This change augments the comment attached to the use of auto-host.h
in vxcrtstuff.c to better describe the reason for including it and
for the associated series of #undef directives.
It also augments the comment on dso_handle and removes a redundant
guard on HAVE_INITFINI_ARRAY_SUPPORT for the shared version of the
objects, nested within a section guarded on USE_INITFINI_ARRAY.
2022-09-29 Olivier Hainque <hainque@adacore.com>
libgcc/
* config/vxcrtstuff.c: Improve the comment attached to the use
of auto-host.h and of __dso_handle. Remove redundant guard on
HAVE_INITFINI_ARRAY_SUPPORT within a USE_INITFINI_ARRAY section.
This change tightens and documents the use of libc_internal, then
strengthens the VxWorks crtstuff objects for the support of shared
libraries. In particular:
- Define __dso_handle, which libstdc++.so requires,
- Provide _init and _fini functions to run through the init/fini arrays
for shared libs in configurations which HAVE_INITFINI_ARRAY_SUPPORT.
The init/fini functions are provided by libc_internal.a for static links
but with slightly different names and we don't want to risk dragging other
libc_internal contents in the closure accidentally so make sure we don't
link with it.
As for the !vxworks crtstuff, the new shared libs specific bits are
conditioned by a CRTSTUFFS_O macro, for which we provide new Makefile
fragment.
The bits to actually use the fragment and the shared objects will
be added by a forthcoming change, as part of a more general configury
update for shared libs.
The change also adds guards the eh table registration code
in vxcrtstuff so the objects can be used for either init/fini
or eh tables independently.
2021-12-07 Fred Konrad <konrad@adacore.com>
Olivier Hainque <hainque@adacore.com>
gcc/
* config/vxworks.h (VXWORKS_BASE_LIBS_RTP): Guard -lc_internal
on !shared+!non-static and document.
(VXWORKS_LIB_SPEC): Remove the bits intended to drag the
init/fini functions from libc_internal in the shared lib case.
(VX_CRTBEGIN_SPEC/VX_CRTEND_SPEC): Use vxcrtstuff objects also in
configurations with shared lib and INITFINI_ARRAY support.
libgcc/
* config/t-vxcrtstuffS: New Makefile fragment.
* config/vxcrtstuff.c: Provide __dso_handle. Provide _init/_fini
functions for INITFINI_ARRAY support in shared libs and guard
the definition of eh table registration functions on conditions
indicating they are needed.
When the translation unit itself creates pointers to the ctors/dtors
in a specific section handled by the linker (whether .init_array or
.ctors.*), there's no reason for the functions to have external
linkage. That ends up polluting the symbol table in the running
kernel.
This makes vxcrtstuff.c on par with the generic crtstuff.c which also
defines e.g. frame_dummy and __do_global_dtors_aux static.
libgcc/
* config/vxcrtstuff.c: Make constructor and destructor
functions static when possible.
These declarations prevent the priority given in the
constructor/destructor attributes from taking effect, thus emitting
the function pointers in the ordinary (lowest-priority)
.init_array/.fini_array sections.
libgcc/
* config/vxcrtstuff.c: Remove constructor/destructor
declarations.
When vxcrtstuff.c was created, the set of #includes was copied from
crtstuff.c. But crtstuff.c also has a bunch of #undefs after the first
#include, because, as the comment says, including auto-host.h when
building objects that are meant for target is technically not
correct.
This manifests when I try do do a canadian cross, with build=linux,
host=windows and target=vxworks, in that we pick up a
#define caddr_t char *
from auto-host.h, which then of course creates a problem when we later
include a target header that has
typedef char * caddr_t;
I assume that the #undefs in crtstuff.c have been added for similar
reasons.
These potentially problematic #defines all seem to be guarded by
#ifndef USED_FOR_TARGET, which tconfig.h defines before including
auto-host.h. So at first, it seems that one could avoid the problem
by simply removing the initial include of auto-host.h. Unfortunately,
we do need some of the things defined in auto-host.h within such an
ifndef USED_FOR_TARGET, namely the define of
HAVE_INITFINI_ARRAY_SUPPORT, which is what later causes
initfini-array.h to define USE_INITFINI_ARRAY. So as the next best
fix, just copy the #undefs from crtstuff.c.
libgcc/
* config/vxcrtstuff.c: Undefine caddr_t, pid_t, rlim_t,
ssize_t and vfork after including auto-host.h.
2019-11-06 Jerome Lambourg <lambourg@adacore.com>
Olivier Hainque <hainque@adacore.com>
libgcc/
* config/vxcrtstuff.c: New file.
* config/t-vxcrtstuff: New Makefile fragment.
* config.host: Append t-vxcrtstuff to the tmake_file list
on all VxWorks ports using dwarf for table based EH.
gcc/
* config/vx-common.h (USE_TM_CLONE_REGISTRY): Remove
definition, pointless with a VxWorks specific version
of crtstuff.
(DWARF2_UNWIND_INFO): Conditionalize on !ARM_UNWIND_INFO.
* config/vxworks.h (VX_CRTBEGIN_SPEC, VX_CRTEND_SPEC):
New local macros, controlling the addition of vxworks specific
crtstuff objects depending on the EH mechanism and kind of
module being linked.
(VXWORKS_STARTFILE_SPEC, VXWORKS_ENDFILE_SPEC): Use them.
Co-Authored-By: Olivier Hainque <hainque@adacore.com>
From-SVN: r278248
