derelict.util.exception source code

1 /*
2 
3 Boost Software License - Version 1.0 - August 17th, 2003
4 
5 Permission is hereby granted, free of charge, to any person or organization
6 obtaining a copy of the software and accompanying documentation covered by
7 this license (the "Software") to use, reproduce, display, distribute,
8 execute, and transmit the Software, and to prepare derivative works of the
9 Software, and to permit third-parties to whom the Software is furnished to
10 do so, all subject to the following:
11 
12 The copyright notices in the Software and this entire statement, including
13 the above license grant, this restriction and the following disclaimer,
14 must be included in all copies of the Software, in whole or in part, and
15 all derivative works of the Software, unless such copies or derivative
16 works are solely in the form of machine-executable object code generated by
17 a source language processor.
18 
19 THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
20 IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
21 FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
22 SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
23 FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
24 ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
25 DEALINGS IN THE SOFTWARE.
26 
27 */
28 module derelict.util.exception;
29 
30 private
31 {
32     import derelict.util.compat;
33 }
34 
35 /**
36 * Base class for all exceptions thrown by Derelict packages.
37 */
38 class DerelictException : Exception
39 {
40 public:
41     this(string msg)
42     {
43         super(msg);
44     }
45 }
46 
47 /**
48 * Helper struct to facilitate throwing a single SharedLibException after failing
49 * to load a library using multiple names.
50 */
51 struct FailedSharedLib
52 {
53     string name;
54     string reason;
55 }
56 
57 /**
58 * This exception is thrown when a shared library cannot be loaded
59 * because it is either missing or not on the system path.
60 */
61 class SharedLibLoadException : DerelictException
62 {
63 public:
64     static void throwNew(in char[][] libNames, in char[][] reasons)
65     {
66         string msg = "Failed to load one or more shared libraries:";
67         foreach(i, n; libNames)
68         {
69             msg ~= "\n\t" ~ n ~ " - ";
70             if(i < reasons.length)
71                 msg ~= reasons[i];
72             else
73                 msg ~= "Unknown";
74         }
75         throw new SharedLibLoadException(msg);
76     }
77 
78     this(string msg)
79     {
80         super(msg);
81         _sharedLibName = "";
82     }
83 
84     this(string msg, string sharedLibName)
85     {
86         super(msg);
87         _sharedLibName = sharedLibName;
88     }
89 
90     string sharedLibName()
91     {
92         return _sharedLibName;
93     }
94 
95 private:
96     string _sharedLibName;
97 }
98 
99 /**
100 * This exception is thrown when a symbol cannot be loaded from a shared library,
101 * either because it does not exist in the library or because the library is corrupt.
102 */
103 class SymbolLoadException : DerelictException
104 {
105 public:
106     this(string msg)
107     {
108         super(msg);
109     }
110 
111     this(string sharedLibName, string symbolName)
112     {
113         super("Failed to load symbol " ~ symbolName ~ " from shared library " ~ sharedLibName);
114         _symbolName = symbolName;
115     }
116 
117     string symbolName()
118     {
119         return _symbolName;
120     }
121 
122 private:
123     string _symbolName;
124 }
125 
126 alias SymbolLoadException SharedLibProcLoadException;
127 
128 //******************************************************************************
129 
130 /**
131 * The MissingSymbolCallback allows the app to handle the case of missing symbols. By default,
132 * a SharedLibSymbolLoadException is thrown. However, if a the app determines that
133 * particular symbol is not needed, the callback can return true. This will cause
134 * the shared library to continue loading. Returning false will cause the exception
135 * to be thrown.
136 */
137 alias bool function(string libName, string symbolName) MissingSymbolCallback;
138 alias MissingSymbolCallback MissingProcCallback;
139 
140 private MissingSymbolCallback missingSymbolCallback;
141 
142 public void Derelict_HandleMissingSymbol(string libName, string symbolName)
143 {
144     bool result = false;
145     if(missingSymbolCallback !is null)
146         result = missingSymbolCallback(libName, symbolName);
147     if(!result)
148         throw new SymbolLoadException(libName, symbolName);
149 }
150 alias Derelict_HandleMissingSymbol Derelict_HandleMissingProc;
151 
152 void Derelict_SetMissingSymbolCallback(MissingSymbolCallback callback)
153 {
154     missingSymbolCallback = callback;
155 }
156 alias Derelict_SetMissingSymbolCallback Derelict_SetMissingProcCallback;