diff libgcc/unwind-c.c @ 111:04ced10e8804

gcc 7
author kono
date Fri, 27 Oct 2017 22:46:09 +0900
parents
children 84e7813d76e9
line wrap: on
line diff
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/libgcc/unwind-c.c	Fri Oct 27 22:46:09 2017 +0900
@@ -0,0 +1,245 @@
+/* Supporting functions for C exception handling.
+   Copyright (C) 2002-2017 Free Software Foundation, Inc.
+   Contributed by Aldy Hernandez <aldy@quesejoda.com>.
+   Shamelessly stolen from the Java front end.
+
+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/>.  */
+
+#include "tconfig.h"
+#include "tsystem.h"
+#include "auto-target.h"
+#include "unwind.h"
+#define NO_SIZE_OF_ENCODED_VALUE
+#include "unwind-pe.h"
+
+typedef struct
+{
+  _Unwind_Ptr Start;
+  _Unwind_Ptr LPStart;
+  _Unwind_Ptr ttype_base;
+  const unsigned char *TType;
+  const unsigned char *action_table;
+  unsigned char ttype_encoding;
+  unsigned char call_site_encoding;
+} lsda_header_info;
+
+static const unsigned char *
+parse_lsda_header (struct _Unwind_Context *context, const unsigned char *p,
+		   lsda_header_info *info)
+{
+  _uleb128_t tmp;
+  unsigned char lpstart_encoding;
+
+  info->Start = (context ? _Unwind_GetRegionStart (context) : 0);
+
+  /* Find @LPStart, the base to which landing pad offsets are relative.  */
+  lpstart_encoding = *p++;
+  if (lpstart_encoding != DW_EH_PE_omit)
+    p = read_encoded_value (context, lpstart_encoding, p, &info->LPStart);
+  else
+    info->LPStart = info->Start;
+
+  /* Find @TType, the base of the handler and exception spec type data.  */
+  info->ttype_encoding = *p++;
+  if (info->ttype_encoding != DW_EH_PE_omit)
+    {
+      p = read_uleb128 (p, &tmp);
+      info->TType = p + tmp;
+    }
+  else
+    info->TType = 0;
+
+  /* The encoding and length of the call-site table; the action table
+     immediately follows.  */
+  info->call_site_encoding = *p++;
+  p = read_uleb128 (p, &tmp);
+  info->action_table = p + tmp;
+
+  return p;
+}
+
+#ifdef __ARM_EABI_UNWINDER__
+/* ARM EABI personality routines must also unwind the stack.  */
+#define CONTINUE_UNWINDING \
+  do								\
+    {								\
+      if (__gnu_unwind_frame (ue_header, context) != _URC_OK)	\
+	return _URC_FAILURE;					\
+      return _URC_CONTINUE_UNWIND;				\
+    }								\
+  while (0)
+#else
+#define CONTINUE_UNWINDING return _URC_CONTINUE_UNWIND
+#endif
+
+#ifdef __USING_SJLJ_EXCEPTIONS__
+#define PERSONALITY_FUNCTION    __gcc_personality_sj0
+#define __builtin_eh_return_data_regno(x) x
+#elif defined(__SEH__)
+#define PERSONALITY_FUNCTION	__gcc_personality_imp
+#else
+#define PERSONALITY_FUNCTION    __gcc_personality_v0
+#endif
+
+#ifdef __ARM_EABI_UNWINDER__
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (_Unwind_State, struct _Unwind_Exception *,
+		      struct _Unwind_Context *);
+
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (_Unwind_State state,
+		      struct _Unwind_Exception * ue_header,
+		      struct _Unwind_Context * context)
+#else
+#if defined (__SEH__) && !defined (__USING_SJLJ_EXCEPTIONS__)
+static
+#endif
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (int, _Unwind_Action, _Unwind_Exception_Class,
+		      struct _Unwind_Exception *, struct _Unwind_Context *);
+
+_Unwind_Reason_Code
+PERSONALITY_FUNCTION (int version,
+		      _Unwind_Action actions,
+		      _Unwind_Exception_Class exception_class ATTRIBUTE_UNUSED,
+		      struct _Unwind_Exception *ue_header,
+		      struct _Unwind_Context *context)
+#endif
+{
+  lsda_header_info info;
+  const unsigned char *language_specific_data, *p;
+  _Unwind_Ptr landing_pad, ip;
+  int ip_before_insn = 0;
