source: src/ControlStruct/ExceptTranslate.cc@ 307a732

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 307a732 was 307a732, checked in by Andrew Beach <ajbeach@…>, 8 years ago

The exception handling code compilers and translates, but the translation crashes.
  • Property mode set to 100644
File size: 17.2 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// ExceptVisitor.cc --
8//
9// Author : Andrew Beach
10// Created On : Wed Jun 14 16:49:00 2017
11// Last Modified By : Andrew Beach
12// Last Modified On : Fri Jun 30 13:30:00 2017
13// Update Count : 1
14//
15
16#include "ExceptTranslate.h"
17#include "Common/PassVisitor.h"
18#include "SynTree/Statement.h"
19#include "SynTree/Declaration.h"
20#include "SynTree/Expression.h"
21#include "SynTree/Type.h"
22#include "SynTree/Attribute.h"
23
24namespace ControlStruct {
25
26 // This (large) section could probably be moved out of the class
27 // and be static helpers instead.
28
29 // Type(Qualifiers &, false, std::list<Attribute *> &)
30
31 // void (*function)();
32 static FunctionType try_func_t(Type::Qualifiers(), false);
33 // void (*function)(int, exception);
34 static FunctionType catch_func_t(Type::Qualifiers(), false);
35 // int (*function)(exception);
36 static FunctionType match_func_t(Type::Qualifiers(), false);
37 // bool (*function)(exception);
38 static FunctionType handle_func_t(Type::Qualifiers(), false);
39 // void (*function)(__attribute__((unused)) void *);
40 static FunctionType finally_func_t(Type::Qualifiers(), false);
41
42 static void init_func_types() {
43 static bool init_complete = false;
44 if (init_complete) {
45 return;
46 }
47 ObjectDecl index_obj(
48 "__handler_index",
49 Type::StorageClasses(),
50 LinkageSpec::Cforall,
51 /*bitfieldWidth*/ NULL,
52 new BasicType( emptyQualifiers, BasicType::SignedInt ),
53 /*init*/ NULL
54 );
55 ObjectDecl exception_obj(
56 "__exception_inst",
57 Type::StorageClasses(),
58 LinkageSpec::Cforall,
59 /*bitfieldWidth*/ NULL,
60 new PointerType(
61 emptyQualifiers,
62 new BasicType( emptyQualifiers, BasicType::SignedInt )
63 ),
64 /*init*/ NULL
65 );
66 ObjectDecl bool_obj(
67 "__ret_bool",
68 Type::StorageClasses(),
69 LinkageSpec::Cforall,
70 /*bitfieldWidth*/ NULL,
71 new BasicType(emptyQualifiers, BasicType::Bool),
72 /*init*/ NULL
73 );
74 ObjectDecl voidptr_obj(
75 "__hook",
76 Type::StorageClasses(),
77 LinkageSpec::Cforall,
78 NULL,
79 new PointerType(
80 emptyQualifiers,
81 new VoidType(
82 emptyQualifiers
83 ),
84 std::list<Attribute *>{new Attribute("unused")}
85 ),
86 NULL
87 );
88
89 catch_func_t.get_parameters().push_back( index_obj.clone() );
90 catch_func_t.get_parameters().push_back( exception_obj.clone() );
91 match_func_t.get_returnVals().push_back( index_obj.clone() );
92 match_func_t.get_parameters().push_back( exception_obj.clone() );
93 handle_func_t.get_returnVals().push_back( bool_obj.clone() );
94 handle_func_t.get_parameters().push_back( exception_obj.clone() );
95 finally_func_t.get_parameters().push_back( voidptr_obj.clone() );
96
97 init_complete = true;
98 }
99
100 // Buricratic Helpers (Not having to do with the paritular operation.)
