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source: src/InitTweak/FixInit.cc@ cdd1695

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Last change on this file since cdd1695 was d7dc824, checked in by Thierry Delisle <tdelisle@…>, 8 years ago
Removed more warnings
Property mode set to `100644`
File size: 52.5 KB

Rev	Line
[71f4e4f]	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	// FixInit.h --
	8	//
	9	// Author : Rob Schluntz
	10	// Created On : Wed Jan 13 16:29:30 2016
[adcc065]	11	// Last Modified By : Peter A. Buhr
[615a096]	12	// Last Modified On : Fri Mar 17 09:13:47 2017
	13	// Update Count : 71
[71f4e4f]	14	//
	15
	16	#include <stack>
	17	#include <list>
[c2931ea]	18	#include <iterator>
	19	#include <algorithm>
[dc86541]	20	#include <unordered_map>
	21	#include <unordered_set>
[134322e]	22
[7b3f66b]	23	#include "InitTweak.h"
[092528b]	24	#include "GenInit.h"
[6cf27a07]	25	#include "FixInit.h"
	26	#include "FixGlobalInit.h"
[134322e]	27	#include "CodeGen/GenType.h" // for warning/error messages
	28	#include "Common/PassVisitor.h"
	29	#include "GenPoly/DeclMutator.h"
	30	#include "GenPoly/PolyMutator.h"
[db4ecc5]	31	#include "ResolvExpr/Resolver.h"
[845cedc]	32	#include "ResolvExpr/typeops.h"
[134322e]	33	#include "SymTab/Autogen.h"
	34	#include "SymTab/Indexer.h"
	35	#include "SynTree/AddStmtVisitor.h"
	36	#include "SynTree/Attribute.h"
[71f4e4f]	37	#include "SynTree/Declaration.h"
	38	#include "SynTree/Expression.h"
	39	#include "SynTree/Initializer.h"
	40	#include "SynTree/Mutator.h"
[134322e]	41	#include "SynTree/Statement.h"
	42	#include "SynTree/Type.h"
[8bf784a]	43	#include "Tuples/Tuples.h"
[71f4e4f]	44
[f0121d7]	45	bool ctordtorp = false; // print all debug
	46	bool ctorp = false; // print ctor debug
	47	bool cpctorp = false; // print copy ctor debug
	48	bool dtorp = false; // print dtor debug
[845cedc]	49	#define PRINT( text ) if ( ctordtorp ) { text }
[c2931ea]	50	#define CP_CTOR_PRINT( text ) if ( ctordtorp \|\| cpctorp ) { text }
	51	#define DTOR_PRINT( text ) if ( ctordtorp \|\| dtorp ) { text }
[845cedc]	52
[71f4e4f]	53	namespace InitTweak {
	54	namespace {
[31f379c]	55	typedef std::unordered_map< Expression , TypeSubstitution > EnvMap;
[597db97f]	56	typedef std::unordered_map< int, int > UnqCount;
[31f379c]	57
[134322e]	58	class InsertImplicitCalls {
[c2931ea]	59	public:
[adcc065]	60	/// wrap function application expressions as ImplicitCopyCtorExpr nodes so that it is easy to identify which
	61	/// function calls need their parameters to be copy constructed
[31f379c]	62	static void insert( std::list< Declaration * > & translationUnit, EnvMap & envMap );
[c2931ea]	63
[31f379c]	64	InsertImplicitCalls( EnvMap & envMap ) : envMap( envMap ) {}
[134322e]	65
	66	Expression * postmutate( ApplicationExpr * appExpr );
	67	void premutate( StmtExpr * stmtExpr );
[31f379c]	68
	69	// collects environments for relevant nodes
	70	EnvMap & envMap;
[134322e]	71	TypeSubstitution * env; //Magically populated by the PassVisitor
[c2931ea]	72	};
	73
[62e5546]	74	class ResolveCopyCtors final : public SymTab::Indexer {
[c2931ea]	75	public:
[adcc065]	76	/// generate temporary ObjectDecls for each argument and return value of each ImplicitCopyCtorExpr,
	77	/// generate/resolve copy construction expressions for each, and generate/resolve destructors for both
	78	/// arguments and return value temporaries
[597db97f]	79	static void resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap, UnqCount & unqCount );
[c2931ea]	80
[141b786]	81	typedef SymTab::Indexer Parent;
	82	using Parent::visit;
	83
[597db97f]	84	ResolveCopyCtors( const EnvMap & envMap, UnqCount & unqCount ) : envMap( envMap ), unqCount( unqCount ) {}
[31f379c]	85
[62e5546]	86	virtual void visit( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
[31f379c]	87	virtual void visit( UniqueExpr * unqExpr ) override;
	88	virtual void visit( StmtExpr * stmtExpr ) override;
[c2931ea]	89
	90	/// create and resolve ctor/dtor expression: fname(var, [cpArg])
[65660bd]	91	Expression * makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg = NULL );
[c2931ea]	92	/// true if type does not need to be copy constructed to ensure correctness
[1132b62]	93	bool skipCopyConstruct( Type * type );
	94	void copyConstructArg( Expression & arg, ImplicitCopyCtorExpr impCpCtorExpr );
[092528b]	95	void destructRet( ObjectDecl * ret, ImplicitCopyCtorExpr * impCpCtorExpr );
[31f379c]	96
[c2931ea]	97	TypeSubstitution * env;
[31f379c]	98	const EnvMap & envMap;
[597db97f]	99	UnqCount & unqCount; // count the number of times each unique expr ID appears
[c2931ea]	100	};
	101
	102	/// collects constructed object decls - used as a base class
	103	class ObjDeclCollector : public AddStmtVisitor {
	104	public:
	105	typedef AddStmtVisitor Parent;
	106	using Parent::visit;
	107	typedef std::set< ObjectDecl * > ObjectSet;
[62e5546]	108	virtual void visit( CompoundStmt *compoundStmt ) override;
	109	virtual void visit( DeclStmt *stmt ) override;
[52c14b3]	110
	111	// don't go into other functions
[7e003011]	112	virtual void visit( __attribute__((unused)) FunctionDecl *decl ) override {}
[52c14b3]	113
[c2931ea]	114	protected:
	115	ObjectSet curVars;
	116	};
	117
[6cf27a07]	118	// debug
[c2931ea]	119	struct printSet {
	120	typedef ObjDeclCollector::ObjectSet ObjectSet;
	121	printSet( const ObjectSet & objs ) : objs( objs ) {}
	122	const ObjectSet & objs;
	123	};
	124	std::ostream & operator<<( std::ostream & out, const printSet & set) {
	125	out << "{ ";
	126	for ( ObjectDecl * obj : set.objs ) {
	127	out << obj->get_name() << ", " ;
[adcc065]	128	} // for
[c2931ea]	129	out << " }";
	130	return out;
	131	}
	132
[62e5546]	133	class LabelFinder final : public ObjDeclCollector {
[c2931ea]	134	public:
	135	typedef ObjDeclCollector Parent;
	136	typedef std::map< Label, ObjectSet > LabelMap;
	137	// map of Label -> live variables at that label
	138	LabelMap vars;
	139
	140	void handleStmt( Statement * stmt );
	141
	142	// xxx - This needs to be done better.
[adcc065]	143	// allow some generalization among different kinds of nodes with with similar parentage (e.g. all
	144	// expressions, all statements, etc.) important to have this to provide a single entry point so that as new
	145	// subclasses are added, there is only one place that the code has to be updated, rather than ensure that
	146	// every specialized class knows about every new kind of statement that might be added.
