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+/*
+ * %CopyrightBegin%
+ *
+ * Copyright Ericsson AB 1996-2009. 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 */
+ Eterm* pc;
+ Eterm* current;
+ int depth; /* number of saved pointers in trace[] */
+ Eterm *trace[1]; /* varying size - must be last in struct */
+};
+
+#endif /* __ERROR_H__ */