << ", ";
first= false;
std::cout << '`' << required << '`';
}
std::cout << std::endl;
}
}
}
// The options which set boolean flags can be
std::ostream &
OptionBinding::operator << ( bool &flag ) const
{
--OptionString{ "no-" + name.substr( 2 ) }
<< [&flag] { flag= false; } << "Disable `" + name + "`. See that option for more details.";
return self() << [&flag] { flag= true; };
}
OptionString
literals::operator ""_option( const char *const text, const std::size_t amount )
{
return { std::string( text, text + amount ) };
}
OptionBinding
impl::operator --( const OptionString option )
{
const auto name= "--" + option.name;
if( programOptions().contains( name ) )
{
throw RepeatedProgramOptionError( "Option `" + name + "` was already registered." );
}
return OptionBinding{ name, &programOptions()[ name ] };
}
[[noreturn]] void
impl::usage( const std::string &helpMessage, const std::optional< std::string > &canonicalName )
{
if( not helpMessage.empty() )
{
VariableMap substitutions
{
{ "program-name"s, lambaste<=System::programName() },
};
if( canonicalName.has_value() ) substitutions[ "canonical-name"s ]= lambaste<=canonicalName.value();
auto wrapping= adaptStream( StartWrap{ getConsoleWidth() }, std::cout );
auto substitution= adaptStream( StartSubstitutions{ '!', substitutions }, std::cout );
std::cout << helpMessage << std::endl << std::endl;
}
printAllOptionsHelp( canonicalName );
::exit( EXIT_SUCCESS );
}
std::vector< std::string >
impl::handleOptions( const std::vector< std::string > &args, const std::function< void () > usageFunction )
{
--"help"_option << usageFunction << "Print this help message (program usage).";
// The unprocessed program arguments will be collected into this vector
std::vector< std::string > rv;
const auto &opts= programOptions();
// The arguments end at the first `--` token (by itself), or when there's no more.
const auto endOfArgs= std::find( begin( args ), end( args ), "--" );
// Because `--help` needs to expand certain variables, options which can affect it need to be processed
// before handling `--help`
const bool helpRequested= std::find( begin( args ), endOfArgs, "--help" ) != endOfArgs;
// Each time a required domain is seen, we put that requirement into this set.
// If all required options are passed, then this set should match the list of
// required option domains.
std::set< const DomainBase * > requiredOptionsSeen;
const std::vector< std::string > argsToProcess{ begin( args ), endOfArgs };
// An option that requires an argument might have been type-o'ed as `--option arg`
// instead of `--option=arg`. By tracking the next option, we can print helpful
// diagnostics in the error messages.
auto next= begin( argsToProcess );
for( const auto &param: argsToProcess )
try
{
++next;
// Because `--help` has a special relationship with the rest of the options,
// we skip it in this pass.
if( helpRequested and param == "--help" ) continue;
// Match up each argument.
const bool matched= evaluate <=[&]
{
// TODO: Make this into direct map lookups.
// It requires modifying `--` options as passed, to strip `=` before
// doing a map lookup.
for( const auto &[ name, def ]: opts )
{
if( C::debugMatching ) error() << "Attempting to match `" << name << "` to `" << param << "`" << std::endl;
const auto &handler= def.handler;
std::optional< std::string > argument;
if( param == name ) argument= std::nullopt;
else if( param.starts_with( name ) and "=:"s.find( param.at( name.size() ) ) != std::string::npos )
{
argument= param.substr( name.size() + 1 );
}
else continue;
// Skip options that do not affect help, when we're doing a `--help` run.
if( helpRequested and not def.domains.contains( typeid( PreHelpDomain ) ) ) return true;
// Exclusivity has to be handled as a running concern across options...
if( def.domains.contains( typeid( ExclusivityDomain ) ) )
{
const auto &exclusions= def.domains.at( typeid( ExclusivityDomain ) );
if( C::debugExclusions )
{
error() << "I see " << exclusions.size() << " mutual exclusions against `"
<< name << "`" << std::endl;
}
for( const auto &exclusion: exclusions )
{
// Look up this domain, and see if something from it was used.
auto &other= mutuallyExclusiveOptions()[ exclusion ].previous;
if( other.has_value() and other != name )
{
throw std::runtime_error{ "Options `" + other.value() + "` and `"
+ name + "` are mutually exclusive." };
}
else other= name; // If nothing was there, record that this name was now used.
}
}
// If the option was required, mark that we took it.
if( def.domains.contains( typeid( RequirementDomain ) ) )
{
for( const auto &domain: def.domains.at( typeid( RequirementDomain ) ) )
{
requiredOptionsSeen.insert( domain );
}
}
handler( argument );
return true;
}
return false;
};
if( C::debugMatching and not matched ) error() << "No match for `" << param << "` was found." << std::endl;
if( matched ) continue;
rv.push_back( param );
if( param.starts_with( "--" ) )
{
// TODO:
throw std::runtime_error( "`" + param + "` is an unrecognized option." );
}
}
catch( const OptionMissingArgumentError &e )
{
if( next == end( argsToProcess ) or next->starts_with( "--" ) ) throw;
throw std::runtime_error( e.what() + " did you mean: `"s + param + "=" + *next + "`?" );
}
if( endOfArgs != end( args ) ) std::copy( endOfArgs + 1, end( args ), back_inserter( rv ) );
if( helpRequested ) programOptions().at( "--help" ).handler( std::nullopt );
// If we're not doing a help-run, then we need to validate the required
// options were all passed.
if( requiredOptions().size() != requiredOptionsSeen.size() )
{
for( auto [ required, opts ]: requiredOptions() )
{
if( requiredOptionsSeen.contains( required ) ) continue;
std::ostringstream oss;
oss << "Required option missing. At least one of ";
bool first= true;
for( const auto &name: opts )
{
if( not first ) oss << ", ";
first= false;
oss << '`' << name << '`';
}
oss << " must be passed.";
throw std::runtime_error( oss.str() );
}
throw std::runtime_error{ "A required option was missing, and it couldn't be identified." };
}
return rv;
}
}