[62e5546]	147	using Parent::visit;
	148	virtual void visit( CompoundStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	149	virtual void visit( ExprStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	150	virtual void visit( AsmStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	151	virtual void visit( IfStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	152	virtual void visit( WhileStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	153	virtual void visit( ForStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	154	virtual void visit( SwitchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	155	virtual void visit( CaseStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	156	virtual void visit( BranchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	157	virtual void visit( ReturnStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	158	virtual void visit( TryStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	159	virtual void visit( CatchStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	160	virtual void visit( FinallyStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	161	virtual void visit( NullStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	162	virtual void visit( DeclStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
	163	virtual void visit( ImplicitCtorDtorStmt *stmt ) override { handleStmt( stmt ); return Parent::visit( stmt ); }
[c2931ea]	164	};
	165
[62e5546]	166	class InsertDtors final : public ObjDeclCollector {
[c2931ea]	167	public:
[adcc065]	168	/// insert destructor calls at the appropriate places. must happen before CtorInit nodes are removed
	169	/// (currently by FixInit)
[c2931ea]	170	static void insert( std::list< Declaration * > & translationUnit );
	171
	172	typedef ObjDeclCollector Parent;
	173	typedef std::list< ObjectDecl * > OrderedDecls;
	174	typedef std::list< OrderedDecls > OrderedDeclsStack;
	175
[52c14b3]	176	InsertDtors( LabelFinder & finder ) : finder( finder ), labelVars( finder.vars ) {}
[c2931ea]	177
[62e5546]	178	using Parent::visit;
	179
	180	virtual void visit( ObjectDecl * objDecl ) override;
[52c14b3]	181	virtual void visit( FunctionDecl * funcDecl ) override;
[c2931ea]	182
[62e5546]	183	virtual void visit( CompoundStmt * compoundStmt ) override;
	184	virtual void visit( ReturnStmt * returnStmt ) override;
	185	virtual void visit( BranchStmt * stmt ) override;
[c2931ea]	186	private:
	187	void handleGoto( BranchStmt * stmt );
	188
[52c14b3]	189	LabelFinder & finder;
[c2931ea]	190	LabelFinder::LabelMap & labelVars;
	191	OrderedDeclsStack reverseDeclOrder;
	192	};
	193
[aff3af4]	194	class FixInit {
[c2931ea]	195	public:
	196	/// expand each object declaration to use its constructor after it is declared.
	197	static void fixInitializers( std::list< Declaration * > &translationUnit );
	198
[aff3af4]	199	DeclarationWithType * postmutate( ObjectDecl *objDecl );
[72e9222]	200
	201	std::list< Declaration * > staticDtorDecls;
[aff3af4]	202	std::list< Statement * > stmtsToAddAfter; // found by PassVisitor
[c2931ea]	203	};
	204
[62e5546]	205	class FixCopyCtors final : public GenPoly::PolyMutator {
[c2931ea]	206	public:
[597db97f]	207	FixCopyCtors( UnqCount & unqCount ) : unqCount( unqCount ){}
[adcc065]	208	/// expand ImplicitCopyCtorExpr nodes into the temporary declarations, copy constructors, call expression,
	209	/// and destructors
[597db97f]	210	static void fixCopyCtors( std::list< Declaration * > &translationUnit, UnqCount & unqCount );
[c2931ea]	211
[31f379c]	212	typedef GenPoly::PolyMutator Parent;
	213	using Parent::mutate;
[62e5546]	214	virtual Expression * mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) override;
[b726084]	215	virtual Expression * mutate( UniqueExpr * unqExpr ) override;
[31f379c]	216	virtual Expression * mutate( StmtExpr * stmtExpr ) override;
[597db97f]	217
	218	UnqCount & unqCount;
[c2931ea]	219	};
[79970ed]	220
[62e5546]	221	class GenStructMemberCalls final : public SymTab::Indexer {
[79970ed]	222	public:
[c8dfcd3]	223	typedef Indexer Parent;
	224	/// generate default/copy ctor and dtor calls for user-defined struct ctor/dtors
	225	/// for any member that is missing a corresponding ctor/dtor call.
	226	/// error if a member is used before constructed
	227	static void generate( std::list< Declaration * > & translationUnit );
[79970ed]	228
[62e5546]	229	using Parent::visit;
	230
	231	virtual void visit( FunctionDecl * funcDecl ) override;
[79970ed]	232
[62e5546]	233	virtual void visit( MemberExpr * memberExpr ) override;
	234	virtual void visit( ApplicationExpr * appExpr ) override;
[79970ed]	235
[3906301]	236	SemanticError errors;
[79970ed]	237	private:
	238	void handleFirstParam( Expression * firstParam );
[3906301]	239	template< typename... Params >
[64ac636]	240	void emit( CodeLocation, const Params &... params );
[79970ed]	241
	242	FunctionDecl * function = 0;
[64ac636]	243	std::set< DeclarationWithType * > unhandled;
	244	std::map< DeclarationWithType *, CodeLocation > usedUninit;
[79970ed]	245	ObjectDecl * thisParam = 0;
[c8dfcd3]	246	bool isCtor = false; // true if current function is a constructor
[44f6341]	247	StructDecl * structDecl = 0;
[c8dfcd3]	248	};
	249
	250	// very simple resolver-like mutator class - used to
	251	// resolve UntypedExprs that are found within newly
	252	// generated constructor/destructor calls
[62e5546]	253	class MutatingResolver final : public Mutator {
[c8dfcd3]	254	public:
	255	MutatingResolver( SymTab::Indexer & indexer ) : indexer( indexer ) {}
	256
[62e5546]	257	using Mutator::mutate;
	258	virtual DeclarationWithType* mutate( ObjectDecl *objectDecl ) override;
	259	virtual Expression* mutate( UntypedExpr *untypedExpr ) override;
[c8dfcd3]	260
[62e5546]	261	private:
[c8dfcd3]	262	SymTab::Indexer & indexer;
[79970ed]	263	};
[b6fe7e6]	264
[62e5546]	265	class FixCtorExprs final : public GenPoly::DeclMutator {
[b6fe7e6]	266	public:
	267	/// expands ConstructorExpr nodes into comma expressions, using a temporary for the first argument
	268	static void fix( std::list< Declaration * > & translationUnit );
	269
[62e5546]	270	using GenPoly::DeclMutator::mutate;
	271	virtual Expression * mutate( ConstructorExpr * ctorExpr ) override;
[b6fe7e6]	272	};
[c2931ea]	273	} // namespace
[db4ecc5]	274
[6cf27a07]	275	void fix( std::list< Declaration * > & translationUnit, const std::string & filename, bool inLibrary ) {
	276	// fixes ConstructorInit for global variables. should happen before fixInitializers.
	277	InitTweak::fixGlobalInit( translationUnit, filename, inLibrary );
	278
[31f379c]	279	EnvMap envMap;
[597db97f]	280	UnqCount unqCount;
[b6fe7e6]	281
[31f379c]	282	InsertImplicitCalls::insert( translationUnit, envMap );
[597db97f]	283	ResolveCopyCtors::resolveImplicitCalls( translationUnit, envMap, unqCount );
[c2931ea]	284	InsertDtors::insert( translationUnit );
[71f4e4f]	285	FixInit::fixInitializers( translationUnit );
[c2931ea]	286
[db4ecc5]	287	// FixCopyCtors must happen after FixInit, so that destructors are placed correctly
[597db97f]	288	FixCopyCtors::fixCopyCtors( translationUnit, unqCount );
[79970ed]	289
[c8dfcd3]	290	GenStructMemberCalls::generate( translationUnit );
[b6fe7e6]	291	// xxx - ctor expansion currently has to be after FixCopyCtors, because there is currently a
	292	// hack in the way untyped assignments are generated, where the first argument cannot have
	293	// its address taken because of the way codegeneration handles UntypedExpr vs. ApplicationExpr.
	294	// Thus such assignment exprs must never pushed through expression resolution (and thus should
	295	// not go through the FixCopyCtors pass), otherwise they will fail -- guaranteed.
	296	// Also needs to happen after GenStructMemberCalls, since otherwise member constructors exprs
	297	// don't look right, and a member can be constructed more than once.
	298	FixCtorExprs::fix( translationUnit );
[db4ecc5]	299	}
	300
[c2931ea]	301	namespace {
[31f379c]	302	void InsertImplicitCalls::insert( std::list< Declaration * > & translationUnit, EnvMap & envMap ) {
[134322e]	303	PassVisitor<InsertImplicitCalls> inserter( envMap );
[c2931ea]	304	mutateAll( translationUnit, inserter );
	305	}
[db4ecc5]	306
[597db97f]	307	void ResolveCopyCtors::resolveImplicitCalls( std::list< Declaration * > & translationUnit, const EnvMap & envMap, UnqCount & unqCount ) {
	308	ResolveCopyCtors resolver( envMap, unqCount );
[c2931ea]	309	acceptAll( translationUnit, resolver );
	310	}
[71f4e4f]	311
[c2931ea]	312	void FixInit::fixInitializers( std::list< Declaration * > & translationUnit ) {
[aff3af4]	313	PassVisitor<FixInit> fixer;
[72e9222]	314
	315	// can't use mutateAll, because need to insert declarations at top-level
	316	// can't use DeclMutator, because sometimes need to insert IfStmt, etc.
