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
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
|
# Makefile for csu code for GNU C library.
# Copyright (C) 1995-2019 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
# <https://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) \
r$(start-installed-name) \
gr$(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)
# Dummy object not actually used for anything. It is linked into
# crt1.o nevertheless, which in turn is statically linked into
# applications, so that build flags matter.
# See <https://sourceware.org/ml/libc-alpha/2018-07/msg00101.html>.
# NB: Using $(stack-protector) in this way causes a wrong definition
# STACK_PROTECTOR_LEVEL due to the preceding $(no-stack-protector),
# but it does not matter for this source file.
CFLAGS-static-reloc.os += $(stack-protector)
# This file is not actually part of the startup code in the nonshared
# case and statically linked into applications. See
# <https://sourceware.org/bugzilla/show_bug.cgi?id=23323>,
# <https://sourceware.org/ml/libc-alpha/2018-06/msg00717.html>.
# Also see the note above regarding STACK_PROTECTOR_LEVEL.
CFLAGS-elf-init.oS += $(stack-protector)
ifeq (yes,$(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))
# FIXME: Only Hurd defines static-start-installed-name. Hurd needs to
# provide special rules to support static PIE.
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)
else
ifeq (yes,$(enable-static-pie))
extra-objs += r$(start-installed-name) gr$(start-installed-name)
install-lib += r$(start-installed-name) gr$(start-installed-name)
endif
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 += $(crtstuff:=.o)
ifneq ($(multidir),.)
multilib-extra-objs = $(addprefix $(multidir)/, $(install-lib))
extra-objs += $(multilib-extra-objs)
endif
extra-objs += abi-note.o init.o static-reloc.o
ifeq (yes,$(build-shared))
extra-objs += static-reloc.os
endif
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 $(objpfx)static-reloc.o
$(link-relocatable)
$(objpfx)r$(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 $(objpfx)static-reloc.os
$(link-relocatable)
$(objpfx)gr$(start-installed-name): \
$(objpfx)gr%: $(objpfx)r% $(objpfx)gmon-start.o
$(link-relocatable)
ifneq ($(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 $<'; exit 1; fi
ifneq ($(multidir),.)
$(addprefix $(objpfx)$(multidir)/, $(install-lib)): $(addprefix $(objpfx), $(install-lib))
$(make-link-multidir)
endif
|
