Changes in src/Tuples/Explode.h [490ff5c3:7870799]

File:

• src/Tuples/Explode.h (modified) (6 diffs)

src/Tuples/Explode.h

@@ -9 +9 @@
 // Author           : Rob Schluntz
 // Created On       : Wed Nov 9 13:12:24 2016
-// Last Modified By : Peter A. Buhr
-// Last Modified On : Sat Jul 22 09:55:16 2017
-// Update Count     : 3
+// Last Modified By : Andrew Beach
+// Last Modified On : Mon Jun 17 14:36:00 2019
+// Update Count     : 4
 //
 
@@ -19 +19 @@
 #include <utility>                      // for forward
 
+#include "AST/Expr.hpp"
 #include "ResolvExpr/Alternative.h"     // for Alternative, AltList
+#include "ResolvExpr/Candidate.hpp"     // for Candidate, CandidateList
 #include "ResolvExpr/ExplodedActual.h"  // for ExplodedActual
+#include "ResolvExpr/ExplodedArg.hpp"   // for ExplodedArg
 #include "SynTree/Expression.h"         // for Expression, UniqueExpr, AddressExpr
 #include "SynTree/Type.h"               // for TupleType, Type
 #include "Tuples.h"                     // for maybeImpure
+
+namespace ast {
+        class SymbolTable;
+}
 
 namespace SymTab {
@@ -44 +51 @@
         template<typename OutputIterator>
         void append( OutputIterator out, Expression* expr, const ResolvExpr::TypeEnvironment& env,
+                        const ResolvExpr::OpenVarSet& openVars, const ResolvExpr::AssertionList& need,
                         const ResolvExpr::Cost& cost, const ResolvExpr::Cost& cvtCost ) {
-                *out++ = ResolvExpr::Alternative{ expr, env, cost, cvtCost };
+                *out++ = ResolvExpr::Alternative{ expr, env, openVars, need, cost, cvtCost };
         }
 
         /// Append alternative to an ExplodedActual
         static inline void append( ResolvExpr::ExplodedActual& ea, Expression* expr,
-                        const ResolvExpr::TypeEnvironment&, const ResolvExpr::Cost&, const ResolvExpr::Cost& ) {
+                        const ResolvExpr::TypeEnvironment&, const ResolvExpr::OpenVarSet&,
+                        const ResolvExpr::AssertionList&, const ResolvExpr::Cost&, const ResolvExpr::Cost& ) {
                 ea.exprs.emplace_back( expr );
-                /// xxx -- merge environment, cost?
+                /// xxx -- merge environment, openVars, need, cost?
         }
 
