Initial checkin of GCC 4.9.0 from trunk (r208799).

Change-Id: I48a3c08bb98542aa215912a75f03c0890e497dba

1 files changed, 106 insertions, 0 deletions

diff --git a/gcc-4.9/libgcc/config/nios2/linux-unwind.h b/gcc-4.9/libgcc/config/nios2/linux-unwind.h
new file mode 100644
index 000000000..92ff1f629
--- /dev/null
+++ b/gcc-4.9/libgcc/config/nios2/linux-unwind.h
@@ -0,0 +1,106 @@
+/* DWARF2 EH unwinding support for Nios II Linux.
+   Copyright (C) 2008-2014 Free Software Foundation, Inc.
+
+This file is free software; you can redistribute it and/or modify it
+under the terms of the GNU General Public License as published by the
+Free Software Foundation; either version 3, or (at your option) any
+later version.
+
+This file 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
+General Public License for more details.
+
+Under Section 7 of GPL version 3, you are granted additional
+permissions described in the GCC Runtime Library Exception, version
+3.1, as published by the Free Software Foundation.
+
+You should have received a copy of the GNU General Public License and
+a copy of the GCC Runtime Library Exception along with this program;
+see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
+<http://www.gnu.org/licenses/>.  */
+
+#ifndef inhibit_libc
+
+/* Do code reading to identify a signal frame, and set the frame
+   state data appropriately.  See unwind-dw2.c for the structs.
+   The corresponding bits in the Linux kernel are in
+   arch/nios2/kernel/signal.c.  */
+
+#include <signal.h>
+#include <asm/unistd.h>
+
+/* Exactly the same layout as the kernel structures, unique names.  */
+struct nios2_mcontext {
+  int version;
+  int gregs[32];
+};
+
+struct nios2_ucontext {
+  unsigned long uc_flags;
+  struct ucontext *uc_link;
+  stack_t uc_stack;
+  struct nios2_mcontext uc_mcontext;
+  sigset_t uc_sigmask;	/* mask last for extensibility */
+};
+
+#define MD_FALLBACK_FRAME_STATE_FOR nios2_fallback_frame_state
+
+static _Unwind_Reason_Code
+nios2_fallback_frame_state (struct _Unwind_Context *context,
+			    _Unwind_FrameState *fs)
+{
+  u_int32_t *pc = (u_int32_t *) context->ra;
+  _Unwind_Ptr new_cfa;
+
+  /* The expected sequence of instructions is:
+       movi r2,(rt_sigreturn)
+       trap
+     Check for the trap first.  */
+  if (pc[1] != 0x003b683a)
+    return _URC_END_OF_STACK;
+
+#define NIOS2_REG(NUM,NAME)						\
+  (fs->regs.reg[NUM].how = REG_SAVED_OFFSET,				\
+   fs->regs.reg[NUM].loc.offset = (_Unwind_Ptr)&(regs->NAME) - new_cfa)
+
+  if (pc[0] == (0x00800004 | (__NR_rt_sigreturn << 6)))
+    {
+      struct rt_sigframe {
+	char retcode[12];
+	siginfo_t info;
+	struct nios2_ucontext uc;
+      } *rt_ = context->ra;
+      struct nios2_mcontext *regs = &rt_->uc.uc_mcontext;
+      int i;
+
+      /* MCONTEXT_VERSION is defined to 2 in the kernel.  */
+      if (regs->version != 2)
+	return _URC_END_OF_STACK;
+
+      /* The CFA is the user's incoming stack pointer value.  */
+      new_cfa = (_Unwind_Ptr)regs->gregs[28];
+      fs->regs.cfa_how = CFA_REG_OFFSET;
+      fs->regs.cfa_reg = STACK_POINTER_REGNUM;
+      fs->regs.cfa_offset = new_cfa - (_Unwind_Ptr) context->cfa;
+
+      /* The sequential registers.  */
+      for (i = 1; i < 24; i++)
+	NIOS2_REG (i, gregs[i-1]);
+      
+      /* The random registers.  The kernel stores these in a funny order
+	 in the gregs array.  */
+      NIOS2_REG (RA_REGNO, gregs[23]);
+      NIOS2_REG (FP_REGNO, gregs[24]);
+      NIOS2_REG (GP_REGNO, gregs[25]);
+      NIOS2_REG (EA_REGNO, gregs[27]);
+      
+      fs->retaddr_column = EA_REGNO;
+      fs->signal_frame = 1;
+      
+      return _URC_NO_REASON;
+    }
+#undef NIOS2_REG
+  return _URC_END_OF_STACK;
+}
+#endif