101
102 typedef std::list<CatchStmt*> CatchList;
103
104 void split( CatchList& allHandlers, CatchList& terHandlers,
105 CatchList& resHandlers ) {
106 while ( !allHandlers.empty() ) {
107 CatchStmt * stmt = allHandlers.front();
108 allHandlers.pop_front();
109 if (CatchStmt::Terminate == stmt->get_kind()) {
110 terHandlers.push_back(stmt);
111 } else {
112 resHandlers.push_back(stmt);
113 }
114 }
115 }
116
117 template<typename T>
118 void free_all( std::list<T *> &list ) {
119 typename std::list<T *>::iterator it;
120 for ( it = list.begin() ; it != list.end() ; ++it ) {
121 delete *it;
122 }
123 list.clear();
124 }
125
126 void appendDeclStmt( CompoundStmt * block, Declaration * item ) {
127 block->push_back(new DeclStmt(noLabels, item));
128 }
129
130 Expression * nameOf( DeclarationWithType * decl ) {
131 return new VariableExpr( decl );
132 }
133
134 // ThrowStmt Mutation Helpers
135
136 Statement * create_given_throw(
137 const char * throwFunc, ThrowStmt * throwStmt ) {
138 // { int NAME = EXPR; throwFunc( &NAME ); }
139 CompoundStmt * result = new CompoundStmt( noLabels );
140 ObjectDecl * local = new ObjectDecl(
141 "__local_exception_copy",
142 Type::StorageClasses(),
143 LinkageSpec::Cforall,
144 NULL,
145 new BasicType( emptyQualifiers, BasicType::SignedInt ),
146 new SingleInit( throwStmt->get_expr() )
147 );
148 appendDeclStmt( result, local );
149 UntypedExpr * call = new UntypedExpr( new NameExpr( throwFunc ) );
150 call->get_args().push_back( new AddressExpr( nameOf( local ) ) );
151 result->push_back( new ExprStmt( throwStmt->get_labels(), call ) );
152 throwStmt->set_expr( nullptr );
153 delete throwStmt;
154 return result;
155 }
156
157 Statement * create_terminate_throw( ThrowStmt *throwStmt ) {
158 // { int NAME = EXPR; __throw_terminate( &NAME ); }
159 return create_given_throw( "__cfaehm__throw_termination", throwStmt );
160 }
161 Statement * create_terminate_rethrow( ThrowStmt *throwStmt ) {
162 // __rethrow_terminate();
163 assert( nullptr == throwStmt->get_expr() );
164 Statement * result = new ExprStmt(
165 throwStmt->get_labels(),
166 new UntypedExpr( new NameExpr( "__cfaehm__rethrow_termination" ) )
167 );
168 delete throwStmt;
169 return result;
170 }
171 Statement * create_resume_throw( ThrowStmt *throwStmt ) {
172 // __throw_resume( EXPR );
173 return create_given_throw( "__cfaehm__throw_resumption", throwStmt );
174 }
175 Statement * create_resume_rethrow( ThrowStmt *throwStmt ) {
176 // return false;
177 Statement * result = new ReturnStmt(
178 throwStmt->get_labels(),
179 new ConstantExpr( Constant::from_bool( false ) )
180 );
181 delete throwStmt;
182 return result;
183 }
184
185 // TryStmt Mutation Helpers
186
187 CompoundStmt * take_try_block( TryStmt *tryStmt ) {
188 CompoundStmt * block = tryStmt->get_block();
189 tryStmt->set_block( nullptr );
190 return block;
191 }
192 FunctionDecl * create_try_wrapper( CompoundStmt *body ) {
193
194 return new FunctionDecl( "try", Type::StorageClasses(),
195 LinkageSpec::Cforall, try_func_t.clone(), body );
196 }
197
198 FunctionDecl * create_terminate_catch( CatchList &handlers ) {
199 std::list<CaseStmt *> handler_wrappers;
200
201 FunctionType *func_type = catch_func_t.clone();
202 DeclarationWithType * index_obj = func_type->get_parameters().front();
203 // DeclarationWithType * except_obj = func_type->get_parameters().back();
204
205 // Index 1..{number of handlers}
206 int index = 0;
207 CatchList::iterator it = handlers.begin();
208 for ( ; it != handlers.end() ; ++it ) {
209 ++index;
210 CatchStmt * handler = *it;
211
212 // INTEGERconstant Version
213 // case `index`:
214 // {
215 // `handler.body`
216 // }
217 // return;
218 std::list<Statement *> caseBody;
219 caseBody.push_back( handler->get_body() );
220 handler->set_body( nullptr );
221 caseBody.push_back( new ReturnStmt( noLabels, nullptr ) );
222
223 handler_wrappers.push_back( new CaseStmt(
224 noLabels,
225 new ConstantExpr( Constant::from_int( index ) ),
226 caseBody
227 ) );
228 }
229 // TODO: Some sort of meaningful error on default perhaps?
