1# Copyright (C) 1991-2021 Free Software Foundation, Inc.
2# This file is part of the GNU C Library.
3
4# The GNU C Library is free software; you can redistribute it and/or
5# modify it under the terms of the GNU Lesser General Public
6# License as published by the Free Software Foundation; either
7# version 2.1 of the License, or (at your option) any later version.
8
9# The GNU C Library is distributed in the hope that it will be useful,
10# but WITHOUT ANY WARRANTY; without even the implied warranty of
11# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
12# Lesser General Public License for more details.
13
14# You should have received a copy of the GNU Lesser General Public
15# License along with the GNU C Library; if not, see
16# <https://www.gnu.org/licenses/>.
17
18ifndef inhibit-unix-syscalls
19
20# Sysdep dirs unix/... can contain a file syscalls.list,
21# which specifies objects to be compiled as simple Unix system calls.
22
23-include $(common-objpfx)sysd-syscalls
24
25ifeq (misc,$(subdir))
26sysdep_routines += $(unix-extra-syscalls)
27
28ifdef unix-stub-syscalls
29# The system call entry points in this list are supposed to be additional
30# functions not overriding any other sysdeps/.../call.c implementation, but
31# their system call numbers are unavailable in the kernel headers we're
32# using.  Instead of a system call stub, these get a function that fails
33# with ENOSYS.  We just generate a single module defining one function and
34# making all these entry point names aliases for it.
35sysdep_routines += stub-syscalls
36$(objpfx)stub-syscalls.c: $(common-objpfx)sysd-syscalls \
37			  $(..)sysdeps/unix/Makefile
38	$(make-target-directory)
39	(for call in $(unix-stub-syscalls); do \
40	   call=$${call%%@*}; \
41	   echo "#define $$call RENAMED_$$call"; \
42	 done; \
43	 echo '#include <errno.h>'; \
44	 echo '#include <shlib-compat.h>'; \
45	 for call in $(unix-stub-syscalls); do \
46	   call=$${call%%@*}; \
47	   echo "#undef $$call"; \
48	 done; \
49	 echo 'long int _no_syscall (void)'; \
50	 echo '{ __set_errno (ENOSYS); return -1L; }'; \
51	 for call in $(unix-stub-syscalls); do \
52	   case $$call in \
53	   *@@*) \
54	     ver=$${call##*@}; call=$${call%%@*}; \
55	     ver=`echo "$$ver" | sed 's/\./_/g'`; \
56	     echo "strong_alias (_no_syscall, __$${call}_$${ver})"; \
57	     echo "versioned_symbol (libc, __$${call}_$${ver}, $$call, $$ver);"\
58	     ;; \
59	   *@*) \
60	     ver=$${call##*@}; call=$${call%%@*}; \
61	     ver=`echo "$$ver" | sed 's/\./_/g'`; \
62	     case $$ver in \
63	     *:*) \
64	       compat_ver=$${ver#*:}; \
65	       ver=$${ver%%:*}; \
66	       compat_cond="SHLIB_COMPAT (libc, $$ver, $$compat_ver)"; \
67	       ;; \
68	     *) \
69	       compat_cond=""; \
70	       ;; \
71	     esac; \
72	     if [ -n "$$compat_cond" ]; then echo "#if $$compat_cond"; fi; \
73	     echo "strong_alias (_no_syscall, __$${call}_$${ver})"; \
74	     echo "compat_symbol (libc, __$${call}_$${ver}, $$call, $$ver);"; \
75	     if [ -n "$$compat_cond" ]; then echo "#endif"; fi; \
76	     ;; \
77	   *) echo "weak_alias (_no_syscall, $$call)"; \
78	      echo "stub_warning ($$call)"; \
79	      echo "weak_alias (_no_syscall, __GI_$$call)" ;; \
80	   esac; \
81	 done) > $@T
82	mv -f $@T $@
83generated += stub-syscalls.c
84endif
85endif
86
87# This is the end of the pipeline for compiling the syscall stubs.
88# The stdin is assembler with cpp using sysdep.h macros.
89compile-syscall = $(COMPILE.S) -o $@ -x assembler-with-cpp - \
90			       $(compile-mkdep-flags)
91
92ifndef avoid-generated
93$(common-objpfx)sysd-syscalls: $(..)sysdeps/unix/make-syscalls.sh \
94			       $(wildcard $(+sysdep_dirs:%=%/syscalls.list)) \
95			       $(wildcard $(+sysdep_dirs:%=%/arch-syscall.h)) \
96			       $(common-objpfx)libc-modules.stmp
97	for dir in $(+sysdep_dirs); do \
98	  test -f $$dir/syscalls.list && \
99	  { sysdirs='$(sysdirs)' \
100	    asm_CPP='$(COMPILE.S) -E -x assembler-with-cpp' \
101	    $(SHELL) $(dir $<)$(notdir $<) $$dir || exit 1; }; \
102	  test $$dir = $(..)sysdeps/unix && break; \
103	done > $@T
104	mv -f $@T $@
105endif
106
107postclean-generated += sysd-syscalls
108
109endif
110