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 | // FixInit.cc -- |
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8 | // |
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9 | // Author : Rob Schluntz |
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10 | // Created On : Wed Jan 13 16:29:30 2016 |
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11 | // Last Modified By : Peter A. Buhr |
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12 | // Last Modified On : Sun Feb 16 04:17:07 2020 |
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13 | // Update Count : 82 |
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14 | // |
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15 | #include "FixInit.h" |
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16 | |
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17 | #include <stddef.h> // for NULL |
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18 | #include <algorithm> // for set_difference, copy_if |
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19 | #include <cassert> // for assert, strict_dynamic_cast |
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20 | #include <iostream> // for operator<<, ostream, basic_ost... |
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21 | #include <iterator> // for insert_iterator, back_inserter |
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22 | #include <list> // for _List_iterator, list, list<>::... |
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23 | #include <map> // for _Rb_tree_iterator, _Rb_tree_co... |
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24 | #include <memory> // for allocator_traits<>::value_type |
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25 | #include <set> // for set, set<>::value_type |
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26 | #include <unordered_map> // for unordered_map, unordered_map<>... |
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27 | #include <unordered_set> // for unordered_set |
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28 | #include <utility> // for pair |
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29 | |
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30 | #include "CodeGen/GenType.h" // for genPrettyType |
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31 | #include "CodeGen/OperatorTable.h" |
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32 | #include "Common/PassVisitor.h" // for PassVisitor, WithStmtsToAdd |
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33 | #include "Common/SemanticError.h" // for SemanticError |
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34 | #include "Common/UniqueName.h" // for UniqueName |
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35 | #include "Common/utility.h" // for CodeLocation, ValueGuard, toSt... |
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36 | #include "FixGlobalInit.h" // for fixGlobalInit |
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37 | #include "GenInit.h" // for genCtorDtor |
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38 | #include "GenPoly/GenPoly.h" // for getFunctionType |
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39 | #include "InitTweak.h" // for getFunctionName, getCallArg |
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40 | #include "ResolvExpr/Resolver.h" // for findVoidExpression |
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41 | #include "ResolvExpr/typeops.h" // for typesCompatible |
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42 | #include "SymTab/Autogen.h" // for genImplicitCall |
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43 | #include "SymTab/Indexer.h" // for Indexer |
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44 | #include "SymTab/Mangler.h" // for Mangler |
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45 | #include "SynTree/LinkageSpec.h" // for C, Spec, Cforall, isBuiltin |
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46 | #include "SynTree/Attribute.h" // for Attribute |
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47 | #include "SynTree/Constant.h" // for Constant |
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48 | #include "SynTree/Declaration.h" // for ObjectDecl, FunctionDecl, Decl... |
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49 | #include "SynTree/Expression.h" // for UniqueExpr, VariableExpr, Unty... |
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50 | #include "SynTree/Initializer.h" // for ConstructorInit, SingleInit |
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51 | #include "SynTree/Label.h" // for Label, operator< |
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52 | #include "SynTree/Mutator.h" // for mutateAll, Mutator, maybeMutate |
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53 | #include "SynTree/Statement.h" // for ExprStmt, CompoundStmt, Branch... |
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54 | #include "SynTree/Type.h" // for Type, Type::StorageClasses |
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55 | #include "SynTree/TypeSubstitution.h" // for TypeSubstitution, operator<< |
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56 | #include "SynTree/DeclReplacer.h" // for DeclReplacer |
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57 | #include "SynTree/Visitor.h" // for acceptAll, maybeAccept |
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58 | #include "Validate/FindSpecialDecls.h" // for dtorStmt, dtorStructDestroy |
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59 | |
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60 | #include "AST/Expr.hpp" |
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61 | #include "AST/Node.hpp" |
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62 | #include "AST/Pass.hpp" |
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63 | #include "AST/Print.hpp" |
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64 | #include "AST/SymbolTable.hpp" |
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65 | #include "AST/Type.hpp" |
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66 | #include "AST/DeclReplacer.hpp" |
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67 | |
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68 | extern bool ctordtorp; // print all debug |
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69 | extern bool ctorp; // print ctor debug |
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70 | extern bool cpctorp; // print copy ctor debug |
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71 | extern bool dtorp; // print dtor debug |
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72 | #define PRINT( text ) if ( ctordtorp ) { text } |
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73 | #define CP_CTOR_PRINT( text ) if ( ctordtorp || cpctorp ) { text } |
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74 | #define DTOR_PRINT( text ) if ( ctordtorp || dtorp ) { text } |
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75 | |
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76 | namespace InitTweak { |
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77 | namespace { |
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78 | struct SelfAssignChecker { |
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79 | void previsit( const ast::ApplicationExpr * appExpr ); |
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80 | }; |
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81 | |
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82 | struct StmtExprResult { |
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83 | static void link( std::list<ast::ptr<ast::Decl> > & translationUnit ); |
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84 | |
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85 | const ast::StmtExpr * previsit( const ast::StmtExpr * stmtExpr ); |
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86 | }; |
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87 | |
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88 | struct InsertImplicitCalls : public ast::WithConstTypeSubstitution, public ast::WithShortCircuiting { |
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89 | /// wrap function application expressions as ImplicitCopyCtorExpr nodes so that it is easy to identify which |
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90 | /// function calls need their parameters to be copy constructed |
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91 | static void insert( std::list<ast::ptr<ast::Decl> > & translationUnit ); |
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92 | |
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93 | const ast::Expr * postvisit( const ast::ApplicationExpr * appExpr ); |
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94 | |
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95 | // only handles each UniqueExpr once |
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96 | // if order of visit does not change, this should be safe |
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97 | void previsit (const ast::UniqueExpr *); |
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98 | |
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99 | std::unordered_set<decltype(ast::UniqueExpr::id)> visitedIds; |
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100 | }; |
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101 | |
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102 | struct ResolveCopyCtors final : public ast::WithGuards, public ast::WithStmtsToAdd<>, public ast::WithSymbolTable, public ast::WithShortCircuiting, public ast::WithVisitorRef<ResolveCopyCtors> { |
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103 | /// generate temporary ObjectDecls for each argument and return value of each ImplicitCopyCtorExpr, |
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104 | /// generate/resolve copy construction expressions for each, and generate/resolve destructors for both |
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105 | /// arguments and return value temporaries |
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106 | static void resolveImplicitCalls( std::list<ast::ptr<ast::Decl> > & translationUnit ); |
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107 | |
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108 | const ast::Expr * postvisit( const ast::ImplicitCopyCtorExpr * impCpCtorExpr ); |
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109 | const ast::StmtExpr * previsit( const ast::StmtExpr * stmtExpr ); |
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110 | const ast::UniqueExpr * previsit( const ast::UniqueExpr * unqExpr ); |
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111 | |
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112 | /// handles distant mutations of environment manually. |
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113 | /// WithConstTypeSubstitution cannot remember where the environment is from |
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114 | |
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115 | /// MUST be called at start of overload previsit |
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116 | void previsit( const ast::Expr * expr); |
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117 | /// MUST be called at return of overload postvisit |
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118 | const ast::Expr * postvisit(const ast::Expr * expr); |
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119 | |
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120 | /// create and resolve ctor/dtor expression: fname(var, [cpArg]) |
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121 | const ast::Expr * makeCtorDtor( const std::string & fname, const ast::ObjectDecl * var, const ast::Expr * cpArg = nullptr ); |
