source: src/InitTweak/RemoveInit.cc@ 668edd6b

ADT aaron-thesis arm-eh ast-experimental cleanup-dtors ctor deferred_resn demangler enum forall-pointer-decay gc_noraii jacob/cs343-translation jenkins-sandbox memory 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 668edd6b was db4ecc5, checked in by Rob Schluntz <rschlunt@…>, 10 years ago

add ImplicitCopyCtorExpr node, implicit copy constructors are inserted into the right places (but there is room for elision)
  • Property mode set to 100644
File size: 10.8 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// RemoveInit.cc --
8//
9// Author : Rob Schluntz
10// Created On : Mon May 18 07:44:20 2015
11// Last Modified By : Rob Schluntz
12// Last Modified On : Thu Apr 14 15:09:36 2016
13// Update Count : 166
14//
15
16#include <stack>
17#include <list>
18#include "RemoveInit.h"
19#include "SynTree/Declaration.h"
20#include "SynTree/Type.h"
21#include "SynTree/Expression.h"
22#include "SynTree/Statement.h"
23#include "SynTree/Initializer.h"
24#include "SynTree/Mutator.h"
25#include "SymTab/Autogen.h"
26#include "GenPoly/PolyMutator.h"
27
28namespace InitTweak {
29 namespace {
30 const std::list<Label> noLabels;
31 const std::list<Expression *> noDesignators;
32 }
33
34 class RemoveInit : public GenPoly::PolyMutator {
35 public:
36 /// removes and replaces initialization for polymorphic value objects
37 /// with assignment (TODO: constructor) statements.
38 /// also consistently allocates a temporary variable for the return value
39 /// of a function so that anything which the resolver decides can be assigned
40 /// into the return type of a function can be returned.
41 static void removeInitializers( std::list< Declaration * > &translationUnit );
42
43 RemoveInit();
44
45 virtual ObjectDecl * mutate( ObjectDecl *objDecl );
46 virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );
47
48 virtual Statement * mutate( ReturnStmt * returnStmt );
49
50 protected:
51 std::list<DeclarationWithType*> returnVals;
52 UniqueName tempNamer;
53 std::string funcName;
54 };
55
56 class CtorDtor : public GenPoly::PolyMutator {
57 public:
58 /// create constructor and destructor statements for object declarations.
59 /// Destructors are inserted directly into the code, whereas constructors
60 /// will be added in after the resolver has run so that the initializer expression
61 /// is only removed if a constructor is found
62 static void generateCtorDtor( std::list< Declaration * > &translationUnit );
63
64 CtorDtor() : inFunction( false ) {}
65
66 virtual DeclarationWithType * mutate( ObjectDecl * );
67 virtual DeclarationWithType * mutate( FunctionDecl *functionDecl );
68 virtual Declaration* mutate( StructDecl *aggregateDecl );
69 virtual Declaration* mutate( UnionDecl *aggregateDecl );
70 virtual Declaration* mutate( EnumDecl *aggregateDecl );
71 virtual Declaration* mutate( TraitDecl *aggregateDecl );
72 virtual TypeDecl* mutate( TypeDecl *typeDecl );
73 virtual Declaration* mutate( TypedefDecl *typeDecl );
74
75 virtual Type * mutate( FunctionType *funcType );
76
77 protected:
78 bool inFunction;
79 };
80
81 void tweak( std::list< Declaration * > & translationUnit ) {
82 RemoveInit::removeInitializers( translationUnit );
83 CtorDtor::generateCtorDtor( translationUnit );
84 }
85
86 void RemoveInit::removeInitializers( std::list< Declaration * > & translationUnit ) {
87 RemoveInit remover;
88 mutateAll( translationUnit, remover );
89 }
90
91 RemoveInit::RemoveInit() : tempNamer( "_retVal" ) {}
92
93 // in the case where an object has an initializer and a polymorphic type, insert an assignment immediately after the
94 // declaration. This will (seemingly) cause the later phases to do the right thing with the assignment
95 ObjectDecl *RemoveInit::mutate( ObjectDecl *objDecl ) {
96 if (objDecl->get_init() && dynamic_cast<TypeInstType*>(objDecl->get_type())) {
97 if (SingleInit * single = dynamic_cast<SingleInit*>(objDecl->get_init())) {
