load("@bazel_skylib//rules:write_file.bzl", "write_file")
load("@rules_cc//cc:cc_binary.bzl", "cc_binary")
load("@rules_cc//cc:cc_library.bzl", "cc_library")
load("@rules_cc_autoconf//autoconf:autoconf.bzl", "autoconf")
load("@rules_cc_autoconf//autoconf:autoconf_hdr.bzl", "autoconf_hdr")
load("@rules_cc_autoconf//autoconf:autoconf_srcs.bzl", "autoconf_srcs")
load("@rules_cc_autoconf//autoconf:checks.bzl", "checks")
load("@rules_cc_autoconf//autoconf:package_info.bzl", "package_info")

LOCAL_DEFINES = [
    "HAVE_CONFIG_H",
] + select({
    "@platforms//os:macos": [
        "_DARWIN_C_SOURCE",
    ],
    "//conditions:default": [],
})

GENERATED_SRCS = {
    "lib/alloca.h": "lib/alloca.in.h",
    "lib/fcntl.h": "lib/fcntl.in.h",
    "lib/getopt-cdefs.h": "lib/getopt-cdefs.in.h",
    "lib/getopt.h": "lib/getopt.in.h",
    "lib/iconv.h": "lib/iconv.in.h",
    "lib/inttypes.h": "lib/inttypes.in.h",
    "lib/limits.h": "lib/limits.in.h",
    "lib/locale.h": "lib/locale.in.h",
    "lib/malloc/scratch_buffer.gl.h": "lib/malloc/scratch_buffer.h",
    "lib/math.h": "lib/math.in.h",
    "lib/sched.h": "lib/sched.in.h",
    "lib/signal.h": "lib/signal.in.h",
    "lib/spawn.h": "lib/spawn.in.h",
    "lib/stdalign.h": "lib/stdalign.in.h",
    "lib/stddef.h": "lib/stddef.in.h",
    "lib/stdint.h": "lib/stdint.in.h",
    "lib/stdio.h": "lib/stdio.in.h",
    "lib/stdlib.h": "lib/stdlib.in.h",
    "lib/string.h": "lib/string.in.h",
    "lib/strings.h": "lib/strings.in.h",
    "lib/sys/ioctl.h": "lib/sys_ioctl.in.h",
    "lib/sys/resource.h": "lib/sys_resource.in.h",
    "lib/sys/stat.h": "lib/sys_stat.in.h",
    "lib/sys/time.h": "lib/sys_time.in.h",
    "lib/sys/times.h": "lib/sys_times.in.h",
    "lib/sys/types.h": "lib/sys_types.in.h",
    "lib/sys/wait.h": "lib/sys_wait.in.h",
    "lib/termios.h": "lib/termios.in.h",
    "lib/textstyle.h": "lib/textstyle.in.h",
    "lib/time.h": "lib/time.in.h",
    "lib/unistd.h": "lib/unistd.in.h",
    "lib/unistr.h": "lib/unistr.in.h",
    "lib/unitypes.h": "lib/unitypes.in.h",
    "lib/uniwidth.h": "lib/uniwidth.in.h",
    "lib/wchar.h": "lib/wchar.in.h",
    "lib/wctype.h": "lib/wctype.in.h",
}

BISON_UNIQUE_M4_FILES = [
    "m4/bison-check-compiler-flag.m4",
    "m4/bison-cxx-std.m4",
    "m4/c-working.m4",
    "m4/cxx.m4",
    "m4/flex.m4",
    "m4/gnulib-comp.m4",
    "m4/m4.m4",
    "m4/printf-posix-rpl.m4",
    "m4/wchar_t.m4",
    "m4/year2038.m4",
]

# Gnulib m4 modules used by bison (from m4/gnulib-comp.m4)
# Note: 00gnulib is required for proper template processing
GNULIB_M4_DEPS = [
    "@rules_cc_autoconf//gnulib/m4/{}".format(file[len("m4/"):-len(".m4")])
    for file in glob(
        include = ["m4/*.m4"],
        exclude = BISON_UNIQUE_M4_FILES,
    )
]

# Package information from configure.ac
package_info(
    name = "bison_package_info",
    package_name = "GNU Bison",
    aliases = {
        "VERSION": "PACKAGE_VERSION",
    },
    module_bazel = "MODULE.bazel",
    package_bugreport = "bug-bison@gnu.org",
    package_url = "https://www.gnu.org/software/bison/",
    strip_bcr_version = True,
)

autoconf(
    name = "m4_bison-check-compiler-flag",
    checks = [],
)

autoconf(
    name = "m4_bison-cxx-std",
    checks = [
        # BISON_CXXSTD from m4/bison-cxx-std.m4 (configure.ac lines 77-83)
        # Tests compiler flags and AC_SUBSTs CXX<STD>_CXXFLAGS
        # In Bazel, C++ standard is set via toolchain, but we provide flags for Makefile compatibility
        checks.AC_SUBST("CXX98_CXXFLAGS", "-std=c++98"),
        checks.AC_SUBST("CXX03_CXXFLAGS", "-std=c++03"),
        checks.AC_SUBST("CXX11_CXXFLAGS", "-std=c++11"),
        checks.AC_SUBST("CXX14_CXXFLAGS", "-std=c++14"),
        checks.AC_SUBST("CXX17_CXXFLAGS", "-std=c++17"),
        checks.AC_SUBST("CXX20_CXXFLAGS", "-std=c++20"),
        checks.AC_SUBST("CXX2B_CXXFLAGS", "-std=c++2b"),
    ],
)

