project(
    'zinnia',
    license: 'ISC',
    version: '0.1.0',
    meson_version: '>=1.5.0',
    default_options: [
        'c_std=gnu23',
        'werror=true',
        'warning_level=2',
        'strip=true',
    ],
)

if get_option('headers_only')
    install_subdir('include/uapi', install_dir: get_option('includedir'))
    pkg = import('pkgconfig')
    pkg.generate(name: 'zinnia', description: 'Zinnia user API')
    subdir_done()
endif

add_languages('c', native: false, required: true)

# Check if we're using a sane compiler.
c_compiler = meson.get_compiler('c')

# We require a compiler that supports the GNU C dialect.
assert(c_compiler.has_define('__GNUC__'))

if get_option('tools_only')
    subdir('tools')
    subdir_done()
endif

add_project_arguments(
    '-Wno-unused',
    '-Wno-unused-parameter',
    language: 'c',
)

common_c_args = [
    '-fno-stack-protector',
    '-fno-omit-frame-pointer',
    '-ffunction-sections',
    '-fdata-sections',
    '-ffreestanding',
    '-nostdinc',
]

common_link_args = [
    '-ffreestanding',
    '-nostdlib',
    '-Wl,-z,noexecstack',
    '-Wl,--gc-sections',
    '-Wl,--build-id=none',
]

common_includes = [
    include_directories('include'),
    include_directories('arch' / target_machine.cpu_family() / 'include'),
]

cfg = configuration_data()
cfg.set_quoted('ZINNIA_VERSION', meson.project_version())
cfg.set_quoted('ZINNIA_ARCH', target_machine.cpu_family())
cfg.set_quoted('ZINNIA_COMPILER_ID', c_compiler.get_id() + ' ' + c_compiler.version())
cfg.set_quoted('ZINNIA_LINKER_ID', c_compiler.get_linker_id())

# Parse kernel config
kv = import('keyval')
kconfig = kv.load(get_option('config_path'))
foreach k, v : kconfig
    if v == 'y'
        cfg.set10(k, true)
    elif v == 'n'
        cfg.set10(k, false)
    else
        cfg.set(k, v)
    endif
endforeach

kernel_c_args = ['-D__IN_KERNEL']

kernel_lds = meson.current_source_dir() / 'boot' / 'kernel.ld'
kernel_link_args = [
    '-T' + kernel_lds,
    '-shared',
    '-Wl,-Bsymbolic',
    '-Wl,-soname,zinnia',
]

kernel_includes = []
kernel_sources = []
modules = {}

# These dirs go first so we can add arch-specific flags to drivers.
subdir('arch' / target_machine.cpu_family())
subdir('boot')
subdir('core')
subdir('syscalls')

# Device and file system drivers.
subdir('dev')
subdir('fs')

configure_file(
    configuration: cfg,
    output: 'config.h',
)

zinnia_datadir = get_option('datadir') / 'zinnia'

mod_summary = {}
modular_modules = {}
builtin_libs = []

foreach name, v : modules
    foreach dep : v.get('depends', [])
        assert(
            dep in modules,
            'Module "' + name + '" depends on unknown module "' + dep + '"',
        )
        assert(
            not modules[dep].get('modular', false),
            'Module "'
            + name
            + '" can\'t depend on modular module "'
            + dep
            + '"',
        )
    endforeach

    if v.get('modular', false)
        modular_modules += {name: v}
        mod_summary += {name: 'module'}
        continue
    endif

    mod_c_args = v.get('c_args', [])
    mod_includes = v.get('include_directories', [])
    builtin_libs += static_library(
        name,
        sources: v.get('sources'),
        c_args: [
            common_c_args,
            kernel_c_args,
            mod_c_args,
            '-D__MODULE_NAME="' + name + '"',
        ],
        include_directories: [common_includes, kernel_includes, mod_includes],
        pic: true,
    )
    kernel_c_args += mod_c_args
    kernel_includes += mod_includes
    kernel_link_args += v.get('link_args', [])
    mod_summary += {name: 'builtin'}
endforeach

# Kernel
kernel = executable(
    'zinnia',
    include_directories: [
        common_includes,
        kernel_includes,
    ],
    c_args: [common_c_args, kernel_c_args],
    link_args: [common_link_args, kernel_link_args],
    link_depends: kernel_lds,
    sources: kernel_sources,
    link_whole: builtin_libs,
    pie: true,
    install: true,
    install_dir: zinnia_datadir,
)

foreach name, v : modular_modules
    shared_library(
        name,
        sources: v.get('sources'),
        c_args: [
            common_c_args,
            '-fPIC',
            '-D__IN_MODULE',
            '-D__MODULE_NAME="' + name + '"',
            v.get('c_args', []),
        ],
        link_args: [
            common_link_args,
            '-T' + module_lds, kernel.full_path(),
            v.get('link_args', []),
        ],
        link_depends: [module_lds, kernel],
        include_directories: [
            common_includes,
            kernel_includes, # We want this, actually
            v.get('include_directories', []),
        ],
        name_prefix: '',
        name_suffix: 'kso',
        link_with: v.get('link_with', []),
        install_dir: zinnia_datadir / 'modules',
    )
endforeach

# Print a summary
summary(mod_summary, section: 'Driver configuration')
summary(kconfig, bool_yn: true, section: 'Kernel configuration')