	317	SemanticError errors;
	318	for ( std::list< Declaration * >::iterator i = translationUnit.begin(); i != translationUnit.end(); ++i ) {
	319	try {
	320	i = maybeMutate( i, fixer );
[aff3af4]	321	translationUnit.splice( i, fixer.pass.staticDtorDecls );
[72e9222]	322	} catch( SemanticError &e ) {
[138e29e]	323	e.set_location( (*i)->location );
[72e9222]	324	errors.append( e );
	325	} // try
	326	} // for
	327	if ( ! errors.isEmpty() ) {
	328	throw errors;
	329	} // if
[c2931ea]	330	}
[71f4e4f]	331
[c2931ea]	332	void InsertDtors::insert( std::list< Declaration * > & translationUnit ) {
	333	LabelFinder finder;
	334	InsertDtors inserter( finder );
	335	acceptAll( translationUnit, inserter );
	336	}
	337
[597db97f]	338	void FixCopyCtors::fixCopyCtors( std::list< Declaration * > & translationUnit, UnqCount & unqCount ) {
	339	FixCopyCtors fixer( unqCount );
[c2931ea]	340	mutateAll( translationUnit, fixer );
	341	}
[db4ecc5]	342
[c8dfcd3]	343	void GenStructMemberCalls::generate( std::list< Declaration * > & translationUnit ) {
	344	GenStructMemberCalls warner;
	345	acceptAll( translationUnit, warner );
[79970ed]	346	}
	347
[b6fe7e6]	348	void FixCtorExprs::fix( std::list< Declaration * > & translationUnit ) {
	349	FixCtorExprs fixer;
	350	fixer.mutateDeclarationList( translationUnit );
	351	}
	352
[134322e]	353	Expression * InsertImplicitCalls::postmutate( ApplicationExpr * appExpr ) {
[c2931ea]	354	assert( appExpr );
	355
	356	if ( VariableExpr * function = dynamic_cast< VariableExpr * > ( appExpr->get_function() ) ) {
[9a063c8]	357	if ( LinkageSpec::isBuiltin( function->get_var()->get_linkage() ) ) {
[c2931ea]	358	// optimization: don't need to copy construct in order to call intrinsic functions
	359	return appExpr;
	360	} else if ( DeclarationWithType * funcDecl = dynamic_cast< DeclarationWithType * > ( function->get_var() ) ) {
	361	FunctionType * ftype = dynamic_cast< FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) );
	362	assert( ftype );
[a28bc02]	363	if ( isConstructor( funcDecl->get_name() ) && ftype->get_parameters().size() == 2 ) {
[c2931ea]	364	Type * t1 = ftype->get_parameters().front()->get_type();
	365	Type * t2 = ftype->get_parameters().back()->get_type();
[31f379c]	366	PointerType * ptrType = safe_dynamic_cast< PointerType * > ( t1 );
[c2931ea]	367
	368	if ( ResolvExpr::typesCompatible( ptrType->get_base(), t2, SymTab::Indexer() ) ) {
[a28bc02]	369	// optimization: don't need to copy construct in order to call a copy constructor
[c2931ea]	370	return appExpr;
[adcc065]	371	} // if
[79970ed]	372	} else if ( isDestructor( funcDecl->get_name() ) ) {
[c2931ea]	373	// correctness: never copy construct arguments to a destructor
[845cedc]	374	return appExpr;
[adcc065]	375	} // if
	376	} // if
	377	} // if
[c2931ea]	378	CP_CTOR_PRINT( std::cerr << "InsertImplicitCalls: adding a wrapper " << appExpr << std::endl; )
	379
	380	// wrap each function call so that it is easy to identify nodes that have to be copy constructed
	381	ImplicitCopyCtorExpr * expr = new ImplicitCopyCtorExpr( appExpr );
[31f379c]	382	// save the type substitution into the envMap so that it is easy to find.
[c2931ea]	383	// Ensure it is not deleted with the ImplicitCopyCtorExpr by removing it before deletion.
	384	// The substitution is needed to obtain the type of temporary variables so that copy constructor
	385	// calls can be resolved. Normally this is what PolyMutator is for, but the pass that resolves
	386	// copy constructor calls must be an Indexer. We could alternatively make a PolyIndexer which
	387	// saves the environment, or compute the types of temporaries here, but it's much simpler to
	388	// save the environment here, and more cohesive to compute temporary variables and resolve copy
	389	// constructor calls together.
	390	assert( env );
[31f379c]	391	envMap[expr] = env;
[c2931ea]	392	return expr;
[db4ecc5]	393	}
	394
[134322e]	395	void InsertImplicitCalls::premutate( StmtExpr * stmtExpr ) {
[31f379c]	396	assert( env );
	397	envMap[stmtExpr] = env;
	398	}
	399
[c2931ea]	400	bool ResolveCopyCtors::skipCopyConstruct( Type * type ) {
[8bf784a]	401	return dynamic_cast< VarArgsType * >( type ) \|\| GenPoly::getFunctionType( type ) \|\| Tuples::isTtype( type );
[c2931ea]	402	}
	403
[65660bd]	404	Expression * ResolveCopyCtors::makeCtorDtor( const std::string & fname, ObjectDecl * var, Expression * cpArg ) {
[c2931ea]	405	assert( var );
[092528b]	406	// arrays are not copy constructed, so this should always be an ExprStmt
	407	ImplicitCtorDtorStmt * stmt = genCtorDtor( fname, var, cpArg );
	408	ExprStmt * exprStmt = safe_dynamic_cast< ExprStmt * >( stmt->get_callStmt() );
	409	Expression * untyped = exprStmt->get_expr();
[c2931ea]	410
	411	// resolve copy constructor
[adcc065]	412	// should only be one alternative for copy ctor and dtor expressions, since all arguments are fixed
	413	// (VariableExpr and already resolved expression)
[c2931ea]	414	CP_CTOR_PRINT( std::cerr << "ResolvingCtorDtor " << untyped << std::endl; )
[65660bd]	415	Expression * resolved = ResolvExpr::findVoidExpression( untyped, *this );
	416	assert( resolved );
[c2931ea]	417	if ( resolved->get_env() ) {
[31f379c]	418	// Extract useful information and discard new environments. Keeping them causes problems in PolyMutator passes.
[c2931ea]	419	env->add( *resolved->get_env() );
[31f379c]	420	delete resolved->get_env();
	421	resolved->set_env( nullptr );
[adcc065]	422	} // if
[cf18eea]	423
[092528b]	424	delete stmt;
[c2931ea]	425	return resolved;
[540de412]	426	}
[db4ecc5]	427
[1132b62]	428	void ResolveCopyCtors::copyConstructArg( Expression & arg, ImplicitCopyCtorExpr impCpCtorExpr ) {
[c2931ea]	429	static UniqueName tempNamer("_tmp_cp");
[31f379c]	430	assert( env );
	431	CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *env << std::endl; )
[1132b62]	432	assert( arg->has_result() );
	433	Type * result = arg->get_result();
	434	if ( skipCopyConstruct( result ) ) return; // skip certain non-copyable types
	435
	436	// type may involve type variables, so apply type substitution to get temporary variable's actual type
	437	result = result->clone();
[31f379c]	438	env->apply( result );
[68fe077a]	439	ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), Type::StorageClasses(), LinkageSpec::C, 0, result, 0 );
[615a096]	440	tmp->get_type()->set_const( false );
[1132b62]	441
	442	// create and resolve copy constructor
	443	CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; )
[65660bd]	444	Expression * cpCtor = makeCtorDtor( "?{}", tmp, arg );
	445
	446	if ( ApplicationExpr * appExpr = dynamic_cast< ApplicationExpr * >( cpCtor ) ) {
	447	// if the chosen constructor is intrinsic, the copy is unnecessary, so
	448	// don't create the temporary and don't call the copy constructor
	449	VariableExpr * function = dynamic_cast< VariableExpr * >( appExpr->get_function() );
	450	assert( function );
	451	if ( function->get_var()->get_linkage() == LinkageSpec::Intrinsic ) return;
	452	}
	453
	454	// replace argument to function call with temporary
	455	arg = new CommaExpr( cpCtor, new VariableExpr( tmp ) );
	456	impCpCtorExpr->get_tempDecls().push_back( tmp );
	457	impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", tmp ) );
[1132b62]	458	}
[c2931ea]	459
[092528b]	460	void ResolveCopyCtors::destructRet( ObjectDecl * ret, ImplicitCopyCtorExpr * impCpCtorExpr ) {
	461	impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
[1132b62]	462	}
	463
	464	void ResolveCopyCtors::visit( ImplicitCopyCtorExpr *impCpCtorExpr ) {
[c2931ea]	465	CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; )
[141b786]	466	Parent::visit( impCpCtorExpr );
[31f379c]	467	env = envMap.at(impCpCtorExpr);
	468	assert( env );
[c2931ea]	469
	470	ApplicationExpr * appExpr = impCpCtorExpr->get_callExpr();
	471
	472	// take each argument and attempt to copy construct it.
