source: src/InitTweak/FixInit.cc@ 65dc863

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 65dc863 was e9a3b20b, checked in by Peter A. Buhr <pabuhr@…>, 8 years ago

Merge branch 'master' of plg2:software/cfa/cfa-cc
  • Property mode set to 100644
File size: 52.4 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// FixInit.h --
8//
9// Author : Rob Schluntz
10// Created On : Wed Jan 13 16:29:30 2016
11// Last Modified By : Peter A. Buhr
12// Last Modified On : Wed Jun 21 17:35:05 2017
13// Update Count : 74
14//
15
16#include <stack>
17#include <list>
18#include <iterator>
19#include <algorithm>
20#include <unordered_map>
21#include <unordered_set>
22
23#include "InitTweak.h"
24#include "GenInit.h"
25#include "FixInit.h"
26#include "FixGlobalInit.h"
27#include "CodeGen/GenType.h" // for warning/error messages
28#include "Common/PassVisitor.h"
29#include "GenPoly/DeclMutator.h"
30#include "GenPoly/PolyMutator.h"
31#include "ResolvExpr/Resolver.h"
32#include "ResolvExpr/typeops.h"
33#include "SymTab/Autogen.h"
34#include "SymTab/Indexer.h"
35#include "SynTree/AddStmtVisitor.h"
36#include "SynTree/Attribute.h"
37#include "SynTree/Declaration.h"
38#include "SynTree/Expression.h"
39#include "SynTree/Initializer.h"
40#include "SynTree/Mutator.h"
41#include "SynTree/Statement.h"
42#include "SynTree/Type.h"
43#include "Tuples/Tuples.h"
44
45bool ctordtorp = false; // print all debug
46bool ctorp = false; // print ctor debug
47bool cpctorp = false; // print copy ctor debug
48bool dtorp = false; // print dtor debug
49#define PRINT( text ) if ( ctordtorp ) { text }
50#define CP_CTOR_PRINT( text ) if ( ctordtorp || cpctorp ) { text }
51#define DTOR_PRINT( text ) if ( ctordtorp || dtorp ) { text }
52
53namespace InitTweak {
54 namespace {
55 typedef std::unordered_map< Expression *, TypeSubstitution * > EnvMap;
56 typedef std::unordered_map< int, int > UnqCount;
57
58 class InsertImplicitCalls : public WithTypeSubstitution {
59 public:
60 /// wrap function application expressions as ImplicitCopyCtorExpr nodes so that it is easy to identify which
61 /// function calls need their parameters to be copy constructed
62 static void insert( std::list< Declaration * > & translationUnit, EnvMap & envMap );
63
64 InsertImplicitCalls( EnvMap & envMap ) : envMap( envMap ) {}
65
66 Expression * postmutate( ApplicationExpr * appExpr );
67 void premutate( StmtExpr * stmtExpr );
68
69 // collects environments for relevant nodes
70 EnvMap & envMap;
71 };
72
73 class ResolveCopyCtors final : public SymTab::Indexer {
74 public:
75 /// generate temporary ObjectDecls for each argument and return value of each ImplicitCopyCtorExpr,
76 /// generate/resolve copy construction expressions for each, and generate/resolve destructors for both
77 /// arguments and return value temporaries
78 static void resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap, UnqCount & unqCount );
79
80 typedef SymTab::Indexer Parent;
81 using Parent::visit;
82
83 ResolveCopyCtors( const EnvMap & envMap, UnqCount & unqCount ) : envMap( envMap ), unqCount( unqCount ) {}
84
85 virtual void visit( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
86 virtual void visit( UniqueExpr * unqExpr ) override;
87 virtual void visit( StmtExpr * stmtExpr ) override;
88
89 /// create and resolve ctor/dtor expression: fname(var, [cpArg])
90 Expression * makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg = NULL );
91 /// true if type does not need to be copy constructed to ensure correctness
92 bool skipCopyConstruct( Type * type );
93 void copyConstructArg( Expression *& arg, ImplicitCopyCtorExpr * impCpCtorExpr );
94 void destructRet( ObjectDecl * ret, ImplicitCopyCtorExpr * impCpCtorExpr );
95
96 TypeSubstitution * env;
97 const EnvMap & envMap;
98 UnqCount & unqCount; // count the number of times each unique expr ID appears
99 };
100
101 /// collects constructed object decls - used as a base class
102 class ObjDeclCollector : public AddStmtVisitor {
103 public:
104 typedef AddStmtVisitor Parent;
105 using Parent::visit;
106 typedef std::set< ObjectDecl * > ObjectSet;
107 virtual void visit( CompoundStmt *compoundStmt ) override;
108 virtual void visit( DeclStmt *stmt ) override;
109
110 // don't go into other functions
111 virtual void visit( __attribute__((unused)) FunctionDecl *decl ) override {}
112
113 protected:
114 ObjectSet curVars;
115 };
116
117 // debug
118 struct printSet {
119 typedef ObjDeclCollector::ObjectSet ObjectSet;
120 printSet( const ObjectSet & objs ) : objs( objs ) {}
121 const ObjectSet & objs;
122 };
123 std::ostream & operator<<( std::ostream & out, const printSet & set) {
124 out << "{ ";
125 for ( ObjectDecl * obj : set.objs ) {
126 out << obj->get_name() << ", " ;
127 } // for
128 out << " }";
129 return out;
130 }
131
132 class LabelFinder final : public ObjDeclCollector {
133 public:
134 typedef ObjDeclCollector Parent;
135 typedef std::map< Label, ObjectSet > LabelMap;
136 // map of Label -> live variables at that label
137 LabelMap vars;
138
139 void handleStmt( Statement * stmt );
140
141 // xxx - This needs to be done better.
142 // allow some generalization among different kinds of nodes with with similar parentage (e.g. all
143 // expressions, all statements, etc.) important to have this to provide a single entry point so that as new
144 // subclasses are added, there is only one place that the code has to be updated, rather than ensure that
145 // every specialized class knows about every new kind of statement that might be added.
146 using Parent::visit;
147 virtual void visit( CompoundStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
148 virtual void visit( ExprStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
149 virtual void visit( AsmStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
150 virtual void visit( IfStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
151 virtual void visit( WhileStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
152 virtual void visit( ForStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
153 virtual void visit( SwitchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
154 virtual void visit( CaseStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
155 virtual void visit( BranchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
156 virtual void visit( ReturnStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
157 virtual void visit( TryStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
158 virtual void visit( CatchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
159 virtual void visit( FinallyStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
160 virtual void visit( NullStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
161 virtual void visit( DeclStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
162 virtual void visit( ImplicitCtorDtorStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
163 };
164
165 class InsertDtors final : public ObjDeclCollector {
166 public:
167 /// insert destructor calls at the appropriate places. must happen before CtorInit nodes are removed
168 /// (currently by FixInit)
169 static void insert( std::list< Declaration * > & translationUnit );
170
171 typedef ObjDeclCollector Parent;
172 typedef std::list< ObjectDecl * > OrderedDecls;
173 typedef std::list< OrderedDecls > OrderedDeclsStack;
174
175 InsertDtors( LabelFinder & finder ) : finder( finder ), labelVars( finder.vars ) {}
176
177 using Parent::visit;
178
179 virtual void visit( ObjectDecl * objDecl ) override;
180 virtual void visit( FunctionDecl * funcDecl ) override;
181
182 virtual void visit( CompoundStmt * compoundStmt ) override;
183 virtual void visit( ReturnStmt * returnStmt ) override;
184 virtual void visit( BranchStmt * stmt ) override;
185 private:
186 void handleGoto( BranchStmt * stmt );
187
188 LabelFinder & finder;
189 LabelFinder::LabelMap & labelVars;
190 OrderedDeclsStack reverseDeclOrder;
191 };
192
193 class FixInit : public WithStmtsToAdd {
194 public:
195 /// expand each object declaration to use its constructor after it is declared.
