# TODO: Use vcs_tag() to generate version string
# TODO: jobfile
# TODO: lto
# TODO: CONFIG_BUILD_SHARED_LIBS
# TODO: fix clang build

project(
    'HelenOS',
    [ 'c', 'cpp' ],
    default_options : ['buildtype=plain', 'c_std=gnu11', 'cpp_std=c++17', 'warning_level=3', 'werror=false', 'b_staticpic=false', 'default_library=shared', 'prefix=/' ],
)

cc = meson.get_compiler('c')
basename = find_program('basename')
dirname = find_program('dirname')
find = find_program('find')
grep = find_program('grep')
mkarray = find_program('tools/mkarray_for_meson.sh')
objdump = find_program('objdump')
sed = find_program('sed')
unzip = find_program('unzip')
which = find_program('which')

autocheck = generator(find_program('tools/autocheck.awk'),
	arguments: [ '@INPUT@' ],
	output: '@PLAINNAME@.check.c',
	capture: true,
)


if get_option('default_library') == 'both'
	error('You must use either shared or static for default_library.')
endif

debug_options = false

# Output compiler flags for use by third-party builds.
# NOTE: See $srcroot/meson/cross/$arch for architecture-specific compiler flags.

if debug_options
	message('Cross c_args:')
	message(meson.get_cross_property('c_args'))
	message('Cross cpp_args:')
	message(meson.get_cross_property('cpp_args'))
	message('Cross c_link_args:')
	message(meson.get_cross_property('c_link_args'))
	message('Cross cpp_link_args:')
	message(meson.get_cross_property('cpp_link_args'))
endif

# Read some variables from Makefile.common
config_variables = [
	# Uspace and kernel
	'CONFIG_BAREBONE',
	'CONFIG_BUILD_SHARED_LIBS',
	'CONFIG_DEBUG',
	'CONFIG_DEVEL_FILES',
	'CONFIG_FPU',
	'CONFIG_LINE_DEBUG',
	'CONFIG_PCUT_SELF_TESTS',
	'CONFIG_PCUT_TESTS',
	'CONFIG_RTLD',
	'CONFIG_STRIP_BINARIES',
	'CONFIG_UBSAN',
	'CONFIG_USE_SHARED_LIBS',
	'CROSS_TARGET',
	'OPTIMIZATION',
	'PROCESSOR',
	'QUADFLOAT',
	'RDFMT',

	# Kernel only
	'CONFIG_ACPI',
	'CONFIG_AM335X_TIMERS',
	'CONFIG_ASID',
	'CONFIG_ASID_FIFO',
	'CONFIG_AT_KBD',
	'CONFIG_BCM2835_MAILBOX',
	'CONFIG_DSRLNIN',
	'CONFIG_DSRLNOUT',
	'CONFIG_EGA',
	'CONFIG_FB',
	'CONFIG_GICV2',
	'CONFIG_I8042',
	'CONFIG_I8259',
	'CONFIG_IOMAP_BITMAP',
	'CONFIG_IOMAP_DUMMY',
	'CONFIG_KCONSOLE',
	'CONFIG_MAC_KBD',
	'CONFIG_MULTIBOOT',
	'CONFIG_NS16550',
	'CONFIG_OFW_PCI',
	'CONFIG_OFW_TREE',
	'CONFIG_OMAP_UART',
	'CONFIG_PAGE_HT',
	'CONFIG_PAGE_PT',
	'CONFIG_PC_KBD',
	'CONFIG_PL011_UART',
	'CONFIG_PL050',
	'CONFIG_S3C24XX_IRQC',
	'CONFIG_S3C24XX_UART',
	'CONFIG_SMP',
	'CONFIG_SOFTINT',
	'CONFIG_SRLN',
	'CONFIG_SUN_KBD',
	'CONFIG_SYMTAB',
	'CONFIG_TEST',
	'CONFIG_TRACE',
	'CONFIG_TSB',
	'CONFIG_UDEBUG',
	'CONFIG_VIA_CUDA',
	'MACHINE',
	'MEMORY_MODEL',

