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/* Copyright (C) 1997 Free Software Foundation, Inc.
This file is part of GNU CC. */
/* 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. */
#include "gansidecl.h"
/* 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;
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 */