mercury/compiler/make.util.m

%-----------------------------------------------------------------------------%
% Copyright (C) 2002-2003 University of Melbourne.
% This file may only be copied under the terms of the GNU General
% Public License - see the file COPYING in the Mercury distribution.
%-----------------------------------------------------------------------------%
% File: make.util.m
% Main author: stayl
%
% Assorted predicates used to implement `mmc --make'.
%-----------------------------------------------------------------------------%

:- module make__util.

:- interface.

	%
	% Versions of foldl which stop if the supplied predicate returns `no'
	% for any element of the list.
	%

	% foldl2_pred_with_status(T, Succeeded, Info0, Info).
:- type foldl2_pred_with_status(T, Info, IO) ==
				pred(T, bool, Info, Info, IO, IO).
:- inst foldl2_pred_with_status == (pred(in, out, in, out, di, uo) is det).

	% foldl2_maybe_stop_at_error(KeepGoing, P, List,
	%	Succeeded, Info0, Info).
:- pred foldl2_maybe_stop_at_error(bool::in,
	foldl2_pred_with_status(T, Info, IO)::in(foldl2_pred_with_status),
	list(T)::in, bool::out, Info::in, Info::out, IO::di, IO::uo) is det.

	% foldl3_pred_with_status(T, Succeeded, Acc0, Acc, Info0, Info).
:- type foldl3_pred_with_status(T, Acc, Info, IO) ==
		pred(T, bool, Acc, Acc, Info, Info, IO, IO).
:- inst foldl3_pred_with_status ==
		(pred(in, out, in, out, in, out, di, uo) is det).

	% foldl3_maybe_stop_at_error(KeepGoing, P, List,
	%	Succeeded, Acc0, Acc, Info0, Info).
:- pred foldl3_maybe_stop_at_error(bool::in,
	foldl3_pred_with_status(T, Acc, Info, IO)::in(foldl3_pred_with_status),
	list(T)::in, bool::out, Acc::in, Acc::out, Info::in, Info::out,
	IO::di, IO::uo) is det.

%-----------------------------------------------------------------------------%

:- type build(T, Info) == pred(T, bool, Info, Info, io__state, io__state).
:- type build(T) == build(T, make_info).
:- inst build == (pred(in, out, in, out, di, uo) is det).

	% build_with_module_options(ModuleName, ExtraArgs, Builder,
	%	Succeeded, Info0, Info).
	%
	% Perform the given closure after updating the option_table in
	% the globals in the io__state to contain the module-specific
	% options for the specified module and the extra options given
	% in the ExtraArgs.
	% Adds `--invoked-by-mmc-make' and `--use-subdirs' to the option
	% list.
	% The old option table will be restored afterwards.
:- pred build_with_module_options(module_name::in,
	list(string)::in, build(list(string))::in(build), bool::out,
	make_info::in, make_info::out, io__state::di, io__state::uo) is det.

	% build_with_module_options(ModuleName, OptionsVariables,
	%	OptionArgs, ExtraArgs, Builder, Succeeded, Info0, Info).
	%
	% Perform the given closure after updating the option_table in
	% the globals in the io__state to contain the module-specific
	% options for the specified module and the extra options given
	% in ExtraArgs and OptionArgs 
	% Does not add `--invoked-by-mmc-make' and `--use-subdirs'
	% to the option list.
	% The old option table will be restored afterwards.
:- pred build_with_module_options(module_name::in, options_variables::in,
	list(string)::in, list(string)::in,
	build(list(string), Info)::in(build),
	bool::out, Info::in, Info::out, io__state::di, io__state::uo) is det.

	% Perform the given closure with an output stream created
	% to append to the error file for the given module.
:- pred build_with_output_redirect(module_name::in,
	build(io__output_stream)::in(build), bool::out,
	make_info::in, make_info::out, io__state::di, io__state::uo) is det.

	% Produce an output stream which writes to the error file
	% for the given module.
:- pred redirect_output(module_name::in, maybe(io__output_stream)::out,
	make_info::in, make_info::out, io__state::di, io__state::uo) is det.

	% Close the module error output stream.
:- pred unredirect_output(module_name::in, io__output_stream::in,
	make_info::in, make_info::out, io__state::di, io__state::uo) is det.

%-----------------------------------------------------------------------------%

:- type build2(T, U) == pred(T, U, bool, make_info, make_info,
				io__state, io__state).
:- inst build2 == (pred(in, in, out, in, out, di, uo) is det).

:- pred build_with_module_options_and_output_redirect(module_name::in,
	list(string)::in, build2(list(string), io__output_stream)::in(build2),
	bool::out, make_info::in, make_info::out,
	io__state::di, io__state::uo) is det.

%-----------------------------------------------------------------------------%
	% Timestamp handling.