98 // xxx this can be more complicated - consider ListInit
99 UntypedExpr *assign = new UntypedExpr( new NameExpr( "?{}" ) );
100 assign->get_args().push_back( new AddressExpr( new VariableExpr( objDecl ) ) );
101 assign->get_args().push_back( single->get_value()->clone() );
102 stmtsToAddAfter.push_back(new ExprStmt(noLabels, assign));
103 } // if
104 } // if
105 return objDecl;
106 }
107
108 Statement *RemoveInit::mutate( ReturnStmt *returnStmt ) {
109 // update for multiple return values
110 assert( returnVals.size() == 0 || returnVals.size() == 1 );
111 // hands off if the function returns an lvalue - we don't want to allocate a temporary if a variable's address
112 // is being returned
113 if ( returnStmt->get_expr() && returnVals.size() == 1 && funcName != "?=?" && ! returnVals.front()->get_type()->get_isLvalue() ) {
114 // ensure return value is not destructed by explicitly creating
115 // an empty SingleInit node wherein maybeConstruct is false
116 ObjectDecl *newObj = new ObjectDecl( tempNamer.newName(), DeclarationNode::NoStorageClass, LinkageSpec::C, 0, returnVals.front()->get_type()->clone(), new ListInit( std::list<Initializer*>(), noDesignators, false ) );
117 stmtsToAdd.push_back( new DeclStmt( noLabels, newObj ) );
118
119 // and explicitly create the constructor expression separately
120 UntypedExpr *construct = new UntypedExpr( new NameExpr( "?{}" ) );
121 construct->get_args().push_back( new AddressExpr( new VariableExpr( newObj ) ) );
122 construct->get_args().push_back( returnStmt->get_expr() );
123 stmtsToAdd.push_back(new ExprStmt(noLabels, construct));
124
125 returnStmt->set_expr( new VariableExpr( newObj ) );
126 } // if
127 return returnStmt;
128 }
129
130 DeclarationWithType* RemoveInit::mutate( FunctionDecl *functionDecl ) {
131 std::list<DeclarationWithType*> oldReturnVals = returnVals;
132 std::string oldFuncName = funcName;
133
134 FunctionType * type = functionDecl->get_functionType();
135 returnVals = type->get_returnVals();
136 funcName = functionDecl->get_name();
137 DeclarationWithType * decl = Mutator::mutate( functionDecl );
138 returnVals = oldReturnVals;
139 funcName = oldFuncName;
140 return decl;
141 }
142
143
144 void CtorDtor::generateCtorDtor( std::list< Declaration * > & translationUnit ) {
145 CtorDtor ctordtor;
146 mutateAll( translationUnit, ctordtor );
147 }
148
149 namespace {
150 bool tryConstruct( ObjectDecl * objDecl ) {
151 // xxx - handle designations
152 return ! LinkageSpec::isBuiltin( objDecl->get_linkage() ) &&
153 (objDecl->get_init() == NULL ||
154 ( objDecl->get_init() != NULL && objDecl->get_init()->get_maybeConstructed() ));
155 }
156
157 Expression * makeCtorDtorExpr( std::string name, ObjectDecl * objDecl, std::list< Expression * > args ) {
158 UntypedExpr * expr = new UntypedExpr( new NameExpr( name ) );
159 expr->get_args().push_back( new AddressExpr( new VariableExpr( objDecl ) ) );
160 expr->get_args().splice( expr->get_args().end(), args );
161 return expr;
162 }
163
164 class InitExpander : public Visitor {
165 public:
166 InitExpander() {}
167 // ~InitExpander() {}
168 virtual void visit( SingleInit * singleInit );
169 virtual void visit( ListInit * listInit );
170 std::list< Expression * > argList;
171 };
172
173 void InitExpander::visit( SingleInit * singleInit ) {
174 argList.push_back( singleInit->get_value()->clone() );
175 }
176
177 void InitExpander::visit( ListInit * listInit ) {
178 // xxx - for now, assume no nested list inits
179 std::list<Initializer*>::iterator it = listInit->begin_initializers();
180 for ( ; it != listInit->end_initializers(); ++it ) {
181 (*it)->accept( *this );
182 }
183 }
184
185 std::list< Expression * > makeInitList( Initializer * init ) {
186 InitExpander expander;
187 maybeAccept( init, expander );
188 return expander.argList;
189 }
190 }
191
192 DeclarationWithType * CtorDtor::mutate( ObjectDecl * objDecl ) {
