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 | // Lvalue.cc -- |
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8 | // |
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9 | // Author : Richard C. Bilson |
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10 | // Created On : Mon May 18 07:44:20 2015 |
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11 | // Last Modified By : Peter A. Buhr |
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12 | // Last Modified On : Fri Mar 17 09:11:18 2017 |
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13 | // Update Count : 5 |
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14 | // |
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15 | |
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16 | #include <cassert> // for strict_dynamic_cast |
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17 | #include <string> // for string |
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18 | |
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19 | #include "Common/PassVisitor.h" |
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20 | #include "GenPoly.h" // for isPolyType |
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21 | #include "Lvalue.h" |
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22 | |
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23 | #include "Parser/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic |
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24 | #include "ResolvExpr/TypeEnvironment.h" // for AssertionSet, OpenVarSet |
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25 | #include "ResolvExpr/Unify.h" // for unify |
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26 | #include "ResolvExpr/typeops.h" |
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27 | #include "SymTab/Autogen.h" |
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28 | #include "SymTab/Indexer.h" // for Indexer |
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29 | #include "SynTree/Declaration.h" // for Declaration, FunctionDecl |
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30 | #include "SynTree/Expression.h" // for Expression, ConditionalExpr |
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31 | #include "SynTree/Mutator.h" // for mutateAll, Mutator |
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32 | #include "SynTree/Statement.h" // for ReturnStmt, Statement (ptr o... |
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33 | #include "SynTree/Type.h" // for PointerType, Type, FunctionType |
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34 | #include "SynTree/Visitor.h" // for Visitor, acceptAll |
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35 | |
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36 | #if 0 |
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37 | #define PRINT(x) x |
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38 | #else |
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39 | #define PRINT(x) |
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40 | #endif |
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41 | |
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42 | namespace GenPoly { |
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43 | namespace { |
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44 | // TODO: fold this into the general createDeref function?? |
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45 | Expression * mkDeref( Expression * arg ) { |
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46 | if ( SymTab::dereferenceOperator ) { |
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47 | // note: reference depth can be arbitrarily deep here, so peel off the outermost pointer/reference, not just pointer because they are effecitvely equivalent in this pass |
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48 | VariableExpr * deref = new VariableExpr( SymTab::dereferenceOperator ); |
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49 | deref->result = new PointerType( Type::Qualifiers(), deref->result ); |
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50 | Type * base = InitTweak::getPointerBase( arg->result ); |
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51 | assertf( base, "expected pointer type in dereference (type was %s)", toString( arg->result ).c_str() ); |
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52 | ApplicationExpr * ret = new ApplicationExpr( deref, { arg } ); |
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53 | delete ret->result; |
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54 | ret->result = base->clone(); |
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55 | ret->result->set_lvalue( true ); |
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56 | return ret; |
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57 | } else { |
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58 | return UntypedExpr::createDeref( arg ); |
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59 | } |
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60 | } |
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61 | |
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62 | struct ReferenceConversions final : public WithStmtsToAdd { |
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63 | Expression * postmutate( CastExpr * castExpr ); |
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64 | Expression * postmutate( AddressExpr * addrExpr ); |
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65 | }; |
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66 | |
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67 | /// Intrinsic functions that take reference parameters don't REALLY take reference parameters -- their reference arguments must always be implicitly dereferenced. |
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68 | struct FixIntrinsicArgs final { |
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69 | Expression * postmutate( ApplicationExpr * appExpr ); |
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70 | }; |
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71 | |
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72 | struct FixIntrinsicResult final : public WithGuards { |
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73 | Expression * postmutate( ApplicationExpr * appExpr ); |
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74 | void premutate( FunctionDecl * funcDecl ); |
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75 | bool inIntrinsic = false; |
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76 | }; |
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77 | |
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78 | /// Replace reference types with pointer types |
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79 | struct ReferenceTypeElimination final { |
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80 | Type * postmutate( ReferenceType * refType ); |
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81 | }; |
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82 | |
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83 | /// GCC-like Generalized Lvalues (which have since been removed from GCC) |
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84 | /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues |
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85 | /// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c) |
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86 | struct GeneralizedLvalue final : public WithVisitorRef<GeneralizedLvalue> { |