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122 | /// true if type does not need to be copy constructed to ensure correctness |
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123 | bool skipCopyConstruct( const ast::Type * type ); |
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124 | ast::ptr< ast::Expr > copyConstructArg( const ast::Expr * arg, const ast::ImplicitCopyCtorExpr * impCpCtorExpr, const ast::Type * formal ); |
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125 | ast::Expr * destructRet( const ast::ObjectDecl * ret, const ast::Expr * arg ); |
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126 | private: |
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127 | /// hack to implement WithTypeSubstitution while conforming to mutation safety. |
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128 | ast::TypeSubstitution * env; |
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129 | bool envModified; |
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130 | }; |
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131 | |
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132 | /// collects constructed object decls - used as a base class |
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133 | struct ObjDeclCollector : public ast::WithGuards, public ast::WithShortCircuiting { |
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134 | // use ordered data structure to maintain ordering for set_difference and for consistent error messages |
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135 | typedef std::list< const ast::ObjectDecl * > ObjectSet; |
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136 | void previsit( const ast::CompoundStmt *compoundStmt ); |
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137 | void previsit( const ast::DeclStmt *stmt ); |
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138 | |
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139 | // don't go into other functions |
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140 | void previsit( const ast::FunctionDecl * ) { visit_children = false; } |
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141 | |
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142 | protected: |
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143 | ObjectSet curVars; |
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144 | }; |
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145 | |
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146 | // debug |
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147 | template<typename ObjectSet> |
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148 | struct PrintSet { |
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149 | PrintSet( const ObjectSet & objs ) : objs( objs ) {} |
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150 | const ObjectSet & objs; |
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151 | }; |
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152 | template<typename ObjectSet> |
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153 | PrintSet<ObjectSet> printSet( const ObjectSet & objs ) { return PrintSet<ObjectSet>( objs ); } |
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154 | template<typename ObjectSet> |
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155 | std::ostream & operator<<( std::ostream & out, const PrintSet<ObjectSet> & set) { |
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156 | out << "{ "; |
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157 | for ( auto & obj : set.objs ) { |
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158 | out << obj->name << ", " ; |
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159 | } // for |
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160 | out << " }"; |
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161 | return out; |
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162 | } |
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163 | |
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164 | struct LabelFinder final : public ObjDeclCollector { |
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165 | typedef std::map< std::string, ObjectSet > LabelMap; |
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166 | // map of Label -> live variables at that label |
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167 | LabelMap vars; |
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168 | |
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169 | typedef ObjDeclCollector Parent; |
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170 | using Parent::previsit; |
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171 | void previsit( const ast::Stmt * stmt ); |
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172 | |
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173 | void previsit( const ast::CompoundStmt *compoundStmt ); |
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174 | void previsit( const ast::DeclStmt *stmt ); |
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175 | }; |
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176 | |
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177 | struct InsertDtors final : public ObjDeclCollector, public ast::WithStmtsToAdd<> { |
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178 | /// insert destructor calls at the appropriate places. must happen before CtorInit nodes are removed |
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179 | /// (currently by FixInit) |
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180 | static void insert( std::list< ast::ptr<ast::Decl> > & translationUnit ); |
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181 | |
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182 | typedef std::list< ObjectDecl * > OrderedDecls; |
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183 | typedef std::list< OrderedDecls > OrderedDeclsStack; |
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184 | |
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185 | InsertDtors( ast::Pass<LabelFinder> & finder ) : finder( finder ), labelVars( finder.core.vars ) {} |
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186 | |
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187 | typedef ObjDeclCollector Parent; |
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188 | using Parent::previsit; |
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189 | |
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190 | void previsit( const ast::FunctionDecl * funcDecl ); |
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191 | |
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192 | void previsit( const ast::BranchStmt * stmt ); |
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193 | private: |
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194 | void handleGoto( const ast::BranchStmt * stmt ); |
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195 | |
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196 | ast::Pass<LabelFinder> & finder; |
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197 | LabelFinder::LabelMap & labelVars; |
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198 | OrderedDeclsStack reverseDeclOrder; |
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199 | }; |
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200 | |
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201 | class FixInit : public ast::WithStmtsToAdd<> { |
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202 | public: |
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203 | /// expand each object declaration to use its constructor after it is declared. |
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204 | static void fixInitializers( std::list< ast::ptr<ast::Decl> > &translationUnit ); |
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205 | |
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206 | const ast::DeclWithType * postvisit( const ast::ObjectDecl *objDecl ); |
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207 | |
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208 | std::list< ast::ptr< ast::Decl > > staticDtorDecls; |
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209 | }; |
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210 | |
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211 | struct GenStructMemberCalls final : public ast::WithGuards, public ast::WithShortCircuiting, public ast::WithSymbolTable, public ast::WithVisitorRef<GenStructMemberCalls> { |
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212 | /// generate default/copy ctor and dtor calls for user-defined struct ctor/dtors |
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213 | /// for any member that is missing a corresponding ctor/dtor call. |
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214 | /// error if a member is used before constructed |
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215 | static void generate( std::list< ast::ptr<ast::Decl> > & translationUnit ); |
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216 | |
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217 | void previsit( const ast::FunctionDecl * funcDecl ); |
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218 | const ast::DeclWithType * postvisit( const ast::FunctionDecl * funcDecl ); |
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219 | |
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220 | void previsit( const ast::MemberExpr * memberExpr ); |
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221 | void previsit( const ast::ApplicationExpr * appExpr ); |
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222 | |
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223 | /// Note: this post mutate used to be in a separate visitor. If this pass breaks, one place to examine is whether it is |
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224 | /// okay for this part of the recursion to occur alongside the rest. |
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225 | const ast::Expr * postvisit( const ast::UntypedExpr * expr ); |
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226 | |
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227 | SemanticErrorException errors; |
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228 | private: |
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229 | template< typename... Params > |
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230 | void emit( CodeLocation, const Params &... params ); |
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231 | |
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232 | ast::FunctionDecl * function = nullptr; |
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233 | std::set< const ast::DeclWithType * > unhandled; |
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234 | std::map< const ast::DeclWithType *, CodeLocation > usedUninit; |
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235 | const ast::ObjectDecl * thisParam = nullptr; |
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236 | bool isCtor = false; // true if current function is a constructor |
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237 | const ast::StructDecl * structDecl = nullptr; |
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238 | }; |
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239 | |
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240 | struct FixCtorExprs final : public ast::WithDeclsToAdd<>, public ast::WithSymbolTable, public ast::WithShortCircuiting { |
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241 | /// expands ConstructorExpr nodes into comma expressions, using a temporary for the first argument |
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242 | static void fix( std::list< ast::ptr<ast::Decl> > & translationUnit ); |
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243 | |
