source: src/InitTweak/GenInit.cc@ 0e707bd

ADT arm-eh ast-experimental enum forall-pointer-decay jacob/cs343-translation new-ast-unique-expr pthread-emulation qualifiedEnum
Last change on this file since 0e707bd was 490fb92e, checked in by Fangren Yu <f37yu@…>, 5 years ago

move FixInit to new ast

  • Property mode set to 100644
File size: 17.6 KB
RevLine 
[51587aa]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//
[a0fdbd5]7// GenInit.cc --
[51587aa]8//
[cf16f94]9// Author : Rob Schluntz
[51587aa]10// Created On : Mon May 18 07:44:20 2015
[3a5131ed]11// Last Modified By : Peter A. Buhr
[07de76b]12// Last Modified On : Fri Dec 13 23:15:10 2019
13// Update Count : 184
[51587aa]14//
[8ca3a72]15#include "GenInit.h"
16
[2bfc6b2]17#include <stddef.h> // for NULL
18#include <algorithm> // for any_of
19#include <cassert> // for assert, strict_dynamic_cast, assertf
[b8524ca]20#include <deque>
[2bfc6b2]21#include <iterator> // for back_inserter, inserter, back_inse...
22#include <list> // for _List_iterator, list
[8ca3a72]23
[b8524ca]24#include "AST/Decl.hpp"
25#include "AST/Init.hpp"
26#include "AST/Node.hpp"
27#include "AST/Stmt.hpp"
[8135d4c]28#include "CodeGen/OperatorTable.h"
[2bfc6b2]29#include "Common/PassVisitor.h" // for PassVisitor, WithGuards, WithShort...
30#include "Common/SemanticError.h" // for SemanticError
31#include "Common/UniqueName.h" // for UniqueName
32#include "Common/utility.h" // for ValueGuard, maybeClone
33#include "GenPoly/GenPoly.h" // for getFunctionType, isPolyType
34#include "GenPoly/ScopedSet.h" // for ScopedSet, ScopedSet<>::const_iter...
35#include "InitTweak.h" // for isConstExpr, InitExpander, checkIn...
[fdd0509]36#include "ResolvExpr/Resolver.h"
[2bfc6b2]37#include "SymTab/Autogen.h" // for genImplicitCall
38#include "SymTab/Mangler.h" // for Mangler
[07de76b]39#include "SynTree/LinkageSpec.h" // for isOverridable, C
[2bfc6b2]40#include "SynTree/Declaration.h" // for ObjectDecl, DeclarationWithType
41#include "SynTree/Expression.h" // for VariableExpr, UntypedExpr, Address...
42#include "SynTree/Initializer.h" // for ConstructorInit, SingleInit, Initi...
43#include "SynTree/Label.h" // for Label
44#include "SynTree/Mutator.h" // for mutateAll
45#include "SynTree/Statement.h" // for CompoundStmt, ImplicitCtorDtorStmt
46#include "SynTree/Type.h" // for Type, ArrayType, Type::Qualifiers
47#include "SynTree/Visitor.h" // for acceptAll, maybeAccept
48#include "Tuples/Tuples.h" // for maybeImpure
49#include "Validate/FindSpecialDecls.h" // for SizeType
[42e2ad7]50
51namespace InitTweak {
[a08ba92]52 namespace {
53 const std::list<Label> noLabels;
[5b40f30]54 const std::list<Expression *> noDesignators;
[a08ba92]55 }
[1e9d87b]56
[d24d4e1]57 struct ReturnFixer : public WithStmtsToAdd, public WithGuards {
[a0fdbd5]58 /// consistently allocates a temporary variable for the return value
59 /// of a function so that anything which the resolver decides can be constructed
[02c7d04]60 /// into the return type of a function can be returned.
