[7fffb1b] | 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 | // LvalueNew.cpp -- Clean up lvalues and remove references.
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| 8 | //
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| 9 | // Author : Andrew Beach
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| 10 | // Created On : Thu Sep 15 14:08:00 2022
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| 11 | // Last Modified By : Andrew Beach
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| 12 | // Last Modified On : Wed Oct 6 9:59:00 2022
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| 13 | // Update Count : 0
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| 14 | //
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| 15 |
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| 16 | #include "Lvalue.h"
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| 17 |
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| 18 | #include <set>
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| 19 | #include <iostream>
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| 20 |
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| 21 | #include "AST/Copy.hpp" // for deepCopy
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| 22 | #include "AST/Expr.hpp"
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| 23 | #include "AST/Inspect.hpp"
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| 24 | #include "AST/LinkageSpec.hpp" // for Linkage
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| 25 | #include "AST/Pass.hpp"
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| 26 | #include "Common/SemanticError.h" // for SemanticWarning
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| 27 | #include "Common/UniqueName.h" // for UniqueName
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| 28 | #include "GenPoly/GenPoly.h" // for genFunctionType
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| 29 | #include "ResolvExpr/typeops.h" // for typesCompatible
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| 30 | #include "ResolvExpr/Unify.h" // for unify
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| 31 |
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| 32 | #if 0
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| 33 | #define PRINT(x) x
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| 34 | #else
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| 35 | #define PRINT(x)
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| 36 | #endif
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| 37 |
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| 38 | namespace GenPoly {
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| 39 |
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| 40 | namespace {
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| 41 |
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| 42 | /// Intrinsic functions that return references now instead return lvalues.
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| 43 | struct FixIntrinsicResults final : public ast::WithGuards {
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| 44 | enum {
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| 45 | NoSkip,
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| 46 | Skip,
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| 47 | SkipInProgress,
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| 48 | } skip = NoSkip;
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| 49 |
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| 50 | void previsit( ast::AsmExpr const * ) {
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| 51 | GuardValue( skip ) = Skip;
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| 52 | }
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| 53 | void previsit( ast::ApplicationExpr const * ) {
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| 54 | GuardValue( skip ) = (skip == Skip) ? SkipInProgress : NoSkip;
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| 55 | }
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| 56 |
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| 57 | ast::Expr const * postvisit( ast::ApplicationExpr const * expr );
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| 58 | void previsit( ast::FunctionDecl const * decl );
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| 59 | bool inIntrinsic = false;
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| 60 | };
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| 61 |
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| 62 | /// Add de-references around address-of operations on reference types.
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| 63 | struct AddressRef final :
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| 64 | public ast::WithConstTranslationUnit,
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| 65 | public ast::WithGuards,
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| 66 | public ast::WithShortCircuiting,
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| 67 | public ast::WithVisitorRef<AddressRef> {
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| 68 | void previsit( ast::AddressExpr const * expr );
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| 69 | ast::Expr const * postvisit( ast::AddressExpr const * expr );
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| 70 | void previsit( ast::Expr const * expr );
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| 71 | ast::ApplicationExpr const * previsit( ast::ApplicationExpr const * expr );
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| 72 | void previsit( ast::SingleInit const * init );
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| 73 |
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| 74 | void handleNonAddr( ast::Expr const * expr );
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| 75 |
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| 76 | bool first = true;
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| 77 | bool current = false;
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| 78 | bool addCast = false;
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| 79 | int refDepth = 0;
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| 80 | };
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| 81 |
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| 82 | /// Handles casts between references and pointers,
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| 83 | /// creating temporaries for the conversion.
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| 84 | struct ReferenceConversions final :
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| 85 | public ast::WithConstTranslationUnit,
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| 86 | public ast::WithGuards, public ast::WithStmtsToAdd<> {
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| 87 | ast::Expr const * postvisit( ast::CastExpr const * expr );
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| 88 | ast::Expr const * postvisit( ast::AddressExpr const * expr );
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| 89 | };
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| 90 |
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| 91 | /// Intrinsic functions that take reference parameters don't actually do.
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| 92 | /// Their reference arguments must be implicity dereferenced.
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| 93 | /// TODO Also appears to contain redundent code with AddressRef
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| 94 | struct FixIntrinsicArgs final :
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| 95 | public ast::WithConstTranslationUnit {
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| 96 | ast::Expr const * postvisit( ast::ApplicationExpr const * expr );
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| 97 | };
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| 98 |
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| 99 | /// Removes redundant &* / *& patterns that may be generated.