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244 | const ast::Expr * postvisit( const ast::ConstructorExpr * ctorExpr ); |
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245 | }; |
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246 | |
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247 | struct SplitExpressions : public ast::WithShortCircuiting { |
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248 | /// add CompoundStmts around top-level expressions so that temporaries are destroyed in the correct places. |
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249 | static void split( std::list<ast::ptr<ast::Decl> > & translationUnit ); |
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250 | |
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251 | ast::Stmt * postvisit( const ast::ExprStmt * stmt ); |
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252 | void previsit( const ast::TupleAssignExpr * expr ); |
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253 | }; |
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254 | } // namespace |
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255 | |
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256 | void fix( std::list< ast::ptr<ast::Decl> > & translationUnit, bool inLibrary ) { |
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257 | ast::Pass<SelfAssignChecker> checker; |
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258 | accept_all( translationUnit, checker ); |
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259 | |
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260 | // fixes StmtExpr to properly link to their resulting expression |
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261 | StmtExprResult::link( translationUnit ); |
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262 | |
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263 | // fixes ConstructorInit for global variables. should happen before fixInitializers. |
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264 | InitTweak::fixGlobalInit( translationUnit, inLibrary ); |
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265 | |
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266 | // must happen before ResolveCopyCtors because temporaries have to be inserted into the correct scope |
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267 | SplitExpressions::split( translationUnit ); |
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268 | |
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269 | InsertImplicitCalls::insert( translationUnit ); |
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270 | |
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271 | // Needs to happen before ResolveCopyCtors, because argument/return temporaries should not be considered in |
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272 | // error checking branch statements |
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273 | InsertDtors::insert( translationUnit ); |
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274 | |
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275 | ResolveCopyCtors::resolveImplicitCalls( translationUnit ); |
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276 | FixInit::fixInitializers( translationUnit ); |
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277 | GenStructMemberCalls::generate( translationUnit ); |
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278 | |
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279 | // Needs to happen after GenStructMemberCalls, since otherwise member constructors exprs |
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280 | // don't have the correct form, and a member can be constructed more than once. |
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281 | FixCtorExprs::fix( translationUnit ); |
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282 | } |
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283 | |
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284 | namespace { |
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285 | /// find and return the destructor used in `input`. If `input` is not a simple destructor call, generate a thunk |
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286 | /// that wraps the destructor, insert it into `stmtsToAdd` and return the new function declaration |
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287 | const ast::DeclWithType * getDtorFunc( const ast::ObjectDecl * objDecl, const ast::Stmt * input, std::list< ast::ptr<ast::Stmt> > & stmtsToAdd ) { |
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288 | const CodeLocation loc = input->location; |
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289 | // unwrap implicit statement wrapper |
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290 | // Statement * dtor = input; |
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291 | assert( input ); |
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292 | // std::list< const ast::Expr * > matches; |
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293 | auto matches = collectCtorDtorCalls( input ); |
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294 | |
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295 | if ( dynamic_cast< const ast::ExprStmt * >( input ) ) { |
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296 | // only one destructor call in the expression |
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297 | if ( matches.size() == 1 ) { |
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298 | auto func = getFunction( matches.front() ); |
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299 | assertf( func, "getFunction failed to find function in %s", toString( matches.front() ).c_str() ); |
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300 | |
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301 | // cleanup argument must be a function, not an object (including function pointer) |
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302 | if ( auto dtorFunc = dynamic_cast< const ast::FunctionDecl * > ( func ) ) { |
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303 | if ( dtorFunc->type->forall.empty() ) { |
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304 | // simple case where the destructor is a monomorphic function call - can simply |
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305 | // use that function as the cleanup function. |
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306 | return func; |
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307 | } |
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308 | } |
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309 | } |
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310 | } |
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311 | |
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312 | // otherwise the cleanup is more complicated - need to build a single argument cleanup function that |
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313 | // wraps the more complicated code. |
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314 | static UniqueName dtorNamer( "__cleanup_dtor" ); |
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315 | std::string name = dtorNamer.newName(); |
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316 | ast::FunctionDecl * dtorFunc = SymTab::genDefaultFunc( loc, name, objDecl->type->stripReferences(), false ); |
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317 | stmtsToAdd.push_back( new ast::DeclStmt(loc, dtorFunc ) ); |
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318 | |
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319 | // the original code contains uses of objDecl - replace them with the newly generated 'this' parameter. |
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320 | const ast::ObjectDecl * thisParam = getParamThis( dtorFunc ); |
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321 | const ast::Expr * replacement = new ast::VariableExpr( loc, thisParam ); |
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322 | |
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323 | auto base = replacement->result->stripReferences(); |
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324 | if ( dynamic_cast< const ast::ArrayType * >( base ) || dynamic_cast< const ast::TupleType * > ( base ) ) { |
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325 | // need to cast away reference for array types, since the destructor is generated without the reference type, |
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326 | // and for tuple types since tuple indexing does not work directly on a reference |
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327 | replacement = new ast::CastExpr( replacement, base ); |
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328 | } |
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329 | auto dtor = ast::DeclReplacer::replace( input, ast::DeclReplacer::ExprMap{ std::make_pair( objDecl, replacement ) } ); |
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330 | auto mutStmts = dtorFunc->stmts.get_and_mutate(); |
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331 | mutStmts->push_back(strict_dynamic_cast<const ast::Stmt *>( dtor )); |
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332 | dtorFunc->stmts = mutStmts; |
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333 | |
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334 | return dtorFunc; |
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335 | } |
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336 | |
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337 | void StmtExprResult::link( std::list<ast::ptr<ast::Decl> > & translationUnit ) { |
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338 | ast::Pass<StmtExprResult> linker; |
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339 | accept_all( translationUnit, linker ); |
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340 | } |
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341 | |
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342 | void SplitExpressions::split( std::list<ast::ptr<ast::Decl> > & translationUnit ) { |
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343 | ast::Pass<SplitExpressions> splitter; |
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344 | accept_all( translationUnit, splitter ); |
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345 | } |
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346 | |
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347 | void InsertImplicitCalls::insert( std::list<ast::ptr<ast::Decl> > & translationUnit ) { |
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348 | ast::Pass<InsertImplicitCalls> inserter; |
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349 | accept_all( translationUnit, inserter ); |
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350 | } |
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351 | |
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352 | void ResolveCopyCtors::resolveImplicitCalls( std::list< ast::ptr<ast::Decl> > & translationUnit ) { |
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353 | ast::Pass<ResolveCopyCtors> resolver; |
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354 | accept_all( translationUnit, resolver ); |
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355 | } |
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356 | |
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357 | void FixInit::fixInitializers( std::list< ast::ptr<ast::Decl> > & translationUnit ) { |
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358 | ast::Pass<FixInit> fixer; |
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359 | |
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360 | // can't use mutateAll, because need to insert declarations at top-level |
