[490fb92e] | 1 | #include "FixInit.h" |
---|
| 2 | |
---|
| 3 | #include <stddef.h> // for NULL |
---|
| 4 | #include <algorithm> // for set_difference, copy_if |
---|
| 5 | #include <cassert> // for assert, strict_dynamic_cast |
---|
| 6 | #include <iostream> // for operator<<, ostream, basic_ost... |
---|
| 7 | #include <iterator> // for insert_iterator, back_inserter |
---|
| 8 | #include <list> // for _List_iterator, list, list<>::... |
---|
| 9 | #include <map> // for _Rb_tree_iterator, _Rb_tree_co... |
---|
| 10 | #include <memory> // for allocator_traits<>::value_type |
---|
| 11 | #include <set> // for set, set<>::value_type |
---|
| 12 | #include <unordered_map> // for unordered_map, unordered_map<>... |
---|
| 13 | #include <unordered_set> // for unordered_set |
---|
| 14 | #include <utility> // for pair |
---|
| 15 | |
---|
[fb4dc28] | 16 | #include "AST/DeclReplacer.hpp" |
---|
| 17 | #include "AST/Expr.hpp" |
---|
[e01eb4a] | 18 | #include "AST/Inspect.hpp" // for getFunction, getPointerBase, g... |
---|
[fb4dc28] | 19 | #include "AST/Node.hpp" |
---|
| 20 | #include "AST/Pass.hpp" |
---|
| 21 | #include "AST/Print.hpp" |
---|
| 22 | #include "AST/SymbolTable.hpp" |
---|
| 23 | #include "AST/Type.hpp" |
---|
[b29a1e8] | 24 | #include "CodeGen/OperatorTable.h" // for isConstructor, isCtorDtor, isD... |
---|
[490fb92e] | 25 | #include "Common/SemanticError.h" // for SemanticError |
---|
[9feb34b] | 26 | #include "Common/ToString.hpp" // for toCString |
---|
[490fb92e] | 27 | #include "Common/UniqueName.h" // for UniqueName |
---|
| 28 | #include "FixGlobalInit.h" // for fixGlobalInit |
---|
| 29 | #include "GenInit.h" // for genCtorDtor |
---|
| 30 | #include "GenPoly/GenPoly.h" // for getFunctionType |
---|
| 31 | #include "ResolvExpr/Resolver.h" // for findVoidExpression |
---|
[e563edf] | 32 | #include "ResolvExpr/Unify.h" // for typesCompatible |
---|
[fb4dc28] | 33 | #include "SymTab/GenImplicitCall.hpp" // for genImplicitCall |
---|
[490fb92e] | 34 | |
---|
| 35 | extern bool ctordtorp; // print all debug |
---|
| 36 | extern bool ctorp; // print ctor debug |
---|
| 37 | extern bool cpctorp; // print copy ctor debug |
---|
| 38 | extern bool dtorp; // print dtor debug |
---|
| 39 | #define PRINT( text ) if ( ctordtorp ) { text } |
---|
| 40 | #define CP_CTOR_PRINT( text ) if ( ctordtorp || cpctorp ) { text } |
---|
| 41 | #define DTOR_PRINT( text ) if ( ctordtorp || dtorp ) { text } |
---|
| 42 | |
---|
| 43 | namespace InitTweak { |
---|
[0e707bd] | 44 | namespace { |
---|
[fb4dc28] | 45 | |
---|
| 46 | // Shallow copy the pointer list for return. |
---|
| 47 | std::vector<ast::ptr<ast::TypeDecl>> getGenericParams( const ast::Type * t ) { |
---|
| 48 | if ( auto inst = dynamic_cast<const ast::StructInstType *>( t ) ) { |
---|
| 49 | return inst->base->params; |
---|
| 50 | } |
---|
| 51 | if ( auto inst = dynamic_cast<const ast::UnionInstType *>( t ) ) { |
---|
| 52 | return inst->base->params; |
---|
| 53 | } |
---|
| 54 | return {}; |
---|
| 55 | } |
---|
| 56 | |
---|
| 57 | /// Given type T, generate type of default ctor/dtor, i.e. function type void (*) (T &). |
---|
| 58 | ast::FunctionDecl * genDefaultFunc( |
---|
| 59 | const CodeLocation loc, |
---|
| 60 | const std::string fname, |
---|
| 61 | const ast::Type * paramType, |
---|
| 62 | bool maybePolymorphic = true) { |
---|
| 63 | std::vector<ast::ptr<ast::TypeDecl>> typeParams; |
---|
| 64 | if ( maybePolymorphic ) typeParams = getGenericParams( paramType ); |
---|
| 65 | auto dstParam = new ast::ObjectDecl( loc, |
---|
| 66 | "_dst", |
---|
| 67 | new ast::ReferenceType( paramType ), |
---|
| 68 | nullptr, |
---|
| 69 | {}, |
---|
| 70 | ast::Linkage::Cforall |
---|
| 71 | ); |
---|
| 72 | return new ast::FunctionDecl( loc, |
---|
| 73 | fname, |
---|
| 74 | std::move(typeParams), |
---|
| 75 | {dstParam}, |
---|
| 76 | {}, |
---|
| 77 | new ast::CompoundStmt(loc), |
---|
| 78 | {}, |
---|
| 79 | ast::Linkage::Cforall |
---|
| 80 | ); |
---|
| 81 | } |
---|
| 82 | |
---|
[0e707bd] | 83 | struct SelfAssignChecker { |
---|
| 84 | void previsit( const ast::ApplicationExpr * appExpr ); |
---|
| 85 | }; |
---|
| 86 | |
---|
| 87 | struct StmtExprResult { |
---|
| 88 | const ast::StmtExpr * previsit( const ast::StmtExpr * stmtExpr ); |
---|
| 89 | }; |
---|
| 90 | |
---|
| 91 | /// wrap function application expressions as ImplicitCopyCtorExpr nodes so that it is easy to identify which |
---|
| 92 | /// function calls need their parameters to be copy constructed |
---|
[9e23b446] | 93 | struct InsertImplicitCalls : public ast::WithShortCircuiting { |
---|
[0e707bd] | 94 | const ast::Expr * postvisit( const ast::ApplicationExpr * appExpr ); |
---|
| 95 | |
---|
| 96 | // only handles each UniqueExpr once |
---|
| 97 | // if order of visit does not change, this should be safe |
---|
| 98 | void previsit (const ast::UniqueExpr *); |
---|
| 99 | |
---|
| 100 | std::unordered_set<decltype(ast::UniqueExpr::id)> visitedIds; |
---|
| 101 | }; |
---|
| 102 | |
---|
| 103 | /// generate temporary ObjectDecls for each argument and return value of each ImplicitCopyCtorExpr, |
---|
| 104 | /// generate/resolve copy construction expressions for each, and generate/resolve destructors for both |
---|
| 105 | /// arguments and return value temporaries |
---|
[39d8950] | 106 | struct ResolveCopyCtors final : public ast::WithGuards, public ast::WithStmtsToAdd<>, public ast::WithSymbolTable, public ast::WithShortCircuiting, public ast::WithVisitorRef<ResolveCopyCtors>, public ast::WithConstTranslationUnit { |
---|
[0e707bd] | 107 | const ast::Expr * postvisit( const ast::ImplicitCopyCtorExpr * impCpCtorExpr ); |
---|
| 108 | const ast::StmtExpr * previsit( const ast::StmtExpr * stmtExpr ); |
---|
| 109 | const ast::UniqueExpr * previsit( const ast::UniqueExpr * unqExpr ); |
---|
| 110 | |
---|
| 111 | /// handles distant mutations of environment manually. |
---|
| 112 | /// WithConstTypeSubstitution cannot remember where the environment is from |
---|
| 113 | |
---|
| 114 | /// MUST be called at start of overload previsit |
---|
| 115 | void previsit( const ast::Expr * expr); |
---|
| 116 | /// MUST be called at return of overload postvisit |
---|
| 117 | const ast::Expr * postvisit(const ast::Expr * expr); |
---|
| 118 | |
---|
| 119 | /// create and resolve ctor/dtor expression: fname(var, [cpArg]) |
---|
| 120 | const ast::Expr * makeCtorDtor( const std::string & fname, const ast::ObjectDecl * var, const ast::Expr * cpArg = nullptr ); |
---|
| 121 | /// true if type does not need to be copy constructed to ensure correctness |
---|
| 122 | bool skipCopyConstruct( const ast::Type * type ); |
---|
| 123 | ast::ptr< ast::Expr > copyConstructArg( const ast::Expr * arg, const ast::ImplicitCopyCtorExpr * impCpCtorExpr, const ast::Type * formal ); |
---|
| 124 | ast::Expr * destructRet( const ast::ObjectDecl * ret, const ast::Expr * arg ); |
---|
| 125 | private: |
---|
| 126 | /// hack to implement WithTypeSubstitution while conforming to mutation safety. |
---|
[397c4392] | 127 | ast::TypeSubstitution * env = nullptr; |
---|
| 128 | bool envModified = false; |
---|
[0e707bd] | 129 | }; |
---|
| 130 | |
---|
| 131 | /// collects constructed object decls - used as a base class |
---|
| 132 | struct ObjDeclCollector : public ast::WithGuards, public ast::WithShortCircuiting { |
---|
| 133 | // use ordered data structure to maintain ordering for set_difference and for consistent error messages |
---|
| 134 | typedef std::list< const ast::ObjectDecl * > ObjectSet; |
---|
| 135 | void previsit( const ast::CompoundStmt *compoundStmt ); |
---|
| 136 | void previsit( const ast::DeclStmt *stmt ); |
---|
| 137 | |
---|
| 138 | // don't go into other functions |
---|
| 139 | void previsit( const ast::FunctionDecl * ) { visit_children = false; } |
---|
| 140 | |
---|
[fb4dc28] | 141 | protected: |
---|
[0e707bd] | 142 | ObjectSet curVars; |
---|
| 143 | }; |
---|
| 144 | |
---|
| 145 | // debug |
---|
| 146 | template<typename ObjectSet> |
---|
| 147 | struct PrintSet { |
---|
| 148 | PrintSet( const ObjectSet & objs ) : objs( objs ) {} |
---|
| 149 | const ObjectSet & objs; |
---|
| 150 | }; |
---|
| 151 | template<typename ObjectSet> |
---|
| 152 | PrintSet<ObjectSet> printSet( const ObjectSet & objs ) { return PrintSet<ObjectSet>( objs ); } |
---|
| 153 | template<typename ObjectSet> |
---|
| 154 | std::ostream & operator<<( std::ostream & out, const PrintSet<ObjectSet> & set) { |
---|
| 155 | out << "{ "; |
---|
| 156 | for ( auto & obj : set.objs ) { |
---|
| 157 | out << obj->name << ", " ; |
---|
| 158 | } // for |
---|
| 159 | out << " }"; |
---|
| 160 | return out; |
---|
| 161 | } |
---|
[490fb92e] | 162 | |
---|
[0e707bd] | 163 | struct LabelFinder final : public ObjDeclCollector { |
---|
| 164 | typedef std::map< std::string, ObjectSet > LabelMap; |
---|
| 165 | // map of Label -> live variables at that label |
---|
| 166 | LabelMap vars; |
---|
[490fb92e] | 167 | |
---|
[0e707bd] | 168 | typedef ObjDeclCollector Parent; |
---|
| 169 | using Parent::previsit; |
---|
| 170 | void previsit( const ast::Stmt * stmt ); |
---|
[490fb92e] | 171 | |
---|
[0e707bd] | 172 | void previsit( const ast::CompoundStmt *compoundStmt ); |
---|
| 173 | void previsit( const ast::DeclStmt *stmt ); |
---|
| 174 | }; |
---|
[490fb92e] | 175 | |
---|
[0e707bd] | 176 | /// insert destructor calls at the appropriate places. must happen before CtorInit nodes are removed |
---|
| 177 | /// (currently by FixInit) |
---|
| 178 | struct InsertDtors final : public ObjDeclCollector, public ast::WithStmtsToAdd<> { |
---|
| 179 | typedef std::list< ObjectDecl * > OrderedDecls; |
---|
| 180 | typedef std::list< OrderedDecls > OrderedDeclsStack; |
---|
[490fb92e] | 181 | |
---|
[0e707bd] | 182 | InsertDtors( ast::Pass<LabelFinder> & finder ) : finder( finder ), labelVars( finder.core.vars ) {} |
---|
[490fb92e] | 183 | |
---|
[0e707bd] | 184 | typedef ObjDeclCollector Parent; |