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| 100 | struct CollapseAddressDeref final {
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| 101 | ast::Expr const * postvisit( ast::AddressExpr const * expr );
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| 102 | ast::Expr const * postvisit( ast::ApplicationExpr const * expr );
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| 103 | };
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| 104 |
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| 105 | /// GCC-like Generalized Lvalues (which have since been removed from GCC).
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| 106 | /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
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| 107 | /// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c)
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| 108 | struct GeneralizedLvalue final :
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| 109 | public ast::WithVisitorRef<GeneralizedLvalue> {
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| 110 | ast::Expr const * postvisit( ast::AddressExpr const * expr );
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| 111 | ast::Expr const * postvisit( ast::MemberExpr const * expr );
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| 112 |
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| 113 | template<typename Node, typename Func>
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| 114 | ast::Expr const * applyTransformation(
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| 115 | Node const * expr, ast::ptr<ast::Expr> Node::*field, Func mkExpr );
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| 116 | };
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| 117 |
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| 118 | /// Replace all reference types with pointer types.
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| 119 | struct ReferenceTypeElimination final {
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| 120 | ast::Type const * postvisit( ast::ReferenceType const * type );
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| 121 | };
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| 122 |
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| 123 | /// True for intrinsic function calls that return an lvalue in C.
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| 124 | bool isIntrinsicReference( ast::Expr const * expr ) {
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| 125 | // The known intrinsic-reference prelude functions.
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| 126 | static std::set<std::string> const lvalueFunctions = { "*?", "?[?]" };
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| 127 | if ( auto untyped = dynamic_cast<ast::UntypedExpr const *>( expr ) ) {
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| 128 | std::string fname = ast::getFunctionName( untyped );
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| 129 | return lvalueFunctions.count( fname );
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| 130 | } else if ( auto app = dynamic_cast<ast::ApplicationExpr const *>( expr ) ) {
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| 131 | if ( auto func = ast::getFunction( app ) ) {
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| 132 | return func->linkage == ast::Linkage::Intrinsic
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| 133 | && lvalueFunctions.count( func->name );
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| 134 | }
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| 135 | }
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| 136 | return false;
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| 137 | }
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| 138 |
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| 139 | // A maybe typed variant of the createDeref function (only UntypedExpr).
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| 140 | ast::Expr * mkDeref(
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| 141 | ast::TranslationGlobal const & global, ast::Expr const * arg ) {
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| 142 | if ( global.dereference ) {
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| 143 | // Note: Reference depth can be arbitrarily deep here,
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| 144 | // so peel off the outermost pointer/reference, not just
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| 145 | // pointer because they are effecitvely equivalent in this pass
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| 146 | ast::VariableExpr * deref = new ast::VariableExpr(
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| 147 | arg->location, global.dereference );
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| 148 | deref->result = new ast::PointerType( deref->result );
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| 149 | ast::Type const * base = ast::getPointerBase( arg->result );
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| 150 | assertf( base, "expected pointer type in dereference (type was %s)", toString( arg->result ).c_str() );
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| 151 | ast::ApplicationExpr * ret =
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| 152 | new ast::ApplicationExpr( arg->location, deref, { arg } );
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| 153 | ret->result = ast::deepCopy( base );
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| 154 | return ret;
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| 155 | } else {
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| 156 | return ast::UntypedExpr::createDeref( arg->location, arg );
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| 157 | }
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| 158 | }
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| 159 |
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| 160 | ast::Expr const * FixIntrinsicResults::postvisit(
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| 161 | ast::ApplicationExpr const * expr ) {
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| 162 | if ( skip == SkipInProgress || !isIntrinsicReference( expr ) ) {
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| 163 | return expr;
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| 164 | }
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| 165 | // Eliminate reference types from intrinsic applications
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| 166 | // now they return lvalues.
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| 167 | ast::ptr<ast::ReferenceType> result =
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| 168 | expr->result.strict_as<ast::ReferenceType>();
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| 169 | expr = ast::mutate_field( expr, &ast::ApplicationExpr::result,
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| 170 | ast::deepCopy( result->base ) );
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| 171 | if ( inIntrinsic ) {
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| 172 | return expr;
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| 173 | }
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| 174 | // When not in an intrinsic function, add a cast to don't add cast when
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| 175 | // in an intrinsic function, since they already have the cast.
