source: src/Validate/GenericParameter.cpp@ 01ba701

ADT ast-experimental pthread-emulation
Last change on this file since 01ba701 was 11df881, checked in by Andrew Beach <ajbeach@…>, 3 years ago

Updated documentation on pre-resolver passes, moving code to headers instead of uses. Note that some comments were just copied over, I don't know if they are accurate.

  • Property mode set to 100644
File size: 9.7 KB
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1//
2// Cforall Version 1.0.0 Copyright (C) 2018 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// GenericParameter.hpp -- Generic parameter related passes.
8//
9// Author : Andrew Beach
10// Created On : Fri Mar 21 10:02:00 2022
11// Last Modified By : Andrew Beach
12// Last Modified On : Fri Apr 22 16:43:00 2022
13// Update Count : 1
14//
15
16#include "GenericParameter.hpp"
17
18#include "AST/Decl.hpp"
19#include "AST/Expr.hpp"
20#include "AST/ParseNode.hpp"
21#include "AST/Pass.hpp"
22#include "AST/TranslationUnit.hpp"
23#include "AST/Type.hpp"
24#include "Validate/NoIdSymbolTable.hpp"
25
26namespace Validate {
27
28namespace {
29
30// Test for special name on a generic parameter. Special treatment for the
31// special name is a bootstrapping hack. In most cases, the worlds of T's
32// and of N's don't overlap (normal treamtemt). The foundations in
33// array.hfa use tagging for both types and dimensions. Tagging treats
34// its subject parameter even more opaquely than T&, which assumes it is
35// possible to have a pointer/reference to such an object. Tagging only
36// seeks to identify the type-system resident at compile time. Both N's
37// and T's can make tags. The tag definition uses the special name, which
38// is treated as "an N or a T." This feature is not inteded to be used
39// outside of the definition and immediate uses of a tag.
40inline bool isReservedTysysIdOnlyName( const std::string & name ) {
41 // The name might be wrapped in __..._generic so check for that as well.
42 int foundAt = name.find("__CFA_tysys_id_only");
43 if (foundAt == 0) return true;
44 if (foundAt == 2 && name[0] == '_' && name[1] == '_') return true;
45 return false;
46}
47
48template< typename InstType >
49const InstType * validateGeneric(
50 const CodeLocation & location, const InstType * type ) {
51 const typename InstType::base_type * base = type->base.get();
52 if ( nullptr == base ) {
53 return type;
54 }
55
56 const std::vector<ast::ptr<ast::TypeDecl>> & params = base->params;
57 if ( params.empty() ) {
58 return type;
59 }
60
61 // I think I can move this check up, or it should check the result of
62 // the substuition.
63
64 auto mutType = ast::mutate( type );
65 std::vector<ast::ptr<ast::Expr>> & args = mutType->params;
66
67 // Quick check before we get into the real work.
68 if ( params.size() < args.size() ) {
69 SemanticError( location, type, "Too many type arguments in generic type " );
70 }
71
72 // Insert defaults arguments when a type argument is missing (currently
73 // only supports missing arguments at the end of the list).
74 // A substitution is used to ensure that defaults are replaced correctly:
75 // forall(otype T, otype alloc = heap_allocator(T)) struct vector;
76 // vector(int) v;
77 // After insertion of default values becomes:
78 // vector(int, heap_allocator(T))
79 // The substitution is built with T=int so the result is:
80 // vector(int, heap_allocator(int))
81
82 ast::TypeSubstitution sub;
83 // Build the substution:
84 auto paramIter = params.begin();
85 auto argIter = args.begin();
86 for ( ; paramIter != params.end() ; ++paramIter, ++argIter ) {
87 if ( argIter != args.end() ) {
88 if ( auto expr = argIter->as<ast::TypeExpr>() ) {
89 sub.add( paramIter->get(), ast::deepCopy( expr->type ) );
90 }
91 } else if ( const ast::Type * defaultType = (*paramIter)->init ) {
92 args.push_back( new ast::TypeExpr(
93 location, ast::deepCopy( defaultType ) ) );
94 sub.add( paramIter->get(), ast::deepCopy( defaultType ) );
95 argIter = std::prev( args.end() );
96 } else {
97 SemanticError( location, type, "Too few type arguments in generic type " );
98 }
99 assert( argIter != args.end() );
100 bool typeParamDeclared = (*paramIter)->kind != ast::TypeDecl::Dimension;
101 bool typeArgGiven;
102 if ( isReservedTysysIdOnlyName( (*paramIter)->name ) ) {
103 // Always match when declaration is reserved name, means "either".