---|
| 185 | using Parent::previsit; |
---|
[490fb92e] | 186 | |
---|
[0e707bd] | 187 | void previsit( const ast::FunctionDecl * funcDecl ); |
---|
[490fb92e] | 188 | |
---|
[0e707bd] | 189 | void previsit( const ast::BranchStmt * stmt ); |
---|
| 190 | private: |
---|
| 191 | void handleGoto( const ast::BranchStmt * stmt ); |
---|
[490fb92e] | 192 | |
---|
[0e707bd] | 193 | ast::Pass<LabelFinder> & finder; |
---|
| 194 | LabelFinder::LabelMap & labelVars; |
---|
| 195 | OrderedDeclsStack reverseDeclOrder; |
---|
| 196 | }; |
---|
[490fb92e] | 197 | |
---|
[0e707bd] | 198 | /// expand each object declaration to use its constructor after it is declared. |
---|
| 199 | struct FixInit : public ast::WithStmtsToAdd<> { |
---|
[293dc1c] | 200 | static void fixInitializers( ast::TranslationUnit &translationUnit ); |
---|
[490fb92e] | 201 | |
---|
[0e707bd] | 202 | const ast::DeclWithType * postvisit( const ast::ObjectDecl *objDecl ); |
---|
[490fb92e] | 203 | |
---|
[0e707bd] | 204 | std::list< ast::ptr< ast::Decl > > staticDtorDecls; |
---|
| 205 | }; |
---|
[490fb92e] | 206 | |
---|
[0e707bd] | 207 | /// generate default/copy ctor and dtor calls for user-defined struct ctor/dtors |
---|
| 208 | /// for any member that is missing a corresponding ctor/dtor call. |
---|
| 209 | /// error if a member is used before constructed |
---|
[39d8950] | 210 | struct GenStructMemberCalls final : public ast::WithGuards, public ast::WithShortCircuiting, public ast::WithSymbolTable, public ast::WithVisitorRef<GenStructMemberCalls>, public ast::WithConstTranslationUnit { |
---|
[0e707bd] | 211 | void previsit( const ast::FunctionDecl * funcDecl ); |
---|
| 212 | const ast::DeclWithType * postvisit( const ast::FunctionDecl * funcDecl ); |
---|
[490fb92e] | 213 | |
---|
[0e707bd] | 214 | void previsit( const ast::MemberExpr * memberExpr ); |
---|
| 215 | void previsit( const ast::ApplicationExpr * appExpr ); |
---|
[490fb92e] | 216 | |
---|
[0e707bd] | 217 | /// Note: this post mutate used to be in a separate visitor. If this pass breaks, one place to examine is whether it is |
---|
| 218 | /// okay for this part of the recursion to occur alongside the rest. |
---|
| 219 | const ast::Expr * postvisit( const ast::UntypedExpr * expr ); |
---|
[490fb92e] | 220 | |
---|
[0e707bd] | 221 | SemanticErrorException errors; |
---|
[fb4dc28] | 222 | private: |
---|
[0e707bd] | 223 | template< typename... Params > |
---|
| 224 | void emit( CodeLocation, const Params &... params ); |
---|
| 225 | |
---|
| 226 | ast::FunctionDecl * function = nullptr; |
---|
| 227 | std::set< const ast::DeclWithType * > unhandled; |
---|
| 228 | std::map< const ast::DeclWithType *, CodeLocation > usedUninit; |
---|
| 229 | const ast::ObjectDecl * thisParam = nullptr; |
---|
| 230 | bool isCtor = false; // true if current function is a constructor |
---|
| 231 | const ast::StructDecl * structDecl = nullptr; |
---|
| 232 | }; |
---|
| 233 | |
---|
| 234 | /// expands ConstructorExpr nodes into comma expressions, using a temporary for the first argument |
---|
[39d8950] | 235 | struct FixCtorExprs final : public ast::WithDeclsToAdd<>, public ast::WithSymbolTable, public ast::WithShortCircuiting, public ast::WithConstTranslationUnit { |
---|
[0e707bd] | 236 | const ast::Expr * postvisit( const ast::ConstructorExpr * ctorExpr ); |
---|
| 237 | }; |
---|
| 238 | |
---|
| 239 | /// add CompoundStmts around top-level expressions so that temporaries are destroyed in the correct places. |
---|
| 240 | struct SplitExpressions : public ast::WithShortCircuiting { |
---|
| 241 | ast::Stmt * postvisit( const ast::ExprStmt * stmt ); |
---|
| 242 | void previsit( const ast::TupleAssignExpr * expr ); |
---|
| 243 | }; |
---|
| 244 | } // namespace |
---|
| 245 | |
---|
[293dc1c] | 246 | void fix( ast::TranslationUnit & translationUnit, bool inLibrary ) { |
---|
[0e707bd] | 247 | ast::Pass<SelfAssignChecker>::run( translationUnit ); |
---|
| 248 | |
---|
| 249 | // fixes StmtExpr to properly link to their resulting expression |
---|
| 250 | ast::Pass<StmtExprResult>::run( translationUnit ); |
---|
| 251 | |
---|
| 252 | // fixes ConstructorInit for global variables. should happen before fixInitializers. |
---|
| 253 | InitTweak::fixGlobalInit( translationUnit, inLibrary ); |
---|
| 254 | |
---|
| 255 | // must happen before ResolveCopyCtors because temporaries have to be inserted into the correct scope |
---|
| 256 | ast::Pass<SplitExpressions>::run( translationUnit ); |
---|
| 257 | |
---|
| 258 | ast::Pass<InsertImplicitCalls>::run( translationUnit ); |
---|
| 259 | |
---|
| 260 | // Needs to happen before ResolveCopyCtors, because argument/return temporaries should not be considered in |
---|
| 261 | // error checking branch statements |
---|
| 262 | { |
---|
| 263 | ast::Pass<LabelFinder> finder; |
---|
| 264 | ast::Pass<InsertDtors>::run( translationUnit, finder ); |
---|
[490fb92e] | 265 | } |
---|
| 266 | |
---|
[0e707bd] | 267 | ast::Pass<ResolveCopyCtors>::run( translationUnit ); |
---|
| 268 | FixInit::fixInitializers( translationUnit ); |
---|
| 269 | ast::Pass<GenStructMemberCalls>::run( translationUnit ); |
---|
| 270 | |
---|
| 271 | // Needs to happen after GenStructMemberCalls, since otherwise member constructors exprs |
---|
| 272 | // don't have the correct form, and a member can be constructed more than once. |
---|
| 273 | ast::Pass<FixCtorExprs>::run( translationUnit ); |
---|
| 274 | } |
---|
| 275 | |
---|
| 276 | namespace { |
---|
| 277 | /// find and return the destructor used in `input`. If `input` is not a simple destructor call, generate a thunk |
---|
| 278 | /// that wraps the destructor, insert it into `stmtsToAdd` and return the new function declaration |
---|
| 279 | const ast::DeclWithType * getDtorFunc( const ast::ObjectDecl * objDecl, const ast::Stmt * input, std::list< ast::ptr<ast::Stmt> > & stmtsToAdd ) { |
---|
| 280 | const CodeLocation loc = input->location; |
---|
| 281 | // unwrap implicit statement wrapper |
---|
| 282 | // Statement * dtor = input; |
---|
| 283 | assert( input ); |
---|
| 284 | // std::list< const ast::Expr * > matches; |
---|
| 285 | auto matches = collectCtorDtorCalls( input ); |
---|
| 286 | |
---|
| 287 | if ( dynamic_cast< const ast::ExprStmt * >( input ) ) { |
---|
| 288 | // only one destructor call in the expression |
---|
| 289 | if ( matches.size() == 1 ) { |
---|
| 290 | auto func = getFunction( matches.front() ); |
---|
| 291 | assertf( func, "getFunction failed to find function in %s", toString( matches.front() ).c_str() ); |
---|
| 292 | |
---|
| 293 | // cleanup argument must be a function, not an object (including function pointer) |
---|
| 294 | if ( auto dtorFunc = dynamic_cast< const ast::FunctionDecl * > ( func ) ) { |
---|
| 295 | if ( dtorFunc->type->forall.empty() ) { |
---|
| 296 | // simple case where the destructor is a monomorphic function call - can simply |
---|
| 297 | // use that function as the cleanup function. |
---|
| 298 | return func; |
---|
[490fb92e] | 299 | } |
---|
| 300 | } |
---|
| 301 | } |
---|
| 302 | } |
---|
| 303 | |
---|
[0e707bd] | 304 | // otherwise the cleanup is more complicated - need to build a single argument cleanup function that |
---|
| 305 | // wraps the more complicated code. |
---|
| 306 | static UniqueName dtorNamer( "__cleanup_dtor" ); |
---|
| 307 | std::string name = dtorNamer.newName(); |
---|
[fb4dc28] | 308 | ast::FunctionDecl * dtorFunc = genDefaultFunc( loc, name, objDecl->type->stripReferences(), false ); |
---|
[0e707bd] | 309 | stmtsToAdd.push_back( new ast::DeclStmt(loc, dtorFunc ) ); |
---|
| 310 | |
---|
| 311 | // the original code contains uses of objDecl - replace them with the newly generated 'this' parameter. |
---|
| 312 | const ast::ObjectDecl * thisParam = getParamThis( dtorFunc ); |
---|
| 313 | const ast::Expr * replacement = new ast::VariableExpr( loc, thisParam ); |
---|
| 314 | |
---|
| 315 | auto base = replacement->result->stripReferences(); |
---|
| 316 | if ( dynamic_cast< const ast::ArrayType * >( base ) || dynamic_cast< const ast::TupleType * > ( base ) ) { |
---|
| 317 | // need to cast away reference for array types, since the destructor is generated without the reference type, |
---|
| 318 | // and for tuple types since tuple indexing does not work directly on a reference |
---|
| 319 | replacement = new ast::CastExpr( replacement, base ); |
---|
[490fb92e] | 320 | } |
---|
[0e707bd] | 321 | auto dtor = ast::DeclReplacer::replace( input, ast::DeclReplacer::ExprMap{ std::make_pair( objDecl, replacement ) } ); |
---|
| 322 | auto mutStmts = dtorFunc->stmts.get_and_mutate(); |
---|
| 323 | mutStmts->push_back(strict_dynamic_cast<const ast::Stmt *>( dtor )); |
---|
| 324 | dtorFunc->stmts = mutStmts; |
---|
[490fb92e] | 325 | |
---|
[0e707bd] | 326 | return dtorFunc; |
---|
| 327 | } |
---|
[490fb92e] | 328 | |
---|
[293dc1c] | 329 | void FixInit::fixInitializers( ast::TranslationUnit & translationUnit ) { |
---|
[0e707bd] | 330 | ast::Pass<FixInit> fixer; |
---|
| 331 | |
---|
| 332 | // can't use mutateAll, because need to insert declarations at top-level |
---|
| 333 | // can't use DeclMutator, because sometimes need to insert IfStmt, etc. |
---|
| 334 | SemanticErrorException errors; |
---|
[293dc1c] | 335 | for ( auto i = translationUnit.decls.begin(); i != translationUnit.decls.end(); ++i ) { |
---|
[0e707bd] | 336 | try { |
---|
| 337 | // maybeAccept( *i, fixer ); translationUnit should never contain null |
---|
| 338 | *i = (*i)->accept(fixer); |
---|
[293dc1c] | 339 | translationUnit.decls.splice( i, fixer.core.staticDtorDecls ); |
---|
[0e707bd] | 340 | } catch( SemanticErrorException &e ) { |
---|
| 341 | errors.append( e ); |
---|
| 342 | } // try |
---|
| 343 | } // for |
---|
| 344 | if ( ! errors.isEmpty() ) { |
---|
| 345 | throw errors; |
---|
| 346 | } // if |
---|
| 347 | } |
---|
[490fb92e] | 348 | |
---|