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87 | Expression * postmutate( AddressExpr * addressExpr ); |
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88 | Expression * postmutate( MemberExpr * memExpr ); |
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89 | |
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90 | template<typename Func> |
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91 | Expression * applyTransformation( Expression * expr, Expression * arg, Func mkExpr ); |
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92 | }; |
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93 | |
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94 | /// Removes redundant &*/*& pattern that this pass can generate |
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95 | struct CollapseAddrDeref final { |
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96 | Expression * postmutate( AddressExpr * addressExpr ); |
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97 | Expression * postmutate( ApplicationExpr * appExpr ); |
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98 | }; |
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99 | |
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100 | struct AddrRef final : public WithGuards, public WithVisitorRef<AddrRef>, public WithShortCircuiting { |
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101 | void premutate( AddressExpr * addrExpr ); |
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102 | Expression * postmutate( AddressExpr * addrExpr ); |
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103 | void premutate( Expression * expr ); |
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104 | void premutate( ApplicationExpr * appExpr ); |
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105 | void premutate( SingleInit * init ); |
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106 | |
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107 | void handleNonAddr( Expression * ); |
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108 | |
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109 | bool first = true; |
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110 | bool current = false; |
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111 | int refDepth = 0; |
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112 | bool addCast = false; |
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113 | }; |
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114 | } // namespace |
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115 | |
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116 | static bool referencesEliminated = false; |
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117 | // used by UntypedExpr::createDeref to determine whether result type of dereference should be ReferenceType or value type. |
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118 | bool referencesPermissable() { |
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119 | return ! referencesEliminated; |
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120 | } |
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121 | |
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122 | void convertLvalue( std::list< Declaration* > & translationUnit ) { |
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123 | PassVisitor<ReferenceConversions> refCvt; |
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124 | PassVisitor<ReferenceTypeElimination> elim; |
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125 | PassVisitor<GeneralizedLvalue> genLval; |
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126 | PassVisitor<FixIntrinsicArgs> fixer; |
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127 | PassVisitor<CollapseAddrDeref> collapser; |
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128 | PassVisitor<AddrRef> addrRef; |
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129 | PassVisitor<FixIntrinsicResult> intrinsicResults; |
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130 | mutateAll( translationUnit, intrinsicResults ); |
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131 | mutateAll( translationUnit, addrRef ); |
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132 | mutateAll( translationUnit, refCvt ); |
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133 | mutateAll( translationUnit, fixer ); |
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134 | mutateAll( translationUnit, collapser ); |
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135 | mutateAll( translationUnit, genLval ); |
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136 | mutateAll( translationUnit, elim ); // last because other passes need reference types to work |
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137 | |
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138 | // from this point forward, no other pass should create reference types. |
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139 | referencesEliminated = true; |
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140 | } |
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141 | |
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142 | Expression * generalizedLvalue( Expression * expr ) { |
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143 | PassVisitor<GeneralizedLvalue> genLval; |
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144 | return expr->acceptMutator( genLval ); |
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145 | } |
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146 | |
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147 | namespace { |
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148 | // true for intrinsic function calls that return an lvalue in C |
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149 | bool isIntrinsicReference( Expression * expr ) { |
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150 | // known intrinsic-reference prelude functions |
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151 | static std::set<std::string> lvalueFunctions = { "*?", "?[?]" }; |
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152 | if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) { |
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153 | std::string fname = InitTweak::getFunctionName( untyped ); |
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154 | return lvalueFunctions.count(fname); |
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155 | } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) { |
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156 | if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) { |
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157 | return func->linkage == LinkageSpec::Intrinsic && lvalueFunctions.count(func->name); |
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158 | } |
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159 | } |
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160 | return false; |
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161 | } |
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162 | |
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163 | Expression * FixIntrinsicResult::postmutate( ApplicationExpr * appExpr ) { |
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164 | if ( isIntrinsicReference( appExpr ) ) { |
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165 | // eliminate reference types from intrinsic applications - now they return lvalues |
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166 | ReferenceType * result = strict_dynamic_cast< ReferenceType * >( appExpr->result ); |