@@ -68 +77 @@
                                         // distribute reference cast over all components
                                         append( std::forward<Output>(out), distributeReference( alt.release_expr() ),
-                                                alt.env, alt.cost, alt.cvtCost );
+                                                alt.env, alt.openVars, alt.need, alt.cost, alt.cvtCost );
                                 }
                                 // in tuple assignment, still need to handle the other cases, but only if not already handled here (don't want to output too many alternatives)
@@ -102 +111 @@
                 } else {
                         // atomic (non-tuple) type - output a clone of the expression in a new alternative
-                        append( std::forward<Output>(out), expr->clone(), alt.env, alt.cost, alt.cvtCost );
+                        append( std::forward<Output>(out), expr->clone(), alt.env, alt.openVars, alt.need,
+                                alt.cost, alt.cvtCost );
                 }
         }
@@ -127 +137 @@
                 explode( alts.begin(), alts.end(), indexer, std::forward<Output>(out), isTupleAssign );
         }
+
+const ast::Expr * distributeReference( const ast::Expr * );
+
+/// Append candidate to an OutputIterator of Candidates.
+template<typename OutputIterator>
+void append( OutputIterator out, const ast::Expr * expr, const ast::TypeEnvironment & env,
+                const ast::OpenVarSet & open, const ast::AssertionList & need,
+                const ResolvExpr::Cost & cost, const ResolvExpr::Cost & cvtCost ) {
+        ast::TypeEnvironment copyEnv = env;
+        ast::OpenVarSet copyOpen = open;
+        ast::AssertionSet set;
+        mergeAssertionSet( set, need );
+        *out++ = std::make_shared<ResolvExpr::Candidate>( expr, std::move( copyEnv ),
+                std::move( copyOpen ), std::move( set ), cost, cvtCost );
+}
+
+/// Append candidate to an ExplodedArg.
+static inline void append( ResolvExpr::ExplodedArg& ea, const ast::Expr * expr,
+                const ast::TypeEnvironment&, const ast::OpenVarSet&,
+                const ast::AssertionList&, const ResolvExpr::Cost&, const ResolvExpr::Cost& ) {
+        // I'm not sure why most of the arguments are unused. But they were in the old version.
+        ea.exprs.emplace_back( expr );
+}
+
+/// Check if the expression is a cast to a reference type, return it if it is.
+static inline const ast::CastExpr * isReferenceCast( const ast::Expr * expr ) {
+        if ( const ast::CastExpr * cast = dynamic_cast< const ast::CastExpr * >( expr ) ) {
+                if ( dynamic_cast< const ast::ReferenceType * >( cast->result.get() ) ) {
+                        return cast;
+                }
+        }
+        return nullptr;
+}
+
+/// helper function (indirectely) used by explode
+template< typename Output >
+void explodeRecursive(
+        const ast::CastExpr *, const ResolvExpr::Candidate &,
+        const ast::SymbolTable &, Output &&
+) {
+}
+
+/// helper function used by explode
+template< typename Output >
+void explodeUnique(
+        const ast::ptr< ast::Expr > & expr, const ResolvExpr::Candidate & arg,
+        const ast::SymbolTable & symtab, Output && out, bool isTupleAssign
+) {
+        // Tuple assignment can use a faster method if it is cast. Uses recursive exploding.
+        if ( isTupleAssign ) if ( const ast::CastExpr * castExpr = isReferenceCast( expr ) ) {
+                ResolvExpr::CandidateList candidates;
+                explodeUnique( castExpr->arg, arg, symtab, back_inserter( candidates ), true );
+                for ( ResolvExpr::CandidateRef & cand : candidates ) {
+                        // Distribute the reference cast over all components of the candidate.
+                        append( std::forward<Output>(out), distributeReference( cand->expr ), cand->env,
+                                cand->open, cand->need, cand->cost, cand->cvtCost );
+                }
+                return;
+        }
+        const ast::Type * res = expr->result->stripReferences();
+        if ( const ast::TupleType * tupleType = dynamic_cast< const ast::TupleType * >( res ) ) {
+                if ( const ast::ptr< ast::TupleExpr > & tupleExpr = expr.as< ast::TupleExpr >() ) {
+                        // Open the tuple expr and continue on its components.
+                        for ( const ast::Expr * expr : tupleExpr->exprs ) {
+                                explodeUnique( expr, arg, symtab, std::forward<Output>(out), isTupleAssign );
+                        }
+                } else {
+                        ast::ptr< ast::Expr > local = expr;
+                        // Expressions which may have side effects require a single unique instance.
+                        if ( Tuples::maybeImpureIgnoreUnique( local ) ) {
+                                local = new ast::UniqueExpr( local->location, local );
+                        }
+                        // Cast a reference away to a value-type to allow further explosion.
+                        if ( dynamic_cast< const ast::ReferenceType *>( local->result.get() ) ) {
+                                local = new ast::CastExpr{ local, tupleType };
+                        }
+                        // Now we have to go across the tuple via indexing.
+                        for ( unsigned int i = 0 ; i < tupleType->size() ; ++i ) {
+                                ast::TupleIndexExpr * idx = new ast::TupleIndexExpr( local->location, local, i );
+                                explodeUnique( idx, arg, symtab, std::forward<Output>(out), isTupleAssign );
+                                // TODO: We need more input to figure out the exact lifetimes of these types.
+                                // delete idx;
+                        }
+                        // delete local;
+                }
+        } else {
+                // For atomic/non-tuple types, no explosion is used.
+                append( std::forward<Output>(out), expr, arg.env, arg.open, arg.need, arg.cost,
+                        arg.cvtCost );
+        }
+}
+
+/// expands a tuple-valued candidate into multiple candidates, each with a non-tuple type
+template< typename Output >
+void explode(
+        const ResolvExpr::Candidate & arg, const ast::SymbolTable & symtab, Output && out,
+        bool isTupleAssign = false
+) {
+        explodeUnique( arg.expr, arg, symtab, std::forward< Output >( out ), isTupleAssign );
+}
+
+/// explode list of candidates into flattened list of candidates
+template< typename Output >
+void explode(
+        const ResolvExpr::CandidateList & cands, const ast::SymbolTable & symtab, Output && out,
+        bool isTupleAssign = false
+) {
+        for ( const ResolvExpr::CandidateRef & cand : cands ) {
+                explode( *cand, symtab, std::forward< Output >( out ), isTupleAssign );
+        }
+}
+
 } // namespace Tuples