+
+#ifdef __ARM_EABI_UNWINDER__
+  if ((state & _US_ACTION_MASK) != _US_UNWIND_FRAME_STARTING)
+    CONTINUE_UNWINDING;
+
+  /* The dwarf unwinder assumes the context structure holds things like the
+     function and LSDA pointers.  The ARM implementation caches these in
+     the exception header (UCB).  To avoid rewriting everything we make a
+     virtual scratch register point at the UCB.  */
+  ip = (_Unwind_Ptr) ue_header;
+  _Unwind_SetGR (context, UNWIND_POINTER_REG, ip);
+#else
+  if (version != 1)
+    return _URC_FATAL_PHASE1_ERROR;
+
+  /* Currently we only support cleanups for C.  */
+  if ((actions & _UA_CLEANUP_PHASE) == 0)
+    CONTINUE_UNWINDING;
+#endif
+
+  language_specific_data = (const unsigned char *)
+    _Unwind_GetLanguageSpecificData (context);
+
+  /* If no LSDA, then there are no handlers or cleanups.  */
+  if (! language_specific_data)
+    CONTINUE_UNWINDING;
+
+  /* Parse the LSDA header.  */
+  p = parse_lsda_header (context, language_specific_data, &info);
+#ifdef HAVE_GETIPINFO
+  ip = _Unwind_GetIPInfo (context, &ip_before_insn);
+#else
+  ip = _Unwind_GetIP (context);
+#endif
+  if (! ip_before_insn)
+    --ip;
+  landing_pad = 0;
+
+#ifdef __USING_SJLJ_EXCEPTIONS__
+  /* The given "IP" is an index into the call-site table, with two
+     exceptions -- -1 means no-action, and 0 means terminate.  But
+     since we're using uleb128 values, we've not got random access
+     to the array.  */
+  if ((int) ip <= 0)
+    return _URC_CONTINUE_UNWIND;
+  else
+    {
+      _uleb128_t cs_lp, cs_action;
+      do
+	{
+	  p = read_uleb128 (p, &cs_lp);
+	  p = read_uleb128 (p, &cs_action);
+	}
+      while (--ip);
+
+      /* Can never have null landing pad for sjlj -- that would have
+	 been indicated by a -1 call site index.  */
+      landing_pad = (_Unwind_Ptr)cs_lp + 1;
+      goto found_something;
+    }
+#else
+  /* Search the call-site table for the action associated with this IP.  */
+  while (p < info.action_table)
+    {
+      _Unwind_Ptr cs_start, cs_len, cs_lp;
+      _uleb128_t cs_action;
+
+      /* Note that all call-site encodings are "absolute" displacements.  */
+      p = read_encoded_value (0, info.call_site_encoding, p, &cs_start);
+      p = read_encoded_value (0, info.call_site_encoding, p, &cs_len);
+      p = read_encoded_value (0, info.call_site_encoding, p, &cs_lp);
+      p = read_uleb128 (p, &cs_action);
+
+      /* The table is sorted, so if we've passed the ip, stop.  */
+      if (ip < info.Start + cs_start)
+	p = info.action_table;
+      else if (ip < info.Start + cs_start + cs_len)
+	{
+	  if (cs_lp)
+	    landing_pad = info.LPStart + cs_lp;
+	  goto found_something;
+	}
+    }
+#endif
+
+  /* IP is not in table.  No associated cleanups.  */
+  /* ??? This is where C++ calls std::terminate to catch throw
+     from a destructor.  */
+  CONTINUE_UNWINDING;
+
+ found_something:
+  if (landing_pad == 0)
+    {
+      /* IP is present, but has a null landing pad.
+	 No handler to be run.  */
+      CONTINUE_UNWINDING;
+    }
+
+  _Unwind_SetGR (context, __builtin_eh_return_data_regno (0),
+		 (_Unwind_Ptr) ue_header);
+  _Unwind_SetGR (context, __builtin_eh_return_data_regno (1), 0);
+  _Unwind_SetIP (context, landing_pad);
+  return _URC_INSTALL_CONTEXT;
+}
+
+#if defined (__SEH__) && !defined (__USING_SJLJ_EXCEPTIONS__)
+EXCEPTION_DISPOSITION
+__gcc_personality_seh0 (PEXCEPTION_RECORD ms_exc, void *this_frame,
+			PCONTEXT ms_orig_context, PDISPATCHER_CONTEXT ms_disp)
+{
+  return _GCC_specific_handler (ms_exc, this_frame, ms_orig_context,
+				ms_disp, __gcc_personality_imp);
+}
+#endif /* SEH */