#!/bin/bash
# gnulib-cross-fix.sh — Fix gnulib cross-compilation misdetections in config.h
#
# Usage: gnulib-cross-fix.sh <path/to/lib/config.h>
#
# gnulib's configure can't run test programs during cross-compilation for
# x86_64-unknown-redox (relibc target). It assumes system headers/types are
# missing and generates broken fallback #defines and replacement headers.
#
# This script patches the generated config.h to correct those misdetections,
# telling gnulib that relibc provides standard POSIX headers and types.
#
# Call this AFTER configure but BEFORE make in any gnulib-based recipe:
#   "${COOKBOOK_CONFIGURE}" "${COOKBOOK_CONFIGURE_FLAGS[@]}"
#   gnulib-cross-fix.sh "${COOKBOOK_BUILD}/lib/config.h"
#   "${COOKBOOK_MAKE}" -j "${COOKBOOK_MAKE_JOBS}"

set -euo pipefail

CONFIG_H="${1:?Usage: gnulib-cross-fix.sh <path/to/config.h>}"

if [ ! -f "$CONFIG_H" ]; then
    echo "gnulib-cross-fix: $CONFIG_H not found, skipping" >&2
    exit 0
fi

echo "gnulib-cross-fix: patching $CONFIG_H for relibc cross-compilation"

# Comment out broken type fallbacks (relibc provides these correctly)
perl -pi -e 's,^#define gid_t int\b,/* #undef gid_t -- relibc provides */,' "$CONFIG_H"
perl -pi -e 's,^#define uid_t int\b,/* #undef uid_t -- relibc provides */,' "$CONFIG_H"
perl -pi -e 's,^#define intmax_t long long\b,/* #undef intmax_t -- relibc provides */,' "$CONFIG_H"
perl -pi -e 's,^#define ssize_t int\b,/* #undef ssize_t -- relibc provides */,' "$CONFIG_H"
perl -pi -e 's,^#define ptrdiff_t long\b,/* #undef ptrdiff_t -- relibc provides */,' "$CONFIG_H"
perl -pi -e 's,^#define nlink_t int\b,/* #undef nlink_t -- relibc provides */,' "$CONFIG_H"
perl -pi -e 's,^#define mbstate_t int\b,/* #undef mbstate_t -- relibc provides */,' "$CONFIG_H"

# Force HAVE_ macros for standard headers (gnulib can't detect these during cross-compilation)
for macro in \
    HAVE_INTTYPES_H \
    HAVE_INTTYPES_H_WITH_UINTMAX \
    HAVE_INTMAX_T \
    HAVE_WCHAR_H \
    HAVE_WCTYPE_H \
    HAVE_STDLIB_H \
    HAVE_SPAWN_H \
    HAVE_POSIX_SPAWNATTR_T \
    HAVE_POSIX_SPAWN_FILE_ACTIONS_T \
    HAVE_SIGNED_WCHAR_T \
    HAVE_SIGSET_T \
    HAVE_SIGACTION \
    HAVE_SIGADDSET \
    HAVE_SIGDELSET \
    HAVE_SIGEMPTYSET \
    HAVE_SIGFILLSET \
    HAVE_SIGISMEMBER \
    HAVE_SIGPENDING \
    HAVE_SIGPROCMASK \
    HAVE_SIGSUSPEND \
    HAVE_BTOWC \
    HAVE_MBRTOWC \
    HAVE_MBSINIT \
    HAVE_WCRTOMB \
    HAVE_WCTOB \
    HAVE_WCWIDTH \
    HAVE_MBSRTOWCS \
    HAVE_WCSWIDTH \
; do
    perl -pi -e "s,/\\* #undef ${macro} \\*/,#define ${macro} 1," "$CONFIG_H" || true
done

# Also patch generated replacement headers to disable rpl_ function renames.
# gnulib generates lib/wchar.h, lib/signal.h, lib/stdio.h etc. with #define func rpl_func
# when REPLACE_* is 1. Since relibc provides these functions, we need to undo the renames.
LIB_DIR="$(dirname "$CONFIG_H")"
for hdr in "$LIB_DIR"/wchar.h "$LIB_DIR"/signal.h "$LIB_DIR"/stdio.h "$LIB_DIR"/stdlib.h "$LIB_DIR"/string.h; do
    if [ -f "$hdr" ]; then
        # Replace rpl_ function names with the originals in #define lines
        # e.g. #define btowc rpl_btowc → /* #define btowc rpl_btowc -- relibc provides */
        perl -pi -e 's,^#(\s*)define (\w+) rpl_\2,/* #$1define $2 rpl_$2 -- relibc provides */,' "$hdr" || true
    fi
done

# NOTE: We do NOT replace #include_next directives. The cross-compiler (Clang)
# supports #include_next natively and the sysroot include path is set up correctly
# so that #include_next skips the build directory and finds relibc's system headers.
#
# Previous versions of this script replaced #include_next <X.h> with #include <X.h>,
# but this caused self-recursion in newer gnulib (m4-1.14+, flex) that removed the
# _GL_ALREADY_INCLUDING_WCHAR_H guard. The split double-inclusion guard pattern
# (_GL_WCHAR_H etc.) prevents re-entry into the normal section, but the special
# invocation section (for __need_mbstate_t/__need_wint_t) is unguarded and would
# recurse if #include found the gnulib wrapper instead of the system header.

echo "gnulib-cross-fix: done"