source: src/GenPoly/LvalueNew.cpp@ 9749d2fa

ADT ast-experimental
Last change on this file since 9749d2fa was 7fffb1b, checked in by Andrew Beach <ajbeach@…>, 3 years ago

Translated the convertLvalue pass. It could possibly use some additional clean-up.

  • Property mode set to 100644
File size: 22.7 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// LvalueNew.cpp -- Clean up lvalues and remove references.
8//
9// Author : Andrew Beach
10// Created On : Thu Sep 15 14:08:00 2022
11// Last Modified By : Andrew Beach
12// Last Modified On : Wed Oct 6 9:59:00 2022
13// Update Count : 0
14//
15
16#include "Lvalue.h"
17
18#include <set>
19#include <iostream>
20
21#include "AST/Copy.hpp" // for deepCopy
22#include "AST/Expr.hpp"
23#include "AST/Inspect.hpp"
24#include "AST/LinkageSpec.hpp" // for Linkage
25#include "AST/Pass.hpp"
26#include "Common/SemanticError.h" // for SemanticWarning
27#include "Common/UniqueName.h" // for UniqueName
28#include "GenPoly/GenPoly.h" // for genFunctionType
29#include "ResolvExpr/typeops.h" // for typesCompatible
30#include "ResolvExpr/Unify.h" // for unify
31
32#if 0
33#define PRINT(x) x
34#else
35#define PRINT(x)
36#endif
37
38namespace GenPoly {
39
40namespace {
41
42/// Intrinsic functions that return references now instead return lvalues.
43struct FixIntrinsicResults final : public ast::WithGuards {
44 enum {
45 NoSkip,
46 Skip,
47 SkipInProgress,
48 } skip = NoSkip;
49
50 void previsit( ast::AsmExpr const * ) {
51 GuardValue( skip ) = Skip;
52 }
53 void previsit( ast::ApplicationExpr const * ) {
54 GuardValue( skip ) = (skip == Skip) ? SkipInProgress : NoSkip;
55 }
56
57 ast::Expr const * postvisit( ast::ApplicationExpr const * expr );
58 void previsit( ast::FunctionDecl const * decl );
59 bool inIntrinsic = false;
60};
61
62/// Add de-references around address-of operations on reference types.
63struct AddressRef final :
64 public ast::WithConstTranslationUnit,
65 public ast::WithGuards,
66 public ast::WithShortCircuiting,
67 public ast::WithVisitorRef<AddressRef> {
68 void previsit( ast::AddressExpr const * expr );
69 ast::Expr const * postvisit( ast::AddressExpr const * expr );
70 void previsit( ast::Expr const * expr );
71 ast::ApplicationExpr const * previsit( ast::ApplicationExpr const * expr );
72 void previsit( ast::SingleInit const * init );
73
74 void handleNonAddr( ast::Expr const * expr );
75
76 bool first = true;
77 bool current = false;
78 bool addCast = false;
79 int refDepth = 0;
80};
81
82/// Handles casts between references and pointers,
83/// creating temporaries for the conversion.
84struct ReferenceConversions final :
85 public ast::WithConstTranslationUnit,
86 public ast::WithGuards, public ast::WithStmtsToAdd<> {
87 ast::Expr const * postvisit( ast::CastExpr const * expr );
88 ast::Expr const * postvisit( ast::AddressExpr const * expr );
89};
90
91/// Intrinsic functions that take reference parameters don't actually do.
92/// Their reference arguments must be implicity dereferenced.
93/// TODO Also appears to contain redundent code with AddressRef
94struct FixIntrinsicArgs final :
95 public ast::WithConstTranslationUnit {
96 ast::Expr const * postvisit( ast::ApplicationExpr const * expr );
97};
98
99/// Removes redundant &* / *& patterns that may be generated.
100struct CollapseAddressDeref final {
101 ast::Expr const * postvisit( ast::AddressExpr const * expr );
102 ast::Expr const * postvisit( ast::ApplicationExpr const * expr );
103};
104
105/// GCC-like Generalized Lvalues (which have since been removed from GCC).
