Changes in src/ResolvExpr/Resolver.cc [d76c588:99d4584]

File:

• src/ResolvExpr/Resolver.cc (modified) (35 diffs)

src/ResolvExpr/Resolver.cc

@@ -21 +21 @@
 #include "Alternative.h"                 // for Alternative, AltList
 #include "AlternativeFinder.h"           // for AlternativeFinder, resolveIn...
+#include "Candidate.hpp"
+#include "CandidateFinder.hpp"
 #include "CurrentObject.h"               // for CurrentObject
 #include "RenameVars.h"                  // for RenameVars, global_renamer
@@ -27 +29 @@
 #include "typeops.h"                     // for extractResultType
 #include "Unify.h"                       // for unify
+#include "AST/Decl.hpp"
+#include "AST/Init.hpp"
 #include "AST/Pass.hpp"
+#include "AST/Print.hpp"
 #include "AST/SymbolTable.hpp"
 #include "Common/PassVisitor.h"          // for PassVisitor
@@ -45 +50 @@
 #include "SynTree/Visitor.h"             // for acceptAll, maybeAccept
 #include "Tuples/Tuples.h"
+#include "Validate/FindSpecialDecls.h"   // for SizeType
 
 using namespace std;
@@ -112 +118 @@
 
         namespace {
-                struct DeleteFinder : public WithShortCircuiting        {
+                struct DeleteFinder_old : public WithShortCircuiting    {
                         DeletedExpr * delExpr = nullptr;
                         void previsit( DeletedExpr * expr ) {
@@ -126 +132 @@
 
         DeletedExpr * findDeletedExpr( Expression * expr ) {
-                PassVisitor<DeleteFinder> finder;
+                PassVisitor<DeleteFinder_old> finder;
                 expr->accept( finder );
                 return finder.pass.delExpr;
@@ -132 +138 @@
 
         namespace {
-                struct StripCasts {
+                struct StripCasts_old {
                         Expression * postmutate( CastExpr * castExpr ) {
                                 if ( castExpr->isGenerated && ResolvExpr::typesCompatible( castExpr->arg->result, castExpr->result, SymTab::Indexer() ) ) {
@@ -145 +151 @@
 
                         static void strip( Expression *& expr ) {
-                                PassVisitor<StripCasts> stripper;
+                                PassVisitor<StripCasts_old> stripper;
                                 expr = expr->acceptMutator( stripper );
                         }
@@ -153 +159 @@
                         expr->env = oldenv ? oldenv->clone() : new TypeSubstitution;
                         env.makeSubstitution( *expr->env );
-                        StripCasts::strip( expr ); // remove unnecessary casts that may be buried in an expression
+                        StripCasts_old::strip( expr ); // remove unnecessary casts that may be buried in an expression
                 }
 
@@ -237 +243 @@
                                 winner.cost = winner.cvtCost;
                         }
-                        
+
                         // produce ambiguous errors, if applicable
                         if ( winners.size() != 1 ) {
@@ -257 +263 @@
 
                         // xxx - check for ambiguous expressions
-                        
+
                         // output selected choice
                         alt = std::move( choice );
@@ -421 +427 @@
         void Resolver_old::handlePtrType( PtrType * type ) {
                 if ( type->get_dimension() ) {
-                        findSingleExpression( type->dimension, SymTab::SizeType->clone(), indexer );
+                        findSingleExpression( type->dimension, Validate::SizeType->clone(), indexer );
                 }
         }
@@ -446 +452 @@
                 // default value expressions have an environment which shouldn't be there and trips up 
                 // later passes.
-                // xxx - it might be necessary to somehow keep the information from this environment, but I 
+                // xxx - it might be necessary to somehow keep the information from this environment, but I
                 // can't currently see how it's useful.
                 for ( Declaration * d : functionDecl->type->parameters ) {
@@ -797 +803 @@
                 initExpr->expr = nullptr;
                 std::swap( initExpr->env, newExpr->env );
-                // InitExpr may have inferParams in the case where the expression specializes a function 
-                // pointer, and newExpr may already have inferParams of its own, so a simple swap is not 
+                // InitExpr may have inferParams in the case where the expression specializes a function
+                // pointer, and newExpr may already have inferParams of its own, so a simple swap is not
                 // sufficient.
                 newExpr->spliceInferParams( initExpr );
                 delete initExpr;
 