[0e707bd] | 349 | const ast::StmtExpr * StmtExprResult::previsit( const ast::StmtExpr * stmtExpr ) { |
---|
| 350 | // we might loose the result expression here so add a pointer to trace back |
---|
| 351 | assert( stmtExpr->result ); |
---|
| 352 | const ast::Type * result = stmtExpr->result; |
---|
| 353 | if ( ! result->isVoid() ) { |
---|
| 354 | auto mutExpr = mutate(stmtExpr); |
---|
| 355 | const ast::CompoundStmt * body = mutExpr->stmts; |
---|
| 356 | assert( ! body->kids.empty() ); |
---|
| 357 | mutExpr->resultExpr = body->kids.back().strict_as<ast::ExprStmt>(); |
---|
| 358 | return mutExpr; |
---|
[490fb92e] | 359 | } |
---|
[0e707bd] | 360 | return stmtExpr; |
---|
| 361 | } |
---|
[490fb92e] | 362 | |
---|
[0e707bd] | 363 | ast::Stmt * SplitExpressions::postvisit( const ast::ExprStmt * stmt ) { |
---|
| 364 | // wrap each top-level ExprStmt in a block so that destructors for argument and return temporaries are destroyed |
---|
| 365 | // in the correct places |
---|
| 366 | ast::CompoundStmt * ret = new ast::CompoundStmt( stmt->location, { stmt } ); |
---|
| 367 | return ret; |
---|
| 368 | } |
---|
[490fb92e] | 369 | |
---|
[0e707bd] | 370 | void SplitExpressions::previsit( const ast::TupleAssignExpr * ) { |
---|
| 371 | // don't do this within TupleAssignExpr, since it is already broken up into multiple expressions |
---|
| 372 | visit_children = false; |
---|
| 373 | } |
---|
[490fb92e] | 374 | |
---|
[0e707bd] | 375 | // Relatively simple structural comparison for expressions, needed to determine |
---|
| 376 | // if two expressions are "the same" (used to determine if self assignment occurs) |
---|
| 377 | struct StructuralChecker { |
---|
[6a036eb] | 378 | // Strip all casts and then dynamic_cast. |
---|
| 379 | template<typename T> |
---|
| 380 | static const T * cast( const ast::Expr * expr ) { |
---|
[0e707bd] | 381 | // this might be too permissive. It's possible that only particular casts are relevant. |
---|
| 382 | while ( auto cast = dynamic_cast< const ast::CastExpr * >( expr ) ) { |
---|
| 383 | expr = cast->arg; |
---|
[490fb92e] | 384 | } |
---|
[6a036eb] | 385 | return dynamic_cast< const T * >( expr ); |
---|
[0e707bd] | 386 | } |
---|
[490fb92e] | 387 | |
---|
[0e707bd] | 388 | void previsit( const ast::Expr * ) { |
---|
| 389 | // anything else does not qualify |
---|
[6a036eb] | 390 | result = false; |
---|
[0e707bd] | 391 | } |
---|
[490fb92e] | 392 | |
---|
[0e707bd] | 393 | // ignore casts |
---|
| 394 | void previsit( const ast::CastExpr * ) {} |
---|
| 395 | |
---|
| 396 | void previsit( const ast::MemberExpr * memExpr ) { |
---|
[6a036eb] | 397 | if ( auto otherMember = cast< ast::MemberExpr >( other ) ) { |
---|
[0e707bd] | 398 | if ( otherMember->member == memExpr->member ) { |
---|
| 399 | other = otherMember->aggregate; |
---|
| 400 | return; |
---|
[490fb92e] | 401 | } |
---|
| 402 | } |
---|
[6a036eb] | 403 | result = false; |
---|
[0e707bd] | 404 | } |
---|
[490fb92e] | 405 | |
---|
[0e707bd] | 406 | void previsit( const ast::VariableExpr * varExpr ) { |
---|
[6a036eb] | 407 | if ( auto otherVar = cast< ast::VariableExpr >( other ) ) { |
---|
[0e707bd] | 408 | if ( otherVar->var == varExpr->var ) { |
---|
[490fb92e] | 409 | return; |
---|
| 410 | } |
---|
| 411 | } |
---|
[6a036eb] | 412 | result = false; |
---|
[0e707bd] | 413 | } |
---|
[490fb92e] | 414 | |
---|
[0e707bd] | 415 | void previsit( const ast::AddressExpr * ) { |
---|
[6a036eb] | 416 | if ( auto addrExpr = cast< ast::AddressExpr >( other ) ) { |
---|
[0e707bd] | 417 | other = addrExpr->arg; |
---|
| 418 | return; |
---|
| 419 | } |
---|
[6a036eb] | 420 | result = false; |
---|
[490fb92e] | 421 | } |
---|
| 422 | |
---|
[6a036eb] | 423 | const ast::Expr * other; |
---|
| 424 | bool result = true; |
---|
| 425 | StructuralChecker( const ast::Expr * other ) : other(other) {} |
---|
[0e707bd] | 426 | }; |
---|
| 427 | |
---|
| 428 | bool structurallySimilar( const ast::Expr * e1, const ast::Expr * e2 ) { |
---|
[6a036eb] | 429 | return ast::Pass<StructuralChecker>::read( e1, e2 ); |
---|
[0e707bd] | 430 | } |
---|
| 431 | |
---|
| 432 | void SelfAssignChecker::previsit( const ast::ApplicationExpr * appExpr ) { |
---|
| 433 | auto function = getFunction( appExpr ); |
---|
[4a8f150] | 434 | // Doesn't use isAssignment, because ?+=?, etc. should not count as self-assignment. |
---|
| 435 | if ( function->name == "?=?" && appExpr->args.size() == 2 |
---|
| 436 | // Check for structural similarity (same variable use, ignore casts, etc. |
---|
| 437 | // (but does not look too deeply, anything looking like a function is off limits). |
---|
| 438 | && structurallySimilar( appExpr->args.front(), appExpr->args.back() ) ) { |
---|
| 439 | SemanticWarning( appExpr->location, Warning::SelfAssignment, toCString( appExpr->args.front() ) ); |
---|
[490fb92e] | 440 | } |
---|
[0e707bd] | 441 | } |
---|
[490fb92e] | 442 | |
---|
[0e707bd] | 443 | const ast::Expr * InsertImplicitCalls::postvisit( const ast::ApplicationExpr * appExpr ) { |
---|
| 444 | if ( auto function = appExpr->func.as<ast::VariableExpr>() ) { |
---|
| 445 | if ( function->var->linkage.is_builtin ) { |
---|
| 446 | // optimization: don't need to copy construct in order to call intrinsic functions |
---|
| 447 | return appExpr; |
---|
| 448 | } else if ( auto funcDecl = function->var.as<ast::DeclWithType>() ) { |
---|
| 449 | auto ftype = dynamic_cast< const ast::FunctionType * >( GenPoly::getFunctionType( funcDecl->get_type() ) ); |
---|
| 450 | assertf( ftype, "Function call without function type: %s", toString( funcDecl ).c_str() ); |
---|
| 451 | if ( CodeGen::isConstructor( funcDecl->name ) && ftype->params.size() == 2 ) { |
---|
| 452 | auto t1 = getPointerBase( ftype->params.front() ); |
---|
| 453 | auto t2 = ftype->params.back(); |
---|
| 454 | assert( t1 ); |
---|
| 455 | |
---|
| 456 | if ( ResolvExpr::typesCompatible( t1, t2 ) ) { |
---|
| 457 | // optimization: don't need to copy construct in order to call a copy constructor |
---|
[490fb92e] | 458 | return appExpr; |
---|
| 459 | } // if |
---|
[0e707bd] | 460 | } else if ( CodeGen::isDestructor( funcDecl->name ) ) { |
---|
| 461 | // correctness: never copy construct arguments to a destructor |
---|
| 462 | return appExpr; |
---|
[490fb92e] | 463 | } // if |
---|
| 464 | } // if |
---|
[0e707bd] | 465 | } // if |
---|
| 466 | CP_CTOR_PRINT( std::cerr << "InsertImplicitCalls: adding a wrapper " << appExpr << std::endl; ) |
---|
| 467 | |
---|
| 468 | // wrap each function call so that it is easy to identify nodes that have to be copy constructed |
---|
| 469 | ast::ptr<ast::TypeSubstitution> tmp = appExpr->env; |
---|
| 470 | auto mutExpr = mutate(appExpr); |
---|
| 471 | mutExpr->env = nullptr; |
---|
| 472 | |
---|
| 473 | auto expr = new ast::ImplicitCopyCtorExpr( appExpr->location, mutExpr ); |
---|
[8060b2b] | 474 | // Move the type substitution to the new top-level. The substitution |
---|
| 475 | // is needed to obtain the type of temporary variables so that copy |
---|
| 476 | // constructor calls can be resolved. |
---|
[0e707bd] | 477 | expr->env = tmp; |
---|
| 478 | return expr; |
---|
| 479 | } |
---|
[490fb92e] | 480 | |
---|
[0e707bd] | 481 | void ResolveCopyCtors::previsit(const ast::Expr * expr) { |
---|
[8060b2b] | 482 | if ( nullptr == expr->env ) { |
---|
| 483 | return; |
---|
[490fb92e] | 484 | } |
---|
[8060b2b] | 485 | GuardValue( env ) = expr->env->clone(); |
---|
| 486 | GuardValue( envModified ) = false; |
---|
[0e707bd] | 487 | } |
---|
[490fb92e] | 488 | |
---|
[0e707bd] | 489 | const ast::Expr * ResolveCopyCtors::postvisit(const ast::Expr * expr) { |
---|
[8060b2b] | 490 | // No local environment, skip. |
---|
| 491 | if ( nullptr == expr->env ) { |
---|
| 492 | return expr; |
---|
| 493 | // Environment was modified, mutate and replace. |
---|
| 494 | } else if ( envModified ) { |
---|
| 495 | auto mutExpr = mutate(expr); |
---|
| 496 | mutExpr->env = env; |
---|
| 497 | return mutExpr; |
---|
| 498 | // Environment was not mutated, delete the shallow copy before guard. |
---|
| 499 | } else { |
---|
| 500 | delete env; |
---|
[0e707bd] | 501 | return expr; |
---|
[490fb92e] | 502 | } |
---|
[0e707bd] | 503 | } |
---|
[490fb92e] | 504 | |
---|
[0e707bd] | 505 | bool ResolveCopyCtors::skipCopyConstruct( const ast::Type * type ) { return ! isConstructable( type ); } |
---|
| 506 | |
---|
| 507 | const ast::Expr * ResolveCopyCtors::makeCtorDtor( const std::string & fname, const ast::ObjectDecl * var, const ast::Expr * cpArg ) { |
---|
| 508 | assert( var ); |
---|
[8060b2b] | 509 | assert( var->isManaged() ); |
---|
| 510 | assert( !cpArg || cpArg->isManaged() ); |
---|
[0e707bd] | 511 | // arrays are not copy constructed, so this should always be an ExprStmt |
---|
| 512 | ast::ptr< ast::Stmt > stmt = genCtorDtor(var->location, fname, var, cpArg ); |
---|
| 513 | assertf( stmt, "ResolveCopyCtors: genCtorDtor returned nullptr: %s / %s / %s", fname.c_str(), toString( var ).c_str(), toString( cpArg ).c_str() ); |
---|
| 514 | auto exprStmt = stmt.strict_as<ast::ImplicitCtorDtorStmt>()->callStmt.strict_as<ast::ExprStmt>(); |
---|
| 515 | ast::ptr<ast::Expr> untyped = exprStmt->expr; // take ownership of expr |
---|
| 516 | |
---|
| 517 | // resolve copy constructor |
---|
| 518 | // should only be one alternative for copy ctor and dtor expressions, since all arguments are fixed |
---|
| 519 | // (VariableExpr and already resolved expression) |
---|
| 520 | CP_CTOR_PRINT( std::cerr << "ResolvingCtorDtor " << untyped << std::endl; ) |
---|
[39d8950] | 521 | ast::ptr<ast::Expr> resolved = ResolvExpr::findVoidExpression(untyped, { symtab, transUnit().global } ); |
---|
[0e707bd] | 522 | assert( resolved ); |
---|
| 523 | if ( resolved->env ) { |
---|
| 524 | // Extract useful information and discard new environments. Keeping them causes problems in PolyMutator passes. |
---|
| 525 | env->add( *resolved->env ); |
---|
| 526 | envModified = true; |
