generic-morestack.c: Include <string.h>.

libgcc/:
	* generic-morestack.c: Include <string.h>.
	(uintptr_type): Define.
	(struct initial_sp): Add dont_block_signals field.  Reduce size of
	extra array by 1.
	(allocate_segment): Set prev field to NULL.  Don't set
	__morestack_current_segment or __morestack_segments.
	(__generic_morestack): Update current->prev and *pp after calling
	allocate_segment.
	(__morestack_block_signals): Don't do anything if
	dont_block_signals is set.
	(__morestack_unblock_signals): Likewise.
	(__generic_findstack): Check for initial_sp == NULL.  Add casts to
	uintptr_type.
	(__splitstack_block_signals): New function.
	(enum __splitstack_content_offsets): Define.
	(__splitstack_getcontext, __splitstack_setcontext): New functions.
	(__splitstack_makecontext): New function.
	(__splitstack_block_signals_context): New function.
	(__splitstack_find_context): New function.
	* config/i386/morestack.S (__morestack_get_guard): New function.
	(__morestack_set_guard, __morestack_make_guard): New functions.
	* libgcc-std.ver.in: Add new functions to GCC_4.7.0.

gcc/testsuite/:
	* lib/target-supports.exp (check_effective_target_ucontext_h): New
	procedure.
	* gcc.dg/split-5.c: New test.

From-SVN: r181234

gcc/testsuite/ChangeLog

+2011-11-09  Ian Lance Taylor  <iant@google.com>
+
+	* lib/target-supports.exp (check_effective_target_ucontext_h): New
+	procedure.
+	* gcc.dg/split-5.c: New test.
+
 2011-11-09  Patrick Marlier  <patrick.marlier@gmail.com>
 
 	* gcc.dg/tm/memopt-1.c:  Adjust regexp. 

