gcc/libstdc++-v3/libsupc++/Makefile.am
Jonathan Wakely 637e3668fd libstdc++: Allow emergency EH alloc pool size to be tuned [PR68606]
Implement a long-standing request to support tuning the size of the
emergency buffer for allocating exceptions after malloc fails, or to
disable that buffer entirely.

It's now possible to disable the dynamic allocation of the buffer and
use a fixed-size static buffer, via --enable-libstdcxx-static-eh-pool.
This is a built-time choice that is baked into libstdc++ and so affects
all code linked against that build of libstdc++.

The size of the pool can be set by --with-libstdcxx-eh-pool-obj-count=N
which is measured in units of sizeof(void*) not bytes. A given exception
type such as std::system_error depends on the target, so giving a size
in bytes wouldn't be portable across 16/32/64-bit targets.

When libstdc++ is configured to use a dynamic buffer, the size of that
buffer can now be tuned at runtime by setting the GLIBCXX_TUNABLES
environment variable (c.f. PR libstdc++/88264). The number of exceptions
to reserve space for is controlled by the "glibcxx.eh_pool.obj_count"
and "glibcxx.eh_pool.obj_size" tunables. The pool will be sized to be
able to allocate obj_count exceptions of size obj_size*sizeof(void*) and
obj_count "dependent" exceptions rethrown by std::rethrow_exception.

With the ability to tune the buffer size, we can reduce the default pool
size on 32-bit and 16-bit targets. Most users never need to throw 1kB
exceptions in parallel from hundreds of threads after malloc is OOM. The
users who do need that can use the tunables to select larger sizes.

The old defaults can be chosen at runtime by setting GLIBCXX_TUNABLES
to:
64-bit: glibcxx.eh_pool.obj_count=64:glibcxx.eh_pool.obj_size=112
32-bit: glibcxx.eh_pool.obj_count=32:glibcxx.eh_pool.obj_size=104

Or approximated by configuring with:
64-bit: --with-libstdcxx-eh-pool-obj-count=252
32-bit: --with-libstdcxx-eh-pool-obj-count=94

libstdc++-v3/ChangeLog:

	PR libstdc++/68606
	* Makefile.in: Regenerate.
	* acinclude.m4 (GLIBCXX_EMERGENCY_EH_ALLOC): New macro.
	* configure: Regenerate.
	* configure.ac: Use GLIBCXX_EMERGENCY_EH_ALLOC.
	* crossconfig.m4: Check for secure_getenv.
	* doc/Makefile.in: Regenerate.
	* doc/xml/manual/configure.xml: Document new configure options.
	* doc/xml/manual/evolution.xml: Document addition of tunables.
	* doc/xml/manual/using_exceptions.xml: Document emergency
	buffer and tunables.
	* doc/html/*: Regenerate.
	* include/Makefile.in: Regenerate.
	* libsupc++/Makefile.am: Use EH_POOL_FLAGS.
	* libsupc++/Makefile.in: Regenerate.
	* libsupc++/eh_alloc.cc (EMERGENCY_OBJ_SIZE): Define in units
	of sizeof(void*) not including the ABI's exception header.
	(EMERGENCY_OBJ_COUNT): Define as target-independent calculation
	based on word size.
	(MAX_OBJ_COUNT): Define macro for upper limit on pool size.
	(pool) [_GLIBCXX_EH_POOL_STATIC]: Use fixed-size buffer.
	(pool::buffer_size_in_bytes): New static member function.
	(pool::pool): Parse GLIBCXX_TUNABLES environment variable to set
	pool size at runtime.
	(pool::in_pool): Use std::less<void*> for total order.
	(__freeres) [_GLIBCXX_EH_POOL_STATIC]: Do nothing.
	(__cxa_free_exception, __cxa_free_dependent_exception): Add
	[[unlikely]] attributes.
	* po/Makefile.in: Regenerate.
	* python/Makefile.in: Regenerate.
	* src/Makefile.in: Regenerate.
	* src/c++11/Makefile.in: Regenerate.
	* src/c++17/Makefile.in: Regenerate.
	* src/c++20/Makefile.in: Regenerate.
	* src/c++98/Makefile.in: Regenerate.
	* src/filesystem/Makefile.in: Regenerate.
	* src/libbacktrace/Makefile.in: Regenerate.
	* testsuite/Makefile.in: Regenerate.
2022-10-11 16:21:48 +01:00