196 static void fixInitializers( std::list< Declaration * > &translationUnit );
197
198 DeclarationWithType * postmutate( ObjectDecl *objDecl );
199
200 std::list< Declaration * > staticDtorDecls;
201 };
202
203 class FixCopyCtors final : public GenPoly::PolyMutator {
204 public:
205 FixCopyCtors( UnqCount & unqCount ) : unqCount( unqCount ){}
206 /// expand ImplicitCopyCtorExpr nodes into the temporary declarations, copy constructors, call expression,
207 /// and destructors
208 static void fixCopyCtors( std::list< Declaration * > &translationUnit, UnqCount & unqCount );
209
210 typedef GenPoly::PolyMutator Parent;
211 using Parent::mutate;
212 virtual Expression * mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
213 virtual Expression * mutate( UniqueExpr * unqExpr ) override;
214 virtual Expression * mutate( StmtExpr * stmtExpr ) override;
215
216 UnqCount & unqCount;
217 };
218
219 class GenStructMemberCalls final : public SymTab::Indexer {
220 public:
221 typedef Indexer Parent;
222 /// generate default/copy ctor and dtor calls for user-defined struct ctor/dtors
223 /// for any member that is missing a corresponding ctor/dtor call.
224 /// error if a member is used before constructed
225 static void generate( std::list< Declaration * > & translationUnit );
226
227 using Parent::visit;
228
229 virtual void visit( FunctionDecl * funcDecl ) override;
230
231 virtual void visit( MemberExpr * memberExpr ) override;
232 virtual void visit( ApplicationExpr * appExpr ) override;
233
234 SemanticError errors;
235 private:
236 void handleFirstParam( Expression * firstParam );
237 template< typename... Params >
238 void emit( CodeLocation, const Params &... params );
239
240 FunctionDecl * function = 0;
241 std::set< DeclarationWithType * > unhandled;
242 std::map< DeclarationWithType *, CodeLocation > usedUninit;
243 ObjectDecl * thisParam = 0;
244 bool isCtor = false; // true if current function is a constructor
245 StructDecl * structDecl = 0;
246 };
247
248 // very simple resolver-like mutator class - used to
249 // resolve UntypedExprs that are found within newly
250 // generated constructor/destructor calls
251 class MutatingResolver final : public Mutator {
252 public:
253 MutatingResolver( SymTab::Indexer & indexer ) : indexer( indexer ) {}
254
255 using Mutator::mutate;
256 virtual DeclarationWithType* mutate( ObjectDecl *objectDecl ) override;
257 virtual Expression* mutate( UntypedExpr *untypedExpr ) override;
258
259 private:
260 SymTab::Indexer & indexer;
261 };
262
263 class FixCtorExprs final : public GenPoly::DeclMutator {
264 public:
265 /// expands ConstructorExpr nodes into comma expressions, using a temporary for the first argument
266 static void fix( std::list< Declaration * > & translationUnit );
267
268 using GenPoly::DeclMutator::mutate;
269 virtual Expression * mutate( ConstructorExpr * ctorExpr ) override;
270 };
271 } // namespace
272
273 void fix( std::list< Declaration * > & translationUnit, const std::string & filename, bool inLibrary ) {
274 // fixes ConstructorInit for global variables. should happen before fixInitializers.
275 InitTweak::fixGlobalInit( translationUnit, filename, inLibrary );
276
277 EnvMap envMap;
278 UnqCount unqCount;
279
280 InsertImplicitCalls::insert( translationUnit, envMap );
281 ResolveCopyCtors::resolveImplicitCalls( translationUnit, envMap, unqCount );
282 InsertDtors::insert( translationUnit );
283 FixInit::fixInitializers( translationUnit );
284
285 // FixCopyCtors must happen after FixInit, so that destructors are placed correctly
286 FixCopyCtors::fixCopyCtors( translationUnit, unqCount );
287
288 GenStructMemberCalls::generate( translationUnit );
289 // xxx - ctor expansion currently has to be after FixCopyCtors, because there is currently a
290 // hack in the way untyped assignments are generated, where the first argument cannot have
291 // its address taken because of the way codegeneration handles UntypedExpr vs. ApplicationExpr.
292 // Thus such assignment exprs must never pushed through expression resolution (and thus should
293 // not go through the FixCopyCtors pass), otherwise they will fail -- guaranteed.
294 // Also needs to happen after GenStructMemberCalls, since otherwise member constructors exprs
295 // don't look right, and a member can be constructed more than once.
296 FixCtorExprs::fix( translationUnit );
297 }
298
299 namespace {
300 void InsertImplicitCalls::insert( std::list< Declaration * > & translationUnit, EnvMap & envMap ) {
301 PassVisitor<InsertImplicitCalls> inserter( envMap );
302 mutateAll( translationUnit, inserter );
303 }
304
305 void ResolveCopyCtors::resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap, UnqCount & unqCount ) {
306 ResolveCopyCtors resolver( envMap, unqCount );
307 acceptAll( translationUnit, resolver );
308 }
309
310 void FixInit::fixInitializers( std::list< Declaration * > & translationUnit ) {
311 PassVisitor<FixInit> fixer;
312
313 // can't use mutateAll, because need to insert declarations at top-level
314 // can't use DeclMutator, because sometimes need to insert IfStmt, etc.
