1 | // |
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2 | // Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo |
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3 | // |
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4 | // The contents of this file are covered under the licence agreement in the |
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5 | // file "LICENCE" distributed with Cforall. |
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6 | // |
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7 | // ExceptVisitor.cc -- |
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8 | // |
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9 | // Author : Andrew Beach |
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10 | // Created On : Wed Jun 14 16:49:00 2017 |
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11 | // Last Modified By : Andrew Beach |
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12 | // Last Modified On : Wed Aug 02 12:09:00 2017 |
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13 | // Update Count : 7 |
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14 | // |
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15 | |
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16 | #include "ExceptTranslate.h" |
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17 | #include "Common/PassVisitor.h" |
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18 | #include "SynTree/Statement.h" |
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19 | #include "SynTree/Declaration.h" |
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20 | #include "SynTree/Expression.h" |
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21 | #include "SynTree/Type.h" |
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22 | #include "SynTree/Attribute.h" |
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23 | #include "SynTree/VarExprReplacer.h" |
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24 | |
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25 | namespace ControlStruct { |
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26 | |
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27 | // Buricratic Helpers (Not having to do with the paritular operation.) |
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28 | |
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29 | typedef std::list<CatchStmt*> CatchList; |
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30 | |
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31 | void split( CatchList& allHandlers, CatchList& terHandlers, |
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32 | CatchList& resHandlers ) { |
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33 | while ( !allHandlers.empty() ) { |
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34 | CatchStmt * stmt = allHandlers.front(); |
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35 | allHandlers.pop_front(); |
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36 | if (CatchStmt::Terminate == stmt->get_kind()) { |
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37 | terHandlers.push_back(stmt); |
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38 | } else { |
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39 | resHandlers.push_back(stmt); |
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40 | } |
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41 | } |
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42 | } |
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43 | |
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44 | void appendDeclStmt( CompoundStmt * block, Declaration * item ) { |
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45 | block->push_back(new DeclStmt(noLabels, item)); |
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46 | } |
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47 | |
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48 | Expression * nameOf( DeclarationWithType * decl ) { |
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49 | return new VariableExpr( decl ); |
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50 | } |
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51 | |
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52 | class ExceptionMutatorCore : public WithGuards { |
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53 | enum Context { NoHandler, TerHandler, ResHandler }; |
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54 | |
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55 | // Also need to handle goto, break & continue. |
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56 | // They need to be cut off in a ResHandler, until we enter another |
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57 | // loop, switch or the goto stays within the function. |
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58 | |
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59 | Context cur_context; |
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60 | |
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61 | // The current (innermost) termination handler exception declaration. |
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62 | ObjectDecl * handler_except_decl; |
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63 | |
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64 | // The built in types used in translation. |
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65 | StructDecl * except_decl; |
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66 | StructDecl * node_decl; |
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67 | StructDecl * hook_decl; |
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68 | |
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69 | // The many helper functions for code/syntree generation. |
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70 | Statement * create_given_throw( |
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71 | const char * throwFunc, ThrowStmt * throwStmt ); |
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72 | Statement * create_terminate_throw( ThrowStmt * throwStmt ); |
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73 | Statement * create_terminate_rethrow( ThrowStmt * throwStmt ); |
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74 | Statement * create_resume_throw( ThrowStmt * throwStmt ); |
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75 | Statement * create_resume_rethrow( ThrowStmt * throwStmt ); |
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76 | CompoundStmt * take_try_block( TryStmt * tryStmt ); |
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77 | FunctionDecl * create_try_wrapper( CompoundStmt * body ); |
