Merge pull request #2452 from github/filter-gensymed-names

Filter gensymed names

src/Control/Abstract/Primitive.hs

@@ -45,9 +45,9 @@ defineBuiltIn declaration rel accessControl value = withCurrentCallStack callSta
   -- TODO: This span is still wrong.
   declare declaration rel accessControl emptySpan ScopeGraph.Unknown (Just associatedScope)
 
-  param <- gensym
   withScope associatedScope $ do
-    declare (Declaration param) rel accessControl emptySpan ScopeGraph.Unknown Nothing
+    param <- gensym
+    declare (Declaration param) ScopeGraph.Gensym accessControl emptySpan ScopeGraph.Unknown Nothing
 
   slot <- lookupSlot declaration
   value <- builtIn associatedScope value

src/Control/Abstract/ScopeGraph.hs

@@ -3,6 +3,7 @@
 module Control.Abstract.ScopeGraph
   ( lookup
   , declare
+  , declareMaybeName
   , reference
   , newScope
   , newPreludeScope
@@ -79,6 +80,27 @@ declare decl rel accessControl span kind scope = do
   moduleInfo <- ask @ModuleInfo
   modify (fst . ScopeGraph.declare decl moduleInfo rel accessControl span kind scope currentAddress)
 
+-- | If the provided name is 'Nothing' we want to reflect that the declaration's name was a generated name (gensym).
+-- We use the 'Gensym' relation to indicate that. Otherwise, we use the provided 'relation'.
+declareMaybeName :: ( Carrier sig m
+                    , Member (State (ScopeGraph address)) sig
+                    , Member (Reader (CurrentScope address)) sig
+                    , Member (Reader ModuleInfo) sig
+                    , Member Fresh sig
+                    , Ord address
+                    )
+                 => Maybe Name
+                 -> Relation
+                 -> AccessControl
+                 -> Span
+                 -> Kind
+                 -> Maybe address
+                 -> Evaluator term address value m Name
+declareMaybeName maybeName relation ac span kind scope = do
+  case maybeName of
+    Just name -> declare (Declaration name) relation ac span kind scope >> pure name
+    _         -> gensym >>= \name -> declare (Declaration name) Gensym ac span kind scope >> pure name
+
 putDeclarationScope :: ( Ord address
                        , Member (Reader (CurrentScope address)) sig
                        , Member (State (ScopeGraph address)) sig

src/Data/Abstract/Evaluatable.hs

@@ -30,7 +30,7 @@ import Data.Abstract.Declarations as X
 import Data.Abstract.FreeVariables as X
 import Data.Abstract.Module
 import Data.Abstract.Name as X
-import qualified Data.Abstract.ScopeGraph as ScopeGraph 
+import qualified Data.Abstract.ScopeGraph as ScopeGraph
 import Data.Abstract.ScopeGraph (Relation(..))
 import Data.Abstract.AccessControls.Class as X
 import Data.Language
@@ -192,7 +192,7 @@ defineSelf :: ( Carrier sig m
            => Evaluator term address value m ()
 defineSelf = do
   let self = Declaration X.__self
-  declare self Default Public emptySpan ScopeGraph.Unknown Nothing
+  declare self ScopeGraph.Gensym Public emptySpan ScopeGraph.Unknown Nothing
   slot <- lookupSlot self
   assign slot =<< object =<< currentFrame
 

src/Data/Abstract/ScopeGraph.hs

@@ -86,7 +86,7 @@ instance Ord AccessControl where
   (<=) Public _            = False
 
 
-data Relation = Default | Instance | Prelude
+data Relation = Default | Instance | Prelude | Gensym
   deriving (Eq, Show, Ord, Generic, NFData)
 
 instance Lower Relation where

src/Data/Syntax/Declaration.hs

@@ -28,15 +28,10 @@ instance Diffable Function where
 
 instance Evaluatable Function where
   eval _ _ Function{..} = do
-    name <- maybeM (throwNoNameError functionName) (declaredName functionName)
     span <- ask @Span
-    associatedScope <- declareFunction name ScopeGraph.Public span ScopeGraph.Function
+    (name, associatedScope) <- declareFunction (declaredName functionName) ScopeGraph.Public span ScopeGraph.Function
 