gcc/testsuite/gcc.dg/split-5.c

+/* { dg-do run } */
+/* { dg-require-effective-target split_stack } */
+/* { dg-require-effective-target pthread_h } */
+/* { dg-require-effective-target ucontext_h } */
+/* { dg-options "-pthread -fsplit-stack" } */
+
+#include <stdlib.h>
+#include <pthread.h>
+#include <ucontext.h>
+
+extern void __splitstack_getcontext (void *context[10]);
+
+extern void __splitstack_setcontext (void *context[10]);
+
+extern void *__splitstack_makecontext (size_t, void *context[10], size_t *);
+
+extern void __splitstack_block_signals (int *, int *);
+
+extern void __splitstack_block_signals_context (void *context[10], int *,
+						int *);
+
+extern void *__splitstack_find (void *, void *, size_t *, void **, void **,
+				void **);
+
+extern void *__splitstack_find_context (void *context[10], size_t *, void **,
+					void **, void **);
+
+static ucontext_t c1;
+static void *s1[10];
+
+static ucontext_t c2;
+static void *s2[10];
+
+static void swap (ucontext_t *, void *fs[10], ucontext_t *, void *ts[10])
+  __attribute__ ((no_split_stack));
+
+static void
+swap (ucontext_t *fu, void *fs[10], ucontext_t *tu, void *ts[10])
+{
+  __splitstack_getcontext (fs);
+  __splitstack_setcontext (ts);
+  swapcontext (fu, tu);
+  __splitstack_setcontext (fs);
+}
+
+/* Use a noinline function to ensure that the buffer is not removed
+   from the stack.  */
+static void use_buffer (char *buf) __attribute__ ((noinline));
+static void
+use_buffer (char *buf)
+{
+  buf[0] = '\0';
+}
+
+static void
+down (int i, const char *msg, ucontext_t *me, void *mes[10],
+      ucontext_t *other, void *others[10])
+{
+  char buf[10000];
+
+  if (i > 0)
+    {
+      use_buffer (buf);
+      swap (me, mes, other, others);
+      down (i - 1, msg, me, mes, other, others);
+    }
+  else
+    {
+      int c = 0;
+      void *stack;
+      size_t stack_size;
+      void *next_segment = NULL;
+      void *next_sp = NULL;
+      void *initial_sp = NULL;
+
+      stack = __splitstack_find_context (mes, &stack_size, &next_segment,
+					&next_sp, &initial_sp);
+      if (stack != NULL)
+	{
+	  ++c;
+	  while (__splitstack_find (next_segment, next_sp, &stack_size,
+				    &next_segment, &next_sp, &initial_sp)
+		 != NULL)
+	    ++c;
+	}
+    }
+}
+
+static void
+go1 (void)
+{
+  down (1000, "go1", &c1, s1, &c2, s2);
+  pthread_exit (NULL);
+}
+
+static void
+go2 (void)
+{
+  down (1000, "go2", &c2, s2, &c1, s1);
+  pthread_exit (NULL);
+}
+
+struct thread_context
+{
+  ucontext_t *u;
+  void **s;
+};
+
+static void *start_thread (void *) __attribute__ ((no_split_stack));
+
+static void *
+start_thread (void *context)
+{
+  struct thread_context *tc = (struct thread_context *) context;
+  int block;
+
+  block = 0;
+  __splitstack_block_signals (&block, NULL);
+  __splitstack_setcontext (tc->s);
+  setcontext (tc->u);
+  abort ();
+}
+
+int
+main (int argc __attribute__ ((unused)), char **argv __attribute__ ((unused)))
+{
+  pthread_t tid;
+  int err;
+  size_t size;
+  struct thread_context tc;
+  int block;
+
+  if (getcontext (&c1) < 0)
+    abort ();
+
+  c2 = c1;
+
+  c1.uc_stack.ss_sp = __splitstack_makecontext (8192, &s1[0], &size);
+  if (c1.uc_stack.ss_sp == NULL)
+    abort ();
+  c1.uc_stack.ss_flags = 0;
+  c1.uc_stack.ss_size = size;
+  c1.uc_link = NULL;
+  block = 0;
+  __splitstack_block_signals_context (&s1[0], &block, NULL);
+  makecontext (&c1, go1, 0);
+
+  c2.uc_stack.ss_sp = __splitstack_makecontext (8192, &s2[0], &size);
+  if (c2.uc_stack.ss_sp == NULL)
+    abort ();
+  c2.uc_stack.ss_flags = 0;
+  c2.uc_stack.ss_size = size;
+  c2.uc_link = NULL;
+  __splitstack_block_signals_context (&s2[0], &block, NULL);
+  makecontext (&c2, go2, 0);
+
+  block = 0;
+  __splitstack_block_signals (&block, NULL);
+
+  tc.u = &c1;
+  tc.s = &s1[0];
+  err = pthread_create (&tid, NULL, start_thread, &tc);
+  if (err != 0)
+    abort ();
+
+  err = pthread_join (tid, NULL);
+  if (err != 0)
+    abort ();
+
+  return 0;
+}

gcc/testsuite/lib/target-supports.exp

@@ -4401,3 +4401,11 @@ proc check_effective_target_non_strict_align {} {
 	void foo(void) { z = (c *) y; }
     } "-Wcast-align"]
 }
+
+# Return 1 if the target has <ucontext.h>.
+
+proc check_effective_target_ucontext_h { } {
+    return [check_no_compiler_messages ucontext_h assembly {
+	#include <ucontext.h>
+    }]
+}

libgcc/ChangeLog

+2011-11-09  Ian Lance Taylor  <iant@google.com>
+
+	* generic-morestack.c: Include <string.h>.
+	(uintptr_type): Define.
+	(struct initial_sp): Add dont_block_signals field.  Reduce size of
+	extra array by 1.
+	(allocate_segment): Set prev field to NULL.  Don't set
+	__morestack_current_segment or __morestack_segments.
+	(__generic_morestack): Update current->prev and *pp after calling
+	allocate_segment.
+	(__morestack_block_signals): Don't do anything if
+	dont_block_signals is set.
+	(__morestack_unblock_signals): Likewise.
+	(__generic_findstack): Check for initial_sp == NULL.  Add casts to
+	uintptr_type.
+	(__splitstack_block_signals): New function.
+	(enum __splitstack_content_offsets): Define.
+	(__splitstack_getcontext, __splitstack_setcontext): New functions.
+	(__splitstack_makecontext): New function.
+	(__splitstack_block_signals_context): New function.
+	(__splitstack_find_context): New function.
+	* config/i386/morestack.S (__morestack_get_guard): New function.
+	(__morestack_set_guard, __morestack_make_guard): New functions.
+	* libgcc-std.ver.in: Add new functions to GCC_4.7.0.
+
 2011-11-09  Rainer Orth  <ro@CeBiTec.Uni-Bielefeld.DE>
 
