csu/Makefile

   1 # Makefile for csu code for GNU C library.
   2
   3 # Copyright (C) 1995 Free Software Foundation, Inc.
   4 # This file is part of the GNU C Library.
   5
   6 # The GNU C Library is free software; you can redistribute it and/or
   7 # modify it under the terms of the GNU Library General Public License
   8 # as published by the Free Software Foundation; either version 2 of
   9 # the License, or (at your option) any later version.
  10
  11 # The GNU C Library is distributed in the hope that it will be useful,
  12 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14 # Library General Public License for more details.
  15
  16 # You should have received a copy of the GNU Library General Public
  17 # License along with the GNU C Library; see the file COPYING.LIB.  If
  18 # not, write to the Free Software Foundation, Inc., 675 Mass Ave,
  19 # Cambridge, MA 02139, USA.
  20
  21 # This directory contains the C startup code (that which calls main).  This
  22 # consists of the startfile, built from start.c and installed as crt0.o
  23 # (traditionally) or crt1.o (for ELF); and some initialization code which
  24 # is in the C library itself.  In ELF we also install crti.o and crtn.o,
  25 # special "initializer" and "finalizer" files in used in the link to make
  26 # the .init and .fini sections work right; both these files are built (in
  27 # an arcane manner) from initfini.c.
  28
  29 subdir := csu
  30
  31 csu-dummies = $(filter-out $(start-installed-name),crt1.o Mcrt1.o)
  32 extra-objs = start.o $(start-installed-name) $(csu-dummies)
  33 omit-deps = $(patsubst %.o,%,$(start-installed-name) $(csu-dummies))
  34 install-lib = $(start-installed-name) $(csu-dummies)
  35 distribute = initfini.c
  36
  37 all: # Make this the default target; it will be defined in Rules.
  38
  39 include ../Makeconfig
  40
  41 ifneq ($(elf),yes)
  42
  43 # When not using ELF, there is just one startfile, called crt0.o.
  44 start-installed-name = crt0.o
  45
  46 else
  47
  48 # In the ELF universe, crt0.o is called crt1.o, and there are
  49 # some additional bizarre files.
  50 start-installed-name = crt1.o
  51
  52 # These are the special initializer/finalizer files.  They are always the
  53 # first and last file in the link.  crti.o ... crtn.o are used for normal
  54 # linking; they define the global "functions" _init and _fini to run the
  55 # .init and .fini sections.  crti_s.o ... crtn_s.o are for making shared
  56 # library objects; they put the prologue/epilogue code into the .init and
  57 # .fini sections, but define no global symbols.
  58 crtstuff = crti crtn crti_s crtn_s
  59
  60 install-lib += $(crtstuff:=.o)
  61 extra-objs += $(crtstuff:=.o)
  62 generated += $(crtstuff:=.s)
  63 omit-deps += $(crtstuff)
  64
  65 # Compile initfini.c to assembly code, which contains embedded shell
  66 # commands that prodice crti.s-new and crtn.s-new when run.  We need to
  67 # disable emission of .size directives and debugging information, since
  68 # they will get confused by the splitting of the output we do.
  69 $(objpfx)cr%i.s $(objpfx)cr%n.s: initfini.c; $(initfini)
  70 $(objpfx)cr%i_s.s $(objpfx)cr%n_s.s: initfini.c; $(initfini)
  71
  72 define initfini
  73 -rm -f $(objpfx)crtcommon.tmp
  74 (echo 'cat > crtcommon.tmp <<\EOF_common'; \
  75  $(CC) $< $(CPPFLAGS) $(CFLAGS) \
  76        $(patsubst %,-DGLOBAL=static,$(filter %_s.s,$@)) \
  77        -finhibit-size-directive -g0 -S -o -; \
  78  echo 'EOF_common') | (cd $(@D); $(SHELL))
  79 cat $(objpfx)crtcommon.tmp >> $(objpfx)crti.s-new
  80 cat $(objpfx)crtcommon.tmp >> $(objpfx)crtn.s-new
  81 rm -f $(objpfx)crtcommon.tmp
  82 mv -f $(objpfx)crti.s-new $(subst crtn,crti,$@)
  83 mv -f $(objpfx)crtn.s-new $(subst crti,crtn,$@)
  84 endef
  85
  86 endif
  87
  88 include ../Rules
  89
  90 # The startfile is installed under different names, so we just call our
  91 # source file `start.c' and copy to the installed name after compiling.
  92 $(objpfx)$(start-installed-name): $(objpfx)start.o
  93         -rm -f $@
  94         ln $< $@
  95
  96 # These extra files are sometimes expected by system standard linking
  97 # procedures, but we have nothing for them to do.  So compile empty files.
  98 $(addprefix $(objpfx),$(filter-out $(start-installed-name),$(csu-dummies))):
  99         cp /dev/null $(@:.o=.c)
 100         $(COMPILE.c) $(@:.o=.c) $(OUTPUT_OPTION)
 101         rm -f $(@:.o=.c)
 102