252 lines
7.8 KiB
Makefile

## Makefile for the GNU C++ Support library.
##
## Copyright (C) 2000-2022 Free Software Foundation, Inc.
##
## Process this file with automake to produce Makefile.in.
##
## This file is part of GCC.
##
## GCC is free software; you can redistribute it and/or modify
## it under the terms of the GNU General Public License as published by
## the Free Software Foundation; either version 3, or (at your option)
## any later version.
##
## GCC is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with GCC; see the file COPYING3. If not see
## <http://www.gnu.org/licenses/>.
include $(top_srcdir)/fragment.am
# Need this library to both be part of libstdc++.a, and installed
# separately too.
# 1) separate libsupc++.la
toolexeclib_LTLIBRARIES = libsupc++.la
# 2) integrated libsupc++convenience.la that is to be a part of libstdc++.a
noinst_LTLIBRARIES = libsupc++convenience.la
std_HEADERS = \
compare cxxabi.h exception initializer_list new typeinfo
bits_HEADERS = \
atomic_lockfree_defines.h cxxabi_forced.h \
exception_defines.h exception_ptr.h hash_bytes.h nested_exception.h exception.h cxxabi_init_exception.h
headers = $(std_HEADERS) $(bits_HEADERS)
if GLIBCXX_HOSTED
c_sources = \
cp-demangle.c
endif
sources = \
array_type_info.cc \
atexit_arm.cc \
atexit_thread.cc \
atomicity.cc \
bad_alloc.cc \
bad_array_length.cc \
bad_array_new.cc \
bad_cast.cc \
bad_typeid.cc \
class_type_info.cc \
del_op.cc \
del_ops.cc \
del_opnt.cc \
del_opv.cc \
del_opvs.cc \
del_opvnt.cc \
dyncast.cc \
eh_alloc.cc \
eh_arm.cc \
eh_aux_runtime.cc \
eh_call.cc \
eh_catch.cc \
eh_exception.cc \
eh_globals.cc \
eh_personality.cc \
eh_ptr.cc \
eh_term_handler.cc \
eh_terminate.cc \
eh_tm.cc \
eh_throw.cc \
eh_type.cc \
eh_unex_handler.cc \
enum_type_info.cc \
function_type_info.cc \
fundamental_type_info.cc \
guard.cc \
guard_error.cc \
hash_bytes.cc \
nested_exception.cc \
new_handler.cc \
new_op.cc \
new_opnt.cc \
new_opv.cc \
new_opvnt.cc \
new_opa.cc \
new_opant.cc \
new_opva.cc \
new_opvant.cc \
del_opa.cc \
del_opant.cc \
del_opsa.cc \
del_opva.cc \
del_opvant.cc \
del_opvsa.cc \
pbase_type_info.cc \
pmem_type_info.cc \
pointer_type_info.cc \
pure.cc \
si_class_type_info.cc \
tinfo.cc \
tinfo2.cc \
vec.cc \
vmi_class_type_info.cc \
vterminate.cc
if ENABLE_VTABLE_VERIFY
if !VTV_CYGMIN
vtv_sources = \
vtv_stubs.cc
endif
endif
libsupc___la_SOURCES = $(sources) $(c_sources) $(vtv_sources)
libsupc__convenience_la_SOURCES = $(sources) $(c_sources) $(vtv_sources)
cp-demangle.c:
rm -f $@
$(LN_S) $(toplevel_srcdir)/libiberty/cp-demangle.c $@
cp-demangle.lo: cp-demangle.c
$(LTCOMPILE) -DIN_GLIBCPP_V3 -Wno-error -c $<
cp-demangle.o: cp-demangle.c
$(C_COMPILE) -DIN_GLIBCPP_V3 -Wno-error -c $<
atomicity_file = ${glibcxx_srcdir}/$(ATOMICITY_SRCDIR)/atomicity.h
atomicity.cc: ${atomicity_file}
$(LN_S) ${atomicity_file} ./atomicity.cc || true
# AM_CXXFLAGS needs to be in each subdirectory so that it can be
# modified in a per-library or per-sub-library way. Need to manually
# set this option because CONFIG_CXXFLAGS has to be after
# OPTIMIZE_CXXFLAGS on the compile line so that -O2 can be overridden
# as the occasion call for it.
AM_CXXFLAGS = \
$(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
$(XTEMPLATE_FLAGS) $(FREESTANDING_FLAGS) $(EH_POOL_FLAGS) \
$(WARN_CXXFLAGS) $(OPTIMIZE_CXXFLAGS) $(CONFIG_CXXFLAGS)
AM_MAKEFLAGS = \
"gxx_include_dir=$(gxx_include_dir)"
# Use special rules for pulling things out of libiberty. These
# objects should be compiled with the "C" compiler, not the C++
# compiler, and also should not use the C++ includes.
C_INCLUDES = -I.. -I$(toplevel_srcdir)/libiberty -I$(toplevel_srcdir)/include
C_COMPILE = \
$(CC) $(DEFS) $(C_INCLUDES) \
$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS)