230
231 std::list<Statement*> stmt_handlers;
232 while ( !handler_wrappers.empty() ) {
233 stmt_handlers.push_back( handler_wrappers.front() );
234 handler_wrappers.pop_front();
235 }
236
237 SwitchStmt * handler_lookup = new SwitchStmt(
238 noLabels,
239 nameOf( index_obj ),
240 stmt_handlers
241 );
242 CompoundStmt * body = new CompoundStmt( noLabels );
243 body->push_back( handler_lookup );
244
245 return new FunctionDecl("catch", Type::StorageClasses(),
246 LinkageSpec::Cforall, func_type, body);
247 }
248
249 // Create a single check from a moddified handler.
250 // except_obj is referenced, modded_handler will be freed.
251 CompoundStmt *create_single_matcher(
252 DeclarationWithType * except_obj, CatchStmt * modded_handler ) {
253 CompoundStmt * block = new CompoundStmt( noLabels );
254
255 // INTEGERconstant Version
256 assert( nullptr == modded_handler->get_decl() );
257 ConstantExpr * number =
258 dynamic_cast<ConstantExpr*>( modded_handler->get_cond() );
259 assert( number );
260 modded_handler->set_cond( nullptr );
261
262 Expression * cond;
263 {
264 std::list<Expression *> args;
265 args.push_back( number );
266
267 std::list<Expression *> rhs_args;
268 rhs_args.push_back( nameOf( except_obj ) );
269 Expression * rhs = new UntypedExpr(
270 new NameExpr( "*?" ), rhs_args );
271 args.push_back( rhs );
272
273 cond = new UntypedExpr( new NameExpr( "?==?" /*???*/), args );
274 }
275
276 if ( modded_handler->get_cond() ) {
277 cond = new LogicalExpr( cond, modded_handler->get_cond() );
278 }
279 block->push_back( new IfStmt( noLabels,
280 cond, modded_handler->get_body(), nullptr ) );
281
282 modded_handler->set_decl( nullptr );
283 modded_handler->set_cond( nullptr );
284 modded_handler->set_body( nullptr );
285 delete modded_handler;
286 return block;
287 }
288
289 FunctionDecl * create_terminate_match( CatchList &handlers ) {
290 CompoundStmt * body = new CompoundStmt( noLabels );
291
292 FunctionType * func_type = match_func_t.clone();
293 DeclarationWithType * except_obj = func_type->get_parameters().back();
294
295 // Index 1..{number of handlers}
296 int index = 0;
297 CatchList::iterator it;
298 for ( it = handlers.begin() ; it != handlers.end() ; ++it ) {
299 ++index;
300 CatchStmt * handler = *it;
301
302 // Body should have been taken by create_terminate_catch.
303 assert( nullptr == handler->get_body() );
304
305 // Create new body.
306 handler->set_body( new ReturnStmt( noLabels,
307 new ConstantExpr( Constant::from_int( index ) ) ) );
308
309 // Create the handler.
310 body->push_back( create_single_matcher( except_obj, handler ) );
311 *it = nullptr;
312 }
313
314 body->push_back( new ReturnStmt( noLabels, new ConstantExpr(
315 Constant::from_int( 0 ) ) ) );
316
317 return new FunctionDecl("match", Type::StorageClasses(),
318 LinkageSpec::Cforall, func_type, body);
319 }
320
321 CompoundStmt * create_terminate_caller(
322 FunctionDecl * try_wrapper,
323 FunctionDecl * terminate_catch,
324 FunctionDecl * terminate_match) {
325
326 UntypedExpr * caller = new UntypedExpr( new NameExpr(
327 "__cfaehm__try_terminate" ) );
328 std::list<Expression *>& args = caller->get_args();
329 args.push_back( nameOf( try_wrapper ) );
330 args.push_back( nameOf( terminate_catch ) );
331 args.push_back( nameOf( terminate_match ) );
332
333 CompoundStmt * callStmt = new CompoundStmt( noLabels );
334 callStmt->push_back( new ExprStmt( noLabels, caller ) );
335 return callStmt;
336 }
337
338 FunctionDecl * create_resume_handler( CatchList &handlers ) {
339 CompoundStmt * body = new CompoundStmt( noLabels );
340
341 FunctionType * func_type = match_func_t.clone();
342 DeclarationWithType * except_obj = func_type->get_parameters().back();
343
344 CatchList::iterator it;
345 for ( it = handlers.begin() ; it != handlers.end() ; ++it ) {
346 CatchStmt * handler = *it;
347
348 // Modifiy body.