-                // get the actual object's type (may not exactly match what comes back from the resolver 
+                // get the actual object's type (may not exactly match what comes back from the resolver
                 // due to conversions)
                 Type * initContext = currentObject.getCurrentType();
@@ -816 +822 @@
                                         if ( isCharType( pt->get_base() ) ) {
                                                 if ( CastExpr * ce = dynamic_cast< CastExpr * >( newExpr ) ) {
-                                                        // strip cast if we're initializing a char[] with a char *, 
+                                                        // strip cast if we're initializing a char[] with a char *,
                                                         // e.g.  char x[] = "hello";
                                                         newExpr = ce->get_arg();
@@ -839 +845 @@
                 // move cursor into brace-enclosed initializer-list
                 currentObject.enterListInit();
-                // xxx - fix this so that the list isn't copied, iterator should be used to change current 
+                // xxx - fix this so that the list isn't copied, iterator should be used to change current
                 // element
                 std::list<Designation *> newDesignations;
                 for ( auto p : group_iterate(listInit->get_designations(), listInit->get_initializers()) ) {
-                        // iterate designations and initializers in pairs, moving the cursor to the current 
+                        // iterate designations and initializers in pairs, moving the cursor to the current
                         // designated object and resolving the initializer against that object.
                         Designation * des = std::get<0>(p);
@@ -936 +942 @@
         ///////////////////////////////////////////////////////////////////////////
 