	% Find the timestamp updated when a target is produced.
:- pred get_timestamp_file_timestamp(target_file::in,
	maybe_error(timestamp)::out, make_info::in, make_info::out,
	io__state::di, io__state::uo) is det.

	% Find the timestamp for the given dependency file.
:- pred get_dependency_timestamp(dependency_file::in,
	maybe_error(timestamp)::out, make_info::in, make_info::out,
	io__state::di, io__state::uo) is det.

	% get_target_timestamp(Search, TargetFile, Timestamp)
	%
	% Find the timestamp for the given target file.
	% `Search' should be `yes' if the file could be part of an
	% installed library.
:- pred get_target_timestamp(bool::in, target_file::in,
	maybe_error(timestamp)::out, make_info::in, make_info::out,
	io__state::di, io__state::uo) is det.

	% get_file_name(Search, TargetFile, FileName).
	%
	% Compute a file name for the given target file.
	% `Search' should be `yes' if the file could be part of an
	% installed library.
:- pred get_file_name(bool::in, target_file::in, file_name::out,
	make_info::in, make_info::out, io__state::di, io__state::uo) is det.

	% Find the timestamp of the first file matching the given
	% file name in one of the given directories.
:- pred get_file_timestamp(list(dir_name)::in, file_name::in,
	maybe_error(timestamp)::out, make_info::in, make_info::out,
	io__state::di, io__state::uo) is det.

	% Return the oldest of the timestamps if both are of the form
	% `ok(Timestamp)', returning `error(Error)' otherwise.
:- func find_oldest_timestamp(maybe_error(timestamp),
		maybe_error(timestamp)) = maybe_error(timestamp).

%-----------------------------------------------------------------------------%
	% Remove file a file, deleting the cached timestamp.

	% Remove the target file and the corresponding timestamp file.
:- pred remove_target_file(target_file::in, make_info::in, make_info::out,
	io__state::di, io__state::uo) is det.

	% Remove the target file and the corresponding timestamp file.
:- pred remove_target_file(module_name::in, module_target_type::in,
	make_info::in, make_info::out, io__state::di, io__state::uo) is det.

	% remove_file(ModuleName, Extension, Info0, Info).
:- pred remove_file(module_name::in, string::in, make_info::in, make_info::out,
		io__state::di, io__state::uo) is det.

:- pred remove_file(file_name::in, make_info::in, make_info::out,
		io__state::di, io__state::uo) is det.

%-----------------------------------------------------------------------------%

:- func make_target_list(list(K), V) = assoc_list(K, V).

:- func make_dependency_list(list(module_name), module_target_type) =
		list(dependency_file).

:- func target_extension(globals, module_target_type) = maybe(string).
:- mode target_extension(in, in) = out is det.
:- mode target_extension(in, out) = in(bound(yes(ground))) is nondet.

:- pred linked_target_file_name(module_name, linked_target_type, file_name,
		io__state, io__state).
:- mode linked_target_file_name(in, in, out, di, uo) is det.

	% Find the extension for the timestamp file for the
	% given target type, if one exists.
:- func timestamp_extension(globals, module_target_type) = string is semidet.

:- pred target_is_grade_or_arch_dependent(module_target_type::in) is semidet.

%-----------------------------------------------------------------------------%
	% Debugging, verbose and error messages.

	% Apply the given predicate if `--debug-make' is set.
:- pred debug_msg(pred(io__state, io__state)::(pred(di, uo) is det),
		io__state::di, io__state::uo) is det.

	% Apply the given predicate if `--verbose-make' is set.
:- pred verbose_msg(pred(io__state, io__state)::(pred(di, uo) is det),
		io__state::di, io__state::uo) is det.

	% Write a debugging message relating to a given target file.
:- pred debug_file_msg(target_file::in, string::in,
		io__state::di, io__state::uo) is det.

:- pred write_dependency_file(dependency_file::in,
		io__state::di, io__state::uo) is det.

:- pred write_target_file(target_file::in,
		io__state::di, io__state::uo) is det.

	% Write a message "Making <filename>" if `--verbose-make' is set.
:- pred maybe_make_linked_target_message(file_name::in,
		io__state::di, io__state::uo) is det.

	% Write a message "Making <filename>" if `--verbose-make' is set.
:- pred maybe_make_target_message(target_file::in,
		io__state::di, io__state::uo) is det.

:- pred maybe_make_target_message(io__output_stream::in, target_file::in,
		io__state::di, io__state::uo) is det.

	% Write a message "** Error making <filename>".
:- pred target_file_error(target_file::in,
		io__state::di, io__state::uo) is det.

	% Write a message "** Error making <filename>".
:- pred file_error(file_name::in, io__state::di, io__state::uo) is det.

