Imported gcc-4.4.3

[msp430-gcc.git] / gcc / config / mips / linux-unwind.h

diff --git a/gcc/config/mips/linux-unwind.h b/gcc/config/mips/linux-unwind.h
new file mode 100644 (file)
index 0000000..02f7cd5
--- /dev/null
+++ b/gcc/config/mips/linux-unwind.h
@@ -0,0 +1,120 @@
+/* DWARF2 EH unwinding support for MIPS Linux.
+   Copyright (C) 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.
+
+This file is part of GCC.
+
+GCC 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.
+
+GCC 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.  */
+
+#include <signal.h>
+#include <asm/unistd.h>
+
+/* The third parameter to the signal handler points to something with
+ * this structure defined in asm/ucontext.h, but the name clashes with
+ * struct ucontext from sys/ucontext.h so this private copy is used.  */
+typedef struct _sig_ucontext {
+    unsigned long         uc_flags;
+    struct _sig_ucontext  *uc_link;
+    stack_t               uc_stack;
+    struct sigcontext uc_mcontext;
+    sigset_t      uc_sigmask;
+} _sig_ucontext_t;
+
+#define MD_FALLBACK_FRAME_STATE_FOR mips_fallback_frame_state
+
+static _Unwind_Reason_Code
+mips_fallback_frame_state (struct _Unwind_Context *context,
+                          _Unwind_FrameState *fs)
+{
+  u_int32_t *pc = (u_int32_t *) context->ra;
+  struct sigcontext *sc;
+  _Unwind_Ptr new_cfa, reg_offset;
+  int i;
+
+  /* 24021061 li v0, 0x1061 (rt_sigreturn)*/
+  /* 0000000c syscall    */
+  /*    or */
+  /* 24021017 li v0, 0x1017 (sigreturn) */
+  /* 0000000c syscall  */
+  if (pc[1] != 0x0000000c)
+    return _URC_END_OF_STACK;
+#if _MIPS_SIM == _ABIO32
+  if (pc[0] == (0x24020000 | __NR_sigreturn))
+    {
+      struct sigframe {
+       u_int32_t ass[4];  /* Argument save space for o32.  */
+       u_int32_t trampoline[2];
+       struct sigcontext sigctx;
+      } *rt_ = context->cfa;
+      sc = &rt_->sigctx;
+    }
+  else
+#endif
+  if (pc[0] == (0x24020000 | __NR_rt_sigreturn))
+    {
+      struct rt_sigframe {
+       u_int32_t ass[4];  /* Argument save space for o32.  */
+       u_int32_t trampoline[2];
+       struct siginfo info;
+       _sig_ucontext_t uc;
+      } *rt_ = context->cfa;
+      sc = &rt_->uc.uc_mcontext;
+    }
+  else
+    return _URC_END_OF_STACK;
+
+  new_cfa = (_Unwind_Ptr) sc;
+  fs->regs.cfa_how = CFA_REG_OFFSET;
+  fs->regs.cfa_reg = STACK_POINTER_REGNUM;
+  fs->regs.cfa_offset = new_cfa - (_Unwind_Ptr) context->cfa;
+
+  /* On o32 Linux, the register save slots in the sigcontext are
+     eight bytes.  We need the lower half of each register slot,
+     so slide our view of the structure back four bytes.  */
+#if _MIPS_SIM == _ABIO32 && defined __MIPSEB__
+  reg_offset = 4;
+#else
+  reg_offset = 0;
+#endif
+
+  for (i = 0; i < 32; i++) {
+    fs->regs.reg[i].how = REG_SAVED_OFFSET;
+    fs->regs.reg[i].loc.offset
+      = (_Unwind_Ptr)&(sc->sc_regs[i]) + reg_offset - new_cfa;
+  }
+  /* "PC & -2" points to the faulting instruction, but the unwind code
+     searches for "(ADDR & -2) - 1".  (See MASK_RETURN_ADDR for the source
+     of the -2 mask.)  Adding 2 here ensures that "(ADDR & -2) - 1" is the
+     address of the second byte of the faulting instruction.
+
+     Note that setting fs->signal_frame would not work.  As the comment
+     above MASK_RETURN_ADDR explains, MIPS unwinders must earch for an
+     odd-valued address.  */
+  fs->regs.reg[DWARF_ALT_FRAME_RETURN_COLUMN].how = REG_SAVED_VAL_OFFSET;
+  fs->regs.reg[DWARF_ALT_FRAME_RETURN_COLUMN].loc.offset
+    = (_Unwind_Ptr)(sc->sc_pc) + 2 - new_cfa;
+  fs->retaddr_column = DWARF_ALT_FRAME_RETURN_COLUMN;
+
+  return _URC_NO_REASON;
+}
+#endif