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799f78a92c
* lib/endian.c, lib/endian.in.h, m4/endian_h.m4, m4/sys_cdefs_h.m4: New files, copied from Gnulib.
104 lines
2.8 KiB
Plaintext
104 lines
2.8 KiB
Plaintext
# endian_h.m4
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# serial 4
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dnl Copyright 2024 Free Software Foundation, Inc.
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dnl This file is free software; the Free Software Foundation
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dnl gives unlimited permission to copy and/or distribute it,
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dnl with or without modifications, as long as this notice is preserved.
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dnl A placeholder for <endian.h>, for platforms that have issues.
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AC_DEFUN_ONCE([gl_ENDIAN_H],
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[
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AC_REQUIRE([gl_BIGENDIAN])
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AC_CHECK_HEADERS_ONCE([endian.h])
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gl_CHECK_NEXT_HEADERS([endian.h])
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if test $ac_cv_header_endian_h = yes; then
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HAVE_ENDIAN_H=1
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dnl Check if endian.h defines uint16_t, uint32_t, and uint64_t.
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AC_CACHE_CHECK([if endian.h defines stdint types],
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[gl_cv_header_endian_h_stdint_types],
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[AC_COMPILE_IFELSE(
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[AC_LANG_PROGRAM(
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[[#include <endian.h>
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]],
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[[uint16_t t1 = 0;
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uint32_t t2 = 0;
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uint64_t t3 = 0;
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return !(t1 + t2 + t3);
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]])],
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[gl_cv_header_endian_h_stdint_types=yes],
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[gl_cv_header_endian_h_stdint_types=no])
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])
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AC_CACHE_CHECK([if endian.h defines functions and macros],
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[gl_cv_header_working_endian_h],
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[gl_cv_header_working_endian_h=no
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AC_COMPILE_IFELSE(
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[AC_LANG_PROGRAM(
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[[
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#include <endian.h>
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]],
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[[
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#if LITTLE_ENDIAN == BIG_ENDIAN
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# error "Endian macros not unique."
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#endif
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#if BYTE_ORDER != LITTLE_ENDIAN && BYTE_ORDER != BIG_ENDIAN
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# error "Byte order not defined."
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#endif
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/* Big endian to host. */
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int value16_1 = be16toh (0.0);
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int value32_1 = be32toh (0.0);
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int value64_1 = be64toh (0.0);
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/* Host to big endian. */
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int value16_2 = htobe16 (0.0);
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int value32_2 = htobe32 (0.0);
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int value64_2 = htobe64 (0.0);
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/* Little endian to host. */
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int value16_3 = le16toh (0.0);
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int value32_3 = le32toh (0.0);
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int value64_3 = le64toh (0.0);
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/* Host to little endian. */
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int value16_4 = htole16 (0.0);
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int value32_4 = htole32 (0.0);
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int value64_4 = htole64 (0.0);
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/* Make sure the variables get used. */
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return !(value16_1 + value32_1 + value64_1
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+ value16_2 + value32_2 + value64_2
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+ value16_3 + value32_3 + value64_3
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+ value16_4 + value32_4 + value64_4);
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]])],
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[gl_cv_header_working_endian_h=yes],
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[gl_cv_header_working_endian_h=no])
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])
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else
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HAVE_ENDIAN_H=0
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fi
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dnl Check if endian.h should be generated.
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if test "$gl_cv_header_endian_h_stdint_types" = yes \
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&& test "$gl_cv_header_working_endian_h" = yes; then
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GL_GENERATE_ENDIAN_H=false
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else
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GL_GENERATE_ENDIAN_H=true
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fi
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dnl Check if endian.h works but is missing types from stdint.h.
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if test $GL_GENERATE_ENDIAN_H; then
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if test "$gl_cv_header_working_endian_h" = yes; then
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ENDIAN_H_JUST_MISSING_STDINT=1
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else
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ENDIAN_H_JUST_MISSING_STDINT=0
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fi
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else
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ENDIAN_H_JUST_MISSING_STDINT=0
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fi
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AC_SUBST([HAVE_ENDIAN_H])
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AC_SUBST([ENDIAN_H_JUST_MISSING_STDINT])
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])
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