source: src/InitTweak/InitTweak.cc@ 1ed958c3

new-env with_gc
Last change on this file since 1ed958c3 was 1cdfa82, checked in by Aaron Moss <a3moss@…>, 7 years ago

Merge remote-tracking branch 'origin/master' into with_gc
  • Property mode set to 100644
File size: 24.4 KB
Line 
1#include <algorithm> // for find, all_of
2#include <cassert> // for assertf, assert, strict_dynamic_cast
3#include <iostream> // for ostream, cerr, endl
4#include <iterator> // for back_insert_iterator, back_inserter
5#include <memory> // for __shared_ptr
6
7#include "Common/GC.h" // for new_static_root
8#include "Common/PassVisitor.h"
9#include "Common/SemanticError.h" // for SemanticError
10#include "Common/UniqueName.h" // for UniqueName
11#include "Common/utility.h" // for toString, deleteAll, maybeClone
12#include "GenPoly/GenPoly.h" // for getFunctionType
13#include "InitTweak.h"
14#include "Parser/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic
15#include "ResolvExpr/typeops.h" // for typesCompatibleIgnoreQualifiers
16#include "SymTab/Autogen.h"
17#include "SymTab/Indexer.h" // for Indexer
18#include "SynTree/Attribute.h" // for Attribute
19#include "SynTree/Constant.h" // for Constant
20#include "SynTree/Declaration.h" // for ObjectDecl, DeclarationWithType
21#include "SynTree/Expression.h" // for Expression, UntypedExpr, Applicati...
22#include "SynTree/Initializer.h" // for Initializer, ListInit, Designation
23#include "SynTree/Label.h" // for Label
24#include "SynTree/Statement.h" // for CompoundStmt, ExprStmt, BranchStmt
25#include "SynTree/Type.h" // for FunctionType, ArrayType, PointerType
26#include "SynTree/Visitor.h" // for Visitor, maybeAccept
27#include "Tuples/Tuples.h" // for Tuples::isTtype
28
29class UntypedValofExpr;
30
31namespace InitTweak {
32 namespace {
33 struct HasDesignations : public WithShortCircuiting {
34 bool hasDesignations = false;
35
36 void previsit( BaseSyntaxNode * ) {
37 // short circuit if we already know there are designations
38 if ( hasDesignations ) visit_children = false;
39 }
40
41 void previsit( Designation * des ) {
42 // short circuit if we already know there are designations
43 if ( hasDesignations ) visit_children = false;
44 else if ( ! des->get_designators().empty() ) {
45 hasDesignations = true;
46 visit_children = false;
47 }
48 }
49 };
50
51 struct InitDepthChecker : public WithGuards {
52 bool depthOkay = true;
53 Type * type;
54 int curDepth = 0, maxDepth = 0;
55 InitDepthChecker( Type * type ) : type( type ) {
56 Type * t = type;
57 while ( ArrayType * at = dynamic_cast< ArrayType * >( t ) ) {
58 maxDepth++;
59 t = at->get_base();
60 }
61 maxDepth++;
62 }
63 void previsit( ListInit * ) {
64 curDepth++;
65 GuardAction( [this]() { curDepth--; } );
66 if ( curDepth > maxDepth ) depthOkay = false;
67 }
68 };
69
70 struct InitFlattener : public WithShortCircuiting {
71 void previsit( SingleInit * singleInit ) {
72 visit_children = false;
73 argList.push_back( singleInit->value->clone() );
74 }
75 std::list< Expression * > argList;
76 };
77
78 }
79
80 std::list< Expression * > makeInitList( Initializer * init ) {
81 PassVisitor<InitFlattener> flattener;
82 maybeAccept( init, flattener );
83 return flattener.pass.argList;
84 }
85
86 bool isDesignated( Initializer * init ) {
87 PassVisitor<HasDesignations> finder;
88 maybeAccept( init, finder );
89 return finder.pass.hasDesignations;
90 }
91
92 bool checkInitDepth( ObjectDecl * objDecl ) {
93 PassVisitor<InitDepthChecker> checker( objDecl->type );
94 maybeAccept( objDecl->init, checker );
95 return checker.pass.depthOkay;
96 }
97
98 class InitExpander::ExpanderImpl {
99 public:
100 virtual ~ExpanderImpl() = default;
101 virtual std::list< Expression * > next( std::list< Expression * > & indices ) = 0;
102 virtual Statement * buildListInit( UntypedExpr * callExpr, std::list< Expression * > & indices ) = 0;
