source: src/AST/Util.cpp@ 2a301ff

Last change on this file since 2a301ff was 14c0f7b, checked in by Andrew Beach <ajbeach@…>, 2 years ago

Added invariant to check that referenced declarations are in scope. This one took a while, I don't remember why forall pointer decay is involved.
  • Property mode set to 100644
File size: 10.1 KB
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1//
2// Cforall Version 1.0.0 Copyright (C) 2019 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// Util.cpp -- General utilities for working with the AST.
8//
9// Author : Andrew Beach
10// Created On : Wed Jan 19 9:46:00 2022
11// Last Modified By : Andrew Beach
12// Last Modified On : Wed May 11 16:16:00 2022
13// Update Count : 3
14//
15
16#include "Util.hpp"
17
18#include "Node.hpp"
19#include "ParseNode.hpp"
20#include "Pass.hpp"
21#include "TranslationUnit.hpp"
22#include "Common/utility.h"
23#include "GenPoly/ScopedSet.h"
24
25#include <vector>
26
27using GenPoly::ScopedSet;
28
29namespace ast {
30
31namespace {
32
33/// Check that ast::ptr/strong references do not form a cycle.
34struct NoStrongCyclesCore {
35 std::vector<const Node *> parents;
36
37 void previsit( const Node * node ) {
38 for ( auto & parent : parents ) {
39 assert( parent != node );
40 }
41 parents.push_back( node );
42 }
43
44 void postvisit( const Node * node ) {
45 assert( !parents.empty() );
46 assert( parents.back() == node );
47 parents.pop_back();
48 }
49};
50
51/// Check that every note that can has a set CodeLocation.
52void isCodeLocationSet( const ParseNode * node ) {
53 assert( node->location.isSet() );
54}
55
56void areLabelLocationsSet( const Stmt * stmt ) {
57 for ( const Label& label : stmt->labels ) {
58 assert( label.location.isSet() );
59 }
60}
61
62/// Make sure the reference counts are in a valid combination.
63void isStable( const Node * node ) {
64 assert( node->isStable() );
65}
66
67/// Check that a FunctionDecl is synchronized with it's FunctionType.
68void functionDeclMatchesType( const FunctionDecl * decl ) {
69 // The type is a cache of sorts, if it is missing that is only a
70 // problem if isTypeFixed is set.
71 if ( decl->isTypeFixed ) {
72 assert( decl->type );
73 } else if ( !decl->type ) {
74 return;
75 }
76
77 const FunctionType * type = decl->type;
78
79 // Check that `type->forall` corresponds with `decl->type_params`.
80 assert( type->forall.size() == decl->type_params.size() );
81 // Check that `type->assertions` corresponds with `decl->assertions`.
82 assert( type->assertions.size() == decl->assertions.size() );
83 // Check that `type->params` corresponds with `decl->params`.
84 assert( type->params.size() == decl->params.size() );
85 // Check that `type->returns` corresponds with `decl->returns`.
86 assert( type->returns.size() == decl->returns.size() );
87}
88
89/// Check that the MemberExpr has an aggregate type and matching member.
90void memberMatchesAggregate( const MemberExpr * expr ) {
91 const Type * aggrType = expr->aggregate->result->stripReferences();
92 const AggregateDecl * decl = nullptr;
93 if ( auto inst = dynamic_cast<const StructInstType *>( aggrType ) ) {
94 decl = inst->base;
95 } else if ( auto inst = dynamic_cast<const UnionInstType *>( aggrType ) ) {
96 decl = inst->base;
97 }
98 assertf( decl, "Aggregate of member not correct type." );
99
100 for ( auto aggrMember : decl->members ) {
101 if ( expr->member == aggrMember ) {
102 return;
103 }
104 }
105 assertf( false, "Member not found." );
106}
107
108/// Check for Floating Nodes:
109/// Every node should be reachable from a root (the TranslationUnit) via a
110/// chain of structural references (tracked with ptr). This cannot check all
111/// of that, it just checks if a given node's field has a strong reference.
