csu/Makefile

   1 # Makefile for csu code for GNU C library.
   2 # Copyright (C) 1995-2018 Free Software Foundation, Inc.
   3 # This file is part of the GNU C Library.
   4
   5 # The GNU C Library is free software; you can redistribute it and/or
   6 # modify it under the terms of the GNU Lesser General Public
   7 # License as published by the Free Software Foundation; either
   8 # version 2.1 of the License, or (at your option) any later version.
   9
  10 # The GNU C Library is distributed in the hope that it will be useful,
  11 # but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 # Lesser General Public License for more details.
  14
  15 # You should have received a copy of the GNU Lesser General Public
  16 # License along with the GNU C Library; if not, see
  17 # <http://www.gnu.org/licenses/>.
  18
  19 # This directory contains the C startup code (that which calls main).  This
  20 # consists of the startfile, built from start.c and installed as crt0.o
  21 # (traditionally) or crt1.o (for ELF).  In ELF we also install crti.o and
  22 # crtn.o, special "initializer" and "finalizer" files used in the link
  23 # to make the .init and .fini sections work right.
  24
  25 subdir := csu
  26
  27 include ../Makeconfig
  28
  29 routines = init-first libc-start $(libc-init) sysdep version check_fds \
  30            libc-tls elf-init dso_handle
  31 aux      = errno
  32 elide-routines.os = libc-tls
  33 static-only-routines = elf-init
  34 csu-dummies = $(filter-out $(start-installed-name),crt1.o Mcrt1.o)
  35 extra-objs = start.o \
  36              $(start-installed-name) g$(start-installed-name) $(csu-dummies) \
  37              S$(start-installed-name)
  38 omit-deps = $(patsubst %.o,%,$(start-installed-name) g$(start-installed-name) \
  39                              b$(start-installed-name) $(csu-dummies) \
  40                              S$(start-installed-name) \
  41                              r$(start-installed-name) \
  42                              gr$(start-installed-name))
  43 install-lib = $(start-installed-name) g$(start-installed-name) $(csu-dummies)
  44
  45 # No tests are allowed in the csu/ subdirectory because the startup
  46 # code is compiled with special flags.
  47 tests =
  48
  49 CFLAGS-.o += $(no-stack-protector)
  50 CFLAGS-.op += $(no-stack-protector)
  51 CFLAGS-.os += $(no-stack-protector)
  52
  53 ifeq (yes,$(build-shared))
  54 extra-objs += S$(start-installed-name) gmon-start.os
  55 ifneq ($(start-installed-name),$(static-start-installed-name))
  56 extra-objs += gmon-start.o
  57 endif
  58 install-lib += S$(start-installed-name)
  59 generated += start.os
  60 else
  61 extra-objs += gmon-start.o
  62 endif
  63
  64 ifneq ($(start-installed-name),$(static-start-installed-name))
  65 # FIXME: Only Hurd defines static-start-installed-name.  Hurd needs to
  66 # provide special rules to support static PIE.
  67 extra-objs += $(static-start-installed-name) g$(static-start-installed-name)
  68 omit-deps += $(patsubst %.o,%,$(static-start-installed-name) \
  69                              g$(static-start-installed-name))
  70 install-lib += $(static-start-installed-name) g$(static-start-installed-name)
  71 else
  72 ifeq (yes,$(enable-static-pie))
  73 extra-objs += r$(start-installed-name) gr$(start-installed-name)
  74 install-lib += r$(start-installed-name) gr$(start-installed-name)
  75 endif
  76 endif
  77
  78 before-compile += $(objpfx)abi-tag.h
  79 generated += abi-tag.h
  80
  81 # These are the special initializer/finalizer files.  They are always the
  82 # first and last file in the link.  crti.o ... crtn.o define the global
  83 # "functions" _init and _fini to run the .init and .fini sections.
  84 crtstuff = crti crtn
  85
  86 install-lib += $(crtstuff:=.o)
  87 extra-objs += $(crtstuff:=.o)
  88
  89 ifneq ($(multidir),.)
  90 multilib-extra-objs = $(addprefix $(multidir)/, $(install-lib))
  91 extra-objs += $(multilib-extra-objs)
  92 endif
  93
  94 extra-objs += abi-note.o init.o static-reloc.o
  95 ifeq (yes,$(build-shared))
  96 extra-objs += static-reloc.os
  97 endif
  98 asm-CPPFLAGS += -I$(objpfx).
