+++ /dev/null
-// Functions for Exception Support for Java.
-
-/* Copyright (C) 1998, 1999, 2001, 2002 Free Software Foundation
-
- This file is part of libgcj.
-
-This software is copyrighted work licensed under the terms of the
-Libgcj License. Please consult the file "LIBGCJ_LICENSE" for
-details. */
-
-#include <config.h>
-
-#include <stddef.h>
-#include <stdlib.h>
-
-#include <java/lang/Class.h>
-#include <java/lang/NullPointerException.h>
-#include <gcj/cni.h>
-#include <jvm.h>
-
-// unwind-pe.h uses std::abort(), but sometimes we compile libjava
-// without libstdc++-v3. The following hack forces it to use
-// stdlib.h's abort().
-namespace std
-{
- static __attribute__ ((__noreturn__)) void
- abort ()
- {
- ::abort ();
- }
-}
-#include "unwind.h"
-
-struct alignment_test_struct
-{
- char space;
- char end[0] __attribute__((aligned));
-};
-
-struct java_exception_header
-{
- /* Cache handler details between Phase 1 and Phase 2. */
- _Unwind_Ptr landingPad;
- int handlerSwitchValue;
-
- /* The object being thrown. Compiled code expects this to be immediately
- before the generic exception header. Which is complicated by the fact
- that _Unwind_Exception is ((aligned)). */
-
- char pad[sizeof(jthrowable) < sizeof(alignment_test_struct)
- ? sizeof(alignment_test_struct) - sizeof(jthrowable) : 0]
- __attribute__((aligned));
-
- jthrowable value;
-
- /* The generic exception header. */
- _Unwind_Exception unwindHeader;
-};
-
-// This is the exception class we report -- "GNUCJAVA".
-const _Unwind_Exception_Class __gcj_exception_class
-= ((((((((_Unwind_Exception_Class) 'G'
- << 8 | (_Unwind_Exception_Class) 'N')
- << 8 | (_Unwind_Exception_Class) 'U')
- << 8 | (_Unwind_Exception_Class) 'C')
- << 8 | (_Unwind_Exception_Class) 'J')
- << 8 | (_Unwind_Exception_Class) 'A')
- << 8 | (_Unwind_Exception_Class) 'V')
- << 8 | (_Unwind_Exception_Class) 'A');
-
-
-static inline java_exception_header *
-get_exception_header_from_ue (_Unwind_Exception *exc)
-{
- return reinterpret_cast<java_exception_header *>(exc + 1) - 1;
-}
-
-/* Perform a throw, Java style. Throw will unwind through this call,
- so there better not be any handlers or exception thrown here. */
-
-extern "C" void
-_Jv_Throw (jthrowable value)
-{
- java_exception_header *xh
- = static_cast<java_exception_header *>(_Jv_AllocRawObj (sizeof (*xh)));
-
- if (value == NULL)
- value = new java::lang::NullPointerException ();
- xh->value = value;
-
- xh->unwindHeader.exception_class = __gcj_exception_class;
- xh->unwindHeader.exception_cleanup = NULL;
-
- /* We're happy with setjmp/longjmp exceptions or region-based
- exception handlers: entry points are provided here for both. */
- _Unwind_Reason_Code code;
-#ifdef SJLJ_EXCEPTIONS
- code = _Unwind_SjLj_RaiseException (&xh->unwindHeader);
-#else
- code = _Unwind_RaiseException (&xh->unwindHeader);
-#endif
-
- /* If code == _URC_END_OF_STACK, then we reached top of stack without
- finding a handler for the exception. Since each thread is run in
- a try/catch, this oughtn't happen. If code is something else, we
- encountered some sort of heinous lossage from which we could not
- recover. As is the way of such things, almost certainly we will have
- crashed before now, rather than actually being able to diagnose the
- problem. */
- abort();
-}
-
-\f
-#include "unwind-pe.h"
-\f
-struct lsda_header_info
-{
- _Unwind_Ptr Start;
- _Unwind_Ptr LPStart;
- const unsigned char *TType;
- const unsigned char *action_table;
- unsigned char ttype_encoding;
- unsigned char call_site_encoding;
-};
-
-static const unsigned char *
-parse_lsda_header (_Unwind_Context *context, const unsigned char *p,
- lsda_header_info *info)
-{
- _Unwind_Word 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;
-}
-
-static jclass
-get_ttype_entry (_Unwind_Context *context, lsda_header_info *info, long i)
-{
- _Unwind_Ptr ptr;
-
- i *= size_of_encoded_value (info->ttype_encoding);
- read_encoded_value (context, info->ttype_encoding, info->TType - i, &ptr);
-
- return reinterpret_cast<jclass>(ptr);
-}
-
-
-// Using a different personality function name causes link failures
-// when trying to mix code using different exception handling models.