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78 | FunctionDecl * create_terminate_catch( CatchList &handlers ); |
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79 | CompoundStmt * create_single_matcher( |
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80 | DeclarationWithType * except_obj, CatchStmt * modded_handler ); |
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81 | FunctionDecl * create_terminate_match( CatchList &handlers ); |
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82 | CompoundStmt * create_terminate_caller( FunctionDecl * try_wrapper, |
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83 | FunctionDecl * terminate_catch, FunctionDecl * terminate_match ); |
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84 | FunctionDecl * create_resume_handler( CatchList &handlers ); |
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85 | CompoundStmt * create_resume_wrapper( |
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86 | Statement * wraps, FunctionDecl * resume_handler ); |
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87 | FunctionDecl * create_finally_wrapper( TryStmt * tryStmt ); |
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88 | ObjectDecl * create_finally_hook( FunctionDecl * finally_wrapper ); |
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89 | |
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90 | // Types used in translation, make sure to use clone. |
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91 | // void (*function)(); |
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92 | FunctionType try_func_t; |
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93 | // void (*function)(int, exception); |
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94 | FunctionType catch_func_t; |
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95 | // int (*function)(exception); |
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96 | FunctionType match_func_t; |
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97 | // bool (*function)(exception); |
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98 | FunctionType handle_func_t; |
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99 | // void (*function)(__attribute__((unused)) void *); |
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100 | FunctionType finally_func_t; |
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101 | |
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102 | StructInstType * create_except_type() { |
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103 | assert( except_decl ); |
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104 | return new StructInstType( noQualifiers, except_decl ); |
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105 | } |
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106 | void init_func_types(); |
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107 | |
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108 | public: |
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109 | ExceptionMutatorCore() : |
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110 | cur_context( NoHandler ), |
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111 | handler_except_decl( nullptr ), |
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112 | except_decl( nullptr ), node_decl( nullptr ), hook_decl( nullptr ), |
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113 | try_func_t( noQualifiers, false ), |
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114 | catch_func_t( noQualifiers, false ), |
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115 | match_func_t( noQualifiers, false ), |
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116 | handle_func_t( noQualifiers, false ), |
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117 | finally_func_t( noQualifiers, false ) |
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118 | { |
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119 | init_func_types(); |
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120 | } |
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121 | |
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122 | void premutate( CatchStmt *catchStmt ); |
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123 | void premutate( StructDecl *structDecl ); |
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124 | Statement * postmutate( ThrowStmt *throwStmt ); |
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125 | Statement * postmutate( TryStmt *tryStmt ); |
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126 | }; |
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127 | |
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128 | void ExceptionMutatorCore::init_func_types() { |
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129 | ObjectDecl index_obj( |
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130 | "__handler_index", |
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131 | Type::StorageClasses(), |
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132 | LinkageSpec::Cforall, |
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133 | /*bitfieldWidth*/ NULL, |
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134 | new BasicType( noQualifiers, BasicType::SignedInt ), |
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135 | /*init*/ NULL |
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136 | ); |
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137 | ObjectDecl exception_obj( |
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138 | "__exception_inst", |
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139 | Type::StorageClasses(), |
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140 | LinkageSpec::Cforall, |
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141 | /*bitfieldWidth*/ NULL, |
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142 | new PointerType( |
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143 | noQualifiers, |
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144 | //new StructInstType( noQualifiers, except_decl ) |
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145 | new BasicType( noQualifiers, BasicType::SignedInt ) |
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146 | ), |
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147 | /*init*/ NULL |
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148 | ); |
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149 | ObjectDecl bool_obj( |
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150 | "__ret_bool", |
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151 | Type::StorageClasses(), |
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152 | LinkageSpec::Cforall, |