# Checks from m4/c-working.m4
# BISON_TEST_FOR_WORKING_C_COMPILER - line 233
# BISON_C_COMPILER_POSIXLY_CORRECT - line 234
autoconf(
    name = "m4_c-working",
    checks = [
        # BISON_TEST_FOR_WORKING_C_COMPILER
        # Test that C compiler can compile a simple program
        # AC_SUBST BISON_C_WORKS to ":" (colon means true in shell)
        checks.AC_SUBST("BISON_C_WORKS", ":"),
        # BISON_C_COMPILER_POSIXLY_CORRECT
        # Check if C compiler supports -g in POSIXLY_CORRECT mode
        # AC_SUBST C_COMPILER_POSIXLY_CORRECT to "true" or "false"
        checks.AC_SUBST("C_COMPILER_POSIXLY_CORRECT", "true"),
    ],
)

# Checks from m4/cxx.m4
# BISON_TEST_FOR_WORKING_CXX_COMPILER - line 235
# BISON_CXX_COMPILER_POSIXLY_CORRECT - line 236
autoconf(
    name = "m4_cxx",
    checks = [
        # BISON_TEST_FOR_WORKING_CXX_COMPILER
        # Test that C++ compiler can compile and link a simple program
        # AC_SUBST BISON_CXX_WORKS to ":" (if works), "false" (if doesn't), or ":" (if cross-compiling)
        checks.AC_SUBST("BISON_CXX_WORKS", ":"),
        # BISON_CXX_COMPILER_POSIXLY_CORRECT
        # Check if C++ compiler supports -g in POSIXLY_CORRECT mode
        # AC_SUBST CXX_COMPILER_POSIXLY_CORRECT to "true" or "false"
        checks.AC_SUBST("CXX_COMPILER_POSIXLY_CORRECT", "true"),
    ],
)

# Note: m4_bison_cxx_std checks are now in m4_bison-cxx-std (the canonical target name)

# Checks from m4/flex.m4
# AC_PROG_LEX - line 258
autoconf(
    name = "m4_flex",
    checks = [
        # Look for flex or lex program
        # AC_SUBST LEX - path to lex/flex program
        checks.AC_SUBST("LEX", "flex"),
        # AC_SUBST LEX_IS_FLEX - true or false
        checks.AC_SUBST("LEX_IS_FLEX", "true"),
        # AC_SUBST FLEX_SUPPORTS_HEADER_OPT - true or false
        checks.AC_SUBST("FLEX_SUPPORTS_HEADER_OPT", "true"),
        # AC_SUBST LEX_OUTPUT_ROOT - lex.yy or lexyy
        checks.AC_SUBST("LEX_OUTPUT_ROOT", "lex.yy"),
        # AC_SUBST LEXLIB - -lfl, -ll, or empty
        checks.AC_SUBST("LEXLIB", ""),
        # AC_DEFINE YYTEXT_POINTER if yytext is a pointer
        checks.AC_DEFINE("YYTEXT_POINTER", "1"),
    ],
)

autoconf(
    name = "m4_gnulib-comp",
    checks = [
        checks.AC_DEFINE(
            "GNULIB_XALLOC",
            1,
            subst = True,
        ),
        checks.AC_DEFINE(
            "GNULIB_XALLOC_DIE",
            1,
            subst = True,
        ),
        checks.AC_DEFINE(
            "GNULIB_STDIO_SINGLE_THREAD",
            1,
            subst = True,
        ),
        checks.AC_DEFINE(
            "USE_UNLOCKED_IO",
            "GNULIB_STDIO_SINGLE_THREAD",
        ),
        # ======================================================================
        # Module indicators from gnulib-comp.m4
        # These override the defaults (0) set by upstream header modules to
        # activate gnulib module functionality in generated replacement headers.
        # ======================================================================

        # --- gl_MODULE_INDICATOR (AC_DEFINE in config.h) ---
        checks.AC_DEFINE("GNULIB_CANONICALIZE", 1),
        checks.AC_DEFINE("GNULIB_CANONICALIZE_LGPL", 1),
        checks.AC_DEFINE("GNULIB_CLOEXEC", 1),
        checks.AC_DEFINE("GNULIB_CLOSE_STREAM", 1),
        checks.AC_DEFINE("GNULIB_DIRNAME", 1),
        checks.AC_DEFINE("GNULIB_FD_SAFER_FLAG", 1),
        checks.AC_DEFINE("GNULIB_FOPEN_GNU", 1),
        checks.AC_DEFINE("GNULIB_FOPEN_SAFER", 1),
        checks.AC_DEFINE("GNULIB_GETCWD", 1),
        checks.AC_DEFINE("GNULIB_LOCK", 1),
        checks.AC_DEFINE("GNULIB_MSVC_NOTHROW", 1),
        checks.AC_DEFINE("GNULIB_OPENAT", 1),
        checks.AC_DEFINE("GNULIB_PIPE2_SAFER", 1),
        checks.AC_DEFINE("GNULIB_REALLOCARRAY", 1),
        checks.AC_DEFINE("GNULIB_SNPRINTF", 1),
        checks.AC_DEFINE("GNULIB_STRERROR", 1),
        checks.AC_DEFINE("GNULIB_STRERROR_R_POSIX", 1),
        checks.AC_DEFINE("GNULIB_UNISTR_U8_MBTOUCR", 1),
        checks.AC_DEFINE("GNULIB_UNISTR_U8_UCTOMB", 1),
        checks.AC_DEFINE("GNULIB_FSCANF", 1),
        checks.AC_DEFINE("GNULIB_SCANF", 1),
        checks.AC_DEFINE("GNULIB_VFPRINTF_POSIX", 1),
        checks.AC_DEFINE("GNULIB_FDOPENDIR", 1),

