143 lines
4.5 KiB
C
143 lines
4.5 KiB
C
/* EH stuff
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Copyright (C) 1997, 1998 Free Software Foundation, Inc.
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This file is part of GNU CC.
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This program is free software; you can redistribute it and/or modify it
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under the terms of the GNU General Public License as published by the
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Free Software Foundation; either version 2, or (at your option) any
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later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software
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Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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/* This file contains the structures required for the language
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independant exception handling model. Both the static compiler and
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the runtime library share this file. */
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/* The runtime flag flag_new_exceptions is used to determine whether the
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compiler supports the new runtime typechecking mechanism or not. Under
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the new model, runtime info is contained in the exception table, and
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the __throw() library routine determines which handler to call based
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on the results of a call to a matching function provided by the expcetion
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thrower. Otherwise the old scheme of calling any handler which matches
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an exception range is used, and the handler is responsible for all
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checking of runtime conditions. If the handler wasn't suppose to
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get the exception, it performs a re-throw. */
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/* The handler_label field MUST be the first field in this structure. The
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__throw() library routine expects uses __eh_stub() from except.c, which
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simply dereferences the context pointer to get the handler.
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The routine get_dynamic_handler_chain() also has a dependancy on
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the location of 'dynamic_handler_chain'. If its location is changed,
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that routine must be modified as well. */
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struct eh_context
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{
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void *handler_label;
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void **dynamic_handler_chain;
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/* This is language dependent part of the eh context. */
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void *info;
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/* This is used to remember where we threw for re-throws */
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void *table_index; /* address of exception table entry to rethrow from */
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};
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#ifndef EH_TABLE_LOOKUP
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typedef struct old_exception_table
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{
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void *start_region;
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void *end_region;
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void *exception_handler;
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} old_exception_table;
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typedef struct exception_table
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{
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void *start_region;
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void *end_region;
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void *exception_handler;
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void *match_info; /* runtime type info */
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} exception_table;
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/* The language identifying portion of an exception table */
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typedef struct exception_lang_info
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{
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short language;
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short version;
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} exception_lang_info;
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/* This value in the first field of the exception descriptor
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identifies the descriptor as the new model format. This value would never
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be present in this location under the old model */
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#define NEW_EH_RUNTIME ((void *) -2)
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/* Each function has an exception_descriptor which contains the
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language info, and a table of exception ranges and handlers */
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typedef struct exception_descriptor
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{
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void *runtime_id_field;
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exception_lang_info lang;
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exception_table table[1];
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} exception_descriptor;
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/* A pointer to a matching function is initialized at runtime by the
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specific language if run-time exceptions are supported.
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The function takes 3 parameters
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1 - runtime exception that has been thrown info. (__eh_info *)
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2 - Match info pointer from the region being considered (void *)
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3 - exception table region is in (exception descriptor *)
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*/
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typedef void * (*__eh_matcher) PROTO ((void *, void *, void *));
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/* This value is to be checked as a 'match all' case in the runtime field. */
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#define CATCH_ALL_TYPE ((void *) -1)
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/* This is the runtime exception information. This forms the minimum required
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information for an exception info pointer in an eh_context structure. */
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typedef struct __eh_info
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{
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__eh_matcher match_function;
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short language;
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short version;
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} __eh_info;
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/* Convienient language codes for ID the originating language. Similar
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to the codes in dwarf2.h. */
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enum exception_source_language
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{
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EH_LANG_C89 = 0x0001,
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EH_LANG_C = 0x0002,
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EH_LANG_Ada83 = 0x0003,
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EH_LANG_C_plus_plus = 0x0004,
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EH_LANG_Cobol74 = 0x0005,
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EH_LANG_Cobol85 = 0x0006,
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EH_LANG_Fortran77 = 0x0007,
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EH_LANG_Fortran90 = 0x0008,
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EH_LANG_Pascal83 = 0x0009,
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EH_LANG_Modula2 = 0x000a,
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EH_LANG_Java = 0x000b,
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EH_LANG_Mips_Assembler = 0x8001
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};
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#endif /* EH_TABLE_LOOKUP */
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