Make c-stack use libsigsegv, when available. * modules/c-stack (Depends-on): Add libsigsegv. * modules/c-stack-tests (Makefile.am): Link with libsigsegv, if needed. * lib/c-stack.c (SIGSTKSZ): Define fallback. (segv_handler, overflow_handler, c_stack_action) [HAVE_LIBSIGSEGV && !HAVE_XSI_STACK_OVERFLOW_HEURISTIC]: Add new implementation when libsigsegv is available, but only when using the library is necessary. * m4/c-stack.m4 (AC_SYS_XSI_STACK_OVERFLOW_HEURISTIC): Add comment, explaining why XSI check fails on Linux. (gl_PREREQ_C_STACK): Supply LIBCSTACK, LTLIBCSTACK. * tests/test-c-stack2.sh: Tweak skip message. * NEWS: Document new link-time requirements. Signed-off-by: Eric Blake <ebb9@byu.net>

Files:
tests/test-c-stack.c
tests/test-c-stack.sh
tests/test-c-stack2.sh

Depends-on:
exitfail

configure.ac:

Makefile.am:
TESTS += test-c-stack.sh test-c-stack2.sh
TESTS_ENVIRONMENT += EXEEXT='@EXEEXT@'
check_PROGRAMS += test-c-stack
test_c_stack_LDADD = $(LDADD) $(LIBCSTACK) @LIBINTL@
MOSTLYCLEANFILES += t-c-stack.tmp t-c-stack2.tmp