acinclude.m4 19 KB

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  1. dnl
  2. dnl Unconditionally define a preprocessor macro, translating the shell
  3. dnl macro from yes/no to 1/0.
  4. dnl
  5. AC_DEFUN([LIBAT_DEFINE_YESNO], [
  6. yesno=`echo $2 | tr 'yesno' '1 0 '`
  7. AC_DEFINE_UNQUOTED([$1], $yesno, [$3])
  8. ])
  9. dnl
  10. dnl Iterate over all of the modes we're prepared to check.
  11. dnl
  12. AC_DEFUN([LIBAT_FORALL_MODES],
  13. [$1(QI,1)
  14. $1(HI,2)
  15. $1(SI,4)
  16. $1(DI,8)
  17. $1(TI,16)]
  18. )
  19. dnl
  20. dnl Check for builtin types by mode.
  21. dnl
  22. dnl A less interesting of size checking than autoconf normally provides.
  23. dnl We know that gcc always provides <stdint.h>, but we don't often
  24. dnl provide a builtin type for TImode.
  25. dnl
  26. AC_DEFUN([LIBAT_HAVE_INT_MODE],[
  27. AC_CACHE_CHECK([for $2 byte integer],[libat_cv_have_mode_$1],
  28. [AC_COMPILE_IFELSE([AC_LANG_SOURCE([int x __attribute__((mode($1)));])],
  29. [libat_cv_have_mode_$1=yes],[libat_cv_have_mode_$1=no])])
  30. LIBAT_DEFINE_YESNO([HAVE_INT$2], [$libat_cv_have_mode_$1],
  31. [Have support for $2 byte integers.])
  32. if test x$libat_cv_have_mode_$1 = xyes; then
  33. SIZES="$SIZES $2"
  34. fi
  35. ])
  36. dnl
  37. dnl Check for atomic builtins.
  38. dnl See:
  39. dnl http://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html
  40. dnl
  41. dnl This checks to see if the host supports the compiler-generated
  42. dnl builtins for atomic operations for various integral sizes.
  43. dnl
  44. AC_DEFUN([LIBAT_TEST_ATOMIC_INIT],[
  45. # Do link tests if possible, instead asm tests, limited to some platforms
  46. # see discussion in PR target/40134, PR libstdc++/40133 and the thread
  47. # starting at http://gcc.gnu.org/ml/gcc-patches/2009-07/msg00322.html
  48. atomic_builtins_link_tests=no
  49. if test x$gcc_no_link != xyes; then
  50. # Can do link tests. Limit to some tested platforms
  51. case "$host" in
  52. *-*-linux* | *-*-uclinux* | *-*-kfreebsd*-gnu | *-*-gnu*)
  53. atomic_builtins_link_tests=yes
  54. ;;
  55. esac
  56. fi
  57. ])
  58. AC_DEFUN([LIBAT_TEST_ATOMIC_BUILTIN],[
  59. AC_CACHE_CHECK([$1],[$2],[
  60. AC_LANG_CONFTEST([AC_LANG_PROGRAM([],[$3])])
  61. if test x$atomic_builtins_link_tests = xyes; then
  62. if AC_TRY_EVAL(ac_link); then
  63. eval $2=yes
  64. else
  65. eval $2=no
  66. fi
  67. else
  68. old_CFLAGS="$CFLAGS"
  69. # Compile unoptimized.
  70. CFLAGS="$CFLAGS -O0 -S"
  71. if AC_TRY_EVAL(ac_compile); then
  72. if grep __atomic_ conftest.s >/dev/null 2>&1 ; then
  73. eval $2=no
  74. else
  75. eval $2=yes
  76. fi
  77. else
  78. eval $2=no
  79. fi
  80. CFLAGS="$old_CFLAGS"
  81. fi
  82. rm -f conftest*
  83. ])
  84. ])
  85. dnl
  86. dnl Test if we have __atomic_load and __atomic_store for mode $1, size $2
  87. dnl
  88. AC_DEFUN([LIBAT_HAVE_ATOMIC_LOADSTORE],[
  89. LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_load/store for size $2],
  90. [libat_cv_have_at_ldst_$2],
  91. [typedef int T __attribute__((mode($1)));
  92. T *x; volatile T sink; asm("" : "=g"(x));
  93. sink = __atomic_load_n(x, 0);
  94. __atomic_store_n(x, sink, 0);])
  95. LIBAT_DEFINE_YESNO([HAVE_ATOMIC_LDST_$2], [$libat_cv_have_at_ldst_$2],
  96. [Have __atomic_load/store for $2 byte integers.])