-    params <- withScope associatedScope . for functionParameters $ \paramNode -> do
-      param <- maybeM (throwNoNameError paramNode) (declaredName paramNode)
-
-      let paramSpan = getSpan paramNode
-      param <$ declare (Declaration param) Default ScopeGraph.Public paramSpan ScopeGraph.Parameter Nothing
+    params <- withScope associatedScope . for functionParameters $ \paramNode -> declareMaybeName (declaredName paramNode) Default ScopeGraph.Public (getSpan paramNode) ScopeGraph.Parameter Nothing
 
     addr <- lookupSlot (Declaration name)
     v <- function name params functionBody associatedScope
@@ -50,17 +45,17 @@ declareFunction :: ( Carrier sig m
                    , Member Fresh sig
                    , Ord address
                    )
-                => Name
+                => Maybe Name
                 -> ScopeGraph.AccessControl
                 -> Span
                 -> ScopeGraph.Kind
-                -> Evaluator term address value m address
+                -> Evaluator term address value m (Name, address)
 declareFunction name accessControl span kind = do
   currentScope' <- currentScope
   let lexicalEdges = Map.singleton Lexical [ currentScope' ]
   associatedScope <- newScope lexicalEdges
-  declare (Declaration name) Default accessControl span kind (Just associatedScope)
-  pure associatedScope
+  name' <- declareMaybeName name Default accessControl span kind (Just associatedScope)
+  pure (name', associatedScope)
 
 instance Tokenize Function where
   tokenize Function{..} = within' Scope.Function $ do
@@ -92,16 +87,13 @@ instance Diffable Method where
 -- local environment.
 instance Evaluatable Method where
   eval _ _ Method{..} = do
-    name <- maybeM (throwNoNameError methodName) (declaredName methodName)
     span <- ask @Span
-    associatedScope <- declareFunction name methodAccessControl span ScopeGraph.Method
+    (name, associatedScope) <- declareFunction (declaredName methodName) methodAccessControl span ScopeGraph.Method
 
     params <- withScope associatedScope $ do
       -- TODO: Should we give `self` a special Relation?
-      declare (Declaration __self) Prelude ScopeGraph.Public emptySpan ScopeGraph.Unknown Nothing
-      for methodParameters $ \paramNode -> do
-        param <- maybeM (throwNoNameError paramNode) (declaredName paramNode)
-        param <$ declare (Declaration param) Default ScopeGraph.Public span ScopeGraph.Parameter Nothing
+      declare (Declaration __self) ScopeGraph.Prelude ScopeGraph.Public emptySpan ScopeGraph.Unknown Nothing
+      for methodParameters $ \paramNode -> declareMaybeName (declaredName paramNode) Default ScopeGraph.Public (getSpan paramNode) ScopeGraph.Parameter Nothing
 
     addr <- lookupSlot (Declaration name)
     v <- function name params methodBody associatedScope
@@ -144,9 +136,8 @@ instance Declarations1 RequiredParameter where
 -- TODO: Implement Eval instance for RequiredParameter
 instance Evaluatable RequiredParameter where
   eval _ _ RequiredParameter{..} = do
-    name <- maybeM (throwNoNameError requiredParameter) (declaredName requiredParameter)
     span <- ask @Span
-    declare (Declaration name) Default ScopeGraph.Public span ScopeGraph.RequiredParameter Nothing
+    _ <- declareMaybeName (declaredName requiredParameter) Default ScopeGraph.Public span ScopeGraph.RequiredParameter Nothing
     unit
 