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167 | appExpr->result = result->base->clone(); |
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168 | appExpr->result->set_lvalue( true ); |
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169 | if ( ! inIntrinsic ) { |
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170 | // when not in an intrinsic function, add a cast to |
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171 | // don't add cast when in an intrinsic function, since they already have the cast |
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172 | Expression * ret = new CastExpr( appExpr, result ); |
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173 | std::swap( ret->env, appExpr->env ); |
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174 | return ret; |
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175 | } |
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176 | delete result; |
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177 | } |
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178 | return appExpr; |
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179 | } |
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180 | |
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181 | void FixIntrinsicResult::premutate( FunctionDecl * funcDecl ) { |
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182 | GuardValue( inIntrinsic ); |
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183 | inIntrinsic = funcDecl->linkage == LinkageSpec::Intrinsic; |
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184 | } |
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185 | |
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186 | Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) { |
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187 | // intrinsic functions don't really take reference-typed parameters, so they require an implicit dereference on their arguments. |
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188 | if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) { |
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189 | FunctionType * ftype = GenPoly::getFunctionType( function->get_type() ); |
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190 | assertf( ftype, "Function declaration does not have function type." ); |
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191 | // can be of differing lengths only when function is variadic |
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192 | assertf( ftype->parameters.size() == appExpr->args.size() || ftype->isVarArgs, "ApplicationExpr args do not match formal parameter type." ); |
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193 | |
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194 | |
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195 | unsigned int i = 0; |
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196 | const unsigned int end = ftype->parameters.size(); |
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197 | for ( auto p : unsafe_group_iterate( appExpr->args, ftype->parameters ) ) { |
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198 | if (i == end) break; |
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199 | Expression *& arg = std::get<0>( p ); |
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200 | Type * formal = std::get<1>( p )->get_type(); |
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201 | PRINT( |
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202 | std::cerr << "pair<0>: " << arg << std::endl; |
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203 | std::cerr << " -- " << arg->result << std::endl; |
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204 | std::cerr << "pair<1>: " << formal << std::endl; |
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205 | ) |
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206 | if ( dynamic_cast<ReferenceType*>( formal ) ) { |
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207 | PRINT( |
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208 | std::cerr << "===formal is reference" << std::endl; |
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209 | ) |
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210 | // TODO: it's likely that the second condition should be ... && ! isIntrinsicReference( arg ), but this requires investigation. |
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211 | |
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212 | if ( function->linkage != LinkageSpec::Intrinsic && isIntrinsicReference( arg ) ) { |
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213 | // needed for definition of prelude functions, etc. |
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214 | // if argument is dereference or array subscript, the result isn't REALLY a reference, but non-intrinsic functions expect a reference: take address |
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215 | |
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216 | // NOTE: previously, this condition fixed |
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217 | // void f(int *&); |
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218 | // int & x = ...; |
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219 | // f(&x); |
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220 | // But now this is taken care of by a reference cast added by AddrRef. Need to find a new |
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221 | // example or remove this branch. |
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222 | |
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223 | PRINT( |
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224 | std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl; |
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225 | ) |
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226 | arg = new AddressExpr( arg ); |
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227 | // } else if ( function->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getPointerBase( arg->result ) ) { |
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228 | } else if ( function->linkage == LinkageSpec::Intrinsic && arg->result->referenceDepth() != 0 ) { |
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229 | // argument is a 'real' reference, but function expects a C lvalue: add a dereference to the reference-typed argument |
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230 | PRINT( |
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231 | std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl; |
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232 | ) |
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233 | Type * baseType = InitTweak::getPointerBase( arg->result ); |
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234 | assertf( baseType, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() ); |
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235 | PointerType * ptrType = new PointerType( Type::Qualifiers(), baseType->clone() ); |
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236 | delete arg->result; |
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237 | arg->result = ptrType; |
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238 | arg = mkDeref( arg ); |
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239 | // assertf( arg->result->referenceDepth() == 0, "Reference types should have been eliminated from intrinsic function calls, but weren't: %s", toCString( arg->result ) ); |
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240 | } |
