1dnl
2dnl Unconditionally define a preprocessor macro, translating the shell
3dnl macro from yes/no to 1/0.
4dnl
5AC_DEFUN([LIBAT_DEFINE_YESNO], [
6  yesno=`echo $2 | tr 'yesno' '1  0 '`
7  AC_DEFINE_UNQUOTED([$1], $yesno, [$3])
8])
9dnl
10dnl Iterate over all of the modes we're prepared to check.
11dnl
12AC_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)
19dnl
20dnl Check for builtin types by mode.
21dnl
22dnl A less interesting of size checking than autoconf normally provides.
23dnl We know that gcc always provides <stdint.h>, but we don't often
24dnl provide a builtin type for TImode.
25dnl
26AC_DEFUN([LIBAT_HAVE_INT_MODE],[
27  AC_CACHE_CHECK([for $2 byte integer],[libat_cv_have_mode_$1],
28    [AC_COMPILE_IFELSE([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 $2"
34  fi
35])
36dnl
37dnl Check for atomic builtins.
38dnl See:
39dnl http://gcc.gnu.org/onlinedocs/gcc/_005f_005fatomic-Builtins.html
40dnl
41dnl This checks to see if the host supports the compiler-generated
42dnl builtins for atomic operations for various integral sizes.
43dnl
44AC_DEFUN([LIBAT_TEST_ATOMIC_INIT],[
45  # Do link tests if possible, instead asm tests, limited to some platforms
46  # see discussion in PR target/40134, PR libstdc++/40133 and the thread
47  # starting at http://gcc.gnu.org/ml/gcc-patches/2009-07/msg00322.html
48  atomic_builtins_link_tests=no
49  if test x$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])
58AC_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
86dnl
87dnl Test if we have __atomic_load and __atomic_store for mode $1, size $2
88dnl
89AC_DEFUN([LIBAT_HAVE_ATOMIC_LOADSTORE],[
90  LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_load/store for size $2],
91    [libat_cv_have_at_ldst_$2],
92    [typedef int T __attribute__((mode($1)));
93     T *x; volatile T sink; asm("" : "=g"(x));
94     sink = __atomic_load_n(x, 0);
95     __atomic_store_n(x, sink, 0);])
96  LIBAT_DEFINE_YESNO([HAVE_ATOMIC_LDST_$2], [$libat_cv_have_at_ldst_$2],
97	[Have __atomic_load/store for $2 byte integers.])
98  AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_LDST_$2 HAVE_ATOMIC_LDST_$2])
99  AH_BOTTOM([#define FAST_ATOMIC_LDST_$2 HAVE_ATOMIC_LDST_$2])
100])
101
102dnl
103dnl Test if we have __atomic_test_and_set for mode $1, size $2
104dnl
105AC_DEFUN([LIBAT_HAVE_ATOMIC_TAS],[
106  LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_test_and_set for size $2],
107    [libat_cv_have_at_tas_$2],
108    [typedef int T __attribute__((mode($1))); T *x; asm("" : "=g"(x));
109     __atomic_test_and_set(x, 0);])
110  LIBAT_DEFINE_YESNO([HAVE_ATOMIC_TAS_$2], [$libat_cv_have_at_tas_$2],
111	[Have __atomic_test_and_set for $2 byte integers.])
112  AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_TAS_$2 HAVE_ATOMIC_TAS_$2])
113])
114
115dnl
116dnl Test if we have __atomic_exchange for mode $1, size $2
117dnl
118AC_DEFUN([LIBAT_HAVE_ATOMIC_EXCHANGE],[
119  LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_exchange for size $2],
120    [libat_cv_have_at_exch_$2],
121    [typedef int T __attribute__((mode($1))); T *x; asm("" : "=g"(x));
122     __atomic_exchange_n(x, 0, 0);])
123  LIBAT_DEFINE_YESNO([HAVE_ATOMIC_EXCHANGE_$2], [$libat_cv_have_at_exch_$2],
124	[Have __atomic_exchange for $2 byte integers.])
