mcs/class/Microsoft.JScript/Microsoft.JScript/Try.cs

   1 //
   2 // Try.cs:
   3 //
   4 // Author: Cesar Octavio Lopez Nataren
   5 //
   6 // (C) 2003, 2004, Cesar Octavio Lopez Nataren
   7 //
   8
   9 //
  10 // Permission is hereby granted, free of charge, to any person obtaining
  11 // a copy of this software and associated documentation files (the
  12 // "Software"), to deal in the Software without restriction, including
  13 // without limitation the rights to use, copy, modify, merge, publish,
  14 // distribute, sublicense, and/or sell copies of the Software, and to
  15 // permit persons to whom the Software is furnished to do so, subject to
  16 // the following conditions:
  17 //
  18 // The above copyright notice and this permission notice shall be
  19 // included in all copies or substantial portions of the Software.
  20 //
  21 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
  22 // EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
  23 // MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
  24 // NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
  25 // LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
  26 // OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
  27 // WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
  28 //
  29
  30 using System;
  31 using Microsoft.JScript.Vsa;
  32 using System.Reflection;
  33 using System.Reflection.Emit;
  34 using System.Collections;
  35
  36 namespace Microsoft.JScript {
  37
  38         public sealed class Try : AST, ICanModifyContext {
  39
  40                 internal FieldBuilder field_info;
  41                 internal LocalBuilder local_builder;
  42
  43                 internal AST guarded_block;
  44                 internal ArrayList catch_blocks;
  45                 internal AST finally_block;
  46
  47
  48                 internal Try (AST guarded_block, ArrayList catch_block, AST finally_block, AST parent, Location location)
  49                         : base (parent, location)
  50                 {
  51                         this.guarded_block = guarded_block;
  52                         this.catch_blocks = catch_block;
  53                         this.finally_block = finally_block;
  54                 }
  55
  56                 public static Object JScriptExceptionValue (object e, VsaEngine engine)
  57                 {
  58                         Exception exc = e as Exception;
  59                         string message = null;
  60                         if (exc != null)
  61                                 message = exc.Message;
  62                         else
  63                                 message = String.Format ("Unknown exception of type {0}", exc.GetType ());
  64                         return new ErrorObject (message);
  65                 }
  66
  67                 public static void PushHandlerScope (VsaEngine engine, string id, int scopeId)
  68                 {
  69                         throw new NotImplementedException ();
  70                 }
  71
  72                 internal override bool Resolve (Environment env)
  73                 {
  74                         bool r = true;
  75                         if (guarded_block != null)
  76                                 r &= guarded_block.Resolve (env);
  77
  78                         if (catch_blocks != null && catch_blocks.Count > 0) {
  79                                 foreach (Catch c in catch_blocks) {
  80                                         env.BeginScope (String.Empty, true);
  81                                         env.Enter (String.Empty, Symbol.CreateSymbol (c.id), c);
  82                                         r &= c.Resolve (env);
  83                                         env.EndScope (String.Empty);
  84                                 }
  85                         }
  86                         if (finally_block != null)
  87                                 r &= finally_block.Resolve (env);
  88                         return r;
  89                 }
  90
  91                 internal override void Emit (EmitContext ec)
  92                 {
  93                         ILGenerator ig = ec.ig;
  94
  95                         ig.BeginExceptionBlock ();
  96
  97                         if (guarded_block != null)
  98                                 guarded_block.Emit (ec);
  99
 100                         if (catch_blocks != null && catch_blocks.Count > 0) {
 101                                 foreach (Catch c in catch_blocks)
 102                                         c.Emit (ec);
 103                         }
 104                         if (finally_block != null) {
 105                                 ig.BeginFinallyBlock ();
 106                                 finally_block.Emit (ec);
 107                         }
 108                         ig.EndExceptionBlock ();
 109                 }
 110
 111
 112                 void ICanModifyContext.PopulateContext (Environment env, string ns)
 113                 {
 114                         if (guarded_block is ICanModifyContext)
 115                                 ((ICanModifyContext) guarded_block).PopulateContext (env, ns);
 116
 117                         foreach (AST ast in catch_blocks)
 118                                 if (ast is ICanModifyContext)
 119                                         ((ICanModifyContext) ast).PopulateContext (env, ns);
 120
 121                         if (finally_block is ICanModifyContext)
 122                                 ((ICanModifyContext) finally_block).PopulateContext (env, ns);
 123                 }
 124
 125                 void ICanModifyContext.EmitDecls (EmitContext ec)
 126                 {
 127                         if (guarded_block is ICanModifyContext)
 128                                 ((ICanModifyContext) guarded_block).EmitDecls (ec);
 129
 130                         foreach (AST ast in catch_blocks)
 131                                 if (ast is ICanModifyContext)
 132                                         ((ICanModifyContext) ast).EmitDecls (ec);
 133
 134                         if (finally_block is ICanModifyContext)
 135                                 ((ICanModifyContext) finally_block).EmitDecls (ec);
 136                 }
 137         }
 138 }