source: src/InitTweak/InitTweak.cc@ 41fcd94

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 41fcd94 was caab997, checked in by Rob Schluntz <rschlunt@…>, 8 years ago

Recognize enumerators as constexpr
  • Property mode set to 100644
File size: 24.2 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/PassVisitor.h"
8#include "Common/SemanticError.h" // for SemanticError
9#include "Common/UniqueName.h" // for UniqueName
10#include "Common/utility.h" // for toString, deleteAll, maybeClone
11#include "GenPoly/GenPoly.h" // for getFunctionType
12#include "InitTweak.h"
13#include "Parser/LinkageSpec.h" // for Spec, isBuiltin, Intrinsic
14#include "ResolvExpr/typeops.h" // for typesCompatibleIgnoreQualifiers
15#include "SymTab/Autogen.h"
16#include "SymTab/Indexer.h" // for Indexer
17#include "SynTree/Attribute.h" // for Attribute
18#include "SynTree/Constant.h" // for Constant
19#include "SynTree/Declaration.h" // for ObjectDecl, DeclarationWithType
20#include "SynTree/Expression.h" // for Expression, UntypedExpr, Applicati...
21#include "SynTree/Initializer.h" // for Initializer, ListInit, Designation
22#include "SynTree/Label.h" // for Label
23#include "SynTree/Statement.h" // for CompoundStmt, ExprStmt, BranchStmt
24#include "SynTree/Type.h" // for FunctionType, ArrayType, PointerType
25#include "SynTree/Visitor.h" // for Visitor, maybeAccept
26#include "Tuples/Tuples.h" // for Tuples::isTtype
27
28class UntypedValofExpr;
29
30namespace InitTweak {
31 namespace {
32 struct HasDesignations : public WithShortCircuiting {
33 bool hasDesignations = false;
34
35 void previsit( BaseSyntaxNode * ) {
36 // short circuit if we already know there are designations
37 if ( hasDesignations ) visit_children = false;
38 }
39
40 void previsit( Designation * des ) {
41 // short circuit if we already know there are designations
42 if ( hasDesignations ) visit_children = false;
43 else if ( ! des->get_designators().empty() ) {
44 hasDesignations = true;
45 visit_children = false;
46 }
47 }
48 };
49
50 struct InitDepthChecker : public WithGuards {
51 bool depthOkay = true;
52 Type * type;
53 int curDepth = 0, maxDepth = 0;
54 InitDepthChecker( Type * type ) : type( type ) {
55 Type * t = type;
56 while ( ArrayType * at = dynamic_cast< ArrayType * >( t ) ) {
57 maxDepth++;
58 t = at->get_base();
59 }
60 maxDepth++;
61 }
62 void previsit( ListInit * ) {
63 curDepth++;
64 GuardAction( [this]() { curDepth--; } );
65 if ( curDepth > maxDepth ) depthOkay = false;
66 }
67 };
68
69 struct InitFlattener : public WithShortCircuiting {
70 void previsit( SingleInit * singleInit ) {
71 visit_children = false;
72 argList.push_back( singleInit->value->clone() );
73 }
74 std::list< Expression * > argList;
75 };
76
77 }
78
79 std::list< Expression * > makeInitList( Initializer * init ) {
80 PassVisitor<InitFlattener> flattener;
81 maybeAccept( init, flattener );
82 return flattener.pass.argList;
83 }
84
85 bool isDesignated( Initializer * init ) {
86 PassVisitor<HasDesignations> finder;
87 maybeAccept( init, finder );
88 return finder.pass.hasDesignations;
89 }
90
91 bool checkInitDepth( ObjectDecl * objDecl ) {
92 PassVisitor<InitDepthChecker> checker( objDecl->type );
93 maybeAccept( objDecl->init, checker );
94 return checker.pass.depthOkay;
95 }
96
97 class InitExpander::ExpanderImpl {
98 public:
99 virtual ~ExpanderImpl() = default;
100 virtual std::list< Expression * > next( std::list< Expression * > & indices ) = 0;
101 virtual Statement * buildListInit( UntypedExpr * callExpr, std::list< Expression * > & indices ) = 0;
102 };
103
104 class InitImpl : public InitExpander::ExpanderImpl {
105 public:
106 InitImpl( Initializer * init ) : init( init ) {}
107 virtual ~InitImpl() = default;
108