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| 176 | auto * ret = new ast::CastExpr( expr->location, expr, result.get() );
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| 177 | ret->env = expr->env;
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| 178 | return ret;
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| 179 | }
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| 180 |
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| 181 | void FixIntrinsicResults::previsit( ast::FunctionDecl const * decl ) {
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| 182 | GuardValue( inIntrinsic ) = decl->linkage == ast::Linkage::Intrinsic;
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| 183 | }
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| 184 |
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| 185 | void AddressRef::previsit( ast::AddressExpr const * ) {
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| 186 | // Is this the first address-of in the chain?
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| 187 | GuardValue( current ) = first;
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| 188 | // Later references will not be for next address-of to be first in chain.
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| 189 | GuardValue( first ) = false;
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| 190 | // If is the outermost address-of in a chain:
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| 191 | if ( current ) {
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| 192 | // Set depth to 0 so that postvisit can
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| 193 | // find the innermost address-of easily.
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| 194 | GuardValue( refDepth ) = 0;
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| 195 | }
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| 196 | }
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| 197 |
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| 198 | ast::Expr const * AddressRef::postvisit( ast::AddressExpr const * expr ) {
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| 199 | PRINT( std::cerr << "addr ref at " << expr << std::endl; )
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| 200 | if ( 0 == refDepth ) {
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| 201 | PRINT( std::cerr << "depth 0, get new depth..." << std::endl; )
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| 202 | // Is this the innermost address-of in a chain? record depth D.
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| 203 | if ( isIntrinsicReference( expr->arg ) ) {
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| 204 | assertf( false, "AddrRef : address-of should not have intrinsic reference argument: %s", toCString( expr->arg ) );
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| 205 | } else {
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| 206 | // try to avoid ?[?]
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| 207 | // TODO is this condition still necessary? intrinsicReferences
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| 208 | // should have a cast around them at this point, so I don't think
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| 209 | // this condition ever fires.
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| 210 | refDepth = expr->arg->result->referenceDepth();
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| 211 | PRINT( std::cerr << "arg not intrinsic reference, new depth is: " << refDepth << std::endl; )
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| 212 | }
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| 213 | }
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| 214 | if ( current ) {
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| 215 | PRINT( std::cerr << "current, depth is: " << refDepth << std::endl; )
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| 216 | ast::Expr const * ret = expr;
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| 217 | while ( refDepth ) {
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| 218 | // Add one dereference for each address-of in the chain.
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| 219 | ret = mkDeref( transUnit().global, ret );
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| 220 | --refDepth;
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| 221 | }
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| 222 |
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| 223 | // if addrExpr depth is 0, then the result is a pointer because the
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| 224 | // arg was depth 1 and not lvalue. This means the dereference result
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| 225 | // is not a reference, is lvalue, and one less pointer depth than the
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| 226 | // addrExpr. Thus the cast is meaningless.
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| 227 | // TODO: One thing to double check is whether it is possible for the
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| 228 | // types to differ outside of the single pointer level (i.e. can the
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| 229 | // base type of addrExpr differ from the type of addrExpr-arg?). If
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| 230 | // so then the cast might need to be added, conditional on a more
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| 231 | // sophisticated check.
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| 232 | if ( addCast && 0 != expr->result->referenceDepth() ) {
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| 233 | PRINT( std::cerr << "adding cast to " << expr->result << std::endl; )
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| 234 | return new ast::CastExpr( expr->location,
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| 235 | ret, ast::deepCopy( expr->result ) );
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| 236 | }
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| 237 | return ret;
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| 238 | }
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| 239 | PRINT( std::cerr << "not current..." << std::endl; )
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| 240 | return expr;
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| 241 | }
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| 242 |
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| 243 | void AddressRef::previsit( ast::Expr const * expr ) {
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| 244 | handleNonAddr( expr );
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| 245 | GuardValue( addCast ) = false;
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| 246 | }
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| 247 |
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| 248 | // So we want to skip traversing to the head?
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| 249 | ast::ApplicationExpr const * AddressRef::previsit(
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| 250 | ast::ApplicationExpr const * expr ) {
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| 251 | visit_children = false;
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| 252 | GuardValue( addCast );
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| 253 | handleNonAddr( expr );
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| 254 | auto mutExpr = ast::mutate( expr );
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| 255 | for ( ast::ptr<ast::Expr> & arg : mutExpr->args ) {
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| 256 | addCast = true;
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| 257 | arg = arg->accept( *visitor );
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| 258 | }
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| 259 | return mutExpr;
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| 260 | }
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| 261 |
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| 262 | void AddressRef::previsit( ast::SingleInit const * ) {
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| 263 | // Each initialization context with address-of requires a cast.