        # --- gl_STDIO_MODULE_INDICATOR (AC_SUBST for stdio.in.h) ---
        checks.AC_SUBST("GNULIB_FOPEN", 1),
        checks.AC_SUBST("GNULIB_FPRINTF", 1),
        checks.AC_SUBST("GNULIB_FPRINTF_POSIX", 1),
        checks.AC_SUBST("GNULIB_FGETC", 1),
        checks.AC_SUBST("GNULIB_FGETS", 1),
        checks.AC_SUBST("GNULIB_FPUTC", 1),
        checks.AC_SUBST("GNULIB_FPUTS", 1),
        checks.AC_SUBST("GNULIB_FREAD", 1),
        checks.AC_SUBST("GNULIB_FSCANF", 1),
        checks.AC_SUBST("GNULIB_FWRITE", 1),
        checks.AC_SUBST("GNULIB_GETC", 1),
        checks.AC_SUBST("GNULIB_GETCHAR", 1),
        checks.AC_SUBST("GNULIB_GETDELIM", 1),
        checks.AC_SUBST("GNULIB_GETLINE", 1),
        checks.AC_SUBST("GNULIB_OBSTACK_PRINTF", 1),
        checks.AC_SUBST("GNULIB_PERROR", 1),
        checks.AC_SUBST("GNULIB_PRINTF", 1),
        checks.AC_SUBST("GNULIB_PRINTF_POSIX", 1),
        checks.AC_SUBST("GNULIB_PUTC", 1),
        checks.AC_SUBST("GNULIB_PUTCHAR", 1),
        checks.AC_SUBST("GNULIB_PUTS", 1),
        checks.AC_SUBST("GNULIB_RENAME", 1),
        checks.AC_SUBST("GNULIB_SCANF", 1),
        checks.AC_SUBST("GNULIB_SNPRINTF", 1),
        checks.AC_SUBST("GNULIB_SPRINTF_POSIX", 1),
        checks.AC_SUBST("GNULIB_VASPRINTF", 1),
        checks.AC_SUBST("GNULIB_VFPRINTF", 1),
        checks.AC_SUBST("GNULIB_VFPRINTF_POSIX", 1),
        checks.AC_SUBST("GNULIB_VPRINTF", 1),
        checks.AC_SUBST("GNULIB_VSNPRINTF", 1),
        checks.AC_SUBST("GNULIB_VSPRINTF_POSIX", 1),

        # --- gl_UNISTD_MODULE_INDICATOR (AC_SUBST for unistd.in.h) ---
        # Note: GNULIB_ACCESS omitted because bison 3.8.2's lib/access.c is
        # Windows-only, but upstream rules_cc_autoconf sets REPLACE_ACCESS=1
        # on macOS (for newer gnulib). Leaving GNULIB_ACCESS=0 prevents the
        # rpl_access redirect while keeping system access() available.
        checks.AC_SUBST("GNULIB_CHDIR", 1),
        checks.AC_SUBST("GNULIB_CLOSE", 1),
        checks.AC_SUBST("GNULIB_DUP2", 1),
        checks.AC_SUBST("GNULIB_ENVIRON", 1),
        checks.AC_SUBST("GNULIB_FCHDIR", 1),
        checks.AC_SUBST("GNULIB_FSYNC", 1),
        checks.AC_SUBST("GNULIB_GETCWD", 1),
        checks.AC_SUBST("GNULIB_GETDTABLESIZE", 1),
        checks.AC_SUBST("GNULIB_GETOPT_POSIX", 1),
        checks.AC_SUBST("GNULIB_PIPE", 1),
        checks.AC_SUBST("GNULIB_PIPE2", 1),
        checks.AC_SUBST("GNULIB_READLINK", 1),
        checks.AC_SUBST("GNULIB_RMDIR", 1),
        checks.AC_SUBST("GNULIB_UNLINK", 1),
        checks.AC_SUBST("GNULIB_UNISTD_H_GETOPT", 1),

        # --- gl_STDLIB_MODULE_INDICATOR (AC_SUBST for stdlib.in.h) ---
        checks.AC_SUBST("GNULIB_CALLOC_POSIX", 1),
        checks.AC_SUBST("GNULIB_CANONICALIZE_FILE_NAME", 1),
        checks.AC_SUBST("GNULIB_FREE_POSIX", 1),
        checks.AC_SUBST("GNULIB_MALLOC_POSIX", 1),
        checks.AC_SUBST("GNULIB_REALLOCARRAY", 1),
        checks.AC_SUBST("GNULIB_REALLOC_POSIX", 1),
        checks.AC_SUBST("GNULIB_REALPATH", 1),
        checks.AC_SUBST("GNULIB_STRTOD", 1),
        checks.AC_SUBST("GNULIB_UNSETENV", 1),

        # --- gl_STRING_MODULE_INDICATOR (AC_SUBST for string.in.h) ---
        checks.AC_SUBST("GNULIB_FFSL", 1),
        checks.AC_SUBST("GNULIB_MEMCHR", 1),
        checks.AC_SUBST("GNULIB_MEMPCPY", 1),
        checks.AC_SUBST("GNULIB_MEMRCHR", 1),
        checks.AC_SUBST("GNULIB_RAWMEMCHR", 1),
        checks.AC_SUBST("GNULIB_STPCPY", 1),
        checks.AC_SUBST("GNULIB_STPNCPY", 1),
        checks.AC_SUBST("GNULIB_STRCHRNUL", 1),
        checks.AC_SUBST("GNULIB_STRDUP", 1),
        checks.AC_SUBST("GNULIB_STRERROR", 1),
        checks.AC_SUBST("GNULIB_STRERROR_R", 1),
        checks.AC_SUBST("GNULIB_STRNDUP", 1),
        checks.AC_SUBST("GNULIB_STRNLEN", 1),
        checks.AC_SUBST("GNULIB_STRVERSCMP", 1),

        # --- gl_MATH_MODULE_INDICATOR (AC_SUBST for math.in.h) ---
        checks.AC_SUBST("GNULIB_FREXP", 1),
        checks.AC_SUBST("GNULIB_FREXPL", 1),
        checks.AC_SUBST("GNULIB_ISNAN", 1),
        checks.AC_SUBST("GNULIB_ISNAND", 1),
        checks.AC_SUBST("GNULIB_ISNANF", 1),
        checks.AC_SUBST("GNULIB_ISNANL", 1),
        checks.AC_SUBST("GNULIB_LDEXPL", 1),
        checks.AC_SUBST("GNULIB_SIGNBIT", 1),