125  AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_EXCHANGE_$2 HAVE_ATOMIC_EXCHANGE_$2])
126])
127
128dnl
129dnl Test if we have __atomic_compare_exchange for mode $1, size $2
130dnl
131AC_DEFUN([LIBAT_HAVE_ATOMIC_CAS],[
132  LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_compare_exchange for size $2],
133    [libat_cv_have_at_cas_$2],
134    [typedef int T __attribute__((mode($1))); T *x, *y;
135     asm("" : "=g"(x), "=g"(y));
136     __atomic_compare_exchange_n(x, y, 0, 0, 0, 0);])
137  LIBAT_DEFINE_YESNO([HAVE_ATOMIC_CAS_$2], [$libat_cv_have_at_cas_$2],
138	[Have __atomic_compare_exchange for $2 byte integers.])
139  AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_CAS_$2 HAVE_ATOMIC_CAS_$2])
140])
141
142dnl
143dnl Test if we have __atomic_fetch_add for mode $1, size $2
144dnl
145AC_DEFUN([LIBAT_HAVE_ATOMIC_FETCH_ADD],[
146  LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_fetch_add for size $2],
147    [libat_cv_have_at_fadd_$2],
148    [typedef int T __attribute__((mode($1))); T *x, y;
149     asm("" : "=g"(x), "=g"(y));
150     __atomic_fetch_add (x, y, 0);
151     __atomic_add_fetch (x, y, 0);])
152  LIBAT_DEFINE_YESNO([HAVE_ATOMIC_FETCH_ADD_$2], [$libat_cv_have_at_fadd_$2],
153	[Have __atomic_fetch_add for $2 byte integers.])
154  AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_FETCH_ADD_$2 HAVE_ATOMIC_FETCH_ADD_$2])
155])
156
157dnl
158dnl Test if we have __atomic_fetch_op for all op for mode $1, size $2
159dnl
160AC_DEFUN([LIBAT_HAVE_ATOMIC_FETCH_OP],[
161  LIBAT_TEST_ATOMIC_BUILTIN([for __atomic_fetch_op for size $2],
162    [libat_cv_have_at_fop_$2],
163    [typedef int T __attribute__((mode($1))); T *x, y;
164     asm("" : "=g"(x), "=g"(y));
165     __atomic_fetch_add (x, y, 0); __atomic_add_fetch (x, y, 0);
166     __atomic_fetch_sub (x, y, 0); __atomic_sub_fetch (x, y, 0);
167     __atomic_fetch_and (x, y, 0); __atomic_and_fetch (x, y, 0);
168     __atomic_fetch_nand (x, y, 0); __atomic_nand_fetch (x, y, 0);
169     __atomic_fetch_xor (x, y, 0); __atomic_xor_fetch (x, y, 0);
170     __atomic_fetch_or (x, y, 0);  __atomic_or_fetch (x, y, 0); ])
171  LIBAT_DEFINE_YESNO([HAVE_ATOMIC_FETCH_OP_$2], [$libat_cv_have_at_fop_$2],
172	[Have __atomic_fetch_op for all op for $2 byte integers.])
173  AH_BOTTOM([#define MAYBE_HAVE_ATOMIC_FETCH_OP_$2 HAVE_ATOMIC_FETCH_OP_$2])
174])
175
176dnl
177dnl Test for the size of the target word.
178dnl
179AC_DEFUN([LIBAT_WORDSIZE],[
180  AC_CACHE_CHECK([for the word size],[libat_cv_wordsize],
181    [AC_COMPUTE_INT(libat_cv_wordsize,
182      [sizeof(word)], [typedef int word __attribute__((mode(word)));],
183      AC_ERROR([Could not determine word size.]))])
184  AC_DEFINE_UNQUOTED(WORDSIZE, $libat_cv_wordsize,
185    [The word size in bytes of the machine.])