315 SemanticError errors;
316 for ( std::list< Declaration * >::iterator i = translationUnit.begin(); i != translationUnit.end(); ++i ) {
317 try {
318 *i = maybeMutate( *i, fixer );
319 translationUnit.splice( i, fixer.pass.staticDtorDecls );
320 } catch( SemanticError &e ) {
321 e.set_location( (*i)->location );
322 errors.append( e );
323 } // try
324 } // for
325 if ( ! errors.isEmpty() ) {
326 throw errors;
327 } // if
328 }
329
330 void InsertDtors::insert( std::list< Declaration * > & translationUnit ) {
331 LabelFinder finder;
332 InsertDtors inserter( finder );
333 acceptAll( translationUnit, inserter );
334 }
335
336 void FixCopyCtors::fixCopyCtors( std::list< Declaration * > & translationUnit, UnqCount & unqCount ) {
337 FixCopyCtors fixer( unqCount );
338 mutateAll( translationUnit, fixer );
339 }
340
341 void GenStructMemberCalls::generate( std::list< Declaration * > & translationUnit ) {
342 GenStructMemberCalls warner;
343 acceptAll( translationUnit, warner );
344 }
345
346 void FixCtorExprs::fix( std::list< Declaration * > & translationUnit ) {
347 FixCtorExprs fixer;
348 fixer.mutateDeclarationList( translationUnit );
349 }
350
351 Expression * InsertImplicitCalls::postmutate( ApplicationExpr * appExpr ) {
352 assert( appExpr );
353
354 if ( VariableExpr * function = dynamic_cast< VariableExpr * > ( appExpr->get_function() ) ) {
355 if ( LinkageSpec::isBuiltin( function->get_var()->get_linkage() ) ) {
356 // optimization: don't need to copy construct in order to call intrinsic functions
357 return appExpr;
358 } else if ( DeclarationWithType * funcDecl = dynamic_cast< DeclarationWithType * > ( function->get_var() ) ) {
359 FunctionType * ftype = dynamic_cast< FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) );
360 assert( ftype );
361 if ( isConstructor( funcDecl->get_name() ) && ftype->get_parameters().size() == 2 ) {
362 Type * t1 = ftype->get_parameters().front()->get_type();
363 Type * t2 = ftype->get_parameters().back()->get_type();
364 PointerType * ptrType = safe_dynamic_cast< PointerType * > ( t1 );
365
366 if ( ResolvExpr::typesCompatible( ptrType->get_base(), t2, SymTab::Indexer() ) ) {
367 // optimization: don't need to copy construct in order to call a copy constructor
368 return appExpr;
369 } // if
370 } else if ( isDestructor( funcDecl->get_name() ) ) {
371 // correctness: never copy construct arguments to a destructor
372 return appExpr;
373 } // if
374 } // if
375 } // if
376 CP_CTOR_PRINT( std::cerr << "InsertImplicitCalls: adding a wrapper " << appExpr << std::endl; )
377
378 // wrap each function call so that it is easy to identify nodes that have to be copy constructed
379 ImplicitCopyCtorExpr * expr = new ImplicitCopyCtorExpr( appExpr );
380 // save the type substitution into the envMap so that it is easy to find.
381 // Ensure it is not deleted with the ImplicitCopyCtorExpr by removing it before deletion.
382 // The substitution is needed to obtain the type of temporary variables so that copy constructor
383 // calls can be resolved. Normally this is what PolyMutator is for, but the pass that resolves
384 // copy constructor calls must be an Indexer. We could alternatively make a PolyIndexer which
385 // saves the environment, or compute the types of temporaries here, but it's much simpler to
386 // save the environment here, and more cohesive to compute temporary variables and resolve copy
387 // constructor calls together.
388 assert( env );
389 envMap[expr] = env;
390 return expr;
391 }
392
393 void InsertImplicitCalls::premutate( StmtExpr * stmtExpr ) {
394 assert( env );
395 envMap[stmtExpr] = env;
396 }
397
398 bool ResolveCopyCtors::skipCopyConstruct( Type * type ) {
399 return dynamic_cast< VarArgsType * >( type ) || GenPoly::getFunctionType( type ) || Tuples::isTtype( type );
400 }
401
402 Expression * ResolveCopyCtors::makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg ) {
403 assert( var );
404 // arrays are not copy constructed, so this should always be an ExprStmt
405 ImplicitCtorDtorStmt * stmt = genCtorDtor( fname, var, cpArg );
406 ExprStmt * exprStmt = safe_dynamic_cast< ExprStmt * >( stmt->get_callStmt() );
407 Expression * untyped = exprStmt->get_expr();
408
409 // resolve copy constructor
410 // should only be one alternative for copy ctor and dtor expressions, since all arguments are fixed
411 // (VariableExpr and already resolved expression)
412 CP_CTOR_PRINT( std::cerr << "ResolvingCtorDtor " << untyped << std::endl; )
413 Expression * resolved = ResolvExpr::findVoidExpression( untyped, *this );
414 assert( resolved );
415 if ( resolved->get_env() ) {
416 // Extract useful information and discard new environments. Keeping them causes problems in PolyMutator passes.
417 env->add( *resolved->get_env() );
418 delete resolved->get_env();
419 resolved->set_env( nullptr );
420 } // if
421
422 delete stmt;
423 return resolved;
424 }
425
426 void ResolveCopyCtors::copyConstructArg( Expression *& arg, ImplicitCopyCtorExpr * impCpCtorExpr ) {
427 static UniqueName tempNamer("_tmp_cp");
428 assert( env );
429 CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *env << std::endl; )
430 assert( arg->has_result() );
431 Type * result = arg->get_result();
432 if ( skipCopyConstruct( result ) ) return; // skip certain non-copyable types
433
434 // type may involve type variables, so apply type substitution to get temporary variable's actual type
435 result = result->clone();
436 env->apply( result );
437 ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), Type::StorageClasses(), LinkageSpec::C, 0, result, 0 );
438 tmp->get_type()->set_const( false );
439
440 // create and resolve copy constructor
441 CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; )
442 Expression * cpCtor = makeCtorDtor( "?{}", tmp, arg );
443
444 if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( cpCtor ) ) {
445 // if the chosen constructor is intrinsic, the copy is unnecessary, so
446 // don't create the temporary and don't call the copy constructor
447 VariableExpr * function = dynamic_cast< VariableExpr * >( appExpr->get_function() );
448 assert( function );
449 if ( function->get_var()->get_linkage() == LinkageSpec::Intrinsic ) return;
450 }
451
452 // replace argument to function call with temporary
453 arg = new CommaExpr( cpCtor, new VariableExpr( tmp ) );
454 impCpCtorExpr->get_tempDecls().push_back( tmp );
455 impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", tmp ) );
456 }
457
458 void ResolveCopyCtors::destructRet( ObjectDecl * ret, ImplicitCopyCtorExpr * impCpCtorExpr ) {
459 impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
460 }
461
462 void ResolveCopyCtors::visit( ImplicitCopyCtorExpr *impCpCtorExpr ) {
463 CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; )
464 Parent::visit( impCpCtorExpr );
465 env = envMap.at(impCpCtorExpr);
466 assert( env );
467
468 ApplicationExpr * appExpr = impCpCtorExpr->get_callExpr();
469
470 // take each argument and attempt to copy construct it.
471 for ( Expression * & arg : appExpr->get_args() ) {
472 copyConstructArg( arg, impCpCtorExpr );
473 } // for
474
475 // each return value from the call needs to be connected with an ObjectDecl at the call site, which is
476 // initialized with the return value and is destructed later
477 // xxx - handle named return values?