	% If the given target was specified on the command
	% line, warn that it was already up to date.
:- pred maybe_warn_up_to_date_target(pair(module_name, target_type)::in,
	make_info::in, make_info::out, io__state::di, io__state::uo) is det.

%-----------------------------------------------------------------------------%

:- implementation.

foldl2_maybe_stop_at_error(KeepGoing, MakeTarget,
		Targets, Success, Info0, Info) -->
	foldl2_maybe_stop_at_error_2(KeepGoing, MakeTarget, Targets,
		yes, Success, Info0, Info).

:- pred foldl2_maybe_stop_at_error_2(bool::in,
	foldl2_pred_with_status(T, Info, IO)::in(foldl2_pred_with_status),
	list(T)::in, bool::in, bool::out, Info::in, Info::out,
	IO::di, IO::uo) is det.

foldl2_maybe_stop_at_error_2(_KeepGoing, _P, [],
		Success, Success, Info, Info) --> [].
foldl2_maybe_stop_at_error_2(KeepGoing, P, [T | Ts],
		Success0, Success, Info0, Info) -->
	P(T, Success1, Info0, Info1),
	( { Success1 = yes ; KeepGoing = yes } ->
		foldl2_maybe_stop_at_error_2(KeepGoing, P, Ts,
			Success0 `and` Success1, Success, Info1, Info)
	;
		{ Success = no },
		{ Info = Info0 }
	).

foldl3_maybe_stop_at_error(KeepGoing, P, Ts, Success,
		Acc0, Acc, Info0, Info) -->
	foldl3_maybe_stop_at_error_2(KeepGoing, P, Ts,
		yes, Success, Acc0, Acc, Info0, Info).

:- pred foldl3_maybe_stop_at_error_2(bool::in,
	foldl3_pred_with_status(T, Acc, Info, IO)::in(foldl3_pred_with_status),
	list(T)::in, bool::in, bool::out, Acc::in, Acc::out,
	Info::in, Info::out, IO::di, IO::uo) is det.

foldl3_maybe_stop_at_error_2(_KeepGoing, _P, [],
		Success, Success, Acc, Acc, Info, Info) --> [].
foldl3_maybe_stop_at_error_2(KeepGoing, P, [T | Ts],
		Success0, Success, Acc0, Acc, Info0, Info) -->
	P(T, Success1, Acc0, Acc1, Info0, Info1),
	( { Success1 = yes ; KeepGoing = yes } ->
		foldl3_maybe_stop_at_error_2(KeepGoing, P, Ts,
			Success0 `and` Success1, Success, Acc1, Acc,
			Info1, Info)
	;
		{ Success = no },
		{ Acc = Acc0 },
		{ Info = Info0 }
	).

%-----------------------------------------------------------------------------%

build_with_module_options_and_output_redirect(ModuleName,
		ExtraOptions, Build, Succeeded, Info0, Info) -->	
    build_with_module_options(ModuleName, ExtraOptions,
	(pred(AllOptions::in, Succeeded1::out,
			Info1::in, Info2::out, di, uo) is det -->
	    build_with_output_redirect(ModuleName,
		(pred(ErrorStream::in, Succeeded2::out,
				Info3::in, Info4::out, di, uo) is det -->
		    Build(AllOptions, ErrorStream, Succeeded2, Info3, Info4)
		), Succeeded1, Info1, Info2)
	), Succeeded, Info0, Info).

build_with_output_redirect(ModuleName, Build, Succeeded, Info0, Info) -->
	redirect_output(ModuleName, RedirectResult, Info0, Info1),
	(
		{ RedirectResult = no },
		{ Succeeded = no },
		{ Info = Info1 }
	;
		{ RedirectResult = yes(ErrorStream) },
		Build(ErrorStream, Succeeded, Info1, Info2),
		unredirect_output(ModuleName, ErrorStream, Info2, Info)
	).

build_with_module_options(ModuleName, ExtraOptions,
		Build, Succeeded, Info0, Info) -->
	build_with_module_options(yes, ModuleName, Info0 ^ options_variables,
		Info0 ^ option_args, ExtraOptions, Build, Succeeded,
		Info0, Info).

build_with_module_options(ModuleName, OptionVariables,
		OptionArgs, ExtraOptions, Build, Succeeded, Info0, Info) -->
	build_with_module_options(no, ModuleName, OptionVariables,
		OptionArgs, ExtraOptions, Build, Succeeded, Info0, Info).