186])
187
188dnl
189dnl Check whether the target supports the ifunc attribute.
190dnl
191AC_DEFUN([LIBAT_CHECK_IFUNC], [
192  AC_CACHE_CHECK([whether the target supports the ifunc attribute],
193		 libat_cv_have_ifunc, [
194  save_CFLAGS="$CFLAGS"
195  CFLAGS="$CFLAGS -Werror"
196  AC_TRY_LINK([
197    int foo_alt(void) { return 0; }
198    typedef int F (void);
199    F *foo_sel(void) { return foo_alt; }
200    int foo(void) __attribute__((ifunc("foo_sel")));],
201    [return foo();], libat_cv_have_ifunc=yes, libat_cv_have_ifunc=no)])
202  LIBAT_DEFINE_YESNO([HAVE_IFUNC], [$libat_cv_have_ifunc],
203      [Define to 1 if the target supports __attribute__((ifunc(...))).])
204])
205
206dnl ----------------------------------------------------------------------
207dnl This whole bit snagged from libitm.
208
209dnl Check whether the target supports hidden visibility.
210AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_VISIBILITY], [
211  AC_CACHE_CHECK([whether the target supports hidden visibility],
212		 libat_cv_have_attribute_visibility, [
213  save_CFLAGS="$CFLAGS"
214  CFLAGS="$CFLAGS -Werror"
215  AC_TRY_COMPILE([void __attribute__((visibility("hidden"))) foo(void) { }],
216		 [], libat_cv_have_attribute_visibility=yes,
217		 libat_cv_have_attribute_visibility=no)
218  CFLAGS="$save_CFLAGS"])
219  if test $libat_cv_have_attribute_visibility = yes; then
220    AC_DEFINE(HAVE_ATTRIBUTE_VISIBILITY, 1,
221      [Define to 1 if the target supports __attribute__((visibility(...))).])
222  fi])
223
224dnl Check whether the target supports dllexport
225AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_DLLEXPORT], [
226  AC_CACHE_CHECK([whether the target supports dllexport],
227		 libat_cv_have_attribute_dllexport, [
228  save_CFLAGS="$CFLAGS"
229  CFLAGS="$CFLAGS -Werror"
230  AC_TRY_COMPILE([void __attribute__((dllexport)) foo(void) { }],
231		 [], libat_cv_have_attribute_dllexport=yes,
232		 libat_cv_have_attribute_dllexport=no)
233  CFLAGS="$save_CFLAGS"])
234  if test $libat_cv_have_attribute_dllexport = yes; then
235    AC_DEFINE(HAVE_ATTRIBUTE_DLLEXPORT, 1,
236      [Define to 1 if the target supports __attribute__((dllexport)).])
237  fi])
238
239dnl Check whether the target supports symbol aliases.
240AC_DEFUN([LIBAT_CHECK_ATTRIBUTE_ALIAS], [
241  AC_CACHE_CHECK([whether the target supports symbol aliases],
242		 libat_cv_have_attribute_alias, [
243  AC_TRY_LINK([
244void foo(void) { }
245extern void bar(void) __attribute__((alias("foo")));],
246    [bar();], libat_cv_have_attribute_alias=yes, libat_cv_have_attribute_alias=no)])
247  if test $libat_cv_have_attribute_alias = yes; then
248    AC_DEFINE(HAVE_ATTRIBUTE_ALIAS, 1,
249      [Define to 1 if the target supports __attribute__((alias(...))).])
250  fi])
251
252dnl ----------------------------------------------------------------------
253dnl This whole bit snagged from libstdc++-v3.
254
255dnl
256dnl LIBAT_ENABLE
257dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
258dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
259dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
260dnl
261dnl See docs/html/17_intro/configury.html#enable for documentation.
