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/*
* %CopyrightBegin%
*
* Copyright Ericsson AB 1996-2010. All Rights Reserved.
*
* The contents of this file are subject to the Erlang Public License,
* Version 1.1, (the "License"); you may not use this file except in
* compliance with the License. You should have received a copy of the
* Erlang Public License along with this software. If not, it can be
* retrieved online at http://www.erlang.org/.
*
* Software distributed under the License is distributed on an "AS IS"
* basis, WITHOUT WARRANTY OF ANY KIND, either express or implied. See
* the License for the specific language governing rights and limitations
* under the License.
*
* %CopyrightEnd%
*/
#ifndef __ERROR_H__
#define __ERROR_H__
/*
* There are three primary exception classes:
*
* - exit Process termination - not an error.
* - error Error (adds stacktrace; will be logged).
* - thrown Nonlocal return (turns into a 'nocatch'
* error if not caught by the process).
*
* In addition, we define a number of exit codes as a convenient
* short-hand: instead of building the error descriptor term at the time
* the exception is raised, it is built as necessary when the exception
* is handled. Examples are EXC_NORMAL, EXC_BADARG, EXC_BADARITH, etc.
* Some of these have convenient aliases, like BADARG and BADARITH.
*/
/*
* Bits 0-1 index the 'exception class tag' table.
*/
#define EXC_CLASSBITS 3
#define GET_EXC_CLASS(x) ((x) & EXC_CLASSBITS)
/*
* Exception class tags (indices into the 'exception_tag' array)
*/
#define EXTAG_ERROR 0
#define EXTAG_EXIT 1
#define EXTAG_THROWN 2
#define NUMBER_EXC_TAGS 3 /* The number of exception class tags */
/*
* Exit code flags (bits 2-7)
*
* These flags make is easier and quicker to decide what to do with the
* exception in the early stages, before a handler is found, and also
* maintains some separation between the class tag and the actions.
*/
#define EXF_PANIC (1<<2) /* ignore catches */
#define EXF_THROWN (1<<3) /* nonlocal return */
#define EXF_LOG (1<<4) /* write to logger on termination */
#define EXF_NATIVE (1<<5) /* occurred in native code */
#define EXF_SAVETRACE (1<<6) /* save stack trace in internal form */
#define EXF_ARGLIST (1<<7) /* has arglist for top of trace */
#define EXC_FLAGBITS 0x00fc
/*
* The primary fields of an exception code
*/
#define EXF_PRIMARY (EXF_PANIC | EXF_THROWN | EXF_LOG | EXF_NATIVE)
#define PRIMARY_EXCEPTION(x) ((x) & (EXF_PRIMARY | EXC_CLASSBITS))
#define NATIVE_EXCEPTION(x) ((x) | EXF_NATIVE)
/*
* Bits 8-12 of the error code are used for indexing into
* the short-hand error descriptor table.
*/
#define EXC_INDEXBITS 0x1f00
#define GET_EXC_INDEX(x) (((x) & EXC_INDEXBITS) >> 8)
/*
* Exit codes used for raising a fresh exception. The primary exceptions
* share index 0 in the descriptor table. EXC_NULL signals that no
* exception has occurred. The primary exit codes EXC_EXIT, EXC_ERROR
* and EXC_THROWN are the basis for all other exit codes, and must
* always have the EXF_SAVETRACE flag set so that a trace is saved
* whenever a new exception occurs; the flag is then cleared.