  97. AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_LDST_$2 HAVE_ATOMIC_LDST_$2])
  98. AH_BOTTOM([#define FAST_ATOMIC_LDST_$2 HAVE_ATOMIC_LDST_$2])
  99. ])
  100. dnl
  101. dnl Test if we have __atomic_test_and_set for mode $1, size $2
  102. dnl
  103. AC_DEFUN([LIBAT_HAVE_ATOMIC_TAS],[
  104. LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_test_and_set for size $2],
  105. [libat_cv_have_at_tas_$2],
  106. [typedef int T __attribute__((mode($1))); T *x; asm("" : "=g"(x));
  107. __atomic_test_and_set(x, 0);])
  108. LIBAT_DEFINE_YESNO([HAVE_ATOMIC_TAS_$2], [$libat_cv_have_at_tas_$2],
  109. [Have __atomic_test_and_set for $2 byte integers.])
  110. AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_TAS_$2 HAVE_ATOMIC_TAS_$2])
  111. ])
  112. dnl
  113. dnl Test if we have __atomic_exchange for mode $1, size $2
  114. dnl
  115. AC_DEFUN([LIBAT_HAVE_ATOMIC_EXCHANGE],[
  116. LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_exchange for size $2],
  117. [libat_cv_have_at_exch_$2],
  118. [typedef int T __attribute__((mode($1))); T *x; asm("" : "=g"(x));
  119. __atomic_exchange_n(x, 0, 0);])
  120. LIBAT_DEFINE_YESNO([HAVE_ATOMIC_EXCHANGE_$2], [$libat_cv_have_at_exch_$2],
  121. [Have __atomic_exchange for $2 byte integers.])
  122. AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_EXCHANGE_$2 HAVE_ATOMIC_EXCHANGE_$2])
  123. ])
  124. dnl
  125. dnl Test if we have __atomic_compare_exchange for mode $1, size $2
  126. dnl
  127. AC_DEFUN([LIBAT_HAVE_ATOMIC_CAS],[
  128. LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_compare_exchange for size $2],
  129. [libat_cv_have_at_cas_$2],
  130. [typedef int T __attribute__((mode($1))); T *x, *y;
  131. asm("" : "=g"(x), "=g"(y));
  132. __atomic_compare_exchange_n(x, y, 0, 0, 0, 0);])
  133. LIBAT_DEFINE_YESNO([HAVE_ATOMIC_CAS_$2], [$libat_cv_have_at_cas_$2],
  134. [Have __atomic_compare_exchange for $2 byte integers.])
  135. AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_CAS_$2 HAVE_ATOMIC_CAS_$2])
  136. ])
  137. dnl
  138. dnl Test if we have __atomic_fetch_add for mode $1, size $2
  139. dnl
  140. AC_DEFUN([LIBAT_HAVE_ATOMIC_FETCH_ADD],[
  141. LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_fetch_add for size $2],
  142. [libat_cv_have_at_fadd_$2],
  143. [typedef int T __attribute__((mode($1))); T *x, y;
  144. asm("" : "=g"(x), "=g"(y));
  145. __atomic_fetch_add (x, y, 0);
  146. __atomic_add_fetch (x, y, 0);])
  147. LIBAT_DEFINE_YESNO([HAVE_ATOMIC_FETCH_ADD_$2], [$libat_cv_have_at_fadd_$2],
  148. [Have __atomic_fetch_add for $2 byte integers.])
