--- /dev/null
+/* Supporting functions for C exception handling.
+ Copyright (C) 2002, 2003, 2009 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 "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
+#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
+_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, *action_record;
+ _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 the
+ virtual IP register point at the UCB. */
+ ip = (_Unwind_Ptr) ue_header;
+ _Unwind_SetGR (context, 12, 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;
+ if (cs_action)
+ action_record = info.action_table + cs_action - 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;
+ if (cs_action)
+ action_record = info.action_table + cs_action - 1;
+ 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;
+}
projects / msp430-gcc.git / blobdiff