        # --- gl_WCHAR_MODULE_INDICATOR (AC_SUBST for wchar.in.h) ---
        checks.AC_SUBST("GNULIB_MBRTOWC", 1),
        checks.AC_SUBST("GNULIB_MBSINIT", 1),
        checks.AC_SUBST("GNULIB_WCWIDTH", 1),

        # --- gl_WCTYPE_MODULE_INDICATOR (AC_SUBST for wctype.in.h) ---
        checks.AC_SUBST("GNULIB_ISWBLANK", 1),
        checks.AC_SUBST("GNULIB_ISWDIGIT", 1),
        checks.AC_SUBST("GNULIB_ISWXDIGIT", 1),

        # --- gl_SPAWN_MODULE_INDICATOR (AC_SUBST for spawn.in.h) ---
        checks.AC_SUBST("GNULIB_POSIX_SPAWN", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDCHDIR", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDCLOSE", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDDUP2", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWN_FILE_ACTIONS_ADDOPEN", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWN_FILE_ACTIONS_DESTROY", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWN_FILE_ACTIONS_INIT", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWNATTR_DESTROY", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWNATTR_INIT", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWNATTR_SETFLAGS", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWNATTR_SETPGROUP", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWNATTR_SETSIGMASK", 1),
        checks.AC_SUBST("GNULIB_POSIX_SPAWNP", 1),

        # --- gl_SIGNAL_MODULE_INDICATOR (AC_SUBST for signal.in.h) ---
        checks.AC_SUBST("GNULIB_RAISE", 1),
        checks.AC_SUBST("GNULIB_SIGACTION", 1),
        checks.AC_SUBST("GNULIB_SIGPROCMASK", 1),

        # --- gl_SYS_STAT_MODULE_INDICATOR (AC_SUBST for sys_stat.in.h) ---
        checks.AC_SUBST("GNULIB_FSTAT", 1),
        checks.AC_SUBST("GNULIB_FSTATAT", 1),
        checks.AC_SUBST("GNULIB_LSTAT", 1),
        checks.AC_SUBST("GNULIB_STAT", 1),

        # --- gl_SYS_TIME_MODULE_INDICATOR (AC_SUBST for sys_time.in.h) ---
        checks.AC_SUBST("GNULIB_GETTIMEOFDAY", 1),

        # --- gl_SYS_RESOURCE_MODULE_INDICATOR ---
        checks.AC_SUBST("GNULIB_GETRUSAGE", 1),

        # --- gl_SYS_WAIT_MODULE_INDICATOR (AC_SUBST for sys_wait.in.h) ---
        checks.AC_SUBST("GNULIB_WAITPID", 1),

        # --- gl_FCNTL_MODULE_INDICATOR (AC_SUBST for fcntl.in.h) ---
        checks.AC_SUBST("GNULIB_FCNTL", 1),
        checks.AC_SUBST("GNULIB_OPEN", 1),
        checks.AC_SUBST("GNULIB_OPENAT", 1),

        # --- gl_ICONV_MODULE_INDICATOR ---
        checks.AC_SUBST("GNULIB_ICONV", 1),

        # --- gl_DIRENT_MODULE_INDICATOR ---
        checks.AC_SUBST("GNULIB_CLOSEDIR", 1),
        checks.AC_SUBST("GNULIB_DIRFD", 1),
        checks.AC_SUBST("GNULIB_FDOPENDIR", 1),
        checks.AC_SUBST("GNULIB_OPENDIR", 1),
        checks.AC_SUBST("GNULIB_READDIR", 1),
        checks.AC_SUBST("GNULIB_REWINDDIR", 1),

        # --- gl_LOCALE_MODULE_INDICATOR ---
        checks.AC_SUBST("GNULIB_SETLOCALE_NULL", 1),

        # --- gl_STRINGS_MODULE_INDICATOR ---
        checks.AC_SUBST("GNULIB_FFS", 1),

        # ======================================================================
        # Compatibility substitutions for older gnulib variable names used by
        # bison 3.8.2 templates (newer gnulib uses _FOR_*_POSIX suffixed names)
        # ======================================================================
        checks.AC_SUBST("REPLACE_CALLOC", 0),
        checks.AC_SUBST("REPLACE_MALLOC", 0),
        checks.AC_SUBST("REPLACE_REALLOC", 0),
    ],
)

# Checks from m4/m4.m4
# AC_PROG_GNU_M4 - line 268
autoconf(
    name = "m4_m4",
    checks = [
        # Look for GNU M4 1.4.6 or later
        # AC_SUBST M4 - path to m4 program (used in Makefiles)
        checks.AC_SUBST("M4", "m4"),
        # AC_SUBST M4_GNU - --gnu or empty (used in Makefiles)
        checks.AC_SUBST("M4_GNU", "--gnu"),
        # AC_SUBST M4_DEBUGFILE - --debugfile or --error-output (used in Makefiles)
        checks.AC_SUBST("M4_DEBUGFILE", "--debugfile"),
        # AC_DEFINE_UNQUOTED M4_GNU_OPTION (configure.ac line 270-271)
        # Note: M4 itself is AC_DEFINE_UNQUOTED in configure.ac, but we use AC_SUBST for Makefile compatibility
        checks.AC_DEFINE("M4_GNU_OPTION", '"--gnu"'),
    ],
)

# Checks from m4/printf-posix-rpl.m4
# gl_FUNC_PRINTF_POSIX - may be called via gnulib modules
autoconf(
    name = "m4_printf-posix-rpl",
    checks = [
        # Check if printf needs POSIX replacement
        # AC_SUBST REPLACE_PRINTF - 0 or 1
        checks.AC_SUBST("REPLACE_PRINTF", "0"),
        # AC_DEFINE REPLACE_PRINTF_POSIX - 0 or 1
        checks.AC_DEFINE("REPLACE_PRINTF_POSIX", "0"),
    ],
)