  149. AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_FETCH_ADD_$2 HAVE_ATOMIC_FETCH_ADD_$2])
  150. ])
  151. dnl
  152. dnl Test if we have __atomic_fetch_op for all op for mode $1, size $2
  153. dnl
  154. AC_DEFUN([LIBAT_HAVE_ATOMIC_FETCH_OP],[
  155. LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_fetch_op for size $2],
  156. [libat_cv_have_at_fop_$2],
  157. [typedef int T __attribute__((mode($1))); T *x, y;
  158. asm("" : "=g"(x), "=g"(y));
  159. __atomic_fetch_add (x, y, 0); __atomic_add_fetch (x, y, 0);
  160. __atomic_fetch_sub (x, y, 0); __atomic_sub_fetch (x, y, 0);
  161. __atomic_fetch_and (x, y, 0); __atomic_and_fetch (x, y, 0);
  162. __atomic_fetch_nand (x, y, 0); __atomic_nand_fetch (x, y, 0);
  163. __atomic_fetch_xor (x, y, 0); __atomic_xor_fetch (x, y, 0);
  164. __atomic_fetch_or (x, y, 0); __atomic_or_fetch (x, y, 0); ])
  165. LIBAT_DEFINE_YESNO([HAVE_ATOMIC_FETCH_OP_$2], [$libat_cv_have_at_fop_$2],
  166. [Have __atomic_fetch_op for all op for $2 byte integers.])
  167. AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_FETCH_OP_$2 HAVE_ATOMIC_FETCH_OP_$2])
  168. ])
  169. dnl
  170. dnl Test for the size of the target word.
  171. dnl
  172. AC_DEFUN([LIBAT_WORDSIZE],[
  173. AC_CACHE_CHECK([for the word size],[libat_cv_wordsize],
  174. [AC_COMPUTE_INT(libat_cv_wordsize,
  175. [sizeof(word)], [typedef int word __attribute__((mode(word)));],
  176. AC_ERROR([Could not determine word size.]))])
  177. AC_DEFINE_UNQUOTED(WORDSIZE, $libat_cv_wordsize,
  178. [The word size in bytes of the machine.])
  179. ])
  180. dnl
  181. dnl Check whether the target supports the ifunc attribute.
  182. dnl
  183. AC_DEFUN([LIBAT_CHECK_IFUNC], [
  184. AC_CACHE_CHECK([whether the target supports the ifunc attribute],
  185. libat_cv_have_ifunc, [
  186. save_CFLAGS="$CFLAGS"
  187. CFLAGS="$CFLAGS -Werror"
  188. AC_TRY_LINK([
  189. int foo_alt(void) { return 0; }
  190. typedef int F (void);
  191. F *foo_sel(void) { return foo_alt; }
  192. int foo(void) __attribute__((ifunc("foo_sel")));],
  193. [return foo();], libat_cv_have_ifunc=yes, libat_cv_have_ifunc=no)])
  194. LIBAT_DEFINE_YESNO([HAVE_IFUNC], [$libat_cv_have_ifunc],
  195. [Define to 1 if the target supports __attribute__((ifunc(...))).])
  196. ])
  197. dnl ----------------------------------------------------------------------
  198. dnl This whole bit snagged from libitm.
  199. dnl Check whether the target supports hidden visibility.
  200. AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_VISIBILITY], [
  201. AC_CACHE_CHECK([whether the target supports hidden visibility],
  202. libat_cv_have_attribute_visibility, [
  203. save_CFLAGS="$CFLAGS"
  204. CFLAGS="$CFLAGS -Werror"
  205. AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }],
  206. [], libat_cv_have_attribute_visibility=yes,
  207. libat_cv_have_attribute_visibility=no)
  208. CFLAGS="$save_CFLAGS"])
  209. if test $libat_cv_have_attribute_visibility = yes; then
  210. AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
  211. [Define to 1 if the target supports __attribute__((visibility(...))).])
  212. fi])
  213. dnl Check whether the target supports dllexport
  214. AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_DLLEXPORT], [
  215. AC_CACHE_CHECK([whether the target supports dllexport],
  216. libat_cv_have_attribute_dllexport, [
  217. save_CFLAGS="$CFLAGS"
  218. CFLAGS="$CFLAGS -Werror"
  219. AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }],
  220. [], libat_cv_have_attribute_dllexport=yes,
  221. libat_cv_have_attribute_dllexport=no)
  222. CFLAGS="$save_CFLAGS"])
  223. if test $libat_cv_have_attribute_dllexport = yes; then
  224. AC_DEFINE(HAVE_ATTRIBUTE_DLLEXPORT, 1,
  225. [Define to 1 if the target supports __attribute__((dllexport)).])
  226. fi])
  227. dnl Check whether the target supports symbol aliases.