	'UARCH',
	'KARCH',
]

foreach varname : config_variables
	result = run_command(grep, '^' + varname + '\\b', meson.source_root() / 'Makefile.config')
	if result.returncode() != 0
		# TODO: Output negative/inapplicable variables too in config, so that we can check for typos here.
		#warning('Missing configuration variable ' + varname + ' in Makefile.config')
		set_variable(varname, false)
		continue
	endif

	value = result.stdout().split('\n')[0].strip().split('=')[1].strip()
	if value == 'y'
		value = true
	elif value == 'n'
		value = false
	endif

	set_variable(varname, value)
	if debug_options
		message([ varname, value ])
	endif
endforeach

# Also read version information.
version_variables = [
	'COPYRIGHT',
	'NAME',
	'PATCHLEVEL',
	'SUBLEVEL',
	'VERSION',
]

foreach varname : version_variables
	line = run_command(grep, '^' + varname + '\\b', meson.source_root() / 'version', check: true).stdout().strip()
	value = line.split('=')[1].strip()
	set_variable('HELENOS_' + varname, value)
	if debug_options
		message([ 'HELENOS_' + varname, value ])
	endif
endforeach

HELENOS_RELEASE = HELENOS_VERSION + '.' + HELENOS_PATCHLEVEL + '.' + HELENOS_SUBLEVEL


meson.add_install_script('install.sh', CONFIG_DEVEL_FILES.to_string())

add_project_arguments(
	# TODO: Remove from project arguments and only use where needed.
	'-imacros', join_paths(meson.source_root(), 'config.h'),
	language : [ 'c' ],
)

add_project_link_arguments(
	cc.get_supported_link_arguments([
		'-Wl,--gc-sections',
		'-Wl,--warn-common',
	]),
	'-Wl,--fatal-warnings',
	language : [ 'c', 'cpp' ],
)

# TODO: enable more warnings
# FIXME: -fno-builtin-strftime works around seemingly spurious format warning.
# We should investigate what's going on there.

extra_common_flags = [
	'-O' + OPTIMIZATION,
	'-fexec-charset=UTF-8',
	'-finput-charset=UTF-8',

	'-D_HELENOS_SOURCE',
	'-Wa,--fatal-warnings',

	'-Wall',
	'-Wextra',

	'-Werror-implicit-function-declaration',

	'-Wwrite-strings',
	'-Wsystem-headers',
	'-Wunknown-pragmas',

	'-Wno-unused-parameter',

	'-pipe',
	'-ffunction-sections',

	'-fno-common',

	'-fdebug-prefix-map=' + meson.source_root() + '=.',
]

if UARCH != 'ia64'
	extra_common_flags += [ '-fvar-tracking-assignments' ]
endif

if CONFIG_DEBUG
	extra_common_flags += [ '-Werror' ]
endif

if CONFIG_LINE_DEBUG
	extra_common_flags += [ '-gdwarf-4', '-g3' ]
endif

extra_cflags = extra_common_flags + [
	'-Wmissing-prototypes',

	'-Wno-missing-braces',
	'-Wno-missing-field-initializers',
	'-Wno-unused-command-line-argument',
	'-Wno-unused-parameter',
	'-Wno-typedef-redefinition',
	'-Wno-clobbered',
	'-Wno-nonnull-compare',

	'-fno-builtin-strftime',
]

if CONFIG_UBSAN
	extra_cflags += '-fsanitize=undefined'
endif

extra_cppflags = extra_common_flags + [
	'-fno-exceptions',
	'-frtti',
]

w_flags = {
	'c': extra_cflags,
	'cpp': extra_cppflags,
}

# Process flags. Only sets those that compiler supports.
foreach lang : [ 'c', 'cpp' ]
	extra_cflags = meson.get_compiler(lang).get_supported_arguments(w_flags.get(lang))
	add_project_arguments(extra_cflags, language : [ lang ])
	add_project_link_arguments(extra_cflags, language : [ lang ])
endforeach