 
@@ -170,9 +161,8 @@ instance Evaluatable VariableDeclaration where
   eval _    _ (VariableDeclaration [])   = unit
   eval eval _ (VariableDeclaration decs) = do
     for_ decs $ \declaration -> do
-      name <- maybeM (throwNoNameError declaration) (declaredName declaration)
-      let declarationSpan = getSpan declaration
-      declare (Declaration name) Default ScopeGraph.Public declarationSpan ScopeGraph.VariableDeclaration Nothing
+      let span = getSpan declaration
+      _ <- declareMaybeName (declaredName declaration) Default ScopeGraph.Public span ScopeGraph.VariableDeclaration Nothing
       eval declaration
     unit
 
@@ -209,10 +199,8 @@ data PublicFieldDefinition a = PublicFieldDefinition
 instance Evaluatable PublicFieldDefinition where
   eval eval _ PublicFieldDefinition{..} = do
     span <- ask @Span
-    propertyName <- maybeM (throwNoNameError publicFieldPropertyName) (declaredName publicFieldPropertyName)
-
-    declare (Declaration propertyName) Instance publicFieldAccessControl span ScopeGraph.PublicField Nothing
-    slot <- lookupSlot (Declaration propertyName)
+    name <- declareMaybeName (declaredName publicFieldPropertyName) Instance publicFieldAccessControl span ScopeGraph.PublicField Nothing
+    slot <- lookupSlot (Declaration name)
     value <- eval publicFieldValue
     assign slot value
     unit
@@ -236,12 +224,13 @@ instance Diffable Class where
 
 instance Evaluatable Class where
   eval eval _ Class{..} = do
-    name <- maybeM (throwNoNameError classIdentifier) (declaredName classIdentifier)
     span <- ask @Span
     currentScope' <- currentScope
 
     superScopes <- for classSuperclasses $ \superclass -> do
-      name <- maybeM (throwNoNameError superclass) (declaredName superclass)
+      name <- case declaredName superclass of
+                Just name -> pure name
+                Nothing   -> gensym
       scope <- associatedScope (Declaration name)
       slot <- lookupSlot (Declaration name)
       superclassFrame <- scopedEnvironment =<< deref slot
@@ -253,7 +242,7 @@ instance Evaluatable Class where
         current = (Lexical, ) <$> pure (pure currentScope')
         edges = Map.fromList (superclassEdges <> current)
     classScope <- newScope edges
-    declare (Declaration name) Default ScopeGraph.Public span ScopeGraph.Class (Just classScope)
+    name <- declareMaybeName (declaredName classIdentifier) Default ScopeGraph.Public span ScopeGraph.Class (Just classScope)
 
     let frameEdges = Map.singleton Superclass (Map.fromList (catMaybes superScopes))
     classFrame <- newFrame classScope frameEdges
@@ -323,13 +312,11 @@ data TypeAlias a = TypeAlias { typeAliasContext :: ![a], typeAliasIdentifier ::
 
 instance Evaluatable TypeAlias where
   eval _ _ TypeAlias{..} = do
-    name <- maybeM (throwNoNameError typeAliasIdentifier) (declaredName typeAliasIdentifier)
+    -- This use of `throwNoNameError` is good -- we aren't declaring something new so `declareMaybeName` is not useful here.
     kindName <- maybeM (throwNoNameError typeAliasKind) (declaredName typeAliasKind)
-
     span <- ask @Span
     assocScope <- associatedScope (Declaration kindName)
-    -- TODO: Should we consider a special Relation for `TypeAlias`?
-    declare (Declaration name) Default ScopeGraph.Public span ScopeGraph.TypeAlias assocScope
+    name <- declareMaybeName (declaredName typeAliasIdentifier) Default ScopeGraph.Public span ScopeGraph.TypeAlias assocScope
 
     slot <- lookupSlot (Declaration name)
     kindSlot <- lookupSlot (Declaration kindName)

src/Data/Syntax/Expression.hs

@@ -427,6 +427,7 @@ instance Evaluatable MemberAccess where
     let lhsAccessControl = fromMaybe Public (termToAccessControl lhs)
     infos <- declarationsByAccessControl rhsScope lhsAccessControl
 