349 CompoundStmt * handling_code =
350 dynamic_cast<CompoundStmt*>( handler->get_body() );
351 if ( ! handling_code ) {
352 handling_code = new CompoundStmt( noLabels );
353 handling_code->push_back( handler->get_body() );
354 }
355 handling_code->push_back( new ReturnStmt( noLabels,
356 new ConstantExpr( Constant::from_bool( false ) ) ) );
357 handler->set_body( handling_code );
358
359 // Create the handler.
360 body->push_back( create_single_matcher( except_obj, handler ) );
361 *it = nullptr;
362 }
363
364 return new FunctionDecl("handle", Type::StorageClasses(),
365 LinkageSpec::Cforall, func_type, body);
366 }
367
368 CompoundStmt * create_resume_wrapper(
369 StructDecl * node_decl,
370 Statement * wraps,
371 FunctionDecl * resume_handler ) {
372 CompoundStmt * body = new CompoundStmt( noLabels );
373
374 // struct __try_resume_node __resume_node
375 // __attribute__((cleanup( __cfaehm__try_resume_cleanup )));
376 // ** unwinding of the stack here could cause problems **
377 // ** however I don't think that can happen currently **
378 // __cfaehm__try_resume_setup( &__resume_node, resume_handler );
379
380 std::list< Attribute * > attributes;
381 {
382 std::list< Expression * > attr_params;
383 attr_params.push_back( new NameExpr(
384 "__cfaehm__try_resume_cleanup" ) );
385 attributes.push_back( new Attribute( "cleanup", attr_params ) );
386 }
387
388 ObjectDecl * obj = new ObjectDecl(
389 "__resume_node",
390 Type::StorageClasses(),
391 LinkageSpec::Cforall,
392 nullptr,
393 new StructInstType(
394 Type::Qualifiers(),
395 node_decl
396 ),
397 nullptr,
398 attributes
399 );
400 appendDeclStmt( body, obj );
401
402 UntypedExpr *setup = new UntypedExpr( new NameExpr(
403 "__cfaehm__try_resume_setup" ) );
404 setup->get_args().push_back( new AddressExpr( nameOf( obj ) ) );
405 setup->get_args().push_back( nameOf( resume_handler ) );
406
407 body->push_back( new ExprStmt( noLabels, setup ) );
408
409 body->push_back( wraps );
410 return body;
411 }
412
413 FunctionDecl * create_finally_wrapper( TryStmt * tryStmt ) {
414 FinallyStmt * finally = tryStmt->get_finally();
415 CompoundStmt * body = finally->get_block();
416 finally->set_block( nullptr );
417 delete finally;
418 tryStmt->set_finally( nullptr );
419
420 return new FunctionDecl("finally", Type::StorageClasses(),
421 LinkageSpec::Cforall, finally_func_t.clone(), body);
422 }
423
424 ObjectDecl * create_finally_hook(
425 StructDecl * hook_decl, FunctionDecl * finally_wrapper ) {
426 // struct __cfaehm__cleanup_hook __finally_hook
427 // __attribute__((cleanup( finally_wrapper )));
428
429 // Make Cleanup Attribute.
430 std::list< Attribute * > attributes;
431 {
432 std::list< Expression * > attr_params;
433 attr_params.push_back( nameOf( finally_wrapper ) );
434 attributes.push_back( new Attribute( "cleanup", attr_params ) );
435 }
436
437 return new ObjectDecl(
438 "__finally_hook",
439 Type::StorageClasses(),
440 LinkageSpec::Cforall,
441 nullptr,
442 new StructInstType(
443 emptyQualifiers,
444 hook_decl
445 ),
446 nullptr,
447 attributes
448 );
449 }
450
451
452 class ExceptionMutatorCore : public WithGuards {
453 enum Context { NoHandler, TerHandler, ResHandler };
454
455 // Also need to handle goto, break & continue.
456 // They need to be cut off in a ResHandler, until we enter another
457 // loop, switch or the goto stays within the function.
458
459 Context cur_context;
460
461 // We might not need this, but a unique base for each try block's
462 // generated functions might be nice.
463 //std::string curFunctionName;
464 //unsigned int try_count = 0;
465
466 StructDecl *node_decl;
467 StructDecl *hook_decl;
468
469 public:
470 ExceptionMutatorCore() :
471 cur_context(NoHandler),
472 node_decl(nullptr), hook_decl(nullptr)
473 {}
474
475 void premutate( CatchStmt *catchStmt );
476 void premutate( StructDecl *structDecl );
477 Statement * postmutate( ThrowStmt *throwStmt );
478 Statement * postmutate( TryStmt *tryStmt );
479 };
480
481 Statement * ExceptionMutatorCore::postmutate( ThrowStmt *throwStmt ) {
482 // Ignoring throwStmt->get_target() for now.