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241 | } |
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242 | ++i; |
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243 | } |
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244 | } |
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245 | return appExpr; |
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246 | } |
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247 | |
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248 | // idea: &&&E: get outer &, inner & |
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249 | // at inner &, record depth D of reference type of argument of & |
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250 | // at outer &, add D derefs. |
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251 | void AddrRef::handleNonAddr( Expression * ) { |
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252 | // non-address-of: reset status variables: |
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253 | // * current expr is NOT the first address-of expr in an address-of chain |
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254 | // * next seen address-of expr IS the first in the chain. |
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255 | GuardValue( current ); |
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256 | GuardValue( first ); |
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257 | current = false; |
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258 | first = true; |
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259 | } |
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260 | |
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261 | void AddrRef::premutate( Expression * expr ) { |
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262 | handleNonAddr( expr ); |
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263 | GuardValue( addCast ); |
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264 | addCast = false; |
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265 | } |
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266 | |
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267 | void AddrRef::premutate( AddressExpr * ) { |
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268 | GuardValue( current ); |
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269 | GuardValue( first ); |
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270 | current = first; // is this the first address-of in the chain? |
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271 | first = false; // from here out, no longer possible for next address-of to be first in chain |
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272 | if ( current ) { // this is the outermost address-of in a chain |
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273 | GuardValue( refDepth ); |
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274 | refDepth = 0; // set depth to 0 so that postmutate can find the innermost address-of easily |
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275 | } |
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276 | } |
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277 | |
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278 | Expression * AddrRef::postmutate( AddressExpr * addrExpr ) { |
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279 | PRINT( std::cerr << "addr ref at " << addrExpr << std::endl; ) |
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280 | if ( refDepth == 0 ) { |
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281 | PRINT( std::cerr << "depth 0, get new depth..." << std::endl; ) |
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282 | // this is the innermost address-of in a chain, record depth D |
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283 | if ( ! isIntrinsicReference( addrExpr->arg ) ) { |
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284 | // try to avoid ?[?] |
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285 | // xxx - is this condition still necessary? intrinsicReferences should have a cast around them at this point, so I don't think this condition ever fires. |
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286 | refDepth = addrExpr->arg->result->referenceDepth(); |
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287 | PRINT( std::cerr << "arg not intrinsic reference, new depth is: " << refDepth << std::endl; ) |
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288 | } else { |
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289 | assertf( false, "AddrRef : address-of should not have intrinsic reference argument: %s", toCString( addrExpr->arg ) ); |
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290 | } |
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291 | } |
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292 | if ( current ) { // this is the outermost address-of in a chain |
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293 | PRINT( std::cerr << "current, depth is: " << refDepth << std::endl; ) |
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294 | Expression * ret = addrExpr; |
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295 | while ( refDepth ) { |
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296 | // add one dereference for each |
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297 | ret = mkDeref( ret ); |
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298 | refDepth--; |
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299 | } |
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300 | |
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301 | // if addrExpr depth is 0, then the result is a pointer because the arg was depth 1 and not lvalue. |
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302 | // This means the dereference result is not a reference, is lvalue, and one less pointer depth than |
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303 | // the addrExpr. Thus the cast is meaningless. |
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304 | // TODO: One thing to double check is whether it is possible for the types to differ outside of the single |
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305 | // pointer level (i.e. can the base type of addrExpr differ from the type of addrExpr-arg?). |
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306 | // If so then the cast might need to be added, conditional on a more sophisticated check. |
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307 | if ( addCast && addrExpr->result->referenceDepth() != 0 ) { |
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308 | PRINT( std::cerr << "adding cast to " << addrExpr->result << std::endl; ) |
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309 | return new CastExpr( ret, addrExpr->result->clone() ); |
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310 | } |
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311 | return ret; |
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312 | } |
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313 | PRINT( std::cerr << "not current..." << std::endl; ) |
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314 | return addrExpr; |
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315 | } |
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316 | |
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317 | void AddrRef::premutate( ApplicationExpr * appExpr ) { |
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318 | visit_children = false; |
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319 | GuardValue( addCast ); |