:- pred build_with_module_options(bool::in, module_name::in,
	options_variables::in, list(string)::in, list(string)::in,
	build(list(string), Info)::in(build),
	bool::out, Info::in, Info::out, io__state::di, io__state::uo) is det.

build_with_module_options(InvokedByMmcMake, ModuleName, OptionVariables,
		OptionArgs, ExtraOptions, Build, Succeeded, Info0, Info) -->
	lookup_mmc_module_options(OptionVariables, ModuleName, OptionsResult),
	(
		{ OptionsResult = no },
		{ Info = Info0 },
		{ Succeeded = no }
	;
		{ OptionsResult = yes(ModuleOptionArgs) }, 
		globals__io_get_globals(Globals),

		% --invoked-by-mmc-make disables reading DEFAULT_MCFLAGS
		% from the environment (DEFAULT_MCFLAGS is included in
		% OptionArgs) and generation of `.d' files.
		% --use-subdirs is needed because the code to install
		% libraries uses `--use-grade-subdirs' and assumes the
		% interface files were built with `--use-subdirs'.
		{ InvokedByMmcMake = yes ->
			UseSubdirs = ["--use-subdirs"],
			InvokedByMake = ["--invoked-by-mmc-make"]
		;
			UseSubdirs = [],
			InvokedByMake = []
		},

		{ AllOptionArgs = list__condense([InvokedByMake,
			ModuleOptionArgs, OptionArgs,
			ExtraOptions, UseSubdirs]) },
		handle_options(AllOptionArgs, OptionsError, _, _, _),
		(
			{ OptionsError = yes(OptionsMessage) },
			{ Succeeded = no },
			{ Info = Info0 },
			usage_error(OptionsMessage)
		;
			{ OptionsError = no },
			Build(AllOptionArgs, Succeeded, Info0, Info),
			globals__io_set_globals(unsafe_promise_unique(Globals))
		)
	).

redirect_output(_ModuleName, MaybeErrorStream, Info, Info) -->
	%
	% Write the output to a temporary file first, so it's
	% easy to just print the part of the error file
	% that relates to the current command. It will
	% be appended to the error file later.
	%
	io__make_temp(ErrorFileName),
	io__open_output(ErrorFileName, ErrorFileRes),
	(
		{ ErrorFileRes = ok(ErrorOutputStream) },
		{ MaybeErrorStream = yes(ErrorOutputStream) }
	;
		{ ErrorFileRes = error(IOError) },
		{ MaybeErrorStream = no },
		io__write_string("** Error opening `"),
		io__write_string(ErrorFileName),
		io__write_string("' for output: "),
		{ io__error_message(IOError, Msg) },
		io__write_string(Msg),
		io__nl
	).

unredirect_output(ModuleName, ErrorOutputStream, Info0, Info) -->
   io__output_stream_name(ErrorOutputStream, TmpErrorFileName),
   io__close_output(ErrorOutputStream),

   io__open_input(TmpErrorFileName, TmpErrorInputRes),
   (
	{ TmpErrorInputRes = ok(TmpErrorInputStream) },
	module_name_to_file_name(ModuleName, ".err", yes, ErrorFileName),
	( { set__member(ModuleName, Info0 ^ error_file_modules) } -> 
		io__open_append(ErrorFileName, ErrorFileRes)
	;
		io__open_output(ErrorFileName, ErrorFileRes)
	),
	( 
	    { ErrorFileRes = ok(ErrorFileOutputStream) },
	    globals__io_lookup_int_option(output_compile_error_lines,
			LinesToWrite),
	    io__output_stream(CurrentOutputStream),
	    io__input_stream_foldl2_io(TmpErrorInputStream,
	    		write_error_char(ErrorFileOutputStream,
	    		CurrentOutputStream, LinesToWrite),
			0, TmpFileInputRes),
	    (
	    	{ TmpFileInputRes = ok(_) }
	    ;
		{ TmpFileInputRes = error(_, TmpFileInputError) },
		io__write_string("Error reading `"),
		io__write_string(TmpErrorFileName),
		io__write_string("': "),
		io__write_string(io__error_message(TmpFileInputError)),
		io__nl
	    ),

	    io__close_output(ErrorFileOutputStream),

	    { Info = Info0 ^ error_file_modules :=
			set__insert(Info0 ^ error_file_modules, ModuleName) }
	;
	    { ErrorFileRes = error(Error) },
	    { Info = Info0 },
	    io__write_string("Error opening `"),
	    io__write_string(TmpErrorFileName),
	    io__write_string("': "),
	    io__write_string(io__error_message(Error)),
	    io__nl
	),
	io__close_input(TmpErrorInputStream)
    ;
	{ TmpErrorInputRes = error(Error) },
	{ Info = Info0 },
	io__write_string("Error opening `"),
	io__write_string(TmpErrorFileName),
	io__write_string("': "),
	io__write_string(io__error_message(Error)),
	io__nl
    ),
    io__remove_file(TmpErrorFileName, _).