109 virtual std::list< Expression * > next( __attribute((unused)) std::list< Expression * > & indices ) {
110 // this is wrong, but just a placeholder for now
111 // if ( ! flattened ) flatten( indices );
112 // return ! inits.empty() ? makeInitList( inits.front() ) : std::list< Expression * >();
113 return makeInitList( init );
114 }
115
116 virtual Statement * buildListInit( UntypedExpr * callExpr, std::list< Expression * > & indices );
117 private:
118 Initializer * init;
119 };
120
121 class ExprImpl : public InitExpander::ExpanderImpl {
122 public:
123 ExprImpl( Expression * expr ) : arg( expr ) {}
124 virtual ~ExprImpl() { delete arg; }
125
126 virtual std::list< Expression * > next( std::list< Expression * > & indices ) {
127 std::list< Expression * > ret;
128 Expression * expr = maybeClone( arg );
129 if ( expr ) {
130 for ( std::list< Expression * >::reverse_iterator it = indices.rbegin(); it != indices.rend(); ++it ) {
131 // go through indices and layer on subscript exprs ?[?]
132 ++it;
133 UntypedExpr * subscriptExpr = new UntypedExpr( new NameExpr( "?[?]") );
134 subscriptExpr->get_args().push_back( expr );
135 subscriptExpr->get_args().push_back( (*it)->clone() );
136 expr = subscriptExpr;
137 }
138 ret.push_back( expr );
139 }
140 return ret;
141 }
142
143 virtual Statement * buildListInit( UntypedExpr * callExpr, std::list< Expression * > & indices );
144 private:
145 Expression * arg;
146 };
147
148 InitExpander::InitExpander( Initializer * init ) : expander( new InitImpl( init ) ) {}
149
150 InitExpander::InitExpander( Expression * expr ) : expander( new ExprImpl( expr ) ) {}
151
152 std::list< Expression * > InitExpander::operator*() {
153 return cur;
154 }
155
156 InitExpander & InitExpander::operator++() {
157 cur = expander->next( indices );
158 return *this;
159 }
160
161 // use array indices list to build switch statement
162 void InitExpander::addArrayIndex( Expression * index, Expression * dimension ) {
163 indices.push_back( index );
164 indices.push_back( dimension );
165 }
166
167 void InitExpander::clearArrayIndices() {
168 deleteAll( indices );
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 throw SemanticError( "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 delete block;
266 return nullptr;
267 } else {
268 init = nullptr; // init was consumed in creating the list init
269 return block;
270 }
271 }
272
273 Statement * ExprImpl::buildListInit( UntypedExpr *, std::list< Expression * > & ) {
274 return nullptr;
275 }
276
277 Statement * InitExpander::buildListInit( UntypedExpr * dst ) {
278 return expander->buildListInit( dst, indices );
279 }
280
281 Type * getTypeofThis( FunctionType * ftype ) {
282 assertf( ftype, "getTypeofThis: nullptr ftype" );
283 ObjectDecl * thisParam = getParamThis( ftype );
284 ReferenceType * refType = strict_dynamic_cast< ReferenceType * >( thisParam->type );
285 return refType->base;
286 }
287
288 ObjectDecl * getParamThis( FunctionType * ftype ) {
289 assertf( ftype, "getParamThis: nullptr ftype" );
290 auto & params = ftype->parameters;
291 assertf( ! params.empty(), "getParamThis: ftype with 0 parameters: %s", toString( ftype ).c_str() );
292 return strict_dynamic_cast< ObjectDecl * >( params.front() );
293 }
294
295 bool tryConstruct( DeclarationWithType * dwt ) {
296 ObjectDecl * objDecl = dynamic_cast< ObjectDecl * >( dwt );
297 if ( ! objDecl ) return false;
298 return ! LinkageSpec::isBuiltin( objDecl->get_linkage() ) &&
299 (objDecl->get_init() == nullptr ||
300 ( objDecl->get_init() != nullptr && objDecl->get_init()->get_maybeConstructed() ))
301 && ! objDecl->get_storageClasses().is_extern
302 && isConstructable( objDecl->type );
303 }
304
305 bool isConstructable( Type * type ) {
