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source: src/GenPoly/Lvalue.cc @ f19339e

ADTaaron-thesisarm-ehast-experimentalcleanup-dtorsdeferred_resndemanglerenumforall-pointer-decayjacob/cs343-translationjenkins-sandboxnew-astnew-ast-unique-exprnew-envno_listpersistent-indexerpthread-emulationqualifiedEnumresolv-newwith_gc

Last change on this file since f19339e was 1d776fd, checked in by Rob Schluntz <rschlunt@…>, 7 years ago
Implement reference conversion translation for basic reference conversions
Property mode set to `100644`
File size: 9.4 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
36	#include "Common/PassVisitor.h"
37
38	// need to be careful about polymorphic references... e.g. in *? (___operator_deref__A0_1_0_0__Fd0_Pd0_intrinsic___1)
39	// the variable is automatically dereferenced and this causes errors dereferencing void*.
40
41	namespace GenPoly {
42	namespace {
43	struct ReferenceConversions final {
44	Expression * postmutate( CastExpr * castExpr );
45	};
46
47	/// Intrinsic functions that take reference parameters don't REALLY take reference parameters -- their reference arguments must always be implicitly dereferenced.
48	struct FixIntrinsicArgs final {
49	Expression * postmutate( ApplicationExpr *appExpr );
50	};
51
52
53	/// Replace reference types with pointer types
54	struct ReferenceTypeElimination final {
55	Type * postmutate( ReferenceType * refType );
56	};
57
58	/// GCC-like Generalized Lvalues (which have since been removed from GCC)
59	/// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
60	/// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c)
61	struct GeneralizedLvalue final {
62	Expression * postmutate( AddressExpr * addressExpr );
63	};
64	} // namespace
65
66	void convertLvalue( std::list< Declaration* >& translationUnit ) {
67	std::cerr << "convertLvalue" << std::endl;
68	PassVisitor<ReferenceConversions> refCvt;
69	PassVisitor<ReferenceTypeElimination> elim;
70	PassVisitor<GeneralizedLvalue> genLval;
71	PassVisitor<FixIntrinsicArgs> fixer;
72	mutateAll( translationUnit, refCvt );
73	mutateAll( translationUnit, fixer );
74	mutateAll( translationUnit, elim );
75	mutateAll( translationUnit, genLval );
76	}
77
78	namespace {
79	Type* isLvalueRet( FunctionType *function ) {
80	if ( function->get_returnVals().empty() ) return 0;
81	Type *ty = function->get_returnVals().front()->get_type();
82	return dynamic_cast< ReferenceType * >( ty ) ;
83	}
84
85	bool isIntrinsicApp( ApplicationExpr *appExpr ) {
86	if ( VariableExpr varExpr = dynamic_cast< VariableExpr >( appExpr->get_function() ) ) {
87	return varExpr->get_var()->get_linkage() == LinkageSpec::Intrinsic;
88	} else {
89	return false;
90	} // if
91	}
92
93	bool isDeref( Expression * expr ) {
94	if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
95	return InitTweak::getFunctionName( untyped ) == "*?";
96	} else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
97	if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
98	return func->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getFunctionName( appExpr ) == "*?";
99	}
100	}
101	return false;
102	}
103
104	bool isIntrinsicReference( Expression * expr ) {
105	if ( isDeref( expr ) ) return true;
106	else if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * >( expr ) ) {
107	return InitTweak::getFunctionName( untyped ) == "?[?]";
108	} else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
109	if ( DeclarationWithType * func = InitTweak::getFunction( appExpr ) ) {
110	return func->get_linkage() == LinkageSpec::Intrinsic && InitTweak::getFunctionName( appExpr ) == "?[?]";
111	}
112	}
113	return false;
114	}
115
116	void fixArg( Expression & arg, Type formal ) {
117	// if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( arg ) ) {
118	if ( dynamic_cast<ReferenceType*>( formal ) ) { // xxx - but might be deref, in which case result isn't REALLY a reference, at least not in the sense that we need to add another deref...
119	// doesn't work, for some reason left arg is skipped in assign
120	ReferenceType * refType = safe_dynamic_cast< ReferenceType * >( arg->get_result() ) ;
121	std::cerr << "appexpr arg is non-deref/index intrinsic call" << std::endl;
122	std::cerr << arg << std::endl;
123	PointerType * ptrType = new PointerType( Type::Qualifiers(), refType->get_base()->clone() );
124	delete refType;
125	arg->set_result( ptrType );
126	arg = UntypedExpr::createDeref( arg );
127	}
128
129	// }
130	}
131
132	Expression * FixIntrinsicArgs::postmutate( ApplicationExpr * appExpr ) {
133	if ( DeclarationWithType * function = InitTweak::getFunction( appExpr ) ) {
134	if ( function->get_linkage() == LinkageSpec::Intrinsic ) { // intrinsic functions that turn pointers into references