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153 | /*bitfieldWidth*/ NULL, |
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154 | new BasicType( noQualifiers, BasicType::Bool ), |
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155 | /*init*/ NULL |
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156 | ); |
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157 | ObjectDecl voidptr_obj( |
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158 | "__hook", |
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159 | Type::StorageClasses(), |
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160 | LinkageSpec::Cforall, |
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161 | NULL, |
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162 | new PointerType( |
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163 | noQualifiers, |
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164 | new VoidType( |
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165 | noQualifiers |
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166 | ), |
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167 | std::list<Attribute *>{ new Attribute( "unused" ) } |
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168 | ), |
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169 | NULL |
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170 | ); |
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171 | |
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172 | catch_func_t.get_parameters().push_back( index_obj.clone() ); |
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173 | catch_func_t.get_parameters().push_back( exception_obj.clone() ); |
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174 | match_func_t.get_returnVals().push_back( index_obj.clone() ); |
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175 | match_func_t.get_parameters().push_back( exception_obj.clone() ); |
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176 | handle_func_t.get_returnVals().push_back( bool_obj.clone() ); |
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177 | handle_func_t.get_parameters().push_back( exception_obj.clone() ); |
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178 | finally_func_t.get_parameters().push_back( voidptr_obj.clone() ); |
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179 | } |
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180 | |
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181 | // ThrowStmt Mutation Helpers |
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182 | |
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183 | Statement * ExceptionMutatorCore::create_given_throw( |
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184 | const char * throwFunc, ThrowStmt * throwStmt ) { |
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185 | // There is an extra copy here we might be able to remove with |
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186 | // references. |
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187 | // { int NAME = EXPR; throwFunc( &NAME ); } |
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188 | CompoundStmt * result = new CompoundStmt( noLabels ); |
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189 | ObjectDecl * local = new ObjectDecl( |
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190 | "__local_exception_copy", |
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191 | Type::StorageClasses(), |
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192 | LinkageSpec::Cforall, |
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193 | NULL, |
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194 | new BasicType( noQualifiers, BasicType::SignedInt ), |
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195 | new SingleInit( throwStmt->get_expr() ) |
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196 | ); |
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197 | appendDeclStmt( result, local ); |
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198 | UntypedExpr * call = new UntypedExpr( new NameExpr( throwFunc ) ); |
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199 | call->get_args().push_back( new AddressExpr( nameOf( local ) ) ); |
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200 | result->push_back( new ExprStmt( throwStmt->get_labels(), call ) ); |
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201 | throwStmt->set_expr( nullptr ); |
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202 | delete throwStmt; |
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203 | return result; |
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204 | } |
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205 | |
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206 | Statement * ExceptionMutatorCore::create_terminate_throw( |
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207 | ThrowStmt *throwStmt ) { |
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208 | // { int NAME = EXPR; __throw_terminate( &NAME ); } |
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209 | return create_given_throw( "__cfaehm__throw_terminate", throwStmt ); |
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210 | } |
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211 | |
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212 | Statement * ExceptionMutatorCore::create_terminate_rethrow( |
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213 | ThrowStmt *throwStmt ) { |
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214 | // { `handler_except_decl` = NULL; __rethrow_terminate(); } |
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215 | assert( nullptr == throwStmt->get_expr() ); |
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216 | assert( handler_except_decl ); |
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217 | |
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218 | CompoundStmt * result = new CompoundStmt( throwStmt->get_labels() ); |
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219 | result->push_back( new ExprStmt( noLabels, UntypedExpr::createAssign( |
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220 | nameOf( handler_except_decl ), |
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221 | new ConstantExpr( Constant::null( |
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222 | new PointerType( |
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223 | noQualifiers, |
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224 | handler_except_decl->get_type()->clone() |
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225 | ) |
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226 | ) ) |
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227 | ) ) ); |