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361 | // can't use DeclMutator, because sometimes need to insert IfStmt, etc. |
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362 | SemanticErrorException errors; |
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363 | for ( auto i = translationUnit.begin(); i != translationUnit.end(); ++i ) { |
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364 | try { |
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365 | // maybeAccept( *i, fixer ); translationUnit should never contain null |
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366 | *i = (*i)->accept(fixer); |
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367 | translationUnit.splice( i, fixer.core.staticDtorDecls ); |
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368 | } catch( SemanticErrorException &e ) { |
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369 | errors.append( e ); |
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370 | } // try |
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371 | } // for |
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372 | if ( ! errors.isEmpty() ) { |
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373 | throw errors; |
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374 | } // if |
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375 | } |
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376 | |
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377 | void InsertDtors::insert( std::list< ast::ptr<ast::Decl> > & translationUnit ) { |
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378 | ast::Pass<LabelFinder> finder; |
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379 | ast::Pass<InsertDtors> inserter( finder ); |
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380 | accept_all( translationUnit, inserter ); |
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381 | } |
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382 | |
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383 | void GenStructMemberCalls::generate( std::list< ast::ptr<ast::Decl> > & translationUnit ) { |
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384 | ast::Pass<GenStructMemberCalls> warner; |
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385 | accept_all( translationUnit, warner ); |
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386 | } |
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387 | |
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388 | void FixCtorExprs::fix( std::list< ast::ptr<ast::Decl> > & translationUnit ) { |
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389 | ast::Pass<FixCtorExprs> fixer; |
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390 | accept_all( translationUnit, fixer ); |
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391 | } |
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392 | |
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393 | const ast::StmtExpr * StmtExprResult::previsit( const ast::StmtExpr * stmtExpr ) { |
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394 | // we might loose the result expression here so add a pointer to trace back |
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395 | assert( stmtExpr->result ); |
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396 | const ast::Type * result = stmtExpr->result; |
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397 | if ( ! result->isVoid() ) { |
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398 | auto mutExpr = mutate(stmtExpr); |
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399 | const ast::CompoundStmt * body = mutExpr->stmts; |
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400 | assert( ! body->kids.empty() ); |
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401 | mutExpr->resultExpr = body->kids.back().strict_as<ast::ExprStmt>(); |
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402 | return mutExpr; |
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403 | } |
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404 | return stmtExpr; |
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405 | } |
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406 | |
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407 | ast::Stmt * SplitExpressions::postvisit( const ast::ExprStmt * stmt ) { |
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408 | // wrap each top-level ExprStmt in a block so that destructors for argument and return temporaries are destroyed |
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409 | // in the correct places |
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410 | ast::CompoundStmt * ret = new ast::CompoundStmt( stmt->location, { stmt } ); |
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411 | return ret; |
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412 | } |
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413 | |
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414 | void SplitExpressions::previsit( const ast::TupleAssignExpr * ) { |
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415 | // don't do this within TupleAssignExpr, since it is already broken up into multiple expressions |
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416 | visit_children = false; |
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417 | } |
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418 | |
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419 | // Relatively simple structural comparison for expressions, needed to determine |
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420 | // if two expressions are "the same" (used to determine if self assignment occurs) |
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421 | struct StructuralChecker { |
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422 | const ast::Expr * stripCasts( const ast::Expr * expr ) { |
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423 | // this might be too permissive. It's possible that only particular casts are relevant. |
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424 | while ( auto cast = dynamic_cast< const ast::CastExpr * >( expr ) ) { |
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425 | expr = cast->arg; |
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426 | } |
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427 | return expr; |
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428 | } |
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429 | |
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430 | void previsit( const ast::Expr * ) { |
---|
431 | // anything else does not qualify |
---|
432 | isSimilar = false; |
---|
433 | } |
---|
434 | |
---|
435 | template<typename T> |
---|
436 | T * cast( const ast::Expr * node ) { |
---|
437 | // all expressions need to ignore casts, so this bit has been factored out |
---|
438 | return dynamic_cast< T * >( stripCasts( node ) ); |
---|
439 | } |
---|
440 | |
---|
441 | // ignore casts |
---|
442 | void previsit( const ast::CastExpr * ) {} |
---|
443 | |
---|
444 | void previsit( const ast::MemberExpr * memExpr ) { |
---|
445 | if ( auto otherMember = cast< const ast::MemberExpr >( other ) ) { |
---|
446 | if ( otherMember->member == memExpr->member ) { |
---|
447 | other = otherMember->aggregate; |
---|
448 | return; |
---|
449 | } |
---|
450 | } |
---|
451 | isSimilar = false; |
---|
452 | } |
---|
453 | |
---|
454 | void previsit( const ast::VariableExpr * varExpr ) { |
---|
455 | if ( auto otherVar = cast< const ast::VariableExpr >( other ) ) { |
---|
456 | if ( otherVar->var == varExpr->var ) { |
---|
457 | return; |
---|
458 | } |
---|
459 | } |
---|
460 | isSimilar = false; |
---|
461 | } |
---|
462 | |
---|
463 | void previsit( const ast::AddressExpr * ) { |
---|
464 | if ( auto addrExpr = cast< const ast::AddressExpr >( other ) ) { |
---|
465 | other = addrExpr->arg; |
---|
466 | return; |
---|
467 | } |
---|
468 | isSimilar = false; |
---|
469 | } |
---|
470 | |
---|
471 | const ast::Expr * other = nullptr; |
---|
472 | bool isSimilar = true; |
---|
473 | }; |
---|
474 | |
---|
475 | bool structurallySimilar( const ast::Expr * e1, const ast::Expr * e2 ) { |
---|
476 | ast::Pass<StructuralChecker> checker; |
---|
477 | checker.core.other = e2; |
---|
478 | e1->accept( checker ); |
---|
479 | return checker.core.isSimilar; |
---|
480 | } |
---|
481 | |
---|
482 | void SelfAssignChecker::previsit( const ast::ApplicationExpr * appExpr ) { |
---|
483 | auto function = getFunction( appExpr ); |
---|
484 | if ( function->name == "?=?" ) { // doesn't use isAssignment, because ?+=?, etc. should not count as self-assignment |
---|
485 | if ( appExpr->args.size() == 2 ) { |
---|
486 | // check for structural similarity (same variable use, ignore casts, etc. - but does not look too deeply, anything looking like a function is off limits) |
---|
487 | if ( structurallySimilar( appExpr->args.front(), appExpr->args.back() ) ) { |
---|
488 | SemanticWarning( appExpr->location, Warning::SelfAssignment, toCString( appExpr->args.front() ) ); |
---|
489 | } |
---|
490 | } |
---|
491 | } |
---|
492 | } |
---|
493 | |
---|
494 | const ast::Expr * InsertImplicitCalls::postvisit( const ast::ApplicationExpr * appExpr ) { |
---|
495 | if ( auto function = appExpr->func.as<ast::VariableExpr>() ) { |
---|
496 | if ( function->var->linkage.is_builtin ) { |
---|
497 | // optimization: don't need to copy construct in order to call intrinsic functions |
---|
498 | return appExpr; |
---|
499 | } else if ( auto funcDecl = function->var.as<ast::DeclWithType>() ) { |
---|
500 | auto ftype = dynamic_cast< const ast::FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) ); |
---|
501 | assertf( ftype, "Function call without function type: %s", toString( funcDecl ).c_str() ); |
---|
502 | if ( CodeGen::isConstructor( funcDecl->name ) && ftype->params.size() == 2 ) { |
---|
503 | auto t1 = getPointerBase( ftype->params.front() ); |
---|
504 | auto t2 = ftype->params.back(); |
---|
505 | assert( t1 ); |
---|
506 | |
---|
507 | if ( ResolvExpr::typesCompatible( t1, t2 ) ) { |
---|
508 | // optimization: don't need to copy construct in order to call a copy constructor |
---|
509 | return appExpr; |
---|
510 | } // if |
---|
511 | } else if ( CodeGen::isDestructor( funcDecl->name ) ) { |
---|
512 | // correctness: never copy construct arguments to a destructor |
---|
513 | return appExpr; |
---|
514 | } // if |
---|
515 | } // if |
---|
516 | } // if |
---|
517 | CP_CTOR_PRINT( std::cerr << "InsertImplicitCalls: adding a wrapper " << appExpr << std::endl; ) |
---|
518 | |
---|
519 | // wrap each function call so that it is easy to identify nodes that have to be copy constructed |
---|
520 | ast::ptr<ast::TypeSubstitution> tmp = appExpr->env; |
---|
521 | auto mutExpr = mutate(appExpr); |
---|
522 | mutExpr->env = nullptr; |
---|
523 | |
---|
524 | auto expr = new ast::ImplicitCopyCtorExpr( appExpr->location, mutExpr ); |
---|
525 | // Move the type substitution to the new top-level, if it is attached to the appExpr. |
---|
526 | // Ensure it is not deleted with the ImplicitCopyCtorExpr by removing it before deletion. |
---|
527 | // The substitution is needed to obtain the type of temporary variables so that copy constructor |
---|
528 | // calls can be resolved. |
---|
529 | assert( typeSubs ); |
---|
530 | // assert (mutExpr->env); |
---|
531 | expr->env = tmp; |
---|
532 | // mutExpr->env = nullptr; |
---|
533 | //std::swap( expr->env, appExpr->env ); |
---|
534 | return expr; |
---|
535 | } |
---|
536 | |
---|
537 | void ResolveCopyCtors::previsit(const ast::Expr * expr) { |
---|
538 | if (expr->env) { |
---|
539 | GuardValue(env); |
---|
540 | GuardValue(envModified); |
---|
541 | env = expr->env->clone(); |
---|
542 | envModified = false; |
---|
543 | } |
---|
544 | } |
---|
545 | |
---|
546 | const ast::Expr * ResolveCopyCtors::postvisit(const ast::Expr * expr) { |
---|
547 | if (expr->env) { |