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320 | handleNonAddr( appExpr ); |
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321 | for ( Expression *& arg : appExpr->args ) { |
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322 | // each argument with address-of requires a cast |
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323 | addCast = true; |
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324 | arg = arg->acceptMutator( *visitor ); |
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325 | } |
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326 | } |
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327 | |
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328 | void AddrRef::premutate( SingleInit * ) { |
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329 | GuardValue( addCast ); |
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330 | // each initialization context with address-of requires a cast |
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331 | addCast = true; |
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332 | } |
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333 | |
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334 | |
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335 | Expression * ReferenceConversions::postmutate( AddressExpr * addrExpr ) { |
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336 | // Inner expression may have been lvalue to reference conversion, which becomes an address expression. |
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337 | // In this case, remove the outer address expression and return the argument. |
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338 | // TODO: It's possible that this might catch too much and require a more sophisticated check. |
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339 | return addrExpr; |
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340 | } |
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341 | |
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342 | Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) { |
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343 | // xxx - is it possible to convert directly between reference types with a different base? E.g., |
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344 | // int x; |
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345 | // (double&)x; |
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346 | // At the moment, I am working off of the assumption that this is illegal, thus the cast becomes redundant |
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347 | // after this pass, so trash the cast altogether. If that changes, care must be taken to insert the correct |
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348 | // pointer casts in the right places. |
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349 | |
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350 | // Note: reference depth difference is the determining factor in what code is run, rather than whether something is |
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351 | // reference type or not, since conversion still needs to occur when both types are references that differ in depth. |
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352 | |
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353 | Type * destType = castExpr->result; |
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354 | Type * srcType = castExpr->arg->result; |
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355 | assertf( destType, "Cast to no type in: %s", toCString( castExpr ) ); |
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356 | assertf( srcType, "Cast from no type in: %s", toCString( castExpr ) ); |
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357 | int depth1 = destType->referenceDepth(); |
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358 | int depth2 = srcType->referenceDepth(); |
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359 | int diff = depth1 - depth2; |
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360 | |
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361 | if ( diff > 0 && ! srcType->get_lvalue() ) { |
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362 | // rvalue to reference conversion -- introduce temporary |
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363 | // know that reference depth of cast argument is 0, need to introduce n temporaries for reference depth of n, e.g. |
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364 | // (int &&&)3; |
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365 | // becomes |
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366 | // int __ref_tmp_0 = 3; |
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367 | // int & __ref_tmp_1 = _&_ref_tmp_0; |
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368 | // int && __ref_tmp_2 = &__ref_tmp_1; |
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369 | // &__ref_tmp_2; |
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370 | // the last & comes from the remaining reference conversion code |
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371 | SemanticWarning( castExpr->arg->location, Warning::RvalueToReferenceConversion, toCString( castExpr->arg ) ); |
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372 | |
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373 | static UniqueName tempNamer( "__ref_tmp_" ); |
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374 | ObjectDecl * temp = ObjectDecl::newObject( tempNamer.newName(), castExpr->arg->result->clone(), new SingleInit( castExpr->arg ) ); |
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375 | PRINT( std::cerr << "made temp: " << temp << std::endl; ) |
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376 | stmtsToAddBefore.push_back( new DeclStmt( temp ) ); |
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377 | for ( int i = 0; i < depth1-1; i++ ) { // xxx - maybe this should be diff-1? check how this works with reference type for srcType |
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378 | ObjectDecl * newTemp = ObjectDecl::newObject( tempNamer.newName(), new ReferenceType( Type::Qualifiers(), temp->type->clone() ), new SingleInit( new AddressExpr( new VariableExpr( temp ) ) ) ); |
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379 | PRINT( std::cerr << "made temp" << i << ": " << newTemp << std::endl; ) |
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380 | stmtsToAddBefore.push_back( new DeclStmt( newTemp ) ); |
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381 | temp = newTemp; |
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382 | } |
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383 | // update diff so that remaining code works out correctly |
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384 | castExpr->arg = new VariableExpr( temp ); |
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385 | PRINT( std::cerr << "update cast to: " << castExpr << std::endl; ) |
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386 | srcType = castExpr->arg->result; |
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387 | depth2 = srcType->referenceDepth(); |
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388 | diff = depth1 - depth2; |
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389 | assert( diff == 1 ); |
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390 | } |
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391 | |
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392 | // handle conversion between different depths |