# Checks from m4/wchar_t.m4
# gt_TYPE_WCHAR_T - may be called via gnulib
autoconf(
    name = "m4_wchar_t",
    checks = [
        # Check if <stddef.h> has the wchar_t type
        # AC_DEFINE HAVE_WCHAR_T - 1 if found (for C preprocessor)
        checks.AC_DEFINE("HAVE_WCHAR_T", "1"),
        # AC_SUBST for stddef.in.h template (@HAVE_WCHAR_T@ substitution)
        checks.AC_SUBST("HAVE_WCHAR_T", 1),
    ],
)

# Checks from m4/year2038.m4
# gl_YEAR2038_EARLY and gl_YEAR2038_BODY - may be called via gnulib
autoconf(
    name = "m4_year2038",
    checks = [
        # Check for time_t past year 2038 support
        # On mingw, AC_DEFINE __MINGW_USE_VC2005_COMPAT
        # For 32-bit systems, may need _TIME_BITS=64 and _FILE_OFFSET_BITS=64
        # Most 64-bit systems already have 64-bit time_t, so these are typically not needed
        # AC_DEFINE _TIME_BITS and _FILE_OFFSET_BITS if needed (left empty for most systems)
    ] + select({
        "@platforms//os:windows": [
            checks.AC_DEFINE("__MINGW_USE_VC2005_COMPAT", "1"),
        ],
        "//conditions:default": [],
    }),
)

BISON_UNIQUE_AUTOCONF_TARGETS = [
    # Strip `m4/` prefix and `.m4` suffix.
    "m4_{}".format(file[3:-3])
    for file in BISON_UNIQUE_M4_FILES
]

# Standard autoconf checks from configure.ac
# AC_CHECK_HEADERS_ONCE([locale.h]) - line 278
# AC_C_INLINE - line 281
# AC_CHECK_FUNCS_ONCE([setlocale]) - line 288
autoconf(
    name = "configure_ac",
    checks = [
        # checks.AC_C_INLINE(),
        checks.AC_CHECK_FUNC("setlocale"),
        checks.AC_SUBST("GUARD_PREFIX", "GL"),
        checks.AC_SUBST("GNULIB_LOCALENAME", 0),
        checks.AC_DEFINE("M4", '"/usr/bin/m4"'),
        checks.AC_DEFINE("PACKAGE_COPYRIGHT_YEAR", 2026),

        # Checks from m4/bison-i18n.m4 (BISON_I18N - configure.ac line 295)
        # Internationalization support (simplified - assumes no NLS for cross-platform build)
        checks.AC_DEFINE("YYENABLE_NLS", "0"),
        checks.AC_SUBST("BISON_USE_NLS", "no"),
        checks.AC_SUBST("BISON_LOCALEDIR", ""),

        # =================================================================
        # Gnulib conditional source compilation gates (COMPILE_* variables)
        # These determine which replacement sources to compile based on
        # function availability. COMPILE_*=1 means the function is MISSING
        # and the gnulib replacement should be compiled.
        # =================================================================

        # rawmemchr — GNU extension, missing on macOS
        checks.AC_TRY_LINK(
            name = "bison_cv_func_rawmemchr",
            code = """\
#define _GNU_SOURCE 1
#include <string.h>
int main(void) { (void)rawmemchr; return 0; }
""",
        ),
        checks.AC_SUBST(
            "COMPILE_RAWMEMCHR",
            condition = "!bison_cv_func_rawmemchr",
        ),
        checks.AC_SUBST(
            "COMPILE_MEMPCPY",
            condition = "!ac_cv_func_mempcpy",
        ),
        checks.AC_SUBST("COMPILE_REALLOCARRAY", "1"),
        checks.AC_TRY_LINK(
            name = "bison_cv_func_strverscmp",
            code = """\
#include <string.h>
int main(void) { return strverscmp("1.0", "2.0"); }
""",
        ),
        checks.AC_SUBST(
            "COMPILE_STRVERSCMP",
            condition = "!bison_cv_func_strverscmp",
        ),
        checks.AC_TRY_LINK(
            name = "bison_cv_func_canonicalize_file_name",
            code = """\
#ifdef __cplusplus
extern "C"
#endif
char *canonicalize_file_name(const char *);
int main(void) { return canonicalize_file_name(".") != 0; }
""",
        ),
        checks.AC_SUBST(
            "COMPILE_CANONICALIZE_LGPL",
            condition = "!bison_cv_func_canonicalize_file_name",
        ),

        # error.c — compiled when error_at_line() is missing (macOS)
        checks.AC_CHECK_FUNC("error_at_line"),
        checks.AC_SUBST(
            "COMPILE_ERROR",
            condition = "!ac_cv_func_error_at_line",
        ),

        # fpending.c — compiled when __fpending() is missing (macOS)
        checks.AC_TRY_LINK(
            name = "bison_cv_func___fpending",
            code = """\
#include <stdio.h>
#if HAVE_STDIO_EXT_H
# include <stdio_ext.h>
#endif
int main(void) { return ! __fpending(stdin); }
""",
        ),
        checks.AC_SUBST(
            "COMPILE_FPENDING",
            condition = "!bison_cv_func___fpending",
        ),