103 };
104
105 class InitImpl : public InitExpander::ExpanderImpl {
106 public:
107 InitImpl( Initializer * init ) : init( init ) {}
108 virtual ~InitImpl() = default;
109
110 virtual std::list< Expression * > next( __attribute((unused)) std::list< Expression * > & indices ) {
111 // this is wrong, but just a placeholder for now
112 // if ( ! flattened ) flatten( indices );
113 // return ! inits.empty() ? makeInitList( inits.front() ) : std::list< Expression * >();
114 return makeInitList( init );
115 }
116
117 virtual Statement * buildListInit( UntypedExpr * callExpr, std::list< Expression * > & indices );
118 private:
119 Initializer * init;
120 };
121
122 class ExprImpl : public InitExpander::ExpanderImpl {
123 public:
124 ExprImpl( Expression * expr ) : arg( expr ) {}
125 virtual ~ExprImpl() = default;
126
127 virtual std::list< Expression * > next( std::list< Expression * > & indices ) {
128 std::list< Expression * > ret;
129 Expression * expr = maybeClone( arg );
130 if ( expr ) {
131 for ( std::list< Expression * >::reverse_iterator it = indices.rbegin(); it != indices.rend(); ++it ) {
132 // go through indices and layer on subscript exprs ?[?]
133 ++it;
134 UntypedExpr * subscriptExpr = new UntypedExpr( new NameExpr( "?[?]") );
135 subscriptExpr->get_args().push_back( expr );
136 subscriptExpr->get_args().push_back( (*it)->clone() );
137 expr = subscriptExpr;
138 }
139 ret.push_back( expr );
140 }
141 return ret;
142 }
143
144 virtual Statement * buildListInit( UntypedExpr * callExpr, std::list< Expression * > & indices );
145 private:
146 Expression * arg;
147 };
148
149 InitExpander::InitExpander( Initializer * init ) : expander( new InitImpl( init ) ) {}
150
151 InitExpander::InitExpander( Expression * expr ) : expander( new ExprImpl( expr ) ) {}
152
153 std::list< Expression * > InitExpander::operator*() {
154 return cur;
155 }
156
157 InitExpander & InitExpander::operator++() {
158 cur = expander->next( indices );
159 return *this;
160 }
161
162 // use array indices list to build switch statement
163 void InitExpander::addArrayIndex( Expression * index, Expression * dimension ) {
164 indices.push_back( index );
165 indices.push_back( dimension );
166 }
167
168 void InitExpander::clearArrayIndices() {
169 indices.clear();
170 }
171
172 bool InitExpander::addReference() {
173 bool added = false;
174 for ( Expression *& expr : cur ) {
175 expr = new AddressExpr( expr );
176 added = true;
177 }
178 return added;
179 }
180
181 namespace {
182 /// given index i, dimension d, initializer init, and callExpr f, generates
183 /// if (i < d) f(..., init)
184 /// ++i;
185 /// so that only elements within the range of the array are constructed
186 template< typename OutIterator >
187 void buildCallExpr( UntypedExpr * callExpr, Expression * index, Expression * dimension, Initializer * init, OutIterator out ) {
188 UntypedExpr * cond = new UntypedExpr( new NameExpr( "?<?") );
189 cond->get_args().push_back( index->clone() );
190 cond->get_args().push_back( dimension->clone() );
191
192 std::list< Expression * > args = makeInitList( init );
193 callExpr->get_args().splice( callExpr->get_args().end(), args );
194
195 *out++ = new IfStmt( cond, new ExprStmt( callExpr ), nullptr );
196
197 UntypedExpr * increment = new UntypedExpr( new NameExpr( "++?" ) );
198 increment->get_args().push_back( index->clone() );
199 *out++ = new ExprStmt( increment );
200 }
201
202 template< typename OutIterator >
203 void build( UntypedExpr * callExpr, InitExpander::IndexList::iterator idx, InitExpander::IndexList::iterator idxEnd, Initializer * init, OutIterator out ) {
204 if ( idx == idxEnd ) return;
205 Expression * index = *idx++;
206 assert( idx != idxEnd );
207 Expression * dimension = *idx++;
208