[a0fdbd5]61 static void makeReturnTemp( std::list< Declaration * > &translationUnit );
[02c7d04]62
[7b6ca2e]63 void premutate( FunctionDecl *functionDecl );
64 void premutate( ReturnStmt * returnStmt );
[1e9d87b]65
66 protected:
[c6976ba]67 FunctionType * ftype = nullptr;
[cf16f94]68 std::string funcName;
69 };
[42e2ad7]70
[22bc276]71 struct CtorDtor : public WithGuards, public WithShortCircuiting, public WithVisitorRef<CtorDtor> {
[02c7d04]72 /// create constructor and destructor statements for object declarations.
[5f98ce5]73 /// the actual call statements will be added in after the resolver has run
74 /// so that the initializer expression is only removed if a constructor is found
75 /// and the same destructor call is inserted in all of the appropriate locations.
[02c7d04]76 static void generateCtorDtor( std::list< Declaration * > &translationUnit );
[974906e2]77
[d24d4e1]78 void previsit( ObjectDecl * );
79 void previsit( FunctionDecl *functionDecl );
80
[5f98ce5]81 // should not traverse into any of these declarations to find objects
82 // that need to be constructed or destructed
[d24d4e1]83 void previsit( StructDecl *aggregateDecl );
[aec3e6b]84 void previsit( AggregateDecl * ) { visit_children = false; }
85 void previsit( NamedTypeDecl * ) { visit_children = false; }
[22bc276]86 void previsit( FunctionType * ) { visit_children = false; }
[db4ecc5]87
[d24d4e1]88 void previsit( CompoundStmt * compoundStmt );
[1ba88a0]89
90 private:
91 // set of mangled type names for which a constructor or destructor exists in the current scope.
92 // these types require a ConstructorInit node to be generated, anything else is a POD type and thus
93 // should not have a ConstructorInit generated.
94
[bfd4974]95 ManagedTypes managedTypes;
[1ba88a0]96 bool inFunction = false;
[974906e2]97 };
98
[fdd0509]99 struct HoistArrayDimension final : public WithDeclsToAdd, public WithShortCircuiting, public WithGuards, public WithIndexer {
[5f98ce5]100 /// hoist dimension from array types in object declaration so that it uses a single
101 /// const variable of type size_t, so that side effecting array dimensions are only
102 /// computed once.
103 static void hoistArrayDimension( std::list< Declaration * > & translationUnit );
104
[22bc276]105 void premutate( ObjectDecl * objectDecl );
106 DeclarationWithType * postmutate( ObjectDecl * objectDecl );
107 void premutate( FunctionDecl *functionDecl );
[5f98ce5]108 // should not traverse into any of these declarations to find objects
109 // that need to be constructed or destructed
[22bc276]110 void premutate( AggregateDecl * ) { visit_children = false; }
111 void premutate( NamedTypeDecl * ) { visit_children = false; }
112 void premutate( FunctionType * ) { visit_children = false; }
[5f98ce5]113
[fdd0509]114 // need this so that enumerators are added to the indexer, due to premutate(AggregateDecl *)
115 void premutate( EnumDecl * ) {}
116
[5f98ce5]117 void hoist( Type * type );
118
[68fe077a]119 Type::StorageClasses storageClasses;
[40e636a]120 bool inFunction = false;
[5f98ce5]121 };
122
[a0fdbd5]123 void genInit( std::list< Declaration * > & translationUnit ) {
[8b11840]124 fixReturnStatements( translationUnit );
[5f98ce5]125 HoistArrayDimension::hoistArrayDimension( translationUnit );
[02c7d04]126 CtorDtor::generateCtorDtor( translationUnit );
127 }
128
[8b11840]129 void fixReturnStatements( std::list< Declaration * > & translationUnit ) {
[7b6ca2e]130 PassVisitor<ReturnFixer> fixer;
[a0fdbd5]131 mutateAll( translationUnit, fixer );
[a08ba92]132 }
[42e2ad7]133