  228. AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_ALIAS], [
  229. AC_CACHE_CHECK([whether the target supports symbol aliases],
  230. libat_cv_have_attribute_alias, [
  231. AC_TRY_LINK([
  232. void foo(void) { }
  233. extern void bar(void) __attribute__((alias("foo")));],
  234. [bar();], libat_cv_have_attribute_alias=yes, libat_cv_have_attribute_alias=no)])
  235. if test $libat_cv_have_attribute_alias = yes; then
  236. AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
  237. [Define to 1 if the target supports __attribute__((alias(...))).])
  238. fi])
  239. dnl ----------------------------------------------------------------------
  240. dnl This whole bit snagged from libstdc++-v3.
  241. dnl
  242. dnl LIBAT_ENABLE
  243. dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
  244. dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
  245. dnl (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
  246. dnl
  247. dnl See docs/html/17_intro/configury.html#enable for documentation.
  248. dnl
  249. m4_define([LIBAT_ENABLE],[dnl
  250. m4_define([_g_switch],[--enable-$1])dnl
  251. m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
  252. AC_ARG_ENABLE($1,_g_help,
  253. m4_bmatch([$5],
  254. [^permit ],
  255. [[
  256. case "$enableval" in
  257. m4_bpatsubst([$5],[permit ])) ;;
  258. *) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
  259. dnl Idea for future: generate a URL pointing to
  260. dnl "onlinedocs/configopts.html#whatever"
  261. esac
  262. ]],
  263. [^$],
  264. [[
  265. case "$enableval" in
  266. yes|no) ;;
  267. *) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
  268. esac
  269. ]],
  270. [[$5]]),
  271. [enable_]m4_bpatsubst([$1],-,_)[=][$2])
  272. m4_undefine([_g_switch])dnl
  273. m4_undefine([_g_help])dnl
  274. ])
  275. dnl
  276. dnl If GNU ld is in use, check to see if tricky linker opts can be used. If
  277. dnl the native linker is in use, all variables will be defined to something
  278. dnl safe (like an empty string).
  279. dnl
  280. dnl Defines:
  281. dnl SECTION_LDFLAGS='-Wl,--gc-sections' if possible
  282. dnl OPT_LDFLAGS='-Wl,-O1' if possible
  283. dnl LD (as a side effect of testing)
  284. dnl Sets:
  285. dnl with_gnu_ld
  286. dnl libat_ld_is_gold (possibly)
  287. dnl libat_ld_is_mold (possibly)
  288. dnl libat_gnu_ld_version (possibly)
  289. dnl
  290. dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
  291. dnl set libat_gnu_ld_version to 12345. Zeros cause problems.
  292. dnl
  293. AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [
  294. # If we're not using GNU ld, then there's no point in even trying these
  295. # tests. Check for that first. We should have already tested for gld
  296. # by now (in libtool), but require it now just to be safe...
  297. test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
  298. test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
  299. AC_REQUIRE([AC_PROG_LD])
  300. AC_REQUIRE([AC_PROG_AWK])
  301. # The name set by libtool depends on the version of libtool. Shame on us
  302. # for depending on an impl detail, but c'est la vie. Older versions used
  303. # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
  304. # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
  305. # makes sense). We'll test with_gnu_ld everywhere else, so if that isn't
  306. # set (hence we're using an older libtool), then set it.
  307. if test x${with_gnu_ld+set} != xset; then
  308. if test x${ac_cv_prog_gnu_ld+set} != xset; then
  309. # We got through "ac_require(ac_prog_ld)" and still not set? Huh?
  310. with_gnu_ld=no
  311. else
  312. with_gnu_ld=$ac_cv_prog_gnu_ld
  313. fi
  314. fi
  315. # Start by getting the version number. I think the libtool test already
  316. # does some of this, but throws away the result.
  317. libat_ld_is_gold=no
  318. libat_ld_is_mold=no
  319. if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
  320. libat_ld_is_gold=yes
  321. elif $LD --version 2>/dev/null | grep 'mold' >/dev/null 2>&1; then
  322. libat_ld_is_mold=yes
  323. fi
  324. changequote(,)
  325. ldver=`$LD --version 2>/dev/null |
  326. sed -e 's/[. ][0-9]\{8\}$//;s/.* \([^ ]\{1,\}\)$/\1/; q'`
  327. changequote([,])
  328. libat_gnu_ld_version=`echo $ldver | \
  329. $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
  330. # Set --gc-sections.