209 // xxx - may want to eventually issue a warning here if we can detect
210 // that the number of elements exceeds to dimension of the array
211 if ( idx == idxEnd ) {
212 if ( ListInit * listInit = dynamic_cast< ListInit * >( init ) ) {
213 for ( Initializer * init : *listInit ) {
214 buildCallExpr( callExpr->clone(), index, dimension, init, out );
215 }
216 } else {
217 buildCallExpr( callExpr->clone(), index, dimension, init, out );
218 }
219 } else {
220 std::list< Statement * > branches;
221
222 unsigned long cond = 0;
223 ListInit * listInit = dynamic_cast< ListInit * >( init );
224 if ( ! listInit ) {
225 // xxx - this shouldn't be an error, but need a way to
226 // terminate without creating output, so should catch this error
227 SemanticError( init->location, "unbalanced list initializers" );
228 }
229
230 static UniqueName targetLabel( "L__autogen__" );
231 Label switchLabel( targetLabel.newName(), 0, std::list< Attribute * >{ new Attribute("unused") } );
232 for ( Initializer * init : *listInit ) {
233 Expression * condition;
234 // check for designations
235 // if ( init-> ) {
236 condition = new ConstantExpr( Constant::from_ulong( cond ) );
237 ++cond;
238 // } else {
239 // condition = // ... take designation
240 // cond = // ... take designation+1
241 // }
242 std::list< Statement * > stmts;
243 build( callExpr, idx, idxEnd, init, back_inserter( stmts ) );
244 stmts.push_back( new BranchStmt( switchLabel, BranchStmt::Break ) );
245 CaseStmt * caseStmt = new CaseStmt( condition, stmts );
246 branches.push_back( caseStmt );
247 }
248 *out++ = new SwitchStmt( index->clone(), branches );
249 *out++ = new NullStmt( { switchLabel } );
250 }
251 }
252 }
253
254 // if array came with an initializer list: initialize each element
255 // may have more initializers than elements in the array - need to check at each index that
256 // we haven't exceeded size.
257 // may have fewer initializers than elements in the array - need to default construct
258 // remaining elements.
259 // To accomplish this, generate switch statement, consuming all of expander's elements
260 Statement * InitImpl::buildListInit( UntypedExpr * dst, std::list< Expression * > & indices ) {
261 if ( ! init ) return nullptr;
262 CompoundStmt * block = new CompoundStmt();
263 build( dst, indices.begin(), indices.end(), init, back_inserter( block->get_kids() ) );
264 if ( block->get_kids().empty() ) {
265 return nullptr;
266 } else {
267 init = nullptr; // init was consumed in creating the list init
268 return block;
269 }
270 }
271
272 Statement * ExprImpl::buildListInit( UntypedExpr *, std::list< Expression * > & ) {
273 return nullptr;
274 }
275
276 Statement * InitExpander::buildListInit( UntypedExpr * dst ) {
277 return expander->buildListInit( dst, indices );
278 }
279
280 Type * getTypeofThis( FunctionType * ftype ) {
281 assertf( ftype, "getTypeofThis: nullptr ftype" );
282 ObjectDecl * thisParam = getParamThis( ftype );
283 ReferenceType * refType = strict_dynamic_cast< ReferenceType * >( thisParam->type );
284 return refType->base;
285 }
286
287 ObjectDecl * getParamThis( FunctionType * ftype ) {
288 assertf( ftype, "getParamThis: nullptr ftype" );
289 auto & params = ftype->parameters;
290 assertf( ! params.empty(), "getParamThis: ftype with 0 parameters: %s", toString( ftype ).c_str() );
291 return strict_dynamic_cast< ObjectDecl * >( params.front() );
292 }
293
294 bool tryConstruct( DeclarationWithType * dwt ) {
295 ObjectDecl * objDecl = dynamic_cast< ObjectDecl * >( dwt );
296 if ( ! objDecl ) return false;
297 return (objDecl->get_init() == nullptr ||
298 ( objDecl->get_init() != nullptr && objDecl->get_init()->get_maybeConstructed() ))
299 && ! objDecl->get_storageClasses().is_extern
300 && isConstructable( objDecl->type );
301 }
302
303 bool isConstructable( Type * type ) {