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228 | result->push_back( new ExprStmt( |
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229 | noLabels, |
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230 | new UntypedExpr( new NameExpr( "__cfaehm__rethrow_terminate" ) ) |
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231 | ) ); |
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232 | delete throwStmt; |
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233 | return result; |
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234 | } |
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235 | |
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236 | Statement * ExceptionMutatorCore::create_resume_throw( |
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237 | ThrowStmt *throwStmt ) { |
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238 | // __throw_resume( EXPR ); |
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239 | return create_given_throw( "__cfaehm__throw_resume", throwStmt ); |
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240 | } |
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241 | |
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242 | Statement * ExceptionMutatorCore::create_resume_rethrow( |
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243 | ThrowStmt *throwStmt ) { |
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244 | // return false; |
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245 | Statement * result = new ReturnStmt( |
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246 | throwStmt->get_labels(), |
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247 | new ConstantExpr( Constant::from_bool( false ) ) |
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248 | ); |
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249 | delete throwStmt; |
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250 | return result; |
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251 | } |
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252 | |
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253 | // TryStmt Mutation Helpers |
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254 | |
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255 | // XXX: Leave out? |
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256 | CompoundStmt * ExceptionMutatorCore::take_try_block( TryStmt *tryStmt ) { |
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257 | CompoundStmt * block = tryStmt->get_block(); |
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258 | tryStmt->set_block( nullptr ); |
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259 | return block; |
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260 | } |
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261 | |
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262 | FunctionDecl * ExceptionMutatorCore::create_try_wrapper( |
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263 | CompoundStmt *body ) { |
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264 | |
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265 | return new FunctionDecl( "try", Type::StorageClasses(), |
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266 | LinkageSpec::Cforall, try_func_t.clone(), body ); |
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267 | } |
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268 | |
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269 | FunctionDecl * ExceptionMutatorCore::create_terminate_catch( |
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270 | CatchList &handlers ) { |
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271 | std::list<CaseStmt *> handler_wrappers; |
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272 | |
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273 | FunctionType *func_type = catch_func_t.clone(); |
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274 | DeclarationWithType * index_obj = func_type->get_parameters().front(); |
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275 | DeclarationWithType * except_obj = func_type->get_parameters().back(); |
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276 | |
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277 | // Index 1..{number of handlers} |
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278 | int index = 0; |
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279 | CatchList::iterator it = handlers.begin(); |
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280 | for ( ; it != handlers.end() ; ++it ) { |
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281 | ++index; |
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282 | CatchStmt * handler = *it; |
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283 | |
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284 | // INTEGERconstant Version |
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285 | // case `index`: |
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286 | // { |
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287 | // `handler.decl` {inserted} = { except_obj }; |
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288 | // `handler.body` |
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289 | // } |
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290 | // return; |
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291 | CompoundStmt * block = new CompoundStmt( noLabels ); |
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292 | |
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293 | // Just copy the exception value. (Post Validation) |
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294 | ObjectDecl * handler_decl = |
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295 | static_cast<ObjectDecl *>( handler->get_decl() ); |
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296 | ObjectDecl * local_except = handler_decl->clone(); |
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297 | local_except->set_init( |
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298 | new ListInit({ new SingleInit( nameOf( except_obj ) ) }) ); |
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299 | #if 0 |
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300 | // Virtual Exception Vision |
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301 | // case `index`: |
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302 | // { |
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303 | // `handler.decl` = { (virtual `decl.type`)`except` }; |
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304 | // `handler.body`; |
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305 | // } |
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306 | // return; |