+        namespace {
+                /// Finds deleted expressions in an expression tree
+                struct DeleteFinder_new final : public ast::WithShortCircuiting {
+                        const ast::DeletedExpr * delExpr = nullptr;
+
+                        void previsit( const ast::DeletedExpr * expr ) {
+                                if ( delExpr ) { visit_children = false; }
+                                else { delExpr = expr; }
+                        }
+
+                        void previsit( const ast::Expr * ) {
+                                if ( delExpr ) { visit_children = false; }
+                        }
+                };
+
+                /// Check if this expression is or includes a deleted expression
+                const ast::DeletedExpr * findDeletedExpr( const ast::Expr * expr ) {
+                        ast::Pass<DeleteFinder_new> finder;
+                        expr->accept( finder );
+                        return finder.pass.delExpr;
+                }
+
+                /// Calls the CandidateFinder and finds the single best candidate
+                CandidateRef findUnfinishedKindExpression(
+                        const ast::Expr * untyped, const ast::SymbolTable & symtab, const std::string & kind, 
+                        std::function<bool(const Candidate &)> pred, ResolvMode mode = {}
+                ) {
+                        if ( ! untyped ) return nullptr;
+
+                        // xxx - this isn't thread-safe, but should work until we parallelize the resolver
+                        static unsigned recursion_level = 0;
+
+                        ++recursion_level;
+                        ast::TypeEnvironment env;
+                        CandidateFinder finder{ symtab, env };
+                        finder.find( untyped, recursion_level == 1 ? mode.atTopLevel() : mode );
+                        --recursion_level;
+
+                        // produce a filtered list of candidates
+                        CandidateList candidates;
+                        for ( auto & cand : finder.candidates ) {
+                                if ( pred( *cand ) ) { candidates.emplace_back( cand ); }
+                        }
+
+                        // produce invalid error if no candidates
+                        if ( candidates.empty() ) {
+                                SemanticError( untyped, 
+                                        toString( "No reasonable alternatives for ", kind, (kind != "" ? " " : ""), 
+                                        "expression: ") );
+                        }
+
+                        // search for cheapest candidate
+                        CandidateList winners;
+                        bool seen_undeleted = false;
+                        for ( CandidateRef & cand : candidates ) {
+                                int c = winners.empty() ? -1 : cand->cost.compare( winners.front()->cost );
+
+                                if ( c > 0 ) continue;  // skip more expensive than winner
+
+                                if ( c < 0 ) {
+                                        // reset on new cheapest
+                                        seen_undeleted = ! findDeletedExpr( cand->expr );
+                                        winners.clear();
+                                } else /* if ( c == 0 ) */ {
+                                        if ( findDeletedExpr( cand->expr ) ) {
+                                                // skip deleted expression if already seen one equivalent-cost not
+                                                if ( seen_undeleted ) continue;
+                                        } else if ( ! seen_undeleted ) {
+                                                // replace list of equivalent-cost deleted expressions with one non-deleted
+                                                winners.clear();
+                                                seen_undeleted = true;
+                                        }
+                                }
+
+                                winners.emplace_back( std::move( cand ) );
+                        }
+
+                        // promote candidate.cvtCost to .cost
+                        for ( CandidateRef & cand : winners ) {
+                                cand->cost = cand->cvtCost;
+                        }
+
+                        // produce ambiguous errors, if applicable
+                        if ( winners.size() != 1 ) {
+                                std::ostringstream stream;
+                                stream << "Cannot choose between " << winners.size() << " alternatives for " 
+                                        << kind << (kind != "" ? " " : "") << "expression\n";
+                                ast::print( stream, untyped );
+                                stream << " Alternatives are:\n";
+                                print( stream, winners, 1 );
+                                SemanticError( untyped->location, stream.str() );
+                        }
+
+                        // single selected choice
+                        CandidateRef & choice = winners.front();
+
+                        // fail on only expression deleted
+                        if ( ! seen_undeleted ) {
+                                SemanticError( untyped->location, choice->expr.get(), "Unique best alternative "
+                                "includes deleted identifier in " );
+                        }
+
+                        return std::move( choice );
+                }
+
+                /// Strips extraneous casts out of an expression
+                struct StripCasts_new final {
+                        const ast::Expr * postmutate( const ast::CastExpr * castExpr ) {
+                                if ( 
+                                        castExpr->isGenerated 
+                                        && typesCompatible( castExpr->arg->result, castExpr->result ) 
+                                ) {
+                                        // generated cast is the same type as its argument, remove it after keeping env
+                                        ast::ptr<ast::Expr> arg = castExpr->arg;
+                                        arg.get_and_mutate()->env = castExpr->env;
+                                        return arg;
+                                }
+                                return castExpr;
+                        }
+
+                        static void strip( ast::ptr< ast::Expr > & expr ) {
+                                ast::Pass< StripCasts_new > stripper;
