sysdeps/unix/Makefile

   1 # Copyright (C) 1991-2024 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
  18 ifndef 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 $(common-objpfx)sysd-syscalls
  24
  25 ifeq (misc,$(subdir))
  26 sysdep_routines += $(unix-extra-syscalls)
  27
  28 ifdef 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.
  35 sysdep_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_$$call)" ;; \
  80            esac; \
  81          done) > $@T
  82         mv -f $@T $@
  83 generated += stub-syscalls.c
  84 endif
  85 endif
  86
  87 # This is the end of the pipeline for compiling the syscall stubs.
  88 # The stdin is assembler with cpp using sysdep.h macros.
  89 compile-syscall = $(COMPILE.S) -o $@ -x assembler-with-cpp - \
  90                                $(compile-mkdep-flags)
  91
  92 ifndef avoid-generated
  93 $(common-objpfx)sysd-syscalls: $(..)sysdeps/unix/make-syscalls.sh \
  94                                $(wildcard $(+sysdep_dirs:%=%/syscalls.list)) \
  95                                $(wildcard $(+sysdep_dirs:%=%/arch-syscall.h)) \
  96                                $(common-objpfx)libc-modules.stmp
  97         for dir in $(+sysdep_dirs); do \
  98           test -f $$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 $@
 105 endif
 106
 107 postclean-generated += sysd-syscalls
 108
 109 endif