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| 264 | GuardValue( addCast ) = true;
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| 265 | }
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| 266 |
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| 267 | // idea: &&&E: get outer &, inner &
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| 268 | // at inner &, record depth D of reference type of argument of &.
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| 269 | // at auter &, add D derefs.
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| 270 | void AddressRef::handleNonAddr( ast::Expr const * ) {
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| 271 | // non-address-of: reset status variables:
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| 272 | // * current expr is NOT the first address-of expr in an address-of chain.
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| 273 | // * next seen address-of expr IS the first in the chain.
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| 274 | GuardValue( current ) = false;
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| 275 | GuardValue( first ) = true;
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| 276 | }
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| 277 |
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| 278 | ast::Expr const * ReferenceConversions::postvisit(
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| 279 | ast::CastExpr const * expr ) {
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| 280 | // TODO: Is it possible to convert directly between reference types with
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| 281 | // a different base. e.g.
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| 282 | // int x;
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| 283 | // (double&)x;
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| 284 | // At the moment, I (who?) am working off of the assumption that this is
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| 285 | // illegal, thus the cast becomes redundant after this pass, so trash the
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| 286 | // cast altogether. If that changes, care must be taken to insert the
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| 287 | // correct pointer casts in the right places.
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| 288 |
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| 289 | // Note: reference depth difference is the determining factor in what
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| 290 | // code is run, rather than whether something is reference type or not,
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| 291 | // since conversion still needs to occur when both types are references
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| 292 | // that differ in depth.
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| 293 | ast::Type const * dstType = expr->result.get();
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| 294 | ast::Type const * srcType = expr->arg->result.get();
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| 295 | assertf( dstType, "Cast to no type in: %s", toCString( expr ) );
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| 296 | assertf( srcType, "Cast from no type in: %s", toCString( expr ) );
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| 297 | int dstDepth = dstType->referenceDepth();
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| 298 | int srcDepth = srcType->referenceDepth();
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| 299 | int diff = dstDepth - srcDepth;
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| 300 |
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| 301 | if ( 0 < diff && !expr->arg->get_lvalue() ) {
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| 302 | // rvalue to reference conversion -- introduce temporary
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| 303 | // know that reference depth of cast argument is 0
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| 304 | // (int &&&)3;
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| 305 | // becomes
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| 306 | // int __ref_tmp_0 = 3;
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| 307 | // int & __ref_tmp_1 = &__ref_tmp_0;
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| 308 | // int && __ref_tmp_2 = &__ref_tmp_1;
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| 309 | // &__ref_tmp_2;
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| 310 | // The last & comes from the remaining reference conversion code.
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| 311 | SemanticWarning( expr->arg->location,
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| 312 | Warning::RvalueToReferenceConversion, toCString( expr->arg ) );
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| 313 |
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| 314 | static UniqueName tmpNamer( "__ref_tmp_" );
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| 315 | ast::ObjectDecl * tmp = new ast::ObjectDecl( expr->arg->location,
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| 316 | tmpNamer.newName(),
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| 317 | ast::deepCopy( expr->arg->result ),
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| 318 | new ast::SingleInit( expr->arg->location, expr->arg ) );
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| 319 | PRINT( std::cerr << "make tmp: " << tmp << std::endl; )
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| 320 | stmtsToAddBefore.push_back( new ast::DeclStmt( tmp->location, tmp ) );
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| 321 | for ( int i = 0 ; i < dstDepth - 1 ; ++i ) {
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| 322 | ast::ObjectDecl * newTmp = new ast::ObjectDecl( tmp->location,
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| 323 | tmpNamer.newName(),
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| 324 | new ast::ReferenceType( ast::deepCopy( tmp->type ) ),
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| 325 | new ast::SingleInit( tmp->location,
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| 326 | new ast::AddressExpr( tmp->location,
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| 327 | new ast::VariableExpr( tmp->location, tmp ) ) ) );
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| 328 | PRINT( std::cerr << "make tmp: " << i << ": " << newTmp << std::endl; )
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| 329 | stmtsToAddBefore.push_back(
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| 330 | new ast::DeclStmt( newTmp->location, newTmp ) );
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| 331 | tmp = newTmp;
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| 332 | }
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| 333 | // Update diff so that remaining code works out correctly.