---|
| 527 | auto mut = mutate(resolved.get()); |
---|
| 528 | assertf(mut == resolved.get(), "newly resolved expression must be unique"); |
---|
| 529 | mut->env = nullptr; |
---|
| 530 | } // if |
---|
| 531 | if ( auto assign = resolved.as<ast::TupleAssignExpr>() ) { |
---|
| 532 | // fix newly generated StmtExpr |
---|
| 533 | previsit( assign->stmtExpr ); |
---|
| 534 | } |
---|
| 535 | return resolved.release(); |
---|
| 536 | } |
---|
[490fb92e] | 537 | |
---|
[0e707bd] | 538 | ast::ptr<ast::Expr> ResolveCopyCtors::copyConstructArg( |
---|
| 539 | const ast::Expr * arg, const ast::ImplicitCopyCtorExpr * impCpCtorExpr, const ast::Type * formal ) |
---|
| 540 | { |
---|
| 541 | static UniqueName tempNamer("_tmp_cp"); |
---|
| 542 | const CodeLocation loc = impCpCtorExpr->location; |
---|
| 543 | // CP_CTOR_PRINT( std::cerr << "Type Substitution: " << *env << std::endl; ) |
---|
| 544 | assert( arg->result ); |
---|
| 545 | ast::ptr<ast::Type> result = arg->result; |
---|
| 546 | if ( skipCopyConstruct( result ) ) return arg; // skip certain non-copyable types |
---|
| 547 | |
---|
| 548 | // type may involve type variables, so apply type substitution to get temporary variable's actual type, |
---|
| 549 | // since result type may not be substituted (e.g., if the type does not appear in the parameter list) |
---|
| 550 | // Use applyFree so that types bound in function pointers are not substituted, e.g. in forall(dtype T) void (*)(T). |
---|
| 551 | |
---|
| 552 | // xxx - this originally mutates arg->result in place. is it correct? |
---|
[8603c10] | 553 | assert( env ); |
---|
[0e707bd] | 554 | result = env->applyFree( result.get() ).node; |
---|
| 555 | auto mutResult = result.get_and_mutate(); |
---|
| 556 | mutResult->set_const(false); |
---|
| 557 | |
---|
| 558 | auto mutArg = mutate(arg); |
---|
| 559 | mutArg->result = mutResult; |
---|
| 560 | |
---|
| 561 | ast::ptr<ast::Expr> guard = mutArg; |
---|
| 562 | |
---|
[33b7d49] | 563 | ast::ptr<ast::ObjectDecl> tmp = new ast::ObjectDecl(loc, "__tmp", mutResult, nullptr ); |
---|
[0e707bd] | 564 | |
---|
| 565 | // create and resolve copy constructor |
---|
| 566 | CP_CTOR_PRINT( std::cerr << "makeCtorDtor for an argument" << std::endl; ) |
---|
| 567 | auto cpCtor = makeCtorDtor( "?{}", tmp, mutArg ); |
---|
| 568 | |
---|
| 569 | if ( auto appExpr = dynamic_cast< const ast::ApplicationExpr * >( cpCtor ) ) { |
---|
| 570 | // if the chosen constructor is intrinsic, the copy is unnecessary, so |
---|
| 571 | // don't create the temporary and don't call the copy constructor |
---|
| 572 | auto function = appExpr->func.strict_as<ast::VariableExpr>(); |
---|
| 573 | if ( function->var->linkage == ast::Linkage::Intrinsic ) { |
---|
| 574 | // arguments that need to be boxed need a temporary regardless of whether the copy constructor is intrinsic, |
---|
| 575 | // so that the object isn't changed inside of the polymorphic function |
---|
| 576 | if ( ! GenPoly::needsBoxing( formal, result, impCpCtorExpr->callExpr, env ) ) { |
---|
| 577 | // xxx - should arg->result be mutated? see comment above. |
---|
| 578 | return guard; |
---|
[490fb92e] | 579 | } |
---|
| 580 | } |
---|
[0e707bd] | 581 | } |
---|
[490fb92e] | 582 | |
---|
[0e707bd] | 583 | // set a unique name for the temporary once it's certain the call is necessary |
---|
| 584 | auto mut = tmp.get_and_mutate(); |
---|
| 585 | assertf (mut == tmp, "newly created ObjectDecl must be unique"); |
---|
| 586 | mut->name = tempNamer.newName(); |
---|
[490fb92e] | 587 | |
---|
[0e707bd] | 588 | // replace argument to function call with temporary |
---|
| 589 | stmtsToAddBefore.push_back( new ast::DeclStmt(loc, tmp ) ); |
---|
| 590 | arg = cpCtor; |
---|
| 591 | return destructRet( tmp, arg ); |
---|
[490fb92e] | 592 | |
---|
[0e707bd] | 593 | // impCpCtorExpr->dtors.push_front( makeCtorDtor( "^?{}", tmp ) ); |
---|
| 594 | } |
---|
[490fb92e] | 595 | |
---|
[0e707bd] | 596 | ast::Expr * ResolveCopyCtors::destructRet( const ast::ObjectDecl * ret, const ast::Expr * arg ) { |
---|
[39d8950] | 597 | auto global = transUnit().global; |
---|
[0e707bd] | 598 | // TODO: refactor code for generating cleanup attribute, since it's common and reused in ~3-4 places |
---|
| 599 | // check for existing cleanup attribute before adding another(?) |
---|
| 600 | // need to add __Destructor for _tmp_cp variables as well |
---|
[490fb92e] | 601 | |
---|
[39d8950] | 602 | assertf( global.dtorStruct, "Destructor generation requires __Destructor definition." ); |
---|
| 603 | assertf( global.dtorStruct->members.size() == 2, "__Destructor definition does not have expected fields." ); |
---|
| 604 | assertf( global.dtorDestroy, "Destructor generation requires __destroy_Destructor." ); |
---|
[490fb92e] | 605 | |
---|
[0e707bd] | 606 | const CodeLocation loc = ret->location; |
---|
[490fb92e] | 607 | |
---|
[0e707bd] | 608 | // generate a __Destructor for ret that calls the destructor |
---|
| 609 | auto res = makeCtorDtor( "^?{}", ret ); |
---|
| 610 | auto dtor = mutate(res); |
---|
[490fb92e] | 611 | |
---|
[0e707bd] | 612 | // if the chosen destructor is intrinsic, elide the generated dtor handler |
---|
| 613 | if ( arg && isIntrinsicCallExpr( dtor ) ) { |
---|
| 614 | return new ast::CommaExpr(loc, arg, new ast::VariableExpr(loc, ret ) ); |
---|
| 615 | } |
---|
[490fb92e] | 616 | |
---|
[0e707bd] | 617 | if ( ! dtor->env ) dtor->env = maybeClone( env ); |
---|
| 618 | auto dtorFunc = getDtorFunc( ret, new ast::ExprStmt(loc, dtor ), stmtsToAddBefore ); |
---|
[490fb92e] | 619 | |
---|
[39d8950] | 620 | auto dtorStructType = new ast::StructInstType( global.dtorStruct ); |
---|
[490fb92e] | 621 | |
---|
[0e707bd] | 622 | // what does this do??? |
---|
| 623 | dtorStructType->params.push_back( new ast::TypeExpr(loc, new ast::VoidType() ) ); |
---|
[490fb92e] | 624 | |
---|
[0e707bd] | 625 | // cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings |
---|
| 626 | auto dtorFtype = new ast::FunctionType(); |
---|
| 627 | dtorFtype->params.push_back( new ast::PointerType(new ast::VoidType( ) ) ); |
---|
| 628 | auto dtorType = new ast::PointerType( dtorFtype ); |
---|
[490fb92e] | 629 | |
---|
[0e707bd] | 630 | static UniqueName namer( "_ret_dtor" ); |
---|
| 631 | auto retDtor = new ast::ObjectDecl(loc, namer.newName(), dtorStructType, new ast::ListInit(loc, { new ast::SingleInit(loc, ast::ConstantExpr::null(loc) ), new ast::SingleInit(loc, new ast::CastExpr( new ast::VariableExpr(loc, dtorFunc ), dtorType ) ) } ) ); |
---|
[39d8950] | 632 | retDtor->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr(loc, global.dtorDestroy ) } ) ); |
---|
[0e707bd] | 633 | stmtsToAddBefore.push_back( new ast::DeclStmt(loc, retDtor ) ); |
---|
[490fb92e] | 634 | |
---|
[0e707bd] | 635 | if ( arg ) { |
---|
[39d8950] | 636 | auto member = new ast::MemberExpr(loc, global.dtorStruct->members.front().strict_as<ast::DeclWithType>(), new ast::VariableExpr(loc, retDtor ) ); |
---|
[0e707bd] | 637 | auto object = new ast::CastExpr( new ast::AddressExpr( new ast::VariableExpr(loc, ret ) ), new ast::PointerType(new ast::VoidType() ) ); |
---|
| 638 | ast::Expr * assign = createBitwiseAssignment( member, object ); |
---|
| 639 | return new ast::CommaExpr(loc, new ast::CommaExpr(loc, arg, assign ), new ast::VariableExpr(loc, ret ) ); |
---|
[490fb92e] | 640 | } |
---|
[0e707bd] | 641 | return nullptr; |
---|
| 642 | // impCpCtorExpr->get_dtors().push_front( makeCtorDtor( "^?{}", ret ) ); |
---|
| 643 | } |
---|
[490fb92e] | 644 | |
---|
[0e707bd] | 645 | const ast::Expr * ResolveCopyCtors::postvisit( const ast::ImplicitCopyCtorExpr *impCpCtorExpr ) { |
---|
| 646 | CP_CTOR_PRINT( std::cerr << "ResolveCopyCtors: " << impCpCtorExpr << std::endl; ) |
---|
| 647 | |
---|
| 648 | ast::ApplicationExpr * appExpr = mutate(impCpCtorExpr->callExpr.get()); |
---|
| 649 | const ast::ObjectDecl * returnDecl = nullptr; |
---|
| 650 | const CodeLocation loc = appExpr->location; |
---|
| 651 | |
---|
| 652 | // take each argument and attempt to copy construct it. |
---|
| 653 | auto ftype = GenPoly::getFunctionType( appExpr->func->result ); |
---|
| 654 | assert( ftype ); |
---|
| 655 | auto & params = ftype->params; |
---|
| 656 | auto iter = params.begin(); |
---|
| 657 | for ( auto & arg : appExpr->args ) { |
---|
| 658 | const ast::Type * formal = nullptr; |
---|
| 659 | if ( iter != params.end() ) { // does not copy construct C-style variadic arguments |
---|
| 660 | // DeclarationWithType * param = *iter++; |
---|
| 661 | formal = *iter++; |
---|
| 662 | } |
---|
[490fb92e] | 663 | |
---|
[0e707bd] | 664 | arg = copyConstructArg( arg, impCpCtorExpr, formal ); |
---|
| 665 | } // for |
---|
| 666 | |
---|
| 667 | // each return value from the call needs to be connected with an ObjectDecl at the call site, which is |
---|
| 668 | // initialized with the return value and is destructed later |
---|
| 669 | // xxx - handle named return values? |
---|
| 670 | const ast::Type * result = appExpr->result; |
---|
| 671 | if ( ! result->isVoid() ) { |
---|
| 672 | static UniqueName retNamer("_tmp_cp_ret"); |
---|
| 673 | auto subResult = env->apply( result ).node; |
---|
| 674 | auto ret = new ast::ObjectDecl(loc, retNamer.newName(), subResult, nullptr ); |
---|
| 675 | auto mutType = mutate(ret->type.get()); |
---|
| 676 | mutType->set_const( false ); |
---|
| 677 | ret->type = mutType; |
---|
| 678 | returnDecl = ret; |
---|
| 679 | stmtsToAddBefore.push_back( new ast::DeclStmt(loc, ret ) ); |
---|
| 680 | CP_CTOR_PRINT( std::cerr << "makeCtorDtor for a return" << std::endl; ) |
---|
| 681 | } // for |
---|
| 682 | CP_CTOR_PRINT( std::cerr << "after Resolving: " << impCpCtorExpr << std::endl; ) |
---|
| 683 | // ------------------------------------------------------ |
---|
| 684 | |
---|
| 685 | CP_CTOR_PRINT( std::cerr << "Coming out the back..." << impCpCtorExpr << std::endl; ) |
---|
| 686 | |
---|
