source: src/GenPoly/Lvalue.cc@ d36c117

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors deferred_resn demangler enum forall-pointer-decay jacob/cs343-translation jenkins-sandbox new-ast new-ast-unique-expr new-env no_list persistent-indexer pthread-emulation qualifiedEnum resolv-new with_gc
Last change on this file since d36c117 was ce8c12f, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

initial work on references: reference types passed through the system, very simple examples work
  • Property mode set to 100644
File size: 7.6 KB
Line 
1//
2// Cforall Version 1.0.0 Copyright (C) 2015 University of Waterloo
3//
4// The contents of this file are covered under the licence agreement in the
5// file "LICENCE" distributed with Cforall.
6//
7// Lvalue.cc --
8//
9// Author : Richard C. Bilson
10// Created On : Mon May 18 07:44:20 2015
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Fri Mar 17 09:11:18 2017
13// Update Count : 5
14//
15
16#include <cassert>
17
18#include "Lvalue.h"
19
20#include "GenPoly.h"
21
22#include "SynTree/Declaration.h"
23#include "SynTree/Type.h"
24#include "SynTree/Expression.h"
25#include "SynTree/Statement.h"
26#include "SynTree/Visitor.h"
27#include "SynTree/Mutator.h"
28#include "SymTab/Indexer.h"
29#include "ResolvExpr/Resolver.h"
30#include "ResolvExpr/typeops.h"
31
32#include "Common/UniqueName.h"
33#include "Common/utility.h"
34#include "InitTweak/InitTweak.h"
35
36namespace GenPoly {
37 namespace {
38 const std::list<Label> noLabels;
39
40 /// Replace uses of lvalue returns with appropriate pointers
41 class Pass1 : public Mutator {
42 public:
43 typedef Mutator Parent;
44 Pass1();
45
46 // xxx - should this happen to every expression with reference result type? probably just appexpr and varexpr?
47 virtual Type *mutate( ReferenceType * refType );
48 virtual Expression *mutate( VariableExpr *varExpr );
49 virtual Expression *mutate( ApplicationExpr *appExpr );
50 virtual Statement *mutate( ReturnStmt *appExpr );
51 virtual DeclarationWithType *mutate( FunctionDecl *funDecl );
52 private:
53 DeclarationWithType* retval;
54 };
55
56 /// Replace declarations of lvalue returns with appropriate pointers
57 class Pass2 : public Visitor {
58 public:
59 virtual void visit( FunctionType *funType );
60 private:
61 };
62
63 /// GCC-like Generalized Lvalues (which have since been removed from GCC)
64 /// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
65 /// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c)
66 class GeneralizedLvalue : public Mutator {
67 typedef Mutator Parent;
68
69 virtual Expression * mutate( AddressExpr * addressExpr );
70 };
71 } // namespace
72
73 void convertLvalue( std::list< Declaration* >& translationUnit ) {
74 Pass1 p1;
75 Pass2 p2;
76 GeneralizedLvalue genLval;
77 mutateAll( translationUnit, p1 );
78 acceptAll( translationUnit, p2 );
79 mutateAll( translationUnit, genLval );
80 }
81
82 namespace {
83 Type* isLvalueRet( FunctionType *function ) {
84 if ( function->get_returnVals().empty() ) return 0;
85 Type *ty = function->get_returnVals().front()->get_type();
86 return ty->get_lvalue() ? ty : 0;
87 }
88
89 bool isIntrinsicApp( ApplicationExpr *appExpr ) {
90 if ( VariableExpr *varExpr = dynamic_cast< VariableExpr* >( appExpr->get_function() ) ) {
91 return varExpr->get_var()->get_linkage() == LinkageSpec::Intrinsic;
92 } else {
93 return false;
94 } // if
95 }
96
97 Pass1::Pass1() {
98 }
99
100 DeclarationWithType * Pass1::mutate( FunctionDecl *funcDecl ) {
101 if ( funcDecl->get_statements() ) {
102 DeclarationWithType* oldRetval = retval;
103 retval = 0;
104 if ( ! LinkageSpec::isBuiltin( funcDecl->get_linkage() ) && isLvalueRet( funcDecl->get_functionType() ) ) {
105 retval = funcDecl->get_functionType()->get_returnVals().front();
106 }
107 // fix expressions and return statements in this function
108 funcDecl->set_statements( funcDecl->get_statements()->acceptMutator( *this ) );
109 retval = oldRetval;
110 } // if
111 return funcDecl;
112 }
113
114 Type * Pass1::mutate( ReferenceType * refType ) {
115 Type * base = refType->get_base();
116 refType->set_base( nullptr );
117 delete refType;
118 return new PointerType( Type::Qualifiers(), base );
119 }
120
121 Expression * Pass1::mutate( VariableExpr *varExpr ) {