478 Type * result = appExpr->get_result();
479 if ( ! result->isVoid() ) {
480 static UniqueName retNamer("_tmp_cp_ret");
481 result = result->clone();
482 env->apply( result );
483 ObjectDecl * ret = new ObjectDecl( retNamer.newName(), Type::StorageClasses(), LinkageSpec::C, 0, result, 0 );
484 ret->get_type()->set_const( false );
485 impCpCtorExpr->get_returnDecls().push_back( ret );
486 CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; )
487 if ( ! result->get_lvalue() ) {
488 // destructing lvalue returns is bad because it can cause multiple destructor calls to the same object - the returned object is not a temporary
489 destructRet( ret, impCpCtorExpr );
490 }
491 } // for
492 CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; )
493 }
494
495 void ResolveCopyCtors::visit( StmtExpr * stmtExpr ) {
496 Parent::visit( stmtExpr );
497 env = envMap.at(stmtExpr);
498 assert( stmtExpr->get_result() );
499 Type * result = stmtExpr->get_result();
500 if ( ! result->isVoid() ) {
501 static UniqueName retNamer("_tmp_stmtexpr_ret");
502
503 // create variable that will hold the result of the stmt expr
504 result = result->clone();
505 env->apply( result );
506 ObjectDecl * ret = new ObjectDecl( retNamer.newName(), Type::StorageClasses(), LinkageSpec::C, 0, result, 0 );
507 ret->get_type()->set_const( false );
508 stmtExpr->get_returnDecls().push_front( ret );
509
510 // must have a non-empty body, otherwise it wouldn't have a result
511 CompoundStmt * body = stmtExpr->get_statements();
512 assert( ! body->get_kids().empty() );
513 // must be an ExprStmt, otherwise it wouldn't have a result
514 ExprStmt * last = safe_dynamic_cast< ExprStmt * >( body->get_kids().back() );
515 last->set_expr( makeCtorDtor( "?{}", ret, last->get_expr() ) );
516
517 stmtExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
518 } // if
519
520 }
521
522 void ResolveCopyCtors::visit( UniqueExpr * unqExpr ) {
523 static std::unordered_set< int > vars;
524 unqCount[ unqExpr->get_id() ]++; // count the number of unique expressions for each ID
525 if ( vars.count( unqExpr->get_id() ) ) {
526 // xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated
527 return;
528 }
529
530 Parent::visit( unqExpr );
531 // it should never be necessary to wrap a void-returning expression in a UniqueExpr - if this assumption changes, this needs to be rethought
532 assert( unqExpr->get_result() );
533 if ( ImplicitCopyCtorExpr * impCpCtorExpr = dynamic_cast<ImplicitCopyCtorExpr*>( unqExpr->get_expr() ) ) {
534 // note the variable used as the result from the call
535 assert( impCpCtorExpr->get_result() && impCpCtorExpr->get_returnDecls().size() == 1 );
536 unqExpr->set_var( new VariableExpr( impCpCtorExpr->get_returnDecls().front() ) );
537 } else {
538 // expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression
539 unqExpr->set_object( new ObjectDecl( toString("_unq", unqExpr->get_id()), Type::StorageClasses(), LinkageSpec::C, nullptr, unqExpr->get_result()->clone(), nullptr ) );
540 unqExpr->set_var( new VariableExpr( unqExpr->get_object() ) );
541 }
542 vars.insert( unqExpr->get_id() );
543 }
544
545 Expression * FixCopyCtors::mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) {
546 CP_CTOR_PRINT( std::cerr << "FixCopyCtors: " << impCpCtorExpr << std::endl; )
547
548 impCpCtorExpr = safe_dynamic_cast< ImplicitCopyCtorExpr * >( Parent::mutate( impCpCtorExpr ) );
549 std::list< ObjectDecl * > & tempDecls = impCpCtorExpr->get_tempDecls();
550 std::list< ObjectDecl * > & returnDecls = impCpCtorExpr->get_returnDecls();
551 std::list< Expression * > & dtors = impCpCtorExpr->get_dtors();
552
553 // add all temporary declarations and their constructors
554 for ( ObjectDecl * obj : tempDecls ) {
555 stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
556 } // for
557 for ( ObjectDecl * obj : returnDecls ) {
558 stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
559 } // for
560
561 // add destructors after current statement
562 for ( Expression * dtor : dtors ) {
563 stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
564 } // for
565
566 // xxx - update to work with multiple return values
567 ObjectDecl * returnDecl = returnDecls.empty() ? NULL : returnDecls.front();
568 Expression * callExpr = impCpCtorExpr->get_callExpr();
569
570 CP_CTOR_PRINT( std::cerr << "Coming out the back..." << impCpCtorExpr << std::endl; )
571
572 // detach fields from wrapper node so that it can be deleted without deleting too much
573 dtors.clear();
574 tempDecls.clear();
575 returnDecls.clear();
576 impCpCtorExpr->set_callExpr( NULL );
577 impCpCtorExpr->set_env( NULL );
578 delete impCpCtorExpr;
579
580 if ( returnDecl ) {
581 UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
582 assign->get_args().push_back( new VariableExpr( returnDecl ) );
583 assign->get_args().push_back( callExpr );
584 // know the result type of the assignment is the type of the LHS (minus the pointer), so
585 // add that onto the assignment expression so that later steps have the necessary information
586 assign->set_result( returnDecl->get_type()->clone() );
587
588 Expression * retExpr = new CommaExpr( assign, new VariableExpr( returnDecl ) );
589 if ( callExpr->get_result()->get_lvalue() ) {
590 // lvalue returning functions are funny. Lvalue.cc inserts a *? in front of any lvalue returning
591 // non-intrinsic function. Add an AddressExpr to the call to negate the derefence and change the
592 // type of the return temporary from T to T* to properly capture the return value. Then dereference
593 // the result of the comma expression, since the lvalue returning call was originally wrapped with
594 // an AddressExpr. Effectively, this turns
595 // lvalue T f();
596 // &*f();
597 // into
598 // T * f();
599 // T * tmp_cp_retN;
600 // &*(tmp_cp_retN = &*f(), tmp_cp_retN); // the first * and second & are generated here
601 // which work out in terms of types, but is pretty messy. It would be nice to find a better way.
602 assign->get_args().back() = new AddressExpr( assign->get_args().back() );
603
604 returnDecl->set_type( new PointerType( Type::Qualifiers(), returnDecl->get_type() ) );
605 retExpr->set_result( new PointerType( Type::Qualifiers(), retExpr->get_result() ) );
606 retExpr = UntypedExpr::createDeref( retExpr );
607 } // if
608 // move env from callExpr to retExpr
609 retExpr->set_env( callExpr->get_env() );
610 callExpr->set_env( nullptr );
611 return retExpr;
612 } else {
613 return callExpr;
614 } // if
615 }
616
617 Expression * FixCopyCtors::mutate( StmtExpr * stmtExpr ) {
618 // function call temporaries should be placed at statement-level, rather than nested inside of a new statement expression,
619 // since temporaries can be shared across sub-expressions, e.g.
620 // [A, A] f();
621 // g([A] x, [A] y);
622 // f(g());
623 // f is executed once, so the return temporary is shared across the tuple constructors for x and y.