  331. if test "$with_gnu_ld" = "notbroken"; then
  332. # GNU ld it is! Joy and bunny rabbits!
  333. # All these tests are for C++; save the language and the compiler flags.
  334. # Need to do this so that g++ won't try to link in libstdc++
  335. ac_test_CFLAGS="${CFLAGS+set}"
  336. ac_save_CFLAGS="$CFLAGS"
  337. CFLAGS='-x c++ -Wl,--gc-sections'
  338. # Check for -Wl,--gc-sections
  339. # XXX This test is broken at the moment, as symbols required for linking
  340. # are now in libsupc++ (not built yet). In addition, this test has
  341. # cored on solaris in the past. In addition, --gc-sections doesn't
  342. # really work at the moment (keeps on discarding used sections, first
  343. # .eh_frame and now some of the glibc sections for iconv).
  344. # Bzzzzt. Thanks for playing, maybe next time.
  345. AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
  346. AC_TRY_RUN([
  347. int main(void)
  348. {
  349. try { throw 1; }
  350. catch (...) { };
  351. return 0;
  352. }
  353. ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
  354. if test "$ac_test_CFLAGS" = set; then
  355. CFLAGS="$ac_save_CFLAGS"
  356. else
  357. # this is the suspicious part
  358. CFLAGS=''
  359. fi
  360. if test "$ac_sectionLDflags" = "yes"; then
  361. SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
  362. fi
  363. AC_MSG_RESULT($ac_sectionLDflags)
  364. fi
  365. # Set linker optimization flags.
  366. if test x"$with_gnu_ld" = x"yes"; then
  367. OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
  368. fi
  369. AC_SUBST(SECTION_LDFLAGS)
  370. AC_SUBST(OPT_LDFLAGS)
  371. ])
  372. dnl
  373. dnl Add version tags to symbols in shared library (or not), additionally
  374. dnl marking other symbols as private/local (or not).
  375. dnl
  376. dnl --enable-symvers=style adds a version script to the linker call when
  377. dnl creating the shared library. The choice of version script is
  378. dnl controlled by 'style'.
  379. dnl --disable-symvers does not.
  380. dnl + Usage: LIBAT_ENABLE_SYMVERS[(DEFAULT)]
  381. dnl Where DEFAULT is either 'yes' or 'no'. Passing `yes' tries to
  382. dnl choose a default style based on linker characteristics. Passing
  383. dnl 'no' disables versioning.
  384. dnl
  385. AC_DEFUN([LIBAT_ENABLE_SYMVERS], [
  386. LIBAT_ENABLE(symvers,yes,[=STYLE],
  387. [enables symbol versioning of the shared library],
  388. [permit yes|no|gnu*|sun])
  389. # If we never went through the LIBAT_CHECK_LINKER_FEATURES macro, then we
  390. # don't know enough about $LD to do tricks...
  391. AC_REQUIRE([LIBAT_CHECK_LINKER_FEATURES])
  392. # Turn a 'yes' into a suitable default.
  393. if test x$enable_symvers = xyes ; then
  394. # FIXME The following test is too strict, in theory.
  395. if test $enable_shared = no || test "x$LD" = x; then
  396. enable_symvers=no
  397. else
  398. if test $with_gnu_ld = yes ; then
  399. enable_symvers=gnu
  400. else
  401. case ${target_os} in
  402. # Sun symbol versioning exists since Solaris 2.5.
  403. solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
  404. enable_symvers=sun ;;
  405. *)
  406. enable_symvers=no ;;
  407. esac
  408. fi
  409. fi
  410. fi
  411. # Check if 'sun' was requested on non-Solaris 2 platforms.
  412. if test x$enable_symvers = xsun ; then
  413. case ${target_os} in
  414. solaris2*)
  415. # All fine.
  416. ;;
  417. *)
  418. # Unlikely to work.
  419. AC_MSG_WARN([=== You have requested Sun symbol versioning, but])
  420. AC_MSG_WARN([=== you are not targetting Solaris 2.])
  421. AC_MSG_WARN([=== Symbol versioning will be disabled.])
  422. enable_symvers=no
  423. ;;
  424. esac
  425. fi
  426. # Check to see if libgcc_s exists, indicating that shared libgcc is possible.