+                                expr = expr->accept( stripper );
+                        }
+                };
+
+                /// Establish post-resolver invariants for expressions
+                void finishExpr( 
+                        ast::ptr< ast::Expr > & expr, const ast::TypeEnvironment & env, 
+                        const ast::TypeSubstitution * oldenv = nullptr
+                ) {
+                        // set up new type substitution for expression
+                        ast::ptr< ast::TypeSubstitution > newenv = 
+                                 oldenv ? oldenv : new ast::TypeSubstitution{};
+                        env.writeToSubstitution( *newenv.get_and_mutate() );
+                        expr.get_and_mutate()->env = std::move( newenv );
+                        // remove unncecessary casts
+                        StripCasts_new::strip( expr );
+                }
+                
+                /// resolve `untyped` to the expression whose candidate satisfies `pred` with the 
+                /// lowest cost, returning the resolved version
+                ast::ptr< ast::Expr > findKindExpression(
+                        const ast::Expr * untyped, const ast::SymbolTable & symtab, const std::string & kind, 
+                        std::function<bool(const Candidate &)> pred, ResolvMode mode = {}
+                ) {
+                        if ( ! untyped ) return {};
+                        CandidateRef choice = 
+                                findUnfinishedKindExpression( untyped, symtab, kind, pred, mode );
+                        finishExpr( choice->expr, choice->env, untyped->env );
+                        return std::move( choice->expr );
+                }
+
+                /// Predicate for "Candidate has integral type"
+                bool hasIntegralType( const Candidate & i ) {
+                        const ast::Type * type = i.expr->result;
+                        
+                        if ( auto bt = dynamic_cast< const ast::BasicType * >( type ) ) {
+                                return bt->isInteger();
+                        } else if ( 
+                                dynamic_cast< const ast::EnumInstType * >( type ) 
+                                || dynamic_cast< const ast::ZeroType * >( type )
+                                || dynamic_cast< const ast::OneType * >( type )
+                        ) {
+                                return true;
+                        } else return false;
+                }
+
+                /// Resolve `untyped` as an integral expression, returning the resolved version
+                ast::ptr< ast::Expr > findIntegralExpression( 
+                        const ast::Expr * untyped, const ast::SymbolTable & symtab 
+                ) {
+                        return findKindExpression( untyped, symtab, "condition", hasIntegralType );
+                }
+        }
+
         class Resolver_new final 
-        : public ast::WithIndexer, public ast::WithGuards, public ast::WithVisitorRef<Resolver_new>, 
-          public ast::WithShortCircuiting, public ast::WithStmtsToAdd<> {
-                  
+        : public ast::WithSymbolTable, public ast::WithGuards, 
+          public ast::WithVisitorRef<Resolver_new>, public ast::WithShortCircuiting, 
+          public ast::WithStmtsToAdd<> {
+        
+                ast::ptr< ast::Type > functionReturn = nullptr;
+                // ast::CurrentObject currentObject = nullptr;
+                bool inEnumDecl = false;
+
         public: 
                 Resolver_new() = default;
-                Resolver_new( const ast::SymbolTable & syms ) { /*symtab = syms;*/ }
-
-                void previsit( ast::FunctionDecl * functionDecl );
-                ast::DeclWithType * postvisit( ast::FunctionDecl * functionDecl );
-                void previsit( ast::ObjectDecl * objectDecl );
-                void previsit( ast::EnumDecl * enumDecl );
-                void previsit( ast::StaticAssertDecl * assertDecl );
-
-                void previsit( ast::ArrayType * at );
-                void previsit( ast::PointerType * pt );
-
-                void previsit( ast::ExprStmt * exprStmt );
-                void previsit( ast::AsmExpr * asmExpr );
-                void previsit( ast::AsmStmt * asmStmt );
-                void previsit( ast::IfStmt * ifStmt );
-                void previsit( ast::WhileStmt * whileStmt );
-                void previsit( ast::ForStmt * forStmt );
-                void previsit( ast::SwitchStmt * switchStmt );
-                void previsit( ast::CaseStmt * caseStmt );
-                void previsit( ast::BranchStmt * branchStmt );
-                void previsit( ast::ReturnStmt * returnStmt );
-                void previsit( ast::ThrowStmt * throwStmt );
-                void previsit( ast::CatchStmt * catchStmt );
-                void previsit( ast::WaitForStmt * stmt );
-
-                void previsit( ast::SingleInit * singleInit );
-                void previsit( ast::ListInit * listInit );
-                void previsit( ast::ConstructorInit * ctorInit );
+                Resolver_new( const ast::SymbolTable & syms ) { symtab = syms; }
+
+                void previsit( const ast::FunctionDecl * );
+                const ast::FunctionDecl * postvisit( const ast::FunctionDecl * );
+                void previsit( const ast::ObjectDecl * );
+                void previsit( const ast::EnumDecl * );
+                const ast::StaticAssertDecl * previsit( const ast::StaticAssertDecl * );
+
+                void previsit( const ast::ArrayType * );
+                void previsit( const ast::PointerType * );
+
+                void previsit( const ast::ExprStmt * );
+                void previsit( const ast::AsmExpr * );
+                void previsit( const ast::AsmStmt * );
+                void previsit( const ast::IfStmt * );
+                void previsit( const ast::WhileStmt * );
+                void previsit( const ast::ForStmt * );
+                void previsit( const ast::SwitchStmt * );
+                void previsit( const ast::CaseStmt * );
+                void previsit( const ast::BranchStmt * );
+                void previsit( const ast::ReturnStmt * );
+                void previsit( const ast::ThrowStmt * );
+                void previsit( const ast::CatchStmt * );
+                void previsit( const ast::WaitForStmt * );
+
+                void previsit( const ast::SingleInit * );
+                void previsit( const ast::ListInit * );
+                void previsit( const ast::ConstructorInit * );
         };
 