624 std::list< Statement * > & stmts = stmtExpr->get_statements()->get_kids();
625 for ( Statement *& stmt : stmts ) {
626 stmt = stmt->acceptMutator( *this );
627 } // for
628 // stmtExpr = safe_dynamic_cast< StmtExpr * >( Parent::mutate( stmtExpr ) );
629 assert( stmtExpr->get_result() );
630 Type * result = stmtExpr->get_result();
631 if ( ! result->isVoid() ) {
632 for ( ObjectDecl * obj : stmtExpr->get_returnDecls() ) {
633 stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
634 } // for
635 // add destructors after current statement
636 for ( Expression * dtor : stmtExpr->get_dtors() ) {
637 stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
638 } // for
639 // must have a non-empty body, otherwise it wouldn't have a result
640 CompoundStmt * body = stmtExpr->get_statements();
641 assert( ! body->get_kids().empty() );
642 assert( ! stmtExpr->get_returnDecls().empty() );
643 body->get_kids().push_back( new ExprStmt( noLabels, new VariableExpr( stmtExpr->get_returnDecls().front() ) ) );
644 stmtExpr->get_returnDecls().clear();
645 stmtExpr->get_dtors().clear();
646 }
647 assert( stmtExpr->get_returnDecls().empty() );
648 assert( stmtExpr->get_dtors().empty() );
649 return stmtExpr;
650 }
651
652 Expression * FixCopyCtors::mutate( UniqueExpr * unqExpr ) {
653 unqCount[ unqExpr->get_id() ]--;
654 static std::unordered_map< int, std::list< Statement * > > dtors;
655 static std::unordered_map< int, UniqueExpr * > unqMap;
656 static std::unordered_set< int > addDeref;
657 // has to be done to clean up ImplicitCopyCtorExpr nodes, even when this node was skipped in previous passes
658 if ( unqMap.count( unqExpr->get_id() ) ) {
659 // take data from other UniqueExpr to ensure consistency
660 delete unqExpr->get_expr();
661 unqExpr->set_expr( unqMap[unqExpr->get_id()]->get_expr()->clone() );
662 delete unqExpr->get_result();
663 unqExpr->set_result( maybeClone( unqExpr->get_expr()->get_result() ) );
664 if ( unqCount[ unqExpr->get_id() ] == 0 ) { // insert destructor after the last use of the unique expression
665 stmtsToAddAfter.splice( stmtsToAddAfter.end(), dtors[ unqExpr->get_id() ] );
666 }
667 if ( addDeref.count( unqExpr->get_id() ) ) {
668 // other UniqueExpr was dereferenced because it was an lvalue return, so this one should be too
669 return UntypedExpr::createDeref( unqExpr );
670 }
671 return unqExpr;
672 }
673 FixCopyCtors fixer( unqCount );
674 unqExpr->set_expr( unqExpr->get_expr()->acceptMutator( fixer ) ); // stmtexprs contained should not be separately fixed, so this must occur after the lookup
675 stmtsToAdd.splice( stmtsToAdd.end(), fixer.stmtsToAdd );
676 unqMap[unqExpr->get_id()] = unqExpr;
677 if ( unqCount[ unqExpr->get_id() ] == 0 ) { // insert destructor after the last use of the unique expression
678 stmtsToAddAfter.splice( stmtsToAddAfter.end(), dtors[ unqExpr->get_id() ] );
679 } else { // remember dtors for last instance of unique expr
680 dtors[ unqExpr->get_id() ] = fixer.stmtsToAddAfter;
681 }
682 if ( UntypedExpr * deref = dynamic_cast< UntypedExpr * >( unqExpr->get_expr() ) ) {
683 // unique expression is now a dereference, because the inner expression is an lvalue returning function call.
684 // Normalize the expression by dereferencing the unique expression, rather than the inner expression
685 // (i.e. move the dereference out a level)
686 assert( getFunctionName( deref ) == "*?" );
687 unqExpr->set_expr( getCallArg( deref, 0 ) );
688 getCallArg( deref, 0 ) = unqExpr;
689 addDeref.insert( unqExpr->get_id() );
690 return deref;
691 }
692 return unqExpr;
693 }
694
695 DeclarationWithType *FixInit::postmutate( ObjectDecl *objDecl ) {
696 // since this removes the init field from objDecl, it must occur after children are mutated (i.e. postmutate)
697 if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
698 // a decision should have been made by the resolver, so ctor and init are not both non-NULL
699 assert( ! ctorInit->get_ctor() || ! ctorInit->get_init() );
700 if ( Statement * ctor = ctorInit->get_ctor() ) {
701 if ( objDecl->get_storageClasses().is_static ) {
702 // originally wanted to take advantage of gcc nested functions, but
703 // we get memory errors with this approach. To remedy this, the static
704 // variable is hoisted when the destructor needs to be called.
705 //
706 // generate:
707 // static T __objName_static_varN;
708 // void __objName_dtor_atexitN() {
709 // __dtor__...;
710 // }
711 // int f(...) {
712 // ...
713 // static bool __objName_uninitialized = true;
714 // if (__objName_uninitialized) {
715 // __ctor(__objName);
716 // __objName_uninitialized = false;
717 // atexit(__objName_dtor_atexitN);
718 // }
719 // ...
720 // }
721
722 static UniqueName dtorCallerNamer( "_dtor_atexit" );
723
724 // static bool __objName_uninitialized = true
725 BasicType * boolType = new BasicType( Type::Qualifiers(), BasicType::Bool );
726 SingleInit * boolInitExpr = new SingleInit( new ConstantExpr( Constant::from_int( 1 ) ), noDesignators );
727 ObjectDecl * isUninitializedVar = new ObjectDecl( objDecl->get_mangleName() + "_uninitialized", Type::StorageClasses( Type::Static ), LinkageSpec::Cforall, 0, boolType, boolInitExpr );
728 isUninitializedVar->fixUniqueId();
729
730 // __objName_uninitialized = false;
731 UntypedExpr * setTrue = new UntypedExpr( new NameExpr( "?=?" ) );
732 setTrue->get_args().push_back( new VariableExpr( isUninitializedVar ) );
733 setTrue->get_args().push_back( new ConstantExpr( Constant::from_int( 0 ) ) );
734
735 // generate body of if
736 CompoundStmt * initStmts = new CompoundStmt( noLabels );
737 std::list< Statement * > & body = initStmts->get_kids();
738 body.push_back( ctor );
739 body.push_back( new ExprStmt( noLabels, setTrue ) );
740
741 // put it all together
742 IfStmt * ifStmt = new IfStmt( noLabels, new VariableExpr( isUninitializedVar ), initStmts, 0 );
743 stmtsToAddAfter.push_back( new DeclStmt( noLabels, isUninitializedVar ) );
744 stmtsToAddAfter.push_back( ifStmt );
745
746 Statement * dtor = ctorInit->get_dtor();
747 objDecl->set_init( NULL );
748 ctorInit->set_ctor( NULL );
749 ctorInit->set_dtor( nullptr );
750 if ( dtor ) {
751 // if the object has a non-trivial destructor, have to
752 // hoist it and the object into the global space and
753 // call the destructor function with atexit.