:- pred write_error_char(io__output_stream::in, io__output_stream::in,
		int::in, char::in, int::in, int::out,
		io__state::di, io__state::uo) is det.

write_error_char(FullOutputStream, PartialOutputStream, LineLimit,
		Char, Lines0, Lines) -->
	io__write_char(FullOutputStream, Char),
	( { Lines0 < LineLimit } ->
		io__write_char(PartialOutputStream, Char)
	;
		[]
	),
	{ Lines = ( Char = '\n' -> Lines0 + 1 ; Lines0 ) }.

%-----------------------------------------------------------------------------%

get_timestamp_file_timestamp(ModuleName - FileType,
		MaybeTimestamp, Info0, Info) -->
	globals__io_get_globals(Globals),
	( { TimestampExt = timestamp_extension(Globals, FileType) } ->
		module_name_to_file_name(ModuleName,
			TimestampExt, no, FileName)
	;
		module_target_to_file_name(ModuleName, FileType, no, FileName)
	),

	% We should only ever look for timestamp files
	% in the current directory. Timestamp files are
	% only used when processing a module, and only
	% modules in the current directory are processed.
	{ SearchDirs = [dir__this_directory] },
	get_file_timestamp(SearchDirs, FileName, MaybeTimestamp, Info0, Info).

get_dependency_timestamp(file(FileName, MaybeOption), MaybeTimestamp,
			Info0, Info) -->
	(       
		{ MaybeOption = yes(Option) },
		globals__io_lookup_accumulating_option(Option, SearchDirs)
	;       
		{ MaybeOption = no },
		{ SearchDirs = [dir__this_directory] }
	),
	get_file_timestamp(SearchDirs, FileName, MaybeTimestamp, Info0, Info).
get_dependency_timestamp(target(Target), MaybeTimestamp, Info0, Info) -->
	get_target_timestamp(yes, Target, MaybeTimestamp0, Info0, Info),
	{ Target = _ - c_header(mih), MaybeTimestamp0 = ok(_) ->
		% Don't rebuild the `.o' file if an irrelevant part of a
		% `.mih' file has changed. If a relevant part of a `.mih'
		% file changed, the interface files of the imported module
		% must have changed in a way that would force the `.c' and
		% `.o' files of the current module to be rebuilt.
		MaybeTimestamp = ok(oldest_timestamp)	
	;
		MaybeTimestamp = MaybeTimestamp0
	}.

get_target_timestamp(Search, ModuleName - FileType, MaybeTimestamp,
		Info0, Info) -->
	get_file_name(Search, ModuleName - FileType, FileName, Info0, Info1),
	( { Search = yes } ->
		get_search_directories(FileType, SearchDirs)
	;
		{ SearchDirs = [dir__this_directory] }
	),
	get_file_timestamp(SearchDirs, FileName, MaybeTimestamp0,
		Info1, Info2),
	(
		{ MaybeTimestamp0 = error(_) },
		{ FileType = intermodule_interface }
	->
		%
		% If a `.opt' file in another directory doesn't exist,
		% it just means that a library wasn't compiled with
		% `--intermodule-optimization'.
		%
		get_module_dependencies(ModuleName, MaybeImports,	
			Info2, Info3),
		{
			MaybeImports = yes(Imports),
			Imports ^ module_dir \= dir__this_directory
		->
			MaybeTimestamp = ok(oldest_timestamp),
			Info = Info3 ^ file_timestamps
					^ elem(FileName) := MaybeTimestamp
		;
			MaybeTimestamp = MaybeTimestamp0,
			Info = Info3
		}
	;
		{ MaybeTimestamp = MaybeTimestamp0 },
		{ Info = Info2 }
	).

get_file_name(Search, ModuleName - FileType, FileName, Info0, Info) -->
	( { FileType = source } -> 
		%
		% In some cases the module name won't match the file
		% name (module mdb.parse might be in parse.m or mdb.m),
		% so we need to look up the file name here.
		% 
		get_module_dependencies(ModuleName, MaybeImports, Info0, Info),
		(
			{ MaybeImports = yes(Imports) },
			{ FileName = Imports ^ source_file_name }
		;
			{ MaybeImports = no },

			% Something has gone wrong generating the dependencies,
			% so just take a punt (which probably won't work).
			module_name_to_file_name(ModuleName, ".m",
				no, FileName)
		)
	;
		{ Info = Info0 },
		globals__io_get_globals(Globals),
		{ MaybeExt = target_extension(Globals, FileType) },
		(
			{ MaybeExt = yes(Ext) },
			( { Search = yes } ->
				module_name_to_search_file_name(ModuleName,
					Ext, FileName)
			;
				module_name_to_file_name(ModuleName,
					Ext, no, FileName)
			)
		;
			{ MaybeExt = no },
			module_target_to_file_name(ModuleName, FileType,
				no, Search, FileName)
		)
	).