| 687 | // detach fields from wrapper node so that it can be deleted without deleting too much |
---|
| 688 | |
---|
| 689 | // xxx - actual env might be somewhere else, need to keep invariant |
---|
| 690 | |
---|
| 691 | // deletion of wrapper should be handled by pass template now |
---|
| 692 | |
---|
| 693 | // impCpCtorExpr->callExpr = nullptr; |
---|
| 694 | assert (appExpr->env == nullptr); |
---|
| 695 | appExpr->env = impCpCtorExpr->env; |
---|
| 696 | // std::swap( impCpCtorExpr->env, appExpr->env ); |
---|
| 697 | // assert( impCpCtorExpr->env == nullptr ); |
---|
| 698 | // delete impCpCtorExpr; |
---|
| 699 | |
---|
| 700 | if ( returnDecl ) { |
---|
| 701 | ast::Expr * assign = createBitwiseAssignment( new ast::VariableExpr(loc, returnDecl ), appExpr ); |
---|
| 702 | if ( ! dynamic_cast< const ast::ReferenceType * >( result ) ) { |
---|
| 703 | // destructing reference returns is bad because it can cause multiple destructor calls to the same object - the returned object is not a temporary |
---|
| 704 | assign = destructRet( returnDecl, assign ); |
---|
| 705 | assert(assign); |
---|
[490fb92e] | 706 | } else { |
---|
[0e707bd] | 707 | assign = new ast::CommaExpr(loc, assign, new ast::VariableExpr(loc, returnDecl ) ); |
---|
| 708 | } |
---|
| 709 | // move env from appExpr to retExpr |
---|
| 710 | // std::swap( assign->env, appExpr->env ); |
---|
| 711 | assign->env = appExpr->env; |
---|
| 712 | // actual env is handled by common routine that replaces WithTypeSubstitution |
---|
| 713 | return postvisit((const ast::Expr *)assign); |
---|
| 714 | } else { |
---|
| 715 | return postvisit((const ast::Expr *)appExpr); |
---|
| 716 | } // if |
---|
| 717 | } |
---|
[490fb92e] | 718 | |
---|
[0e707bd] | 719 | const ast::StmtExpr * ResolveCopyCtors::previsit( const ast::StmtExpr * _stmtExpr ) { |
---|
| 720 | // function call temporaries should be placed at statement-level, rather than nested inside of a new statement expression, |
---|
| 721 | // since temporaries can be shared across sub-expressions, e.g. |
---|
| 722 | // [A, A] f(); // decl |
---|
| 723 | // g([A] x, [A] y); // decl |
---|
| 724 | // g(f()); // call |
---|
| 725 | // f is executed once, so the return temporary is shared across the tuple constructors for x and y. |
---|
| 726 | // Explicitly mutating children instead of mutating the inner compound statement forces the temporaries to be added |
---|
| 727 | // to the outer context, rather than inside of the statement expression. |
---|
| 728 | |
---|
| 729 | // call the common routine that replaces WithTypeSubstitution |
---|
| 730 | previsit((const ast::Expr *) _stmtExpr); |
---|
| 731 | |
---|
| 732 | visit_children = false; |
---|
| 733 | const CodeLocation loc = _stmtExpr->location; |
---|
| 734 | |
---|
| 735 | assert( env ); |
---|
| 736 | |
---|
| 737 | symtab.enterScope(); |
---|
| 738 | // visit all statements |
---|
| 739 | auto stmtExpr = mutate(_stmtExpr); |
---|
| 740 | auto mutStmts = mutate(stmtExpr->stmts.get()); |
---|
| 741 | |
---|
| 742 | auto & stmts = mutStmts->kids; |
---|
| 743 | for ( auto & stmt : stmts ) { |
---|
| 744 | stmt = stmt->accept( *visitor ); |
---|
| 745 | } // for |
---|
| 746 | stmtExpr->stmts = mutStmts; |
---|
| 747 | symtab.leaveScope(); |
---|
| 748 | |
---|
| 749 | assert( stmtExpr->result ); |
---|
| 750 | // const ast::Type * result = stmtExpr->result; |
---|
| 751 | if ( ! stmtExpr->result->isVoid() ) { |
---|
| 752 | static UniqueName retNamer("_tmp_stmtexpr_ret"); |
---|
| 753 | |
---|
| 754 | // result = result->clone(); |
---|
| 755 | auto result = env->apply( stmtExpr->result.get() ).node; |
---|
| 756 | if ( ! InitTweak::isConstructable( result ) ) { |
---|
| 757 | // delete result; |
---|
| 758 | return stmtExpr; |
---|
| 759 | } |
---|
| 760 | auto mutResult = result.get_and_mutate(); |
---|
| 761 | mutResult->set_const(false); |
---|
[490fb92e] | 762 | |
---|
[0e707bd] | 763 | // create variable that will hold the result of the stmt expr |
---|
| 764 | auto ret = new ast::ObjectDecl(loc, retNamer.newName(), mutResult, nullptr ); |
---|
| 765 | stmtsToAddBefore.push_back( new ast::DeclStmt(loc, ret ) ); |
---|
| 766 | |
---|
| 767 | assertf( |
---|
| 768 | stmtExpr->resultExpr, |
---|
| 769 | "Statement-Expression should have a resulting expression at %s:%d", |
---|
| 770 | stmtExpr->location.filename.c_str(), |
---|
| 771 | stmtExpr->location.first_line |
---|
| 772 | ); |
---|
| 773 | |
---|
| 774 | const ast::ExprStmt * last = stmtExpr->resultExpr; |
---|
| 775 | // xxx - if this is non-unique, need to copy while making resultExpr ref |
---|
| 776 | assertf(last->unique(), "attempt to modify weakly shared statement"); |
---|
| 777 | auto mutLast = mutate(last); |
---|
| 778 | // above assertion means in-place mutation is OK |
---|
| 779 | try { |
---|
| 780 | mutLast->expr = makeCtorDtor( "?{}", ret, mutLast->expr ); |
---|
| 781 | } catch(...) { |
---|
| 782 | std::cerr << "*CFA internal error: "; |
---|
| 783 | std::cerr << "can't resolve implicit constructor"; |
---|
| 784 | std::cerr << " at " << stmtExpr->location.filename; |
---|
| 785 | std::cerr << ":" << stmtExpr->location.first_line << std::endl; |
---|
| 786 | |
---|
| 787 | abort(); |
---|
| 788 | } |
---|
[490fb92e] | 789 | |
---|
[0e707bd] | 790 | // add destructors after current statement |
---|
| 791 | stmtsToAddAfter.push_back( new ast::ExprStmt(loc, makeCtorDtor( "^?{}", ret ) ) ); |
---|
[490fb92e] | 792 | |
---|
[0e707bd] | 793 | // must have a non-empty body, otherwise it wouldn't have a result |
---|
| 794 | assert( ! stmts.empty() ); |
---|
[490fb92e] | 795 | |
---|
[0e707bd] | 796 | // if there is a return decl, add a use as the last statement; will not have return decl on non-constructable returns |
---|
| 797 | stmts.push_back( new ast::ExprStmt(loc, new ast::VariableExpr(loc, ret ) ) ); |
---|
| 798 | } // if |
---|
[490fb92e] | 799 | |
---|
[0e707bd] | 800 | assert( stmtExpr->returnDecls.empty() ); |
---|
| 801 | assert( stmtExpr->dtors.empty() ); |
---|
[490fb92e] | 802 | |
---|
[0e707bd] | 803 | return stmtExpr; |
---|
| 804 | } |
---|
[490fb92e] | 805 | |
---|
[0e707bd] | 806 | // to prevent warnings ('_unq0' may be used uninitialized in this function), |
---|
| 807 | // insert an appropriate zero initializer for UniqueExpr temporaries. |
---|
[33b7d49] | 808 | ast::Init * makeInit( const ast::Type * t, CodeLocation const & loc ) { |
---|
[0e707bd] | 809 | if ( auto inst = dynamic_cast< const ast::StructInstType * >( t ) ) { |
---|
| 810 | // initizer for empty struct must be empty |
---|
[33b7d49] | 811 | if ( inst->base->members.empty() ) { |
---|
| 812 | return new ast::ListInit( loc, {} ); |
---|
| 813 | } |
---|
[0e707bd] | 814 | } else if ( auto inst = dynamic_cast< const ast::UnionInstType * >( t ) ) { |
---|
| 815 | // initizer for empty union must be empty |
---|
[33b7d49] | 816 | if ( inst->base->members.empty() ) { |
---|
| 817 | return new ast::ListInit( loc, {} ); |
---|
| 818 | } |
---|
[490fb92e] | 819 | } |
---|
| 820 | |
---|
[33b7d49] | 821 | return new ast::ListInit( loc, { |
---|
| 822 | new ast::SingleInit( loc, ast::ConstantExpr::from_int( loc, 0 ) ) |
---|
| 823 | } ); |
---|
[0e707bd] | 824 | } |
---|
[490fb92e] | 825 | |
---|
[0e707bd] | 826 | const ast::UniqueExpr * ResolveCopyCtors::previsit( const ast::UniqueExpr * unqExpr ) { |
---|
| 827 | visit_children = false; |
---|
| 828 | // xxx - hack to prevent double-handling of unique exprs, otherwise too many temporary variables and destructors are generated |
---|
| 829 | static std::unordered_map< int, const ast::UniqueExpr * > unqMap; |
---|
| 830 | auto mutExpr = mutate(unqExpr); |
---|
| 831 | if ( ! unqMap.count( unqExpr->id ) ) { |
---|
| 832 | // resolve expr and find its |
---|
| 833 | |
---|
| 834 | auto impCpCtorExpr = mutExpr->expr.as<ast::ImplicitCopyCtorExpr>(); |
---|
| 835 | // PassVisitor<ResolveCopyCtors> fixer; |
---|
| 836 | |
---|
| 837 | mutExpr->expr = mutExpr->expr->accept( *visitor ); |
---|
| 838 | // it should never be necessary to wrap a void-returning expression in a UniqueExpr - if this assumption changes, this needs to be rethought |
---|
| 839 | assert( unqExpr->result ); |
---|
| 840 | if ( impCpCtorExpr ) { |
---|
| 841 | auto comma = unqExpr->expr.strict_as<ast::CommaExpr>(); |
---|
| 842 | auto var = comma->arg2.strict_as<ast::VariableExpr>(); |
---|
| 843 | // note the variable used as the result from the call |
---|
| 844 | mutExpr->var = var; |
---|
[490fb92e] | 845 | } else { |
---|
[0e707bd] | 846 | // expr isn't a call expr, so create a new temporary variable to use to hold the value of the unique expression |
---|
[33b7d49] | 847 | mutExpr->object = new ast::ObjectDecl( mutExpr->location, toString("_unq", mutExpr->id), mutExpr->result, makeInit( mutExpr->result, mutExpr->location ) ); |
---|
[0e707bd] | 848 | mutExpr->var = new ast::VariableExpr( mutExpr->location, mutExpr->object ); |
---|
[490fb92e] | 849 | } |
---|
[0e707bd] | 850 | |
---|
| 851 | unqMap[mutExpr->id] = mutExpr; |
---|
| 852 | } else { |
---|
| 853 | // take data from other UniqueExpr to ensure consistency |
---|
| 854 | // delete unqExpr->get_expr(); |
---|
| 855 | mutExpr->expr = unqMap[mutExpr->id]->expr; |
---|
| 856 | // delete unqExpr->result; |
---|
| 857 | mutExpr->result = mutExpr->expr->result; |
---|
[490fb92e] | 858 | } |
---|
[0e707bd] | 859 | return mutExpr; |
---|
| 860 | } |
---|
[490fb92e] | 861 | |
---|
[0e707bd] | 862 | const ast::DeclWithType * FixInit::postvisit( const ast::ObjectDecl *_objDecl ) { |
---|
| 863 | const CodeLocation loc = _objDecl->location; |
---|
[490fb92e] | 864 | |
---|
[0e707bd] | 865 | // since this removes the init field from objDecl, it must occur after children are mutated (i.e. postvisit) |
---|
| 866 | if ( ast::ptr<ast::ConstructorInit> ctorInit = _objDecl->init.as<ast::ConstructorInit>() ) { |
---|
| 867 | auto objDecl = mutate(_objDecl); |
---|
[490fb92e] | 868 | |
---|