262dnl
263m4_define([LIBAT_ENABLE],[dnl
264m4_define([_g_switch],[--enable-$1])dnl
265m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
266 AC_ARG_ENABLE($1,_g_help,
267  m4_bmatch([$5],
268   [^permit ],
269     [[
270      case "$enableval" in
271       m4_bpatsubst([$5],[permit ])) ;;
272       *) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
273          dnl Idea for future:  generate a URL pointing to
274          dnl "onlinedocs/configopts.html#whatever"
275      esac
276     ]],
277   [^$],
278     [[
279      case "$enableval" in
280       yes|no) ;;
281       *) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
282      esac
283     ]],
284   [[$5]]),
285  [enable_]m4_bpatsubst([$1],-,_)[=][$2])
286m4_undefine([_g_switch])dnl
287m4_undefine([_g_help])dnl
288])
289
290dnl
291dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
292dnl the native linker is in use, all variables will be defined to something
293dnl safe (like an empty string).
294dnl
295dnl Defines:
296dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
297dnl  OPT_LDFLAGS='-Wl,-O1' if possible
298dnl  LD (as a side effect of testing)
299dnl Sets:
300dnl  with_gnu_ld
301dnl  libat_ld_is_gold (possibly)
302dnl  libat_gnu_ld_version (possibly)
303dnl
304dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
305dnl set libat_gnu_ld_version to 12345.  Zeros cause problems.
306dnl
307AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [
308  # If we're not using GNU ld, then there's no point in even trying these
309  # tests.  Check for that first.  We should have already tested for gld
310  # by now (in libtool), but require it now just to be safe...
311  test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
312  test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
313  AC_REQUIRE([AC_PROG_LD])
314  AC_REQUIRE([AC_PROG_AWK])
315
316  # The name set by libtool depends on the version of libtool.  Shame on us
317  # for depending on an impl detail, but c'est la vie.  Older versions used
318  # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
319  # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
320  # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't
321  # set (hence we're using an older libtool), then set it.
322  if test x${with_gnu_ld+set} != xset; then
323    if test x${ac_cv_prog_gnu_ld+set} != xset; then
324      # We got through "ac_require(ac_prog_ld)" and still not set?  Huh?
325      with_gnu_ld=no
326    else
327      with_gnu_ld=$ac_cv_prog_gnu_ld
328    fi
329  fi
330
331  # Start by getting the version number.  I think the libtool test already
332  # does some of this, but throws away the result.
333  libat_ld_is_gold=no
334  if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
335    libat_ld_is_gold=yes
336  fi
337  changequote(,)
338  ldver=`$LD --version 2>/dev/null |
339         sed -e 's/GNU gold /GNU ld /;s/GNU ld version /GNU ld /;s/GNU ld ([^)]*) /GNU ld /;s/GNU ld \([0-9.][0-9.]*\).*/\1/; q'`
340  changequote([,])
341  libat_gnu_ld_version=`echo $ldver | \
342         $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
343
344  # Set --gc-sections.
345  if test "$with_gnu_ld" = "notbroken"; then
346    # GNU ld it is!  Joy and bunny rabbits!
347
348    # All these tests are for C++; save the language and the compiler flags.
349    # Need to do this so that g++ won't try to link in libstdc++
350    ac_test_CFLAGS="${CFLAGS+set}"
351    ac_save_CFLAGS="$CFLAGS"
352    CFLAGS='-x c++  -Wl,--gc-sections'
353
354    # Check for -Wl,--gc-sections
355    # XXX This test is broken at the moment, as symbols required for linking
356    # are now in libsupc++ (not built yet).  In addition, this test has
357    # cored on solaris in the past.  In addition, --gc-sections doesn't
358    # really work at the moment (keeps on discarding used sections, first
359    # .eh_frame and now some of the glibc sections for iconv).
360    # Bzzzzt.  Thanks for playing, maybe next time.