[7b6ca2e]134 void ReturnFixer::premutate( ReturnStmt *returnStmt ) {
[65660bd]135 std::list< DeclarationWithType * > & returnVals = ftype->get_returnVals();
[cf16f94]136 assert( returnVals.size() == 0 || returnVals.size() == 1 );
[c6976ba]137 // hands off if the function returns a reference - we don't want to allocate a temporary if a variable's address
[cf16f94]138 // is being returned
[bd7e609]139 if ( returnStmt->expr && returnVals.size() == 1 && isConstructable( returnVals.front()->get_type() ) ) {
[cce9429]140 // explicitly construct the return value using the return expression and the retVal object
[18ca28e]141 assertf( returnVals.front()->name != "", "Function %s has unnamed return value\n", funcName.c_str() );
[c6976ba]142
[bd7e609]143 ObjectDecl * retVal = strict_dynamic_cast< ObjectDecl * >( returnVals.front() );
144 if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( returnStmt->expr ) ) {
145 // return statement has already been mutated - don't need to do it again
146 if ( varExpr->var == retVal ) return;
147 }
[9fe33947]148 Statement * stmt = genCtorDtor( "?{}", retVal, returnStmt->expr );
149 assertf( stmt, "ReturnFixer: genCtorDtor returned nullptr: %s / %s", toString( retVal ).c_str(), toString( returnStmt->expr ).c_str() );
150 stmtsToAddBefore.push_back( stmt );
[cf16f94]151
[cce9429]152 // return the retVal object
[18ca28e]153 returnStmt->expr = new VariableExpr( returnVals.front() );
[cf16f94]154 } // if
155 }
156
[7b6ca2e]157 void ReturnFixer::premutate( FunctionDecl *functionDecl ) {
[4eb31f2b]158 GuardValue( ftype );
159 GuardValue( funcName );
[1e9d87b]160
[22bc276]161 ftype = functionDecl->type;
162 funcName = functionDecl->name;
[cf16f94]163 }
[974906e2]164
[4d2434a]165 // precompute array dimension expression, because constructor generation may duplicate it,
166 // which would be incorrect if it is a side-effecting computation.
[5f98ce5]167 void HoistArrayDimension::hoistArrayDimension( std::list< Declaration * > & translationUnit ) {
[22bc276]168 PassVisitor<HoistArrayDimension> hoister;
169 mutateAll( translationUnit, hoister );
[5f98ce5]170 }
171
[22bc276]172 void HoistArrayDimension::premutate( ObjectDecl * objectDecl ) {
173 GuardValue( storageClasses );
[a7c90d4]174 storageClasses = objectDecl->get_storageClasses();
[22bc276]175 }
176
177 DeclarationWithType * HoistArrayDimension::postmutate( ObjectDecl * objectDecl ) {
[5f98ce5]178 hoist( objectDecl->get_type() );
[22bc276]179 return objectDecl;
[5f98ce5]180 }
181
182 void HoistArrayDimension::hoist( Type * type ) {
[40e636a]183 // if in function, generate const size_t var
[5f98ce5]184 static UniqueName dimensionName( "_array_dim" );
[40e636a]185
[a7c90d4]186 // C doesn't allow variable sized arrays at global scope or for static variables, so don't hoist dimension.
[f9cebb5]187 if ( ! inFunction ) return;
[08d5507b]188 if ( storageClasses.is_static ) return;
[f9cebb5]189
190 if ( ArrayType * arrayType = dynamic_cast< ArrayType * >( type ) ) {
[5f98ce5]191 if ( ! arrayType->get_dimension() ) return; // xxx - recursive call to hoist?
192
[fdd0509]193 // need to resolve array dimensions in order to accurately determine if constexpr
[2bfc6b2]194 ResolvExpr::findSingleExpression( arrayType->dimension, Validate::SizeType->clone(), indexer );
[4e22d7d]195 // array is variable-length when the dimension is not constexpr
196 arrayType->isVarLen = ! isConstExpr( arrayType->dimension );
[300d75b]197 // don't need to hoist dimension if it's definitely pure - only need to if there's potential for side effects.