306 return ! dynamic_cast< VarArgsType * >( type ) && ! dynamic_cast< ReferenceType * >( type ) && ! dynamic_cast< FunctionType * >( type ) && ! Tuples::isTtype( type );
307 }
308
309 struct CallFinder {
310 CallFinder( const std::list< std::string > & names ) : names( names ) {}
311
312 void postvisit( ApplicationExpr * appExpr ) {
313 handleCallExpr( appExpr );
314 }
315
316 void postvisit( UntypedExpr * untypedExpr ) {
317 handleCallExpr( untypedExpr );
318 }
319
320 std::list< Expression * > * matches;
321 private:
322 const std::list< std::string > names;
323
324 template< typename CallExpr >
325 void handleCallExpr( CallExpr * expr ) {
326 std::string fname = getFunctionName( expr );
327 if ( std::find( names.begin(), names.end(), fname ) != names.end() ) {
328 matches->push_back( expr );
329 }
330 }
331 };
332
333 void collectCtorDtorCalls( Statement * stmt, std::list< Expression * > & matches ) {
334 static PassVisitor<CallFinder> finder( std::list< std::string >{ "?{}", "^?{}" } );
335 finder.pass.matches = &matches;
336 maybeAccept( stmt, finder );
337 }
338
339 Expression * getCtorDtorCall( Statement * stmt ) {
340 std::list< Expression * > matches;
341 collectCtorDtorCalls( stmt, matches );
342 assert( matches.size() <= 1 );
343 return matches.size() == 1 ? matches.front() : nullptr;
344 }
345
346 namespace {
347 DeclarationWithType * getCalledFunction( Expression * expr );
348
349 template<typename CallExpr>
350 DeclarationWithType * handleDerefCalledFunction( CallExpr * expr ) {
351 // (*f)(x) => should get "f"
352 std::string name = getFunctionName( expr );
353 assertf( name == "*?", "Unexpected untyped expression: %s", name.c_str() );
354 assertf( ! expr->get_args().empty(), "Cannot get called function from dereference with no arguments" );
355 return getCalledFunction( expr->get_args().front() );
356 }
357
358 DeclarationWithType * getCalledFunction( Expression * expr ) {
359 assert( expr );
360 if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( expr ) ) {
361 return varExpr->var;
362 } else if ( MemberExpr * memberExpr = dynamic_cast< MemberExpr * >( expr ) ) {
363 return memberExpr->member;
364 } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( expr ) ) {
365 return getCalledFunction( castExpr->arg );
366 } else if ( UntypedExpr * untypedExpr = dynamic_cast< UntypedExpr * >( expr ) ) {
367 return handleDerefCalledFunction( untypedExpr );
368 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * > ( expr ) ) {
369 return handleDerefCalledFunction( appExpr );
370 } else if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( expr ) ) {
371 return getCalledFunction( addrExpr->arg );
372 } else if ( CommaExpr * commaExpr = dynamic_cast< CommaExpr * >( expr ) ) {
373 return getCalledFunction( commaExpr->arg2 );
374 }
375 return nullptr;
376 }
377 }
378
379 DeclarationWithType * getFunction( Expression * expr ) {
380 if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( expr ) ) {
381 return getCalledFunction( appExpr->get_function() );
382 } else if ( UntypedExpr * untyped = dynamic_cast< UntypedExpr * > ( expr ) ) {
383 return getCalledFunction( untyped->get_function() );
384 }
385 assertf( false, "getFunction received unknown expression: %s", toString( expr ).c_str() );
386 }
387
388 ApplicationExpr * isIntrinsicCallExpr( Expression * expr ) {
389 ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( expr );
390 if ( ! appExpr ) return nullptr;
391 DeclarationWithType * function = getCalledFunction( appExpr->get_function() );
392 assertf( function, "getCalledFunction returned nullptr: %s", toString( appExpr->get_function() ).c_str() );
393 // check for Intrinsic only - don't want to remove all overridable ctor/dtors because autogenerated ctor/dtor
394 // will call all member dtors, and some members may have a user defined dtor.