361    AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
362    AC_TRY_RUN([
363     int main(void)
364     {
365       try { throw 1; }
366       catch (...) { };
367       return 0;
368     }
369    ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
370    if test "$ac_test_CFLAGS" = set; then
371      CFLAGS="$ac_save_CFLAGS"
372    else
373      # this is the suspicious part
374      CFLAGS=''
375    fi
376    if test "$ac_sectionLDflags" = "yes"; then
377      SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
378    fi
379    AC_MSG_RESULT($ac_sectionLDflags)
380  fi
381
382  # Set linker optimization flags.
383  if test x"$with_gnu_ld" = x"yes"; then
384    OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
385  fi
386
387  AC_SUBST(SECTION_LDFLAGS)
388  AC_SUBST(OPT_LDFLAGS)
389])
390
391
392dnl
393dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
394dnl the native linker is in use, all variables will be defined to something
395dnl safe (like an empty string).
396dnl
397dnl Defines:
398dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
399dnl  OPT_LDFLAGS='-Wl,-O1' if possible
400dnl  LD (as a side effect of testing)
401dnl Sets:
402dnl  with_gnu_ld
403dnl  libat_ld_is_gold (possibly)
404dnl  libat_gnu_ld_version (possibly)
405dnl
406dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
407dnl set libat_gnu_ld_version to 12345.  Zeros cause problems.
408dnl
409AC_DEFUN([LIBAT_CHECK_LINKER_FEATURES], [
410  # If we're not using GNU ld, then there's no point in even trying these
411  # tests.  Check for that first.  We should have already tested for gld
412  # by now (in libtool), but require it now just to be safe...
413  test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
414  test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
415  AC_REQUIRE([AC_PROG_LD])
416  AC_REQUIRE([AC_PROG_AWK])
417
418  # The name set by libtool depends on the version of libtool.  Shame on us
419  # for depending on an impl detail, but c'est la vie.  Older versions used
420  # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
421  # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
422  # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't
423  # set (hence we're using an older libtool), then set it.
424  if test x${with_gnu_ld+set} != xset; then
425    if test x${ac_cv_prog_gnu_ld+set} != xset; then
426      # We got through "ac_require(ac_prog_ld)" and still not set?  Huh?
427      with_gnu_ld=no
428    else
429      with_gnu_ld=$ac_cv_prog_gnu_ld
430    fi
431  fi
432
433  # Start by getting the version number.  I think the libtool test already
434  # does some of this, but throws away the result.
435  libat_ld_is_gold=no
436  if $LD --version 2>/dev/null | grep 'GNU gold'> /dev/null 2>&1; then
437    libat_ld_is_gold=yes
438  fi
439  changequote(,)
440  ldver=`$LD --version 2>/dev/null |
441         sed -e 's/GNU gold /GNU ld /;s/GNU ld version /GNU ld /;s/GNU ld ([^)]*) /GNU ld /;s/GNU ld \([0-9.][0-9.]*\).*/\1/; q'`
442  changequote([,])
443  libat_gnu_ld_version=`echo $ldver | \
444         $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
445
446  # Set --gc-sections.
447  if test "$with_gnu_ld" = "notbroken"; then
448    # GNU ld it is!  Joy and bunny rabbits!
449
450    # All these tests are for C++; save the language and the compiler flags.
451    # Need to do this so that g++ won't try to link in libstdc++
452    ac_test_CFLAGS="${CFLAGS+set}"
453    ac_save_CFLAGS="$CFLAGS"
454    CFLAGS='-x c++  -Wl,--gc-sections'
455
456    # Check for -Wl,--gc-sections
457    # XXX This test is broken at the moment, as symbols required for linking
458    # are now in libsupc++ (not built yet).  In addition, this test has
459    # cored on solaris in the past.  In addition, --gc-sections doesn't
460    # really work at the moment (keeps on discarding used sections, first
461    # .eh_frame and now some of the glibc sections for iconv).
462    # Bzzzzt.  Thanks for playing, maybe next time.