# Init binaries.
rd_init = [
	'app/init',
	'srv/bd/rd',
	'srv/fs/' + RDFMT,
	'srv/loader',
	'srv/locsrv',
	'srv/logger',
	'srv/ns',
	'srv/vfs',
]

# Binaries allowed on the initrd image when CONFIG_BAREBONE is enabled.
rd_essential = rd_init + [
	'app/bdsh',
	'app/getterm',
	'app/kio',

	'srv/devman',
	'srv/fs/locfs',
	'srv/hid/console',
	'srv/hid/input',
	'srv/hid/output',
	'srv/klog',

	'drv/root/root',
	'drv/root/virt',
	'drv/fb/kfb',
]

if CONFIG_FB
	rd_essential += [
		'app/vlaunch',
		'app/vterm',

		'srv/hid/compositor',
	]
endif


## The at-sign
#
# The `atsign` variable holds the ASCII character representing the at-sign
# ('@') used in various $(AS) constructs (e.g. @progbits). On architectures that
# don't use '@' for starting a comment, `atsign` is merely '@'. However, on
# those that do use it for starting a comment (e.g. arm32), `atsign` must be
# defined as the percentile-sign ('%') in the architecture-dependent files.
#
atsign = '@'

## Some architectures need a particular string at the beginning of assembly files.
kernel_as_prolog = ''
uspace_as_prolog = ''

subdir('meson' / 'arch' / UARCH)

subdir('kernel')
subdir('uspace')


## Generate config.mk

# Get the directory where the compiler resides.

cc_fullname = run_command(which, meson.get_compiler('c').cmd_array()[0].split(' ')[0], check: true).stdout().strip()
cc_path = run_command(dirname, cc_fullname, check: true).stdout().strip()

message(['Compiler directory is:', cc_path])

export_cppflags = [
	'-isystem', '$(HELENOS_EXPORT_ROOT)/include/posix',
	'-isystem', '$(HELENOS_EXPORT_ROOT)/include/libc',
	'-idirafter', '$(HELENOS_EXPORT_ROOT)/include',
]

export_ldflags = [
	'-nostdlib',
	'-L$(HELENOS_EXPORT_ROOT)/lib',
	'-Wl,--whole-archive',
	'$(HELENOS_EXPORT_ROOT)/lib/libstartfiles.a',
	'-Wl,--no-whole-archive',
]

export_ldlibs = [
	'-Wl,--as-needed',
	'-lposix',
	'-lmath',
	'-lc',
	'-lgcc',
	'-Wl,--no-as-needed',
]

cc_arch = meson.get_cross_property('cc_arch')

conf_data = configuration_data({
	'HELENOS_CROSS_PATH' : cc_path,
	'HELENOS_ARCH' : cc_arch,
	'HELENOS_CFLAGS' : ' '.join(arch_uspace_c_args),
	'HELENOS_CXXFLAGS' : ' '.join(arch_uspace_c_args),
	'HELENOS_CPPFLAGS' : ' '.join(export_cppflags),
	'HELENOS_LDFLAGS' : ' '.join(export_ldflags),
	'HELENOS_LDLIBS' : ' '.join(export_ldlibs),
	'HELENOS_TARGET' : cc_arch + '-helenos',
})

config_mk = configure_file(
	input: 'config.mk.in',
	output: 'config.mk',
	configuration: conf_data,
	install: true,
	install_dir: 'config',
)

custom_target('config.sh',
	input: config_mk,
	output: 'config.sh',
	command: [ sed, 's:$(HELENOS_EXPORT_ROOT):${HELENOS_EXPORT_ROOT}:g', '@INPUT@' ],
	capture: true,
	install: true,
	install_dir: 'config',
)

install_data('Makefile.common', 'Makefile.config', install_dir: 'config')