| 1 | # GCC_NO_EXECUTABLES |
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| 2 | # ----------------- |
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| 3 | # FIXME: The GCC team has specific needs which the current Autoconf |
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| 4 | # framework cannot solve elegantly. This macro implements a dirty |
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| 5 | # hack until Autoconf is able to provide the services its users |
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| 6 | # need. |
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| 7 | # |
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| 8 | # Several of the support libraries that are often built with GCC can't |
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| 9 | # assume the tool-chain is already capable of linking a program: the |
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| 10 | # compiler often expects to be able to link with some of such |
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| 11 | # libraries. |
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| 12 | # |
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| 13 | # In several of these libraries, workarounds have been introduced to |
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| 14 | # avoid the AC_PROG_CC_WORKS test, that would just abort their |
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| 15 | # configuration. The introduction of AC_EXEEXT, enabled either by |
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| 16 | # libtool or by CVS autoconf, have just made matters worse. |
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| 17 | # |
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| 18 | # Unlike the previous AC_NO_EXECUTABLES, this test does not |
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| 19 | # disable link tests at autoconf time, but at configure time. |
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| 20 | # This allows AC_NO_EXECUTABLES to be invoked conditionally. |
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| 21 | AC_DEFUN_ONCE([GCC_NO_EXECUTABLES], |
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| 22 | [m4_divert_push([KILL]) |
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| 23 | |
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| 24 | AC_BEFORE([$0], [_AC_COMPILER_EXEEXT]) |
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| 25 | AC_BEFORE([$0], [AC_LINK_IFELSE]) |
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| 26 | |
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| 27 | m4_define([_AC_COMPILER_EXEEXT], |
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| 28 | [AC_LANG_CONFTEST([AC_LANG_PROGRAM()]) |
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| 29 | # FIXME: Cleanup? |
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| 30 | AS_IF([AC_TRY_EVAL(ac_link)], [gcc_no_link=no], [gcc_no_link=yes]) |
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| 31 | if test x$gcc_no_link = xyes; then |
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| 32 | # Setting cross_compile will disable run tests; it will |
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| 33 | # also disable AC_CHECK_FILE but that's generally |
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| 34 | # correct if we can't link. |
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| 35 | cross_compiling=yes |
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| 36 | EXEEXT= |
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| 37 | else |
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| 38 | ]m4_defn([_AC_COMPILER_EXEEXT])dnl |
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| 39 | fi |
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| 40 | ) |
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| 41 | |
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| 42 | m4_define([AC_LINK_IFELSE], |
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| 43 | if test x$gcc_no_link = xyes; then |
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| 44 | AC_MSG_ERROR([Link tests are not allowed after [[$0]].]) |
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| 45 | fi |
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| 46 | m4_defn([AC_LINK_IFELSE])) |
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| 47 | |
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| 48 | dnl This is a shame. We have to provide a default for some link tests, |
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| 49 | dnl similar to the default for run tests. |
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| 50 | m4_define([AC_FUNC_MMAP], |
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| 51 | if test x$gcc_no_link = xyes; then |
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| 52 | if test "x${ac_cv_func_mmap_fixed_mapped+set}" != xset; then |
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| 53 | ac_cv_func_mmap_fixed_mapped=no |
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| 54 | fi |
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| 55 | fi |
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| 56 | if test "x${ac_cv_func_mmap_fixed_mapped}" != xno; then |
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| 57 | m4_defn([AC_FUNC_MMAP]) |
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| 58 | fi) |
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| 59 | |
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| 60 | m4_divert_pop()dnl |
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| 61 | ])# GCC_NO_EXECUTABLES |
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| 62 | |
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| 63 | # Use the strongest available test out of AC_TRY_COMPILE and AC_TRY_LINK. |
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| 64 | AC_DEFUN([GCC_TRY_COMPILE_OR_LINK], |
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| 65 | [if test x$gcc_no_link = xyes; then |
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| 66 | AC_TRY_COMPILE([$1], [$2], [$3], [$4]) |
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| 67 | else |
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| 68 | AC_TRY_LINK([$1], [$2], [$3], [$4]) |
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| 69 | fi]) |
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