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393 | PRINT ( |
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394 | if ( depth1 || depth2 ) { |
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395 | std::cerr << "destType: " << destType << " / srcType: " << srcType << std::endl; |
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396 | std::cerr << "depth: " << depth1 << " / " << depth2 << std::endl; |
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397 | } |
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398 | ) |
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399 | if ( diff > 0 ) { |
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400 | // conversion to type with more depth (e.g. int & -> int &&): add address-of for each level of difference |
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401 | Expression * ret = castExpr->arg; |
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402 | for ( int i = 0; i < diff; ++i ) { |
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403 | ret = new AddressExpr( ret ); |
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404 | } |
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405 | if ( srcType->get_lvalue() && ! ResolvExpr::typesCompatible( srcType, strict_dynamic_cast<ReferenceType *>( destType )->base, SymTab::Indexer() ) ) { |
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406 | // must keep cast if cast-to type is different from the actual type |
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407 | castExpr->arg = ret; |
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408 | return castExpr; |
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409 | } |
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410 | ret->env = castExpr->env; |
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411 | delete ret->result; |
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412 | ret->result = castExpr->result; |
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413 | castExpr->env = nullptr; |
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414 | castExpr->arg = nullptr; |
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415 | castExpr->result = nullptr; |
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416 | delete castExpr; |
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417 | return ret; |
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418 | } else if ( diff < 0 ) { |
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419 | // conversion to type with less depth (e.g. int && -> int &): add dereferences for each level of difference |
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420 | diff = -diff; // care only about magnitude now |
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421 | Expression * ret = castExpr->arg; |
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422 | for ( int i = 0; i < diff; ++i ) { |
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423 | ret = mkDeref( ret ); |
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424 | // xxx - try removing one reference here? actually, looks like mkDeref already does this, so more closely look at the types generated. |
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425 | } |
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426 | if ( ! ResolvExpr::typesCompatibleIgnoreQualifiers( destType->stripReferences(), srcType->stripReferences(), SymTab::Indexer() ) ) { |
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427 | // must keep cast if types are different |
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428 | castExpr->arg = ret; |
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429 | return castExpr; |
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430 | } |
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431 | ret->env = castExpr->env; |
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432 | delete ret->result; |
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433 | ret->result = castExpr->result; |
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434 | ret->result->set_lvalue( true ); // ensure result is lvalue |
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435 | castExpr->env = nullptr; |
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436 | castExpr->arg = nullptr; |
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437 | castExpr->result = nullptr; |
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438 | delete castExpr; |
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439 | return ret; |
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440 | } else { |
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441 | assert( diff == 0 ); |
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442 | // conversion between references of the same depth |
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443 | if ( ResolvExpr::typesCompatible( castExpr->result, castExpr->arg->result, SymTab::Indexer() ) && castExpr->isGenerated ) { |
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444 | // Remove useless generated casts |
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445 | PRINT( |
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446 | std::cerr << "types are compatible, removing cast: " << castExpr << std::endl; |
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447 | std::cerr << "-- " << castExpr->result << std::endl; |
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448 | std::cerr << "-- " << castExpr->arg->result << std::endl; |
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449 | ) |
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450 | Expression * ret = castExpr->arg; |
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451 | castExpr->arg = nullptr; |
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452 | std::swap( castExpr->env, ret->env ); |
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453 | delete castExpr; |
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454 | return ret; |
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455 | } |
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456 | return castExpr; |
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457 | } |
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458 | } |
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459 | |
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460 | Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) { |
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461 | Type * base = refType->base; |
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462 | Type::Qualifiers qualifiers = refType->get_qualifiers(); |
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463 | refType->base = nullptr; |
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464 | delete refType; |
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465 | return new PointerType( qualifiers, base ); |
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466 | } |
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467 | |
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468 | template<typename Func> |
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469 | Expression * GeneralizedLvalue::applyTransformation( Expression * expr, Expression * arg, Func mkExpr ) { |
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470 | if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( arg ) ) { |
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471 | Expression * arg1 = commaExpr->arg1->clone(); |
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472 | Expression * arg2 = commaExpr->arg2->clone(); |