104 typeArgGiven = typeParamDeclared;
105 } else {
106 typeArgGiven = argIter->as<ast::TypeExpr>();
107 }
108 if ( !typeParamDeclared && typeArgGiven ) {
109 SemanticError( location, type, "Type argument given for value parameter: " );
110 }
111 if ( typeParamDeclared && !typeArgGiven ) {
112 SemanticError( location, type, "Expression argument given for type parameter: " );
113 }
114 }
115
116 // Actually do the application:
117 auto result = sub.apply( mutType );
118 return result.node.release();
119}
120
121struct ValidateGenericParamsCore : public ast::WithGuards {
122 const CodeLocation * locationPtr = nullptr;
123
124 void previsit( const ast::ParseNode * node ) {
125 GuardValue( locationPtr ) = &node->location;
126 }
127
128 const ast::StructInstType * previsit( const ast::StructInstType * type ) {
129 assert( locationPtr );
130 return validateGeneric( *locationPtr, type );
131 }
132
133 const ast::UnionInstType * previsit( const ast::UnionInstType * type ) {
134 assert( locationPtr );
135 return validateGeneric( *locationPtr, type );
136 }
137};
138
139// --------------------------------------------------------------------------
140
141struct TranslateDimensionCore :
142 public WithNoIdSymbolTable, public ast::WithGuards {
143
144 // SUIT: Struct- or Union- InstType
145 // Situational awareness:
146 // array( float, [[currentExpr]] ) has visitingChildOfSUIT == true
147 // array( float, [[currentExpr]] - 1 ) has visitingChildOfSUIT == false
148 // size_t x = [[currentExpr]] has visitingChildOfSUIT == false
149 bool nextVisitedNodeIsChildOfSUIT = false;
150 bool visitingChildOfSUIT = false;
151 void changeState_ChildOfSUIT( bool newValue ) {
152 GuardValue( visitingChildOfSUIT ) = nextVisitedNodeIsChildOfSUIT;
153 GuardValue( nextVisitedNodeIsChildOfSUIT ) = newValue;
154 }
155
156 void previsit( const ast::StructInstType * ) {
157 changeState_ChildOfSUIT( true );
158 }
159 void previsit( const ast::UnionInstType * ) {
160 changeState_ChildOfSUIT( true );
161 }
162 void previsit( const ast::Node * ) {
163 changeState_ChildOfSUIT( false );
164 }
165
166 const ast::TypeDecl * postvisit( const ast::TypeDecl * decl );
167 const ast::Expr * postvisit( const ast::DimensionExpr * expr );
168 const ast::Expr * postvisit( const ast::Expr * expr );
169 const ast::Expr * postvisit( const ast::TypeExpr * expr );
170};
171
172const ast::TypeDecl * TranslateDimensionCore::postvisit(
173 const ast::TypeDecl * decl ) {
174 if ( decl->kind == ast::TypeDecl::Dimension ) {
175 auto mutDecl = ast::mutate( decl );
176 mutDecl->kind = ast::TypeDecl::Dtype;
177 if ( !isReservedTysysIdOnlyName( mutDecl->name ) ) {
178 mutDecl->sized = true;
179 }
180 return mutDecl;
181 }
182 return decl;
183}
184
185// Passing values as dimension arguments: array( float, 7 ) -> array( float, char[ 7 ] )
186// Consuming dimension parameters: size_t x = N - 1 ; -> size_t x = sizeof(N) - 1 ;
187// Intertwined reality: array( float, N ) -> array( float, N )
188// array( float, N - 1 ) -> array( float, char[ sizeof(N) - 1 ] )
189// Intertwined case 1 is not just an optimization.