463    AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
464    AC_TRY_RUN([
465     int main(void)
466     {
467       try { throw 1; }
468       catch (...) { };
469       return 0;
470     }
471    ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
472    if test "$ac_test_CFLAGS" = set; then
473      CFLAGS="$ac_save_CFLAGS"
474    else
475      # this is the suspicious part
476      CFLAGS=''
477    fi
478    if test "$ac_sectionLDflags" = "yes"; then
479      SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
480    fi
481    AC_MSG_RESULT($ac_sectionLDflags)
482  fi
483
484  # Set linker optimization flags.
485  if test x"$with_gnu_ld" = x"yes"; then
486    OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
487  fi
488
489  AC_SUBST(SECTION_LDFLAGS)
490  AC_SUBST(OPT_LDFLAGS)
491])
492
493
494dnl
495dnl Add version tags to symbols in shared library (or not), additionally
496dnl marking other symbols as private/local (or not).
497dnl
498dnl --enable-symvers=style adds a version script to the linker call when
499dnl       creating the shared library.  The choice of version script is
500dnl       controlled by 'style'.
501dnl --disable-symvers does not.
502dnl  +  Usage:  LIBAT_ENABLE_SYMVERS[(DEFAULT)]
503dnl       Where DEFAULT is either 'yes' or 'no'.  Passing `yes' tries to
504dnl       choose a default style based on linker characteristics.  Passing
505dnl       'no' disables versioning.
506dnl
507AC_DEFUN([LIBAT_ENABLE_SYMVERS], [
508
509LIBAT_ENABLE(symvers,yes,[=STYLE],
510  [enables symbol versioning of the shared library],
511  [permit yes|no|gnu*|sun])
512
513# If we never went through the LIBAT_CHECK_LINKER_FEATURES macro, then we
514# don't know enough about $LD to do tricks...
515AC_REQUIRE([LIBAT_CHECK_LINKER_FEATURES])
516
517# Turn a 'yes' into a suitable default.
518if test x$enable_symvers = xyes ; then
519  # FIXME  The following test is too strict, in theory.
520  if test $enable_shared = no || test "x$LD" = x; then
521    enable_symvers=no
522  else
523    if test $with_gnu_ld = yes ; then
524      enable_symvers=gnu
525    else
526      case ${target_os} in
527        # Sun symbol versioning exists since Solaris 2.5.
528        solaris2.[[5-9]]* | solaris2.1[[0-9]]*)
529          enable_symvers=sun ;;
530        *)
531          enable_symvers=no ;;
532      esac
533    fi
534  fi
535fi
536
537# Check if 'sun' was requested on non-Solaris 2 platforms.
538if test x$enable_symvers = xsun ; then
539  case ${target_os} in
540    solaris2*)
541      # All fine.
542      ;;
543    *)
544      # Unlikely to work.
545      AC_MSG_WARN([=== You have requested Sun symbol versioning, but])
546      AC_MSG_WARN([=== you are not targetting Solaris 2.])
547      AC_MSG_WARN([=== Symbol versioning will be disabled.])
548      enable_symvers=no
549      ;;
550  esac
551fi
552
553# Check to see if libgcc_s exists, indicating that shared libgcc is possible.
554if test $enable_symvers != no; then
555  AC_MSG_CHECKING([for shared libgcc])
556  ac_save_CFLAGS="$CFLAGS"
557  CFLAGS=' -lgcc_s'
558  AC_TRY_LINK(, [return 0;], libat_shared_libgcc=yes, libat_shared_libgcc=no)
559  CFLAGS="$ac_save_CFLAGS"
560  if test $libat_shared_libgcc = no; then
561    cat > conftest.c <<EOF
562int main (void) { return 0; }
563EOF
564changequote(,)dnl
565    libat_libgcc_s_suffix=`${CC-cc} $CFLAGS $CPPFLAGS $LDFLAGS \
566			     -shared -shared-libgcc -o conftest.so \
567			     conftest.c -v 2>&1 >/dev/null \
568			     | sed -n 's/^.* -lgcc_s\([^ ]*\) .*$/\1/p'`
569changequote([,])dnl
570    rm -f conftest.c conftest.so
571    if test x${libat_libgcc_s_suffix+set} = xset; then
572      CFLAGS=" -lgcc_s$libat_libgcc_s_suffix"
573      AC_TRY_LINK(, [return 0;], libat_shared_libgcc=yes)
574      CFLAGS="$ac_save_CFLAGS"
575    fi
576  fi
577  AC_MSG_RESULT($libat_shared_libgcc)
578fi
579
580# For GNU ld, we need at least this version.  The format is described in
581# LIBAT_CHECK_LINKER_FEATURES above.