754
755 Statement * dtorStmt = dtor->clone();
756
757 // void __objName_dtor_atexitN(...) {...}
758 FunctionDecl * dtorCaller = new FunctionDecl( objDecl->get_mangleName() + dtorCallerNamer.newName(), Type::StorageClasses( Type::Static ), LinkageSpec::C, new FunctionType( Type::Qualifiers(), false ), new CompoundStmt( noLabels ) );
759 dtorCaller->fixUniqueId();
760 dtorCaller->get_statements()->push_back( dtorStmt );
761
762 // atexit(dtor_atexit);
763 UntypedExpr * callAtexit = new UntypedExpr( new NameExpr( "atexit" ) );
764 callAtexit->get_args().push_back( new VariableExpr( dtorCaller ) );
765
766 body.push_back( new ExprStmt( noLabels, callAtexit ) );
767
768 // hoist variable and dtor caller decls to list of decls that will be added into global scope
769 staticDtorDecls.push_back( objDecl );
770 staticDtorDecls.push_back( dtorCaller );
771
772 // need to rename object uniquely since it now appears
773 // at global scope and there could be multiple function-scoped
774 // static variables with the same name in different functions.
775 // Note: it isn't sufficient to modify only the mangleName, because
776 // then subsequent Indexer passes can choke on seeing the object's name
777 // if another object has the same name and type. An unfortunate side-effect
778 // of renaming the object is that subsequent NameExprs may fail to resolve,
779 // but there shouldn't be any remaining past this point.
780 static UniqueName staticNamer( "_static_var" );
781 objDecl->set_name( objDecl->get_name() + staticNamer.newName() );
782 objDecl->set_mangleName( SymTab::Mangler::mangle( objDecl ) );
783
784 // xxx - temporary hack: need to return a declaration, but want to hoist the current object out of this scope
785 // create a new object which is never used
786 static UniqueName dummyNamer( "_dummy" );
787 ObjectDecl * dummy = new ObjectDecl( dummyNamer.newName(), Type::StorageClasses( Type::Static ), LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), 0, std::list< Attribute * >{ new Attribute("unused") } );
788 delete ctorInit;
789 return dummy;
790 }
791 } else {
792 ImplicitCtorDtorStmt * implicit = safe_dynamic_cast< ImplicitCtorDtorStmt * > ( ctor );
793 ExprStmt * ctorStmt = dynamic_cast< ExprStmt * >( implicit->get_callStmt() );
794 ApplicationExpr * ctorCall = nullptr;
795 if ( ctorStmt && (ctorCall = isIntrinsicCallExpr( ctorStmt->get_expr() )) && ctorCall->get_args().size() == 2 ) {
796 // clean up intrinsic copy constructor calls by making them into SingleInits
797 objDecl->set_init( new SingleInit( ctorCall->get_args().back() ) );
798 ctorCall->get_args().pop_back();
799 } else {
800 stmtsToAddAfter.push_back( ctor );
801 objDecl->set_init( NULL );
802 ctorInit->set_ctor( NULL );
803 }
804 } // if
805 } else if ( Initializer * init = ctorInit->get_init() ) {
806 objDecl->set_init( init );
807 ctorInit->set_init( NULL );
808 } else {
809 // no constructor and no initializer, which is okay
810 objDecl->set_init( NULL );
811 } // if
812 delete ctorInit;
813 } // if
814 return objDecl;
815 }
816
817 void ObjDeclCollector::visit( CompoundStmt * compoundStmt ) {
818 std::set< ObjectDecl * > prevVars = curVars;
819 Parent::visit( compoundStmt );
820 curVars = prevVars;
821 }
822
823 void ObjDeclCollector::visit( DeclStmt * stmt ) {
824 // keep track of all variables currently in scope
825 if ( ObjectDecl * objDecl = dynamic_cast< ObjectDecl * > ( stmt->get_decl() ) ) {
826 curVars.insert( objDecl );
827 } // if
828 Parent::visit( stmt );
829 }
830
831 void LabelFinder::handleStmt( Statement * stmt ) {
832 // for each label, remember the variables in scope at that label.
833 for ( Label l : stmt->get_labels() ) {
834 vars[l] = curVars;
835 } // for
836 }
837
838 template<typename Iterator, typename OutputIterator>
839 void insertDtors( Iterator begin, Iterator end, OutputIterator out ) {
840 for ( Iterator it = begin ; it != end ; ++it ) {
841 // extract destructor statement from the object decl and insert it into the output. Note that this is
842 // only called on lists of non-static objects with implicit non-intrinsic dtors, so if the user manually
843 // calls an intrinsic dtor then the call must (and will) still be generated since the argument may
844 // contain side effects.
845 ObjectDecl * objDecl = *it;
846 ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() );
847 assert( ctorInit && ctorInit->get_dtor() );
848 *out++ = ctorInit->get_dtor()->clone();
849 } // for
850 }
851
852 void InsertDtors::visit( ObjectDecl * objDecl ) {
853 // remember non-static destructed objects so that their destructors can be inserted later
854 if ( ! objDecl->get_storageClasses().is_static ) {
855 if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
856 // a decision should have been made by the resolver, so ctor and init are not both non-NULL
857 assert( ! ctorInit->get_ctor() || ! ctorInit->get_init() );
858 Statement * dtor = ctorInit->get_dtor();
859 if ( dtor && ! isIntrinsicSingleArgCallStmt( dtor ) ) {
860 // don't need to call intrinsic dtor, because it does nothing, but
861 // non-intrinsic dtors must be called
862 reverseDeclOrder.front().push_front( objDecl );
863 } // if
864 } // if
865 } // if
866 Parent::visit( objDecl );
867 }
868
869 template< typename Visitor >
870 void handleFuncDecl( FunctionDecl * funcDecl, Visitor & visitor ) {
871 maybeAccept( funcDecl->get_functionType(), visitor );
872 maybeAccept( funcDecl->get_statements(), visitor );
873 }
874
875 void InsertDtors::visit( FunctionDecl * funcDecl ) {
876 // each function needs to have its own set of labels
877 ValueGuard< LabelFinder::LabelMap > oldLabels( labelVars );
878 labelVars.clear();
879 handleFuncDecl( funcDecl, finder );
880
881 // all labels for this function have been collected, insert destructors as appropriate.
882 // can't be Parent::mutate, because ObjDeclCollector bottoms out on FunctionDecl
883 handleFuncDecl( funcDecl, *this );
884 }
885
886 void InsertDtors::visit( CompoundStmt * compoundStmt ) {
887 // visit statements - this will also populate reverseDeclOrder list. don't want to dump all destructors
888 // when block is left, just the destructors associated with variables defined in this block, so push a new
889 // list to the top of the stack so that we can differentiate scopes
890 reverseDeclOrder.push_front( OrderedDecls() );
891 Parent::visit( compoundStmt );
892
893 // add destructors for the current scope that we're exiting, unless the last statement is a return, which
894 // causes unreachable code warnings
895 std::list< Statement * > & statements = compoundStmt->get_kids();
896 if ( ! statements.empty() && ! dynamic_cast< ReturnStmt * >( statements.back() ) ) {
897 insertDtors( reverseDeclOrder.front().begin(), reverseDeclOrder.front().end(), back_inserter( statements ) );
898 }
899 reverseDeclOrder.pop_front();
900 }
901
902 void InsertDtors::visit( __attribute((unused)) ReturnStmt * returnStmt ) {
903 // return exits all scopes, so dump destructors for all scopes
904 for ( OrderedDecls & od : reverseDeclOrder ) {
905 insertDtors( od.begin(), od.end(), back_inserter( stmtsToAdd ) );
906 } // for
907 }
908
909 // Handle break/continue/goto in the same manner as C++. Basic idea: any objects that are in scope at the
910 // BranchStmt but not at the labelled (target) statement must be destructed. If there are any objects in scope
911 // at the target location but not at the BranchStmt then those objects would be uninitialized so notify the user
912 // of the error. See C++ Reference 6.6 Jump Statements for details.