@@ -977 +1164 @@
         }
 
-        void previsit( ast::FunctionDecl * functionDecl ) {
-                #warning unimplemented; Resolver port in progress
-                (void)functionDecl;
-                assert(false);
-        }
-
-        ast::DeclWithType * postvisit( ast::FunctionDecl * functionDecl ) {
-                #warning unimplemented; Resolver port in progress
-                (void)functionDecl;
-                assert(false);
-                return nullptr;
-        }
-
-        void previsit( ast::ObjectDecl * objectDecl ) {
+        void Resolver_new::previsit( const ast::FunctionDecl * functionDecl ) {
+                GuardValue( functionReturn );
+                functionReturn = extractResultType( functionDecl->type );
+        }
+
+        const ast::FunctionDecl * Resolver_new::postvisit( const ast::FunctionDecl * functionDecl ) {
+                // default value expressions have an environment which shouldn't be there and trips up 
+                // later passes.
+                ast::ptr< ast::FunctionDecl > ret = functionDecl;
+                for ( unsigned i = 0; i < functionDecl->type->params.size(); ++i ) {
+                        const ast::ptr<ast::DeclWithType> & d = functionDecl->type->params[i];
+                        
+                        if ( const ast::ObjectDecl * obj = d.as< ast::ObjectDecl >() ) {
+                                if ( const ast::SingleInit * init = obj->init.as< ast::SingleInit >() ) {
+                                        if ( init->value->env == nullptr ) continue;
+                                        // clone initializer minus the initializer environment
+                                        strict_dynamic_cast< ast::SingleInit * >(
+                                                strict_dynamic_cast< ast::ObjectDecl * >( 
+                                                        ret.get_and_mutate()->type.get_and_mutate()->params[i].get_and_mutate()
+                                                )->init.get_and_mutate()
+                                        )->value.get_and_mutate()->env = nullptr;
+                                }
+                        }
+                }
+                return ret.get();
+        }
+
+        void Resolver_new::previsit( const ast::ObjectDecl * objectDecl ) {
                 #warning unimplemented; Resolver port in progress
                 (void)objectDecl;
@@ -996 +1197 @@
         }
 
-        void previsit( ast::EnumDecl * enumDecl ) {
-                #warning unimplemented; Resolver port in progress
-                (void)enumDecl;
-                assert(false);
-        }
-
-        void previsit( ast::StaticAssertDecl * assertDecl ) {
-                #warning unimplemented; Resolver port in progress
-                (void)assertDecl;
-                assert(false);
-        }
-
-        void previsit( ast::ArrayType * at ) {
+        void Resolver_new::previsit( const ast::EnumDecl * ) {
+                // in case we decide to allow nested enums
+                GuardValue( inEnumDecl );
+                inEnumDecl = false;
+        }
+
+        const ast::StaticAssertDecl * Resolver_new::previsit( 
+                const ast::StaticAssertDecl * assertDecl 
+        ) {
+                ast::ptr< ast::Expr > cond = findIntegralExpression( assertDecl->cond, symtab );
+                if ( cond == assertDecl->cond ) return assertDecl;
+                
+                ast::StaticAssertDecl * ret = mutate( assertDecl );
+                ret->cond = cond;
+                return ret;
+        }
+
+        void Resolver_new::previsit( const ast::ArrayType * at ) {
                 #warning unimplemented; Resolver port in progress
                 (void)at;
@@ -1014 +1220 @@
         }
 
