about summary refs log tree commit diff
path: root/csu/Makefile
blob: fd668a5d0092f7923e7aaa70883ea25fa2e99212 (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
# Makefile for csu code for GNU C library.
# Copyright (C) 1995-2017 Free Software Foundation, Inc.
# This file is part of the GNU C Library.

# The GNU C Library is free software; you can redistribute it and/or
# modify it under the terms of the GNU Lesser General Public
# License as published by the Free Software Foundation; either
# version 2.1 of the License, or (at your option) any later version.

# The GNU C Library 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
# Lesser General Public License for more details.

# You should have received a copy of the GNU Lesser General Public
# License along with the GNU C Library; if not, see
# <http://www.gnu.org/licenses/>.

# This directory contains the C startup code (that which calls main).  This
# consists of the startfile, built from start.c and installed as crt0.o
# (traditionally) or crt1.o (for ELF).	In ELF we also install crti.o and
# crtn.o, special "initializer" and "finalizer" files used in the link
# to make the .init and .fini sections work right.

subdir := csu

include ../Makeconfig

routines = init-first libc-start $(libc-init) sysdep version check_fds \
	   libc-tls elf-init dso_handle
aux	 = errno
elide-routines.os = libc-tls
static-only-routines = elf-init
csu-dummies = $(filter-out $(start-installed-name),crt1.o Mcrt1.o)
extra-objs = start.o \
	     $(start-installed-name) g$(start-installed-name) $(csu-dummies) \
	     S$(start-installed-name)
omit-deps = $(patsubst %.o,%,$(start-installed-name) g$(start-installed-name) \
			     b$(start-installed-name) $(csu-dummies) \
			     S$(start-installed-name))
install-lib = $(start-installed-name) g$(start-installed-name) $(csu-dummies)

# No tests are allowed in the csu/ subdirectory because the startup
# code is compiled with special flags.
tests =

CFLAGS-.o += $(no-stack-protector)
CFLAGS-.op += $(no-stack-protector)
CFLAGS-.os += $(no-stack-protector)

ifeq (yes,$(build-shared))
extra-objs += S$(start-installed-name) gmon-start.os
ifneq ($(start-installed-name),$(static-start-installed-name))
extra-objs += gmon-start.o
endif
install-lib += S$(start-installed-name)
generated += start.os
else
extra-objs += gmon-start.o
endif

ifneq ($(start-installed-name),$(static-start-installed-name))
extra-objs += $(static-start-installed-name) g$(static-start-installed-name)
omit-deps += $(patsubst %.o,%,$(static-start-installed-name) \
			     g$(static-start-installed-name))
install-lib += $(static-start-installed-name) g$(static-start-installed-name)
endif

before-compile += $(objpfx)abi-tag.h
generated += abi-tag.h

# These are the special initializer/finalizer files.  They are always the
# first and last file in the link.  crti.o ... crtn.o define the global
# "functions" _init and _fini to run the .init and .fini sections.
crtstuff = crti crtn

install-lib += $(crtstuff:=.o)
extra-objs += $(crtstuff:=.o)

extra-objs += abi-note.o init.o
asm-CPPFLAGS += -I$(objpfx).

# Enable unwinding so backtrace unwinds to __libc_start_main
CFLAGS-libc-start.c += -funwind-tables

include ../Rules

# Make these in the lib pass so they're available in time to link things with.
subdir_lib: $(extra-objs:%=$(objpfx)%)

define link-relocatable
$(CC) -nostdlib -nostartfiles -r -o $@ $^
endef

ifndef start-installed-name-rule
# We link the ELF startfile along with a SHT_NOTE section indicating
# the kernel ABI the binaries linked with this library will require.
$(objpfx)$(start-installed-name): $(objpfx)start.o $(objpfx)abi-note.o \
				  $(objpfx)init.o
	$(link-relocatable)
$(objpfx)S$(start-installed-name): $(objpfx)start.os $(objpfx)abi-note.o \
				  $(objpfx)init.o
	$(link-relocatable)
endif

# The profiling startfile is made by linking together the normal
# startfile with gmon-start.o, which defines a constructor function
# to turn on profiling code at startup.
ifeq (yes,$(build-shared))
$(objpfx)g$(start-installed-name): \
  $(objpfx)g%: $(objpfx)S% $(objpfx)gmon-start.os
	$(link-relocatable)
ifneq ($(start-installed-name),$(static-start-installed-name))
$(objpfx)g$(static-start-installed-name): \
  $(objpfx)g%: $(objpfx)% $(objpfx)gmon-start.o
	$(link-relocatable)
endif
else
$(addprefix $(objpfx),$(sort g$(start-installed-name) \
			     g$(static-start-installed-name))): \
  $(objpfx)g%: $(objpfx)% $(objpfx)gmon-start.o
	$(link-relocatable)
endif

# These extra files are sometimes expected by system standard linking
# procedures, but we have nothing for them to do.  So compile empty files.
$(addprefix $(objpfx),$(filter-out $(start-installed-name), $(csu-dummies))):\
  $(before-compile)
	$(COMPILE.c) -o $@ -x c /dev/null

# These headers are used by the startup code.
$(objpfx)abi-tag.h: $(..)abi-tags
	$(make-target-directory)
	rm -f $@.new
	sed -e 's/#.*$$//' -e '/^[	]*$$/d' $< | \
	while read conf tagos tagver; do \
	  test `expr '$(config-machine)-$(config-vendor)-$(config-os)' \
		     : "$$conf"` != 0 || continue; \
	  ( echo "$$tagos" | \
	    sed -e 's/[^0-9xXa-fA-F 	]//' \
		-e 's/^/#define __ABI_TAG_OS /'; \
	    echo "#ifndef __ABI_TAG_VERSION"; \
	    echo "$$tagver" | \
	    sed -e 's/[^0-9xXa-fA-F]/ /g' -e 's/ *$$//' \
	      -e 's/ /,/g' -e 's/^/# define __ABI_TAG_VERSION /'; \
	    echo "#endif" ) > $@.new; \
	done
	if test -r $@.new; then mv -f $@.new $@; \
	else echo >&2 'This configuration not matched in $<'; exit 1; fi