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473 | Expression * ret = new CommaExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ) ); |
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474 | ret->env = expr->env; |
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475 | expr->env = nullptr; |
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476 | delete expr; |
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477 | return ret; |
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478 | } else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( arg ) ) { |
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479 | Expression * arg1 = condExpr->arg1->clone(); |
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480 | Expression * arg2 = condExpr->arg2->clone(); |
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481 | Expression * arg3 = condExpr->arg3->clone(); |
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482 | ConditionalExpr * ret = new ConditionalExpr( arg1, mkExpr( arg2 )->acceptMutator( *visitor ), mkExpr( arg3 )->acceptMutator( *visitor ) ); |
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483 | ret->env = expr->env; |
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484 | expr->env = nullptr; |
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485 | delete expr; |
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486 | |
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487 | // conditional expr type may not be either of the argument types, need to unify |
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488 | using namespace ResolvExpr; |
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489 | Type* commonType = nullptr; |
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490 | TypeEnvironment newEnv; |
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491 | AssertionSet needAssertions, haveAssertions; |
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492 | OpenVarSet openVars; |
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493 | unify( ret->arg2->result, ret->arg3->result, newEnv, needAssertions, haveAssertions, openVars, SymTab::Indexer(), commonType ); |
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494 | ret->result = commonType ? commonType : ret->arg2->result->clone(); |
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495 | return ret; |
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496 | } |
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497 | return expr; |
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498 | } |
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499 | |
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500 | Expression * GeneralizedLvalue::postmutate( MemberExpr * memExpr ) { |
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501 | return applyTransformation( memExpr, memExpr->aggregate, [=]( Expression * aggr ) { return new MemberExpr( memExpr->member, aggr ); } ); |
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502 | } |
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503 | |
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504 | Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) { |
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505 | return applyTransformation( addrExpr, addrExpr->arg, []( Expression * arg ) { return new AddressExpr( arg ); } ); |
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506 | } |
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507 | |
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508 | Expression * CollapseAddrDeref::postmutate( AddressExpr * addrExpr ) { |
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509 | Expression * arg = addrExpr->arg; |
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510 | if ( isIntrinsicReference( arg ) ) { |
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511 | std::string fname = InitTweak::getFunctionName( arg ); |
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512 | if ( fname == "*?" ) { |
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513 | Expression *& arg0 = InitTweak::getCallArg( arg, 0 ); |
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514 | Expression * ret = arg0; |
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515 | ret->set_env( addrExpr->env ); |
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516 | arg0 = nullptr; |
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517 | addrExpr->env = nullptr; |
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518 | delete addrExpr; |
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519 | return ret; |
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520 | } |
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521 | } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * > ( arg ) ) { |
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522 | // need to move cast to pointer type out a level since address of pointer |
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523 | // is not valid C code (can be introduced in prior passes, e.g., InstantiateGeneric) |
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524 | if ( InitTweak::getPointerBase( castExpr->result ) ) { |
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525 | addrExpr->arg = castExpr->arg; |
---|
526 | castExpr->arg = addrExpr; |
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527 | castExpr->result = new PointerType( Type::Qualifiers(), castExpr->result ); |
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528 | return castExpr; |
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529 | } |
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530 | } |
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531 | return addrExpr; |
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532 | } |
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533 | |
---|
534 | Expression * CollapseAddrDeref::postmutate( ApplicationExpr * appExpr ) { |
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535 | if ( isIntrinsicReference( appExpr ) ) { |
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536 | std::string fname = InitTweak::getFunctionName( appExpr ); |
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537 | if ( fname == "*?" ) { |
---|
538 | Expression * arg = InitTweak::getCallArg( appExpr, 0 ); |
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539 | // xxx - this isn't right, because it can remove casts that should be there... |
---|
540 | // while ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) { |
---|
541 | // arg = castExpr->get_arg(); |
---|
542 | // } |
---|
543 | if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( arg ) ) { |
---|
544 | Expression * ret = addrExpr->arg; |
---|
545 | ret->env = appExpr->env; |
---|
546 | addrExpr->arg = nullptr; |
---|
547 | appExpr->env = nullptr; |
---|
548 | delete appExpr; |
---|
549 | return ret; |
---|
550 | } |
---|
551 | } |
---|
552 | } |
---|
553 | return appExpr; |
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554 | } |
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555 | } // namespace |
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556 | } // namespace GenPoly |
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557 | |
---|
558 | // Local Variables: // |
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559 | // tab-width: 4 // |
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560 | // mode: c++ // |
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561 | // compile-command: "make install" // |
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562 | // End: // |
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