395 return function->get_linkage() == LinkageSpec::Intrinsic ? appExpr : nullptr;
396 }
397
398 namespace {
399 template <typename Predicate>
400 bool allofCtorDtor( Statement * stmt, const Predicate & pred ) {
401 std::list< Expression * > callExprs;
402 collectCtorDtorCalls( stmt, callExprs );
403 // if ( callExprs.empty() ) return false; // xxx - do I still need this check?
404 return std::all_of( callExprs.begin(), callExprs.end(), pred);
405 }
406 }
407
408 bool isIntrinsicSingleArgCallStmt( Statement * stmt ) {
409 return allofCtorDtor( stmt, []( Expression * callExpr ){
410 if ( ApplicationExpr * appExpr = isIntrinsicCallExpr( callExpr ) ) {
411 FunctionType *funcType = GenPoly::getFunctionType( appExpr->get_function()->get_result() );
412 assert( funcType );
413 return funcType->get_parameters().size() == 1;
414 }
415 return false;
416 });
417 }
418
419 bool isIntrinsicCallStmt( Statement * stmt ) {
420 return allofCtorDtor( stmt, []( Expression * callExpr ) {
421 return isIntrinsicCallExpr( callExpr );
422 });
423 }
424
425 namespace {
426 template<typename CallExpr>
427 Expression *& callArg( CallExpr * callExpr, unsigned int pos ) {
428 if ( pos >= callExpr->get_args().size() ) assertf( false, "getCallArg for argument that doesn't exist: (%u); %s.", pos, toString( callExpr ).c_str() );
429 for ( Expression *& arg : callExpr->get_args() ) {
430 if ( pos == 0 ) return arg;
431 pos--;
432 }
433 assert( false );
434 }
435 }
436
437 Expression *& getCallArg( Expression * callExpr, unsigned int pos ) {
438 if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( callExpr ) ) {
439 return callArg( appExpr, pos );
440 } else if ( UntypedExpr * untypedExpr = dynamic_cast< UntypedExpr * >( callExpr ) ) {
441 return callArg( untypedExpr, pos );
442 } else if ( TupleAssignExpr * tupleExpr = dynamic_cast< TupleAssignExpr * > ( callExpr ) ) {
443 std::list< Statement * > & stmts = tupleExpr->get_stmtExpr()->get_statements()->get_kids();
444 assertf( ! stmts.empty(), "TupleAssignExpr somehow has no statements." );
445 ExprStmt * stmt = strict_dynamic_cast< ExprStmt * >( stmts.back() );
446 TupleExpr * tuple = strict_dynamic_cast< TupleExpr * >( stmt->get_expr() );
447 assertf( ! tuple->get_exprs().empty(), "TupleAssignExpr somehow has empty tuple expr." );
448 return getCallArg( tuple->get_exprs().front(), pos );
449 } else if ( ImplicitCopyCtorExpr * copyCtor = dynamic_cast< ImplicitCopyCtorExpr * >( callExpr ) ) {
450 return getCallArg( copyCtor->callExpr, pos );
451 } else {
452 assertf( false, "Unexpected expression type passed to getCallArg: %s", toString( callExpr ).c_str() );
453 }
454 }
455
456 namespace {
457 std::string funcName( Expression * func );
458
459 template<typename CallExpr>
460 std::string handleDerefName( CallExpr * expr ) {
461 // (*f)(x) => should get name "f"
462 std::string name = getFunctionName( expr );
463 assertf( name == "*?", "Unexpected untyped expression: %s", name.c_str() );
464 assertf( ! expr->get_args().empty(), "Cannot get function name from dereference with no arguments" );
465 return funcName( expr->get_args().front() );
466 }
467
468 std::string funcName( Expression * func ) {
469 if ( NameExpr * nameExpr = dynamic_cast< NameExpr * >( func ) ) {
470 return nameExpr->get_name();
471 } else if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( func ) ) {
472 return varExpr->get_var()->get_name();
473 } else if ( CastExpr * castExpr = dynamic_cast< CastExpr * >( func ) ) {
474 return funcName( castExpr->get_arg() );