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| 334 | expr = ast::mutate_field( expr, &ast::CastExpr::arg,
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| 335 | new ast::VariableExpr( tmp->location, tmp ) );
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| 336 | PRINT( std::cerr << "update cast to: " << expr << std::endl; )
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| 337 | srcType = expr->arg->result;
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| 338 | srcDepth = srcType->referenceDepth();
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| 339 | diff = dstDepth - srcDepth;
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| 340 | assert( 1 == diff );
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| 341 | }
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| 342 |
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| 343 | // Handle conversion between different depths.
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| 344 | PRINT(
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| 345 | if ( dstDepth || srcDepth ) {
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| 346 | std::cerr << "dstType: " << dstType << " / srcType: " << srcType << '\n';
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| 347 | std::cerr << "depth: " << dstDepth << " / " << srcDepth << std::endl;
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| 348 | }
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| 349 | )
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| 350 | // Conversion to type with more depth/more references.
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| 351 | // Add address-of for each level of difference.
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| 352 | if ( 0 < diff ) {
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| 353 | ast::Expr * ret = ast::mutate( expr->arg.get() );
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| 354 | for ( int i = 0 ; i < diff ; ++i ) {
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| 355 | ret = new ast::AddressExpr( ret->location, ret );
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| 356 | }
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| 357 | if ( expr->arg->get_lvalue() &&
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| 358 | !ResolvExpr::typesCompatible(
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| 359 | srcType,
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| 360 | strict_dynamic_cast<ast::ReferenceType const *>( dstType )->base,
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| 361 | ast::SymbolTable() ) ) {
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| 362 | // Must keep cast if cast-to type is different from the actual type.
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| 363 | return ast::mutate_field( expr, &ast::CastExpr::arg, ret );
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| 364 | }
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| 365 | ret->env = expr->env;
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| 366 | ret->result = expr->result;
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| 367 | return ret;
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| 368 | // Conversion to type with less depth/fewer references.
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| 369 | // Add dereferences for each level of difference.
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| 370 | } else if ( diff < 0 ) {
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| 371 | ast::Expr * ret = ast::mutate( expr->arg.get() );
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| 372 | for ( int i = 0 ; i < -diff ; ++i ) {
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| 373 | ret = mkDeref( transUnit().global, ret );
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| 374 | }
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| 375 | // Must keep cast if types are different.
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| 376 | if ( !ResolvExpr::typesCompatibleIgnoreQualifiers(
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| 377 | dstType->stripReferences(),
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| 378 | srcType->stripReferences(),
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| 379 | ast::SymbolTable() ) ) {
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| 380 | return ast::mutate_field( expr, &ast::CastExpr::arg, ret );
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| 381 | }
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| 382 | ret->env = expr->env;
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| 383 | ret->result = expr->result;
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| 384 | // The result must be an lvalue.
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| 385 | assert( ret->get_lvalue() );
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| 386 | return ret;
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| 387 | // Conversion with the same depth.
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| 388 | } else {
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| 389 | assert( 0 == diff );
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| 390 | // Remove useless generated casts.
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| 391 | if ( expr->isGenerated &&
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| 392 | ResolvExpr::typesCompatible(
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| 393 | expr->result,
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| 394 | expr->arg->result, ast::SymbolTable() ) ) {
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| 395 | PRINT(
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| 396 | std::cerr << "types are compatible, removing cast: " << expr << '\n';
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| 397 | std::cerr << "-- " << expr->result << '\n';
|
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| 398 | std::cerr << "-- " << expr->arg->result << std::endl;
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| 399 | )
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| 400 | return ast::mutate_field( expr->arg.get(),
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| 401 | &ast::Expr::env, expr->env.get() );
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| 402 | }
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| 403 | return expr;
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| 404 | }
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| 405 | }
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| 406 |
|
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| 407 | ast::Expr const * ReferenceConversions::postvisit(
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| 408 | ast::AddressExpr const * expr ) {
|
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| 409 | // Inner expression may have been lvalue to reference conversion, which
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| 410 | // becomes an address expression. In this case, remove the outer address
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| 411 | // expression and return the argument.
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| 412 | // TODO: It's possible that this might catch too much and require a more
|
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| 413 | // sophisticated check. TODO What check are we talking about here?
|
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| 414 | return expr;
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| 415 | }
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| 416 |
|
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| 417 | ast::Expr const * FixIntrinsicArgs::postvisit(
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| 418 | ast::ApplicationExpr const * expr ) {
|
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| 419 | // Intrinsic functions don't really take reference-typed parameters,
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| 420 | // so they require an implicit dereference on their arguments.