122 if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( varExpr->get_result() ) ) {
123 varExpr->set_result( refType->acceptMutator( *this ) );
124 return UntypedExpr::createDeref( varExpr );
125 }
126 return Parent::mutate( varExpr );
127 }
128
129 Expression * Pass1::mutate( ApplicationExpr *appExpr ) {
130 appExpr->get_function()->acceptMutator( *this );
131 mutateAll( appExpr->get_args(), *this );
132
133 PointerType *pointer = safe_dynamic_cast< PointerType* >( appExpr->get_function()->get_result() );
134 FunctionType *function = safe_dynamic_cast< FunctionType* >( pointer->get_base() );
135
136 Type *funType = isLvalueRet( function );
137 if ( funType && ! isIntrinsicApp( appExpr ) ) {
138 Expression *expr = appExpr;
139 Type *appType = appExpr->get_result();
140 if ( isPolyType( funType ) && ! isPolyType( appType ) ) {
141 // make sure cast for polymorphic type is inside dereference
142 expr = new CastExpr( appExpr, new PointerType( Type::Qualifiers(), appType->clone() ) );
143 }
144 UntypedExpr *deref = new UntypedExpr( new NameExpr( "*?" ) );
145 deref->set_result( appType->clone() );
146 appExpr->set_result( new PointerType( Type::Qualifiers(), appType ) );
147 deref->get_args().push_back( expr );
148 return deref;
149 } else {
150 return appExpr;
151 } // if
152 }
153
154 Statement * Pass1::mutate(ReturnStmt *retStmt) {
155 if ( retval && retStmt->get_expr() ) {
156 if ( retStmt->get_expr()->get_result()->get_lvalue() ) {
157 // ***** Code Removal ***** because casts may be stripped already
158
159 // strip casts because not allowed to take address of cast
160 // while ( CastExpr *castExpr = dynamic_cast< CastExpr* >( retStmt->get_expr() ) ) {
161 // retStmt->set_expr( castExpr->get_arg() );
162 // retStmt->get_expr()->set_env( castExpr->get_env() );
163 // castExpr->set_env( 0 );
164 // castExpr->set_arg( 0 );
165 // delete castExpr;
166 // } // while
167 retStmt->set_expr( new AddressExpr( retStmt->get_expr()->acceptMutator( *this ) ) );
168 } else {
169 throw SemanticError( "Attempt to return non-lvalue from an lvalue-qualified function" );
170 } // if
171 } // if
172 return retStmt;
173 }
174
175 void Pass2::visit( FunctionType *funType ) {
176 std::string typeName;
177 if ( isLvalueRet( funType ) ) {
178 DeclarationWithType *retParm = funType->get_returnVals().front();
179
180 // make a new parameter that is a pointer to the type of the old return value
181 retParm->set_type( new PointerType( Type::Qualifiers(), retParm->get_type() ) );
182 } // if
183
184 Visitor::visit( funType );
185 }
186
187 bool isDeref( Expression * expr ) {
188 if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
189 return InitTweak::getFunctionName( untyped ) == "*?";
190 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
191 return InitTweak::getFunctionName( appExpr ) == "*?";
192 } else {
193 return false;
194 }
195 }
196
197 Expression * GeneralizedLvalue::mutate( AddressExpr * addrExpr ) {
198 addrExpr = safe_dynamic_cast< AddressExpr * >( Parent::mutate( addrExpr ) );
199 if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( addrExpr->get_arg() ) ) {
200 Expression * arg1 = commaExpr->get_arg1()->clone();
201 Expression * arg2 = commaExpr->get_arg2()->clone();
202 delete addrExpr;
203 return new CommaExpr( arg1, new AddressExpr( arg2 ) );
204 } else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( addrExpr->get_arg() ) ) {
205 Expression * arg1 = condExpr->get_arg1()->clone();
206 Expression * arg2 = condExpr->get_arg2()->clone();
207 Expression * arg3 = condExpr->get_arg3()->clone();
208 delete addrExpr;
209 return new ConditionalExpr( arg1, new AddressExpr( arg2 ), new AddressExpr( arg3 ) );
210 } else if ( isDeref( addrExpr->get_arg() ) ) {
211 // xxx - this doesn't belong here -- move it somewhere else
212 Expression *& arg = InitTweak::getCallArg( addrExpr->get_arg(), 0 );
213 Expression * inner = arg;
214 arg = nullptr;
215 delete addrExpr;
216 return inner;
217 }
218 return addrExpr;
219 }
220 } // namespace
221} // namespace GenPoly
222
223// Local Variables: //
224// tab-width: 4 //
225// mode: c++ //
226// compile-command: "make install" //
227// End: //
Note: See TracBrowser for help on using the repository browser.