475 } else if ( MemberExpr * memberExpr = dynamic_cast< MemberExpr * >( func ) ) {
476 return memberExpr->get_member()->get_name();
477 } else if ( UntypedMemberExpr * memberExpr = dynamic_cast< UntypedMemberExpr * > ( func ) ) {
478 return funcName( memberExpr->get_member() );
479 } else if ( UntypedExpr * untypedExpr = dynamic_cast< UntypedExpr * >( func ) ) {
480 return handleDerefName( untypedExpr );
481 } else if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( func ) ) {
482 return handleDerefName( appExpr );
483 } else if ( ConstructorExpr * ctorExpr = dynamic_cast< ConstructorExpr * >( func ) ) {
484 return funcName( getCallArg( ctorExpr->get_callExpr(), 0 ) );
485 } else {
486 assertf( false, "Unexpected expression type being called as a function in call expression: %s", toString( func ).c_str() );
487 }
488 }
489 }
490
491 std::string getFunctionName( Expression * expr ) {
492 // there's some unforunate overlap here with getCalledFunction. Ideally this would be able to use getCalledFunction and
493 // return the name of the DeclarationWithType, but this needs to work for NameExpr and UntypedMemberExpr, where getCalledFunction
494 // can't possibly do anything reasonable.
495 if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( expr ) ) {
496 return funcName( appExpr->get_function() );
497 } else if ( UntypedExpr * untypedExpr = dynamic_cast< UntypedExpr * > ( expr ) ) {
498 return funcName( untypedExpr->get_function() );
499 } else {
500 std::cerr << expr << std::endl;
501 assertf( false, "Unexpected expression type passed to getFunctionName" );
502 }
503 }
504
505 Type * getPointerBase( Type * type ) {
506 if ( PointerType * ptrType = dynamic_cast< PointerType * >( type ) ) {
507 return ptrType->get_base();
508 } else if ( ArrayType * arrayType = dynamic_cast< ArrayType * >( type ) ) {
509 return arrayType->get_base();
510 } else if ( ReferenceType * refType = dynamic_cast< ReferenceType * >( type ) ) {
511 return refType->get_base();
512 } else {
513 return nullptr;
514 }
515 }
516
517 Type * isPointerType( Type * type ) {
518 if ( getPointerBase( type ) ) return type;
519 else return nullptr;
520 }
521
522 ApplicationExpr * createBitwiseAssignment( Expression * dst, Expression * src ) {
523 static FunctionDecl * assign = nullptr;
524 if ( ! assign ) {
525 // temporary? Generate a fake assignment operator to represent bitwise assignments.
526 // This operator could easily exist as a real function, but it's tricky because nothing should resolve to this function.
527 TypeDecl * td = new TypeDecl( "T", noStorageClasses, nullptr, TypeDecl::Dtype, true );
528 assign = new FunctionDecl( "?=?", noStorageClasses, LinkageSpec::Intrinsic, SymTab::genAssignType( new TypeInstType( noQualifiers, td->name, td ) ), nullptr );
529 }
530 if ( dynamic_cast< ReferenceType * >( dst->result ) ) {
531 dst = new AddressExpr( dst );
532 } else {
533 dst = new CastExpr( dst, new ReferenceType( noQualifiers, dst->result->clone() ) );
534 }
535 if ( dynamic_cast< ReferenceType * >( src->result ) ) {
536 src = new CastExpr( src, new ReferenceType( noQualifiers, src->result->stripReferences()->clone() ) );
537 }
538 return new ApplicationExpr( VariableExpr::functionPointer( assign ), { dst, src } );
539 }
540
541 struct ConstExprChecker : public WithShortCircuiting {
542 // most expressions are not const expr
543 void previsit( Expression * ) { isConstExpr = false; visit_children = false; }
544
545 void previsit( AddressExpr *addressExpr ) {
546 visit_children = false;
547