304 return ! dynamic_cast< VarArgsType * >( type ) && ! dynamic_cast< ReferenceType * >( type ) && ! dynamic_cast< FunctionType * >( type ) && ! Tuples::isTtype( type );
305 }
306
307 struct CallFinder {
308 CallFinder( const std::list< std::string > & names ) : names( names ) {}
309
310 void postvisit( ApplicationExpr * appExpr ) {
311 handleCallExpr( appExpr );
312 }
313
314 void postvisit( UntypedExpr * untypedExpr ) {
315 handleCallExpr( untypedExpr );
316 }
317
318 std::list< Expression * > * matches;
319 private:
320 const std::list< std::string > names;
321
322 template< typename CallExpr >
323 void handleCallExpr( CallExpr * expr ) {
324 std::string fname = getFunctionName( expr );
325 if ( std::find( names.begin(), names.end(), fname ) != names.end() ) {
326 matches->push_back( expr );
327 }
328 }
329 };
330
331 void collectCtorDtorCalls( Statement * stmt, std::list< Expression * > & matches ) {
332 static PassVisitor<CallFinder> finder( std::list< std::string >{ "?{}", "^?{}" } );
333 finder.pass.matches = &matches;
334 maybeAccept( stmt, finder );
335 }
336
337 Expression * getCtorDtorCall( Statement * stmt ) {
338 std::list< Expression * > matches;
339 collectCtorDtorCalls( stmt, matches );
340 assert( matches.size() <= 1 );
341 return matches.size() == 1 ? matches.front() : nullptr;
342 }
343
344 namespace {
345 DeclarationWithType * getCalledFunction( Expression * expr );
346
347 template<typename CallExpr>
348 DeclarationWithType * handleDerefCalledFunction( CallExpr * expr ) {
349 // (*f)(x) => should get "f"
350 std::string name = getFunctionName( expr );
351 assertf( name == "*?", "Unexpected untyped expression: %s", name.c_str() );
352 assertf( ! expr->get_args().empty(), "Cannot get called function from dereference with no arguments" );
353 return getCalledFunction( expr->get_args().front() );
354 }
355
356 DeclarationWithType * getCalledFunction( Expression * expr ) {
357 assert( expr );
358 if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( expr ) ) {
359 return varExpr->var;
360 } else if ( MemberExpr * memberExpr = dynamic_cast< MemberExpr * >( expr ) ) {
361 return memberExpr->member;
362 } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
363 return getCalledFunction( castExpr->arg );
364 } else if ( UntypedExpr * untypedExpr = dynamic_cast< UntypedExpr * >( expr ) ) {
365 return handleDerefCalledFunction( untypedExpr );
366 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
367 return handleDerefCalledFunction( appExpr );
368 } else if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( expr ) ) {
369 return getCalledFunction( addrExpr->arg );
370 } else if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( expr ) ) {
371 return getCalledFunction( commaExpr->arg2 );
372 }
373 return nullptr;
374 }
375 }
376
377 DeclarationWithType * getFunction( Expression * expr ) {
378 if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( expr ) ) {
379 return getCalledFunction( appExpr->get_function() );
380 } else if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * > ( expr ) ) {
381 return getCalledFunction( untyped->get_function() );
382 }
383 assertf( false, "getFunction received unknown expression: %s", toString( expr ).c_str() );
384 }
385
386 ApplicationExpr * isIntrinsicCallExpr( Expression * expr ) {
387 ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( expr );
388 if ( ! appExpr ) return nullptr;
389 DeclarationWithType * function = getCalledFunction( appExpr->get_function() );
390 assertf( function, "getCalledFunction returned nullptr: %s", toString( appExpr->get_function() ).c_str() );
391 // check for Intrinsic only - don't want to remove all overridable ctor/dtors because autogenerated ctor/dtor
392 // will call all member dtors, and some members may have a user defined dtor.
