1## Makefile for the C++20 sources of the GNU C++ Standard library. 2## 3## Copyright (C) 1997-2021 Free Software Foundation, Inc. 4## 5## This file is part of the libstdc++ version 3 distribution. 6## Process this file with automake to produce Makefile.in. 7 8## This file is part of the GNU ISO C++ Library. This library is free 9## software; you can redistribute it and/or modify it under the 10## terms of the GNU General Public License as published by the 11## Free Software Foundation; either version 3, or (at your option) 12## any later version. 13 14## This library is distributed in the hope that it will be useful, 15## but WITHOUT ANY WARRANTY; without even the implied warranty of 16## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 17## GNU General Public License for more details. 18 19## You should have received a copy of the GNU General Public License along 20## with this library; see the file COPYING3. If not see 21## <http://www.gnu.org/licenses/>. 22 23include $(top_srcdir)/fragment.am 24 25# Convenience library for C++17 runtime. 26noinst_LTLIBRARIES = libc++20convenience.la 27 28headers = 29 30if ENABLE_EXTERN_TEMPLATE 31# XTEMPLATE_FLAGS = -fno-implicit-templates 32inst_sources = \ 33 sstream-inst.cc 34else 35# XTEMPLATE_FLAGS = 36inst_sources = 37endif 38 39sources = 40 41vpath % $(top_srcdir)/src/c++20 42 43libc__20convenience_la_SOURCES = $(sources) $(inst_sources) 44 45# AM_CXXFLAGS needs to be in each subdirectory so that it can be 46# modified in a per-library or per-sub-library way. Need to manually 47# set this option because CONFIG_CXXFLAGS has to be after 48# OPTIMIZE_CXXFLAGS on the compile line so that -O2 can be overridden 49# as the occasion calls for it. 50AM_CXXFLAGS = \ 51 -std=gnu++20 \ 52 $(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \ 53 $(XTEMPLATE_FLAGS) $(VTV_CXXFLAGS) \ 54 $(WARN_CXXFLAGS) $(OPTIMIZE_CXXFLAGS) $(CONFIG_CXXFLAGS) \ 55 -fimplicit-templates 56 57AM_MAKEFLAGS = \ 58 "gxx_include_dir=$(gxx_include_dir)" 59 60# Libtool notes 61 62# 1) In general, libtool expects an argument such as `--tag=CXX' when 63# using the C++ compiler, because that will enable the settings 64# detected when C++ support was being configured. However, when no 65# such flag is given in the command line, libtool attempts to figure 66# it out by matching the compiler name in each configuration section 67# against a prefix of the command line. The problem is that, if the 68# compiler name and its initial flags stored in the libtool 69# configuration file don't match those in the command line, libtool 70# can't decide which configuration to use, and it gives up. The 71# correct solution is to add `--tag CXX' to LTCXXCOMPILE and maybe 72# CXXLINK, just after $(LIBTOOL), so that libtool doesn't have to 73# attempt to infer which configuration to use. 74# 75# The second tag argument, `--tag disable-shared` means that libtool 76# only compiles each source once, for static objects. In actuality, 77# glibcxx_lt_pic_flag and glibcxx_compiler_shared_flag are added to 78# the libtool command that is used create the object, which is 79# suitable for shared libraries. The `--tag disable-shared` must be 80# placed after --tag CXX lest things CXX undo the affect of 81# disable-shared. 82 83# 2) Need to explicitly set LTCXXCOMPILE so that EXTRA_CXX_FLAGS is 84# last. (That way, things like -O2 passed down from the toplevel can 85# be overridden by --enable-debug.) 86LTCXXCOMPILE = \ 87 $(LIBTOOL) --tag CXX --tag disable-shared \ 88 $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \ 89 --mode=compile $(CXX) $(TOPLEVEL_INCLUDES) \ 90 $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS) $(EXTRA_CXX_FLAGS) 91 92LTLDFLAGS = $(shell $(SHELL) $(top_srcdir)/../libtool-ldflags $(LDFLAGS)) 93 94# 3) We'd have a problem when building the shared libstdc++ object if 95# the rules automake generates would be used. We cannot allow g++ to 96# be used since this would add -lstdc++ to the link line which of 97# course is problematic at this point. So, we get the top-level 98# directory to configure libstdc++-v3 to use gcc as the C++ 99# compilation driver. 100CXXLINK = \ 101 $(LIBTOOL) --tag CXX --tag disable-shared \ 102 $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \ 103 --mode=link $(CXX) \ 104 $(VTV_CXXLINKFLAGS) \ 105 $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@ 106