---|
548 | if (envModified) { |
---|
549 | auto mutExpr = mutate(expr); |
---|
550 | mutExpr->env = env; |
---|
551 | return mutExpr; |
---|
552 | } |
---|
553 | else { |
---|
554 | // env was not mutated, skip and delete the shallow copy |
---|
555 | delete env; |
---|
556 | return expr; |
---|
557 | } |
---|
558 | } |
---|
559 | else { |
---|
560 | return expr; |
---|
561 | } |
---|
562 | } |
---|
563 | |
---|
564 | bool ResolveCopyCtors::skipCopyConstruct( const ast::Type * type ) { return ! isConstructable( type ); } |
---|
565 | |
---|
566 | const ast::Expr * ResolveCopyCtors::makeCtorDtor( const std::string & fname, const ast::ObjectDecl * var, const ast::Expr * cpArg ) { |
---|
567 | assert( var ); |
---|
568 | assert (var->isManaged()); |
---|
569 | assert (!cpArg || cpArg->isManaged()); |
---|
570 | // arrays are not copy constructed, so this should always be an ExprStmt |
---|
571 | ast::ptr< ast::Stmt > stmt = genCtorDtor(var->location, fname, var, cpArg ); |
---|
572 | assertf( stmt, "ResolveCopyCtors: genCtorDtor returned nullptr: %s / %s / %s", fname.c_str(), toString( var ).c_str(), toString( cpArg ).c_str() ); |
---|
573 | auto exprStmt = stmt.strict_as<ast::ImplicitCtorDtorStmt>()->callStmt.strict_as<ast::ExprStmt>(); |
---|
574 | ast::ptr<ast::Expr> untyped = exprStmt->expr; // take ownership of expr |
---|
575 | // exprStmt->expr = nullptr; |
---|
576 | |
---|
577 | // resolve copy constructor |
---|
578 | // should only be one alternative for copy ctor and dtor expressions, since all arguments are fixed |
---|
579 | // (VariableExpr and already resolved expression) |
---|
580 | CP_CTOR_PRINT( std::cerr << "ResolvingCtorDtor " << untyped << std::endl; ) |
---|
581 | ast::ptr<ast::Expr> resolved = ResolvExpr::findVoidExpression(untyped, symtab); |
---|
582 | assert( resolved ); |
---|
583 | if ( resolved->env ) { |
---|
584 | // Extract useful information and discard new environments. Keeping them causes problems in PolyMutator passes. |
---|
585 | env->add( *resolved->env ); |
---|
586 | envModified = true; |
---|
587 | // delete resolved->env; |
---|
588 | auto mut = mutate(resolved.get()); |
---|
589 | assertf(mut == resolved.get(), "newly resolved expression must be unique"); |
---|
590 | mut->env = nullptr; |
---|
591 | } // if |
---|
592 | // delete stmt; |
---|
593 | if ( auto assign = resolved.as<ast::TupleAssignExpr>() ) { |
---|
594 | // fix newly generated StmtExpr |
---|
595 | previsit( assign->stmtExpr ); |
---|
596 | } |
---|
597 | return resolved.release(); |
---|
598 | } |
---|
599 | |
---|
600 | ast::ptr<ast::Expr> ResolveCopyCtors::copyConstructArg( |
---|
601 | const ast::Expr * arg, const ast::ImplicitCopyCtorExpr * impCpCtorExpr, const ast::Type * formal ) |
---|
602 | { |
---|
603 | static UniqueName tempNamer("_tmp_cp"); |
---|
604 | assert( env ); |
---|
605 | const CodeLocation loc = impCpCtorExpr->location; |
---|
606 | // CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *env << std::endl; ) |
---|
607 | assert( arg->result ); |
---|
608 | ast::ptr<ast::Type> result = arg->result; |
---|
609 | if ( skipCopyConstruct( result ) ) return arg; // skip certain non-copyable types |
---|
610 | |
---|
611 | // type may involve type variables, so apply type substitution to get temporary variable's actual type, |
---|
612 | // since result type may not be substituted (e.g., if the type does not appear in the parameter list) |
---|
613 | // Use applyFree so that types bound in function pointers are not substituted, e.g. in forall(dtype T) void (*)(T). |
---|
614 | |
---|
615 | // xxx - this originally mutates arg->result in place. is it correct? |
---|
616 | result = env->applyFree( result.get() ).node; |
---|
617 | auto mutResult = result.get_and_mutate(); |
---|
618 | mutResult->set_const(false); |
---|
619 | |
---|
620 | auto mutArg = mutate(arg); |
---|
621 | mutArg->result = mutResult; |
---|
622 | |
---|
623 | ast::ptr<ast::Expr> guard = mutArg; |
---|
624 | |
---|
625 | ast::ptr<ast::ObjectDecl> tmp = new ast::ObjectDecl({}, "__tmp", mutResult, nullptr ); |
---|
626 | |
---|
627 | // create and resolve copy constructor |
---|
628 | CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; ) |
---|
629 | auto cpCtor = makeCtorDtor( "?{}", tmp, mutArg ); |
---|
630 | |
---|
631 | if ( auto appExpr = dynamic_cast< const ast::ApplicationExpr * >( cpCtor ) ) { |
---|
632 | // if the chosen constructor is intrinsic, the copy is unnecessary, so |
---|
633 | // don't create the temporary and don't call the copy constructor |
---|
634 | auto function = appExpr->func.strict_as<ast::VariableExpr>(); |
---|
635 | if ( function->var->linkage == ast::Linkage::Intrinsic ) { |
---|
636 | // arguments that need to be boxed need a temporary regardless of whether the copy constructor is intrinsic, |
---|
637 | // so that the object isn't changed inside of the polymorphic function |
---|
638 | if ( ! GenPoly::needsBoxing( formal, result, impCpCtorExpr->callExpr, env ) ) { |
---|
639 | // xxx - should arg->result be mutated? see comment above. |
---|
640 | return guard; |
---|
641 | } |
---|
642 | } |
---|
643 | } |
---|
644 | |
---|
645 | // set a unique name for the temporary once it's certain the call is necessary |
---|
646 | auto mut = tmp.get_and_mutate(); |
---|
647 | assertf (mut == tmp, "newly created ObjectDecl must be unique"); |
---|
648 | mut->name = tempNamer.newName(); |
---|
649 | |
---|
650 | // replace argument to function call with temporary |
---|
651 | stmtsToAddBefore.push_back( new ast::DeclStmt(loc, tmp ) ); |
---|
652 | arg = cpCtor; |
---|
653 | return destructRet( tmp, arg ); |
---|
654 | |
---|
655 | // impCpCtorExpr->dtors.push_front( makeCtorDtor( "^?{}", tmp ) ); |
---|
656 | } |
---|
657 | |
---|
658 | ast::Expr * ResolveCopyCtors::destructRet( const ast::ObjectDecl * ret, const ast::Expr * arg ) { |
---|
659 | // TODO: refactor code for generating cleanup attribute, since it's common and reused in ~3-4 places |
---|
660 | // check for existing cleanup attribute before adding another(?) |
---|
661 | // need to add __Destructor for _tmp_cp variables as well |
---|
662 | |
---|
663 | assertf( ast::dtorStruct && ast::dtorStruct->members.size() == 2, "Destructor generation requires __Destructor definition." ); |
---|
664 | assertf( ast::dtorStructDestroy, "Destructor generation requires __destroy_Destructor." ); |
---|
665 | |
---|
666 | const CodeLocation loc = ret->location; |
---|
667 | |
---|
668 | // generate a __Destructor for ret that calls the destructor |
---|
669 | auto res = makeCtorDtor( "^?{}", ret ); |
---|
670 | auto dtor = mutate(res); |
---|
671 | |
---|
672 | // if the chosen destructor is intrinsic, elide the generated dtor handler |
---|
673 | if ( arg && isIntrinsicCallExpr( dtor ) ) { |
---|
674 | return new ast::CommaExpr(loc, arg, new ast::VariableExpr(loc, ret ) ); |
---|
675 | // return; |
---|
676 | } |
---|
677 | |
---|
678 | if ( ! dtor->env ) dtor->env = maybeClone( env ); |
---|
679 | auto dtorFunc = getDtorFunc( ret, new ast::ExprStmt(loc, dtor ), stmtsToAddBefore ); |
---|
680 | |
---|
681 | auto dtorStructType = new ast::StructInstType(ast::dtorStruct); |
---|
682 | |
---|
683 | // what does this do??? |
---|
684 | dtorStructType->params.push_back( new ast::TypeExpr(loc, new ast::VoidType() ) ); |
---|
685 | |
---|
686 | // cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings |
---|
687 | auto dtorFtype = new ast::FunctionType(); |
---|
688 | dtorFtype->params.push_back( new ast::PointerType(new ast::VoidType( ) ) ); |
---|
689 | auto dtorType = new ast::PointerType( dtorFtype ); |
---|
690 | |
---|
691 | static UniqueName namer( "_ret_dtor" ); |
---|
692 | auto retDtor = new ast::ObjectDecl(loc, namer.newName(), dtorStructType, new ast::ListInit(loc, { new ast::SingleInit(loc, ast::ConstantExpr::null(loc) ), new ast::SingleInit(loc, new ast::CastExpr( new ast::VariableExpr(loc, dtorFunc ), dtorType ) ) } ) ); |
---|
693 | retDtor->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr(loc, ast::dtorStructDestroy ) } ) ); |
---|
694 | stmtsToAddBefore.push_back( new ast::DeclStmt(loc, retDtor ) ); |
---|
695 | |
---|
696 | if ( arg ) { |
---|
697 | auto member = new ast::MemberExpr(loc, ast::dtorStruct->members.front().strict_as<ast::DeclWithType>(), new ast::VariableExpr(loc, retDtor ) ); |
---|
698 | auto object = new ast::CastExpr( new ast::AddressExpr( new ast::VariableExpr(loc, ret ) ), new ast::PointerType(new ast::VoidType() ) ); |
---|
699 | ast::Expr * assign = createBitwiseAssignment( member, object ); |
---|
700 | return new ast::CommaExpr(loc, new ast::CommaExpr(loc, arg, assign ), new ast::VariableExpr(loc, ret ) ); |
---|
701 | } |
---|
702 | return nullptr; |
---|
703 | // impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) ); |
---|
704 | } |
---|
705 | |
---|
706 | const ast::Expr * ResolveCopyCtors::postvisit( const ast::ImplicitCopyCtorExpr *impCpCtorExpr ) { |
---|
707 | CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; ) |
---|
708 | |
---|
709 | ast::ApplicationExpr * appExpr = mutate(impCpCtorExpr->callExpr.get()); |
---|
710 | const ast::ObjectDecl * returnDecl = nullptr; |
---|
711 | const CodeLocation loc = appExpr->location; |
---|
712 | |
---|
713 | // take each argument and attempt to copy construct it. |
---|
714 | auto ftype = GenPoly::getFunctionType( appExpr->func->result ); |
---|
715 | assert( ftype ); |
---|
716 | auto & params = ftype->params; |
---|
717 | auto iter = params.begin(); |
---|
718 | for ( auto & arg : appExpr->args ) { |
---|
719 | const ast::Type * formal = nullptr; |
---|
720 | if ( iter != params.end() ) { // does not copy construct C-style variadic arguments |
---|
721 | // DeclarationWithType * param = *iter++; |
---|
722 | formal = *iter++; |
---|
723 | } |
---|
724 | |
---|
725 | arg = copyConstructArg( arg, impCpCtorExpr, formal ); |
---|
726 | } // for |
---|
727 | |
---|
728 | // each return value from the call needs to be connected with an ObjectDecl at the call site, which is |
---|
729 | // initialized with the return value and is destructed later |
---|
730 | // xxx - handle named return values? |
---|
731 | const ast::Type * result = appExpr->result; |
---|
732 | if ( ! result->isVoid() ) { |
---|
733 | static UniqueName retNamer("_tmp_cp_ret"); |
---|
734 | // result = result->clone(); |
---|
735 | auto subResult = env->apply( result ).node; |
---|
736 | auto ret = new ast::ObjectDecl(loc, retNamer.newName(), subResult, nullptr ); |
---|
737 | auto mutType = mutate(ret->type.get()); |
---|
738 | mutType->set_const( false ); |
---|
739 | ret->type = mutType; |
---|
740 | returnDecl = ret; |
---|
741 | stmtsToAddBefore.push_back( new ast::DeclStmt(loc, ret ) ); |
---|
742 | CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; ) |
---|
743 | } // for |
---|
744 | CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; ) |
---|
745 | // ------------------------------------------------------ |
---|
746 | |
---|
747 | CP_CTOR_PRINT( std::cerr << "Coming out the back..." << impCpCtorExpr << std::endl; ) |
---|
748 | |
---|
749 | // detach fields from wrapper node so that it can be deleted without deleting too much |
---|
750 | |
---|
751 | // xxx - actual env might be somewhere else, need to keep invariant |
---|
752 | |
---|
753 | // deletion of wrapper should be handled by pass template now |
---|
754 | |
---|
755 | // impCpCtorExpr->callExpr = nullptr; |
---|
756 | assert (appExpr->env == nullptr); |
---|
757 | appExpr->env = impCpCtorExpr->env; |
---|
758 | // std::swap( impCpCtorExpr->env, appExpr->env ); |
---|
759 | // assert( impCpCtorExpr->env == nullptr ); |
---|
760 | // delete impCpCtorExpr; |
---|
761 | |
---|
762 | if ( returnDecl ) { |
---|
763 | ast::Expr * assign = createBitwiseAssignment( new ast::VariableExpr(loc, returnDecl ), appExpr ); |
---|
764 | if ( ! dynamic_cast< const ast::ReferenceType * >( result ) ) { |
---|
765 | // destructing reference returns is bad because it can cause multiple destructor calls to the same object - the returned object is not a temporary |
---|