198 if ( ! Tuples::maybeImpure( arrayType->dimension ) ) return;
[5f98ce5]199
[2bfc6b2]200 ObjectDecl * arrayDimension = new ObjectDecl( dimensionName.newName(), storageClasses, LinkageSpec::C, 0, Validate::SizeType->clone(), new SingleInit( arrayType->get_dimension() ) );
[615a096]201 arrayDimension->get_type()->set_const( true );
[5f98ce5]202
203 arrayType->set_dimension( new VariableExpr( arrayDimension ) );
[22bc276]204 declsToAddBefore.push_back( arrayDimension );
[5f98ce5]205
206 hoist( arrayType->get_base() );
207 return;
208 }
209 }
[974906e2]210
[22bc276]211 void HoistArrayDimension::premutate( FunctionDecl * ) {
212 GuardValue( inFunction );
[fdd0509]213 inFunction = true;
[40e636a]214 }
215
[02c7d04]216 void CtorDtor::generateCtorDtor( std::list< Declaration * > & translationUnit ) {
[d24d4e1]217 PassVisitor<CtorDtor> ctordtor;
218 acceptAll( translationUnit, ctordtor );
[974906e2]219 }
220
[bfd4974]221 bool ManagedTypes::isManaged( Type * type ) const {
[22bc276]222 // references are never constructed
[c6976ba]223 if ( dynamic_cast< ReferenceType * >( type ) ) return false;
[0b465a5]224 // need to clear and reset qualifiers when determining if a type is managed
225 ValueGuard< Type::Qualifiers > qualifiers( type->get_qualifiers() );
226 type->get_qualifiers() = Type::Qualifiers();
[ac9ca96]227 if ( TupleType * tupleType = dynamic_cast< TupleType * > ( type ) ) {
228 // tuple is also managed if any of its components are managed
[22bc276]229 if ( std::any_of( tupleType->types.begin(), tupleType->types.end(), [&](Type * type) { return isManaged( type ); }) ) {
[ac9ca96]230 return true;
231 }
232 }
[30b65d8]233 // a type is managed if it appears in the map of known managed types, or if it contains any polymorphism (is a type variable or generic type containing a type variable)
[e35f30a]234 return managedTypes.find( SymTab::Mangler::mangleConcrete( type ) ) != managedTypes.end() || GenPoly::isPolyType( type );
[65660bd]235 }
236
[bfd4974]237 bool ManagedTypes::isManaged( ObjectDecl * objDecl ) const {
[1ba88a0]238 Type * type = objDecl->get_type();
239 while ( ArrayType * at = dynamic_cast< ArrayType * >( type ) ) {
[be9aa0f]240 // must always construct VLAs with an initializer, since this is an error in C
241 if ( at->isVarLen && objDecl->init ) return true;
[1ba88a0]242 type = at->get_base();
243 }
[65660bd]244 return isManaged( type );
[1ba88a0]245 }
246
[bfd4974]247 void ManagedTypes::handleDWT( DeclarationWithType * dwt ) {
[1ba88a0]248 // if this function is a user-defined constructor or destructor, mark down the type as "managed"
[bff227f]249 if ( ! LinkageSpec::isOverridable( dwt->get_linkage() ) && CodeGen::isCtorDtor( dwt->get_name() ) ) {
[1ba88a0]250 std::list< DeclarationWithType * > & params = GenPoly::getFunctionType( dwt->get_type() )->get_parameters();
251 assert( ! params.empty() );
[ce8c12f]252 Type * type = InitTweak::getPointerBase( params.front()->get_type() );
253 assert( type );
[e35f30a]254 managedTypes.insert( SymTab::Mangler::mangleConcrete( type ) );
[1ba88a0]255 }
256 }
257
[bfd4974]258 void ManagedTypes::handleStruct( StructDecl * aggregateDecl ) {
259 // don't construct members, but need to take note if there is a managed member,
260 // because that means that this type is also managed
261 for ( Declaration * member : aggregateDecl->get_members() ) {
262 if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) {
263 if ( isManaged( field ) ) {
[e35f30a]264 // generic parameters should not play a role in determining whether a generic type is constructed - construct all generic types, so that