393 return function->get_linkage() == LinkageSpec::Intrinsic ? appExpr : nullptr;
394 }
395
396 namespace {
397 template <typename Predicate>
398 bool allofCtorDtor( Statement * stmt, const Predicate & pred ) {
399 std::list< Expression * > callExprs;
400 collectCtorDtorCalls( stmt, callExprs );
401 // if ( callExprs.empty() ) return false; // xxx - do I still need this check?
402 return std::all_of( callExprs.begin(), callExprs.end(), pred);
403 }
404 }
405
406 bool isIntrinsicSingleArgCallStmt( Statement * stmt ) {
407 return allofCtorDtor( stmt, []( Expression * callExpr ){
408 if ( ApplicationExpr * appExpr = isIntrinsicCallExpr( callExpr ) ) {
409 FunctionType *funcType = GenPoly::getFunctionType( appExpr->get_function()->get_result() );
410 assert( funcType );
411 return funcType->get_parameters().size() == 1;
412 }
413 return false;
414 });
415 }
416
417 bool isIntrinsicCallStmt( Statement * stmt ) {
418 return allofCtorDtor( stmt, []( Expression * callExpr ) {
419 return isIntrinsicCallExpr( callExpr );
420 });
421 }
422
423 namespace {
424 template<typename CallExpr>
425 Expression *& callArg( CallExpr * callExpr, unsigned int pos ) {
426 if ( pos >= callExpr->get_args().size() ) assertf( false, "getCallArg for argument that doesn't exist: (%u); %s.", pos, toString( callExpr ).c_str() );
427 for ( Expression *& arg : callExpr->get_args() ) {
428 if ( pos == 0 ) return arg;
429 pos--;
430 }
431 assert( false );
432 }
433 }
434
435 Expression *& getCallArg( Expression * callExpr, unsigned int pos ) {
436 if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( callExpr ) ) {
437 return callArg( appExpr, pos );
438 } else if ( UntypedExpr * untypedExpr = dynamic_cast< UntypedExpr * >( callExpr ) ) {
439 return callArg( untypedExpr, pos );
440 } else if ( TupleAssignExpr * tupleExpr = dynamic_cast< TupleAssignExpr * > ( callExpr ) ) {
441 std::list< Statement * > & stmts = tupleExpr->get_stmtExpr()->get_statements()->get_kids();
442 assertf( ! stmts.empty(), "TupleAssignExpr somehow has no statements." );
443 ExprStmt * stmt = strict_dynamic_cast< ExprStmt * >( stmts.back() );
444 TupleExpr * tuple = strict_dynamic_cast< TupleExpr * >( stmt->get_expr() );
445 assertf( ! tuple->get_exprs().empty(), "TupleAssignExpr somehow has empty tuple expr." );
446 return getCallArg( tuple->get_exprs().front(), pos );
447 } else if ( ImplicitCopyCtorExpr * copyCtor = dynamic_cast< ImplicitCopyCtorExpr * >( callExpr ) ) {
448 return getCallArg( copyCtor->callExpr, pos );
449 } else {
450 assertf( false, "Unexpected expression type passed to getCallArg: %s", toString( callExpr ).c_str() );
451 }
452 }
453
454 namespace {
455 std::string funcName( Expression * func );
456
457 template<typename CallExpr>
458 std::string handleDerefName( CallExpr * expr ) {
459 // (*f)(x) => should get name "f"
460 std::string name = getFunctionName( expr );
461 assertf( name == "*?", "Unexpected untyped expression: %s", name.c_str() );
462 assertf( ! expr->get_args().empty(), "Cannot get function name from dereference with no arguments" );
463 return funcName( expr->get_args().front() );
464 }
465
466 std::string funcName( Expression * func ) {
467 if ( NameExpr * nameExpr = dynamic_cast< NameExpr * >( func ) ) {
468 return nameExpr->get_name();
469 } else if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( func ) ) {
470 return varExpr->get_var()->get_name();
471 } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( func ) ) {
472 return funcName( castExpr->get_arg() );
473 } else if ( MemberExpr * memberExpr = dynamic_cast< MemberExpr * >( func ) ) {