[0e707bd] | 869 | // could this be non-unique? |
---|
| 870 | if (objDecl != _objDecl) { |
---|
| 871 | std::cerr << "FixInit: non-unique object decl " << objDecl->location << objDecl->name << std::endl; |
---|
| 872 | } |
---|
| 873 | // a decision should have been made by the resolver, so ctor and init are not both non-NULL |
---|
| 874 | assert( ! ctorInit->ctor || ! ctorInit->init ); |
---|
| 875 | if ( const ast::Stmt * ctor = ctorInit->ctor ) { |
---|
| 876 | if ( objDecl->storage.is_static ) { |
---|
[7d651a6] | 877 | addDataSectionAttribute(objDecl); |
---|
[0e707bd] | 878 | // originally wanted to take advantage of gcc nested functions, but |
---|
| 879 | // we get memory errors with this approach. To remedy this, the static |
---|
| 880 | // variable is hoisted when the destructor needs to be called. |
---|
| 881 | // |
---|
| 882 | // generate: |
---|
| 883 | // static T __objName_static_varN; |
---|
| 884 | // void __objName_dtor_atexitN() { |
---|
| 885 | // __dtor__...; |
---|
| 886 | // } |
---|
| 887 | // int f(...) { |
---|
| 888 | // ... |
---|
| 889 | // static bool __objName_uninitialized = true; |
---|
| 890 | // if (__objName_uninitialized) { |
---|
| 891 | // __ctor(__objName); |
---|
| 892 | // __objName_uninitialized = false; |
---|
| 893 | // atexit(__objName_dtor_atexitN); |
---|
| 894 | // } |
---|
| 895 | // ... |
---|
| 896 | // } |
---|
| 897 | |
---|
| 898 | static UniqueName dtorCallerNamer( "_dtor_atexit" ); |
---|
| 899 | |
---|
| 900 | // static bool __objName_uninitialized = true |
---|
| 901 | auto boolType = new ast::BasicType( ast::BasicType::Kind::Bool ); |
---|
| 902 | auto boolInitExpr = new ast::SingleInit(loc, ast::ConstantExpr::from_int(loc, 1 ) ); |
---|
| 903 | auto isUninitializedVar = new ast::ObjectDecl(loc, objDecl->mangleName + "_uninitialized", boolType, boolInitExpr, ast::Storage::Static, ast::Linkage::Cforall); |
---|
| 904 | isUninitializedVar->fixUniqueId(); |
---|
| 905 | |
---|
| 906 | // __objName_uninitialized = false; |
---|
| 907 | auto setTrue = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "?=?" ) ); |
---|
| 908 | setTrue->args.push_back( new ast::VariableExpr(loc, isUninitializedVar ) ); |
---|
| 909 | setTrue->args.push_back( ast::ConstantExpr::from_int(loc, 0 ) ); |
---|
| 910 | |
---|
| 911 | // generate body of if |
---|
| 912 | auto initStmts = new ast::CompoundStmt(loc); |
---|
| 913 | auto & body = initStmts->kids; |
---|
| 914 | body.push_back( ctor ); |
---|
| 915 | body.push_back( new ast::ExprStmt(loc, setTrue ) ); |
---|
| 916 | |
---|
| 917 | // put it all together |
---|
| 918 | auto ifStmt = new ast::IfStmt(loc, new ast::VariableExpr(loc, isUninitializedVar ), initStmts, 0 ); |
---|
| 919 | stmtsToAddAfter.push_back( new ast::DeclStmt(loc, isUninitializedVar ) ); |
---|
| 920 | stmtsToAddAfter.push_back( ifStmt ); |
---|
| 921 | |
---|
| 922 | const ast::Stmt * dtor = ctorInit->dtor; |
---|
| 923 | |
---|
| 924 | // these should be automatically managed once reassigned |
---|
| 925 | // objDecl->set_init( nullptr ); |
---|
| 926 | // ctorInit->set_ctor( nullptr ); |
---|
| 927 | // ctorInit->set_dtor( nullptr ); |
---|
| 928 | if ( dtor ) { |
---|
| 929 | // if the object has a non-trivial destructor, have to |
---|
| 930 | // hoist it and the object into the global space and |
---|
| 931 | // call the destructor function with atexit. |
---|
| 932 | |
---|
| 933 | // Statement * dtorStmt = dtor->clone(); |
---|
| 934 | |
---|
| 935 | // void __objName_dtor_atexitN(...) {...} |
---|
| 936 | ast::FunctionDecl * dtorCaller = new ast::FunctionDecl(loc, objDecl->mangleName + dtorCallerNamer.newName(), {}, {}, {}, new ast::CompoundStmt(loc, {dtor}), ast::Storage::Static, ast::Linkage::C ); |
---|
| 937 | dtorCaller->fixUniqueId(); |
---|
| 938 | // dtorCaller->stmts->push_back( dtor ); |
---|
| 939 | |
---|
| 940 | // atexit(dtor_atexit); |
---|
| 941 | auto callAtexit = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "atexit" ) ); |
---|
| 942 | callAtexit->args.push_back( new ast::VariableExpr(loc, dtorCaller ) ); |
---|
| 943 | |
---|
| 944 | body.push_back( new ast::ExprStmt(loc, callAtexit ) ); |
---|
| 945 | |
---|
| 946 | // hoist variable and dtor caller decls to list of decls that will be added into global scope |
---|
| 947 | staticDtorDecls.push_back( objDecl ); |
---|
| 948 | staticDtorDecls.push_back( dtorCaller ); |
---|
| 949 | |
---|
| 950 | // need to rename object uniquely since it now appears |
---|
| 951 | // at global scope and there could be multiple function-scoped |
---|
| 952 | // static variables with the same name in different functions. |
---|
| 953 | // Note: it isn't sufficient to modify only the mangleName, because |
---|
| 954 | // then subsequent Indexer passes can choke on seeing the object's name |
---|
| 955 | // if another object has the same name and type. An unfortunate side-effect |
---|
| 956 | // of renaming the object is that subsequent NameExprs may fail to resolve, |
---|
| 957 | // but there shouldn't be any remaining past this point. |
---|
| 958 | static UniqueName staticNamer( "_static_var" ); |
---|
| 959 | objDecl->name = objDecl->name + staticNamer.newName(); |
---|
| 960 | objDecl->mangleName = Mangle::mangle( objDecl ); |
---|
[7d651a6] | 961 | objDecl->init = nullptr; |
---|
[0e707bd] | 962 | |
---|
| 963 | // xxx - temporary hack: need to return a declaration, but want to hoist the current object out of this scope |
---|
| 964 | // create a new object which is never used |
---|
| 965 | static UniqueName dummyNamer( "_dummy" ); |
---|
| 966 | auto dummy = new ast::ObjectDecl(loc, dummyNamer.newName(), new ast::PointerType(new ast::VoidType()), nullptr, ast::Storage::Static, ast::Linkage::Cforall, 0, { new ast::Attribute("unused") } ); |
---|
| 967 | // delete ctorInit; |
---|
| 968 | return dummy; |
---|
[490fb92e] | 969 | } else { |
---|
[0e707bd] | 970 | objDecl->init = nullptr; |
---|
| 971 | return objDecl; |
---|
| 972 | } |
---|
[490fb92e] | 973 | } else { |
---|
[0e707bd] | 974 | auto implicit = strict_dynamic_cast< const ast::ImplicitCtorDtorStmt * > ( ctor ); |
---|
| 975 | auto ctorStmt = implicit->callStmt.as<ast::ExprStmt>(); |
---|
| 976 | const ast::ApplicationExpr * ctorCall = nullptr; |
---|
| 977 | if ( ctorStmt && (ctorCall = isIntrinsicCallExpr( ctorStmt->expr )) && ctorCall->args.size() == 2 ) { |
---|
| 978 | // clean up intrinsic copy constructor calls by making them into SingleInits |
---|
| 979 | const ast::Expr * ctorArg = ctorCall->args.back(); |
---|
| 980 | // ctorCall should be gone afterwards |
---|
| 981 | auto mutArg = mutate(ctorArg); |
---|
| 982 | mutArg->env = ctorCall->env; |
---|
| 983 | // std::swap( ctorArg->env, ctorCall->env ); |
---|
| 984 | objDecl->init = new ast::SingleInit(loc, mutArg ); |
---|
| 985 | |
---|
| 986 | // ctorCall->args.pop_back(); |
---|
| 987 | } else { |
---|
| 988 | stmtsToAddAfter.push_back( ctor ); |
---|
| 989 | objDecl->init = nullptr; |
---|
| 990 | // ctorInit->ctor = nullptr; |
---|
| 991 | } |
---|
[490fb92e] | 992 | |
---|
[0e707bd] | 993 | const ast::Stmt * dtor = ctorInit->dtor; |
---|
| 994 | if ( dtor ) { |
---|
| 995 | auto implicit = strict_dynamic_cast< const ast::ImplicitCtorDtorStmt * >( dtor ); |
---|
| 996 | const ast::Stmt * dtorStmt = implicit->callStmt; |
---|
| 997 | |
---|
| 998 | // don't need to call intrinsic dtor, because it does nothing, but |
---|
| 999 | // non-intrinsic dtors must be called |
---|
| 1000 | if ( ! isIntrinsicSingleArgCallStmt( dtorStmt ) ) { |
---|
| 1001 | // set dtor location to the object's location for error messages |
---|
| 1002 | auto dtorFunc = getDtorFunc( objDecl, dtorStmt, stmtsToAddBefore ); |
---|
| 1003 | objDecl->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr(loc, dtorFunc ) } ) ); |
---|
| 1004 | // ctorInit->dtor = nullptr; |
---|
| 1005 | } // if |
---|
| 1006 | } |
---|
| 1007 | } // if |
---|
| 1008 | } else if ( const ast::Init * init = ctorInit->init ) { |
---|
| 1009 | objDecl->init = init; |
---|
| 1010 | // ctorInit->init = nullptr; |
---|
| 1011 | } else { |
---|
| 1012 | // no constructor and no initializer, which is okay |
---|
| 1013 | objDecl->init = nullptr; |
---|
[490fb92e] | 1014 | } // if |
---|
[0e707bd] | 1015 | // delete ctorInit; |
---|
| 1016 | return objDecl; |
---|
| 1017 | } // if |
---|
| 1018 | return _objDecl; |
---|
| 1019 | } |
---|
[490fb92e] | 1020 | |
---|
[0e707bd] | 1021 | void ObjDeclCollector::previsit( const ast::CompoundStmt * ) { |
---|
| 1022 | GuardValue( curVars ); |
---|
| 1023 | } |
---|
[490fb92e] | 1024 | |
---|
[0e707bd] | 1025 | void ObjDeclCollector::previsit( const ast::DeclStmt * stmt ) { |
---|
| 1026 | // keep track of all variables currently in scope |
---|
| 1027 | if ( auto objDecl = stmt->decl.as<ast::ObjectDecl>() ) { |
---|
| 1028 | curVars.push_back( objDecl ); |
---|
| 1029 | } // if |
---|
| 1030 | } |
---|
[490fb92e] | 1031 | |
---|
[0e707bd] | 1032 | void LabelFinder::previsit( const ast::Stmt * stmt ) { |
---|
| 1033 | // for each label, remember the variables in scope at that label. |
---|
| 1034 | for ( auto l : stmt->labels ) { |
---|
| 1035 | vars[l] = curVars; |
---|
| 1036 | } // for |
---|
| 1037 | } |
---|
[490fb92e] | 1038 | |
---|
[0e707bd] | 1039 | void LabelFinder::previsit( const ast::CompoundStmt * stmt ) { |
---|
| 1040 | previsit( (const ast::Stmt *) stmt ); |
---|
| 1041 | Parent::previsit( stmt ); |
---|
| 1042 | } |
---|
[490fb92e] | 1043 | |
---|
[0e707bd] | 1044 | void LabelFinder::previsit( const ast::DeclStmt * stmt ) { |
---|
| 1045 | previsit( (const ast::Stmt *)stmt ); |
---|
| 1046 | Parent::previsit( stmt ); |
---|
| 1047 | } |
---|
[490fb92e] | 1048 | |
---|
| 1049 | |
---|
[0e707bd] | 1050 | void InsertDtors::previsit( const ast::FunctionDecl * funcDecl ) { |
---|
| 1051 | // each function needs to have its own set of labels |
---|
| 1052 | GuardValue( labelVars ); |
---|
| 1053 | labelVars.clear(); |
---|