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307 | |
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308 | // Save a cast copy of the exception (should always succeed). |
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309 | local_except->set_init( |
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310 | new ListInit({ new SingleInit( |
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311 | new VirtualCastExpr( nameOf( except_obj ), |
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312 | local_except->get_type() |
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313 | ) |
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314 | ) }) |
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315 | ); |
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316 | #endif |
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317 | block->push_back( new DeclStmt( noLabels, local_except ) ); |
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318 | |
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319 | // Add the cleanup attribute. |
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320 | local_except->get_attributes().push_back( new Attribute( |
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321 | "cleanup", |
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322 | { new NameExpr( "__cfaehm__cleanup_terminate" ) } |
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323 | ) ); |
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324 | |
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325 | // Update variables in the body to point to this local copy. |
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326 | { |
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327 | VarExprReplacer::DeclMap mapping; |
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328 | mapping[ handler_decl ] = local_except; |
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329 | VarExprReplacer mapper( mapping ); |
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330 | handler->get_body()->accept( mapper ); |
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331 | } |
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332 | |
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333 | block->push_back( handler->get_body() ); |
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334 | handler->set_body( nullptr ); |
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335 | |
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336 | std::list<Statement *> caseBody |
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337 | { block, new ReturnStmt( noLabels, nullptr ) }; |
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338 | handler_wrappers.push_back( new CaseStmt( |
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339 | noLabels, |
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340 | new ConstantExpr( Constant::from_int( index ) ), |
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341 | caseBody |
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342 | ) ); |
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343 | } |
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344 | // TODO: Some sort of meaningful error on default perhaps? |
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345 | |
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346 | std::list<Statement*> stmt_handlers; |
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347 | while ( !handler_wrappers.empty() ) { |
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348 | stmt_handlers.push_back( handler_wrappers.front() ); |
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349 | handler_wrappers.pop_front(); |
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350 | } |
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351 | |
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352 | SwitchStmt * handler_lookup = new SwitchStmt( |
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353 | noLabels, |
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354 | nameOf( index_obj ), |
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355 | stmt_handlers |
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356 | ); |
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357 | CompoundStmt * body = new CompoundStmt( noLabels ); |
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358 | body->push_back( handler_lookup ); |
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359 | |
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360 | return new FunctionDecl("catch", Type::StorageClasses(), |
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361 | LinkageSpec::Cforall, func_type, body); |
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362 | } |
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363 | |
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364 | // Create a single check from a moddified handler. |
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365 | // except_obj is referenced, modded_handler will be freed. |
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366 | CompoundStmt * ExceptionMutatorCore::create_single_matcher( |
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367 | DeclarationWithType * except_obj, CatchStmt * modded_handler ) { |
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368 | CompoundStmt * block = new CompoundStmt( noLabels ); |
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369 | |
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370 | ObjectDecl * local_except = |
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371 | dynamic_cast<ObjectDecl *>( modded_handler->get_decl() ); |
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372 | assert( local_except ); |
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373 | block->push_back( new DeclStmt( noLabels, local_except ) ); |
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374 | #if 0 |
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375 | // Virtual Exception Version |
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376 | // { |
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377 | // `modded_handler.decl` |
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378 | // if ( `decl.name = (virtual)`except` |
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379 | // [&& `modded_handler.cond`] ) { |
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380 | // `modded_handler.body` |
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381 | // } |
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382 | // } |
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383 | |
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384 | // Check for type match. |