265 // polymorphic constructors make generic types managed types
[bfd4974]266 StructInstType inst( Type::Qualifiers(), aggregateDecl );
[e35f30a]267 managedTypes.insert( SymTab::Mangler::mangleConcrete( &inst ) );
[bfd4974]268 break;
269 }
270 }
271 }
272 }
273
274 void ManagedTypes::beginScope() { managedTypes.beginScope(); }
275 void ManagedTypes::endScope() { managedTypes.endScope(); }
276
[092528b]277 ImplicitCtorDtorStmt * genCtorDtor( const std::string & fname, ObjectDecl * objDecl, Expression * arg ) {
278 // call into genImplicitCall from Autogen.h to generate calls to ctor/dtor
279 assertf( objDecl, "genCtorDtor passed null objDecl" );
280 std::list< Statement * > stmts;
[b8524ca]281 InitExpander_old srcParam( maybeClone( arg ) );
[092528b]282 SymTab::genImplicitCall( srcParam, new VariableExpr( objDecl ), fname, back_inserter( stmts ), objDecl );
283 assert( stmts.size() <= 1 );
[e3e16bc]284 return stmts.size() == 1 ? strict_dynamic_cast< ImplicitCtorDtorStmt * >( stmts.front() ) : nullptr;
[490fb92e]285
286 }
287
288 ast::ptr<ast::Stmt> genCtorDtor (const CodeLocation & loc, const std::string & fname, const ast::ObjectDecl * objDecl, const ast::Expr * arg) {
289 assertf(objDecl, "genCtorDtor passed null objDecl");
290 InitExpander_new srcParam(arg);
291 return SymTab::genImplicitCall(srcParam, new ast::VariableExpr(loc, objDecl), loc, fname, objDecl);
[092528b]292 }
293
[f0121d7]294 ConstructorInit * genCtorInit( ObjectDecl * objDecl ) {
295 // call into genImplicitCall from Autogen.h to generate calls to ctor/dtor
296 // for each constructable object
297 std::list< Statement * > ctor;
298 std::list< Statement * > dtor;
299
[b8524ca]300 InitExpander_old srcParam( objDecl->get_init() );
301 InitExpander_old nullParam( (Initializer *)NULL );
[f0121d7]302 SymTab::genImplicitCall( srcParam, new VariableExpr( objDecl ), "?{}", back_inserter( ctor ), objDecl );
303 SymTab::genImplicitCall( nullParam, new VariableExpr( objDecl ), "^?{}", front_inserter( dtor ), objDecl, false );
304
305 // Currently genImplicitCall produces a single Statement - a CompoundStmt
306 // which wraps everything that needs to happen. As such, it's technically
307 // possible to use a Statement ** in the above calls, but this is inherently
308 // unsafe, so instead we take the slightly less efficient route, but will be
309 // immediately informed if somehow the above assumption is broken. In this case,
310 // we could always wrap the list of statements at this point with a CompoundStmt,
311 // but it seems reasonable at the moment for this to be done by genImplicitCall
312 // itself. It is possible that genImplicitCall produces no statements (e.g. if
313 // an array type does not have a dimension). In this case, it's fine to ignore
314 // the object for the purposes of construction.
315 assert( ctor.size() == dtor.size() && ctor.size() <= 1 );
316 if ( ctor.size() == 1 ) {
317 // need to remember init expression, in case no ctors exist
318 // if ctor does exist, want to use ctor expression instead of init
319 // push this decision to the resolver
320 assert( dynamic_cast< ImplicitCtorDtorStmt * > ( ctor.front() ) && dynamic_cast< ImplicitCtorDtorStmt * > ( dtor.front() ) );
321 return new ConstructorInit( ctor.front(), dtor.front(), objDecl->get_init() );
322 }
323 return nullptr;
324 }
325
[d24d4e1]326 void CtorDtor::previsit( ObjectDecl * objDecl ) {
[bfd4974]327 managedTypes.handleDWT( objDecl );
[1ba88a0]328 // hands off if @=, extern, builtin, etc.
