Prepare for radical source tree reorganization. zack/build-layout-experiment

All top-level files and directories are moved into a temporary storage
directory, REORG.TODO, except for files that will certainly still
exist in their current form at top level when we're done (COPYING,
COPYING.LIB, LICENSES, NEWS, README), all old ChangeLog files (which
are moved to the new directory OldChangeLogs, instead), and the
generated file INSTALL (which is just deleted; in the new order, there
will be no generated files checked into version control).

1 files changed, 120 insertions, 0 deletions

diff --git a/REORG.TODO/sysdeps/unix/sysv/linux/i386/makecontext.S b/REORG.TODO/sysdeps/unix/sysv/linux/i386/makecontext.S
new file mode 100644
index 0000000000..6d396dd328
--- /dev/null
+++ b/REORG.TODO/sysdeps/unix/sysv/linux/i386/makecontext.S
@@ -0,0 +1,120 @@
+/* Create new context.
+   Copyright (C) 2001-2017 Free Software Foundation, Inc.
+   This file is part of the GNU C Library.
+   Contributed by Ulrich Drepper <drepper@redhat.com>, 2001.
+
+   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
+   <http://www.gnu.org/licenses/>.  */
+
+#include <sysdep.h>
+
+#include "ucontext_i.h"
+
+
+ENTRY(__makecontext)
+	movl	4(%esp), %eax
+
+	/* Load the address of the function we are supposed to run.  */
+	movl	8(%esp), %ecx
+
+	/* Compute the address of the stack.  The information comes from
+	   to us_stack element.  */
+	movl	oSS_SP(%eax), %edx
+	movl	%ecx, oEIP(%eax)
+	addl	oSS_SIZE(%eax), %edx
+
+	/* Remember the number of parameters for the exit handler since
+	   it has to remove them.  We store the number in the EBX register
+	   which the function we will call must preserve.  */
+	movl	12(%esp), %ecx
+	movl	%ecx, oEBX(%eax)
+
+	/* Make room on the new stack for the parameters.
+	   Room for the arguments, return address (== L(exitcode)) and
+	   oLINK pointer is needed.  One of the pointer sizes is subtracted
+	   after aligning the stack.  */
+	negl	%ecx
+	leal	-4(%edx,%ecx,4), %edx
+	negl	%ecx
+
+	/* Align the stack.  */
+	andl	$0xfffffff0, %edx
+	subl	$4, %edx
+
+	/* Store the future stack pointer.  */
+	movl	%edx, oESP(%eax)
+
+	/* Put the next context on the new stack (from the uc_link
+	   element).  */
+	movl	oLINK(%eax), %eax
+	movl	%eax, 4(%edx,%ecx,4)
+
+	/* Copy all the parameters.  */
+	jecxz	2f
+1:	movl	12(%esp,%ecx,4), %eax
+	movl	%eax, (%edx,%ecx,4)
+	decl	%ecx
+	jnz	1b
+2:
+
+	/* If the function we call returns we must continue with the
+	   context which is given in the uc_link element.  To do this
+	   set the return address for the function the user provides
+	   to a little bit of helper code which does the magic (see
+	   below).  */
+#ifdef PIC
+	call	1f
+	cfi_adjust_cfa_offset (4)
+1:	popl	%ecx
+	cfi_adjust_cfa_offset (-4)
+	addl	$L(exitcode)-1b, %ecx
+	movl	%ecx, (%edx)
+#else
+	movl	$L(exitcode), (%edx)
+#endif
+	/* We need to terminate the FDE here instead of after ret because
+	   the unwinder looks at ra-1 for unwind information.  */
+	cfi_endproc
+
+	/* 'makecontext' returns no value.  */
+	ret
+
+	/* This is the helper code which gets called if a function which
+	   is registered with 'makecontext' returns.  In this case we
+	   have to install the context listed in the uc_link element of
+	   the context 'makecontext' manipulated at the time of the
+	   'makecontext' call.  If the pointer is NULL the process must
+	   terminate.  */
+L(exitcode):
+	/* This removes the parameters passed to the function given to
+	   'makecontext' from the stack.  EBX contains the number of
+	   parameters (see above).  */
+	leal	(%esp,%ebx,4), %esp
+
+	cmpl	$0, (%esp)		/* Check the next context.  */
+	je	2f			/* If it is zero exit.  */
+
+	call	HIDDEN_JUMPTARGET(__setcontext)
+	/* If this returns (which can happen if the syscall fails) we'll
+	   exit the program with the return error value (-1).  */
+
+	movl	%eax, (%esp)
+2:	call	HIDDEN_JUMPTARGET(exit)
+	/* The 'exit' call should never return.  In case it does cause
+	   the process to terminate.  */
+	hlt
+	cfi_startproc
+END(__makecontext)
+
+weak_alias (__makecontext, makecontext)