# LTCOMPILE is copied from LTCXXCOMPILE below.
LTCOMPILE = $(LIBTOOL) --tag CC --tag disable-shared $(LIBTOOLFLAGS) --mode=compile \
$(CC) $(DEFS) $(C_INCLUDES) \
$(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CFLAGS) $(CFLAGS) $(EXTRA_CFLAGS)
# Libtool notes
# 1) In general, libtool expects an argument such as `--tag=CXX' when
# using the C++ compiler, because that will enable the settings
# detected when C++ support was being configured. However, when no
# such flag is given in the command line, libtool attempts to figure
# it out by matching the compiler name in each configuration section
# against a prefix of the command line. The problem is that, if the
# compiler name and its initial flags stored in the libtool
# configuration file don't match those in the command line, libtool
# can't decide which configuration to use, and it gives up. The
# correct solution is to add `--tag CXX' to LTCXXCOMPILE and maybe
# CXXLINK, just after $(LIBTOOL), so that libtool doesn't have to
# attempt to infer which configuration to use.
#
# The second tag argument, `--tag disable-shared` means that libtool
# only compiles each source once, for static objects. In actuality,
# glibcxx_lt_pic_flag and glibcxx_compiler_shared_flag are added to
# the libtool command that is used create the object, which is
# suitable for shared libraries. The `--tag disable-shared` must be
# placed after --tag CXX lest things CXX undo the affect of
# disable-shared.
# 2) Need to explicitly set LTCXXCOMPILE so that EXTRA_CXX_FLAGS is
# last. (That way, things like -O2 passed down from the toplevel can
# be overridden by --enable-debug.)
LTCXXCOMPILE = \
$(LIBTOOL) --tag CXX --tag disable-shared \
$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
--mode=compile $(CXX) $(TOPLEVEL_INCLUDES) \
$(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS) $(EXTRA_CXX_FLAGS)
LTLDFLAGS = $(shell $(SHELL) $(top_srcdir)/../libtool-ldflags $(LDFLAGS))
# 3) We'd have a problem when building the shared libstdc++ object if
# the rules automake generates would be used. We cannot allow g++ to
# be used since this would add -lstdc++ to the link line which of
# course is problematic at this point. So, we get the top-level
# directory to configure libstdc++-v3 to use gcc as the C++
# compilation driver.
CXXLINK = \
$(LIBTOOL) --tag CXX --tag disable-shared \
$(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
--mode=link $(CXX) \
$(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@
# Install notes
# We have to have rules modified from the default to counteract SUN make
# prepending each of $(*_HEADERS) with VPATH below.
stddir = $(gxx_include_dir)
bitsdir = $(gxx_include_dir)/bits
install-stdHEADERS: $(std_HEADERS)
@$(NORMAL_INSTALL)
$(mkinstalldirs) $(DESTDIR)$(stddir)
@list='$(std_HEADERS)'; for p in $$list; do \
q=`echo $$p | sed -e 's,.*/,,'`; \
if test -f "$$p"; then d= ; else d="$(srcdir)/"; fi; \
echo " $(INSTALL_DATA) $$d$$p $(DESTDIR)$(stddir)/$$q"; \
$(INSTALL_DATA) $$d$$p $(DESTDIR)$(stddir)/$$q; \
done
install-bitsHEADERS: $(bits_HEADERS)
@$(NORMAL_INSTALL)
$(mkinstalldirs) $(DESTDIR)$(bitsdir)
@list='$(bits_HEADERS)'; for p in $$list; do \
q=`echo $$p | sed -e 's,.*/,,'`; \
if test -f "$$p"; then d= ; else d="$(srcdir)/"; fi; \
echo " $(INSTALL_DATA) $$d$$p $(DESTDIR)$(bitsdir)/$$q"; \
$(INSTALL_DATA) $$d$$p $(DESTDIR)$(bitsdir)/$$q; \
done
uninstall-stdHEADERS:
@$(NORMAL_UNINSTALL)
list='$(std_HEADERS)'; for p in $$list; do \
q=`echo $$p | sed -e 's,.*/,,'`; \
rm -f $(DESTDIR)$(stddir)/$$q; \
done
uninstall-bitsHEADERS:
@$(NORMAL_UNINSTALL)
list='$(bits_HEADERS)'; for p in $$list; do \
q=`echo $$p | sed -e 's,.*/,,'`; \
rm -f $(DESTDIR)$(bitsdir)/$$q; \
done
# By adding these files here, automake will remove them for 'make clean'
CLEANFILES = stamp-*