112template<typename node_t, typename field_t>
113void noFloatingNode( const node_t * node, field_t node_t::*field_ptr ) {
114 const field_t & field = node->*field_ptr;
115 if ( nullptr == field ) return;
116 assertf( field->isManaged(), "Floating node found." );
117}
118
119struct InvariantCore {
120 // To save on the number of visits: this is a kind of composed core.
121 // None of the passes should make changes so ordering doesn't matter.
122 NoStrongCyclesCore no_strong_cycles;
123
124 void previsit( const Node * node ) {
125 no_strong_cycles.previsit( node );
126 isStable( node );
127 }
128
129 void previsit( const ParseNode * node ) {
130 previsit( (const Node *)node );
131 isCodeLocationSet( node );
132 }
133
134 void previsit( const FunctionDecl * node ) {
135 previsit( (const ParseNode *)node );
136 functionDeclMatchesType( node );
137 }
138
139 void previsit( const Stmt * node ) {
140 previsit( (const ParseNode *)node );
141 areLabelLocationsSet( node );
142 }
143
144 void previsit( const VariableExpr * node ) {
145 previsit( (const ParseNode *)node );
146 noFloatingNode( node, &VariableExpr::var );
147 }
148
149 void previsit( const MemberExpr * node ) {
150 previsit( (const ParseNode *)node );
151 memberMatchesAggregate( node );
152 }
153
154 void previsit( const StructInstType * node ) {
155 previsit( (const Node *)node );
156 noFloatingNode( node, &StructInstType::base );
157 }
158
159 void previsit( const UnionInstType * node ) {
160 previsit( (const Node *)node );
161 noFloatingNode( node, &UnionInstType::base );
162 }
163
164 void previsit( const EnumInstType * node ) {
165 previsit( (const Node *)node );
166 noFloatingNode( node, &EnumInstType::base );
167 }
168
169 void previsit( const TypeInstType * node ) {
170 previsit( (const Node *)node );
171 noFloatingNode( node, &TypeInstType::base );
172 }
173
174 void postvisit( const Node * node ) {
175 no_strong_cycles.postvisit( node );
176 }
177};
178
179/// Checks that referred to nodes are in scope.
180/// This checks many readonly pointers to see if the declaration they are
181/// referring to is in scope by the structural rules of code.
182// Any escapes marked with a bug should be removed once the bug is fixed.
183struct InScopeCore : public ast::WithShortCircuiting {
184 ScopedSet<DeclWithType const *> typedDecls;
185 ScopedSet<TypeDecl const *> typeDecls;
186 // These 3 are really hard to check, because uses that originally ref. at
187 // a forward declaration can be rewired to point a later full definition.
188 ScopedSet<StructDecl const *> structDecls;
189 ScopedSet<UnionDecl const *> unionDecls;
190 ScopedSet<EnumDecl const *> enumDecls;
191 ScopedSet<TraitDecl const *> traitDecls;
192
193 bool isInGlobal = false;
194
195 void beginScope() {
196 typedDecls.beginScope();
197 typeDecls.beginScope();
198 structDecls.beginScope();
199 unionDecls.beginScope();
200 enumDecls.beginScope();
201 traitDecls.beginScope();
202 }
203
204 void endScope() {
205 typedDecls.endScope();
206 typeDecls.endScope();
207 structDecls.endScope();
208 unionDecls.endScope();
209 enumDecls.endScope();
210 traitDecls.endScope();
211 }
212
213 void previsit( ApplicationExpr const * expr ) {
214 // All isInGlobal manipulation is just to isolate this check.
215 // The invalid compound literals lead to bad ctor/dtors. [#280]
216 VariableExpr const * func = nullptr;
217 CastExpr const * cast = nullptr;
218 VariableExpr const * arg = nullptr;
219 if ( isInGlobal
220 && 1 == expr->args.size()
221 && ( func = expr->func.as<VariableExpr>() )
222 && ( "?{}" == func->var->name || "^?{}" == func->var->name )
223 && ( cast = expr->args[0].as<CastExpr>() )
224 && ( arg = cast->arg.as<VariableExpr>() )
225 && isPrefix( arg->var->name, "_compLit" ) ) {
226 visit_children = false;
227 }
228 }
229
230 void previsit( VariableExpr const * expr ) {
231 if ( !expr->var ) return;
232 // bitwise assignment escape [#281]
233 if ( expr->var->location.isUnset() ) return;
234 assert( typedDecls.contains( expr->var ) );
235 }
236
237 void previsit( FunctionType const * type ) {
238 // This is to avoid checking the assertions, which can point at the
239 // function's declaration and not the enclosing function.