  99
 100 # Enable unwinding so backtrace unwinds to __libc_start_main
 101 CFLAGS-libc-start.c += -funwind-tables
 102
 103 include ../Rules
 104
 105 # Make these in the lib pass so they're available in time to link things with.
 106 subdir_lib: $(extra-objs:%=$(objpfx)%)
 107
 108 define link-relocatable
 109 $(CC) -nostdlib -nostartfiles -r -o $@ $^
 110 endef
 111
 112 ifndef start-installed-name-rule
 113 # We link the ELF startfile along with a SHT_NOTE section indicating
 114 # the kernel ABI the binaries linked with this library will require.
 115 $(objpfx)$(start-installed-name): $(objpfx)start.o $(objpfx)abi-note.o \
 116                                   $(objpfx)init.o $(objpfx)static-reloc.o
 117         $(link-relocatable)
 118 $(objpfx)r$(start-installed-name): $(objpfx)start.o $(objpfx)abi-note.o \
 119                                   $(objpfx)init.o
 120         $(link-relocatable)
 121 $(objpfx)S$(start-installed-name): $(objpfx)start.os $(objpfx)abi-note.o \
 122                                   $(objpfx)init.o
 123         $(link-relocatable)
 124 endif
 125
 126 # The profiling startfile is made by linking together the normal
 127 # startfile with gmon-start.o, which defines a constructor function
 128 # to turn on profiling code at startup.
 129 ifeq (yes,$(build-shared))
 130 $(objpfx)g$(start-installed-name): \
 131   $(objpfx)g%: $(objpfx)S% $(objpfx)gmon-start.os $(objpfx)static-reloc.os
 132         $(link-relocatable)
 133 $(objpfx)gr$(start-installed-name): \
 134   $(objpfx)gr%: $(objpfx)r% $(objpfx)gmon-start.o
 135         $(link-relocatable)
 136 ifneq ($(start-installed-name),$(static-start-installed-name))
 137 $(objpfx)g$(static-start-installed-name): \
 138   $(objpfx)g%: $(objpfx)% $(objpfx)gmon-start.o
 139         $(link-relocatable)
 140 endif
 141 else
 142 $(addprefix $(objpfx),$(sort g$(start-installed-name) \
 143                              g$(static-start-installed-name))): \
 144   $(objpfx)g%: $(objpfx)% $(objpfx)gmon-start.o
 145         $(link-relocatable)
 146 endif
 147
 148 # These extra files are sometimes expected by system standard linking
 149 # procedures, but we have nothing for them to do.  So compile empty files.
 150 $(addprefix $(objpfx),$(filter-out $(start-installed-name), $(csu-dummies))):\
 151   $(before-compile)
 152         $(COMPILE.c) -o $@ -x c /dev/null
 153
 154 # These headers are used by the startup code.
 155 $(objpfx)abi-tag.h: $(..)abi-tags
 156         $(make-target-directory)
 157         rm -f $@.new
 158         sed -e 's/#.*$$//' -e '/^[      ]*$$/d' $< | \
 159         while read conf tagos tagver; do \
 160           test `expr '$(config-machine)-$(config-vendor)-$(config-os)' \
 161                      : "$$conf"` != 0 || continue; \
 162           ( echo "$$tagos" | \
 163             sed -e 's/[^0-9xXa-fA-F     ]//' \
 164                 -e 's/^/#define __ABI_TAG_OS /'; \
 165             echo "#ifndef __ABI_TAG_VERSION"; \
 166             echo "$$tagver" | \
 167             sed -e 's/[^0-9xXa-fA-F]/ /g' -e 's/ *$$//' \
 168               -e 's/ /,/g' -e 's/^/# define __ABI_TAG_VERSION /'; \
 169             echo "#endif" ) > $@.new; \
 170         done
 171         if test -r $@.new; then mv -f $@.new $@; \
 172         else echo >&2 'This configuration not matched in $<'; exit 1; fi
 173
 174 ifneq ($(multidir),.)
 175 $(addprefix $(objpfx)$(multidir)/, $(install-lib)): $(addprefix $(objpfx), $(install-lib))
 176         $(make-link-multidir)
 177 endif