Imported gcc-4.4.3

[msp430-gcc.git] / gcc / config / s390 / linux-unwind.h

diff --git a/gcc/config/s390/linux-unwind.h b/gcc/config/s390/linux-unwind.h
new file mode 100644 (file)
index 0000000..558087f
--- /dev/null
+++ b/gcc/config/s390/linux-unwind.h
@@ -0,0 +1,130 @@
+/* DWARF2 EH unwinding support for S/390 Linux.
+   Copyright (C) 2004, 2005, 2006, 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/>.  */
+
+/* Do code reading to identify a signal frame, and set the frame
+   state data appropriately.  See unwind-dw2.c for the structs.  */
+
+#define MD_FALLBACK_FRAME_STATE_FOR s390_fallback_frame_state
+
+static _Unwind_Reason_Code
+s390_fallback_frame_state (struct _Unwind_Context *context,
+                          _Unwind_FrameState *fs)
+{
+  unsigned char *pc = context->ra;
+  long new_cfa;
+  int i;
+
+  typedef struct
+  {
+    unsigned long psw_mask;
+    unsigned long psw_addr;
+    unsigned long gprs[16];
+    unsigned int  acrs[16];
+    unsigned int  fpc;
+    unsigned int  __pad;
+    double        fprs[16];
+  } __attribute__ ((__aligned__ (8))) sigregs_;
+
+  sigregs_ *regs;
+  int *signo;
+
+  /* svc $__NR_sigreturn or svc $__NR_rt_sigreturn  */
+  if (pc[0] != 0x0a || (pc[1] != 119 && pc[1] != 173))
+    return _URC_END_OF_STACK;
+
+  /* Legacy frames:
+       old signal mask (8 bytes)
+       pointer to sigregs (8 bytes) - points always to next location
+       sigregs
+       retcode
+     This frame layout was used on kernels < 2.6.9 for non-RT frames,
+     and on kernels < 2.4.13 for RT frames as well.  Note that we need
+     to look at RA to detect this layout -- this means that if you use
+     sa_restorer to install a different signal restorer on a legacy
+     kernel, unwinding from signal frames will not work.  */
+  if (context->ra == context->cfa + 16 + sizeof (sigregs_))
+    {
+      regs = (sigregs_ *)(context->cfa + 16);
+      signo = NULL;
+    }
+
+  /* New-style RT frame:
+     retcode + alignment (8 bytes)
+     siginfo (128 bytes)
+     ucontext (contains sigregs)  */
+  else if (pc[1] == 173 /* __NR_rt_sigreturn */)
+    {
+      struct ucontext_
+      {
+       unsigned long     uc_flags;
+       struct ucontext_ *uc_link;
+       unsigned long     uc_stack[3];
+       sigregs_          uc_mcontext;
+      } *uc = context->cfa + 8 + 128;
+
+      regs = &uc->uc_mcontext;
+      signo = context->cfa + sizeof(long);
+    }
+
+  /* New-style non-RT frame:
+     old signal mask (8 bytes)
+     pointer to sigregs (followed by signal number)  */
+  else
+    {
+      regs = *(sigregs_ **)(context->cfa + 8);
+      signo = (int *)(regs + 1);
+    }
+
+  new_cfa = regs->gprs[15] + 16*sizeof(long) + 32;
+  fs->regs.cfa_how = CFA_REG_OFFSET;
+  fs->regs.cfa_reg = 15;
+  fs->regs.cfa_offset =
+    new_cfa - (long) context->cfa + 16*sizeof(long) + 32;
+
+  for (i = 0; i < 16; i++)
+    {
+      fs->regs.reg[i].how = REG_SAVED_OFFSET;
+      fs->regs.reg[i].loc.offset =
+       (long)&regs->gprs[i] - new_cfa;
+    }
+  for (i = 0; i < 16; i++)
+    {
+      fs->regs.reg[16+i].how = REG_SAVED_OFFSET;
+      fs->regs.reg[16+i].loc.offset =
+       (long)&regs->fprs[i] - new_cfa;
+    }
+
+  /* Load return addr from PSW into dummy register 32.  */
+
+  fs->regs.reg[32].how = REG_SAVED_OFFSET;
+  fs->regs.reg[32].loc.offset = (long)&regs->psw_addr - new_cfa;
+  fs->retaddr_column = 32;
+  /* SIGILL, SIGFPE and SIGTRAP are delivered with psw_addr
+     after the faulting instruction rather than before it.
+     Don't set FS->signal_frame in that case.  */
+  if (!signo || (*signo != 4 && *signo != 5 && *signo != 8))
+    fs->signal_frame = 1;
+
+  return _URC_NO_REASON;
+}