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| 421 | auto function = ast::getFunction( expr );
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| 422 | if ( function == nullptr ) {
|
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| 423 | return expr;
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| 424 | }
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| 425 |
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| 426 | ast::FunctionType const * ftype = GenPoly::getFunctionType( function->get_type() );
|
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| 427 | assertf( ftype, "Function declaration does not have function type." );
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| 428 | // Can be of different lengths only when function is variadic.
|
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| 429 | assertf( ftype->params.size() == expr->args.size() || ftype->isVarArgs,
|
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| 430 | "ApplicationExpr args do not match formal parameter type." );
|
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| 431 | assertf( ftype->params.size() <= expr->args.size(),
|
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| 432 | "Cannot have more parameters than arguments." );
|
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| 433 |
|
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| 434 | unsigned int i = 0;
|
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| 435 | unsigned int const end = ftype->params.size();
|
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| 436 |
|
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| 437 | // This is used to make sure we get a zip on shortests.
|
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| 438 | if ( end == i ) return expr;
|
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| 439 |
|
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| 440 | // This mutate could be redundent, but it is simpler this way.
|
---|
| 441 | auto mutExpr = ast::mutate( expr );
|
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| 442 |
|
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| 443 | for ( auto pair : unsafe_group_iterate( mutExpr->args, ftype->params ) ) {
|
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| 444 | ast::ptr<ast::Expr> & arg = std::get<0>( pair );
|
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| 445 | ast::ptr<ast::Type> const & formal = std::get<1>( pair );
|
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| 446 | PRINT(
|
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| 447 | std::cerr << "pair<0>: " << arg.get() << std::endl;
|
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| 448 | std::cerr << " -- " << arg->result << std::endl;
|
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| 449 | std::cerr << "pair<1>: " << formal << std::endl;
|
---|
| 450 | )
|
---|
| 451 | //if ( dynamic_cast<ast::ReferenceType const *>( formal.get() ) ) {
|
---|
| 452 | if ( formal.as<ast::ReferenceType>() ) {
|
---|
| 453 | PRINT( std::cerr << "===formal is reference" << std::endl; )
|
---|
| 454 | // TODO: It's likely that the second condition should be
|
---|
| 455 | // `... && ! isIntrinsicReference( arg )`, but this requires
|
---|
| 456 | // investigation.
|
---|
| 457 |
|
---|
| 458 | if ( ast::Linkage::Intrinsic != function->linkage
|
---|
| 459 | && isIntrinsicReference( arg ) ) {
|
---|
| 460 | // Needed for definition of prelude functions, etc.
|
---|
| 461 | // If argument is dereference or array subscript, the result
|
---|
| 462 | // isn't REALLY a reference, but non-intrinsic functions
|
---|
| 463 | // expect a reference: take address
|
---|
| 464 |
|
---|
| 465 | // TODO: OK, so this should be cut?!
|
---|
| 466 | // NODE: Previously, this condition fixed
|
---|
| 467 | // void f(int *&);
|
---|
| 468 | // int & x = ...;
|
---|
| 469 | // f(&x);
|
---|
| 470 | // But now this is taken care of by a reference cast added by
|
---|
| 471 | // AddressRef. Need to find a new example or remove this
|
---|
| 472 | // branch.
|
---|
| 473 | PRINT(
|
---|
| 474 | std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl;
|
---|
| 475 | )
|
---|
| 476 | arg = new ast::AddressExpr( arg->location, arg );
|
---|
| 477 | } else if ( ast::Linkage::Intrinsic == function->linkage
|
---|
| 478 | && arg->result->referenceDepth() != 0 ) {
|
---|
| 479 | // Argument is a 'real' reference, but function expects a C
|
---|
| 480 | // lvalue: Add a dereference to the reference-typed argument.