913 void InsertDtors::handleGoto( BranchStmt * stmt ) {
914 assert( stmt->get_target() != "" && "BranchStmt missing a label" );
915 // S_L = lvars = set of objects in scope at label definition
916 // S_G = curVars = set of objects in scope at goto statement
917 ObjectSet & lvars = labelVars[ stmt->get_target() ];
918
919 DTOR_PRINT(
920 std::cerr << "at goto label: " << stmt->get_target().get_name() << std::endl;
921 std::cerr << "S_G = " << printSet( curVars ) << std::endl;
922 std::cerr << "S_L = " << printSet( lvars ) << std::endl;
923 )
924
925 ObjectSet diff;
926 // S_L-S_G results in set of objects whose construction is skipped - it's an error if this set is non-empty
927 std::set_difference( lvars.begin(), lvars.end(), curVars.begin(), curVars.end(), std::inserter( diff, diff.begin() ) );
928 DTOR_PRINT(
929 std::cerr << "S_L-S_G = " << printSet( diff ) << std::endl;
930 )
931 if ( ! diff.empty() ) {
932 throw SemanticError( std::string("jump to label '") + stmt->get_target().get_name() + "' crosses initialization of " + (*diff.begin())->get_name() + " ", stmt );
933 } // if
934 // S_G-S_L results in set of objects that must be destructed
935 diff.clear();
936 std::set_difference( curVars.begin(), curVars.end(), lvars.begin(), lvars.end(), std::inserter( diff, diff.end() ) );
937 DTOR_PRINT(
938 std::cerr << "S_G-S_L = " << printSet( diff ) << std::endl;
939 )
940 if ( ! diff.empty() ) {
941 // go through decl ordered list of objectdecl. for each element that occurs in diff, output destructor
942 OrderedDecls ordered;
943 for ( OrderedDecls & rdo : reverseDeclOrder ) {
944 // add elements from reverseDeclOrder into ordered if they occur in diff - it is key that this happens in reverse declaration order.
945 copy_if( rdo.begin(), rdo.end(), back_inserter( ordered ), [&]( ObjectDecl * objDecl ) { return diff.count( objDecl ); } );
946 } // for
947 insertDtors( ordered.begin(), ordered.end(), back_inserter( stmtsToAdd ) );
948 } // if
949 }
950
951 void InsertDtors::visit( BranchStmt * stmt ) {
952 switch( stmt->get_type() ) {
953 case BranchStmt::Continue:
954 case BranchStmt::Break:
955 // could optimize the break/continue case, because the S_L-S_G check is unnecessary (this set should
956 // always be empty), but it serves as a small sanity check.
957 case BranchStmt::Goto:
958 handleGoto( stmt );
959 break;
960 default:
961 assert( false );
962 } // switch
963 }
964
965 bool checkWarnings( FunctionDecl * funcDecl ) {
966 // only check for warnings if the current function is a user-defined
967 // constructor or destructor
968 if ( ! funcDecl ) return false;
969 if ( ! funcDecl->get_statements() ) return false;
970 return isCtorDtor( funcDecl->get_name() ) && ! LinkageSpec::isOverridable( funcDecl->get_linkage() );
971 }
972
973 void GenStructMemberCalls::visit( FunctionDecl * funcDecl ) {
974 ValueGuard< FunctionDecl * > oldFunction( funcDecl );
975 ValueGuard< std::set< DeclarationWithType * > > oldUnhandled( unhandled );
976 ValueGuard< std::map< DeclarationWithType *, CodeLocation > > oldUsedUninit( usedUninit );
977 ValueGuard< ObjectDecl * > oldThisParam( thisParam );
978 ValueGuard< bool > oldIsCtor( isCtor );
979 ValueGuard< StructDecl * > oldStructDecl( structDecl );
980 errors = SemanticError(); // clear previous errors
981
982 // need to start with fresh sets
983 unhandled.clear();
984 usedUninit.clear();
985
986 function = funcDecl;
987 isCtor = isConstructor( function->get_name() );
988 if ( checkWarnings( function ) ) {
989 FunctionType * type = function->get_functionType();
990 assert( ! type->get_parameters().empty() );
991 thisParam = safe_dynamic_cast< ObjectDecl * >( type->get_parameters().front() );
992 PointerType * ptrType = safe_dynamic_cast< PointerType * > ( thisParam->get_type() );
993 StructInstType * structType = dynamic_cast< StructInstType * >( ptrType->get_base() );
994 if ( structType ) {
995 structDecl = structType->get_baseStruct();
996 for ( Declaration * member : structDecl->get_members() ) {
997 if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) {
998 // record all of the struct type's members that need to be constructed or
999 // destructed by the end of the function
1000 unhandled.insert( field );
1001 }
1002 }
1003 }
1004 }
1005 Parent::visit( function );
1006
1007 // remove the unhandled objects from usedUninit, because a call is inserted
1008 // to handle them - only objects that are later constructed are used uninitialized.
1009 std::map< DeclarationWithType *, CodeLocation > diff;
1010 // need the comparator since usedUninit and unhandled have different types
1011 struct comp_t {
1012 typedef decltype(usedUninit)::value_type usedUninit_t;
1013 typedef decltype(unhandled)::value_type unhandled_t;
1014 bool operator()(usedUninit_t x, unhandled_t y) { return x.first < y; }
1015 bool operator()(unhandled_t x, usedUninit_t y) { return x < y.first; }
1016 } comp;
1017 std::set_difference( usedUninit.begin(), usedUninit.end(), unhandled.begin(), unhandled.end(), std::inserter( diff, diff.begin() ), comp );
1018 for ( auto p : diff ) {
1019 DeclarationWithType * member = p.first;
1020 CodeLocation loc = p.second;
1021 // xxx - make error message better by also tracking the location that the object is constructed at?