240 for ( auto type_param : type->forall ) {
241 if ( type_param->formal_usage ) {
242 visit_children = false;
243 // We could check non-assertion fields here.
244 }
245 }
246 }
247
248 void previsit( TypeInstType const * type ) {
249 if ( !type->base ) return;
250 assertf( type->base->isManaged(), "Floating Node" );
251
252 // bitwise assignment escape [#281]
253 if ( type->base->location.isUnset() ) return;
254 // Formal types can actually look at out of scope variables.
255 if ( type->formal_usage ) return;
256 assert( typeDecls.contains( type->base ) );
257 }
258
259 void previsit( TraitInstType const * type ) {
260 if ( !type->base ) return;
261 assert( traitDecls.contains( type->base ) );
262 }
263
264 void previsit( ObjectDecl const * decl ) {
265 typedDecls.insert( decl );
266 // There are some ill-formed compound literals. [#280]
267 // The only known problem cases are at the top level.
268 if ( isPrefix( decl->name, "_compLit" ) ) {
269 visit_children = false;
270 }
271 }
272
273 void previsit( FunctionDecl const * decl ) {
274 typedDecls.insert( decl );
275 beginScope();
276 for ( auto & type_param : decl->type_params ) {
277 typeDecls.insert( type_param );
278 }
279 for ( auto & assertion : decl->assertions ) {
280 typedDecls.insert( assertion );
281 }
282 for ( auto & param : decl->params ) {
283 typedDecls.insert( param );
284 }
285 for ( auto & ret : decl->returns ) {
286 typedDecls.insert( ret );
287 }
288 // No special handling of withExprs.
289
290 // Part of the compound literal escape. [#280]
291 if ( "__global_init__" == decl->name
292 || "__global_destroy__" == decl->name ) {
293 assert( !isInGlobal );
294 isInGlobal = true;
295 }
296 }
297
298 void postvisit( FunctionDecl const * decl ) {
299 endScope();
300 // Part of the compound literal escape. [#280]
301 if ( isInGlobal && ( "__global_init__" == decl->name
302 || "__global_destroy__" == decl->name ) ) {
303 isInGlobal = false;
304 }
305 }
306
307 void previsit( StructDecl const * decl ) {
308 structDecls.insert( decl );
309 beginScope();
310 for ( auto & type_param : decl->params ) {
311 typeDecls.insert( type_param );
312 }
313 }
314
315 void postvisit( StructDecl const * ) {
316 endScope();
317 }
318
319 void previsit( UnionDecl const * decl ) {
320 unionDecls.insert( decl );
321 beginScope();
322 for ( auto & type_param : decl->params ) {
323 typeDecls.insert( type_param );
324 }
325 }
326
327 void postvisit( UnionDecl const * ) {
328 endScope();
329 }
330
331 void previsit( EnumDecl const * decl ) {
332 enumDecls.insert( decl );
333 if ( ast::EnumDecl::EnumHiding::Visible == decl->hide ) {
334 for ( auto & member : decl->members ) {
335 typedDecls.insert( member.strict_as<ast::DeclWithType>() );
336 }
337 }
338 beginScope();
339 for ( auto & type_param : decl->params ) {
340 typeDecls.insert( type_param );
341 }
342 }
343
344 void postvisit( EnumDecl const * ) {
345 endScope();
346 }
347
348 void previsit( TraitDecl const * decl ) {
349 traitDecls.insert( decl );
350 beginScope();
351 for ( auto & type_param : decl->params ) {
352 typeDecls.insert( type_param );
353 }
354 }
355
356 void postvisit( TraitDecl const * ) {
357 endScope();
358 }
359
360 void previsit( Designation const * ) {
361 visit_children = false;
362 }
363};
364
365} // namespace
366
367void checkInvariants( TranslationUnit & transUnit ) {
368 Pass<InvariantCore>::run( transUnit );
369 Pass<InScopeCore>::run( transUnit );
370}
371
372} // namespace ast
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