474 return memberExpr->get_member()->get_name();
475 } else if ( UntypedMemberExpr * memberExpr = dynamic_cast< UntypedMemberExpr * > ( func ) ) {
476 return funcName( memberExpr->get_member() );
477 } else if ( UntypedExpr * untypedExpr = dynamic_cast< UntypedExpr * >( func ) ) {
478 return handleDerefName( untypedExpr );
479 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( func ) ) {
480 return handleDerefName( appExpr );
481 } else if ( ConstructorExpr * ctorExpr = dynamic_cast< ConstructorExpr * >( func ) ) {
482 return funcName( getCallArg( ctorExpr->get_callExpr(), 0 ) );
483 } else {
484 assertf( false, "Unexpected expression type being called as a function in call expression: %s", toString( func ).c_str() );
485 }
486 }
487 }
488
489 std::string getFunctionName( Expression * expr ) {
490 // there's some unforunate overlap here with getCalledFunction. Ideally this would be able to use getCalledFunction and
491 // return the name of the DeclarationWithType, but this needs to work for NameExpr and UntypedMemberExpr, where getCalledFunction
492 // can't possibly do anything reasonable.
493 if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( expr ) ) {
494 return funcName( appExpr->get_function() );
495 } else if ( UntypedExpr * untypedExpr = dynamic_cast< UntypedExpr * > ( expr ) ) {
496 return funcName( untypedExpr->get_function() );
497 } else {
498 std::cerr << expr << std::endl;
499 assertf( false, "Unexpected expression type passed to getFunctionName" );
500 }
501 }
502
503 Type * getPointerBase( Type * type ) {
504 if ( PointerType * ptrType = dynamic_cast< PointerType * >( type ) ) {
505 return ptrType->get_base();
506 } else if ( ArrayType * arrayType = dynamic_cast< ArrayType * >( type ) ) {
507 return arrayType->get_base();
508 } else if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( type ) ) {
509 return refType->get_base();
510 } else {
511 return nullptr;
512 }
513 }
514
515 Type * isPointerType( Type * type ) {
516 if ( getPointerBase( type ) ) return type;
517 else return nullptr;
518 }
519
520 ApplicationExpr * createBitwiseAssignment( Expression * dst, Expression * src ) {
521 static FunctionDecl * assign = nullptr;
522 if ( ! assign ) {
523 // temporary? Generate a fake assignment operator to represent bitwise assignments.
524 // This operator could easily exist as a real function, but it's tricky because nothing should resolve to this function.
525 TypeDecl * td = new TypeDecl( "T", noStorageClasses, nullptr, TypeDecl::Dtype, true );
526 assign = new_static_root<FunctionDecl>(
527 "?=?", noStorageClasses, LinkageSpec::Intrinsic,
528 SymTab::genAssignType( new TypeInstType( noQualifiers, td->name, td ) ), nullptr );
529 }
530 if ( dynamic_cast< ReferenceType * >( dst->result ) ) {
531 for (int depth = dst->result->referenceDepth(); depth > 0; depth--) {
532 dst = new AddressExpr( dst );
533 }
534 } else {
535 dst = new CastExpr( dst, new ReferenceType( noQualifiers, dst->result->clone() ) );
536 }
537 if ( dynamic_cast< ReferenceType * >( src->result ) ) {
538 for (int depth = src->result->referenceDepth(); depth > 0; depth--) {
539 src = new AddressExpr( src );
540 }
541 // src = new CastExpr( src, new ReferenceType( noQualifiers, src->result->stripReferences()->clone() ) );
542 }
543 return new ApplicationExpr( VariableExpr::functionPointer( assign ), { dst, src } );
544 }
545
546 struct ConstExprChecker : public WithShortCircuiting {
547 // most expressions are not const expr
548 void previsit( Expression * ) { isConstExpr = false; visit_children = false; }
549