| 1054 | // LabelFinder does not recurse into FunctionDecl, so need to visit |
---|
| 1055 | // its children manually. |
---|
| 1056 | if (funcDecl->type) funcDecl->type->accept(finder); |
---|
| 1057 | // maybeAccept( funcDecl->type, finder ); |
---|
| 1058 | if (funcDecl->stmts) funcDecl->stmts->accept(finder) ; |
---|
[490fb92e] | 1059 | |
---|
[0e707bd] | 1060 | // all labels for this function have been collected, insert destructors as appropriate via implicit recursion. |
---|
| 1061 | } |
---|
[490fb92e] | 1062 | |
---|
[0e707bd] | 1063 | // Handle break/continue/goto in the same manner as C++. Basic idea: any objects that are in scope at the |
---|
| 1064 | // BranchStmt but not at the labelled (target) statement must be destructed. If there are any objects in scope |
---|
| 1065 | // at the target location but not at the BranchStmt then those objects would be uninitialized so notify the user |
---|
| 1066 | // of the error. See C++ Reference 6.6 Jump Statements for details. |
---|
| 1067 | void InsertDtors::handleGoto( const ast::BranchStmt * stmt ) { |
---|
| 1068 | // can't do anything for computed goto |
---|
| 1069 | if ( stmt->computedTarget ) return; |
---|
| 1070 | |
---|
| 1071 | assertf( stmt->target.name != "", "BranchStmt missing a label: %s", toString( stmt ).c_str() ); |
---|
| 1072 | // S_L = lvars = set of objects in scope at label definition |
---|
| 1073 | // S_G = curVars = set of objects in scope at goto statement |
---|
| 1074 | ObjectSet & lvars = labelVars[ stmt->target ]; |
---|
| 1075 | |
---|
| 1076 | DTOR_PRINT( |
---|
| 1077 | std::cerr << "at goto label: " << stmt->target.name << std::endl; |
---|
| 1078 | std::cerr << "S_G = " << printSet( curVars ) << std::endl; |
---|
| 1079 | std::cerr << "S_L = " << printSet( lvars ) << std::endl; |
---|
| 1080 | ) |
---|
| 1081 | |
---|
| 1082 | |
---|
| 1083 | // std::set_difference requires that the inputs be sorted. |
---|
| 1084 | lvars.sort(); |
---|
| 1085 | curVars.sort(); |
---|
| 1086 | |
---|
| 1087 | ObjectSet diff; |
---|
| 1088 | // S_L-S_G results in set of objects whose construction is skipped - it's an error if this set is non-empty |
---|
| 1089 | std::set_difference( lvars.begin(), lvars.end(), curVars.begin(), curVars.end(), std::inserter( diff, diff.begin() ) ); |
---|
| 1090 | DTOR_PRINT( |
---|
| 1091 | std::cerr << "S_L-S_G = " << printSet( diff ) << std::endl; |
---|
| 1092 | ) |
---|
| 1093 | if ( ! diff.empty() ) { |
---|
| 1094 | SemanticError( stmt, std::string("jump to label '") + stmt->target.name + "' crosses initialization of " + (*diff.begin())->name + " " ); |
---|
| 1095 | } // if |
---|
| 1096 | } |
---|
[490fb92e] | 1097 | |
---|
[0e707bd] | 1098 | void InsertDtors::previsit( const ast::BranchStmt * stmt ) { |
---|
| 1099 | switch( stmt->kind ) { |
---|
[fb4dc28] | 1100 | case ast::BranchStmt::Continue: |
---|
| 1101 | case ast::BranchStmt::Break: |
---|
[0e707bd] | 1102 | // could optimize the break/continue case, because the S_L-S_G check is unnecessary (this set should |
---|
| 1103 | // always be empty), but it serves as a small sanity check. |
---|
[fb4dc28] | 1104 | case ast::BranchStmt::Goto: |
---|
[0e707bd] | 1105 | handleGoto( stmt ); |
---|
| 1106 | break; |
---|
[fb4dc28] | 1107 | default: |
---|
[0e707bd] | 1108 | assert( false ); |
---|
| 1109 | } // switch |
---|
| 1110 | } |
---|
[490fb92e] | 1111 | |
---|
[0e707bd] | 1112 | bool checkWarnings( const ast::FunctionDecl * funcDecl ) { |
---|
| 1113 | // only check for warnings if the current function is a user-defined |
---|
| 1114 | // constructor or destructor |
---|
| 1115 | if ( ! funcDecl ) return false; |
---|
| 1116 | if ( ! funcDecl->stmts ) return false; |
---|
| 1117 | return CodeGen::isCtorDtor( funcDecl->name ) && ! funcDecl->linkage.is_overrideable; |
---|
| 1118 | } |
---|
[490fb92e] | 1119 | |
---|
[0e707bd] | 1120 | void GenStructMemberCalls::previsit( const ast::FunctionDecl * funcDecl ) { |
---|
| 1121 | GuardValue( function ); |
---|
| 1122 | GuardValue( unhandled ); |
---|
| 1123 | GuardValue( usedUninit ); |
---|
| 1124 | GuardValue( thisParam ); |
---|
| 1125 | GuardValue( isCtor ); |
---|
| 1126 | GuardValue( structDecl ); |
---|
| 1127 | errors = SemanticErrorException(); // clear previous errors |
---|
| 1128 | |
---|
| 1129 | // need to start with fresh sets |
---|
| 1130 | unhandled.clear(); |
---|
| 1131 | usedUninit.clear(); |
---|
| 1132 | |
---|
| 1133 | function = mutate(funcDecl); |
---|
| 1134 | // could this be non-unique? |
---|
| 1135 | if (function != funcDecl) { |
---|
| 1136 | std::cerr << "GenStructMemberCalls: non-unique FunctionDecl " << funcDecl->location << funcDecl->name << std::endl; |
---|
| 1137 | } |
---|
[490fb92e] | 1138 | |
---|
[0e707bd] | 1139 | isCtor = CodeGen::isConstructor( function->name ); |
---|
| 1140 | if ( checkWarnings( function ) ) { |
---|
| 1141 | // const ast::FunctionType * type = function->type; |
---|
| 1142 | // assert( ! type->params.empty() ); |
---|
| 1143 | thisParam = function->params.front().strict_as<ast::ObjectDecl>(); |
---|
| 1144 | auto thisType = getPointerBase( thisParam->get_type() ); |
---|
| 1145 | auto structType = dynamic_cast< const ast::StructInstType * >( thisType ); |
---|
| 1146 | if ( structType ) { |
---|
| 1147 | structDecl = structType->base; |
---|
| 1148 | for ( auto & member : structDecl->members ) { |
---|
| 1149 | if ( auto field = member.as<ast::ObjectDecl>() ) { |
---|
| 1150 | // record all of the struct type's members that need to be constructed or |
---|
| 1151 | // destructed by the end of the function |
---|
| 1152 | unhandled.insert( field ); |
---|
[490fb92e] | 1153 | } |
---|
| 1154 | } |
---|
| 1155 | } |
---|
| 1156 | } |
---|
[0e707bd] | 1157 | } |
---|
[490fb92e] | 1158 | |
---|
[0e707bd] | 1159 | const ast::DeclWithType * GenStructMemberCalls::postvisit( const ast::FunctionDecl * funcDecl ) { |
---|
| 1160 | // remove the unhandled objects from usedUninit, because a call is inserted |
---|
| 1161 | // to handle them - only objects that are later constructed are used uninitialized. |
---|
| 1162 | std::map< const ast::DeclWithType *, CodeLocation > diff; |
---|
| 1163 | // need the comparator since usedUninit and unhandled have different types |
---|
| 1164 | struct comp_t { |
---|
| 1165 | typedef decltype(usedUninit)::value_type usedUninit_t; |
---|
| 1166 | typedef decltype(unhandled)::value_type unhandled_t; |
---|
| 1167 | bool operator()(usedUninit_t x, unhandled_t y) { return x.first < y; } |
---|
| 1168 | bool operator()(unhandled_t x, usedUninit_t y) { return x < y.first; } |
---|
| 1169 | } comp; |
---|
| 1170 | std::set_difference( usedUninit.begin(), usedUninit.end(), unhandled.begin(), unhandled.end(), std::inserter( diff, diff.begin() ), comp ); |
---|
| 1171 | for ( auto p : diff ) { |
---|
| 1172 | auto member = p.first; |
---|
| 1173 | auto loc = p.second; |
---|
| 1174 | // xxx - make error message better by also tracking the location that the object is constructed at? |
---|
| 1175 | emit( loc, "in ", function->name, ", field ", member->name, " used before being constructed" ); |
---|
| 1176 | } |
---|
[490fb92e] | 1177 | |
---|
[0e707bd] | 1178 | const CodeLocation loc = funcDecl->location; |
---|
| 1179 | |
---|
| 1180 | if ( ! unhandled.empty() ) { |
---|
| 1181 | auto mutStmts = function->stmts.get_and_mutate(); |
---|
| 1182 | // need to explicitly re-add function parameters to the indexer in order to resolve copy constructors |
---|
| 1183 | auto guard = makeFuncGuard( [this]() { symtab.enterScope(); }, [this]() { symtab.leaveScope(); } ); |
---|
| 1184 | symtab.addFunction( function ); |
---|
[39d8950] | 1185 | auto global = transUnit().global; |
---|
[0e707bd] | 1186 | |
---|
| 1187 | // need to iterate through members in reverse in order for |
---|
| 1188 | // ctor/dtor statements to come out in the right order |
---|
| 1189 | for ( auto & member : reverseIterate( structDecl->members ) ) { |
---|
| 1190 | auto field = member.as<ast::ObjectDecl>(); |
---|
| 1191 | // skip non-DWT members |
---|
| 1192 | if ( ! field ) continue; |
---|
| 1193 | // skip non-constructable members |
---|
| 1194 | if ( ! tryConstruct( field ) ) continue; |
---|
| 1195 | // skip handled members |
---|
| 1196 | if ( ! unhandled.count( field ) ) continue; |
---|
| 1197 | |
---|
| 1198 | // insert and resolve default/copy constructor call for each field that's unhandled |
---|
| 1199 | // std::list< const ast::Stmt * > stmt; |
---|
| 1200 | ast::Expr * arg2 = nullptr; |
---|
| 1201 | if ( function->name == "?{}" && isCopyFunction( function ) ) { |
---|
| 1202 | // if copy ctor, need to pass second-param-of-this-function.field |
---|
| 1203 | // std::list< DeclarationWithType * > & params = function->get_functionType()->get_parameters(); |
---|
| 1204 | assert( function->params.size() == 2 ); |
---|
| 1205 | arg2 = new ast::MemberExpr(funcDecl->location, field, new ast::VariableExpr(funcDecl->location, function->params.back() ) ); |
---|
| 1206 | } |
---|
| 1207 | InitExpander_new srcParam( arg2 ); |
---|
| 1208 | // cast away reference type and construct field. |
---|
| 1209 | ast::Expr * thisExpr = new ast::CastExpr(funcDecl->location, new ast::VariableExpr(funcDecl->location, thisParam ), thisParam->get_type()->stripReferences()); |
---|
| 1210 | ast::Expr * memberDest = new ast::MemberExpr(funcDecl->location, field, thisExpr ); |
---|
| 1211 | ast::ptr<ast::Stmt> callStmt = SymTab::genImplicitCall( srcParam, memberDest, loc, function->name, field, static_cast<SymTab::LoopDirection>(isCtor) ); |
---|
| 1212 | |
---|
| 1213 | if ( callStmt ) { |
---|
| 1214 | // auto & callStmt = stmt.front(); |
---|
| 1215 | |
---|
| 1216 | try { |
---|
| 1217 | callStmt = callStmt->accept( *visitor ); |
---|
| 1218 | if ( isCtor ) { |
---|
| 1219 | mutStmts->push_front( callStmt ); |
---|
| 1220 | } else { // TODO: don't generate destructor function/object for intrinsic calls |
---|