get_file_timestamp(SearchDirs, FileName, MaybeTimestamp, Info0, Info) -->
	( { MaybeTimestamp0 = Info0 ^ file_timestamps ^ elem(FileName) } -> 
		{ Info = Info0 },
		{ MaybeTimestamp = MaybeTimestamp0 }
	;
		io__input_stream(OldInputStream),
		search_for_file(SearchDirs, FileName, SearchResult),
		( { SearchResult = ok(_) } ->
			io__input_stream_name(FullFileName),
			io__set_input_stream(OldInputStream, FileStream),
			io__close_input(FileStream),
			io__file_modification_time(FullFileName, TimeTResult),
			{
				TimeTResult = ok(TimeT),
				Timestamp = time_t_to_timestamp(TimeT),
				MaybeTimestamp = ok(Timestamp)
			;
				TimeTResult = error(Error),
				MaybeTimestamp = error(
						io__error_message(Error))
			},
			{ Info = Info0 ^ file_timestamps
					^ elem(FileName) := MaybeTimestamp }
		;
			{ MaybeTimestamp = error("file `" ++ FileName
							++ "' not found") },
			{ Info = Info0 }
		)
	).

:- pred get_search_directories(module_target_type::in, list(dir_name)::out,
		io__state::di, io__state::uo) is det.	

get_search_directories(FileType, SearchDirs) -->
	( { yes(SearchDirOpt) = search_for_file_type(FileType) } ->
		globals__io_lookup_accumulating_option(SearchDirOpt,
			SearchDirs0),
		% Make sure the current directory is searched
		% for C headers and libraries.
		{ SearchDirs =
			( list__member(dir__this_directory, SearchDirs0) -> 
				SearchDirs0
			;
				[dir__this_directory | SearchDirs0]
			) }
	;
		{ SearchDirs = [dir__this_directory] }
	).

find_oldest_timestamp(error(_) @ Timestamp, _) = Timestamp.
find_oldest_timestamp(ok(_), error(_) @ Timestamp) = Timestamp.
find_oldest_timestamp(ok(Timestamp1), ok(Timestamp2)) =
    ok( ( compare((<), Timestamp1, Timestamp2) -> Timestamp1 ; Timestamp2 ) ).

%-----------------------------------------------------------------------------%

remove_target_file(ModuleName - FileType, Info0, Info) -->
	remove_target_file(ModuleName, FileType, Info0, Info).

remove_target_file(ModuleName, FileType, Info0, Info) -->
	globals__io_get_globals(Globals),
	module_target_to_file_name(ModuleName, FileType, no, FileName),
	remove_file(FileName, Info0, Info1),
	( { TimestampExt = timestamp_extension(Globals, FileType) } ->
		remove_file(ModuleName, TimestampExt, Info1, Info)
	;
		{ Info = Info1 }
	).

remove_file(ModuleName, Ext, Info0, Info) -->
	module_name_to_file_name(ModuleName, Ext, no, FileName),
	remove_file(FileName, Info0, Info).

remove_file(FileName, Info0, Info) -->
	io__remove_file(FileName, _),
	{ Info = Info0 ^ file_timestamps :=
			map__delete(Info0 ^ file_timestamps, FileName) }.

%-----------------------------------------------------------------------------%

make_target_list(Ks, V) = list__map((func(K) = K - V), Ks).

make_dependency_list(ModuleNames, FileType) =
	list__map((func(Module) = target(Module - FileType)), ModuleNames).

target_extension(_, source) = yes(".m").
target_extension(_, errors) = yes(".err").
target_extension(_, private_interface) = yes(".int0").
target_extension(_, long_interface) = yes(".int").
target_extension(_, short_interface) = yes(".int2").
target_extension(_, unqualified_short_interface) = yes(".int3").
target_extension(_, intermodule_interface) = yes(".opt").
target_extension(_, aditi_code) = yes(".rlo").
target_extension(_, c_header(mih)) = yes(".mih").
target_extension(_, c_header(mh)) = yes(".mh").
target_extension(_, c_code) = yes(".c").
target_extension(_, il_code) = yes(".il").

	% XXX ".exe" if the module contains main.
target_extension(_, il_asm) = yes(".dll").
target_extension(_, java_code) = yes(".java").
target_extension(_, asm_code(non_pic)) = yes(".s").
target_extension(_, asm_code(link_with_pic)) = yes(".s").
target_extension(_, asm_code(pic)) = yes(".pic_s").
target_extension(Globals, object_code(PIC)) = yes(Ext) :-
	maybe_pic_object_file_extension(Globals, PIC, Ext).