106/// https://gcc.gnu.org/onlinedocs/gcc-3.4.6/gcc/Lvalues.html#Lvalues
107/// Replaces &(a,b) with (a, &b), &(a ? b : c) with (a ? &b : &c)
108struct GeneralizedLvalue final :
109 public ast::WithVisitorRef<GeneralizedLvalue> {
110 ast::Expr const * postvisit( ast::AddressExpr const * expr );
111 ast::Expr const * postvisit( ast::MemberExpr const * expr );
112
113 template<typename Node, typename Func>
114 ast::Expr const * applyTransformation(
115 Node const * expr, ast::ptr<ast::Expr> Node::*field, Func mkExpr );
116};
117
118/// Replace all reference types with pointer types.
119struct ReferenceTypeElimination final {
120 ast::Type const * postvisit( ast::ReferenceType const * type );
121};
122
123/// True for intrinsic function calls that return an lvalue in C.
124bool isIntrinsicReference( ast::Expr const * expr ) {
125 // The known intrinsic-reference prelude functions.
126 static std::set<std::string> const lvalueFunctions = { "*?", "?[?]" };
127 if ( auto untyped = dynamic_cast<ast::UntypedExpr const *>( expr ) ) {
128 std::string fname = ast::getFunctionName( untyped );
129 return lvalueFunctions.count( fname );
130 } else if ( auto app = dynamic_cast<ast::ApplicationExpr const *>( expr ) ) {
131 if ( auto func = ast::getFunction( app ) ) {
132 return func->linkage == ast::Linkage::Intrinsic
133 && lvalueFunctions.count( func->name );
134 }
135 }
136 return false;
137}
138
139// A maybe typed variant of the createDeref function (only UntypedExpr).
140ast::Expr * mkDeref(
141 ast::TranslationGlobal const & global, ast::Expr const * arg ) {
142 if ( global.dereference ) {
143 // Note: Reference depth can be arbitrarily deep here,
144 // so peel off the outermost pointer/reference, not just
145 // pointer because they are effecitvely equivalent in this pass
146 ast::VariableExpr * deref = new ast::VariableExpr(
147 arg->location, global.dereference );
148 deref->result = new ast::PointerType( deref->result );
149 ast::Type const * base = ast::getPointerBase( arg->result );
150 assertf( base, "expected pointer type in dereference (type was %s)", toString( arg->result ).c_str() );
151 ast::ApplicationExpr * ret =
152 new ast::ApplicationExpr( arg->location, deref, { arg } );
153 ret->result = ast::deepCopy( base );
154 return ret;
155 } else {
156 return ast::UntypedExpr::createDeref( arg->location, arg );
157 }
158}
159
160ast::Expr const * FixIntrinsicResults::postvisit(
161 ast::ApplicationExpr const * expr ) {
162 if ( skip == SkipInProgress || !isIntrinsicReference( expr ) ) {
163 return expr;
164 }
165 // Eliminate reference types from intrinsic applications
166 // now they return lvalues.
167 ast::ptr<ast::ReferenceType> result =
168 expr->result.strict_as<ast::ReferenceType>();
169 expr = ast::mutate_field( expr, &ast::ApplicationExpr::result,
170 ast::deepCopy( result->base ) );
171 if ( inIntrinsic ) {
172 return expr;
173 }
174 // When not in an intrinsic function, add a cast to don't add cast when
175 // in an intrinsic function, since they already have the cast.
176 auto * ret = new ast::CastExpr( expr->location, expr, result.get() );
177 ret->env = expr->env;
178 return ret;
179}
180
181void FixIntrinsicResults::previsit( ast::FunctionDecl const * decl ) {
182 GuardValue( inIntrinsic ) = decl->linkage == ast::Linkage::Intrinsic;
183}
184
185void AddressRef::previsit( ast::AddressExpr const * ) {
186 // Is this the first address-of in the chain?
187 GuardValue( current ) = first;
188 // Later references will not be for next address-of to be first in chain.