[a4dd728]329 // even if unmanaged, try to construct global or static if initializer is not constexpr, since this is not legal C
[bfd4974]330 if ( tryConstruct( objDecl ) && ( managedTypes.isManaged( objDecl ) || ((! inFunction || objDecl->get_storageClasses().is_static ) && ! isConstExpr( objDecl->get_init() ) ) ) ) {
[1ba88a0]331 // constructed objects cannot be designated
[a16764a6]332 if ( isDesignated( objDecl->get_init() ) ) SemanticError( objDecl, "Cannot include designations in the initializer for a managed Object. If this is really what you want, then initialize with @=.\n" );
[dcd73d1]333 // constructed objects should not have initializers nested too deeply
[a16764a6]334 if ( ! checkInitDepth( objDecl ) ) SemanticError( objDecl, "Managed object's initializer is too deep " );
[1ba88a0]335
[f0121d7]336 objDecl->set_init( genCtorInit( objDecl ) );
[974906e2]337 }
338 }
339
[d24d4e1]340 void CtorDtor::previsit( FunctionDecl *functionDecl ) {
[22bc276]341 visit_children = false; // do not try and construct parameters or forall parameters
[d24d4e1]342 GuardValue( inFunction );
[1ba88a0]343 inFunction = true;
344
[bfd4974]345 managedTypes.handleDWT( functionDecl );
[1ba88a0]346
[d24d4e1]347 GuardScope( managedTypes );
[1ba88a0]348 // go through assertions and recursively add seen ctor/dtors
[8c49c0e]349 for ( auto & tyDecl : functionDecl->get_functionType()->get_forall() ) {
[1ba88a0]350 for ( DeclarationWithType *& assertion : tyDecl->get_assertions() ) {
[bfd4974]351 managedTypes.handleDWT( assertion );
[1ba88a0]352 }
353 }
354
[22bc276]355 maybeAccept( functionDecl->get_statements(), *visitor );
[02c7d04]356 }
[1ba88a0]357
[d24d4e1]358 void CtorDtor::previsit( StructDecl *aggregateDecl ) {
359 visit_children = false; // do not try to construct and destruct aggregate members
360
[bfd4974]361 managedTypes.handleStruct( aggregateDecl );
[1ba88a0]362 }
363
[22bc276]364 void CtorDtor::previsit( CompoundStmt * ) {
[d24d4e1]365 GuardScope( managedTypes );
[1ba88a0]366 }
[234b1cb]367
[b8524ca]368ast::ConstructorInit * genCtorInit( const CodeLocation & loc, const ast::ObjectDecl * objDecl ) {
369 // call into genImplicitCall from Autogen.h to generate calls to ctor/dtor for each
370 // constructable object
371 InitExpander_new srcParam{ objDecl->init }, nullParam{ (const ast::Init *)nullptr };
372
373 ast::ptr< ast::Stmt > ctor = SymTab::genImplicitCall(
374 srcParam, new ast::VariableExpr{ loc, objDecl }, loc, "?{}", objDecl );
375 ast::ptr< ast::Stmt > dtor = SymTab::genImplicitCall(
376 nullParam, new ast::VariableExpr{ loc, objDecl }, loc, "^?{}", objDecl,
377 SymTab::LoopBackward );
378
379 // check that either both ctor and dtor are present, or neither
380 assert( (bool)ctor == (bool)dtor );
381
382 if ( ctor ) {
383 // need to remember init expression, in case no ctors exist. If ctor does exist, want to
384 // use ctor expression instead of init.
385 ctor.strict_as< ast::ImplicitCtorDtorStmt >();
386 dtor.strict_as< ast::ImplicitCtorDtorStmt >();
387
388 return new ast::ConstructorInit{ loc, ctor, dtor, objDecl->init };
389 }
390
[234b1cb]391 return nullptr;
392}
393
[42e2ad7]394} // namespace InitTweak
395
[51587aa]396// Local Variables: //
397// tab-width: 4 //
398// mode: c++ //
399// compile-command: "make install" //
400// End: //
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