548 // address of a variable or member expression is constexpr
549 Expression * arg = addressExpr->get_arg();
550 if ( ! dynamic_cast< NameExpr * >( arg) && ! dynamic_cast< VariableExpr * >( arg ) && ! dynamic_cast< MemberExpr * >( arg ) && ! dynamic_cast< UntypedMemberExpr * >( arg ) ) isConstExpr = false;
551 }
552
553 // these expressions may be const expr, depending on their children
554 void previsit( SizeofExpr * ) {}
555 void previsit( AlignofExpr * ) {}
556 void previsit( UntypedOffsetofExpr * ) {}
557 void previsit( OffsetofExpr * ) {}
558 void previsit( OffsetPackExpr * ) {}
559 void previsit( AttrExpr * ) {}
560 void previsit( CommaExpr * ) {}
561 void previsit( LogicalExpr * ) {}
562 void previsit( ConditionalExpr * ) {}
563 void previsit( CastExpr * ) {}
564 void previsit( ConstantExpr * ) {}
565
566 void previsit( VariableExpr * varExpr ) {
567 visit_children = false;
568
569 if ( EnumInstType * inst = dynamic_cast< EnumInstType * >( varExpr->result ) ) {
570 long long int value;
571 if ( inst->baseEnum->valueOf( varExpr->var, value ) ) {
572 // enumerators are const expr
573 return;
574 }
575 }
576 isConstExpr = false;
577 }
578
579 bool isConstExpr = true;
580 };
581
582 bool isConstExpr( Expression * expr ) {
583 if ( expr ) {
584 PassVisitor<ConstExprChecker> checker;
585 expr->accept( checker );
586 return checker.pass.isConstExpr;
587 }
588 return true;
589 }
590
591 bool isConstExpr( Initializer * init ) {
592 if ( init ) {
593 PassVisitor<ConstExprChecker> checker;
594 init->accept( checker );
595 return checker.pass.isConstExpr;
596 } // if
597 // for all intents and purposes, no initializer means const expr
598 return true;
599 }
600
601 bool isConstructor( const std::string & str ) { return str == "?{}"; }
602 bool isDestructor( const std::string & str ) { return str == "^?{}"; }
603 bool isAssignment( const std::string & str ) { return str == "?=?"; }
604 bool isCtorDtor( const std::string & str ) { return isConstructor( str ) || isDestructor( str ); }
605 bool isCtorDtorAssign( const std::string & str ) { return isCtorDtor( str ) || isAssignment( str ); }
606
607 FunctionDecl * isCopyFunction( Declaration * decl, const std::string & fname ) {
608 FunctionDecl * function = dynamic_cast< FunctionDecl * >( decl );
609 if ( ! function ) return nullptr;
610 if ( function->name != fname ) return nullptr;
611 FunctionType * ftype = function->type;
612 if ( ftype->parameters.size() != 2 ) return nullptr;
613
614 Type * t1 = getPointerBase( ftype->get_parameters().front()->get_type() );
615 Type * t2 = ftype->parameters.back()->get_type();
616 assert( t1 );
617
618 if ( ResolvExpr::typesCompatibleIgnoreQualifiers( t1, t2, SymTab::Indexer() ) ) {
619 return function;
620 } else {
621 return nullptr;
622 }
623 }
624
625 FunctionDecl * isAssignment( Declaration * decl ) {
626 return isCopyFunction( decl, "?=?" );
627 }
628 FunctionDecl * isDestructor( Declaration * decl ) {
629 if ( isDestructor( decl->get_name() ) ) {
630 return dynamic_cast< FunctionDecl * >( decl );
631 }
632 return nullptr;
633 }
634 FunctionDecl * isDefaultConstructor( Declaration * decl ) {
635 if ( isConstructor( decl->name ) ) {
636 if ( FunctionDecl * func = dynamic_cast< FunctionDecl * >( decl ) ) {
637 if ( func->type->parameters.size() == 1 ) {
638 return func;
639 }
640 }
641 }
642 return nullptr;
643 }
644 FunctionDecl * isCopyConstructor( Declaration * decl ) {
645 return isCopyFunction( decl, "?{}" );
646 }
647}
Note: See TracBrowser for help on using the repository browser.