EdkCompatibilityPkg/Sample/Tools/Source/ProcessDsc/Exceptions.c

   1 /*++
   2
   3 Copyright (c) 2004, Intel Corporation. All rights reserved.<BR>
   4 This program and the accompanying materials
   5 are licensed and made available under the terms and conditions of the BSD License
   6 which accompanies this distribution.  The full text of the license may be found at
   7 http://opensource.org/licenses/bsd-license.php
   8
   9 THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
  10 WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
  11
  12 Module Name:
  13
  14   Exceptions.c
  15
  16 Abstract:
  17
  18   Exception logging routines.
  19
  20 --*/
  21
  22 #include <stdio.h>
  23 #include <stdlib.h>
  24 #include <string.h> // for memset()
  25 #include "Exceptions.h"
  26
  27 //
  28 // Max length of a saved exception message
  29 //
  30 #define MAX_EXCEPTION_MSG 200
  31
  32 //
  33 // We use this structure to track exceptions thrown. We nest deeper on
  34 // TryException() calls, and come back out on CatchException() calls.
  35 // We save off the first exception message for a given exception level,
  36 // but we save the count of how many were thrown.
  37 //
  38 typedef struct {
  39   int   ExceptionCount;
  40   char  ExceptionMsg[MAX_EXCEPTION_MSG];
  41 } EXCEPTION_LOG;
  42
  43 static EXCEPTION_LOG  ExceptionLog[MAX_EXCEPTION_NESTING + 1];
  44 static int            ExceptionLevel;
  45
  46 //
  47 // Initialize our data and structures for tracking exceptions.
  48 //
  49 int
  50 InitExceptions (
  51   VOID
  52   )
  53 {
  54   ExceptionLevel = -1;
  55   memset ((char *) &ExceptionLog, 0, sizeof (ExceptionLog));
  56   return 0;
  57 }
  58 //
  59 // This function replaces the _try() exception macro. It sets the
  60 // nesting level.
  61 //
  62 int
  63 TryException (
  64   VOID
  65   )
  66 {
  67   //
  68   // Boost our exception level if we would not go out of range
  69   //
  70   ExceptionLevel++;
  71   if (ExceptionLevel >= MAX_EXCEPTION_NESTING) {
  72     fprintf (stderr, "ERROR: Max exception nesting level exceeded\n");
  73     ExceptionLevel--;
  74     return 1;
  75   }
  76
  77   return 0;
  78 }
  79 //
  80 // This function replaces the _catch() exception macro. It's used to decrement
  81 // the nesting level and return any exeption error messages that were
  82 // thrown at the current nesting level.
  83 //
  84 char *
  85 CatchException (
  86   VOID
  87   )
  88 {
  89   //
  90   // Return a pointer to exception message. NULL if no exceptions at this level
  91   //
  92   if (ExceptionLevel >= 0) {
  93     ExceptionLevel--;
  94     if (ExceptionLog[ExceptionLevel + 1].ExceptionMsg[0]) {
  95       return ExceptionLog[ExceptionLevel + 1].ExceptionMsg;
  96     } else {
  97       return NULL;
  98     }
  99   } else {
 100     fprintf (stderr, "ERROR: Invalid nesting level call to CatchException()\n");
 101     return NULL;
 102   }
 103 }
 104 //
 105 // This function can be used to test for exceptions between the TryException()
 106 // and CatchException() calls in a given function.
 107 //
 108 int
 109 ExceptionThrown (
 110   VOID
 111   )
 112 {
 113   return ExceptionLog[ExceptionLevel].ExceptionCount;
 114 }
 115 //
 116 // This function replaces the _throw() exception macro. It saves off the
 117 // given error message at the current exeption level nesting.
 118 //
 119 int
 120 ThrowException (
 121   char *Msg
 122   )
 123 {
 124   if (ExceptionLevel < 0) {
 125     //
 126     // fprintf (stderr, "ERROR: Exception thrown out of scope");
 127     // Haven't yet enabled handling of exceptions, so just emit the message.
 128     //
 129     fprintf (stderr, Msg);
 130     return 1;
 131   }
 132   //
 133   // Only log the first
 134   //
 135   if (ExceptionLog[ExceptionLevel].ExceptionMsg[0] == 0) {
 136     strncpy (ExceptionLog[ExceptionLevel].ExceptionMsg, Msg, MAX_EXCEPTION_MSG);
 137   }
 138
 139   ExceptionLog[ExceptionLevel].ExceptionCount++;
 140   return 0;
 141 }