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385 | Expression * cond = UntypedExpr::createAssign( nameOf( local_except ), |
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386 | new VirtualCastExpr( nameOf( except_obj ), |
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387 | local_except->get_type()->clone() ) ); |
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388 | #endif |
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389 | |
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390 | // INTEGERconstant Version |
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391 | // { |
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392 | // `modded_handler.decl` = *`except` |
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393 | // if ( `decl.name` == `modded_handler.cond` ) { |
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394 | // `modded_handler.body` |
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395 | // } |
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396 | // } |
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397 | ConstantExpr * number = |
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398 | dynamic_cast<ConstantExpr*>( modded_handler->get_cond() ); |
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399 | assert( number ); |
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400 | modded_handler->set_cond( nullptr ); |
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401 | |
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402 | Expression * cond; |
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403 | { |
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404 | std::list<Expression *> args; |
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405 | args.push_back( number ); |
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406 | |
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407 | std::list<Expression *> rhs_args; |
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408 | rhs_args.push_back( nameOf( except_obj ) ); |
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409 | Expression * rhs = new UntypedExpr( |
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410 | new NameExpr( "*?" ), rhs_args ); |
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411 | args.push_back( rhs ); |
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412 | |
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413 | cond = new UntypedExpr( new NameExpr( "?==?" /*???*/), args ); |
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414 | } |
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415 | |
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416 | // Add the check on the conditional if it is provided. |
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417 | if ( modded_handler->get_cond() ) { |
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418 | cond = new LogicalExpr( cond, modded_handler->get_cond() ); |
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419 | } |
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420 | // Construct the match condition. |
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421 | block->push_back( new IfStmt( noLabels, |
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422 | cond, modded_handler->get_body(), nullptr ) ); |
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423 | |
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424 | modded_handler->set_decl( nullptr ); |
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425 | modded_handler->set_cond( nullptr ); |
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426 | modded_handler->set_body( nullptr ); |
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427 | delete modded_handler; |
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428 | return block; |
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429 | } |
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430 | |
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431 | FunctionDecl * ExceptionMutatorCore::create_terminate_match( |
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432 | CatchList &handlers ) { |
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433 | // int match(exception * except) { |
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434 | // HANDLER WRAPPERS { return `index`; } |
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435 | // } |
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436 | |
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437 | CompoundStmt * body = new CompoundStmt( noLabels ); |
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438 | |
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439 | FunctionType * func_type = match_func_t.clone(); |
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440 | DeclarationWithType * except_obj = func_type->get_parameters().back(); |
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441 | |
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442 | // Index 1..{number of handlers} |
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443 | int index = 0; |
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444 | CatchList::iterator it; |
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445 | for ( it = handlers.begin() ; it != handlers.end() ; ++it ) { |
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446 | ++index; |
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447 | CatchStmt * handler = *it; |
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448 | |
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449 | // Body should have been taken by create_terminate_catch. |
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450 | assert( nullptr == handler->get_body() ); |
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451 | |
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452 | // Create new body. |
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453 | handler->set_body( new ReturnStmt( noLabels, |
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454 | new ConstantExpr( Constant::from_int( index ) ) ) ); |
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455 | |
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456 | // Create the handler. |
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457 | body->push_back( create_single_matcher( except_obj, handler ) ); |
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458 | *it = nullptr; |
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459 | } |
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460 | |
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461 | body->push_back( new ReturnStmt( noLabels, new ConstantExpr( |
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462 | Constant::from_int( 0 ) ) ) ); |
