Replace with IS_IN and IS_IN_LIB macros instead. This change results
in a change in generated code, because it fixes a subtle bug. The bug
was introduced when systemtap probes were added to lowlevellock.h,
which resulted in stap-probe.h being included in a number of places.
stap-probe.h always defines IN_LIB, which breaks a check in errno.h
and netdb.h since they rely on that macro to decide whether to
implement an internal version of a declaration or an external one.
The components that see a code change due to this are:
iconv_prog
libmemusage.so
libpcprofile.so
libSegFault.so
libutil.so.1
locale
localedef
nscd
All other built components (i.e. libc, libpthread, etc.) remain
unchanged by this on x86_64.
* elf/Makefile (CPPFLAGS-.os): Remove IN_LIB.
* elf/rtld-Rules (rtld-CPPFLAGS): Likewise.
* extra-lib.mk (CPPFLAGS-$(lib)): Likewise.
* include/libc-symbols.h (IS_IN_LIB): New macro.
* include/errno.h: Use IS_IN_LIB instead of IN_LIB.
* include/netdb.h: Likewise.
* include/stap-probe.h: Remove all uses of IN_LIB.
Define MODULE_NAME in the build command and define IN_MODULE using
MODULE_NAME. Verified that the generated code is unchanged on x86_64.
* Makeconfig (module-cppflags-real): Define MODULE_NAME
instead of IN_MODULE.
* include/libc-symbols.h (IN_MODULE): Define using
MODULE_NAME.
(PASTE_NAME, PASTE_NAME1): New macros.
* include/stap-probe.h (LIBC_PROBE_1): Use MODULE_NAME instead
of IN_LIB.
(STAP_PROBE_ASM): Likewise.
Add a comment pointing to the SystemTap wiki page that documents the
format of the arguments. Also add a pointer to the SystemTap and
gdb sources which seem to be the best place to get the architecture
specific details.
ChangeLog:
2014-02-11 Will Newton <will.newton@linaro.org>
* include/stap-probe.h: Add comment about probe argument
format.
Joseph pointed out in the bug report (and in an earlier thread) that
systemtap probes cause build time warnings like the following:
../sysdeps/ieee754/dbl-64/e_atan2.c:602:4: warning: the address of
'p' will always evaluate as 'true' [-Waddress]
due to the fact that we're now passing non-weak variables to
LIBC_PROBE in the libm probes. This happens only on configurations
that do not enable systemtap. The macro definition of LIBC_PROBE in
this case only acts as a sanity checker to ensure that the number
parameters passed to LIBC_PROBE is equal to the argument count
parameter passed before it. This can be done in a much simpler manner
by just adding a macro definition for each number of arguments. I am
assuming here that we don't really want to bother with supporting
LIBC_PROBE with an indeterminate number of arguments and if there is a
need for a probe to have more data than what is currently supported (4
arguments), one could simply add an additional macro here.