189 GuardValue( first ) = false;
190 // If is the outermost address-of in a chain:
191 if ( current ) {
192 // Set depth to 0 so that postvisit can
193 // find the innermost address-of easily.
194 GuardValue( refDepth ) = 0;
195 }
196}
197
198ast::Expr const * AddressRef::postvisit( ast::AddressExpr const * expr ) {
199 PRINT( std::cerr << "addr ref at " << expr << std::endl; )
200 if ( 0 == refDepth ) {
201 PRINT( std::cerr << "depth 0, get new depth..." << std::endl; )
202 // Is this the innermost address-of in a chain? record depth D.
203 if ( isIntrinsicReference( expr->arg ) ) {
204 assertf( false, "AddrRef : address-of should not have intrinsic reference argument: %s", toCString( expr->arg ) );
205 } else {
206 // try to avoid ?[?]
207 // TODO is this condition still necessary? intrinsicReferences
208 // should have a cast around them at this point, so I don't think
209 // this condition ever fires.
210 refDepth = expr->arg->result->referenceDepth();
211 PRINT( std::cerr << "arg not intrinsic reference, new depth is: " << refDepth << std::endl; )
212 }
213 }
214 if ( current ) {
215 PRINT( std::cerr << "current, depth is: " << refDepth << std::endl; )
216 ast::Expr const * ret = expr;
217 while ( refDepth ) {
218 // Add one dereference for each address-of in the chain.
219 ret = mkDeref( transUnit().global, ret );
220 --refDepth;
221 }
222
223 // if addrExpr depth is 0, then the result is a pointer because the
224 // arg was depth 1 and not lvalue. This means the dereference result
225 // is not a reference, is lvalue, and one less pointer depth than the
226 // addrExpr. Thus the cast is meaningless.
227 // TODO: One thing to double check is whether it is possible for the
228 // types to differ outside of the single pointer level (i.e. can the
229 // base type of addrExpr differ from the type of addrExpr-arg?). If
230 // so then the cast might need to be added, conditional on a more
231 // sophisticated check.
232 if ( addCast && 0 != expr->result->referenceDepth() ) {
233 PRINT( std::cerr << "adding cast to " << expr->result << std::endl; )
234 return new ast::CastExpr( expr->location,
235 ret, ast::deepCopy( expr->result ) );
236 }
237 return ret;
238 }
239 PRINT( std::cerr << "not current..." << std::endl; )
240 return expr;
241}
242
243void AddressRef::previsit( ast::Expr const * expr ) {
244 handleNonAddr( expr );
245 GuardValue( addCast ) = false;
246}
247
248// So we want to skip traversing to the head?
249ast::ApplicationExpr const * AddressRef::previsit(
250 ast::ApplicationExpr const * expr ) {
251 visit_children = false;
252 GuardValue( addCast );
253 handleNonAddr( expr );
254 auto mutExpr = ast::mutate( expr );
255 for ( ast::ptr<ast::Expr> & arg : mutExpr->args ) {
256 addCast = true;
257 arg = arg->accept( *visitor );
258 }
259 return mutExpr;
260}
261
262void AddressRef::previsit( ast::SingleInit const * ) {
263 // Each initialization context with address-of requires a cast.
264 GuardValue( addCast ) = true;
265}
266
267// idea: &&&E: get outer &, inner &
268// at inner &, record depth D of reference type of argument of &.
269// at auter &, add D derefs.
270void AddressRef::handleNonAddr( ast::Expr const * ) {
271 // non-address-of: reset status variables:
272 // * current expr is NOT the first address-of expr in an address-of chain.
273 // * next seen address-of expr IS the first in the chain.
274 GuardValue( current ) = false;
275 GuardValue( first ) = true;
276}
277
278ast::Expr const * ReferenceConversions::postvisit(
279 ast::CastExpr const * expr ) {
280 // TODO: Is it possible to convert directly between reference types with
281 // a different base. e.g.
