1 /* Copyright (C) 1997 Free Software Foundation, Inc.
2 This file is part of GNU CC. */
4 /* This file contains the structures required for the language
5 independant exception handling model. Both the static compiler and
6 the runtime library share this file. */
8 /* The runtime flag flag_new_exceptions is used to determine whether the
9 compiler supports the new runtime typechecking mechanism or not. Under
10 the new model, runtime info is contained in the exception table, and
11 the __throw() library routine determines which handler to call based
12 on the results of a call to a matching function provided by the expcetion
13 thrower. Otherwise the old scheme of calling any handler which matches
14 an exception range is used, and the handler is responsible for all
15 checking of runtime conditions. If the handler wasn't suppose to
16 get the exception, it performs a re-throw. */
19 /* The handler_label field MUST be the first field in this structure. The
20 __throw() library routine expects uses __eh_stub() from except.c, which
21 simply dereferences the context pointer to get the handler.
22 The routine get_dynamic_handler_chain() also has a dependancy on
23 the location of 'dynamic_handler_chain'. If its location is changed,
24 that routine must be modified as well. */
29 void **dynamic_handler_chain;
30 /* This is language dependent part of the eh context. */
34 #ifndef EH_TABLE_LOOKUP
36 typedef struct old_exception_table
40 void *exception_handler;
41 } old_exception_table;
43 typedef struct exception_table
47 void *exception_handler;
48 void *match_info; /* runtime type info */
52 /* The language identifying portion of an exception table */
54 typedef struct exception_lang_info
58 } exception_lang_info;
60 /* This value in the first field of the exception descriptor
61 identifies the descriptor as the new model format. This value would never
62 be present in this location under the old model */
64 #define NEW_EH_RUNTIME ((void *) -2)
66 /* Each function has an exception_descriptor which contains the
67 language info, and a table of exception ranges and handlers */
69 typedef struct exception_descriptor
71 void *runtime_id_field;
72 exception_lang_info lang;
73 exception_table table[1];
74 } exception_descriptor;
77 /* A pointer to a matching function is initialized at runtime by the
78 specific language if run-time exceptions are supported.
79 The function takes 3 parameters
80 1 - runtime exception that has been thrown info. (__eh_info *)
81 2 - Match info pointer from the region being considered (void *)
82 3 - exception table region is in (exception descriptor *)
85 typedef void * (*__eh_matcher) PROTO ((void *, void *, void *));
87 /* This value is to be checked as a 'match all' case in the runtime field. */
89 #define CATCH_ALL_TYPE ((void *) -1)
91 /* This is the runtime exception information. This forms the minimum required
92 information for an exception info pointer in an eh_context structure. */
95 typedef struct __eh_info
97 __eh_matcher match_function;
102 /* Convienient language codes for ID the originating language. Similar
103 to the codes in dwarf2.h. */
105 enum exception_source_language
107 EH_LANG_C89 = 0x0001,
109 EH_LANG_Ada83 = 0x0003,
110 EH_LANG_C_plus_plus = 0x0004,
111 EH_LANG_Cobol74 = 0x0005,
112 EH_LANG_Cobol85 = 0x0006,
113 EH_LANG_Fortran77 = 0x0007,
114 EH_LANG_Fortran90 = 0x0008,
115 EH_LANG_Pascal83 = 0x0009,
116 EH_LANG_Modula2 = 0x000a,
117 EH_LANG_Java = 0x000b,
118 EH_LANG_Mips_Assembler = 0x8001
121 #endif /* EH_TABLE_LOOKUP */