-#ifdef SJLJ_EXCEPTIONS
-#define PERSONALITY_FUNCTION __gcj_personality_sj0
-#define __builtin_eh_return_data_regno(x) x
-#else
-#define PERSONALITY_FUNCTION __gcj_personality_v0
-#endif
-
-extern "C" _Unwind_Reason_Code
-PERSONALITY_FUNCTION (int version,
- _Unwind_Action actions,
- _Unwind_Exception_Class exception_class,
- struct _Unwind_Exception *ue_header,
- struct _Unwind_Context *context)
-{
- java_exception_header *xh = get_exception_header_from_ue (ue_header);
-
- lsda_header_info info;
- const unsigned char *language_specific_data;
- const unsigned char *action_record;
- const unsigned char *p;
- _Unwind_Ptr landing_pad, ip;
- int handler_switch_value;
- bool saw_cleanup;
- bool saw_handler;
-
-
- // Interface version check.
- if (version != 1)
- return _URC_FATAL_PHASE1_ERROR;
-
- // Shortcut for phase 2 found handler for domestic exception.
- if (actions == (_UA_CLEANUP_PHASE | _UA_HANDLER_FRAME)
- && exception_class == __gcj_exception_class)
- {
- handler_switch_value = xh->handlerSwitchValue;
- landing_pad = xh->landingPad;
- goto install_context;
- }
-
- // FIXME: In Phase 1, record _Unwind_GetIP in xh->obj as a part of
- // the stack trace for this exception. This will only collect Java
- // frames, but perhaps that is acceptable.
- // FIXME2: _Unwind_GetIP is nonsensical for SJLJ, being a call-site
- // index instead of a PC value. We could perhaps arrange for
- // _Unwind_GetRegionStart to return context->fc->jbuf[1], which
- // is the address of the handler label for __builtin_longjmp, but
- // there is no solution for DONT_USE_BUILTIN_SETJMP.
-
- language_specific_data = (const unsigned char *)
- _Unwind_GetLanguageSpecificData (context);
-
- // If no LSDA, then there are no handlers or cleanups.
- if (! language_specific_data)
- return _URC_CONTINUE_UNWIND;
-
- // Parse the LSDA header.
- p = parse_lsda_header (context, language_specific_data, &info);
- ip = _Unwind_GetIP (context) - 1;
- landing_pad = 0;
- action_record = 0;
- handler_switch_value = 0;
-
-#ifdef 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
- {
- _Unwind_Word 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 = 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;
- _Unwind_Word 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 // SJLJ_EXCEPTIONS
-
- // If ip is not present in the table, C++ would call terminate.
- // ??? It is perhaps better to tweek the LSDA so that no-action
- // is mapped to no-entry for Java.
- return _URC_CONTINUE_UNWIND;
-
- found_something:
- saw_cleanup = false;
- saw_handler = false;
-
- if (landing_pad == 0)
- {
- // If ip is present, and has a null landing pad, there are
- // no cleanups or handlers to be run.
- }
- else if (action_record == 0)
- {
- // If ip is present, has a non-null landing pad, and a null
- // action table offset, then there are only cleanups present.
- // Cleanups use a zero switch value, as set above.
- saw_cleanup = true;
- }
- else
- {
- // Otherwise we have a catch handler.
- _Unwind_Sword ar_filter, ar_disp;
-
- while (1)
- {
- p = action_record;
- p = read_sleb128 (p, &ar_filter);
- read_sleb128 (p, &ar_disp);
-
- if (ar_filter == 0)
- {
- // Zero filter values are cleanups.
- saw_cleanup = true;
- }
-
- // During forced unwinding, we only run cleanups. With a
- // foreign exception class, we have no class info to match.
- else if ((actions & _UA_FORCE_UNWIND)
- || exception_class != __gcj_exception_class)
- ;
-
- else if (ar_filter > 0)
- {
- // Positive filter values are handlers.
-
- jclass catch_type = get_ttype_entry (context, &info, ar_filter);
-
- // The catch_type is either a (java::lang::Class*) or
- // is one more than a (Utf8Const*).
- if ((size_t)catch_type & 1)
- catch_type = _Jv_FindClass ((Utf8Const*)catch_type - 1, NULL);
-
- if (_Jv_IsInstanceOf (xh->value, catch_type))
- {
- handler_switch_value = ar_filter;
- saw_handler = true;
- break;
- }
- }
- else
- {
- // Negative filter values are exception specifications,
- // which Java does not use.
- // ??? Perhaps better to make them an index into a table
- // of null-terminated strings instead of playing games
- // with Utf8Const+1 as above.
- abort ();
- }
-
- if (ar_disp == 0)
- break;
- action_record = p + ar_disp;
- }
- }
-
- if (! saw_handler && ! saw_cleanup)
- return _URC_CONTINUE_UNWIND;
-
- if (actions & _UA_SEARCH_PHASE)
- {
- if (! saw_handler)
- return _URC_CONTINUE_UNWIND;
-
- // For domestic exceptions, we cache data from phase 1 for phase 2.
- if (exception_class == __gcj_exception_class)
- {
- xh->handlerSwitchValue = handler_switch_value;
- xh->landingPad = landing_pad;
- }
- return _URC_HANDLER_FOUND;
- }
-
- install_context:
- _Unwind_SetGR (context, __builtin_eh_return_data_regno (0),
- (_Unwind_Ptr) &xh->unwindHeader);
- _Unwind_SetGR (context, __builtin_eh_return_data_regno (1),
- handler_switch_value);
- _Unwind_SetIP (context, landing_pad);
- return _URC_INSTALL_CONTEXT;
-}
projects / msp430-gcc.git / blobdiff