766 | assign = destructRet( returnDecl, assign ); |
---|
767 | assert(assign); |
---|
768 | } else { |
---|
769 | assign = new ast::CommaExpr(loc, assign, new ast::VariableExpr(loc, returnDecl ) ); |
---|
770 | } |
---|
771 | // move env from appExpr to retExpr |
---|
772 | // std::swap( assign->env, appExpr->env ); |
---|
773 | assign->env = appExpr->env; |
---|
774 | // actual env is handled by common routine that replaces WithTypeSubstitution |
---|
775 | return postvisit((const ast::Expr *)assign); |
---|
776 | } else { |
---|
777 | return postvisit((const ast::Expr *)appExpr); |
---|
778 | } // if |
---|
779 | } |
---|
780 | |
---|
781 | const ast::StmtExpr * ResolveCopyCtors::previsit( const ast::StmtExpr * _stmtExpr ) { |
---|
782 | // function call temporaries should be placed at statement-level, rather than nested inside of a new statement expression, |
---|
783 | // since temporaries can be shared across sub-expressions, e.g. |
---|
784 | // [A, A] f(); // decl |
---|
785 | // g([A] x, [A] y); // decl |
---|
786 | // g(f()); // call |
---|
787 | // f is executed once, so the return temporary is shared across the tuple constructors for x and y. |
---|
788 | // Explicitly mutating children instead of mutating the inner compound statement forces the temporaries to be added |
---|
789 | // to the outer context, rather than inside of the statement expression. |
---|
790 | |
---|
791 | // call the common routine that replaces WithTypeSubstitution |
---|
792 | previsit((const ast::Expr *) _stmtExpr); |
---|
793 | |
---|
794 | visit_children = false; |
---|
795 | const CodeLocation loc = _stmtExpr->location; |
---|
796 | |
---|
797 | assert( env ); |
---|
798 | |
---|
799 | symtab.enterScope(); |
---|
800 | // visit all statements |
---|
801 | auto stmtExpr = mutate(_stmtExpr); |
---|
802 | auto mutStmts = mutate(stmtExpr->stmts.get()); |
---|
803 | |
---|
804 | auto & stmts = mutStmts->kids; |
---|
805 | for ( auto & stmt : stmts ) { |
---|
806 | stmt = stmt->accept( *visitor ); |
---|
807 | } // for |
---|
808 | stmtExpr->stmts = mutStmts; |
---|
809 | symtab.leaveScope(); |
---|
810 | |
---|
811 | assert( stmtExpr->result ); |
---|
812 | // const ast::Type * result = stmtExpr->result; |
---|
813 | if ( ! stmtExpr->result->isVoid() ) { |
---|
814 | static UniqueName retNamer("_tmp_stmtexpr_ret"); |
---|
815 | |
---|
816 | // result = result->clone(); |
---|
817 | auto result = env->apply( stmtExpr->result.get() ).node; |
---|
818 | if ( ! InitTweak::isConstructable( result ) ) { |
---|
819 | // delete result; |
---|
820 | return stmtExpr; |
---|
821 | } |
---|
822 | auto mutResult = result.get_and_mutate(); |
---|
823 | mutResult->set_const(false); |
---|
824 | |
---|
825 | // create variable that will hold the result of the stmt expr |
---|
826 | auto ret = new ast::ObjectDecl(loc, retNamer.newName(), mutResult, nullptr ); |
---|
827 | stmtsToAddBefore.push_back( new ast::DeclStmt(loc, ret ) ); |
---|
828 | |
---|
829 | assertf( |
---|
830 | stmtExpr->resultExpr, |
---|
831 | "Statement-Expression should have a resulting expression at %s:%d", |
---|
832 | stmtExpr->location.filename.c_str(), |
---|
833 | stmtExpr->location.first_line |
---|
834 | ); |
---|
835 | |
---|
836 | const ast::ExprStmt * last = stmtExpr->resultExpr; |
---|
837 | // xxx - if this is non-unique, need to copy while making resultExpr ref |
---|
838 | assertf(last->unique(), "attempt to modify weakly shared statement"); |
---|
839 | auto mutLast = mutate(last); |
---|
840 | // above assertion means in-place mutation is OK |
---|
841 | try { |
---|
842 | mutLast->expr = makeCtorDtor( "?{}", ret, mutLast->expr ); |
---|
843 | } catch(...) { |
---|
844 | std::cerr << "*CFA internal error: "; |
---|
845 | std::cerr << "can't resolve implicit constructor"; |
---|
846 | std::cerr << " at " << stmtExpr->location.filename; |
---|
847 | std::cerr << ":" << stmtExpr->location.first_line << std::endl; |
---|
848 | |
---|
849 | abort(); |
---|
850 | } |
---|
851 | |
---|
852 | // add destructors after current statement |
---|
853 | stmtsToAddAfter.push_back( new ast::ExprStmt(loc, makeCtorDtor( "^?{}", ret ) ) ); |
---|
854 | |
---|
855 | // must have a non-empty body, otherwise it wouldn't have a result |
---|
856 | assert( ! stmts.empty() ); |
---|
857 | |
---|
858 | // if there is a return decl, add a use as the last statement; will not have return decl on non-constructable returns |
---|
859 | stmts.push_back( new ast::ExprStmt(loc, new ast::VariableExpr(loc, ret ) ) ); |
---|
860 | } // if |
---|
861 | |
---|
862 | assert( stmtExpr->returnDecls.empty() ); |
---|
863 | assert( stmtExpr->dtors.empty() ); |
---|
864 | |
---|
865 | return stmtExpr; |
---|
866 | } |
---|
867 | |
---|
868 | // to prevent warnings ('_unq0' may be used uninitialized in this function), |
---|
869 | // insert an appropriate zero initializer for UniqueExpr temporaries. |
---|
870 | ast::Init * makeInit( const ast::Type * t ) { |
---|
871 | if ( auto inst = dynamic_cast< const ast::StructInstType * >( t ) ) { |
---|
872 | // initizer for empty struct must be empty |
---|
873 | if ( inst->base->members.empty() ) return new ast::ListInit({}, {}); |
---|
874 | } else if ( auto inst = dynamic_cast< const ast::UnionInstType * >( t ) ) { |
---|
875 | // initizer for empty union must be empty |
---|
876 | if ( inst->base->members.empty() ) return new ast::ListInit({}, {}); |
---|
877 | } |
---|
878 | |
---|
879 | return new ast::ListInit( {}, { new ast::SingleInit( {}, ast::ConstantExpr::from_int({}, 0) ) } ); |
---|
880 | } |
---|
881 | |
---|
882 | const ast::UniqueExpr * ResolveCopyCtors::previsit( const ast::UniqueExpr * unqExpr ) { |
---|
883 | visit_children = false; |
---|
884 | // xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated |
---|
885 | static std::unordered_map< int, const ast::UniqueExpr * > unqMap; |
---|
886 | auto mutExpr = mutate(unqExpr); |
---|
887 | if ( ! unqMap.count( unqExpr->id ) ) { |
---|
888 | // resolve expr and find its |
---|
889 | |
---|
890 | auto impCpCtorExpr = mutExpr->expr.as<ast::ImplicitCopyCtorExpr>(); |
---|
891 | // PassVisitor<ResolveCopyCtors> fixer; |
---|
892 | |
---|
893 | mutExpr->expr = mutExpr->expr->accept( *visitor ); |
---|
894 | // it should never be necessary to wrap a void-returning expression in a UniqueExpr - if this assumption changes, this needs to be rethought |
---|
895 | assert( unqExpr->result ); |
---|
896 | if ( impCpCtorExpr ) { |
---|
897 | auto comma = unqExpr->expr.strict_as<ast::CommaExpr>(); |
---|
898 | auto var = comma->arg2.strict_as<ast::VariableExpr>(); |
---|
899 | // note the variable used as the result from the call |
---|
900 | mutExpr->var = var; |
---|
901 | } else { |
---|
902 | // expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression |
---|
903 | mutExpr->object = new ast::ObjectDecl( mutExpr->location, toString("_unq", mutExpr->id), mutExpr->result, makeInit( mutExpr->result ) ); |
---|
904 | mutExpr->var = new ast::VariableExpr( mutExpr->location, mutExpr->object ); |
---|
905 | } |
---|
906 | |
---|
907 | // stmtsToAddBefore.splice( stmtsToAddBefore.end(), fixer.pass.stmtsToAddBefore ); |
---|
908 | // stmtsToAddAfter.splice( stmtsToAddAfter.end(), fixer.pass.stmtsToAddAfter ); |
---|
909 | unqMap[mutExpr->id] = mutExpr; |
---|
910 | } else { |
---|
911 | // take data from other UniqueExpr to ensure consistency |
---|
912 | // delete unqExpr->get_expr(); |
---|
913 | mutExpr->expr = unqMap[mutExpr->id]->expr; |
---|
914 | // delete unqExpr->result; |
---|
915 | mutExpr->result = mutExpr->expr->result; |
---|
916 | } |
---|
917 | return mutExpr; |
---|
918 | } |
---|
919 | |
---|
920 | const ast::DeclWithType * FixInit::postvisit( const ast::ObjectDecl *_objDecl ) { |
---|
921 | const CodeLocation loc = _objDecl->location; |
---|
922 | |
---|
923 | // since this removes the init field from objDecl, it must occur after children are mutated (i.e. postvisit) |
---|
924 | if ( ast::ptr<ast::ConstructorInit> ctorInit = _objDecl->init.as<ast::ConstructorInit>() ) { |
---|
925 | auto objDecl = mutate(_objDecl); |
---|
926 | |
---|
927 | // could this be non-unique? |
---|
928 | if (objDecl != _objDecl) { |
---|
929 | std::cerr << "FixInit: non-unique object decl " << objDecl->location << objDecl->name << std::endl; |
---|
930 | } |
---|
931 | // a decision should have been made by the resolver, so ctor and init are not both non-NULL |
---|
932 | assert( ! ctorInit->ctor || ! ctorInit->init ); |
---|
933 | if ( const ast::Stmt * ctor = ctorInit->ctor ) { |
---|
934 | if ( objDecl->storage.is_static ) { |
---|
935 | // originally wanted to take advantage of gcc nested functions, but |
---|
936 | // we get memory errors with this approach. To remedy this, the static |
---|
937 | // variable is hoisted when the destructor needs to be called. |
---|
938 | // |
---|
939 | // generate: |
---|
940 | // static T __objName_static_varN; |
---|
941 | // void __objName_dtor_atexitN() { |
---|
942 | // __dtor__...; |
---|
943 | // } |
---|
944 | // int f(...) { |
---|
945 | // ... |
---|
946 | // static bool __objName_uninitialized = true; |
---|
947 | // if (__objName_uninitialized) { |
---|
948 | // __ctor(__objName); |
---|
949 | // __objName_uninitialized = false; |
---|
950 | // atexit(__objName_dtor_atexitN); |
---|
951 | // } |
---|
952 | // ... |
---|
953 | // } |
---|
954 | |
---|
955 | static UniqueName dtorCallerNamer( "_dtor_atexit" ); |
---|
956 | |
---|
957 | // static bool __objName_uninitialized = true |
---|
958 | auto boolType = new ast::BasicType( ast::BasicType::Kind::Bool ); |
---|
959 | auto boolInitExpr = new ast::SingleInit(loc, ast::ConstantExpr::from_int(loc, 1 ) ); |
---|
960 | auto isUninitializedVar = new ast::ObjectDecl(loc, objDecl->mangleName + "_uninitialized", boolType, boolInitExpr, ast::Storage::Static, ast::Linkage::Cforall); |
---|
961 | isUninitializedVar->fixUniqueId(); |
---|
962 | |
---|
963 | // __objName_uninitialized = false; |
---|
964 | auto setTrue = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "?=?" ) ); |
---|
965 | setTrue->args.push_back( new ast::VariableExpr(loc, isUninitializedVar ) ); |
---|
966 | setTrue->args.push_back( ast::ConstantExpr::from_int(loc, 0 ) ); |
---|
967 | |
---|
968 | // generate body of if |
---|
969 | auto initStmts = new ast::CompoundStmt(loc); |
---|
970 | auto & body = initStmts->kids; |
---|
971 | body.push_back( ctor ); |
---|
972 | body.push_back( new ast::ExprStmt(loc, setTrue ) ); |
---|
973 | |
---|
974 | // put it all together |
---|
975 | auto ifStmt = new ast::IfStmt(loc, new ast::VariableExpr(loc, isUninitializedVar ), initStmts, 0 ); |
---|
976 | stmtsToAddAfter.push_back( new ast::DeclStmt(loc, isUninitializedVar ) ); |
---|
977 | stmtsToAddAfter.push_back( ifStmt ); |
---|
978 | |
---|
979 | const ast::Stmt * dtor = ctorInit->dtor; |
---|
980 | |
---|
981 | // these should be automatically managed once reassigned |
---|
982 | // objDecl->set_init( nullptr ); |
---|
983 | // ctorInit->set_ctor( nullptr ); |
---|
984 | // ctorInit->set_dtor( nullptr ); |
---|
985 | if ( dtor ) { |
---|
986 | // if the object has a non-trivial destructor, have to |
---|
987 | // hoist it and the object into the global space and |
---|
988 | // call the destructor function with atexit. |
---|
989 | |
---|
990 | // Statement * dtorStmt = dtor->clone(); |
---|
991 | |
---|
992 | // void __objName_dtor_atexitN(...) {...} |
---|
993 | ast::FunctionDecl * dtorCaller = new ast::FunctionDecl(loc, objDecl->mangleName + dtorCallerNamer.newName(), {}, {}, {}, new ast::CompoundStmt(loc, {dtor}), ast::Storage::Static, ast::Linkage::C ); |
---|
994 | dtorCaller->fixUniqueId(); |
---|
995 | // dtorCaller->stmts->push_back( dtor ); |
---|
996 | |
---|
997 | // atexit(dtor_atexit); |
---|
998 | auto callAtexit = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "atexit" ) ); |
---|
999 | callAtexit->args.push_back( new ast::VariableExpr(loc, dtorCaller ) ); |
---|
1000 | |
---|
1001 | body.push_back( new ast::ExprStmt(loc, callAtexit ) ); |
---|
1002 | |
---|