*/
#define EXC_NULL 0 /* Initial value for p->freason */
#define EXC_PRIMARY (0 | EXF_SAVETRACE)
#define EXC_ERROR (EXC_PRIMARY | EXTAG_ERROR | EXF_LOG)
/* Generic error (exit term
* in p->fvalue) */
#define EXC_EXIT (EXC_PRIMARY | EXTAG_EXIT)
/* Generic exit (exit term
* in p->fvalue) */
#define EXC_THROWN (EXC_PRIMARY | EXTAG_THROWN | EXF_THROWN)
/* Generic nonlocal return
* (thrown term in p->fvalue) */
#define EXC_ERROR_2 (EXC_ERROR | EXF_ARGLIST)
/* Error with given arglist term
* (exit reason in p->fvalue) */
#define EXC_NORMAL ((1 << 8) | EXC_EXIT)
/* Normal exit (reason 'normal') */
#define EXC_INTERNAL_ERROR ((2 << 8) | EXC_ERROR | EXF_PANIC)
/* Things that shouldn't happen */
#define EXC_BADARG ((3 << 8) | EXC_ERROR)
/* Bad argument to a BIF */
#define EXC_BADARITH ((4 << 8) | EXC_ERROR)
/* Bad arithmetic */
#define EXC_BADMATCH ((5 << 8) | EXC_ERROR)
/* Bad match in function body */
#define EXC_FUNCTION_CLAUSE ((6 << 8) | EXC_ERROR)
/* No matching function head */
#define EXC_CASE_CLAUSE ((7 << 8) | EXC_ERROR)
/* No matching case clause */
#define EXC_IF_CLAUSE ((8 << 8) | EXC_ERROR)
/* No matching if clause */
#define EXC_UNDEF ((9 << 8) | EXC_ERROR)
/* No farity that matches */
#define EXC_BADFUN ((10 << 8) | EXC_ERROR)
/* Not an existing fun */
#define EXC_BADARITY ((11 << 8) | EXC_ERROR)
/* Attempt to call fun with
* wrong number of arguments. */
#define EXC_TIMEOUT_VALUE ((12 << 8) | EXC_ERROR)
/* Bad time out value */
#define EXC_NOPROC ((13 << 8) | EXC_ERROR)
/* No process or port */
#define EXC_NOTALIVE ((14 << 8) | EXC_ERROR)
/* Not distributed */
#define EXC_SYSTEM_LIMIT ((15 << 8) | EXC_ERROR)
/* Ran out of something */
#define EXC_TRY_CLAUSE ((16 << 8) | EXC_ERROR)
/* No matching try clause */
#define EXC_NOTSUP ((17 << 8) | EXC_ERROR)
/* Not supported */
#define NUMBER_EXIT_CODES 18 /* The number of exit code indices */
/*
* Internal pseudo-error codes.
*/
#define TRAP (1 << 8) /* BIF Trap to erlang code */
/*
* Aliases for some common exit codes.
*/
#define BADARG EXC_BADARG
#define BADARITH EXC_BADARITH
#define BADMATCH EXC_BADMATCH
#define SYSTEM_LIMIT EXC_SYSTEM_LIMIT
/*
* Pseudo error codes (these are never seen by the user).
*/
#define TLOAD_OK 0 /* The threaded code linking was successful */
#define TLOAD_MAGIC_NUMBER 1 /* Wrong kind of object file */
#define TLOAD_FORMAT 2 /* Format error while reading object code */
#define TLOAD_MODULE 3 /* Module name in object code does not match */
#define TLOAD_SIZE 4 /* Given size in object code differs from actual size */
/*
* The exception stack trace parameters.
*/
#define MAX_BACKTRACE_SIZE 64 /* whatever - just not too huge */
#define DEFAULT_BACKTRACE_SIZE 8
/*
* The table translating an exception code to an atom.
*/
extern Eterm error_atom[NUMBER_EXIT_CODES];
/*
* The exception tag table.
*/
extern Eterm exception_tag[NUMBER_EXC_TAGS];
/*
* The quick-saved stack trace structure
*/
struct StackTrace {
Eterm header; /* bignum header - must be first in struct */
Eterm freason; /* original exception reason is saved in the struct */
BeamInstr* pc;
BeamInstr* current;
int depth; /* number of saved pointers in trace[] */
BeamInstr *trace[1]; /* varying size - must be last in struct */
};
#endif /* __ERROR_H__ */
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