	473	for ( Expression * & arg : appExpr->get_args() ) {
[1132b62]	474	copyConstructArg( arg, impCpCtorExpr );
[adcc065]	475	} // for
[db4ecc5]	476
[adcc065]	477	// each return value from the call needs to be connected with an ObjectDecl at the call site, which is
	478	// initialized with the return value and is destructed later
[31f379c]	479	// xxx - handle named return values?
[906e24d]	480	Type * result = appExpr->get_result();
	481	if ( ! result->isVoid() ) {
[1132b62]	482	static UniqueName retNamer("_tmp_cp_ret");
[c2931ea]	483	result = result->clone();
[31f379c]	484	env->apply( result );
[68fe077a]	485	ObjectDecl * ret = new ObjectDecl( retNamer.newName(), Type::StorageClasses(), LinkageSpec::C, 0, result, 0 );
[615a096]	486	ret->get_type()->set_const( false );
[c2931ea]	487	impCpCtorExpr->get_returnDecls().push_back( ret );
	488	CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; )
[615a096]	489	if ( ! result->get_lvalue() ) {
[dc86541]	490	// destructing lvalue returns is bad because it can cause multiple destructor calls to the same object - the returned object is not a temporary
[092528b]	491	destructRet( ret, impCpCtorExpr );
[dc86541]	492	}
[adcc065]	493	} // for
[c2931ea]	494	CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; )
[db4ecc5]	495	}
	496
[31f379c]	497	void ResolveCopyCtors::visit( StmtExpr * stmtExpr ) {
	498	Parent::visit( stmtExpr );
	499	env = envMap.at(stmtExpr);
	500	assert( stmtExpr->get_result() );
	501	Type * result = stmtExpr->get_result();
	502	if ( ! result->isVoid() ) {
	503	static UniqueName retNamer("_tmp_stmtexpr_ret");
	504
	505	// create variable that will hold the result of the stmt expr
	506	result = result->clone();
	507	env->apply( result );
[68fe077a]	508	ObjectDecl * ret = new ObjectDecl( retNamer.newName(), Type::StorageClasses(), LinkageSpec::C, 0, result, 0 );
[615a096]	509	ret->get_type()->set_const( false );
[31f379c]	510	stmtExpr->get_returnDecls().push_front( ret );
	511
	512	// must have a non-empty body, otherwise it wouldn't have a result
	513	CompoundStmt * body = stmtExpr->get_statements();
	514	assert( ! body->get_kids().empty() );
	515	// must be an ExprStmt, otherwise it wouldn't have a result
	516	ExprStmt * last = safe_dynamic_cast< ExprStmt * >( body->get_kids().back() );
	517	last->set_expr( makeCtorDtor( "?{}", ret, last->get_expr() ) );
	518
[092528b]	519	stmtExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) );
[31f379c]	520	} // if
	521
	522	}
	523
[141b786]	524	void ResolveCopyCtors::visit( UniqueExpr * unqExpr ) {
	525	static std::unordered_set< int > vars;
[597db97f]	526	unqCount[ unqExpr->get_id() ]++; // count the number of unique expressions for each ID
[141b786]	527	if ( vars.count( unqExpr->get_id() ) ) {
	528	// xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated
	529	return;
	530	}
	531
	532	Parent::visit( unqExpr );
	533	// it should never be necessary to wrap a void-returning expression in a UniqueExpr - if this assumption changes, this needs to be rethought
	534	assert( unqExpr->get_result() );
	535	if ( ImplicitCopyCtorExpr * impCpCtorExpr = dynamic_cast<ImplicitCopyCtorExpr*>( unqExpr->get_expr() ) ) {
	536	// note the variable used as the result from the call
	537	assert( impCpCtorExpr->get_result() && impCpCtorExpr->get_returnDecls().size() == 1 );
	538	unqExpr->set_var( new VariableExpr( impCpCtorExpr->get_returnDecls().front() ) );
	539	} else {
	540	// expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression
[14a33790]	541	unqExpr->set_object( new ObjectDecl( toString("_unq", unqExpr->get_id()), Type::StorageClasses(), LinkageSpec::C, nullptr, unqExpr->get_result()->clone(), nullptr ) );
[141b786]	542	unqExpr->set_var( new VariableExpr( unqExpr->get_object() ) );
	543	}
	544	vars.insert( unqExpr->get_id() );
	545	}
	546
[c2931ea]	547	Expression * FixCopyCtors::mutate( ImplicitCopyCtorExpr * impCpCtorExpr ) {
	548	CP_CTOR_PRINT( std::cerr << "FixCopyCtors: " << impCpCtorExpr << std::endl; )
	549
[31f379c]	550	impCpCtorExpr = safe_dynamic_cast< ImplicitCopyCtorExpr * >( Parent::mutate( impCpCtorExpr ) );
[c2931ea]	551	std::list< ObjectDecl * > & tempDecls = impCpCtorExpr->get_tempDecls();
	552	std::list< ObjectDecl * > & returnDecls = impCpCtorExpr->get_returnDecls();
	553	std::list< Expression * > & dtors = impCpCtorExpr->get_dtors();
[845cedc]	554
[c2931ea]	555	// add all temporary declarations and their constructors
	556	for ( ObjectDecl * obj : tempDecls ) {
	557	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
[adcc065]	558	} // for
[c2931ea]	559	for ( ObjectDecl * obj : returnDecls ) {
	560	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
[adcc065]	561	} // for
[db4ecc5]	562
[c2931ea]	563	// add destructors after current statement
	564	for ( Expression * dtor : dtors ) {
	565	stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
[adcc065]	566	} // for
[db4ecc5]	567
[c2931ea]	568	// xxx - update to work with multiple return values
	569	ObjectDecl * returnDecl = returnDecls.empty() ? NULL : returnDecls.front();
	570	Expression * callExpr = impCpCtorExpr->get_callExpr();
	571
	572	CP_CTOR_PRINT( std::cerr << "Coming out the back..." << impCpCtorExpr << std::endl; )
	573
	574	// detach fields from wrapper node so that it can be deleted without deleting too much
	575	dtors.clear();
	576	tempDecls.clear();
	577	returnDecls.clear();
	578	impCpCtorExpr->set_callExpr( NULL );
	579	impCpCtorExpr->set_env( NULL );
	580	delete impCpCtorExpr;
	581
	582	if ( returnDecl ) {
	583	UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
	584	assign->get_args().push_back( new VariableExpr( returnDecl ) );
	585	assign->get_args().push_back( callExpr );
	586	// know the result type of the assignment is the type of the LHS (minus the pointer), so
	587	// add that onto the assignment expression so that later steps have the necessary information
[906e24d]	588	assign->set_result( returnDecl->get_type()->clone() );
[c2931ea]	589
	590	Expression * retExpr = new CommaExpr( assign, new VariableExpr( returnDecl ) );
[615a096]	591	if ( callExpr->get_result()->get_lvalue() ) {
[adcc065]	592	// lvalue returning functions are funny. Lvalue.cc inserts a *? in front of any lvalue returning
	593	// non-intrinsic function. Add an AddressExpr to the call to negate the derefence and change the
	594	// type of the return temporary from T to T* to properly capture the return value. Then dereference
	595	// the result of the comma expression, since the lvalue returning call was originally wrapped with
	596	// an AddressExpr. Effectively, this turns
[c2931ea]	597	// lvalue T f();
[b3b2077]	598	// &*f();
[c2931ea]	599	// into
[b3b2077]	600	// T * f();
[c2931ea]	601	// T * tmp_cp_retN;
[b3b2077]	602	// &(tmp_cp_retN = &f(), tmp_cp_retN); // the first * and second & are generated here
[c2931ea]	603	// which work out in terms of types, but is pretty messy. It would be nice to find a better way.
	604	assign->get_args().back() = new AddressExpr( assign->get_args().back() );
	605
	606	returnDecl->set_type( new PointerType( Type::Qualifiers(), returnDecl->get_type() ) );
[b3b2077]	607	retExpr->set_result( new PointerType( Type::Qualifiers(), retExpr->get_result() ) );
	608	retExpr = UntypedExpr::createDeref( retExpr );
[adcc065]	609	} // if
[31f379c]	610	// move env from callExpr to retExpr
	611	retExpr->set_env( callExpr->get_env() );
	612	callExpr->set_env( nullptr );
[c2931ea]	613	return retExpr;
	614	} else {
	615	return callExpr;
[adcc065]	616	} // if
[4ffdd63]	617	}
[c2931ea]	618
[31f379c]	619	Expression * FixCopyCtors::mutate( StmtExpr * stmtExpr ) {
[65aca88]	620	// function call temporaries should be placed at statement-level, rather than nested inside of a new statement expression,
	621	// since temporaries can be shared across sub-expressions, e.g.