  427. if test $enable_symvers != no; then
  428. AC_MSG_CHECKING([for shared libgcc])
  429. ac_save_CFLAGS="$CFLAGS"
  430. CFLAGS=' -lgcc_s'
  431. AC_TRY_LINK(, [return 0;], libat_shared_libgcc=yes, libat_shared_libgcc=no)
  432. CFLAGS="$ac_save_CFLAGS"
  433. if test $libat_shared_libgcc = no; then
  434. cat > conftest.c <<EOF
  435. int main (void) { return 0; }
  436. EOF
  437. changequote(,)dnl
  438. libat_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
  439. -shared -shared-libgcc -o conftest.so \
  440. conftest.c -v 2>&1 >/dev/null \
  441. | sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
  442. changequote([,])dnl
  443. rm -f conftest.c conftest.so
  444. if test x${libat_libgcc_s_suffix+set} = xset; then
  445. CFLAGS=" -lgcc_s$libat_libgcc_s_suffix"
  446. AC_TRY_LINK(, [return 0;], libat_shared_libgcc=yes)
  447. CFLAGS="$ac_save_CFLAGS"
  448. fi
  449. fi
  450. AC_MSG_RESULT($libat_shared_libgcc)
  451. fi
  452. # For GNU ld, we need at least this version. The format is described in
  453. # LIBAT_CHECK_LINKER_FEATURES above.
  454. libat_min_gnu_ld_version=21400
  455. # XXXXXXXXXXX libat_gnu_ld_version=21390
  456. # Check to see if unspecified "yes" value can win, given results above.
  457. # Change "yes" into either "no" or a style name.
  458. if test $enable_symvers != no && test $libat_shared_libgcc = yes; then
  459. if test $with_gnu_ld = yes; then
  460. if test $libat_gnu_ld_version -ge $libat_min_gnu_ld_version ; then
  461. enable_symvers=gnu
  462. elif test $libat_ld_is_gold = yes ; then
  463. enable_symvers=gnu
  464. elif test $libat_ld_is_mold = yes ; then
  465. enable_symvers=gnu
  466. else
  467. # The right tools, the right setup, but too old. Fallbacks?
  468. AC_MSG_WARN(=== Linker version $libat_gnu_ld_version is too old for)
  469. AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
  470. AC_MSG_WARN(=== You would need to upgrade your binutils to version)
  471. AC_MSG_WARN(=== $libat_min_gnu_ld_version or later and rebuild GCC.)
  472. if test $libat_gnu_ld_version -ge 21200 ; then
  473. # Globbing fix is present, proper block support is not.
  474. dnl AC_MSG_WARN([=== Dude, you are soooo close. Maybe we can fake it.])
  475. dnl enable_symvers=???
  476. AC_MSG_WARN([=== Symbol versioning will be disabled.])
  477. enable_symvers=no
  478. else
  479. # 2.11 or older.
  480. AC_MSG_WARN([=== Symbol versioning will be disabled.])
  481. enable_symvers=no
  482. fi
  483. fi
  484. elif test $enable_symvers = sun; then
  485. : All interesting versions of Sun ld support sun style symbol versioning.
  486. else
  487. # just fail for now
  488. AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
  489. AC_MSG_WARN([=== either you are not using a supported linker, or you are])
  490. AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
  491. AC_MSG_WARN([=== Symbol versioning will be disabled.])
  492. enable_symvers=no
  493. fi
  494. fi
  495. if test $enable_symvers = gnu; then
  496. AC_DEFINE(LIBAT_GNU_SYMBOL_VERSIONING, 1,
  497. [Define to 1 if GNU symbol versioning is used for libatomic.])
  498. fi
  499. AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
  500. AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
  501. AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
  502. AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
  503. ])
  504. dnl ----------------------------------------------------------------------
  505. sinclude(../libtool.m4)
  506. sinclude(../config/enable.m4)
  507. sinclude(../config/cet.m4)
  508. dnl The lines below arrange for aclocal not to bring an installed
  509. dnl libtool.m4 into aclocal.m4, while still arranging for automake to
  510. dnl add a definition of LIBTOOL to Makefile.in.
  511. ifelse(,,,[AC_SUBST(LIBTOOL)
  512. AC_DEFUN([AM_PROG_LIBTOOL])
  513. AC_DEFUN([AC_LIBTOOL_DLOPEN])
  514. AC_DEFUN([AC_PROG_LD])
  515. ])