282 // int x;
283 // (double&)x;
284 // At the moment, I (who?) am working off of the assumption that this is
285 // illegal, thus the cast becomes redundant after this pass, so trash the
286 // cast altogether. If that changes, care must be taken to insert the
287 // correct pointer casts in the right places.
288
289 // Note: reference depth difference is the determining factor in what
290 // code is run, rather than whether something is reference type or not,
291 // since conversion still needs to occur when both types are references
292 // that differ in depth.
293 ast::Type const * dstType = expr->result.get();
294 ast::Type const * srcType = expr->arg->result.get();
295 assertf( dstType, "Cast to no type in: %s", toCString( expr ) );
296 assertf( srcType, "Cast from no type in: %s", toCString( expr ) );
297 int dstDepth = dstType->referenceDepth();
298 int srcDepth = srcType->referenceDepth();
299 int diff = dstDepth - srcDepth;
300
301 if ( 0 < diff && !expr->arg->get_lvalue() ) {
302 // rvalue to reference conversion -- introduce temporary
303 // know that reference depth of cast argument is 0
304 // (int &&&)3;
305 // becomes
306 // int __ref_tmp_0 = 3;
307 // int & __ref_tmp_1 = &__ref_tmp_0;
308 // int && __ref_tmp_2 = &__ref_tmp_1;
309 // &__ref_tmp_2;
310 // The last & comes from the remaining reference conversion code.
311 SemanticWarning( expr->arg->location,
312 Warning::RvalueToReferenceConversion, toCString( expr->arg ) );
313
314 static UniqueName tmpNamer( "__ref_tmp_" );
315 ast::ObjectDecl * tmp = new ast::ObjectDecl( expr->arg->location,
316 tmpNamer.newName(),
317 ast::deepCopy( expr->arg->result ),
318 new ast::SingleInit( expr->arg->location, expr->arg ) );
319 PRINT( std::cerr << "make tmp: " << tmp << std::endl; )
320 stmtsToAddBefore.push_back( new ast::DeclStmt( tmp->location, tmp ) );
321 for ( int i = 0 ; i < dstDepth - 1 ; ++i ) {
322 ast::ObjectDecl * newTmp = new ast::ObjectDecl( tmp->location,
323 tmpNamer.newName(),
324 new ast::ReferenceType( ast::deepCopy( tmp->type ) ),
325 new ast::SingleInit( tmp->location,
326 new ast::AddressExpr( tmp->location,
327 new ast::VariableExpr( tmp->location, tmp ) ) ) );
328 PRINT( std::cerr << "make tmp: " << i << ": " << newTmp << std::endl; )
329 stmtsToAddBefore.push_back(
330 new ast::DeclStmt( newTmp->location, newTmp ) );
331 tmp = newTmp;
332 }
333 // Update diff so that remaining code works out correctly.
334 expr = ast::mutate_field( expr, &ast::CastExpr::arg,
335 new ast::VariableExpr( tmp->location, tmp ) );
336 PRINT( std::cerr << "update cast to: " << expr << std::endl; )
337 srcType = expr->arg->result;
338 srcDepth = srcType->referenceDepth();
339 diff = dstDepth - srcDepth;
340 assert( 1 == diff );
341 }
342
343 // Handle conversion between different depths.
344 PRINT(
345 if ( dstDepth || srcDepth ) {
346 std::cerr << "dstType: " << dstType << " / srcType: " << srcType << '\n';
347 std::cerr << "depth: " << dstDepth << " / " << srcDepth << std::endl;
348 }
349 )
350 // Conversion to type with more depth/more references.
351 // Add address-of for each level of difference.
352 if ( 0 < diff ) {
353 ast::Expr * ret = ast::mutate( expr->arg.get() );
354 for ( int i = 0 ; i < diff ; ++i ) {
355 ret = new ast::AddressExpr( ret->location, ret );
356 }
357 if ( expr->arg->get_lvalue() &&
358 !ResolvExpr::typesCompatible(
359 srcType,
360 strict_dynamic_cast<ast::ReferenceType const *>( dstType )->base,
361 ast::SymbolTable() ) ) {
362 // Must keep cast if cast-to type is different from the actual type.