483 if ( ThrowStmt::Terminate == throwStmt->get_kind() ) {
484 if ( throwStmt->get_expr() ) {
485 return create_terminate_throw( throwStmt );
486 } else if ( TerHandler == cur_context ) {
487 return create_terminate_rethrow( throwStmt );
488 } else {
489 assertf(false, "Invalid throw in %s at %i\n",
490 throwStmt->location.filename.c_str(),
491 throwStmt->location.linenumber);
492 return nullptr;
493 }
494 } else {
495 if ( throwStmt->get_expr() ) {
496 return create_resume_throw( throwStmt );
497 } else if ( ResHandler == cur_context ) {
498 return create_resume_rethrow( throwStmt );
499 } else {
500 assertf(false, "Invalid throwResume in %s at %i\n",
501 throwStmt->location.filename.c_str(),
502 throwStmt->location.linenumber);
503 return nullptr;
504 }
505 }
506 }
507
508 Statement * ExceptionMutatorCore::postmutate( TryStmt *tryStmt ) {
509 assert( node_decl );
510 assert( hook_decl );
511
512 // Generate a prefix for the function names?
513
514 CompoundStmt * block = new CompoundStmt( noLabels );
515 CompoundStmt * inner = take_try_block( tryStmt );
516
517 if ( tryStmt->get_finally() ) {
518 // Define the helper function.
519 FunctionDecl * finally_block =
520 create_finally_wrapper( tryStmt );
521 appendDeclStmt( block, finally_block );
522 // Create and add the finally cleanup hook.
523 appendDeclStmt( block,
524 create_finally_hook( hook_decl, finally_block ) );
525 }
526
527 CatchList termination_handlers;
528 CatchList resumption_handlers;
529 split( tryStmt->get_catchers(),
530 termination_handlers, resumption_handlers );
531
532 if ( resumption_handlers.size() ) {
533 // Define the helper function.
534 FunctionDecl * resume_handler =
535 create_resume_handler( resumption_handlers );
536 appendDeclStmt( block, resume_handler );
537 // Prepare hooks
538 inner = create_resume_wrapper( node_decl, inner, resume_handler );
539 }
540
541 if ( termination_handlers.size() ) {
542 // Define the three helper functions.
543 FunctionDecl * try_wrapper = create_try_wrapper( inner );
544 appendDeclStmt( block, try_wrapper );
545 FunctionDecl * terminate_catch =
546 create_terminate_catch( termination_handlers );
547 appendDeclStmt( block, terminate_catch );
548 FunctionDecl * terminate_match =
549 create_terminate_match( termination_handlers );
550 appendDeclStmt( block, terminate_match );
551 // Build the call to the try wrapper.
552 inner = create_terminate_caller(
553 try_wrapper, terminate_catch, terminate_match );
554 }
555
556 // Embed the try block.
557 block->push_back( inner );
558
559 //free_all( termination_handlers );
560 //free_all( resumption_handlers );
561
562 return block;
563 }
564
565 void ExceptionMutatorCore::premutate( CatchStmt *catchStmt ) {
566 GuardValue( cur_context );
567 if ( CatchStmt::Terminate == catchStmt->get_kind() ) {
568 cur_context = TerHandler;
569 } else {
570 cur_context = ResHandler;
571 }
572 }
573
574 void ExceptionMutatorCore::premutate( StructDecl *structDecl ) {
575 if ( !structDecl->has_body() ) {
576 // Skip children?
577 return;
578 } else if ( structDecl->get_name() == "__cfaehm__try_resume_node" ) {
579 assert( nullptr == node_decl );
580 node_decl = structDecl;
581 } else if ( structDecl->get_name() == "__cfaehm__cleanup_hook" ) {
582 assert( nullptr == hook_decl );
583 hook_decl = structDecl;
584 }
585 // Later we might get the exception type as well.
586 }
587
588 void translateEHM( std::list< Declaration *> & translationUnit ) {
589 init_func_types();
590
591 PassVisitor<ExceptionMutatorCore> translator;
592 for ( Declaration * decl : translationUnit ) {
593 decl->acceptMutator( translator );
594 }
595 }
596}
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