build: improve backtrace support/detection
libexecinfo is used to provide backtrace() on *BSD. The API is
compatible with glibc's, so this is a "free" improvement.
To improve configure behaviour, the following configure options are
modified/introduced:
* --enable-gcc-rdynamic now defaults to "on" if the compiler is gcc.
(I sadly wasn't able to find any documentation on the availability of
this option for llvm, even though at least the version I have
installed does support it)
* --enable-backtrace has been added. This behaves as off/auto/on
switch, i.e. giving either {dis,en}able will result in the requested
behaviour (or an error if support wasn't found)
Signed-off-by: David Lamparter <equinox@opensourcerouting.org>
diff --git a/INSTALL.quagga.txt b/INSTALL.quagga.txt
index 0d46587..11c85b1 100644
--- a/INSTALL.quagga.txt
+++ b/INSTALL.quagga.txt
@@ -31,6 +31,9 @@
OpenBSD ? [info needed on what should work]
Solaris (modern/supported versions, including OpenSolaris forks)
+On BSD systems, installing libexecinfo is strongly recommended in order
+to get backtrace support.
+
For further Quagga specific information on 'configure' and build-time
configuration of the software, please read the Quagga info
documentation, (doc/quagga.info). To read the info page included with
diff --git a/configure.ac b/configure.ac
index ff7a4d5..8964006 100755
--- a/configure.ac
+++ b/configure.ac
@@ -273,7 +273,9 @@
AC_ARG_ENABLE(linux24_tcp_md5,
[ --enable-linux24-tcp-md5 enable support for old, Linux-2.4 RFC2385 patch])
AC_ARG_ENABLE(gcc-rdynamic,
-[ --enable-gcc-rdynamic enable gcc linking with -rdynamic for better backtraces])
+[ --enable-gcc-rdynamic enable linking with -rdynamic for better backtraces (default if gcc)])
+AC_ARG_ENABLE(backtrace,
+[ --disable-backtrace, disable crash backtraces (default autodetect)])
AC_ARG_ENABLE(time-check,
[ --disable-time-check disable slow thread warning messages])
AC_ARG_ENABLE(pcreposix,
@@ -288,8 +290,10 @@
CFLAGS="${CFLAGS} -Wpacked -Wpadded"
fi
-if test x"${enable_gcc_rdynamic}" = x"yes" ; then
- LDFLAGS="${LDFLAGS} -rdynamic"
+if test x"${enable_gcc_rdynamic}" != x"no" ; then
+ if test x"${enable_gcc_rdynamic}" = x"yes" -o x"$COMPILER" = x"GCC"; then
+ LDFLAGS="${LDFLAGS} -rdynamic"
+ fi
fi
if test x"${enable_time_check}" != x"no" ; then
@@ -1566,12 +1570,21 @@
dnl ---------------------------
dnl check for glibc 'backtrace'
dnl ---------------------------
-AC_CHECK_HEADER([execinfo.h],
- [AC_CHECK_FUNC([backtrace],
- [AC_DEFINE(HAVE_GLIBC_BACKTRACE,,[Glibc backtrace])
- AC_DEFINE(HAVE_STACK_TRACE,,[Stack symbol decoding])
+if test x"${enable_backtrace}" != x"no" ; then
+ backtrace_ok=no
+ AC_CHECK_HEADER([execinfo.h], [
+ AC_SEARCH_LIBS([backtrace], [execinfo], [
+ AC_DEFINE(HAVE_GLIBC_BACKTRACE,,[Glibc backtrace])
+ AC_DEFINE(HAVE_STACK_TRACE,,[Stack symbol decoding])
+ backtrace_ok=yes
+ ],, [-lm])
])
-])
+
+ if test x"${enable_backtrace}" = x"yes" -a x"${backtrace_ok}" = x"no"; then
+ dnl user explicitly requested backtrace but we failed to find support
+ AC_MSG_FAILURE([failed to find backtrace support])
+ fi
+fi
dnl -----------------------------------------
dnl check for malloc mallinfo struct and call
diff --git a/doc/install.texi b/doc/install.texi
index 0f8f65f..1e8d965 100644
--- a/doc/install.texi
+++ b/doc/install.texi
@@ -96,6 +96,16 @@
minimally decrease compile time and overhead. They can always be built and
executed at a later time by running @command{make check} in the @file{tests/}
subdirectory, even if they're excluded from build.
+@item --enable-gcc-rdynamic
+Pass the @command{-rdynamic} option to the linker driver. This is in most
+cases neccessary for getting usable backtraces. This option defaults to on
+if the compiler is detected as gcc, but giving an explicit enable/disable is
+suggested.
+@item --enable-backtrace
+Controls backtrace support for the crash handlers. This is autodetected by
+default. Using the switch will enforce the requested behaviour, failing with
+an error if support is requested but not available. On BSD systems, this
+needs libexecinfo, while on glibc support for this is part of libc itself.
@end table
You may specify any combination of the above options to the configure