363 return ast::mutate_field( expr, &ast::CastExpr::arg, ret );
364 }
365 ret->env = expr->env;
366 ret->result = expr->result;
367 return ret;
368 // Conversion to type with less depth/fewer references.
369 // Add dereferences for each level of difference.
370 } else if ( diff < 0 ) {
371 ast::Expr * ret = ast::mutate( expr->arg.get() );
372 for ( int i = 0 ; i < -diff ; ++i ) {
373 ret = mkDeref( transUnit().global, ret );
374 }
375 // Must keep cast if types are different.
376 if ( !ResolvExpr::typesCompatibleIgnoreQualifiers(
377 dstType->stripReferences(),
378 srcType->stripReferences(),
379 ast::SymbolTable() ) ) {
380 return ast::mutate_field( expr, &ast::CastExpr::arg, ret );
381 }
382 ret->env = expr->env;
383 ret->result = expr->result;
384 // The result must be an lvalue.
385 assert( ret->get_lvalue() );
386 return ret;
387 // Conversion with the same depth.
388 } else {
389 assert( 0 == diff );
390 // Remove useless generated casts.
391 if ( expr->isGenerated &&
392 ResolvExpr::typesCompatible(
393 expr->result,
394 expr->arg->result, ast::SymbolTable() ) ) {
395 PRINT(
396 std::cerr << "types are compatible, removing cast: " << expr << '\n';
397 std::cerr << "-- " << expr->result << '\n';
398 std::cerr << "-- " << expr->arg->result << std::endl;
399 )
400 return ast::mutate_field( expr->arg.get(),
401 &ast::Expr::env, expr->env.get() );
402 }
403 return expr;
404 }
405}
406
407ast::Expr const * ReferenceConversions::postvisit(
408 ast::AddressExpr const * expr ) {
409 // Inner expression may have been lvalue to reference conversion, which
410 // becomes an address expression. In this case, remove the outer address
411 // expression and return the argument.
412 // TODO: It's possible that this might catch too much and require a more
413 // sophisticated check. TODO What check are we talking about here?
414 return expr;
415}
416
417ast::Expr const * FixIntrinsicArgs::postvisit(
418 ast::ApplicationExpr const * expr ) {
419 // Intrinsic functions don't really take reference-typed parameters,
420 // so they require an implicit dereference on their arguments.
421 auto function = ast::getFunction( expr );
422 if ( function == nullptr ) {
423 return expr;
424 }
425
426 ast::FunctionType const * ftype = GenPoly::getFunctionType( function->get_type() );
427 assertf( ftype, "Function declaration does not have function type." );
428 // Can be of different lengths only when function is variadic.
429 assertf( ftype->params.size() == expr->args.size() || ftype->isVarArgs,
430 "ApplicationExpr args do not match formal parameter type." );
431 assertf( ftype->params.size() <= expr->args.size(),
432 "Cannot have more parameters than arguments." );
433
434 unsigned int i = 0;
435 unsigned int const end = ftype->params.size();
436
437 // This is used to make sure we get a zip on shortests.
438 if ( end == i ) return expr;
439
440 // This mutate could be redundent, but it is simpler this way.
441 auto mutExpr = ast::mutate( expr );
442
443 for ( auto pair : unsafe_group_iterate( mutExpr->args, ftype->params ) ) {
444 ast::ptr<ast::Expr> & arg = std::get<0>( pair );
445 ast::ptr<ast::Type> const & formal = std::get<1>( pair );
446 PRINT(
447 std::cerr << "pair<0>: " << arg.get() << std::endl;
448 std::cerr << " -- " << arg->result << std::endl;
449 std::cerr << "pair<1>: " << formal << std::endl;
450 )
451 //if ( dynamic_cast<ast::ReferenceType const *>( formal.get() ) ) {
452 if ( formal.as<ast::ReferenceType>() ) {
453 PRINT( std::cerr << "===formal is reference" << std::endl; )
454 // TODO: It's likely that the second condition should be
455 // `... && ! isIntrinsicReference( arg )`, but this requires
456 // investigation.