|
---|
| 481 | PRINT(
|
---|
| 482 | std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl;
|
---|
| 483 | )
|
---|
| 484 | ast::Type const * base = ast::getPointerBase( arg->result );
|
---|
| 485 | assertf( base, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() );
|
---|
| 486 | ast::PointerType * ptr = new ast::PointerType( ast::deepCopy( base ) );
|
---|
| 487 | arg = ast::mutate_field( arg.get(),
|
---|
| 488 | &ast::ApplicationExpr::result, ptr );
|
---|
| 489 | arg = mkDeref( transUnit().global, arg );
|
---|
| 490 | }
|
---|
| 491 | }
|
---|
| 492 | ++i;
|
---|
| 493 | if ( end == i ) break;
|
---|
| 494 | }
|
---|
| 495 | return mutExpr;
|
---|
| 496 | }
|
---|
| 497 |
|
---|
| 498 | ast::Expr const * CollapseAddressDeref::postvisit(
|
---|
| 499 | ast::AddressExpr const * expr ) {
|
---|
| 500 | ast::Expr const * arg = expr->arg;
|
---|
| 501 | if ( isIntrinsicReference( arg ) ) {
|
---|
| 502 | std::string fname = ast::getFunctionName( arg );
|
---|
| 503 | if ( fname == "*?" ) {
|
---|
| 504 | ast::Expr const * arg0 = ast::getCallArg( arg, 0 );
|
---|
| 505 | ast::Expr * ret = ast::mutate( arg0 );
|
---|
| 506 | ret->env = expr->env;
|
---|
| 507 | return ret;
|
---|
| 508 | }
|
---|
| 509 | } else if ( auto cast = dynamic_cast<ast::CastExpr const *>( arg ) ) {
|
---|
| 510 | // Need to move cast to pointer type out a level since address of
|
---|
| 511 | // pointer is not valid C code (can be introduced in prior passes,
|
---|
| 512 | // e.g., InstantiateGeneric)
|
---|
| 513 | if ( ast::getPointerBase( cast->result ) ) {
|
---|
| 514 | auto mutExpr = ast::mutate( expr );
|
---|
| 515 | auto mutCast = strict_dynamic_cast<ast::CastExpr *>(
|
---|
| 516 | ast::mutate( mutExpr->arg.release() ) );
|
---|
| 517 | mutExpr->arg = mutCast->arg;
|
---|
| 518 | mutCast->arg = mutExpr;
|
---|
| 519 | mutCast->result = new ast::PointerType( mutCast->result );
|
---|
| 520 | return mutCast;
|
---|
| 521 | }
|
---|
| 522 | }
|
---|
| 523 | return expr;
|
---|
| 524 | }
|
---|
| 525 |
|
---|
| 526 | ast::Expr const * CollapseAddressDeref::postvisit(
|
---|
| 527 | ast::ApplicationExpr const * expr ) {
|
---|
| 528 | if ( isIntrinsicReference( expr ) ) {
|
---|
| 529 | std::string fname = ast::getFunctionName( expr );
|
---|
| 530 | if ( fname == "*?" ) {
|
---|
| 531 | assert( 1 == expr->args.size() );
|
---|
| 532 | ast::Expr const * arg = ast::getCallArg( expr, 0 );
|
---|
| 533 | // xxx - this isn't right, because it can remove casts that
|
---|
| 534 | // should be there...
|
---|
| 535 | // while ( auto cast = dynamic_cast< ast::CastExpr const * >( arg ) ) {
|
---|
| 536 | // arg = cast->arg;
|
---|
| 537 | // }
|
---|
| 538 | if ( auto addr = dynamic_cast<ast::AddressExpr const *>( arg ) ) {
|
---|
| 539 | return ast::mutate_field( addr->arg.get(),
|
---|
| 540 | &ast::Expr::env, expr->env.get() );
|
---|
| 541 | }
|
---|
| 542 | }
|
---|
| 543 | }
|
---|
| 544 | return expr;
|
---|
| 545 | }
|
---|
| 546 |
|
---|
| 547 | ast::Expr const * GeneralizedLvalue::postvisit(
|
---|
| 548 | ast::AddressExpr const * expr ) {
|
---|
| 549 | return applyTransformation( expr, &ast::AddressExpr::arg,
|
---|
| 550 | []( ast::Expr const * arg ) {
|
---|
| 551 | return new ast::AddressExpr( arg->location, arg );
|
---|
| 552 | }
|
---|
| 553 | );
|
---|
| 554 | }
|
---|
| 555 |
|
---|
| 556 | ast::Expr const * GeneralizedLvalue::postvisit(
|
---|
| 557 | ast::MemberExpr const * expr ) {
|
---|
| 558 | return applyTransformation( expr, &ast::MemberExpr::aggregate,
|
---|
| 559 | [expr]( ast::Expr const * aggr ) {
|
---|
| 560 | return new ast::MemberExpr( aggr->location, expr->member, aggr );