1003 | // hoist variable and dtor caller decls to list of decls that will be added into global scope |
---|
1004 | staticDtorDecls.push_back( objDecl ); |
---|
1005 | staticDtorDecls.push_back( dtorCaller ); |
---|
1006 | |
---|
1007 | // need to rename object uniquely since it now appears |
---|
1008 | // at global scope and there could be multiple function-scoped |
---|
1009 | // static variables with the same name in different functions. |
---|
1010 | // Note: it isn't sufficient to modify only the mangleName, because |
---|
1011 | // then subsequent Indexer passes can choke on seeing the object's name |
---|
1012 | // if another object has the same name and type. An unfortunate side-effect |
---|
1013 | // of renaming the object is that subsequent NameExprs may fail to resolve, |
---|
1014 | // but there shouldn't be any remaining past this point. |
---|
1015 | static UniqueName staticNamer( "_static_var" ); |
---|
1016 | objDecl->name = objDecl->name + staticNamer.newName(); |
---|
1017 | objDecl->mangleName = Mangle::mangle( objDecl ); |
---|
1018 | |
---|
1019 | // xxx - temporary hack: need to return a declaration, but want to hoist the current object out of this scope |
---|
1020 | // create a new object which is never used |
---|
1021 | static UniqueName dummyNamer( "_dummy" ); |
---|
1022 | auto dummy = new ast::ObjectDecl(loc, dummyNamer.newName(), new ast::PointerType(new ast::VoidType()), nullptr, ast::Storage::Static, ast::Linkage::Cforall, 0, { new ast::Attribute("unused") } ); |
---|
1023 | // delete ctorInit; |
---|
1024 | return dummy; |
---|
1025 | } else { |
---|
1026 | objDecl->init = nullptr; |
---|
1027 | return objDecl; |
---|
1028 | } |
---|
1029 | } else { |
---|
1030 | auto implicit = strict_dynamic_cast< const ast::ImplicitCtorDtorStmt * > ( ctor ); |
---|
1031 | auto ctorStmt = implicit->callStmt.as<ast::ExprStmt>(); |
---|
1032 | const ast::ApplicationExpr * ctorCall = nullptr; |
---|
1033 | if ( ctorStmt && (ctorCall = isIntrinsicCallExpr( ctorStmt->expr )) && ctorCall->args.size() == 2 ) { |
---|
1034 | // clean up intrinsic copy constructor calls by making them into SingleInits |
---|
1035 | const ast::Expr * ctorArg = ctorCall->args.back(); |
---|
1036 | // ctorCall should be gone afterwards |
---|
1037 | auto mutArg = mutate(ctorArg); |
---|
1038 | mutArg->env = ctorCall->env; |
---|
1039 | // std::swap( ctorArg->env, ctorCall->env ); |
---|
1040 | objDecl->init = new ast::SingleInit(loc, mutArg ); |
---|
1041 | |
---|
1042 | // ctorCall->args.pop_back(); |
---|
1043 | } else { |
---|
1044 | stmtsToAddAfter.push_back( ctor ); |
---|
1045 | objDecl->init = nullptr; |
---|
1046 | // ctorInit->ctor = nullptr; |
---|
1047 | } |
---|
1048 | |
---|
1049 | const ast::Stmt * dtor = ctorInit->dtor; |
---|
1050 | if ( dtor ) { |
---|
1051 | auto implicit = strict_dynamic_cast< const ast::ImplicitCtorDtorStmt * >( dtor ); |
---|
1052 | const ast::Stmt * dtorStmt = implicit->callStmt; |
---|
1053 | |
---|
1054 | // don't need to call intrinsic dtor, because it does nothing, but |
---|
1055 | // non-intrinsic dtors must be called |
---|
1056 | if ( ! isIntrinsicSingleArgCallStmt( dtorStmt ) ) { |
---|
1057 | // set dtor location to the object's location for error messages |
---|
1058 | auto dtorFunc = getDtorFunc( objDecl, dtorStmt, stmtsToAddBefore ); |
---|
1059 | objDecl->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr(loc, dtorFunc ) } ) ); |
---|
1060 | // ctorInit->dtor = nullptr; |
---|
1061 | } // if |
---|
1062 | } |
---|
1063 | } // if |
---|
1064 | } else if ( const ast::Init * init = ctorInit->init ) { |
---|
1065 | objDecl->init = init; |
---|
1066 | // ctorInit->init = nullptr; |
---|
1067 | } else { |
---|
1068 | // no constructor and no initializer, which is okay |
---|
1069 | objDecl->init = nullptr; |
---|
1070 | } // if |
---|
1071 | // delete ctorInit; |
---|
1072 | return objDecl; |
---|
1073 | } // if |
---|
1074 | return _objDecl; |
---|
1075 | } |
---|
1076 | |
---|
1077 | void ObjDeclCollector::previsit( const ast::CompoundStmt * ) { |
---|
1078 | GuardValue( curVars ); |
---|
1079 | } |
---|
1080 | |
---|
1081 | void ObjDeclCollector::previsit( const ast::DeclStmt * stmt ) { |
---|
1082 | // keep track of all variables currently in scope |
---|
1083 | if ( auto objDecl = stmt->decl.as<ast::ObjectDecl>() ) { |
---|
1084 | curVars.push_back( objDecl ); |
---|
1085 | } // if |
---|
1086 | } |
---|
1087 | |
---|
1088 | void LabelFinder::previsit( const ast::Stmt * stmt ) { |
---|
1089 | // for each label, remember the variables in scope at that label. |
---|
1090 | for ( auto l : stmt->labels ) { |
---|
1091 | vars[l] = curVars; |
---|
1092 | } // for |
---|
1093 | } |
---|
1094 | |
---|
1095 | void LabelFinder::previsit( const ast::CompoundStmt * stmt ) { |
---|
1096 | previsit( (const ast::Stmt *) stmt ); |
---|
1097 | Parent::previsit( stmt ); |
---|
1098 | } |
---|
1099 | |
---|
1100 | void LabelFinder::previsit( const ast::DeclStmt * stmt ) { |
---|
1101 | previsit( (const ast::Stmt *)stmt ); |
---|
1102 | Parent::previsit( stmt ); |
---|
1103 | } |
---|
1104 | |
---|
1105 | |
---|
1106 | void InsertDtors::previsit( const ast::FunctionDecl * funcDecl ) { |
---|
1107 | // each function needs to have its own set of labels |
---|
1108 | GuardValue( labelVars ); |
---|
1109 | labelVars.clear(); |
---|
1110 | // LabelFinder does not recurse into FunctionDecl, so need to visit |
---|
1111 | // its children manually. |
---|
1112 | if (funcDecl->type) funcDecl->type->accept(finder); |
---|
1113 | // maybeAccept( funcDecl->type, finder ); |
---|
1114 | if (funcDecl->stmts) funcDecl->stmts->accept(finder) ; |
---|
1115 | |
---|
1116 | // all labels for this function have been collected, insert destructors as appropriate via implicit recursion. |
---|
1117 | } |
---|
1118 | |
---|
1119 | // Handle break/continue/goto in the same manner as C++. Basic idea: any objects that are in scope at the |
---|
1120 | // BranchStmt but not at the labelled (target) statement must be destructed. If there are any objects in scope |
---|
1121 | // at the target location but not at the BranchStmt then those objects would be uninitialized so notify the user |
---|
1122 | // of the error. See C++ Reference 6.6 Jump Statements for details. |
---|
1123 | void InsertDtors::handleGoto( const ast::BranchStmt * stmt ) { |
---|
1124 | // can't do anything for computed goto |
---|
1125 | if ( stmt->computedTarget ) return; |
---|
1126 | |
---|
1127 | assertf( stmt->target.name != "", "BranchStmt missing a label: %s", toString( stmt ).c_str() ); |
---|
1128 | // S_L = lvars = set of objects in scope at label definition |
---|
1129 | // S_G = curVars = set of objects in scope at goto statement |
---|
1130 | ObjectSet & lvars = labelVars[ stmt->target ]; |
---|
1131 | |
---|
1132 | DTOR_PRINT( |
---|
1133 | std::cerr << "at goto label: " << stmt->target.name << std::endl; |
---|
1134 | std::cerr << "S_G = " << printSet( curVars ) << std::endl; |
---|
1135 | std::cerr << "S_L = " << printSet( lvars ) << std::endl; |
---|
1136 | ) |
---|
1137 | |
---|
1138 | |
---|
1139 | // std::set_difference requires that the inputs be sorted. |
---|
1140 | lvars.sort(); |
---|
1141 | curVars.sort(); |
---|
1142 | |
---|
1143 | ObjectSet diff; |
---|
1144 | // S_L-S_G results in set of objects whose construction is skipped - it's an error if this set is non-empty |
---|
1145 | std::set_difference( lvars.begin(), lvars.end(), curVars.begin(), curVars.end(), std::inserter( diff, diff.begin() ) ); |
---|
1146 | DTOR_PRINT( |
---|
1147 | std::cerr << "S_L-S_G = " << printSet( diff ) << std::endl; |
---|
1148 | ) |
---|
1149 | if ( ! diff.empty() ) { |
---|
1150 | SemanticError( stmt, std::string("jump to label '") + stmt->target.name + "' crosses initialization of " + (*diff.begin())->name + " " ); |
---|
1151 | } // if |
---|
1152 | } |
---|
1153 | |
---|
1154 | void InsertDtors::previsit( const ast::BranchStmt * stmt ) { |
---|
1155 | switch( stmt->kind ) { |
---|
1156 | case ast::BranchStmt::Continue: |
---|
1157 | case ast::BranchStmt::Break: |
---|
1158 | // could optimize the break/continue case, because the S_L-S_G check is unnecessary (this set should |
---|
1159 | // always be empty), but it serves as a small sanity check. |
---|
1160 | case ast::BranchStmt::Goto: |
---|
1161 | handleGoto( stmt ); |
---|
1162 | break; |
---|
1163 | default: |
---|
1164 | assert( false ); |
---|
1165 | } // switch |
---|
1166 | } |
---|
1167 | |
---|
1168 | bool checkWarnings( const ast::FunctionDecl * funcDecl ) { |
---|
1169 | // only check for warnings if the current function is a user-defined |
---|
1170 | // constructor or destructor |
---|
1171 | if ( ! funcDecl ) return false; |
---|
1172 | if ( ! funcDecl->stmts ) return false; |
---|
1173 | return CodeGen::isCtorDtor( funcDecl->name ) && ! funcDecl->linkage.is_overrideable; |
---|
1174 | } |
---|
1175 | |
---|
1176 | void GenStructMemberCalls::previsit( const ast::FunctionDecl * funcDecl ) { |
---|
1177 | GuardValue( function ); |
---|
1178 | GuardValue( unhandled ); |
---|
1179 | GuardValue( usedUninit ); |
---|
1180 | GuardValue( thisParam ); |
---|
1181 | GuardValue( isCtor ); |
---|
1182 | GuardValue( structDecl ); |
---|
1183 | errors = SemanticErrorException(); // clear previous errors |
---|
1184 | |
---|
1185 | // need to start with fresh sets |
---|
1186 | unhandled.clear(); |
---|
1187 | usedUninit.clear(); |
---|
1188 | |
---|
1189 | function = mutate(funcDecl); |
---|
1190 | // could this be non-unique? |
---|
1191 | if (function != funcDecl) { |
---|
1192 | std::cerr << "GenStructMemberCalls: non-unique FunctionDecl " << funcDecl->location << funcDecl->name << std::endl; |
---|
1193 | } |
---|
1194 | |
---|
1195 | isCtor = CodeGen::isConstructor( function->name ); |
---|
1196 | if ( checkWarnings( function ) ) { |
---|
1197 | // const ast::FunctionType * type = function->type; |
---|
1198 | // assert( ! type->params.empty() ); |
---|
1199 | thisParam = function->params.front().strict_as<ast::ObjectDecl>(); |
---|
1200 | auto thisType = getPointerBase( thisParam->get_type() ); |
---|
1201 | auto structType = dynamic_cast< const ast::StructInstType * >( thisType ); |
---|
1202 | if ( structType ) { |
---|
1203 | structDecl = structType->base; |
---|
1204 | for ( auto & member : structDecl->members ) { |
---|
1205 | if ( auto field = member.as<ast::ObjectDecl>() ) { |
---|
1206 | // record all of the struct type's members that need to be constructed or |
---|
1207 | // destructed by the end of the function |
---|
1208 | unhandled.insert( field ); |
---|
1209 | } |
---|
1210 | } |
---|
1211 | } |
---|
1212 | } |
---|
1213 | } |
---|
1214 | |
---|
1215 | const ast::DeclWithType * GenStructMemberCalls::postvisit( const ast::FunctionDecl * funcDecl ) { |
---|
1216 | // remove the unhandled objects from usedUninit, because a call is inserted |
---|
1217 | // to handle them - only objects that are later constructed are used uninitialized. |
---|
1218 | std::map< const ast::DeclWithType *, CodeLocation > diff; |
---|
1219 | // need the comparator since usedUninit and unhandled have different types |
---|
1220 | struct comp_t { |
---|
1221 | typedef decltype(usedUninit)::value_type usedUninit_t; |
---|
1222 | typedef decltype(unhandled)::value_type unhandled_t; |
---|
1223 | bool operator()(usedUninit_t x, unhandled_t y) { return x.first < y; } |
---|
1224 | bool operator()(unhandled_t x, usedUninit_t y) { return x < y.first; } |
---|
1225 | } comp; |
---|
1226 | std::set_difference( usedUninit.begin(), usedUninit.end(), unhandled.begin(), unhandled.end(), std::inserter( diff, diff.begin() ), comp ); |
---|
1227 | for ( auto p : diff ) { |
---|
1228 | auto member = p.first; |
---|
1229 | auto loc = p.second; |
---|
1230 | // xxx - make error message better by also tracking the location that the object is constructed at? |
---|
1231 | emit( loc, "in ", function->name, ", field ", member->name, " used before being constructed" ); |
---|
1232 | } |
---|
1233 | |
---|
1234 | const CodeLocation loc = funcDecl->location; |
---|
1235 | |
---|
1236 | if ( ! unhandled.empty() ) { |
