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1 /* |
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2 * (c) 2003 Mario de Sousa |
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3 * |
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4 * Offered to the public under the terms of the GNU General Public License |
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5 * as published by the Free Software Foundation; either version 2 of the |
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6 * License, or (at your option) any later version. |
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7 * |
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8 * This program is distributed in the hope that it will be useful, but |
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9 * WITHOUT ANY WARRANTY; without even the implied warranty of |
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10 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General |
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11 * Public License for more details. |
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12 * |
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13 * This code is made available on the understanding that it will not be |
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14 * used in safety-critical situations without a full and competent review. |
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15 */ |
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16 |
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17 /* |
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18 * An IEC 61131-3 IL and ST compiler. |
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19 * |
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20 * Based on the |
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21 * FINAL DRAFT - IEC 61131-3, 2nd Ed. (2001-12-10) |
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22 * |
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23 */ |
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24 |
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25 |
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26 /* Returns the function block type declaration |
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27 * of a specific function block instance. |
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28 */ |
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29 |
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30 |
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31 |
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32 /* Returns the type name of a specific function block |
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33 * instance. This class will search the variable |
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34 * declarations inside the scope given to it |
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35 * searching for the declaration of the function |
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36 * block instance. |
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37 * |
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38 * The class constructor must be given the search scope |
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39 * (function, function block or program within which |
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40 * the function block instance was declared). |
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41 * |
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42 * This class will search the tree from the root given to the |
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43 * constructor. Another option would be to build a symbol table, |
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44 * and search that instead. Building the symbol table would be done |
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45 * while visiting the variable declaration objects in the parse |
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46 * tree. Unfortuantely, generate_cc_c does not visit these |
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47 * objects, delegating it to another class. This means that |
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48 * we would need another specialised class just to build the |
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49 * symbol table. We might just as well have a specialised class |
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50 * that searches the tree itself for the relevant info. This |
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51 * class is exactly that...! |
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52 */ |
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53 class search_fb_instance_decl_c: public search_visitor_c { |
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54 |
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55 private: |
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56 symbol_c *search_scope; |
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57 |
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58 symbol_c *search_name; |
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59 symbol_c *current_fb_type_name; |
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60 |
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61 public: |
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62 search_fb_instance_decl_c(symbol_c *search_scope) { |
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63 this->search_scope = search_scope; |
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64 this->current_fb_type_name = NULL; |
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65 } |
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66 |
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67 symbol_c *get_type_name(symbol_c *fb_instance_name) { |
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68 this->search_name = fb_instance_name; |
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69 return (symbol_c *)search_scope->accept(*this); |
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70 } |
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71 |
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72 public: |
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73 /***************************/ |
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74 /* B 0 - Programming Model */ |
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75 /***************************/ |
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76 void *visit(library_c *symbol) { |
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77 /* we do not want to search multiple declaration scopes, |
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78 * so we do not visit all the functions, fucntion blocks, etc... |
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79 */ |
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80 return NULL; |
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81 } |
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82 |
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83 /******************************************/ |
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84 /* B 1.4.3 - Declaration & Initialisation */ |
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85 /******************************************/ |
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86 |
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87 /* name_list ':' function_block_type_name ASSIGN structure_initialization */ |
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88 /* structure_initialization -> may be NULL ! */ |
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89 void *visit(fb_name_decl_c *symbol) { |
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90 current_fb_type_name = symbol->function_block_type_name; |
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91 return symbol->fb_name_list->accept(*this); |
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92 } |
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93 |
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94 /* name_list ',' fb_name */ |
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95 void *visit(fb_name_list_c *symbol) { |
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96 list_c *list = symbol; |
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97 for(int i = 0; i < list->n; i++) { |
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98 if (compare_identifiers(list->elements[i], search_name) == 0) |
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99 /* by now, current_fb_declaration should be != NULL */ |
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100 return current_fb_type_name; |
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101 } |
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102 return NULL; |
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103 } |
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104 |
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105 /**************************************/ |
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106 /* B.1.5 - Program organization units */ |
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107 /**************************************/ |
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108 /***********************/ |
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109 /* B 1.5.1 - Functions */ |
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110 /***********************/ |
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111 void *visit(function_declaration_c *symbol) { |
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112 /* no need to search through all the body, so we only |
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113 * visit the variable declarations...! |
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114 */ |
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115 return symbol->var_declarations_list->accept(*this); |
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116 } |
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117 |
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118 /*****************************/ |
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119 /* B 1.5.2 - Function Blocks */ |
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120 /*****************************/ |
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121 void *visit(function_block_declaration_c *symbol) { |
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122 /* no need to search through all the body, so we only |
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123 * visit the variable declarations...! |
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124 */ |
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125 return symbol->var_declarations->accept(*this); |
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126 } |
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127 |
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128 /**********************/ |
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129 /* B 1.5.3 - Programs */ |
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130 /**********************/ |
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131 void *visit(program_declaration_c *symbol) { |
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132 /* no need to search through all the body, so we only |
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133 * visit the variable declarations...! |
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134 */ |
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135 return symbol->var_declarations->accept(*this); |
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136 } |
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137 }; |
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138 |
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139 |
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140 |
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141 |