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463 | |
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464 | return new FunctionDecl("match", Type::StorageClasses(), |
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465 | LinkageSpec::Cforall, func_type, body); |
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466 | } |
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467 | |
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468 | CompoundStmt * ExceptionMutatorCore::create_terminate_caller( |
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469 | FunctionDecl * try_wrapper, |
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470 | FunctionDecl * terminate_catch, |
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471 | FunctionDecl * terminate_match ) { |
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472 | // { __cfaehm__try_terminate(`try`, `catch`, `match`); } |
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473 | |
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474 | UntypedExpr * caller = new UntypedExpr( new NameExpr( |
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475 | "__cfaehm__try_terminate" ) ); |
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476 | std::list<Expression *>& args = caller->get_args(); |
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477 | args.push_back( nameOf( try_wrapper ) ); |
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478 | args.push_back( nameOf( terminate_catch ) ); |
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479 | args.push_back( nameOf( terminate_match ) ); |
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480 | |
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481 | CompoundStmt * callStmt = new CompoundStmt( noLabels ); |
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482 | callStmt->push_back( new ExprStmt( noLabels, caller ) ); |
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483 | return callStmt; |
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484 | } |
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485 | |
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486 | FunctionDecl * ExceptionMutatorCore::create_resume_handler( |
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487 | CatchList &handlers ) { |
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488 | // bool handle(exception * except) { |
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489 | // HANDLER WRAPPERS { `hander->body`; return true; } |
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490 | // } |
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491 | CompoundStmt * body = new CompoundStmt( noLabels ); |
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492 | |
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493 | FunctionType * func_type = match_func_t.clone(); |
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494 | DeclarationWithType * except_obj = func_type->get_parameters().back(); |
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495 | |
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496 | CatchList::iterator it; |
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497 | for ( it = handlers.begin() ; it != handlers.end() ; ++it ) { |
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498 | CatchStmt * handler = *it; |
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499 | |
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500 | // Modifiy body. |
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501 | CompoundStmt * handling_code = |
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502 | dynamic_cast<CompoundStmt*>( handler->get_body() ); |
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503 | if ( ! handling_code ) { |
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504 | handling_code = new CompoundStmt( noLabels ); |
---|
505 | handling_code->push_back( handler->get_body() ); |
---|
506 | } |
---|
507 | handling_code->push_back( new ReturnStmt( noLabels, |
---|
508 | new ConstantExpr( Constant::from_bool( true ) ) ) ); |
---|
509 | handler->set_body( handling_code ); |
---|
510 | |
---|
511 | // Create the handler. |
---|
512 | body->push_back( create_single_matcher( except_obj, handler ) ); |
---|
513 | *it = nullptr; |
---|
514 | } |
---|
515 | |
---|
516 | body->push_back( new ReturnStmt( noLabels, new ConstantExpr( |
---|
517 | Constant::from_bool( false ) ) ) ); |
---|
518 | |
---|
519 | return new FunctionDecl("handle", Type::StorageClasses(), |
---|
520 | LinkageSpec::Cforall, func_type, body); |
---|
521 | } |
---|
522 | |
---|
523 | CompoundStmt * ExceptionMutatorCore::create_resume_wrapper( |
---|
524 | Statement * wraps, |
---|
525 | FunctionDecl * resume_handler ) { |
---|
526 | CompoundStmt * body = new CompoundStmt( noLabels ); |
---|
527 | |
---|
528 | // struct __try_resume_node __resume_node |
---|
529 | // __attribute__((cleanup( __cfaehm__try_resume_cleanup ))); |
---|
530 | // ** unwinding of the stack here could cause problems ** |
---|
531 | // ** however I don't think that can happen currently ** |
---|
532 | // __cfaehm__try_resume_setup( &__resume_node, resume_handler ); |
---|
533 | |
---|
534 | std::list< Attribute * > attributes; |
---|
535 | { |
---|
536 | std::list< Expression * > attr_params; |
---|
537 | attr_params.push_back( new NameExpr( |
---|
538 | "__cfaehm__try_resume_cleanup" ) ); |
---|
539 | attributes.push_back( new Attribute( "cleanup", attr_params ) ); |
---|
540 | } |
---|
541 | |
---|
542 | ObjectDecl * obj = new ObjectDecl( |
---|
543 | "__resume_node", |
---|
544 | Type::StorageClasses(), |
---|
545 | LinkageSpec::Cforall, |
---|
546 | nullptr, |
---|
547 | new StructInstType( |
---|
548 | Type::Qualifiers(), |
---|
549 | node_decl |
---|
550 | ), |
---|
551 | nullptr, |
---|
552 | attributes |
---|
553 | ); |
---|
554 | appendDeclStmt( body, obj ); |
---|
555 | |
---|
556 | UntypedExpr *setup = new UntypedExpr( new NameExpr( |
---|
557 | "__cfaehm__try_resume_setup" ) ); |
---|
558 | setup->get_args().push_back( new AddressExpr( nameOf( obj ) ) ); |
---|
559 | setup->get_args().push_back( nameOf( resume_handler ) ); |
---|
560 | |
---|
561 | body->push_back( new ExprStmt( noLabels, setup ) ); |
---|
562 | |
---|
563 | body->push_back( wraps ); |
---|
564 | return body; |
---|
565 | } |
---|
566 | |
---|
567 | FunctionDecl * ExceptionMutatorCore::create_finally_wrapper( |
---|
568 | TryStmt * tryStmt ) { |
---|
569 | // void finally() { <finally code> } |
---|
570 | FinallyStmt * finally = tryStmt->get_finally(); |
---|
571 | CompoundStmt * body = finally->get_block(); |
---|
572 | finally->set_block( nullptr ); |
---|
573 | delete finally; |
---|
574 | tryStmt->set_finally( nullptr ); |
---|
575 | |
---|