135	FunctionType * ftype = GenPoly::getFunctionType( function->get_type() );
136	assertf( ftype, "Function declaration does not have function type." );
137	for ( auto p : group_iterate( appExpr->get_args(), ftype->get_parameters() ) ) {
138	Expression *& arg = std::get<0>( p );
139	DeclarationWithType * formal = std::get<1>( p );
140	std::cerr << "pair<0>: " << arg << std::endl;
141	std::cerr << "pair<1>: " << formal->get_type() << std::endl;
142	if ( isIntrinsicReference( arg ) ) {
143	std::cerr << "skipping intrinsic reference" << std::endl;
144	continue;
145	} else {
146	fixArg( arg, formal->get_type() );
147	}
148	}
149	}
150	}
151	return appExpr;
152	}
153
154	Expression * ReferenceConversions::postmutate( CastExpr * castExpr ) {
155	// conversion to reference type
156	if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( castExpr->get_result() ) ) {
157	(void)refType;
158	if ( ReferenceType * otherRef = dynamic_cast< ReferenceType * >( castExpr->get_arg()->get_result() ) ) {
159	// nothing to do if casting from reference to reference.
160	(void)otherRef;
161	std::cerr << "convert reference to reference -- nop" << std::endl;
162	if ( isIntrinsicReference( castExpr->get_arg() ) ) {
163	Expression * callExpr = castExpr->get_arg();
164	Expression ** arg = nullptr;
165	Expression *& arg0 = InitTweak::getCallArg( callExpr, 0 );
166	if ( dynamic_cast<PointerType *>( arg0->get_result() ) ) {
167	arg = &arg0;
168	} else {
169	arg = &InitTweak::getCallArg( callExpr, 1 );
170	}
171
172	castExpr->set_arg( *arg );
173	*arg = castExpr;
174	std::cerr << "but arg is deref -- &" << std::endl;
175	std::cerr << callExpr << std::endl;
176	// castExpr->set_arg( new AddressExpr( castExpr->get_arg() ) );
177
178	// move environment out to new top-level
179	callExpr->set_env( castExpr->get_env() );
180	castExpr->set_env( nullptr );
181	return callExpr;
182	}
183	std::cerr << castExpr << std::endl;
184	return castExpr;
185	} else if ( castExpr->get_arg()->get_result()->get_lvalue() ) {
186	// conversion from lvalue to reference
187	// xxx - keep cast, but turn into pointer cast??
188	// xxx - memory
189	std::cerr << "convert lvalue to reference -- &" << std::endl;
190	std::cerr << castExpr->get_arg() << std::endl;
191	castExpr->set_arg( new AddressExpr( castExpr->get_arg() ) );
192	// return new AddressExpr( castExpr->get_arg() );
193	return castExpr;
194	} else {
195	// rvalue to reference conversion -- introduce temporary
196	}
197	assertf( false, "Only conversions to reference from lvalue are currently supported: %s", toString( castExpr ).c_str() );
198	} else if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( castExpr->get_arg()->get_result() ) ) {
199	// should be easy, just need to move deref code up here?
200	std::cerr << "convert reference to rvalue -- *" << std::endl;
201	if ( isIntrinsicReference( castExpr->get_arg() ) ) {
202	std::cerr << "but arg is intrinsic reference -- nop" << std::endl;
203	return castExpr;
204	}
205	std::cerr << castExpr << std::endl;
206
207	PointerType * ptrType = new PointerType( refType->get_qualifiers(), refType->get_base()->clone() );
208	delete castExpr->get_result();
209	castExpr->set_result( ptrType );
210	Expression * deref = UntypedExpr::createDeref( castExpr );
211	deref->set_env( castExpr->get_env() );
212	castExpr->set_env( nullptr );
213	return deref;
214	// assertf( false, "Conversions from reference types are not currently supported." );
215	}
216	return castExpr;
217	}
218
219	Type * ReferenceTypeElimination::postmutate( ReferenceType * refType ) {
220	Type * base = refType->get_base();
221	refType->set_base( nullptr );
222	delete refType;
223	return new PointerType( Type::Qualifiers(), base );
224	}
225
226	Expression * GeneralizedLvalue::postmutate( AddressExpr * addrExpr ) {
227	if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( addrExpr->get_arg() ) ) {
228	Expression * arg1 = commaExpr->get_arg1()->clone();
229	Expression * arg2 = commaExpr->get_arg2()->clone();
230	delete addrExpr;
231	return new CommaExpr( arg1, new AddressExpr( arg2 ) );
232	} else if ( ConditionalExpr * condExpr = dynamic_cast< ConditionalExpr * >( addrExpr->get_arg() ) ) {
233	Expression * arg1 = condExpr->get_arg1()->clone();
234	Expression * arg2 = condExpr->get_arg2()->clone();
235	Expression * arg3 = condExpr->get_arg3()->clone();
236	delete addrExpr;
237	return new ConditionalExpr( arg1, new AddressExpr( arg2 ), new AddressExpr( arg3 ) );
238	}
239	return addrExpr;
240	}
241	} // namespace
242	} // namespace GenPoly
243
244	// Local Variables: //
245	// tab-width: 4 //
246	// mode: c++ //
247	// compile-command: "make install" //
248	// End: //

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