        # fseterr.c — compiled when __fseterr() is missing (macOS)
        checks.AC_TRY_LINK(
            name = "bison_cv_func___fseterr",
            code = """\
#include <stdio.h>
#ifdef __cplusplus
extern "C"
#endif
void __fseterr(FILE *);
int main(void) { __fseterr(stdin); return 0; }
""",
        ),
        checks.AC_SUBST(
            "COMPILE_FSETERR",
            condition = "!bison_cv_func___fseterr",
        ),
        checks.AC_SUBST("COMPILE_OBSTACK_PRINTF", "1"),
    ] + select({
        "@platforms//os:linux": [
            # getopt: __GETOPT_PREFIX=rpl_ always set → replacement always needed
            checks.AC_SUBST("COMPILE_GETOPT", "1"),
            checks.AC_SUBST("COMPILE_OPEN", "0"),
            checks.AC_SUBST("COMPILE_UNLINK", "0"),
            checks.AC_SUBST("COMPILE_STRERROR_OVERRIDE", "0"),
            checks.AC_SUBST("COMPILE_MBRTOWC", "1"),
            checks.AC_SUBST("COMPILE_SPAWN_FACTION_ADDCHDIR", "1"),
        ],
        "@platforms//os:macos": [
            checks.AC_SUBST("COMPILE_GETOPT", "1"),
            checks.AC_SUBST("COMPILE_OPEN", "1"),
            checks.AC_SUBST("COMPILE_UNLINK", "1"),
            checks.AC_SUBST("COMPILE_STRERROR_OVERRIDE", "1"),
            checks.AC_SUBST("COMPILE_MBRTOWC", "0"),
            checks.AC_SUBST("COMPILE_SPAWN_FACTION_ADDCHDIR", "1"),
        ],
        "@platforms//os:windows": [
            checks.AC_SUBST("COMPILE_GETOPT", "1"),
            checks.AC_SUBST("COMPILE_OPEN", "0"),
            checks.AC_SUBST("COMPILE_UNLINK", "0"),
            checks.AC_SUBST("COMPILE_STRERROR_OVERRIDE", "0"),
            checks.AC_SUBST("COMPILE_MBRTOWC", "0"),
            checks.AC_SUBST("COMPILE_SPAWN_FACTION_ADDCHDIR", "1"),
            # Override string_h toolchain defaults for POSIX functions missing
            # on Windows.  Without these the generated string.h skips their
            # declarations, causing implicit-int errors on MSVC.
            checks.AC_SUBST("HAVE_STPCPY", 0),
            checks.AC_SUBST("HAVE_STPNCPY", 0),
        ],
        "//conditions:default": [
            checks.AC_SUBST("COMPILE_GETOPT", "1"),
            checks.AC_SUBST("COMPILE_OPEN", "0"),
            checks.AC_SUBST("COMPILE_UNLINK", "0"),
            checks.AC_SUBST("COMPILE_STRERROR_OVERRIDE", "0"),
            checks.AC_SUBST("COMPILE_MBRTOWC", "0"),
            checks.AC_SUBST("COMPILE_SPAWN_FACTION_ADDCHDIR", "1"),
        ],
    }),
    deps = [
        ":bison_package_info",
    ] + BISON_UNIQUE_AUTOCONF_TARGETS + GNULIB_M4_DEPS,
)

# Generate header files from templates using autoconf_hdr
# These templates contain @PLACEHOLDER@ markers that need to be processed
[
    autoconf_hdr(
        name = hdr[:-len(".h")] + "_h",
        out = hdr,
        defaults = True,
        inlines = {
            "/* The definition of _GL_ARG_NONNULL is copied here.  */": "lib/arg-nonnull.h",
            "/* The definition of _GL_WARN_ON_USE is copied here.  */": "lib/warn-on-use.h",
            "/* The definitions of _GL_FUNCDECL_RPL etc. are copied here.  */": "lib/c++defs.h",
        },
        mode = "subst",
        substitutions = {
            "libc_hidden_proto": "// libc_hidden_proto",
            "__always_inline": "inline _GL_ATTRIBUTE_ALWAYS_INLINE",
            "__glibc_likely": "_GL_LIKELY",
            "__glibc_unlikely": "_GL_UNLIKELY",
        },
        template = template,
        deps = [":configure_ac"],
    )
    for hdr, template in GENERATED_SRCS.items()
]

autoconf_hdr(
    name = "lib/config_h",
    out = "lib/config.h",
    template = "lib/config.in.h",
    deps = [":configure_ac"],
)

write_file(
    name = "configmake_h_src",
    out = "lib/configmake.h",
    content = [
        "#define LOCALEDIR \"\"",
        "#define PKGDATADIR \"bison/data\"",
        "",
    ],
    newline = "unix",
    tags = ["manual"],
)

BISON_COPTS = select({
    "@rules_cc//cc/compiler:clang": [
        "-w",
        "-std=c11",
        "-Wno-unused-but-set-variable",
    ],
    "@rules_cc//cc/compiler:gcc": [
        "-w",
        "-std=c11",
    ],
    "@rules_cc//cc/compiler:msvc-cl": [
        # C4116: unnamed type definition in parentheses
        "/wd4116",
    ],
    "//conditions:default": [],
})