	622	// [A, A] f();
	623	// g([A] x, [A] y);
	624	// f(g());
	625	// f is executed once, so the return temporary is shared across the tuple constructors for x and y.
	626	std::list< Statement * > & stmts = stmtExpr->get_statements()->get_kids();
	627	for ( Statement *& stmt : stmts ) {
	628	stmt = stmt->acceptMutator( *this );
	629	} // for
	630	// stmtExpr = safe_dynamic_cast< StmtExpr * >( Parent::mutate( stmtExpr ) );
[31f379c]	631	assert( stmtExpr->get_result() );
	632	Type * result = stmtExpr->get_result();
	633	if ( ! result->isVoid() ) {
	634	for ( ObjectDecl * obj : stmtExpr->get_returnDecls() ) {
	635	stmtsToAdd.push_back( new DeclStmt( noLabels, obj ) );
	636	} // for
	637	// add destructors after current statement
	638	for ( Expression * dtor : stmtExpr->get_dtors() ) {
	639	stmtsToAddAfter.push_back( new ExprStmt( noLabels, dtor ) );
	640	} // for
	641	// must have a non-empty body, otherwise it wouldn't have a result
	642	CompoundStmt * body = stmtExpr->get_statements();
	643	assert( ! body->get_kids().empty() );
	644	assert( ! stmtExpr->get_returnDecls().empty() );
	645	body->get_kids().push_back( new ExprStmt( noLabels, new VariableExpr( stmtExpr->get_returnDecls().front() ) ) );
[a28bc02]	646	stmtExpr->get_returnDecls().clear();
	647	stmtExpr->get_dtors().clear();
[31f379c]	648	}
[a28bc02]	649	assert( stmtExpr->get_returnDecls().empty() );
	650	assert( stmtExpr->get_dtors().empty() );
[31f379c]	651	return stmtExpr;
	652	}
	653
[141b786]	654	Expression * FixCopyCtors::mutate( UniqueExpr * unqExpr ) {
[597db97f]	655	unqCount[ unqExpr->get_id() ]--;
	656	static std::unordered_map< int, std::list< Statement * > > dtors;
[141b786]	657	static std::unordered_map< int, UniqueExpr * > unqMap;
	658	static std::unordered_set< int > addDeref;
	659	// has to be done to clean up ImplicitCopyCtorExpr nodes, even when this node was skipped in previous passes
	660	if ( unqMap.count( unqExpr->get_id() ) ) {
	661	// take data from other UniqueExpr to ensure consistency
	662	delete unqExpr->get_expr();
	663	unqExpr->set_expr( unqMap[unqExpr->get_id()]->get_expr()->clone() );
	664	delete unqExpr->get_result();
	665	unqExpr->set_result( maybeClone( unqExpr->get_expr()->get_result() ) );
[597db97f]	666	if ( unqCount[ unqExpr->get_id() ] == 0 ) { // insert destructor after the last use of the unique expression
[edbdbe6]	667	stmtsToAddAfter.splice( stmtsToAddAfter.end(), dtors[ unqExpr->get_id() ] );
[597db97f]	668	}
[141b786]	669	if ( addDeref.count( unqExpr->get_id() ) ) {
	670	// other UniqueExpr was dereferenced because it was an lvalue return, so this one should be too
	671	return UntypedExpr::createDeref( unqExpr );
	672	}
	673	return unqExpr;
	674	}
[597db97f]	675	FixCopyCtors fixer( unqCount );
	676	unqExpr->set_expr( unqExpr->get_expr()->acceptMutator( fixer ) ); // stmtexprs contained should not be separately fixed, so this must occur after the lookup
	677	stmtsToAdd.splice( stmtsToAdd.end(), fixer.stmtsToAdd );
[141b786]	678	unqMap[unqExpr->get_id()] = unqExpr;
[edbdbe6]	679	if ( unqCount[ unqExpr->get_id() ] == 0 ) { // insert destructor after the last use of the unique expression
	680	stmtsToAddAfter.splice( stmtsToAddAfter.end(), dtors[ unqExpr->get_id() ] );
	681	} else { // remember dtors for last instance of unique expr
	682	dtors[ unqExpr->get_id() ] = fixer.stmtsToAddAfter;
	683	}
[141b786]	684	if ( UntypedExpr * deref = dynamic_cast< UntypedExpr * >( unqExpr->get_expr() ) ) {
	685	// unique expression is now a dereference, because the inner expression is an lvalue returning function call.
	686	// Normalize the expression by dereferencing the unique expression, rather than the inner expression
	687	// (i.e. move the dereference out a level)
	688	assert( getFunctionName( deref ) == "*?" );
	689	unqExpr->set_expr( getCallArg( deref, 0 ) );
	690	getCallArg( deref, 0 ) = unqExpr;
	691	addDeref.insert( unqExpr->get_id() );
	692	return deref;
	693	}
	694	return unqExpr;
	695	}
	696
[aff3af4]	697	DeclarationWithType FixInit::postmutate( ObjectDecl objDecl ) {
	698	// since this removes the init field from objDecl, it must occur after children are mutated (i.e. postmutate)
[c2931ea]	699	if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
	700	// a decision should have been made by the resolver, so ctor and init are not both non-NULL
	701	assert( ! ctorInit->get_ctor() \|\| ! ctorInit->get_init() );
	702	if ( Statement * ctor = ctorInit->get_ctor() ) {
[08d5507b]	703	if ( objDecl->get_storageClasses().is_static ) {
[72e9222]	704	// originally wanted to take advantage of gcc nested functions, but
[f9cebb5]	705	// we get memory errors with this approach. To remedy this, the static
	706	// variable is hoisted when the destructor needs to be called.
[72e9222]	707	//
[c2931ea]	708	// generate:
[f9cebb5]	709	// static T __objName_static_varN;
[72e9222]	710	// void __objName_dtor_atexitN() {
[f9cebb5]	711	// __dtor__...;
[72e9222]	712	// }
	713	// int f(...) {
	714	// ...
	715	// static bool __objName_uninitialized = true;
	716	// if (__objName_uninitialized) {
	717	// __ctor(__objName);
	718	// __objName_uninitialized = false;
[f9cebb5]	719	// atexit(__objName_dtor_atexitN);
[c2931ea]	720	// }
[72e9222]	721	// ...
[c2931ea]	722	// }
	723
[72e9222]	724	static UniqueName dtorCallerNamer( "_dtor_atexit" );
	725
	726	// static bool __objName_uninitialized = true
[c2931ea]	727	BasicType * boolType = new BasicType( Type::Qualifiers(), BasicType::Bool );
	728	SingleInit * boolInitExpr = new SingleInit( new ConstantExpr( Constant( boolType->clone(), "1" ) ), noDesignators );
[68fe077a]	729	ObjectDecl * isUninitializedVar = new ObjectDecl( objDecl->get_mangleName() + "_uninitialized", Type::StorageClasses( Type::Static ), LinkageSpec::Cforall, 0, boolType, boolInitExpr );
[c2931ea]	730	isUninitializedVar->fixUniqueId();
	731
	732	// __objName_uninitialized = false;
	733	UntypedExpr * setTrue = new UntypedExpr( new NameExpr( "?=?" ) );
	734	setTrue->get_args().push_back( new VariableExpr( isUninitializedVar ) );
	735	setTrue->get_args().push_back( new ConstantExpr( Constant( boolType->clone(), "0" ) ) );
	736
	737	// generate body of if
	738	CompoundStmt * initStmts = new CompoundStmt( noLabels );
	739	std::list< Statement * > & body = initStmts->get_kids();
	740	body.push_back( ctor );
	741	body.push_back( new ExprStmt( noLabels, setTrue ) );
	742
	743	// put it all together
	744	IfStmt * ifStmt = new IfStmt( noLabels, new VariableExpr( isUninitializedVar ), initStmts, 0 );
	745	stmtsToAddAfter.push_back( new DeclStmt( noLabels, isUninitializedVar ) );
	746	stmtsToAddAfter.push_back( ifStmt );
[72e9222]	747
[a4dd728]	748	Statement * dtor = ctorInit->get_dtor();
	749	objDecl->set_init( NULL );
	750	ctorInit->set_ctor( NULL );
	751	ctorInit->set_dtor( nullptr );
	752	if ( dtor ) {
[f9cebb5]	753	// if the object has a non-trivial destructor, have to
	754	// hoist it and the object into the global space and
	755	// call the destructor function with atexit.