 	* config.host (i[34567]86-*-cygwin*): Move i386/t-mingw-pthread ...

libgcc/config/i386/morestack.S

 # x86/x86_64 support for -fsplit-stack.
-# Copyright (C) 2009, 2010 Free Software Foundation, Inc.
+# Copyright (C) 2009, 2010, 2011 Free Software Foundation, Inc.
 # Contributed by Ian Lance Taylor <iant@google.com>.
 
 # This file is part of GCC.
@@ -620,6 +620,82 @@ __stack_split_initialize:
 	.size	__stack_split_initialize, . - __stack_split_initialize
 #endif
 
+# Routines to get and set the guard, for __splitstack_getcontext,
+# __splitstack_setcontext, and __splitstack_makecontext.
+
+# void *__morestack_get_guard (void) returns the current stack guard.
+	.text
+	.global	__morestack_get_guard
+	.hidden	__morestack_get_guard
+
+#ifdef __ELF__
+	.type	__morestack_get_guard,@function
+#endif
+
+__morestack_get_guard:
+
+#ifndef __x86_64__
+	movl	%gs:0x30,%eax
+#else
+#ifdef __LP64__
+	movq	%fs:0x70,%rax
+#else
+	movl	%fs:0x40,%eax
+#endif
+#endif
+	ret
+
+#ifdef __ELF__
+	.size	__morestack_get_guard, . - __morestack_get_guard
+#endif
+
+# void __morestack_set_guard (void *) sets the stack guard.
+	.global	__morestack_set_guard
+	.hidden	__morestack_set_guard
+
+#ifdef __ELF__
+	.type	__morestack_set_guard,@function
+#endif
+
+__morestack_set_guard:
+
+#ifndef __x86_64__
+	movl	4(%esp),%eax
+	movl	%eax,%gs:0x30
+#else
+	X86_64_SAVE_NEW_STACK_BOUNDARY (di)
+#endif
+	ret
+
+#ifdef __ELF__
+	.size	__morestack_set_guard, . - __morestack_set_guard
+#endif
+
+# void *__morestack_make_guard (void *, size_t) returns the stack
+# guard value for a stack.
+	.global	__morestack_make_guard
+	.hidden	__morestack_make_guard
+
+#ifdef __ELF__
+	.type	__morestack_make_guard,@function
+#endif
+
+__morestack_make_guard:
+
+#ifndef __x86_64__
+	movl	4(%esp),%eax
+	subl	8(%esp),%eax
+	addl	$BACKOFF,%eax
+#else
+	subq	%rsi,%rdi
+	addq	$BACKOFF,%rdi
+	movq	%rdi,%rax
+#endif
+	ret
+
+#ifdef __ELF__
+	.size	__morestack_make_guard, . - __morestack_make_guard
+#endif
 
 # Make __stack_split_initialize a high priority constructor.  FIXME:
 # This is ELF specific.

libgcc/libgcc-std.ver.in

 # Copyright (C) 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007,
-# 2008, 2010 Free Software Foundation, Inc.
+# 2008, 2010, 2011 Free Software Foundation, Inc.
 #
 # This file is part of GCC.
 #
@@ -1926,4 +1926,10 @@ GCC_4.7.0 {
   __PFX__clrsbsi2
   __PFX__clrsbdi2
   __PFX__clrsbti2
+  __splitstack_block_signals
+  __splitstack_getcontext
+  __splitstack_setcontext
+  __splitstack_makecontext
+  __splitstack_block_signals_context
+  __splitstack_find_context
 }