	% These all need to be handled as special cases.
target_extension(_, foreign_object(_, _)) = no.
target_extension(_, foreign_il_asm(_)) = no.
target_extension(_, fact_table_object(_, _)) = no.

linked_target_file_name(ModuleName, executable, FileName) -->
	globals__io_lookup_string_option(executable_file_extension, Ext),
	module_name_to_file_name(ModuleName, Ext, no, FileName).
linked_target_file_name(ModuleName, static_library, FileName) -->
	globals__io_lookup_string_option(library_extension, Ext),
	module_name_to_lib_file_name("lib", ModuleName, Ext, no, FileName).
linked_target_file_name(ModuleName, shared_library, FileName) -->
	globals__io_lookup_string_option(shared_library_extension, Ext),
	module_name_to_lib_file_name("lib", ModuleName, Ext, no, FileName).

:- pred module_target_to_file_name(module_name::in, module_target_type::in,
		bool::in, file_name::out, io__state::di, io__state::uo) is det.

module_target_to_file_name(ModuleName, TargetType, MkDir, FileName) -->
	module_target_to_file_name(ModuleName, TargetType,
		MkDir, no, FileName).

:- pred module_target_to_search_file_name(module_name::in,
		module_target_type::in, file_name::out,
		io__state::di, io__state::uo) is det.

module_target_to_search_file_name(ModuleName, TargetType, FileName) -->
	module_target_to_file_name(ModuleName, TargetType, no, yes, FileName).

:- pred module_target_to_file_name(module_name::in, module_target_type::in,
		bool::in, bool::in, file_name::out,
		io__state::di, io__state::uo) is det.

module_target_to_file_name(ModuleName, TargetType, MkDir, Search, FileName) -->
    globals__io_get_globals(Globals),
    { target_extension(Globals, TargetType) = MaybeExt },
    (
	{ MaybeExt = yes(Ext) },
	( { Search = yes } ->
		module_name_to_search_file_name(ModuleName,
			Ext, FileName)
	;		
		module_name_to_file_name(ModuleName,
			Ext, MkDir, FileName)
	)
    ;
	{ MaybeExt = no },
	( { TargetType = foreign_object(PIC, Lang) } ->
		(
			{ ForeignModuleName = foreign_language_module_name(
					ModuleName, Lang) }
		->
			module_target_to_file_name(ForeignModuleName,
				object_code(PIC), MkDir, Search, FileName)
		;
			{ error("module_target_to_file_name_2") }
		)
	; { TargetType = foreign_il_asm(Lang) } ->
		(
			{ ForeignModuleName = foreign_language_module_name(
					ModuleName, Lang) }
		->
			module_target_to_file_name(ForeignModuleName,
				il_asm, MkDir, Search, FileName)
		;
			{ error("module_target_to_file_name_2") }
		)
	; { TargetType = fact_table_object(PIC, FactFile) } ->
		maybe_pic_object_file_extension(PIC, Ext),
		fact_table_file_name(ModuleName, FactFile, Ext,
			MkDir, FileName)
	;
		{ error("module_target_to_file_name_2") }
	)
    ).


	% Note that we need a timestamp file for `.err' files because
	% errors are written to the `.err' file even when writing interfaces.
	% The timestamp is only updated when compiling to target code.
timestamp_extension(_, errors) = ".err_date".
timestamp_extension(_, private_interface) = ".date0".
timestamp_extension(_, long_interface) = ".date".
timestamp_extension(_, short_interface) = ".date".
timestamp_extension(_, unqualified_short_interface) = ".date3".
timestamp_extension(_, intermodule_interface) = ".optdate".
timestamp_extension(_, c_code) = ".c_date".
timestamp_extension(Globals, c_header(_)) = Ext :-
	globals__get_target(Globals, Target),
	Ext = timestamp_extension(Globals,
			(Target = asm -> asm_code(non_pic) ; c_code)).
timestamp_extension(_, il_code) = ".il_date".
timestamp_extension(_, java_code) = ".java_date".
timestamp_extension(_, asm_code(non_pic)) = ".s_date".
timestamp_extension(_, asm_code(pic)) = ".pic_s_date".

:- func search_for_file_type(module_target_type) = maybe(option).

search_for_file_type(source) = no.
search_for_file_type(errors) = no.
	% XXX only for inter-module optimization.
search_for_file_type(private_interface) = yes(search_directories).
search_for_file_type(long_interface) = yes(search_directories).
search_for_file_type(short_interface) = yes(search_directories).
search_for_file_type(unqualified_short_interface) = yes(search_directories).
search_for_file_type(intermodule_interface) = yes(intermod_directories).
search_for_file_type(aditi_code) = no.
search_for_file_type(c_header(_)) = yes(c_include_directory).
search_for_file_type(c_code) = no.
search_for_file_type(il_code) = no.
search_for_file_type(il_asm) = no.
search_for_file_type(java_code) = no.
search_for_file_type(asm_code(_)) = no.
search_for_file_type(object_code(_)) = no.
search_for_file_type(foreign_object(_, _)) = no.
search_for_file_type(foreign_il_asm(_)) = no.
search_for_file_type(fact_table_object(_, _)) = no.

target_is_grade_or_arch_dependent(Target) :-
	target_is_grade_or_arch_dependent(Target, yes).