	756
[a4dd728]	757	Statement * dtorStmt = dtor->clone();
[f9cebb5]	758
	759	// void __objName_dtor_atexitN(...) {...}
[68fe077a]	760	FunctionDecl * dtorCaller = new FunctionDecl( objDecl->get_mangleName() + dtorCallerNamer.newName(), Type::StorageClasses( Type::Static ), LinkageSpec::C, new FunctionType( Type::Qualifiers(), false ), new CompoundStmt( noLabels ) );
[f9cebb5]	761	dtorCaller->fixUniqueId();
[c8dfcd3]	762	dtorCaller->get_statements()->push_back( dtorStmt );
[f9cebb5]	763
	764	// atexit(dtor_atexit);
	765	UntypedExpr * callAtexit = new UntypedExpr( new NameExpr( "atexit" ) );
	766	callAtexit->get_args().push_back( new VariableExpr( dtorCaller ) );
	767
	768	body.push_back( new ExprStmt( noLabels, callAtexit ) );
	769
	770	// hoist variable and dtor caller decls to list of decls that will be added into global scope
	771	staticDtorDecls.push_back( objDecl );
	772	staticDtorDecls.push_back( dtorCaller );
	773
	774	// need to rename object uniquely since it now appears
	775	// at global scope and there could be multiple function-scoped
	776	// static variables with the same name in different functions.
[c8dfcd3]	777	// Note: it isn't sufficient to modify only the mangleName, because
	778	// then subsequent Indexer passes can choke on seeing the object's name
	779	// if another object has the same name and type. An unfortunate side-effect
	780	// of renaming the object is that subsequent NameExprs may fail to resolve,
	781	// but there shouldn't be any remaining past this point.
[f9cebb5]	782	static UniqueName staticNamer( "_static_var" );
[c8dfcd3]	783	objDecl->set_name( objDecl->get_name() + staticNamer.newName() );
	784	objDecl->set_mangleName( SymTab::Mangler::mangle( objDecl ) );
[f9cebb5]	785
	786	// xxx - temporary hack: need to return a declaration, but want to hoist the current object out of this scope
	787	// create a new object which is never used
	788	static UniqueName dummyNamer( "_dummy" );
[68fe077a]	789	ObjectDecl * dummy = new ObjectDecl( dummyNamer.newName(), Type::StorageClasses( Type::Static ), LinkageSpec::Cforall, 0, new PointerType( Type::Qualifiers(), new VoidType( Type::Qualifiers() ) ), 0, std::list< Attribute * >{ new Attribute("unused") } );
[a4dd728]	790	delete ctorInit;
[f9cebb5]	791	return dummy;
	792	}
[c2931ea]	793	} else {
[233e4d9]	794	ImplicitCtorDtorStmt * implicit = safe_dynamic_cast< ImplicitCtorDtorStmt * > ( ctor );
	795	ExprStmt * ctorStmt = dynamic_cast< ExprStmt * >( implicit->get_callStmt() );
	796	ApplicationExpr * ctorCall = nullptr;
	797	if ( ctorStmt && (ctorCall = isIntrinsicCallExpr( ctorStmt->get_expr() )) && ctorCall->get_args().size() == 2 ) {
	798	// clean up intrinsic copy constructor calls by making them into SingleInits
	799	objDecl->set_init( new SingleInit( ctorCall->get_args().back() ) );
	800	ctorCall->get_args().pop_back();
	801	} else {
	802	stmtsToAddAfter.push_back( ctor );
	803	objDecl->set_init( NULL );
	804	ctorInit->set_ctor( NULL );
	805	}
[adcc065]	806	} // if
[c2931ea]	807	} else if ( Initializer * init = ctorInit->get_init() ) {
	808	objDecl->set_init( init );
	809	ctorInit->set_init( NULL );
	810	} else {
	811	// no constructor and no initializer, which is okay
	812	objDecl->set_init( NULL );
[adcc065]	813	} // if
[c2931ea]	814	delete ctorInit;
[adcc065]	815	} // if
[c2931ea]	816	return objDecl;
[db4ecc5]	817	}
	818
[52c14b3]	819	void ObjDeclCollector::visit( CompoundStmt * compoundStmt ) {
[c2931ea]	820	std::set< ObjectDecl * > prevVars = curVars;
	821	Parent::visit( compoundStmt );
	822	curVars = prevVars;
[db4ecc5]	823	}
	824
[52c14b3]	825	void ObjDeclCollector::visit( DeclStmt * stmt ) {
[4b2589a]	826	// keep track of all variables currently in scope
[c2931ea]	827	if ( ObjectDecl * objDecl = dynamic_cast< ObjectDecl * > ( stmt->get_decl() ) ) {
	828	curVars.insert( objDecl );
[adcc065]	829	} // if
[e39aa0f]	830	Parent::visit( stmt );
[db4ecc5]	831	}
	832
[c2931ea]	833	void LabelFinder::handleStmt( Statement * stmt ) {
[4b2589a]	834	// for each label, remember the variables in scope at that label.
[c2931ea]	835	for ( Label l : stmt->get_labels() ) {
	836	vars[l] = curVars;
[adcc065]	837	} // for
[71f4e4f]	838	}
[f1e012b]	839
[ec79847]	840	template<typename Iterator, typename OutputIterator>
	841	void insertDtors( Iterator begin, Iterator end, OutputIterator out ) {
	842	for ( Iterator it = begin ; it != end ; ++it ) {
[adcc065]	843	// extract destructor statement from the object decl and insert it into the output. Note that this is
	844	// only called on lists of non-static objects with implicit non-intrinsic dtors, so if the user manually
	845	// calls an intrinsic dtor then the call must (and will) still be generated since the argument may
	846	// contain side effects.
[c2931ea]	847	ObjectDecl * objDecl = *it;
	848	ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() );
	849	assert( ctorInit && ctorInit->get_dtor() );
	850	*out++ = ctorInit->get_dtor()->clone();
[adcc065]	851	} // for
[f1e012b]	852	}
[39786813]	853
[c2931ea]	854	void InsertDtors::visit( ObjectDecl * objDecl ) {
	855	// remember non-static destructed objects so that their destructors can be inserted later
[08d5507b]	856	if ( ! objDecl->get_storageClasses().is_static ) {
[c2931ea]	857	if ( ConstructorInit * ctorInit = dynamic_cast< ConstructorInit * >( objDecl->get_init() ) ) {
	858	// a decision should have been made by the resolver, so ctor and init are not both non-NULL
	859	assert( ! ctorInit->get_ctor() \|\| ! ctorInit->get_init() );
	860	Statement * dtor = ctorInit->get_dtor();
[f9cebb5]	861	if ( dtor && ! isIntrinsicSingleArgCallStmt( dtor ) ) {
[c2931ea]	862	// don't need to call intrinsic dtor, because it does nothing, but
	863	// non-intrinsic dtors must be called
	864	reverseDeclOrder.front().push_front( objDecl );
[adcc065]	865	} // if
	866	} // if
	867	} // if
[c2931ea]	868	Parent::visit( objDecl );
	869	}
[39786813]	870
[52c14b3]	871	template< typename Visitor >
	872	void handleFuncDecl( FunctionDecl * funcDecl, Visitor & visitor ) {
	873	maybeAccept( funcDecl->get_functionType(), visitor );
	874	maybeAccept( funcDecl->get_statements(), visitor );
	875	}
	876
	877	void InsertDtors::visit( FunctionDecl * funcDecl ) {
	878	// each function needs to have its own set of labels
	879	ValueGuard< LabelFinder::LabelMap > oldLabels( labelVars );
	880	labelVars.clear();
	881	handleFuncDecl( funcDecl, finder );
	882
	883	// all labels for this function have been collected, insert destructors as appropriate.
