1# Subroutine makefile for compiling libc modules linked into dynamic linker.
2
3# Copyright (C) 2002-2022 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 Lesser General Public
8# License as published by the Free Software Foundation; either
9# version 2.1 of 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# Lesser General Public License for more details.
15
16# You should have received a copy of the GNU Lesser General Public
17# License along with the GNU C Library; if not, see
18# <https://www.gnu.org/licenses/>.
19
20# This makefile is never used by itself, but only from the rtld-libc.a
21# rule in Makefile, which does make -f librtld.mk -f rtld-Rules.
22# librtld.mk is the generated file containing variable definitions for
23# `rtld-subdirs', a subset of the top-level $(subdirs) list; and for each
24# SUBDIR in $(rtld-subdirs), `rtld-SUBDIR' listing `module.os' file names.
25
26.PHONY: rtld-all
27rtld-all:
28
29# When run from the elf/Makefile to build rtld-libc.a, $(subdir) is elf.
30ifneq ($(subdir),elf)
31ifndef rtld-modules
32$(error rtld-modules not set)
33endif
34endif
35
36ifndef rtld-modules
37# Running to build rtld-libc.a, driving runs of $(rtld-subdir-make), below.
38
39ifndef rtld-subdirs
40$(error This makefile is a subroutine of elf/Makefile not to be used directly)
41endif
42
43include ../Makeconfig
44
45rtld-all: $(objpfx)rtld-libc.a
46
47$(objpfx)rtld-libc.a: $(foreach dir,$(rtld-subdirs),\
48				$(addprefix $(common-objpfx)$(dir)/rtld-,\
49					    $(rtld-$(dir))))
50	@-rm -f $@T
51	$(AR) cq$(verbose) $@T $^
52	mv -f $@T $@
53
54# Use the verbose option of ar and tar when not running silently.
55ifeq	"$(findstring s,$(MAKEFLAGS))" ""	# if not -s
56verbose := v
57else						# -s
58verbose	:=
59endif						# not -s
60
61
62# For each subdirectory, define a pattern rule that makes all of that
63# subdirectory's modules at once with one recursive make command.
64object-suffixes-left := $(rtld-subdirs)
65define o-iterator-doit
66$(foreach obj,$(rtld-$o),$(common-objpfx)%/rtld-$(obj)): FORCE ; \
67	+$$(rtld-subdir-make)
68endef
69include $(patsubst %,../o-iterator.mk,$(object-suffixes-left))
70
71# This is how we descend into each subdirectory.  See below.
72define rtld-subdir-make
73$(MAKE) $(subdir-args) objdir=$(objdir) \
74	-f Makefile -f ../elf/rtld-Rules rtld-all \
75	rtld-modules='$(addprefix rtld-,$(rtld-$*))'
76endef
77
78# See subdir-target-args in ../Makefile for the model.
79subdir-args = subdir=$*$(if $($*-srcdir),\
80			    -C $($*-srcdir) ..=`pwd`/,\
81			    -C $(..)$* ..=../)
82
83FORCE:
84
85else
86
87# In this case we are being run by $(rtld-subdir-make), above.
88# Some other subdir's Makefile has provided all its normal rules,
89# and we just provide some additional definitions.
90
91rtld-compile-command.S = $(compile-command.S) $(rtld-CPPFLAGS)
92rtld-compile-command.s = $(compile-command.s) $(rtld-CPPFLAGS)
93rtld-compile-command.c = $(compile-command.c) $(rtld-CPPFLAGS) $(rtld-CFLAGS)
94
95# These are the basic compilation rules corresponding to the Makerules ones.
96# The sysd-rules generated makefile already defines pattern rules for rtld-%
97# targets built from sysdeps source files.
98$(objpfx)rtld-%.os: rtld-%.S $(before-compile)
99	$(rtld-compile-command.S)
100$(objpfx)rtld-%.os: rtld-%.s $(before-compile)
101	$(rtld-compile-command.s)
102$(objpfx)rtld-%.os: rtld-%.c $(before-compile)
103	$(rtld-compile-command.c)
104$(objpfx)rtld-%.os: %.S $(before-compile)
105	$(rtld-compile-command.S)
106$(objpfx)rtld-%.os: %.s $(before-compile)
107	$(rtld-compile-command.s)
108$(objpfx)rtld-%.os: %.c $(before-compile)
109	$(rtld-compile-command.c)
110
111# The rules for generated source files.
112$(objpfx)rtld-%.os: $(objpfx)rtld-%.S $(before-compile)
113	$(rtld-compile-command.S)
114$(objpfx)rtld-%.os: $(objpfx)rtld-%.s $(before-compile)
115	$(rtld-compile-command.s)
116$(objpfx)rtld-%.os: $(objpfx)rtld-%.c $(before-compile)
117	$(rtld-compile-command.c)
118$(objpfx)rtld-%.os: $(objpfx)%.S $(before-compile)
119	$(rtld-compile-command.S)
120$(objpfx)rtld-%.os: $(objpfx)%.s $(before-compile)
121	$(rtld-compile-command.s)
122$(objpfx)rtld-%.os: $(objpfx)%.c $(before-compile)
123	$(rtld-compile-command.c)
124
125# The command line setting of rtld-modules (see above) tells us
126# what we need to build, and that tells us what dependency files we need.
127rtld-all: $(addprefix $(objpfx),$(rtld-modules))
128
129# Figure out the dependency files we need.  After respecting the $(omit-deps)
130# list as applied to the names without the `rtld-', there may be none left.
131rtld-depfiles := $(patsubst %,$(objpfx)rtld-%.os.d,\
132			    $(filter-out $(omit-deps),\
133					 $(rtld-modules:rtld-%.os=%)))
134rtld-depfiles := $(strip $(wildcard $(rtld-depfiles)) \
135			 $(patsubst %.dt,%.d,\
136				    $(wildcard $(rtld-depfiles:.d=.dt))))
137ifdef rtld-depfiles
138-include $(rtld-depfiles)
139endif
140
141# This here is the whole point of all the shenanigans.
142# Set libof-* for each routine.
143cpp-srcs-left := $(rtld-modules:%.os=%)
144lib := rtld
145include $(patsubst %,$(..)libof-iterator.mk,$(cpp-srcs-left))
146
147rtld-CFLAGS += $(no-stack-protector)
148
149endif
150