457
458 if ( ast::Linkage::Intrinsic != function->linkage
459 && isIntrinsicReference( arg ) ) {
460 // Needed for definition of prelude functions, etc.
461 // If argument is dereference or array subscript, the result
462 // isn't REALLY a reference, but non-intrinsic functions
463 // expect a reference: take address
464
465 // TODO: OK, so this should be cut?!
466 // NODE: Previously, this condition fixed
467 // void f(int *&);
468 // int & x = ...;
469 // f(&x);
470 // But now this is taken care of by a reference cast added by
471 // AddressRef. Need to find a new example or remove this
472 // branch.
473 PRINT(
474 std::cerr << "===is intrinsic arg in non-intrinsic call - adding address" << std::endl;
475 )
476 arg = new ast::AddressExpr( arg->location, arg );
477 } else if ( ast::Linkage::Intrinsic == function->linkage
478 && arg->result->referenceDepth() != 0 ) {
479 // Argument is a 'real' reference, but function expects a C
480 // lvalue: Add a dereference to the reference-typed argument.
481 PRINT(
482 std::cerr << "===is non-intrinsic arg in intrinsic call - adding deref to arg" << std::endl;
483 )
484 ast::Type const * base = ast::getPointerBase( arg->result );
485 assertf( base, "parameter is reference, arg must be pointer or reference: %s", toString( arg->result ).c_str() );
486 ast::PointerType * ptr = new ast::PointerType( ast::deepCopy( base ) );
487 arg = ast::mutate_field( arg.get(),
488 &ast::ApplicationExpr::result, ptr );
489 arg = mkDeref( transUnit().global, arg );
490 }
491 }
492 ++i;
493 if ( end == i ) break;
494 }
495 return mutExpr;
496}
497
498ast::Expr const * CollapseAddressDeref::postvisit(
499 ast::AddressExpr const * expr ) {
500 ast::Expr const * arg = expr->arg;
501 if ( isIntrinsicReference( arg ) ) {
502 std::string fname = ast::getFunctionName( arg );
503 if ( fname == "*?" ) {
504 ast::Expr const * arg0 = ast::getCallArg( arg, 0 );
505 ast::Expr * ret = ast::mutate( arg0 );
506 ret->env = expr->env;
507 return ret;
508 }
509 } else if ( auto cast = dynamic_cast<ast::CastExpr const *>( arg ) ) {
510 // Need to move cast to pointer type out a level since address of
511 // pointer is not valid C code (can be introduced in prior passes,
512 // e.g., InstantiateGeneric)
513 if ( ast::getPointerBase( cast->result ) ) {
514 auto mutExpr = ast::mutate( expr );
515 auto mutCast = strict_dynamic_cast<ast::CastExpr *>(
516 ast::mutate( mutExpr->arg.release() ) );
517 mutExpr->arg = mutCast->arg;
518 mutCast->arg = mutExpr;
519 mutCast->result = new ast::PointerType( mutCast->result );
520 return mutCast;
521 }
522 }
523 return expr;
524}
525
526ast::Expr const * CollapseAddressDeref::postvisit(
527 ast::ApplicationExpr const * expr ) {
528 if ( isIntrinsicReference( expr ) ) {
529 std::string fname = ast::getFunctionName( expr );
530 if ( fname == "*?" ) {
531 assert( 1 == expr->args.size() );
532 ast::Expr const * arg = ast::getCallArg( expr, 0 );
533 // xxx - this isn't right, because it can remove casts that
534 // should be there...