	884	// can't be Parent::mutate, because ObjDeclCollector bottoms out on FunctionDecl
	885	handleFuncDecl( funcDecl, *this );
	886	}
	887
[c2931ea]	888	void InsertDtors::visit( CompoundStmt * compoundStmt ) {
[adcc065]	889	// visit statements - this will also populate reverseDeclOrder list. don't want to dump all destructors
	890	// when block is left, just the destructors associated with variables defined in this block, so push a new
	891	// list to the top of the stack so that we can differentiate scopes
[c2931ea]	892	reverseDeclOrder.push_front( OrderedDecls() );
	893	Parent::visit( compoundStmt );
[39786813]	894
[0661678]	895	// add destructors for the current scope that we're exiting, unless the last statement is a return, which
	896	// causes unreachable code warnings
[c2931ea]	897	std::list< Statement * > & statements = compoundStmt->get_kids();
[0661678]	898	if ( ! statements.empty() && ! dynamic_cast< ReturnStmt * >( statements.back() ) ) {
	899	insertDtors( reverseDeclOrder.front().begin(), reverseDeclOrder.front().end(), back_inserter( statements ) );
	900	}
[c2931ea]	901	reverseDeclOrder.pop_front();
[39786813]	902	}
	903
[d7dc824]	904	void InsertDtors::visit( __attribute((unused)) ReturnStmt * returnStmt ) {
[4b2589a]	905	// return exits all scopes, so dump destructors for all scopes
[c2931ea]	906	for ( OrderedDecls & od : reverseDeclOrder ) {
	907	insertDtors( od.begin(), od.end(), back_inserter( stmtsToAdd ) );
[adcc065]	908	} // for
[39786813]	909	}
[f1e012b]	910
[adcc065]	911	// Handle break/continue/goto in the same manner as C++. Basic idea: any objects that are in scope at the
	912	// BranchStmt but not at the labelled (target) statement must be destructed. If there are any objects in scope
	913	// at the target location but not at the BranchStmt then those objects would be uninitialized so notify the user
	914	// of the error. See C++ Reference 6.6 Jump Statements for details.
[c2931ea]	915	void InsertDtors::handleGoto( BranchStmt * stmt ) {
[e39aa0f]	916	assert( stmt->get_target() != "" && "BranchStmt missing a label" );
[c2931ea]	917	// S_L = lvars = set of objects in scope at label definition
	918	// S_G = curVars = set of objects in scope at goto statement
	919	ObjectSet & lvars = labelVars[ stmt->get_target() ];
	920
	921	DTOR_PRINT(
	922	std::cerr << "at goto label: " << stmt->get_target().get_name() << std::endl;
	923	std::cerr << "S_G = " << printSet( curVars ) << std::endl;
	924	std::cerr << "S_L = " << printSet( lvars ) << std::endl;
	925	)
	926
	927	ObjectSet diff;
	928	// S_L-S_G results in set of objects whose construction is skipped - it's an error if this set is non-empty
	929	std::set_difference( lvars.begin(), lvars.end(), curVars.begin(), curVars.end(), std::inserter( diff, diff.begin() ) );
	930	DTOR_PRINT(
	931	std::cerr << "S_L-S_G = " << printSet( diff ) << std::endl;
	932	)
	933	if ( ! diff.empty() ) {
	934	throw SemanticError( std::string("jump to label '") + stmt->get_target().get_name() + "' crosses initialization of " + (*diff.begin())->get_name() + " ", stmt );
[adcc065]	935	} // if
[c2931ea]	936	// S_G-S_L results in set of objects that must be destructed
	937	diff.clear();
	938	std::set_difference( curVars.begin(), curVars.end(), lvars.begin(), lvars.end(), std::inserter( diff, diff.end() ) );
	939	DTOR_PRINT(
	940	std::cerr << "S_G-S_L = " << printSet( diff ) << std::endl;
	941	)
	942	if ( ! diff.empty() ) {
	943	// go through decl ordered list of objectdecl. for each element that occurs in diff, output destructor
	944	OrderedDecls ordered;
	945	for ( OrderedDecls & rdo : reverseDeclOrder ) {
	946	// add elements from reverseDeclOrder into ordered if they occur in diff - it is key that this happens in reverse declaration order.
	947	copy_if( rdo.begin(), rdo.end(), back_inserter( ordered ), [&]( ObjectDecl * objDecl ) { return diff.count( objDecl ); } );
[adcc065]	948	} // for
[c2931ea]	949	insertDtors( ordered.begin(), ordered.end(), back_inserter( stmtsToAdd ) );
[adcc065]	950	} // if
[c2931ea]	951	}
[39786813]	952
[c2931ea]	953	void InsertDtors::visit( BranchStmt * stmt ) {
	954	switch( stmt->get_type() ) {
[adcc065]	955	case BranchStmt::Continue:
	956	case BranchStmt::Break:
	957	// could optimize the break/continue case, because the S_L-S_G check is unnecessary (this set should
	958	// always be empty), but it serves as a small sanity check.
	959	case BranchStmt::Goto:
	960	handleGoto( stmt );
	961	break;
	962	default:
	963	assert( false );
	964	} // switch
[c2931ea]	965	}
[79970ed]	966
	967	bool checkWarnings( FunctionDecl * funcDecl ) {
	968	// only check for warnings if the current function is a user-defined
	969	// constructor or destructor
	970	if ( ! funcDecl ) return false;
	971	if ( ! funcDecl->get_statements() ) return false;
	972	return isCtorDtor( funcDecl->get_name() ) && ! LinkageSpec::isOverridable( funcDecl->get_linkage() );
	973	}
	974
[c8dfcd3]	975	void GenStructMemberCalls::visit( FunctionDecl * funcDecl ) {
	976	ValueGuard< FunctionDecl * > oldFunction( funcDecl );
	977	ValueGuard< std::set< DeclarationWithType * > > oldUnhandled( unhandled );
[64ac636]	978	ValueGuard< std::map< DeclarationWithType *, CodeLocation > > oldUsedUninit( usedUninit );
[c8dfcd3]	979	ValueGuard< ObjectDecl * > oldThisParam( thisParam );
	980	ValueGuard< bool > oldIsCtor( isCtor );
[44f6341]	981	ValueGuard< StructDecl * > oldStructDecl( structDecl );
[64ac636]	982	errors = SemanticError(); // clear previous errors
[c8dfcd3]	983
	984	// need to start with fresh sets
	985	unhandled.clear();
	986	usedUninit.clear();
[79970ed]	987
	988	function = funcDecl;
[c8dfcd3]	989	isCtor = isConstructor( function->get_name() );
	990	if ( checkWarnings( function ) ) {
	991	FunctionType * type = function->get_functionType();
[79970ed]	992	assert( ! type->get_parameters().empty() );
	993	thisParam = safe_dynamic_cast< ObjectDecl * >( type->get_parameters().front() );
	994	PointerType * ptrType = safe_dynamic_cast< PointerType * > ( thisParam->get_type() );
	995	StructInstType * structType = dynamic_cast< StructInstType * >( ptrType->get_base() );
	996	if ( structType ) {
[44f6341]	997	structDecl = structType->get_baseStruct();
[79970ed]	998	for ( Declaration * member : structDecl->get_members() ) {
	999	if ( ObjectDecl * field = dynamic_cast< ObjectDecl * >( member ) ) {
	1000	// record all of the struct type's members that need to be constructed or
	1001	// destructed by the end of the function
	1002	unhandled.insert( field );
	1003	}
	1004	}
	1005	}
	1006	}
[c8dfcd3]	1007	Parent::visit( function );
	1008
	1009	// remove the unhandled objects from usedUninit, because a call is inserted
	1010	// to handle them - only objects that are later constructed are used uninitialized.
[64ac636]	1011	std::map< DeclarationWithType *, CodeLocation > diff;
	1012	// need the comparator since usedUninit and unhandled have different types
	1013	struct comp_t {
	1014	typedef decltype(usedUninit)::value_type usedUninit_t;
	1015	typedef decltype(unhandled)::value_type unhandled_t;
	1016	bool operator()(usedUninit_t x, unhandled_t y) { return x.first < y; }
	1017	bool operator()(unhandled_t x, usedUninit_t y) { return x < y.first; }
	1018	} comp;
	1019	std::set_difference( usedUninit.begin(), usedUninit.end(), unhandled.begin(), unhandled.end(), std::inserter( diff, diff.begin() ), comp );
	1020	for ( auto p : diff ) {
	1021	DeclarationWithType * member = p.first;
	1022	CodeLocation loc = p.second;
	1023	// xxx - make error message better by also tracking the location that the object is constructed at?