---|
1237 | auto mutStmts = function->stmts.get_and_mutate(); |
---|
1238 | // need to explicitly re-add function parameters to the indexer in order to resolve copy constructors |
---|
1239 | auto guard = makeFuncGuard( [this]() { symtab.enterScope(); }, [this]() { symtab.leaveScope(); } ); |
---|
1240 | symtab.addFunction( function ); |
---|
1241 | |
---|
1242 | // need to iterate through members in reverse in order for |
---|
1243 | // ctor/dtor statements to come out in the right order |
---|
1244 | for ( auto & member : reverseIterate( structDecl->members ) ) { |
---|
1245 | auto field = member.as<ast::ObjectDecl>(); |
---|
1246 | // skip non-DWT members |
---|
1247 | if ( ! field ) continue; |
---|
1248 | // skip non-constructable members |
---|
1249 | if ( ! tryConstruct( field ) ) continue; |
---|
1250 | // skip handled members |
---|
1251 | if ( ! unhandled.count( field ) ) continue; |
---|
1252 | |
---|
1253 | // insert and resolve default/copy constructor call for each field that's unhandled |
---|
1254 | // std::list< const ast::Stmt * > stmt; |
---|
1255 | ast::Expr * arg2 = nullptr; |
---|
1256 | if ( function->name == "?{}" && isCopyFunction( function ) ) { |
---|
1257 | // if copy ctor, need to pass second-param-of-this-function.field |
---|
1258 | // std::list< DeclarationWithType * > & params = function->get_functionType()->get_parameters(); |
---|
1259 | assert( function->params.size() == 2 ); |
---|
1260 | arg2 = new ast::MemberExpr(funcDecl->location, field, new ast::VariableExpr(funcDecl->location, function->params.back() ) ); |
---|
1261 | } |
---|
1262 | InitExpander_new srcParam( arg2 ); |
---|
1263 | // cast away reference type and construct field. |
---|
1264 | ast::Expr * thisExpr = new ast::CastExpr(funcDecl->location, new ast::VariableExpr(funcDecl->location, thisParam ), thisParam->get_type()->stripReferences()); |
---|
1265 | ast::Expr * memberDest = new ast::MemberExpr(funcDecl->location, field, thisExpr ); |
---|
1266 | ast::ptr<ast::Stmt> callStmt = SymTab::genImplicitCall( srcParam, memberDest, loc, function->name, field, static_cast<SymTab::LoopDirection>(isCtor) ); |
---|
1267 | |
---|
1268 | if ( callStmt ) { |
---|
1269 | // auto & callStmt = stmt.front(); |
---|
1270 | |
---|
1271 | try { |
---|
1272 | callStmt = callStmt->accept( *visitor ); |
---|
1273 | if ( isCtor ) { |
---|
1274 | mutStmts->push_front( callStmt ); |
---|
1275 | } else { // TODO: don't generate destructor function/object for intrinsic calls |
---|
1276 | // destructor statements should be added at the end |
---|
1277 | // function->get_statements()->push_back( callStmt ); |
---|
1278 | |
---|
1279 | // Optimization: do not need to call intrinsic destructors on members |
---|
1280 | if ( isIntrinsicSingleArgCallStmt( callStmt ) ) continue; |
---|
1281 | |
---|
1282 | // __Destructor _dtor0 = { (void *)&b.a1, (void (*)(void *)_destroy_A }; |
---|
1283 | std::list< ast::ptr<ast::Stmt> > stmtsToAdd; |
---|
1284 | |
---|
1285 | static UniqueName memberDtorNamer = { "__memberDtor" }; |
---|
1286 | assertf( Validate::dtorStruct, "builtin __Destructor not found." ); |
---|
1287 | assertf( Validate::dtorStructDestroy, "builtin __destroy_Destructor not found." ); |
---|
1288 | |
---|
1289 | ast::Expr * thisExpr = new ast::CastExpr( new ast::AddressExpr( new ast::VariableExpr(loc, thisParam ) ), new ast::PointerType( new ast::VoidType(), ast::CV::Qualifiers() ) ); |
---|
1290 | ast::Expr * dtorExpr = new ast::VariableExpr(loc, getDtorFunc( thisParam, callStmt, stmtsToAdd ) ); |
---|
1291 | |
---|
1292 | // cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings |
---|
1293 | auto dtorFtype = new ast::FunctionType(); |
---|
1294 | dtorFtype->params.emplace_back( new ast::PointerType( new ast::VoidType() ) ); |
---|
1295 | auto dtorType = new ast::PointerType( dtorFtype ); |
---|
1296 | |
---|
1297 | auto destructor = new ast::ObjectDecl(loc, memberDtorNamer.newName(), new ast::StructInstType( ast::dtorStruct ), new ast::ListInit(loc, { new ast::SingleInit(loc, thisExpr ), new ast::SingleInit(loc, new ast::CastExpr( dtorExpr, dtorType ) ) } ) ); |
---|
1298 | destructor->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr({}, ast::dtorStructDestroy ) } ) ); |
---|
1299 | mutStmts->push_front( new ast::DeclStmt(loc, destructor ) ); |
---|
1300 | mutStmts->kids.splice( mutStmts->kids.begin(), stmtsToAdd ); |
---|
1301 | } |
---|
1302 | } catch ( SemanticErrorException & error ) { |
---|
1303 | emit( funcDecl->location, "in ", function->name , ", field ", field->name, " not explicitly ", isCtor ? "constructed" : "destructed", " and no ", isCtor ? "default constructor" : "destructor", " found" ); |
---|
1304 | } |
---|
1305 | } |
---|
1306 | } |
---|
1307 | function->stmts = mutStmts; |
---|
1308 | } |
---|
1309 | if (! errors.isEmpty()) { |
---|
1310 | throw errors; |
---|
1311 | } |
---|
1312 | // return funcDecl; |
---|
1313 | return function; |
---|
1314 | } |
---|
1315 | |
---|
1316 | /// true if expr is effectively just the 'this' parameter |
---|
1317 | bool isThisExpression( const ast::Expr * expr, const ast::DeclWithType * thisParam ) { |
---|
1318 | // TODO: there are more complicated ways to pass 'this' to a constructor, e.g. &*, *&, etc. |
---|
1319 | if ( auto varExpr = dynamic_cast< const ast::VariableExpr * >( expr ) ) { |
---|
1320 | return varExpr->var == thisParam; |
---|
1321 | } else if ( auto castExpr = dynamic_cast< const ast::CastExpr * > ( expr ) ) { |
---|
1322 | return isThisExpression( castExpr->arg, thisParam ); |
---|
1323 | } |
---|
1324 | return false; |
---|
1325 | } |
---|
1326 | |
---|
1327 | /// returns a MemberExpr if expr is effectively just member access on the 'this' parameter, else nullptr |
---|
1328 | const ast::MemberExpr * isThisMemberExpr( const ast::Expr * expr, const ast::DeclWithType * thisParam ) { |
---|
1329 | if ( auto memberExpr = dynamic_cast< const ast::MemberExpr * >( expr ) ) { |
---|
1330 | if ( isThisExpression( memberExpr->aggregate, thisParam ) ) { |
---|
1331 | return memberExpr; |
---|
1332 | } |
---|
1333 | } else if ( auto castExpr = dynamic_cast< const ast::CastExpr * >( expr ) ) { |
---|
1334 | return isThisMemberExpr( castExpr->arg, thisParam ); |
---|
1335 | } |
---|
1336 | return nullptr; |
---|
1337 | } |
---|
1338 | |
---|
1339 | void GenStructMemberCalls::previsit( const ast::ApplicationExpr * appExpr ) { |
---|
1340 | if ( ! checkWarnings( function ) ) { |
---|
1341 | visit_children = false; |
---|
1342 | return; |
---|
1343 | } |
---|
1344 | |
---|
1345 | std::string fname = getFunctionName( appExpr ); |
---|
1346 | if ( fname == function->name ) { |
---|
1347 | // call to same kind of function |
---|
1348 | const ast::Expr * firstParam = appExpr->args.front(); |
---|
1349 | |
---|
1350 | if ( isThisExpression( firstParam, thisParam ) ) { |
---|
1351 | // if calling another constructor on thisParam, assume that function handles |
---|
1352 | // all members - if it doesn't a warning will appear in that function. |
---|
1353 | unhandled.clear(); |
---|
1354 | } else if ( auto memberExpr = isThisMemberExpr( firstParam, thisParam ) ) { |
---|
1355 | // if first parameter is a member expression on the this parameter, |
---|
1356 | // then remove the member from unhandled set. |
---|
1357 | if ( isThisExpression( memberExpr->aggregate, thisParam ) ) { |
---|
1358 | unhandled.erase( memberExpr->member ); |
---|
1359 | } |
---|
1360 | } |
---|
1361 | } |
---|
1362 | } |
---|
1363 | |
---|
1364 | void GenStructMemberCalls::previsit( const ast::MemberExpr * memberExpr ) { |
---|
1365 | if ( ! checkWarnings( function ) || ! isCtor ) { |
---|
1366 | visit_children = false; |
---|
1367 | return; |
---|
1368 | } |
---|
1369 | |
---|
1370 | if ( isThisExpression( memberExpr->aggregate, thisParam ) ) { |
---|
1371 | if ( unhandled.count( memberExpr->member ) ) { |
---|
1372 | // emit a warning because a member was used before it was constructed |
---|
1373 | usedUninit.insert( { memberExpr->member, memberExpr->location } ); |
---|
1374 | } |
---|
1375 | } |
---|
1376 | } |
---|
1377 | |
---|
1378 | template< typename Visitor, typename... Params > |
---|
1379 | void error( Visitor & v, CodeLocation loc, const Params &... params ) { |
---|
1380 | SemanticErrorException err( loc, toString( params... ) ); |
---|
1381 | v.errors.append( err ); |
---|
1382 | } |
---|
1383 | |
---|
1384 | template< typename... Params > |
---|
1385 | void GenStructMemberCalls::emit( CodeLocation loc, const Params &... params ) { |
---|
1386 | // toggle warnings vs. errors here. |
---|
1387 | // warn( params... ); |
---|
1388 | error( *this, loc, params... ); |
---|
1389 | } |
---|
1390 | |
---|
1391 | const ast::Expr * GenStructMemberCalls::postvisit( const ast::UntypedExpr * untypedExpr ) { |
---|
1392 | // Expression * newExpr = untypedExpr; |
---|
1393 | // xxx - functions returning ast::ptr seems wrong... |
---|
1394 | auto res = ResolvExpr::findVoidExpression( untypedExpr, symtab ); |
---|
1395 | return res.release(); |
---|
1396 | // return newExpr; |
---|
1397 | } |
---|
1398 | |
---|
1399 | void InsertImplicitCalls::previsit(const ast::UniqueExpr * unqExpr) { |
---|
1400 | if (visitedIds.count(unqExpr->id)) visit_children = false; |
---|
1401 | else visitedIds.insert(unqExpr->id); |
---|
1402 | } |
---|
1403 | |
---|
1404 | const ast::Expr * FixCtorExprs::postvisit( const ast::ConstructorExpr * ctorExpr ) { |
---|
1405 | const CodeLocation loc = ctorExpr->location; |
---|
1406 | static UniqueName tempNamer( "_tmp_ctor_expr" ); |
---|
1407 | // xxx - is the size check necessary? |
---|
1408 | assert( ctorExpr->result && ctorExpr->result->size() == 1 ); |
---|
1409 | |
---|
1410 | // xxx - this can be TupleAssignExpr now. Need to properly handle this case. |
---|
1411 | // take possession of expr and env |
---|
1412 | ast::ptr<ast::ApplicationExpr> callExpr = ctorExpr->callExpr.strict_as<ast::ApplicationExpr>(); |
---|
1413 | ast::ptr<ast::TypeSubstitution> env = ctorExpr->env; |
---|
1414 | // ctorExpr->set_callExpr( nullptr ); |
---|
1415 | // ctorExpr->set_env( nullptr ); |
---|
1416 | |
---|
1417 | // xxx - ideally we would reuse the temporary generated from the copy constructor passes from within firstArg if it exists and not generate a temporary if it's unnecessary. |
---|
1418 | auto tmp = new ast::ObjectDecl(loc, tempNamer.newName(), callExpr->args.front()->result ); |
---|
1419 | declsToAddBefore.push_back( tmp ); |
---|
1420 | // delete ctorExpr; |
---|
1421 | |
---|
1422 | // build assignment and replace constructor's first argument with new temporary |
---|
1423 | auto mutCallExpr = callExpr.get_and_mutate(); |
---|
1424 | const ast::Expr * firstArg = callExpr->args.front(); |
---|
1425 | ast::Expr * assign = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "?=?" ), { new ast::AddressExpr(loc, new ast::VariableExpr(loc, tmp ) ), new ast::AddressExpr( firstArg ) } ); |
---|
1426 | firstArg = new ast::VariableExpr(loc, tmp ); |
---|
1427 | mutCallExpr->args.front() = firstArg; |
---|
1428 | |
---|
1429 | // resolve assignment and dispose of new env |
---|
1430 | auto resolved = ResolvExpr::findVoidExpression( assign, symtab ); |
---|
1431 | auto mut = resolved.get_and_mutate(); |
---|
1432 | assertf(resolved.get() == mut, "newly resolved expression must be unique"); |
---|
1433 | mut->env = nullptr; |
---|
1434 | |
---|
1435 | // for constructor expr: |
---|
1436 | // T x; |
---|
1437 | // x{}; |
---|
1438 | // results in: |
---|
1439 | // T x; |
---|
1440 | // T & tmp; |
---|
1441 | // &tmp = &x, ?{}(tmp), tmp |
---|
1442 | ast::CommaExpr * commaExpr = new ast::CommaExpr(loc, resolved, new ast::CommaExpr(loc, mutCallExpr, new ast::VariableExpr(loc, tmp ) ) ); |
---|
1443 | commaExpr->env = env; |
---|
1444 | return commaExpr; |
---|
1445 | } |
---|
1446 | } // namespace |
---|
1447 | } // namespace InitTweak |
---|
1448 | |
---|
1449 | // Local Variables: // |
---|
1450 | // tab-width: 4 // |
---|
1451 | // mode: c++ // |
---|
1452 | // compile-command: "make install" // |
---|
1453 | // End: // |
---|