1022 emit( loc, "in ", CodeGen::genPrettyType( function->get_functionType(), function->get_name() ), ", field ", member->get_name(), " used before being constructed" );
1023 }
1024
1025 if ( ! unhandled.empty() ) {
1026 // need to explicitly re-add function parameters in order to resolve copy constructors
1027 enterScope();
1028 maybeAccept( function->get_functionType(), *this );
1029
1030 // need to iterate through members in reverse in order for
1031 // ctor/dtor statements to come out in the right order
1032 for ( Declaration * member : reverseIterate( structDecl->get_members() ) ) {
1033 DeclarationWithType * field = dynamic_cast< DeclarationWithType * >( member );
1034 // skip non-DWT members
1035 if ( ! field ) continue;
1036 // skip handled members
1037 if ( ! unhandled.count( field ) ) continue;
1038
1039 // insert and resolve default/copy constructor call for each field that's unhandled
1040 std::list< Statement * > stmt;
1041 UntypedExpr * deref = UntypedExpr::createDeref( new VariableExpr( thisParam ) );
1042
1043 Expression * arg2 = 0;
1044 if ( isCopyConstructor( function ) ) {
1045 // if copy ctor, need to pass second-param-of-this-function.field
1046 std::list< DeclarationWithType * > & params = function->get_functionType()->get_parameters();
1047 assert( params.size() == 2 );
1048 arg2 = new MemberExpr( field, new VariableExpr( params.back() ) );
1049 }
1050 InitExpander srcParam( arg2 );
1051 SymTab::genImplicitCall( srcParam, new MemberExpr( field, deref ), function->get_name(), back_inserter( stmt ), field, isCtor );
1052
1053 assert( stmt.size() <= 1 );
1054 if ( stmt.size() == 1 ) {
1055 Statement * callStmt = stmt.front();
1056
1057 MutatingResolver resolver( *this );
1058 try {
1059 callStmt->acceptMutator( resolver );
1060 if ( isCtor ) {
1061 function->get_statements()->push_front( callStmt );
1062 } else {
1063 // destructor statements should be added at the end
1064 function->get_statements()->push_back( callStmt );
1065 }
1066 } catch ( SemanticError & error ) {
1067 emit( funcDecl->location, "in ", CodeGen::genPrettyType( function->get_functionType(), function->get_name() ), ", field ", field->get_name(), " not explicitly ", isCtor ? "constructed" : "destructed", " and no ", isCtor ? "default constructor" : "destructor", " found" );
1068 }
1069 }
1070 }
1071 leaveScope();
1072 }
1073 if (! errors.isEmpty()) {
1074 throw errors;
1075 }
1076 }
1077
1078 void GenStructMemberCalls::visit( ApplicationExpr * appExpr ) {
1079 if ( ! checkWarnings( function ) ) return;
1080
1081 std::string fname = getFunctionName( appExpr );
1082 if ( fname == function->get_name() ) {
1083 // call to same kind of function
1084 Expression * firstParam = appExpr->get_args().front();
1085
1086 if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( firstParam ) ) {
1087 // if calling another constructor on thisParam, assume that function handles
1088 // all members - if it doesn't a warning will appear in that function.
1089 if ( varExpr->get_var() == thisParam ) {
1090 unhandled.clear();
1091 }
1092 } else {
1093 // if first parameter is a member expression then
1094 // remove the member from unhandled set.
1095 handleFirstParam( firstParam );
1096 }
1097 }
1098
1099 Parent::visit( appExpr );
1100 }
1101
1102 void GenStructMemberCalls::handleFirstParam( Expression * firstParam ) {
1103 using namespace std;
1104 if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( firstParam ) ) {
1105 if ( MemberExpr * memberExpr = dynamic_cast< MemberExpr * >( addrExpr->get_arg() ) ) {
1106 if ( ApplicationExpr * deref = dynamic_cast< ApplicationExpr * >( memberExpr->get_aggregate() ) ) {
1107 if ( getFunctionName( deref ) == "*?" && deref->get_args().size() == 1 ) {
1108 if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( deref->get_args().front() ) ) {
1109 if ( varExpr->get_var() == thisParam ) {
1110 unhandled.erase( memberExpr->get_member() );
1111 }
1112 }
1113 }
1114 }
1115 }
1116 }
1117 }
1118
1119 void GenStructMemberCalls::visit( MemberExpr * memberExpr ) {
1120 if ( ! checkWarnings( function ) ) return;
1121 if ( ! isCtor ) return;
1122
1123 if ( ApplicationExpr * deref = dynamic_cast< ApplicationExpr * >( memberExpr->get_aggregate() ) ) {
1124 if ( getFunctionName( deref ) == "*?" && deref->get_args().size() == 1 ) {
1125 if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( deref->get_args().front() ) ) {
1126 if ( varExpr->get_var() == thisParam ) {
1127 if ( unhandled.count( memberExpr->get_member() ) ) {
1128 // emit a warning because a member was used before it was constructed
1129 usedUninit.insert( { memberExpr->get_member(), memberExpr->location } );
1130 }
1131 }
1132 }
1133 }
1134 }
1135 Parent::visit( memberExpr );
1136 }
1137
1138 template< typename Visitor, typename... Params >
1139 void error( Visitor & v, CodeLocation loc, const Params &... params ) {
1140 SemanticError err( toString( params... ) );
1141 err.set_location( loc );
1142 v.errors.append( err );
1143 }
1144
1145 template< typename... Params >
1146 void GenStructMemberCalls::emit( CodeLocation loc, const Params &... params ) {
1147 // toggle warnings vs. errors here.
1148 // warn( params... );
1149 error( *this, loc, params... );
1150 }
1151
1152 DeclarationWithType * MutatingResolver::mutate( ObjectDecl *objectDecl ) {
1153 // add object to the indexer assumes that there will be no name collisions
1154 // in generated code. If this changes, add mutate methods for entities with
1155 // scope and call {enter,leave}Scope explicitly.
1156 objectDecl->accept( indexer );
1157 return objectDecl;
1158 }
1159
1160 Expression* MutatingResolver::mutate( UntypedExpr *untypedExpr ) {
1161 return safe_dynamic_cast< ApplicationExpr * >( ResolvExpr::findVoidExpression( untypedExpr, indexer ) );
1162 }
1163
1164 Expression * FixCtorExprs::mutate( ConstructorExpr * ctorExpr ) {
1165 static UniqueName tempNamer( "_tmp_ctor_expr" );
1166 // xxx - is the size check necessary?
1167 assert( ctorExpr->has_result() && ctorExpr->get_result()->size() == 1 );
1168
1169 // xxx - ideally we would reuse the temporary generated from the copy constructor passes from within firstArg if it exists and not generate a temporary if it's unnecessary.
1170 ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), Type::StorageClasses(), LinkageSpec::C, nullptr, ctorExpr->get_result()->clone(), nullptr );
1171 addDeclaration( tmp );
1172
1173 // xxx - this can be TupleAssignExpr now. Need to properly handle this case.
1174 ApplicationExpr * callExpr = safe_dynamic_cast< ApplicationExpr * > ( ctorExpr->get_callExpr() );
1175 TypeSubstitution * env = ctorExpr->get_env();
1176 ctorExpr->set_callExpr( nullptr );
1177 ctorExpr->set_env( nullptr );
1178
1179 Expression *& firstArg = callExpr->get_args().front();
1180 UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
1181 assign->get_args().push_back( new VariableExpr( tmp ) );
1182 assign->get_args().push_back( firstArg );
1183 assign->set_result( ctorExpr->get_result()->clone() );
1184 firstArg = assign;
1185
1186 CommaExpr * commaExpr = new CommaExpr( callExpr, new VariableExpr( tmp ) );
1187 commaExpr->set_env( env );
1188 delete ctorExpr;
1189 return commaExpr;
1190 }
1191 } // namespace
1192} // namespace InitTweak
1193
1194// Local Variables: //
1195// tab-width: 4 //
1196// mode: c++ //
1197// compile-command: "make install" //
1198// End: //
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