550 void previsit( AddressExpr *addressExpr ) {
551 visit_children = false;
552
553 // address of a variable or member expression is constexpr
554 Expression * arg = addressExpr->get_arg();
555 if ( ! dynamic_cast< NameExpr * >( arg) && ! dynamic_cast< VariableExpr * >( arg ) && ! dynamic_cast< MemberExpr * >( arg ) && ! dynamic_cast< UntypedMemberExpr * >( arg ) ) isConstExpr = false;
556 }
557
558 // these expressions may be const expr, depending on their children
559 void previsit( SizeofExpr * ) {}
560 void previsit( AlignofExpr * ) {}
561 void previsit( UntypedOffsetofExpr * ) {}
562 void previsit( OffsetofExpr * ) {}
563 void previsit( OffsetPackExpr * ) {}
564 void previsit( AttrExpr * ) {}
565 void previsit( CommaExpr * ) {}
566 void previsit( LogicalExpr * ) {}
567 void previsit( ConditionalExpr * ) {}
568 void previsit( CastExpr * ) {}
569 void previsit( ConstantExpr * ) {}
570
571 void previsit( VariableExpr * varExpr ) {
572 visit_children = false;
573
574 if ( EnumInstType * inst = dynamic_cast< EnumInstType * >( varExpr->result ) ) {
575 long long int value;
576 if ( inst->baseEnum->valueOf( varExpr->var, value ) ) {
577 // enumerators are const expr
578 return;
579 }
580 }
581 isConstExpr = false;
582 }
583
584 bool isConstExpr = true;
585 };
586
587 bool isConstExpr( Expression * expr ) {
588 if ( expr ) {
589 PassVisitor<ConstExprChecker> checker;
590 expr->accept( checker );
591 return checker.pass.isConstExpr;
592 }
593 return true;
594 }
595
596 bool isConstExpr( Initializer * init ) {
597 if ( init ) {
598 PassVisitor<ConstExprChecker> checker;
599 init->accept( checker );
600 return checker.pass.isConstExpr;
601 } // if
602 // for all intents and purposes, no initializer means const expr
603 return true;
604 }
605
606 bool isConstructor( const std::string & str ) { return str == "?{}"; }
607 bool isDestructor( const std::string & str ) { return str == "^?{}"; }
608 bool isAssignment( const std::string & str ) { return str == "?=?"; }
609 bool isCtorDtor( const std::string & str ) { return isConstructor( str ) || isDestructor( str ); }
610 bool isCtorDtorAssign( const std::string & str ) { return isCtorDtor( str ) || isAssignment( str ); }
611
612 FunctionDecl * isCopyFunction( Declaration * decl, const std::string & fname ) {
613 FunctionDecl * function = dynamic_cast< FunctionDecl * >( decl );
614 if ( ! function ) return nullptr;
615 if ( function->name != fname ) return nullptr;
616 FunctionType * ftype = function->type;
617 if ( ftype->parameters.size() != 2 ) return nullptr;
618
619 Type * t1 = getPointerBase( ftype->get_parameters().front()->get_type() );
620 Type * t2 = ftype->parameters.back()->get_type();
621 assert( t1 );
622
623 if ( ResolvExpr::typesCompatibleIgnoreQualifiers( t1, t2, SymTab::Indexer() ) ) {
624 return function;
625 } else {
626 return nullptr;
627 }
628 }
629
630 FunctionDecl * isAssignment( Declaration * decl ) {
631 return isCopyFunction( decl, "?=?" );
632 }
633 FunctionDecl * isDestructor( Declaration * decl ) {
634 if ( isDestructor( decl->get_name() ) ) {
635 return dynamic_cast< FunctionDecl * >( decl );
636 }
637 return nullptr;
638 }
639 FunctionDecl * isDefaultConstructor( Declaration * decl ) {
640 if ( isConstructor( decl->name ) ) {
641 if ( FunctionDecl * func = dynamic_cast< FunctionDecl * >( decl ) ) {
642 if ( func->type->parameters.size() == 1 ) {
643 return func;
644 }
645 }
646 }
647 return nullptr;
648 }
649 FunctionDecl * isCopyConstructor( Declaration * decl ) {
650 return isCopyFunction( decl, "?{}" );
651 }
652}
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