:- pred target_is_grade_or_arch_dependent(module_target_type::in,
		bool::out) is det.

target_is_grade_or_arch_dependent(source, no).
target_is_grade_or_arch_dependent(errors, no).
target_is_grade_or_arch_dependent(private_interface, no).
target_is_grade_or_arch_dependent(long_interface, no).
target_is_grade_or_arch_dependent(short_interface, no).
target_is_grade_or_arch_dependent(unqualified_short_interface, no).
target_is_grade_or_arch_dependent(intermodule_interface, yes).
target_is_grade_or_arch_dependent(aditi_code, no).
target_is_grade_or_arch_dependent(c_header(mh), no).
target_is_grade_or_arch_dependent(c_header(mih), yes).
target_is_grade_or_arch_dependent(c_code, yes).
target_is_grade_or_arch_dependent(il_code, yes).
target_is_grade_or_arch_dependent(il_asm, yes).
target_is_grade_or_arch_dependent(java_code, yes).
target_is_grade_or_arch_dependent(asm_code(_), yes).
target_is_grade_or_arch_dependent(object_code(_), yes).
target_is_grade_or_arch_dependent(foreign_object(_, _), yes).
target_is_grade_or_arch_dependent(foreign_il_asm(_), yes).
target_is_grade_or_arch_dependent(fact_table_object(_, _), yes).

%-----------------------------------------------------------------------------%

debug_msg(P) -->
	globals__io_lookup_bool_option(debug_make, Debug),
	( { Debug = yes } ->
		P,
		io__flush_output
	;
		[]
	).

verbose_msg(P) -->
	globals__io_lookup_bool_option(verbose_make, Verbose),
	( { Verbose = yes } ->
		P,
		io__flush_output
	;
		[]
	).

debug_file_msg(TargetFile, Msg) -->
	debug_msg(
		(pred(di, uo) is det -->
			write_target_file(TargetFile),
			io__write_string(": "),
			io__write_string(Msg),
			io__nl
		)).

write_dependency_file(target(TargetFile)) --> write_target_file(TargetFile).
write_dependency_file(file(FileName, _)) --> io__write_string(FileName).

write_target_file(ModuleName - FileType) -->
	module_target_to_file_name(ModuleName, FileType, no, FileName),
	io__write_string(FileName).

maybe_make_linked_target_message(TargetFile) -->
	verbose_msg(
		(pred(di, uo) is det -->
			io__write_string("Making "),
			io__write_string(TargetFile),
			io__nl
		)).

maybe_make_target_message(TargetFile) -->
	io__output_stream(OutputStream),
	maybe_make_target_message(OutputStream, TargetFile).

maybe_make_target_message(OutputStream, TargetFile) -->
	verbose_msg(
		(pred(di, uo) is det -->
			io__set_output_stream(OutputStream, OldOutputStream),
			io__write_string("Making "),
			write_target_file(TargetFile),
			io__nl,
			io__set_output_stream(OldOutputStream, _)
		)).

target_file_error(TargetFile) -->
	io__write_string("** Error making `"),
	write_target_file(TargetFile),
	io__write_string("'.\n").

file_error(TargetFile) -->
	io__write_string("** Error making `"),
	io__write_string(TargetFile),
	io__write_string("'.\n").

maybe_warn_up_to_date_target(Target @ (ModuleName - FileType), Info0, Info) -->
	globals__io_lookup_bool_option(warn_up_to_date, Warn),
	( { Warn = yes } ->
		( { set__member(Target, Info0 ^ command_line_targets) } ->
			io__write_string("** Nothing to be done for `"),
			(
				{ FileType = module_target(ModuleTargetType) },
				write_target_file(ModuleName - ModuleTargetType)
			;
				{ FileType = linked_target(LinkedTargetType) },
				linked_target_file_name(ModuleName,
					LinkedTargetType, FileName),
				io__write_string(FileName)
			;
				{ FileType = misc_target(_) },
				{ error(
			"maybe_warn_up_to_date_target: misc_target") }
			),
			io__write_string("'.\n")
		;
			[]
		)
	;
		[]
	),
	{ Info = Info0 ^ command_line_targets :=
		set__delete(Info0 ^ command_line_targets, Target) }.

%-----------------------------------------------------------------------------%

:- func this_file = string.
this_file = "make.util.m".

%-----------------------------------------------------------------------------%