	1024	emit( loc, "in ", CodeGen::genPrettyType( function->get_functionType(), function->get_name() ), ", field ", member->get_name(), " used before being constructed" );
[79970ed]	1025	}
	1026
[c8dfcd3]	1027	if ( ! unhandled.empty() ) {
	1028	// need to explicitly re-add function parameters in order to resolve copy constructors
	1029	enterScope();
[b16898e]	1030	maybeAccept( function->get_functionType(), *this );
[44f6341]	1031
	1032	// need to iterate through members in reverse in order for
	1033	// ctor/dtor statements to come out in the right order
[1ba88a0]	1034	for ( Declaration * member : reverseIterate( structDecl->get_members() ) ) {
[44f6341]	1035	DeclarationWithType * field = dynamic_cast< DeclarationWithType * >( member );
	1036	// skip non-DWT members
	1037	if ( ! field ) continue;
	1038	// skip handled members
	1039	if ( ! unhandled.count( field ) ) continue;
	1040
	1041	// insert and resolve default/copy constructor call for each field that's unhandled
[c8dfcd3]	1042	std::list< Statement * > stmt;
[d9fa60a]	1043	UntypedExpr * deref = UntypedExpr::createDeref( new VariableExpr( thisParam ) );
[4d4882a]	1044
	1045	Expression * arg2 = 0;
	1046	if ( isCopyConstructor( function ) ) {
[44f6341]	1047	// if copy ctor, need to pass second-param-of-this-function.field
[4d4882a]	1048	std::list< DeclarationWithType * > & params = function->get_functionType()->get_parameters();
	1049	assert( params.size() == 2 );
[44f6341]	1050	arg2 = new MemberExpr( field, new VariableExpr( params.back() ) );
[4d4882a]	1051	}
	1052	InitExpander srcParam( arg2 );
[44f6341]	1053	SymTab::genImplicitCall( srcParam, new MemberExpr( field, deref ), function->get_name(), back_inserter( stmt ), field, isCtor );
[c8dfcd3]	1054
	1055	assert( stmt.size() <= 1 );
	1056	if ( stmt.size() == 1 ) {
	1057	Statement * callStmt = stmt.front();
	1058
	1059	MutatingResolver resolver( *this );
	1060	try {
	1061	callStmt->acceptMutator( resolver );
	1062	if ( isCtor ) {
	1063	function->get_statements()->push_front( callStmt );
	1064	} else {
	1065	// destructor statements should be added at the end
	1066	function->get_statements()->push_back( callStmt );
	1067	}
	1068	} catch ( SemanticError & error ) {
[64ac636]	1069	emit( funcDecl->location, "in ", CodeGen::genPrettyType( function->get_functionType(), function->get_name() ), ", field ", field->get_name(), " not explicitly ", isCtor ? "constructed" : "destructed", " and no ", isCtor ? "default constructor" : "destructor", " found" );
[c8dfcd3]	1070	}
	1071	}
	1072	}
	1073	leaveScope();
	1074	}
[64ac636]	1075	if (! errors.isEmpty()) {
	1076	throw errors;
	1077	}
[79970ed]	1078	}
	1079
[c8dfcd3]	1080	void GenStructMemberCalls::visit( ApplicationExpr * appExpr ) {
[79970ed]	1081	if ( ! checkWarnings( function ) ) return;
	1082
	1083	std::string fname = getFunctionName( appExpr );
	1084	if ( fname == function->get_name() ) {
	1085	// call to same kind of function
	1086	Expression * firstParam = appExpr->get_args().front();
	1087
	1088	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( firstParam ) ) {
	1089	// if calling another constructor on thisParam, assume that function handles
	1090	// all members - if it doesn't a warning will appear in that function.
	1091	if ( varExpr->get_var() == thisParam ) {
	1092	unhandled.clear();
	1093	}
	1094	} else {
	1095	// if first parameter is a member expression then
	1096	// remove the member from unhandled set.
	1097	handleFirstParam( firstParam );
	1098	}
	1099	}
	1100
	1101	Parent::visit( appExpr );
	1102	}
	1103
[c8dfcd3]	1104	void GenStructMemberCalls::handleFirstParam( Expression * firstParam ) {
[79970ed]	1105	using namespace std;
	1106	if ( AddressExpr * addrExpr = dynamic_cast< AddressExpr * >( firstParam ) ) {
	1107	if ( MemberExpr * memberExpr = dynamic_cast< MemberExpr * >( addrExpr->get_arg() ) ) {
	1108	if ( ApplicationExpr * deref = dynamic_cast< ApplicationExpr * >( memberExpr->get_aggregate() ) ) {
	1109	if ( getFunctionName( deref ) == "*?" && deref->get_args().size() == 1 ) {
	1110	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( deref->get_args().front() ) ) {
	1111	if ( varExpr->get_var() == thisParam ) {
	1112	unhandled.erase( memberExpr->get_member() );
	1113	}
	1114	}
	1115	}
	1116	}
	1117	}
	1118	}
	1119	}
	1120
[c8dfcd3]	1121	void GenStructMemberCalls::visit( MemberExpr * memberExpr ) {
[79970ed]	1122	if ( ! checkWarnings( function ) ) return;
[c8dfcd3]	1123	if ( ! isCtor ) return;
[79970ed]	1124
	1125	if ( ApplicationExpr * deref = dynamic_cast< ApplicationExpr * >( memberExpr->get_aggregate() ) ) {
	1126	if ( getFunctionName( deref ) == "*?" && deref->get_args().size() == 1 ) {
	1127	if ( VariableExpr * varExpr = dynamic_cast< VariableExpr * >( deref->get_args().front() ) ) {
	1128	if ( varExpr->get_var() == thisParam ) {
	1129	if ( unhandled.count( memberExpr->get_member() ) ) {
	1130	// emit a warning because a member was used before it was constructed
[64ac636]	1131	usedUninit.insert( { memberExpr->get_member(), memberExpr->location } );
[79970ed]	1132	}
	1133	}
	1134	}
	1135	}
	1136	}
	1137	Parent::visit( memberExpr );
	1138	}
[3906301]	1139
	1140	template< typename Visitor, typename... Params >
[64ac636]	1141	void error( Visitor & v, CodeLocation loc, const Params &... params ) {
	1142	SemanticError err( toString( params... ) );
	1143	err.set_location( loc );
	1144	v.errors.append( err );
[3906301]	1145	}
	1146
	1147	template< typename... Params >
[64ac636]	1148	void GenStructMemberCalls::emit( CodeLocation loc, const Params &... params ) {
[3906301]	1149	// toggle warnings vs. errors here.
	1150	// warn( params... );
[64ac636]	1151	error( *this, loc, params... );
[3906301]	1152	}
[c8dfcd3]	1153
	1154	DeclarationWithType * MutatingResolver::mutate( ObjectDecl *objectDecl ) {
	1155	// add object to the indexer assumes that there will be no name collisions
	1156	// in generated code. If this changes, add mutate methods for entities with
	1157	// scope and call {enter,leave}Scope explicitly.
	1158	objectDecl->accept( indexer );
	1159	return objectDecl;
	1160	}
	1161
	1162	Expression* MutatingResolver::mutate( UntypedExpr *untypedExpr ) {
	1163	return safe_dynamic_cast< ApplicationExpr * >( ResolvExpr::findVoidExpression( untypedExpr, indexer ) );
	1164	}
[b6fe7e6]	1165
	1166	Expression * FixCtorExprs::mutate( ConstructorExpr * ctorExpr ) {
	1167	static UniqueName tempNamer( "_tmp_ctor_expr" );
[f0121d7]	1168	// xxx - is the size check necessary?
[906e24d]	1169	assert( ctorExpr->has_result() && ctorExpr->get_result()->size() == 1 );
[b7b8674]	1170
	1171	// xxx - ideally we would reuse the temporary generated from the copy constructor passes from within firstArg if it exists and not generate a temporary if it's unnecessary.
[68fe077a]	1172	ObjectDecl * tmp = new ObjectDecl( tempNamer.newName(), Type::StorageClasses(), LinkageSpec::C, nullptr, ctorExpr->get_result()->clone(), nullptr );
[b6fe7e6]	1173	addDeclaration( tmp );
	1174
[627f585]	1175	// xxx - this can be TupleAssignExpr now. Need to properly handle this case.
[b6fe7e6]	1176	ApplicationExpr * callExpr = safe_dynamic_cast< ApplicationExpr * > ( ctorExpr->get_callExpr() );
	1177	TypeSubstitution * env = ctorExpr->get_env();
	1178	ctorExpr->set_callExpr( nullptr );
	1179	ctorExpr->set_env( nullptr );
	1180
	1181	Expression *& firstArg = callExpr->get_args().front();
	1182	UntypedExpr * assign = new UntypedExpr( new NameExpr( "?=?" ) );
	1183	assign->get_args().push_back( new VariableExpr( tmp ) );
	1184	assign->get_args().push_back( firstArg );
[906e24d]	1185	assign->set_result( ctorExpr->get_result()->clone() );
[b6fe7e6]	1186	firstArg = assign;
	1187
	1188	CommaExpr * commaExpr = new CommaExpr( callExpr, new VariableExpr( tmp ) );
	1189	commaExpr->set_env( env );
	1190	delete ctorExpr;
	1191	return commaExpr;
	1192	}
[c2931ea]	1193	} // namespace
[71f4e4f]	1194	} // namespace InitTweak
	1195
	1196	// Local Variables: //
	1197	// tab-width: 4 //
	1198	// mode: c++ //
	1199	// compile-command: "make install" //
	1200	// End: //

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