# Gnulib conditional sources — each file is compiled only when its condition
# variable evaluates to true. Conditions come from three sources:
#   - REPLACE_*: upstream gnulib modules (function exists but is buggy/missing)
#   - COMPILE_*: configure_ac checks (function absent on platform)
#   - ac_cv_define_REPLACE_POSIX_SPAWN: spawn subsystem needs full replacement
autoconf_srcs(
    name = "gnulib_conditional_srcs",
    srcs = {
        # --- REPLACE_* gated (upstream gnulib decides) ---
        "lib/asprintf.c": "REPLACE_VASPRINTF",
        # --- COMPILE_* gated (function absent → replacement compiled) ---
        "lib/canonicalize-lgpl.c": "COMPILE_CANONICALIZE_LGPL",
        "lib/error.c": "COMPILE_ERROR",
        "lib/fcntl.c": "REPLACE_FCNTL",
        "lib/fopen.c": "REPLACE_FOPEN",
        "lib/fpending.c": "COMPILE_FPENDING",
        "lib/fprintf.c": "REPLACE_FPRINTF",
        "lib/free.c": "REPLACE_FREE",
        "lib/fseterr.c": "COMPILE_FSETERR",
        "lib/fstat.c": "REPLACE_FSTAT",
        "lib/getopt.c": "COMPILE_GETOPT",
        "lib/getopt1.c": "COMPILE_GETOPT",
        "lib/iconv_open.c": "REPLACE_ICONV_OPEN",
        "lib/lstat.c": "REPLACE_LSTAT",
        "lib/mbrtowc.c": "COMPILE_MBRTOWC",
        "lib/mempcpy.c": "COMPILE_MEMPCPY",
        "lib/obstack_printf.c": "COMPILE_OBSTACK_PRINTF",
        "lib/open.c": "COMPILE_OPEN",
        "lib/perror.c": "REPLACE_PERROR",
        "lib/printf.c": "REPLACE_PRINTF",
        "lib/rawmemchr.c": "COMPILE_RAWMEMCHR",
        "lib/readlink.c": "REPLACE_READLINK",
        "lib/reallocarray.c": "COMPILE_REALLOCARRAY",
        "lib/rename.c": "REPLACE_RENAME",
        "lib/snprintf.c": "REPLACE_SNPRINTF",
        # --- Spawn replacement (all-or-nothing when REPLACE_POSIX_SPAWN=1) ---
        "lib/spawn.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawn_faction_addchdir.c": "COMPILE_SPAWN_FACTION_ADDCHDIR",
        "lib/spawn_faction_addclose.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawn_faction_adddup2.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawn_faction_addopen.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawn_faction_destroy.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawn_faction_init.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawnattr_destroy.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawnattr_init.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawnattr_setflags.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawnattr_setpgroup.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawnattr_setsigmask.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawni.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/spawnp.c": "ac_cv_define_REPLACE_POSIX_SPAWN",
        "lib/sprintf.c": "REPLACE_SPRINTF",
        "lib/stat.c": "REPLACE_STAT",
        "lib/strchrnul.c": "REPLACE_STRCHRNUL",
        "lib/strerror-override.c": "COMPILE_STRERROR_OVERRIDE",
        "lib/strerror.c": "REPLACE_STRERROR",
        "lib/strerror_r.c": "REPLACE_STRERROR_R",
        "lib/strverscmp.c": "COMPILE_STRVERSCMP",
        "lib/unlink.c": "COMPILE_UNLINK",
        "lib/vasprintf.c": "REPLACE_VASPRINTF",
        "lib/vfprintf.c": "REPLACE_VFPRINTF",
        "lib/vsnprintf.c": "REPLACE_VSNPRINTF",
        "lib/vsprintf.c": "REPLACE_VSPRINTF",
    },
    defaults = True,
    deps = [":configure_ac"],
)

# Shared headers for lib/ targets (mirrors autotools AM_CPPFLAGS = -I./lib)
cc_library(
    name = "headers",
    hdrs = ["lib/config.h"] + [
        ":{}".format(hdr)
        for hdr in GENERATED_SRCS.keys()
    ] + glob(
        include = ["lib/**/*.h"],
        exclude = GENERATED_SRCS.keys() + [
            "lib/config.h",
            "lib/configmake.h",
        ],
    ) + [
        "src/scan-code.c",
        "src/scan-gram.c",
        "src/scan-skel.c",
        ":configmake_h_src",
    ],
    includes = ["lib"],
    textual_hdrs = [
        "lib/timevar.def",
        "lib/printf-frexp.c",
    ],
)

alias(
    name = "libbison",
    actual = ":lib/bison",
)

