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authorRoland McGrath <roland@redhat.com>2009-08-23 17:43:21 -0700
committerRoland McGrath <roland@redhat.com>2009-08-24 11:40:15 -0700
commit036e46b655557f9a17784e502f694a80abfd68dc (patch)
tree13d443cd242f9e7a26465894b8d0d24442cfd0e1
parent7b943af6cf2bfd4b94be271877a10128c32d03da (diff)
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Add sysdeps/unix/syscall-template.S; build syscall stubs with deps and -g pointing to it.
-rw-r--r--ChangeLog9
-rw-r--r--sysdeps/unix/Makefile18
-rw-r--r--sysdeps/unix/make-syscalls.sh33
-rw-r--r--sysdeps/unix/syscall-template.S88
4 files changed, 124 insertions, 24 deletions
diff --git a/ChangeLog b/ChangeLog
index b367ab0782..15171569ea 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2009-08-24 Roland McGrath <roland@redhat.com>
+
+ * sysdeps/unix/syscall-template.S: New file.
+ * sysdeps/unix/make-syscalls.sh: Generate rules to use it.
+ * sysdeps/unix/Makefile (omit-deps): Do not omit syscall stubs' deps.
+ (compile-syscall): Pass mkdep and -g options as normal.
+ (s-proto.d, s-proto-cancel.d): Don't "-include" these.
+ (common-generated): Don't add them here.
+
2009-08-24 Ulrich Drepper <drepper@redhat.com>
* math/math.h: Define math_errhandling of __FAST_MATH__ is not defined.
diff --git a/sysdeps/unix/Makefile b/sysdeps/unix/Makefile
index 2696e7fb62..f7140884a1 100644
--- a/sysdeps/unix/Makefile
+++ b/sysdeps/unix/Makefile
@@ -1,4 +1,4 @@
-# Copyright (C) 1991,1992,1993,1994,1995,1996,1997,1998,1999,2003, 2006, 2008
+# Copyright (C) 1991,1992,1993,1994,1995,1996,1997,1998,1999,2003,2006,2008,2009
# Free Software Foundation, Inc.
# This file is part of the GNU C Library.
@@ -260,7 +260,6 @@ ifndef inhibit-unix-syscalls
# which specifies objects to be compiled as simple Unix system calls.
-include $(common-objpfx)sysd-syscalls
-omit-deps += $(foreach t,$(sysd-rules-targets),$(unix-syscalls:%=$t))
ifeq (misc,$(subdir))
sysdep_routines += $(unix-extra-syscalls)
@@ -306,9 +305,9 @@ endif
endif
# This is the end of the pipeline for compiling the syscall stubs.
-# The stdin in assembler with cpp using sysdep.h macros.
-# Be sure to disable debugging info since it would all just say "<stdin>".
-compile-syscall = $(filter-out -g%,$(COMPILE.S)) -x assembler-with-cpp -o $@ -
+# The stdin is assembler with cpp using sysdep.h macros.
+compile-syscall = $(COMPILE.S) -o $@ -x assembler-with-cpp - \
+ $(compile-mkdep-flags)
ifndef avoid-generated
$(common-objpfx)sysd-syscalls: $(..)sysdeps/unix/make-syscalls.sh \
@@ -323,16 +322,13 @@ $(common-objpfx)sysd-syscalls: $(..)sysdeps/unix/make-syscalls.sh \
mv -f $@T $@
endif
-# The syscall objects depend on s-proto.d or s-proto-cancel.d, which
-# are generated to specify dependencies generated syscalls have on
-# headers.
+# The $(bppfx)syscall.ob objects depend on s-proto-bp.d, which are
+# generated to specify dependencies generated BP stubs have on headers.
# These deps use file names relative to a subdir, so don't
# include them in the parent directory.
ifneq (,$(filter $(unix-syscalls),$(routines) $(sysdep_routines) $(aux)))
ifndef no_deps
--include $(common-objpfx)s-proto.d
-include $(common-objpfx)s-proto-bp.d
--include $(common-objpfx)s-proto-cancel.d
endif
endif
@@ -340,7 +336,7 @@ $(common-objpfx)s-%.d: $(..)sysdeps/unix/s-%.S \
$(wildcard $(+sysdep_dirs:%=%/syscalls.list))
$(+make-deps)
-common-generated += s-proto.d s-proto-bp.d s-proto-cancel.d
+common-generated += s-proto-bp.d
postclean-generated += sysd-syscalls
endif
diff --git a/sysdeps/unix/make-syscalls.sh b/sysdeps/unix/make-syscalls.sh
index 8abb0349bf..a8b8a262a7 100644
--- a/sysdeps/unix/make-syscalls.sh
+++ b/sysdeps/unix/make-syscalls.sh
@@ -83,12 +83,13 @@ while read file srcfile caller syscall args strong weak; do
;;
esac
- cancellable=
- noerrno=
+ cancellable=0
+ noerrno=0
+ errval=0
case $args in
- C*) cancellable=-cancel; args=`echo $args | sed 's/C:\?//'`;;
- E*) noerrno=_NOERRNO; args=`echo $args | sed 's/E:\?//'`;;
- V*) noerrno=_ERRVAL; args=`echo $args | sed 's/V:\?//'`;;
+ C*) cancellable=1; args=`echo $args | sed 's/C:\?//'`;;
+ E*) noerrno=1; args=`echo $args | sed 's/E:\?//'`;;
+ V*) errval=1; args=`echo $args | sed 's/V:\?//'`;;
esac
# Derive the number of arguments from the argument signature
@@ -115,7 +116,7 @@ while read file srcfile caller syscall args strong weak; do
x--)