| 1221 | // destructor statements should be added at the end |
---|
| 1222 | // function->get_statements()->push_back( callStmt ); |
---|
| 1223 | |
---|
| 1224 | // Optimization: do not need to call intrinsic destructors on members |
---|
| 1225 | if ( isIntrinsicSingleArgCallStmt( callStmt ) ) continue; |
---|
| 1226 | |
---|
| 1227 | // __Destructor _dtor0 = { (void *)&b.a1, (void (*)(void *)_destroy_A }; |
---|
| 1228 | std::list< ast::ptr<ast::Stmt> > stmtsToAdd; |
---|
| 1229 | |
---|
| 1230 | static UniqueName memberDtorNamer = { "__memberDtor" }; |
---|
[39d8950] | 1231 | assertf( global.dtorStruct, "builtin __Destructor not found." ); |
---|
| 1232 | assertf( global.dtorDestroy, "builtin __destroy_Destructor not found." ); |
---|
[0e707bd] | 1233 | |
---|
| 1234 | ast::Expr * thisExpr = new ast::CastExpr( new ast::AddressExpr( new ast::VariableExpr(loc, thisParam ) ), new ast::PointerType( new ast::VoidType(), ast::CV::Qualifiers() ) ); |
---|
| 1235 | ast::Expr * dtorExpr = new ast::VariableExpr(loc, getDtorFunc( thisParam, callStmt, stmtsToAdd ) ); |
---|
| 1236 | |
---|
| 1237 | // cast destructor pointer to void (*)(void *), to silence GCC incompatible pointer warnings |
---|
| 1238 | auto dtorFtype = new ast::FunctionType(); |
---|
| 1239 | dtorFtype->params.emplace_back( new ast::PointerType( new ast::VoidType() ) ); |
---|
| 1240 | auto dtorType = new ast::PointerType( dtorFtype ); |
---|
| 1241 | |
---|
[39d8950] | 1242 | auto destructor = new ast::ObjectDecl(loc, memberDtorNamer.newName(), new ast::StructInstType( global.dtorStruct ), new ast::ListInit(loc, { new ast::SingleInit(loc, thisExpr ), new ast::SingleInit(loc, new ast::CastExpr( dtorExpr, dtorType ) ) } ) ); |
---|
| 1243 | destructor->attributes.push_back( new ast::Attribute( "cleanup", { new ast::VariableExpr( loc, global.dtorDestroy ) } ) ); |
---|
[0e707bd] | 1244 | mutStmts->push_front( new ast::DeclStmt(loc, destructor ) ); |
---|
| 1245 | mutStmts->kids.splice( mutStmts->kids.begin(), stmtsToAdd ); |
---|
[490fb92e] | 1246 | } |
---|
[0e707bd] | 1247 | } catch ( SemanticErrorException & error ) { |
---|
| 1248 | emit( funcDecl->location, "in ", function->name , ", field ", field->name, " not explicitly ", isCtor ? "constructed" : "destructed", " and no ", isCtor ? "default constructor" : "destructor", " found" ); |
---|
[490fb92e] | 1249 | } |
---|
| 1250 | } |
---|
| 1251 | } |
---|
[0e707bd] | 1252 | function->stmts = mutStmts; |
---|
[490fb92e] | 1253 | } |
---|
[0e707bd] | 1254 | if (! errors.isEmpty()) { |
---|
| 1255 | throw errors; |
---|
[490fb92e] | 1256 | } |
---|
[0e707bd] | 1257 | // return funcDecl; |
---|
| 1258 | return function; |
---|
| 1259 | } |
---|
[490fb92e] | 1260 | |
---|
[0e707bd] | 1261 | /// true if expr is effectively just the 'this' parameter |
---|
| 1262 | bool isThisExpression( const ast::Expr * expr, const ast::DeclWithType * thisParam ) { |
---|
| 1263 | // TODO: there are more complicated ways to pass 'this' to a constructor, e.g. &*, *&, etc. |
---|
| 1264 | if ( auto varExpr = dynamic_cast< const ast::VariableExpr * >( expr ) ) { |
---|
| 1265 | return varExpr->var == thisParam; |
---|
| 1266 | } else if ( auto castExpr = dynamic_cast< const ast::CastExpr * > ( expr ) ) { |
---|
| 1267 | return isThisExpression( castExpr->arg, thisParam ); |
---|
[490fb92e] | 1268 | } |
---|
[0e707bd] | 1269 | return false; |
---|
| 1270 | } |
---|
[490fb92e] | 1271 | |
---|
[0e707bd] | 1272 | /// returns a MemberExpr if expr is effectively just member access on the 'this' parameter, else nullptr |
---|
| 1273 | const ast::MemberExpr * isThisMemberExpr( const ast::Expr * expr, const ast::DeclWithType * thisParam ) { |
---|
| 1274 | if ( auto memberExpr = dynamic_cast< const ast::MemberExpr * >( expr ) ) { |
---|
| 1275 | if ( isThisExpression( memberExpr->aggregate, thisParam ) ) { |
---|
| 1276 | return memberExpr; |
---|
[490fb92e] | 1277 | } |
---|
[0e707bd] | 1278 | } else if ( auto castExpr = dynamic_cast< const ast::CastExpr * >( expr ) ) { |
---|
| 1279 | return isThisMemberExpr( castExpr->arg, thisParam ); |
---|
[490fb92e] | 1280 | } |
---|
[0e707bd] | 1281 | return nullptr; |
---|
| 1282 | } |
---|
[490fb92e] | 1283 | |
---|
[0e707bd] | 1284 | void GenStructMemberCalls::previsit( const ast::ApplicationExpr * appExpr ) { |
---|
| 1285 | if ( ! checkWarnings( function ) ) { |
---|
| 1286 | visit_children = false; |
---|
| 1287 | return; |
---|
| 1288 | } |
---|
[490fb92e] | 1289 | |
---|
[0e707bd] | 1290 | std::string fname = getFunctionName( appExpr ); |
---|
| 1291 | if ( fname == function->name ) { |
---|
| 1292 | // call to same kind of function |
---|
| 1293 | const ast::Expr * firstParam = appExpr->args.front(); |
---|
| 1294 | |
---|
| 1295 | if ( isThisExpression( firstParam, thisParam ) ) { |
---|
| 1296 | // if calling another constructor on thisParam, assume that function handles |
---|
| 1297 | // all members - if it doesn't a warning will appear in that function. |
---|
| 1298 | unhandled.clear(); |
---|
| 1299 | } else if ( auto memberExpr = isThisMemberExpr( firstParam, thisParam ) ) { |
---|
| 1300 | // if first parameter is a member expression on the this parameter, |
---|
| 1301 | // then remove the member from unhandled set. |
---|
| 1302 | if ( isThisExpression( memberExpr->aggregate, thisParam ) ) { |
---|
| 1303 | unhandled.erase( memberExpr->member ); |
---|
[490fb92e] | 1304 | } |
---|
| 1305 | } |
---|
| 1306 | } |
---|
[0e707bd] | 1307 | } |
---|
[490fb92e] | 1308 | |
---|
[0e707bd] | 1309 | void GenStructMemberCalls::previsit( const ast::MemberExpr * memberExpr ) { |
---|
| 1310 | if ( ! checkWarnings( function ) || ! isCtor ) { |
---|
| 1311 | visit_children = false; |
---|
| 1312 | return; |
---|
[490fb92e] | 1313 | } |
---|
| 1314 | |
---|
[0e707bd] | 1315 | if ( isThisExpression( memberExpr->aggregate, thisParam ) ) { |
---|
| 1316 | if ( unhandled.count( memberExpr->member ) ) { |
---|
| 1317 | // emit a warning because a member was used before it was constructed |
---|
| 1318 | usedUninit.insert( { memberExpr->member, memberExpr->location } ); |
---|
| 1319 | } |
---|
[490fb92e] | 1320 | } |
---|
[0e707bd] | 1321 | } |
---|
[490fb92e] | 1322 | |
---|
[0e707bd] | 1323 | template< typename... Params > |
---|
| 1324 | void GenStructMemberCalls::emit( CodeLocation loc, const Params &... params ) { |
---|
[c94b1f0] | 1325 | SemanticErrorException err( loc, toString( params... ) ); |
---|
| 1326 | errors.append( err ); |
---|
[0e707bd] | 1327 | } |
---|
[490fb92e] | 1328 | |
---|
[0e707bd] | 1329 | const ast::Expr * GenStructMemberCalls::postvisit( const ast::UntypedExpr * untypedExpr ) { |
---|
| 1330 | // xxx - functions returning ast::ptr seems wrong... |
---|
[39d8950] | 1331 | auto res = ResolvExpr::findVoidExpression( untypedExpr, { symtab, transUnit().global } ); |
---|
[eb8d791] | 1332 | return res.release(); |
---|
[0e707bd] | 1333 | } |
---|
[490fb92e] | 1334 | |
---|
[0e707bd] | 1335 | void InsertImplicitCalls::previsit(const ast::UniqueExpr * unqExpr) { |
---|
| 1336 | if (visitedIds.count(unqExpr->id)) visit_children = false; |
---|
| 1337 | else visitedIds.insert(unqExpr->id); |
---|
| 1338 | } |
---|
| 1339 | |
---|
| 1340 | const ast::Expr * FixCtorExprs::postvisit( const ast::ConstructorExpr * ctorExpr ) { |
---|
| 1341 | const CodeLocation loc = ctorExpr->location; |
---|
| 1342 | static UniqueName tempNamer( "_tmp_ctor_expr" ); |
---|
| 1343 | // xxx - is the size check necessary? |
---|
| 1344 | assert( ctorExpr->result && ctorExpr->result->size() == 1 ); |
---|
| 1345 | |
---|
| 1346 | // xxx - this can be TupleAssignExpr now. Need to properly handle this case. |
---|
| 1347 | // take possession of expr and env |
---|
| 1348 | ast::ptr<ast::ApplicationExpr> callExpr = ctorExpr->callExpr.strict_as<ast::ApplicationExpr>(); |
---|
| 1349 | ast::ptr<ast::TypeSubstitution> env = ctorExpr->env; |
---|
| 1350 | // ctorExpr->set_callExpr( nullptr ); |
---|
| 1351 | // ctorExpr->set_env( nullptr ); |
---|
| 1352 | |
---|
| 1353 | // 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. |
---|
| 1354 | auto tmp = new ast::ObjectDecl(loc, tempNamer.newName(), callExpr->args.front()->result ); |
---|
| 1355 | declsToAddBefore.push_back( tmp ); |
---|
| 1356 | |
---|
| 1357 | // build assignment and replace constructor's first argument with new temporary |
---|
| 1358 | auto mutCallExpr = callExpr.get_and_mutate(); |
---|
| 1359 | const ast::Expr * firstArg = callExpr->args.front(); |
---|
| 1360 | ast::Expr * assign = new ast::UntypedExpr(loc, new ast::NameExpr(loc, "?=?" ), { new ast::AddressExpr(loc, new ast::VariableExpr(loc, tmp ) ), new ast::AddressExpr( firstArg ) } ); |
---|
| 1361 | firstArg = new ast::VariableExpr(loc, tmp ); |
---|
| 1362 | mutCallExpr->args.front() = firstArg; |
---|
| 1363 | |
---|
| 1364 | // resolve assignment and dispose of new env |
---|
[39d8950] | 1365 | auto resolved = ResolvExpr::findVoidExpression( assign, { symtab, transUnit().global } ); |
---|
[0e707bd] | 1366 | auto mut = resolved.get_and_mutate(); |
---|
| 1367 | assertf(resolved.get() == mut, "newly resolved expression must be unique"); |
---|
| 1368 | mut->env = nullptr; |
---|
| 1369 | |
---|
| 1370 | // for constructor expr: |
---|
| 1371 | // T x; |
---|
| 1372 | // x{}; |
---|
| 1373 | // results in: |
---|
| 1374 | // T x; |
---|
| 1375 | // T & tmp; |
---|
| 1376 | // &tmp = &x, ?{}(tmp), tmp |
---|
| 1377 | ast::CommaExpr * commaExpr = new ast::CommaExpr(loc, resolved, new ast::CommaExpr(loc, mutCallExpr, new ast::VariableExpr(loc, tmp ) ) ); |
---|
| 1378 | commaExpr->env = env; |
---|
| 1379 | return commaExpr; |
---|
| 1380 | } |
---|
| 1381 | } // namespace |
---|
[490fb92e] | 1382 | } // namespace InitTweak |
---|
| 1383 | |
---|
| 1384 | // Local Variables: // |
---|
| 1385 | // tab-width: 4 // |
---|
| 1386 | // mode: c++ // |
---|
| 1387 | // compile-command: "make install" // |
---|
| 1388 | // End: // |
---|