190// Avoiding char[sizeof(-)] is necessary to enable the call of f to bind the value of N, in:
191// forall([N]) void f( array(float, N) & );
192// array(float, 7) a;
193// f(a);
194const ast::Expr * TranslateDimensionCore::postvisit(
195 const ast::DimensionExpr * expr ) {
196 // Expression `expr` is an occurrence of N in LHS of above examples.
197 // Look up the name that `expr` references.
198 // If we are in a struct body, then this reference can be to an entry of
199 // the stuct's forall list.
200 // Whether or not we are in a struct body, this reference can be to an
201 // entry of a containing function's forall list.
202 // If we are in a struct body, then the stuct's forall declarations are
203 // innermost (functions don't occur in structs).
204 // Thus, a potential struct's declaration is highest priority.
205 // A struct's forall declarations are already renamed with _generic_ suffix.
206 // Try that name variant first.
207
208 std::string useName = "__" + expr->name + "_generic_";
209 ast::TypeDecl * namedParamDecl = const_cast<ast::TypeDecl *>(
210 strict_dynamic_cast<const ast::TypeDecl *, nullptr >(
211 symtab.lookupType( useName ) ) );
212
213 if ( !namedParamDecl ) {
214 useName = expr->name;
215 namedParamDecl = const_cast<ast::TypeDecl *>( strict_dynamic_cast<const ast::TypeDecl *, nullptr >( symtab.lookupType( useName ) ) );
216 }
217
218 // Expect to find it always.
219 // A misspelled name would have been parsed as an identifier.
220 assertf( namedParamDecl, "Type-system-managed value name not found in symbol table" );
221
222 auto * refToDecl = new ast::TypeInstType( useName, namedParamDecl );
223
224 if ( visitingChildOfSUIT ) {
225 // As in postvisit( Expr * ), topmost expression needs a TypeExpr
226 // wrapper. But avoid ArrayType-Sizeof.
227 return new ast::TypeExpr( expr->location, refToDecl );
228 } else {
229 // the N occurrence is being used directly as a runtime value,
230 // if we are in a type instantiation, then the N is within a bigger value computation
231 return new ast::SizeofExpr( expr->location, refToDecl );
232 }
233}
234
235const ast::Expr * TranslateDimensionCore::postvisit(
236 const ast::Expr * expr ) {
237 // This expression is used as an argument to instantiate a type.
238 if ( visitingChildOfSUIT ) {
239 // DimensionExpr and TypeExpr should not reach here.
240 return new ast::TypeExpr( expr->location,
241 new ast::ArrayType(
242 new ast::BasicType( ast::BasicType::Char ),
243 expr,
244 ast::VariableLen,
245 ast::DynamicDim
246 )
247 );
248 }
249 return expr;
250}
251
252const ast::Expr * TranslateDimensionCore::postvisit(
253 const ast::TypeExpr * expr ) {
254 // Does nothing, except prevents matching ast::Expr (above).
255 return expr;
256}
257
258} // namespace
259
260void fillGenericParameters( ast::TranslationUnit & translationUnit ) {
261 ast::Pass<ValidateGenericParamsCore>::run( translationUnit );
262}
263
264void translateDimensionParameters( ast::TranslationUnit & translationUnit ) {
265 ast::Pass<TranslateDimensionCore>::run( translationUnit );
266}
267
268} // namespace Validate
269
270// Local Variables: //
271// tab-width: 4 //
272// mode: c++ //
273// compile-command: "make install" //
274// End: //
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