|
---|
| 561 | }
|
---|
| 562 | );
|
---|
| 563 | }
|
---|
| 564 |
|
---|
| 565 | template<typename Node, typename Func>
|
---|
| 566 | ast::Expr const * GeneralizedLvalue::applyTransformation(
|
---|
| 567 | Node const * expr, ast::ptr<ast::Expr> Node::*field, Func mkExpr ) {
|
---|
| 568 | ast::ptr<ast::Expr> const & arg = expr->*field;
|
---|
| 569 | if ( auto commaArg = arg.as<ast::CommaExpr>() ) {
|
---|
| 570 | ast::Expr const * arg1 = ast::deepCopy( commaArg->arg1 );
|
---|
| 571 | ast::Expr const * arg2 = ast::deepCopy( commaArg->arg2 );
|
---|
| 572 | ast::Expr const * ret = new ast::CommaExpr(
|
---|
| 573 | commaArg->location, arg1, mkExpr( arg2 )->accept( *visitor ) );
|
---|
| 574 | return ret;
|
---|
| 575 | } else if ( auto condArg = arg.as<ast::ConditionalExpr>() ) {
|
---|
| 576 | ast::Expr const * arg1 = ast::deepCopy( condArg->arg1 );
|
---|
| 577 | ast::Expr const * arg2 = ast::deepCopy( condArg->arg2 );
|
---|
| 578 | ast::Expr const * arg3 = ast::deepCopy( condArg->arg3 );
|
---|
| 579 | ast::ConditionalExpr * ret = new ast::ConditionalExpr(
|
---|
| 580 | condArg->location, arg1, mkExpr( arg2 )->accept( *visitor ),
|
---|
| 581 | mkExpr( arg3 )->accept( *visitor ) );
|
---|
| 582 |
|
---|
| 583 | // Conditional expr type may not be either of the arguments,
|
---|
| 584 | // so unify to get the result.
|
---|
| 585 | // TODO: Maybe I could create a wrapper for this.
|
---|
| 586 | ast::ptr<ast::Type> common = nullptr;
|
---|
| 587 | ast::TypeEnvironment newEnv;
|
---|
| 588 | ast::AssertionSet needAssertions, haveAssertions;
|
---|
| 589 | ast::OpenVarSet openVars;
|
---|
| 590 | ResolvExpr::unify( ret->arg2->result, ret->arg3->result, newEnv,
|
---|
| 591 | needAssertions, haveAssertions, openVars,
|
---|
| 592 | ast::SymbolTable(), common );
|
---|
| 593 | ret->result = common ? common : ast::deepCopy( ret->arg2->result );
|
---|
| 594 | return ret;
|
---|
| 595 | }
|
---|
| 596 | return expr;
|
---|
| 597 | }
|
---|
| 598 |
|
---|
| 599 | ast::Type const * ReferenceTypeElimination::postvisit(
|
---|
| 600 | ast::ReferenceType const * type ) {
|
---|
| 601 | return new ast::PointerType( type->base, type->qualifiers );
|
---|
| 602 | }
|
---|
| 603 |
|
---|
| 604 | } // namespace
|
---|
| 605 |
|
---|
| 606 | // Stored elsewhere (Lvalue2, initially false):
|
---|
| 607 | extern bool referencesEliminated;
|
---|
| 608 |
|
---|
| 609 | void convertLvalue( ast::TranslationUnit & translationUnit ) {
|
---|
| 610 | ast::Pass<FixIntrinsicResults>::run( translationUnit );
|
---|
| 611 | ast::Pass<AddressRef>::run( translationUnit );
|
---|
| 612 | ast::Pass<ReferenceConversions>::run( translationUnit );
|
---|
| 613 | ast::Pass<FixIntrinsicArgs>::run( translationUnit );
|
---|
| 614 | ast::Pass<CollapseAddressDeref>::run( translationUnit );
|
---|
| 615 | ast::Pass<GeneralizedLvalue>::run( translationUnit );
|
---|
| 616 | // Last because other passes need reference types to work.
|
---|
| 617 | ast::Pass<ReferenceTypeElimination>::run( translationUnit );
|
---|
| 618 | // From this point forward, nothing should create reference types.
|
---|
| 619 | referencesEliminated = true;
|
---|
| 620 | }
|
---|
| 621 |
|
---|
| 622 | ast::Expr const * generalizedLvalue( ast::Expr const * expr ) {
|
---|
| 623 | ast::Pass<GeneralizedLvalue> visitor;
|
---|
| 624 | return expr->accept( visitor );
|
---|
| 625 | }
|
---|
| 626 |
|
---|
| 627 | } // namespace GenPoly
|
---|
| 628 |
|
---|
| 629 | // Local Variables: //
|
---|
| 630 | // tab-width: 4 //
|
---|
| 631 | // mode: c++ //
|
---|
| 632 | // compile-command: "make install" //
|
---|
| 633 | // End: //
|
---|