libstdc++-v3/src/experimental/Makefile.am

   1 ## Makefile for experimental additions to the GNU C++ Standard library.
   2 ##
   3 ## Copyright (C) 2014-2023 Free Software Foundation, Inc.
   4 ##
   5 ## Process this file with automake to produce Makefile.in.
   6 ##
   7 ## This file is part of GCC.
   8 ##
   9 ## GCC is free software; you can redistribute it and/or modify
  10 ## it under the terms of the GNU General Public License as published by
  11 ## the Free Software Foundation; either version 3, or (at your option)
  12 ## any later version.
  13 ##
  14 ## GCC 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
  20 ## along with GCC; see the file COPYING3.  If not see
  21 ## <http://www.gnu.org/licenses/>.
  22
  23 include $(top_srcdir)/fragment.am
  24
  25 toolexeclib_LTLIBRARIES = libstdc++exp.la
  26
  27 headers =
  28
  29 sources = \
  30         contract.cc
  31
  32 # vpath % $(top_srcdir)/src/experimental
  33
  34 libstdc__exp_la_SOURCES = $(sources)
  35
  36 # AM_CXXFLAGS needs to be in each subdirectory so that it can be
  37 # modified in a per-library or per-sub-library way.  Need to manually
  38 # set this option because CONFIG_CXXFLAGS has to be after
  39 # OPTIMIZE_CXXFLAGS on the compile line so that -O2 can be overridden
  40 # as the occasion calls for it.
  41 AM_CXXFLAGS = \
  42         -std=gnu++17 -nostdinc++ \
  43         $(glibcxx_lt_pic_flag) $(glibcxx_compiler_shared_flag) \
  44         $(XTEMPLATE_FLAGS) $(VTV_CXXFLAGS) \
  45         $(WARN_CXXFLAGS) $(OPTIMIZE_CXXFLAGS) $(CONFIG_CXXFLAGS) \
  46         -fimplicit-templates
  47
  48 AM_MAKEFLAGS = \
  49         "gxx_include_dir=$(gxx_include_dir)"
  50
  51 # Libtool notes
  52
  53 # 1) In general, libtool expects an argument such as `--tag=CXX' when
  54 # using the C++ compiler, because that will enable the settings
  55 # detected when C++ support was being configured.  However, when no
  56 # such flag is given in the command line, libtool attempts to figure
  57 # it out by matching the compiler name in each configuration section
  58 # against a prefix of the command line.  The problem is that, if the
  59 # compiler name and its initial flags stored in the libtool
  60 # configuration file don't match those in the command line, libtool
  61 # can't decide which configuration to use, and it gives up.  The
  62 # correct solution is to add `--tag CXX' to LTCXXCOMPILE and maybe
  63 # CXXLINK, just after $(LIBTOOL), so that libtool doesn't have to
  64 # attempt to infer which configuration to use.
  65 #
  66 # The second tag argument, `--tag disable-shared` means that libtool
  67 # only compiles each source once, for static objects. In actuality,
  68 # glibcxx_lt_pic_flag and glibcxx_compiler_shared_flag are added to
  69 # the libtool command that is used create the object, which is
  70 # suitable for shared libraries.  The `--tag disable-shared` must be
  71 # placed after --tag CXX lest things CXX undo the affect of
  72 # disable-shared.
  73
  74 # 2) Need to explicitly set LTCXXCOMPILE so that EXTRA_CXX_FLAGS is
  75 # last. (That way, things like -O2 passed down from the toplevel can
  76 # be overridden by --enable-debug.)
  77 LTCXXCOMPILE = \
  78         $(LIBTOOL) --tag CXX --tag disable-shared \
  79         $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
  80         --mode=compile $(CXX) $(TOPLEVEL_INCLUDES) \
  81         $(AM_CPPFLAGS) $(CPPFLAGS) $(AM_CXXFLAGS) $(CXXFLAGS) $(EXTRA_CXX_FLAGS)
  82
  83 LTLDFLAGS = $(shell $(SHELL) $(top_srcdir)/../libtool-ldflags $(LDFLAGS))
  84
  85 # 3) We'd have a problem when building the shared libstdc++ object if
  86 # the rules automake generates would be used.  We cannot allow g++ to
  87 # be used since this would add -lstdc++ to the link line which of
  88 # course is problematic at this point.  So, we get the top-level
  89 # directory to configure libstdc++-v3 to use gcc as the C++
  90 # compilation driver.
  91 CXXLINK = \
  92         $(LIBTOOL) --tag CXX --tag disable-shared \
  93         $(AM_LIBTOOLFLAGS) $(LIBTOOLFLAGS) \
  94         --mode=link $(CXX) \
  95         $(VTV_CXXLINKFLAGS) \
  96         $(OPT_LDFLAGS) $(SECTION_LDFLAGS) $(AM_CXXFLAGS) $(LTLDFLAGS) -o $@