-        void previsit( ast::PointerType * pt ) {
+        void Resolver_new::previsit( const ast::PointerType * pt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)pt;
@@ -1020 +1226 @@
         }
 
-        void previsit( ast::ExprStmt * exprStmt ) {
+        void Resolver_new::previsit( const ast::ExprStmt * exprStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)exprStmt;
@@ -1026 +1232 @@
         }
 
-        void previsit( ast::AsmExpr * asmExpr ) {
+        void Resolver_new::previsit( const ast::AsmExpr * asmExpr ) {
                 #warning unimplemented; Resolver port in progress
                 (void)asmExpr;
@@ -1032 +1238 @@
         }
 
-        void previsit( ast::AsmStmt * asmStmt ) {
+        void Resolver_new::previsit( const ast::AsmStmt * asmStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)asmStmt;
@@ -1038 +1244 @@
         }
 
-        void previsit( ast::IfStmt * ifStmt ) {
+        void Resolver_new::previsit( const ast::IfStmt * ifStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)ifStmt;
@@ -1044 +1250 @@
         }
 
-        void previsit( ast::WhileStmt * whileStmt ) {
+        void Resolver_new::previsit( const ast::WhileStmt * whileStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)whileStmt;
@@ -1050 +1256 @@
         }
 
-        void previsit( ast::ForStmt * forStmt ) {
+        void Resolver_new::previsit( const ast::ForStmt * forStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)forStmt;
@@ -1056 +1262 @@
         }
 
-        void previsit( ast::SwitchStmt * switchStmt ) {
+        void Resolver_new::previsit( const ast::SwitchStmt * switchStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)switchStmt;
@@ -1062 +1268 @@
         }
 
-        void previsit( ast::CaseStmt * caseStmt ) {
+        void Resolver_new::previsit( const ast::CaseStmt * caseStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)caseStmt;
@@ -1068 +1274 @@
         }
 
-        void previsit( ast::BranchStmt * branchStmt ) {
+        void Resolver_new::previsit( const ast::BranchStmt * branchStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)branchStmt;
@@ -1074 +1280 @@
         }
 
-        void previsit( ast::ReturnStmt * returnStmt ) {
+        void Resolver_new::previsit( const ast::ReturnStmt * returnStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)returnStmt;
@@ -1080 +1286 @@
         }
 
-        void previsit( ast::ThrowStmt * throwStmt ) {
+        void Resolver_new::previsit( const ast::ThrowStmt * throwStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)throwStmt;
@@ -1086 +1292 @@
         }
 
-        void previsit( ast::CatchStmt * catchStmt ) {
+        void Resolver_new::previsit( const ast::CatchStmt * catchStmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)catchStmt;
@@ -1092 +1298 @@
         }
 
-        void previsit( ast::WaitForStmt * stmt ) {
+        void Resolver_new::previsit( const ast::WaitForStmt * stmt ) {
                 #warning unimplemented; Resolver port in progress
                 (void)stmt;
@@ -1098 +1304 @@
         }
 
-        void previsit( ast::SingleInit * singleInit ) {
+        void Resolver_new::previsit( const ast::SingleInit * singleInit ) {
                 #warning unimplemented; Resolver port in progress
                 (void)singleInit;
@@ -1104 +1310 @@
         }
 
-        void previsit( ast::ListInit * listInit ) {
+        void Resolver_new::previsit( const ast::ListInit * listInit ) {
                 #warning unimplemented; Resolver port in progress
                 (void)listInit;
@@ -1110 +1316 @@
         }
 
-        void previsit( ast::ConstructorInit * ctorInit ) {
+        void Resolver_new::previsit( const ast::ConstructorInit * ctorInit ) {
                 #warning unimplemented; Resolver port in progress
                 (void)ctorInit;