193 // hands off if designated or if @=
194 if ( tryConstruct( objDecl ) ) {
195 if ( inFunction ) {
196 if ( ArrayType * at = dynamic_cast< ArrayType * >( objDecl->get_type() ) ) {
197 // call into makeArrayFunction from validate.cc to generate calls to ctor/dtor for each element of array
198 // TODO: walk initializer and generate appropriate copy ctor if element has initializer
199 std::list< Statement * > ctor;
200 std::list< Statement * > dtor;
201
202 SymTab::makeArrayFunction( NULL, new VariableExpr( objDecl ), at, "?{}", back_inserter( ctor ) );
203 SymTab::makeArrayFunction( NULL, new VariableExpr( objDecl ), at, "^?{}", front_inserter( dtor ), false );
204
205 // Currently makeArrayFunction produces a single Statement - a CompoundStmt
206 // which wraps everything that needs to happen. As such, it's technically
207 // possible to use a Statement ** in the above calls, but this is inherently
208 // unsafe, so instead we take the slightly less efficient route, but will be
209 // immediately informed if somehow the above assumption is broken. In this case,
210 // we could always wrap the list of statements at this point with a CompoundStmt,
211 // but it seems reasonable at the moment for this to be done by makeArrayFunction
212 // itself
213 assert( ctor.size() == 1 );
214 assert( dtor.size() == 1 );
215
216 objDecl->set_init( new ConstructorInit( ctor.front(), dtor.front(), objDecl->get_init() ) );
217 } else {
218 // it's sufficient to attempt to call the ctor/dtor for the given object and its initializer
219 Expression * ctor = makeCtorDtorExpr( "?{}", objDecl, makeInitList( objDecl->get_init() ) );
220 Expression * dtor = makeCtorDtorExpr( "^?{}", objDecl, std::list< Expression * >() );
221
222 // need to remember init expression, in case no ctors exist
223 // if ctor does exist, want to use ctor expression instead of init
224 // push this decision to the resolver
225 ExprStmt * ctorStmt = new ExprStmt( noLabels, ctor );
226 ExprStmt * dtorStmt = new ExprStmt( noLabels, dtor );
227 objDecl->set_init( new ConstructorInit( ctorStmt, dtorStmt, objDecl->get_init() ) );
228 }
229 } else {
230 // xxx - find a way to construct/destruct globals
231 // hack: implicit "static" initialization routine for each struct type? or something similar?
232 // --ties into module system
233 // this can be done by mangling main and replacing it with our own main which calls each
234 // module initialization routine in some decided order (order given in link command?)
235 // and finally calls mangled main
236 }
237 }
238 return Mutator::mutate( objDecl );
239 }
240
241 DeclarationWithType * CtorDtor::mutate( FunctionDecl *functionDecl ) {
242 // parameters should not be constructed and destructed, so don't mutate FunctionType
243 bool oldInFunc = inFunction;
244 mutateAll( functionDecl->get_oldDecls(), *this );
245 inFunction = true;
246 functionDecl->set_statements( maybeMutate( functionDecl->get_statements(), *this ) );
247 inFunction = oldInFunc;
248 return functionDecl;
249 }
250
251 // should not traverse into any of these declarations to find objects
252 // that need to be constructed or destructed
253 Declaration* CtorDtor::mutate( StructDecl *aggregateDecl ) { return aggregateDecl; }
254 Declaration* CtorDtor::mutate( UnionDecl *aggregateDecl ) { return aggregateDecl; }
255 Declaration* CtorDtor::mutate( EnumDecl *aggregateDecl ) { return aggregateDecl; }
256 Declaration* CtorDtor::mutate( TraitDecl *aggregateDecl ) { return aggregateDecl; }
257 TypeDecl* CtorDtor::mutate( TypeDecl *typeDecl ) { return typeDecl; }
258 Declaration* CtorDtor::mutate( TypedefDecl *typeDecl ) { return typeDecl; }
259 Type* CtorDtor::mutate( FunctionType *funcType ) { return funcType; }
260
261} // namespace InitTweak
262
263// Local Variables: //
264// tab-width: 4 //
265// mode: c++ //
266// compile-command: "make install" //
267// End: //
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