582libat_min_gnu_ld_version=21400
583# XXXXXXXXXXX libat_gnu_ld_version=21390
584
585# Check to see if unspecified "yes" value can win, given results above.
586# Change "yes" into either "no" or a style name.
587if test $enable_symvers != no && test $libat_shared_libgcc = yes; then
588  if test $with_gnu_ld = yes; then
589    if test $libat_gnu_ld_version -ge $libat_min_gnu_ld_version ; then
590      enable_symvers=gnu
591    elif test $libat_ld_is_gold = yes ; then
592      enable_symvers=gnu
593    else
594      # The right tools, the right setup, but too old.  Fallbacks?
595      AC_MSG_WARN(=== Linker version $libat_gnu_ld_version is too old for)
596      AC_MSG_WARN(=== full symbol versioning support in this release of GCC.)
597      AC_MSG_WARN(=== You would need to upgrade your binutils to version)
598      AC_MSG_WARN(=== $libat_min_gnu_ld_version or later and rebuild GCC.)
599      if test $libat_gnu_ld_version -ge 21200 ; then
600        # Globbing fix is present, proper block support is not.
601        dnl AC_MSG_WARN([=== Dude, you are soooo close.  Maybe we can fake it.])
602        dnl enable_symvers=???
603        AC_MSG_WARN([=== Symbol versioning will be disabled.])
604        enable_symvers=no
605      else
606        # 2.11 or older.
607        AC_MSG_WARN([=== Symbol versioning will be disabled.])
608        enable_symvers=no
609      fi
610    fi
611  elif test $enable_symvers = sun; then
612    : All interesting versions of Sun ld support sun style symbol versioning.
613  else
614    # just fail for now
615    AC_MSG_WARN([=== You have requested some kind of symbol versioning, but])
616    AC_MSG_WARN([=== either you are not using a supported linker, or you are])
617    AC_MSG_WARN([=== not building a shared libgcc_s (which is required).])
618    AC_MSG_WARN([=== Symbol versioning will be disabled.])
619    enable_symvers=no
620  fi
621fi
622if test $enable_symvers = gnu; then
623  AC_DEFINE(LIBAT_GNU_SYMBOL_VERSIONING, 1,
624	    [Define to 1 if GNU symbol versioning is used for libatomic.])
625fi
626
627AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB, test $enable_symvers != no)
628AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB_GNU, test $enable_symvers = gnu)
629AM_CONDITIONAL(LIBAT_BUILD_VERSIONED_SHLIB_SUN, test $enable_symvers = sun)
630AC_MSG_NOTICE(versioning on shared library symbols is $enable_symvers)
631])
632
633dnl ----------------------------------------------------------------------
634sinclude(../libtool.m4)
635sinclude(../config/enable.m4)
636sinclude(../config/cet.m4)
637dnl The lines below arrange for aclocal not to bring an installed
638dnl libtool.m4 into aclocal.m4, while still arranging for automake to
639dnl add a definition of LIBTOOL to Makefile.in.
640ifelse(,,,[AC_SUBST(LIBTOOL)
641AC_DEFUN([AM_PROG_LIBTOOL])
642AC_DEFUN([AC_LIBTOOL_DLOPEN])
643AC_DEFUN([AC_PROG_LD])
644])
645