# Undefined callnum for an extra syscall.
if [ x$caller != x- ]; then
- if [ x$noerrno != x ]; then
+ if [ $noerrno != 0 ]; then
echo >&2 "$0: no number for $fileno, no-error syscall ($strong $weak)"
exit 2
fi
@@ -151,7 +152,7 @@ shared-only-routines += $file
;;
esac
- echo " \$(common-objpfx)s-proto$cancellable.d"
+ echo " \$(..)sysdeps/unix/make-syscalls.sh"
case x"$callnum" in
x_)
echo "\
@@ -161,11 +162,17 @@ shared-only-routines += $file
x*)
echo "\
\$(make-target-directory)
- (echo '#include <sysdep$cancellable.h>'; \\
- echo 'PSEUDO$noerrno ($strong, $syscall, $nargs)'; \\
- echo ' ret$noerrno'; \\
- echo 'PSEUDO_END$noerrno($strong)'; \\
- echo 'libc_hidden_def ($strong)'; \\"
+ (echo '#define SYSCALL_NAME $syscall'; \\
+ echo '#define SYSCALL_NARGS $nargs'; \\
+ echo '#define SYSCALL_SYMBOL $strong'; \\"
+ [ $cancellable = 0 ] || echo "\
+ echo '#define SYSCALL_CANCELLABLE 1'; \\"
+ [ $noerrno = 0 ] || echo "\
+ echo '#define SYSCALL_NOERRNO 1'; \\"
+ [ $errval = 0 ] || echo "\
+ echo '#define SYSCALL_ERRVAL 1'; \\"
+ echo "\
+ echo '#include <syscall-template.S>'; \\"
;;
esac
@@ -201,7 +208,7 @@ shared-only-routines += $file
vcount=`expr $vcount + 1`
echo " echo 'strong_alias ($strong, $source)'; \\"
fi
- echo " echo 'symbol_version($source, $base, $ver)'; \\"
+ echo " echo 'symbol_version ($source, $base, $ver)'; \\"
;;
!*)
name=`echo $name | sed 's/.//'`
diff --git a/sysdeps/unix/syscall-template.S b/sysdeps/unix/syscall-template.S
new file mode 100644
index 0000000000..66319f158b
--- /dev/null
+++ b/sysdeps/unix/syscall-template.S
@@ -0,0 +1,88 @@
+/* Assembly code template for system call stubs.
+ Copyright (C) 2009 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, write to the Free
+ Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA
+ 02111-1307 USA. */
+
+/* The real guts of this work are in the macros defined in the
+ machine- and kernel-specific sysdep.h header file. When we
+ are defining a cancellable system call, the sysdep-cancel.h
+ versions of those macros are what we really use.
+
+ Each system call's object is built by a rule in sysd-syscalls
+ generated by make-syscalls.sh that #include's this file after
+ defining a few macros:
+ SYSCALL_NAME syscall name
+ SYSCALL_NARGS number of arguments this call takes
+ SYSCALL_SYMBOL primary symbol name
+ SYSCALL_CANCELLABLE 1 if the call is a cancelation point
+ SYSCALL_NOERRNO 1 to define a no-errno version (see below)
+ SYSCALL_ERRVAL 1 to define an error-value version (see below)
+
+ We used to simply pipe the correct three lines below through cpp into
+ the assembler. The main reason to have this file instead is so that
+ stub objects can be assembled with -g and get source line information
+ that leads a user back to a source file and these fine comments. The
+ average user otherwise has a hard time knowing which "syscall-like"
+ functions in libc are plain stubs and which have nontrivial C wrappers.
+ Some versions of the "plain" stub generation macros are more than a few
+ instructions long and the untrained eye might not distinguish them from
+ some compiled code that inexplicably lacks source line information. */
+
+#if SYSCALL_CANCELLABLE
+# include <sysdep-cancel.h>
+#else
+# include <sysdep.h>
+#endif
+
+#define T_PSEUDO(SYMBOL, NAME, N) PSEUDO (SYMBOL, NAME, N)
+#define T_PSEUDO_NOERRNO(SYMBOL, NAME, N) PSEUDO_NOERRNO (SYMBOL, NAME, N)
+#define T_PSEUDO_ERRVAL(SYMBOL, NAME, N) PSEUDO_ERRVAL (SYMBOL, NAME, N)
+#define T_PSEUDO_END(SYMBOL) PSEUDO_END (SYMBOL)
+#define T_PSEUDO_END_NOERRNO(SYMBOL) PSEUDO_END_NOERRNO (SYMBOL)
+#define T_PSEUDO_END_ERRVAL(SYMBOL) PSEUDO_END_ERRVAL (SYMBOL)
+
+#if SYSCALL_NOERRNO
+
+/* This kind of system call stub never returns an error.
+ We return the return value register to the caller unexamined. */
+
+T_PSEUDO_NOERRNO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
+ ret_NOERRNO
+T_PSEUDO_END_NOERRNO (SYSCALL_SYMBOL)
+
+#elif SYSCALL_ERRVAL
+
+/* This kind of system call stub returns the errno code as its return
+ value, or zero for success. We may massage the kernel's return value
+ to meet that ABI, but we never set errno here. */
+
+T_PSEUDO_ERRVAL (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
+ ret_ERRVAL
+T_PSEUDO_END_ERRVAL (SYSCALL_SYMBOL)
+
+#else
+
+/* This is a "normal" system call stub: if there is an error,
+ it returns -1 and sets errno. */
+
+T_PSEUDO (SYSCALL_SYMBOL, SYSCALL_NAME, SYSCALL_NARGS)
+ ret
+T_PSEUDO_END (SYSCALL_SYMBOL)
+
+#endif
+
+libc_hidden_def (SYSCALL_SYMBOL)