# Unconditional sources are always compiled on all platforms.
# Conditional sources are gated by autoconf_srcs targets based on actual
# check results (REPLACE_*, HAVE_*), matching native autoconf behavior.
cc_library(
    name = "lib/bison",
    srcs = [
        # === Unconditional sources (from lib_libbison_a_SOURCES in gnulib.mk) ===
        "lib/allocator.c",
        "lib/areadlink.c",
        "lib/argmatch.c",
        "lib/asnprintf.c",
        "lib/basename.c",
        "lib/basename-lgpl.c",
        "lib/binary-io.c",
        "lib/bitrotate.c",
        "lib/bitset.c",
        "lib/bitset/array.c",
        "lib/bitset/list.c",
        "lib/bitset/stats.c",
        "lib/bitset/table.c",
        "lib/bitset/vector.c",
        "lib/bitsetv.c",
        "lib/c-ctype.c",
        "lib/c-strcasecmp.c",
        "lib/c-strncasecmp.c",
        "lib/canonicalize.c",
        "lib/careadlinkat.c",
        "lib/cloexec.c",
        "lib/close-stream.c",
        "lib/closeout.c",
        "lib/concat-filename.c",
        "lib/dirname.c",
        "lib/dirname-lgpl.c",
        "lib/dup-safer.c",
        "lib/dup-safer-flag.c",
        "lib/execute.c",
        "lib/exitfail.c",
        "lib/fatal-signal.c",
        "lib/fd-safer.c",
        "lib/fd-safer-flag.c",
        "lib/file-set.c",
        "lib/findprog-in.c",
        "lib/fopen-safer.c",
        "lib/fstrcmp.c",
        "lib/get-errno.c",
        "lib/gethrxtime.c",
        "lib/getprogname.c",
        "lib/gettime.c",
        "lib/gl_array_list.c",
        "lib/gl_hash_map.c",
        "lib/gl_linked_list.c",
        "lib/gl_list.c",
        "lib/gl_map.c",
        "lib/gl_oset.c",
        "lib/gl_rbtree_oset.c",
        "lib/gl_rbtreehash_list.c",
        "lib/gl_xlist.c",
        "lib/gl_xmap.c",
        "lib/glthread/lock.c",
        "lib/glthread/threadlib.c",
        "lib/glthread/tls.c",
        "lib/hash.c",
        "lib/hash-pjw.c",
        "lib/hash-triple-simple.c",
        "lib/ialloc.c",
        "lib/integer_length.c",
        "lib/integer_length_l.c",
        "lib/localcharset.c",
        "lib/malloc/scratch_buffer_dupfree.c",
        "lib/malloc/scratch_buffer_grow.c",
        "lib/malloc/scratch_buffer_grow_preserve.c",
        "lib/malloc/scratch_buffer_set_array_size.c",
        "lib/math.c",
        "lib/mbchar.c",
        "lib/mbfile.c",
        "lib/mbswidth.c",
        "lib/obstack.c",
        "lib/path-join.c",
        "lib/pipe-safer.c",
        "lib/pipe2.c",
        "lib/pipe2-safer.c",
        "lib/printf-args.c",
        "lib/printf-frexp.c",
        "lib/printf-frexpl.c",
        "lib/printf-parse.c",
        "lib/progname.c",
        "lib/quotearg.c",
        "lib/readline.c",
        "lib/sig-handler.c",
        "lib/spawn-pipe.c",
        "lib/stripslash.c",
        "lib/timespec.c",
        "lib/timevar.c",
        "lib/unicodeio.c",
        "lib/unistd.c",
        "lib/unistr/u8-mbtoucr.c",
        "lib/unistr/u8-uctomb.c",
        "lib/unistr/u8-uctomb-aux.c",
        "lib/uniwidth/width.c",
        "lib/vasnprintf.c",
        "lib/wait-process.c",
        "lib/wctype-h.c",
        "lib/xalloc-die.c",
        "lib/xconcat-filename.c",
        "lib/xhash.c",
        "lib/xmalloc.c",
        "lib/xmemdup0.c",
        "lib/xreadlink.c",
        "lib/xsize.c",
        "lib/xstrndup.c",
        "lib/xtime.c",
        # Always-enabled gnulib modules (gl_GNULIB_ENABLED_* always true for bison)
        "lib/hard-locale.c",
        "lib/malloca.c",
        "lib/setlocale_null.c",
        "lib/stat-time.c",
    ] + [
        ":gnulib_conditional_srcs",
    ] + select({
        "@platforms//os:windows": [
            # POSIX function replacements (missing on Windows)
            "lib/ffsl.c",
            "lib/fsync.c",
            "lib/getdtablesize.c",
            "lib/getrusage.c",
            "lib/gettimeofday.c",
            "lib/pipe.c",
            "lib/sigaction.c",
            "lib/sigprocmask.c",
            "lib/stpcpy.c",
            "lib/stpncpy.c",
            "lib/strndup.c",
            "lib/waitpid.c",
            "lib/wcwidth.c",
            # Windows-specific gnulib support
            "lib/msvc-inval.c",
            "lib/msvc-nothrow.c",
            "lib/stat-w32.c",
            "lib/windows-mutex.c",
            "lib/windows-once.c",
            "lib/windows-recmutex.c",
            "lib/windows-rwlock.c",
            "lib/windows-spawn.c",
            "lib/windows-tls.c",
        ],
        "//conditions:default": [],
    }),
    copts = BISON_COPTS,
    local_defines = LOCAL_DEFINES + [
        "DEFAULT_TEXT_DOMAIN=\\\"bison-gnulib\\\"",
    ],
    deps = [":headers"],
)

alias(
    name = "liby",
    actual = ":lib/y",
)

cc_library(
    name = "lib/y",
    srcs = [
        "lib/main.c",
        "lib/yyerror.c",
    ],
    implementation_deps = [":headers"],
    local_defines = LOCAL_DEFINES,
)

BISON_SRC_SRCS = glob(
    include = [
        "src/*.c",
    ],
    exclude = [
        "src/bazel_runfiles.cc",
        "src/i18n-strings.c",
        "src/scan-code.c",
        "src/scan-gram.c",
        "src/scan-skel.c",
        "src/main.c",
    ],
)

BISON_HDRS_SRCS = glob(
    include = ["src/*.h"],
)

cc_library(
    name = "bison_bazel_runfiles",
    srcs = ["src/bazel_runfiles.cc"],
    deps = ["@rules_cc//cc/runfiles"],
)

# Runfiles for bison binary
filegroup(
    name = "bison_data",
    srcs = glob(["data/**/*"]) + [
        "@rules_m4//m4:current_m4_toolchain",
    ],
)

# Link options for different compilers
BISON_LINKOPTS = select({
    "@rules_cc//cc/compiler:msvc-cl": [
        # LNK4001: no object files specified; libraries used
        "/IGNORE:4001",
    ],
    "//conditions:default": [],
})

# Bison binary
cc_binary(
    name = "bin/bison",
    srcs = BISON_SRC_SRCS + ["src/main.c"] + BISON_HDRS_SRCS,
    copts = BISON_COPTS,
    data = [":bison_data"],
    includes = ["src"],
    linkopts = BISON_LINKOPTS + select({
        "@platforms//os:linux": ["-lpthread"],
        "@platforms//os:macos": ["-liconv"],
        "//conditions:default": [],
    }),
    local_defines = LOCAL_DEFINES,
    visibility = ["//visibility:public"],
    deps = [
        ":bison_bazel_runfiles",
        ":headers",
        ":libbison",
        ":liby",
    ],
)

alias(
    name = "bison",
    actual = ":bin/bison",
    visibility = ["//visibility:public"],
)

# Yacc binary (alias for bison)
alias(
    name = "yacc",
    actual = ":bin/bison",
    visibility = ["//visibility:public"],
)

genrule(
    name = "bison_help",
    testonly = True,
    outs = ["bison_help.txt"],
    cmd = "$(execpath :bison) --help > $@",
    cmd_bat = "$(execpath :bison) --help > $@",
    tools = [":bison"],
)