535 // while ( auto cast = dynamic_cast< ast::CastExpr const * >( arg ) ) {
536 // arg = cast->arg;
537 // }
538 if ( auto addr = dynamic_cast<ast::AddressExpr const *>( arg ) ) {
539 return ast::mutate_field( addr->arg.get(),
540 &ast::Expr::env, expr->env.get() );
541 }
542 }
543 }
544 return expr;
545}
546
547ast::Expr const * GeneralizedLvalue::postvisit(
548 ast::AddressExpr const * expr ) {
549 return applyTransformation( expr, &ast::AddressExpr::arg,
550 []( ast::Expr const * arg ) {
551 return new ast::AddressExpr( arg->location, arg );
552 }
553 );
554}
555
556ast::Expr const * GeneralizedLvalue::postvisit(
557 ast::MemberExpr const * expr ) {
558 return applyTransformation( expr, &ast::MemberExpr::aggregate,
559 [expr]( ast::Expr const * aggr ) {
560 return new ast::MemberExpr( aggr->location, expr->member, aggr );
561 }
562 );
563}
564
565template<typename Node, typename Func>
566ast::Expr const * GeneralizedLvalue::applyTransformation(
567 Node const * expr, ast::ptr<ast::Expr> Node::*field, Func mkExpr ) {
568 ast::ptr<ast::Expr> const & arg = expr->*field;
569 if ( auto commaArg = arg.as<ast::CommaExpr>() ) {
570 ast::Expr const * arg1 = ast::deepCopy( commaArg->arg1 );
571 ast::Expr const * arg2 = ast::deepCopy( commaArg->arg2 );
572 ast::Expr const * ret = new ast::CommaExpr(
573 commaArg->location, arg1, mkExpr( arg2 )->accept( *visitor ) );
574 return ret;
575 } else if ( auto condArg = arg.as<ast::ConditionalExpr>() ) {
576 ast::Expr const * arg1 = ast::deepCopy( condArg->arg1 );
577 ast::Expr const * arg2 = ast::deepCopy( condArg->arg2 );
578 ast::Expr const * arg3 = ast::deepCopy( condArg->arg3 );
579 ast::ConditionalExpr * ret = new ast::ConditionalExpr(
580 condArg->location, arg1, mkExpr( arg2 )->accept( *visitor ),
581 mkExpr( arg3 )->accept( *visitor ) );
582
583 // Conditional expr type may not be either of the arguments,
584 // so unify to get the result.
585 // TODO: Maybe I could create a wrapper for this.
586 ast::ptr<ast::Type> common = nullptr;
587 ast::TypeEnvironment newEnv;
588 ast::AssertionSet needAssertions, haveAssertions;
589 ast::OpenVarSet openVars;
590 ResolvExpr::unify( ret->arg2->result, ret->arg3->result, newEnv,
591 needAssertions, haveAssertions, openVars,
592 ast::SymbolTable(), common );
593 ret->result = common ? common : ast::deepCopy( ret->arg2->result );
594 return ret;
595 }
596 return expr;
597}
598
599ast::Type const * ReferenceTypeElimination::postvisit(
600 ast::ReferenceType const * type ) {
601 return new ast::PointerType( type->base, type->qualifiers );
602}
603
604} // namespace
605
606// Stored elsewhere (Lvalue2, initially false):
607extern bool referencesEliminated;
608
609void convertLvalue( ast::TranslationUnit & translationUnit ) {
610 ast::Pass<FixIntrinsicResults>::run( translationUnit );
611 ast::Pass<AddressRef>::run( translationUnit );
612 ast::Pass<ReferenceConversions>::run( translationUnit );
613 ast::Pass<FixIntrinsicArgs>::run( translationUnit );
614 ast::Pass<CollapseAddressDeref>::run( translationUnit );
615 ast::Pass<GeneralizedLvalue>::run( translationUnit );
616 // Last because other passes need reference types to work.
617 ast::Pass<ReferenceTypeElimination>::run( translationUnit );
618 // From this point forward, nothing should create reference types.
619 referencesEliminated = true;
620}
621
622ast::Expr const * generalizedLvalue( ast::Expr const * expr ) {
623 ast::Pass<GeneralizedLvalue> visitor;
624 return expr->accept( visitor );
625}
626
627} // namespace GenPoly
628
629// Local Variables: //
630// tab-width: 4 //
631// mode: c++ //
632// compile-command: "make install" //
633// End: //
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