576 | return new FunctionDecl("finally", Type::StorageClasses(), |
---|
577 | LinkageSpec::Cforall, finally_func_t.clone(), body); |
---|
578 | } |
---|
579 | |
---|
580 | ObjectDecl * ExceptionMutatorCore::create_finally_hook( |
---|
581 | FunctionDecl * finally_wrapper ) { |
---|
582 | // struct __cfaehm__cleanup_hook __finally_hook |
---|
583 | // __attribute__((cleanup( finally_wrapper ))); |
---|
584 | |
---|
585 | // Make Cleanup Attribute. |
---|
586 | std::list< Attribute * > attributes; |
---|
587 | { |
---|
588 | std::list< Expression * > attr_params; |
---|
589 | attr_params.push_back( nameOf( finally_wrapper ) ); |
---|
590 | attributes.push_back( new Attribute( "cleanup", attr_params ) ); |
---|
591 | } |
---|
592 | |
---|
593 | return new ObjectDecl( |
---|
594 | "__finally_hook", |
---|
595 | Type::StorageClasses(), |
---|
596 | LinkageSpec::Cforall, |
---|
597 | nullptr, |
---|
598 | new StructInstType( |
---|
599 | noQualifiers, |
---|
600 | hook_decl |
---|
601 | ), |
---|
602 | nullptr, |
---|
603 | attributes |
---|
604 | ); |
---|
605 | } |
---|
606 | |
---|
607 | // Visiting/Mutating Functions |
---|
608 | void ExceptionMutatorCore::premutate( CatchStmt *catchStmt ) { |
---|
609 | // Currently, we make up the declaration, as there isn't one for |
---|
610 | // integers. |
---|
611 | assert( ! catchStmt->get_decl() ); |
---|
612 | ObjectDecl * tmp = new ObjectDecl( |
---|
613 | "_hidden_local", |
---|
614 | Type::StorageClasses(), |
---|
615 | LinkageSpec::Cforall, |
---|
616 | nullptr, |
---|
617 | new PointerType( |
---|
618 | noQualifiers, |
---|
619 | new BasicType( noQualifiers, BasicType::SignedInt ) |
---|
620 | ), |
---|
621 | nullptr |
---|
622 | ); |
---|
623 | catchStmt->set_decl( tmp ); |
---|
624 | |
---|
625 | // Validate the Statement's form. |
---|
626 | ObjectDecl * decl = |
---|
627 | dynamic_cast<ObjectDecl *>( catchStmt->get_decl() ); |
---|
628 | if ( decl && true /* check decl->get_type() */ ) { |
---|
629 | // Pass. |
---|
630 | } else if ( CatchStmt::Terminate == catchStmt->get_kind() ) { |
---|
631 | throw SemanticError("catch must have exception type"); |
---|
632 | } else { |
---|
633 | throw SemanticError("catchResume must have exception type"); |
---|
634 | } |
---|
635 | |
---|
636 | // Track the handler context. |
---|
637 | GuardValue( cur_context ); |
---|
638 | if ( CatchStmt::Terminate == catchStmt->get_kind() ) { |
---|
639 | cur_context = TerHandler; |
---|
640 | |
---|
641 | GuardValue( handler_except_decl ); |
---|
642 | handler_except_decl = decl; |
---|
643 | } else { |
---|
644 | cur_context = ResHandler; |
---|
645 | } |
---|
646 | } |
---|
647 | |
---|
648 | void ExceptionMutatorCore::premutate( StructDecl *structDecl ) { |
---|
649 | if ( !structDecl->has_body() ) { |
---|
650 | // Skip children? |
---|
651 | return; |
---|
652 | } else if ( structDecl->get_name() == "__cfaehm__try_resume_node" ) { |
---|
653 | assert( nullptr == node_decl ); |
---|
654 | node_decl = structDecl; |
---|
655 | } else if ( structDecl->get_name() == "__cfaehm__cleanup_hook" ) { |
---|
656 | assert( nullptr == hook_decl ); |
---|
657 | hook_decl = structDecl; |
---|
658 | } |
---|
659 | // Later we might get the exception type as well. |
---|
660 | } |
---|
661 | |
---|
662 | Statement * ExceptionMutatorCore::postmutate( ThrowStmt *throwStmt ) { |
---|
663 | // Ignoring throwStmt->get_target() for now. |
---|
664 | if ( ThrowStmt::Terminate == throwStmt->get_kind() ) { |
---|
665 | if ( throwStmt->get_expr() ) { |
---|
666 | return create_terminate_throw( throwStmt ); |
---|
667 | } else if ( TerHandler == cur_context ) { |
---|
668 | return create_terminate_rethrow( throwStmt ); |
---|
669 | } else { |
---|
670 | assertf(false, "Invalid throw in %s at %i\n", |
---|
671 | throwStmt->location.filename.c_str(), |
---|
672 | throwStmt->location.linenumber); |
---|
673 | return nullptr; |
---|
674 | } |
---|
675 | } else { |
---|
676 | if ( throwStmt->get_expr() ) { |
---|
677 | return create_resume_throw( throwStmt ); |
---|
678 | } else if ( ResHandler == cur_context ) { |
---|
679 | return create_resume_rethrow( throwStmt ); |
---|
680 | } else { |
---|
681 | assertf(false, "Invalid throwResume in %s at %i\n", |
---|
682 | throwStmt->location.filename.c_str(), |
---|
683 | throwStmt->location.linenumber); |
---|
684 | return nullptr; |
---|
685 | } |
---|
686 | } |
---|
687 | } |
---|
688 | |
---|
689 | Statement * ExceptionMutatorCore::postmutate( TryStmt *tryStmt ) { |
---|
690 | assert( node_decl ); |
---|
691 | assert( hook_decl ); |
---|
692 | |
---|
693 | // Generate a prefix for the function names? |
---|
694 | |
---|
695 | CompoundStmt * block = new CompoundStmt( noLabels ); |
---|
696 | CompoundStmt * inner = take_try_block( tryStmt ); |
---|
697 | |
---|
698 | if ( tryStmt->get_finally() ) { |
---|
699 | // Define the helper function. |
---|
700 | FunctionDecl * finally_block = |
---|
701 | create_finally_wrapper( tryStmt ); |
---|
702 | appendDeclStmt( block, finally_block ); |
---|
703 | // Create and add the finally cleanup hook. |
---|
704 | appendDeclStmt( block, create_finally_hook( finally_block ) ); |
---|
705 | } |
---|
706 | |
---|
707 | CatchList termination_handlers; |
---|
708 | CatchList resumption_handlers; |
---|
709 | split( tryStmt->get_catchers(), |
---|
710 | termination_handlers, resumption_handlers ); |
---|
711 | |
---|
712 | if ( resumption_handlers.size() ) { |
---|
713 | // Define the helper function. |
---|
714 | FunctionDecl * resume_handler = |
---|
715 | create_resume_handler( resumption_handlers ); |
---|
716 | appendDeclStmt( block, resume_handler ); |
---|
717 | // Prepare hooks |
---|
718 | inner = create_resume_wrapper( inner, resume_handler ); |
---|
719 | } |
---|
720 | |
---|
721 | if ( termination_handlers.size() ) { |
---|
722 | // Define the three helper functions. |
---|
723 | FunctionDecl * try_wrapper = create_try_wrapper( inner ); |
---|
724 | appendDeclStmt( block, try_wrapper ); |
---|
725 | FunctionDecl * terminate_catch = |
---|
726 | create_terminate_catch( termination_handlers ); |
---|
727 | appendDeclStmt( block, terminate_catch ); |
---|
728 | FunctionDecl * terminate_match = |
---|
729 | create_terminate_match( termination_handlers ); |
---|
730 | appendDeclStmt( block, terminate_match ); |
---|
731 | // Build the call to the try wrapper. |
---|
732 | inner = create_terminate_caller( |
---|
733 | try_wrapper, terminate_catch, terminate_match ); |
---|
734 | } |
---|
735 | |
---|
736 | // Embed the try block. |
---|
737 | block->push_back( inner ); |
---|
738 | |
---|
739 | return block; |
---|
740 | } |
---|
741 | |
---|
742 | void translateEHM( std::list< Declaration *> & translationUnit ) { |
---|
743 | PassVisitor<ExceptionMutatorCore> translator; |
---|
744 | mutateAll( translationUnit, translator ); |
---|
745 | } |
---|
746 | } |
---|