/* EH stuff Copyright (C) 1997, 1998 Free Software Foundation, Inc. This file is part of GNU CC. This program 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 2, or (at your option) any later version. This program 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. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */ /* This file contains the structures required for the language independant exception handling model. Both the static compiler and the runtime library share this file. */ /* The runtime flag flag_new_exceptions is used to determine whether the compiler supports the new runtime typechecking mechanism or not. Under the new model, runtime info is contained in the exception table, and the __throw() library routine determines which handler to call based on the results of a call to a matching function provided by the expcetion thrower. Otherwise the old scheme of calling any handler which matches an exception range is used, and the handler is responsible for all checking of runtime conditions. If the handler wasn't suppose to get the exception, it performs a re-throw. */ /* The handler_label field MUST be the first field in this structure. The __throw() library routine expects uses __eh_stub() from except.c, which simply dereferences the context pointer to get the handler. The routine get_dynamic_handler_chain() also has a dependancy on the location of 'dynamic_handler_chain'. If its location is changed, that routine must be modified as well. */ struct eh_context { void *handler_label; void **dynamic_handler_chain; /* This is language dependent part of the eh context. */ void *info; /* This is used to remember where we threw for re-throws */ void *table_index; /* address of exception table entry to rethrow from */ }; #ifndef EH_TABLE_LOOKUP typedef struct old_exception_table { void *start_region; void *end_region; void *exception_handler; } old_exception_table; typedef struct exception_table { void *start_region; void *end_region; void *exception_handler; void *match_info; /* runtime type info */ } exception_table; /* The language identifying portion of an exception table */ typedef struct exception_lang_info { short language; short version; } exception_lang_info; /* This value in the first field of the exception descriptor identifies the descriptor as the new model format. This value would never be present in this location under the old model */ #define NEW_EH_RUNTIME ((void *) -2) /* Each function has an exception_descriptor which contains the language info, and a table of exception ranges and handlers */ typedef struct exception_descriptor { void *runtime_id_field; exception_lang_info lang; exception_table table[1]; } exception_descriptor; /* A pointer to a matching function is initialized at runtime by the specific language if run-time exceptions are supported. The function takes 3 parameters 1 - runtime exception that has been thrown info. (__eh_info *) 2 - Match info pointer from the region being considered (void *) 3 - exception table region is in (exception descriptor *) */ typedef void * (*__eh_matcher) PROTO ((void *, void *, void *)); /* This value is to be checked as a 'match all' case in the runtime field. */ #define CATCH_ALL_TYPE ((void *) -1) /* This is the runtime exception information. This forms the minimum required information for an exception info pointer in an eh_context structure. */ typedef struct __eh_info { __eh_matcher match_function; short language; short version; } __eh_info; /* Convienient language codes for ID the originating language. Similar to the codes in dwarf2.h. */ enum exception_source_language { EH_LANG_C89 = 0x0001, EH_LANG_C = 0x0002, EH_LANG_Ada83 = 0x0003, EH_LANG_C_plus_plus = 0x0004, EH_LANG_Cobol74 = 0x0005, EH_LANG_Cobol85 = 0x0006, EH_LANG_Fortran77 = 0x0007, EH_LANG_Fortran90 = 0x0008, EH_LANG_Pascal83 = 0x0009, EH_LANG_Modula2 = 0x000a, EH_LANG_Java = 0x000b, EH_LANG_Mips_Assembler = 0x8001 }; #endif /* EH_TABLE_LOOKUP */