+    -- This means we always throw an 'AccessControlError' whenever we have a rhs term whose 'declaredName' is 'Nothing'.
     rhsName <- maybeM (throwNoNameError rhs) (declaredName rhs)
     rhsValue' <- case find (\Info{..} -> Declaration rhsName == infoDeclaration) infos of
       Just _  -> pure rhsValue

src/Data/Syntax/Statement.hs

@@ -121,13 +121,13 @@ data Let a  = Let { letVariable :: !a, letValue :: !a, letBody :: !a }
 
 instance Evaluatable Let where
   eval eval _ Let{..} = do
-    name <- maybeM (throwNoNameError letVariable) (declaredName letVariable)
-    letSpan <- ask @Span
+    -- This use of 'throwNoNameError' is okay until we have a better way of mapping gensym names to terms in the scope graph.
     valueName <- maybeM (throwNoNameError letValue) (declaredName letValue)
     assocScope <- associatedScope (Declaration valueName)
 
     _ <- withLexicalScopeAndFrame $ do
-      declare (Declaration name) Default Public letSpan ScopeGraph.Let assocScope
+      letSpan <- ask @Span
+      name <- declareMaybeName (declaredName letVariable) Default Public letSpan ScopeGraph.Let assocScope
       letVal <- eval letValue
       slot <- lookupSlot (Declaration name)
       assign slot letVal

src/Language/Go/Syntax.hs

@@ -75,11 +75,10 @@ data QualifiedImport a = QualifiedImport { qualifiedImportFrom :: !ImportPath, q
 instance Evaluatable QualifiedImport where
   eval _ _ (QualifiedImport importPath aliasTerm) = do
     paths <- resolveGoImport importPath
-    alias <- maybeM (throwNoNameError aliasTerm) (declaredName aliasTerm)
     span <- ask @Span
     scopeAddress <- newScope mempty
-    declare (Declaration alias) Default Public span ScopeGraph.QualifiedImport (Just scopeAddress)
-    aliasSlot <- lookupSlot (Declaration alias)
+    name <- declareMaybeName (declaredName aliasTerm) Default Public span ScopeGraph.QualifiedImport (Just scopeAddress)
+    aliasSlot <- lookupSlot (Declaration name)
 
     withScope scopeAddress $ do
       let

src/Language/PHP/Syntax.hs

@@ -172,6 +172,7 @@ data QualifiedName a = QualifiedName { name :: a, identifier :: a }
 
 instance Evaluatable QualifiedName where
   eval _ _ (QualifiedName obj iden) = do
+    -- TODO: Consider gensym'ed names used for References.
     name <- maybeM (throwNoNameError obj) (declaredName obj)
     let objSpan = getSpan obj
     reference (Reference name) objSpan ScopeGraph.Identifier (Declaration name)

src/Language/Python/Syntax.hs

@@ -187,6 +187,7 @@ newtype QualifiedImport a = QualifiedImport { qualifiedImportFrom :: NonEmpty a
 -- import a.b.c
 instance Evaluatable QualifiedImport where
   eval _ _ (QualifiedImport qualifiedNames) = do
+    -- TODO: Consider gensym'ed names for imports.
     qualifiedName <- fmap (T.unpack . formatName) <$> traverse (\term -> maybeM (throwNoNameError term) (declaredName term)) qualifiedNames
     modulePaths <- resolvePythonModules (QualifiedName qualifiedName)
     let namesAndPaths = toList (NonEmpty.zip (NonEmpty.zip qualifiedNames (Data.Abstract.Evaluatable.name . T.pack <$> qualifiedName)) modulePaths)

src/Language/Ruby/Syntax.hs

@@ -181,7 +181,9 @@ instance Diffable Class where
 
 instance Evaluatable Class where
   eval eval _ Class{..} = do
-    name <- maybeM (throwNoNameError classIdentifier) (declaredName classIdentifier)
+    (name, relation) <- case declaredName classIdentifier of
+                          Just name -> pure (name, Default)
+                          _         -> gensym >>= \name -> pure (name, Gensym)
     span <- ask @Span
     currentScope' <- currentScope
 
@@ -210,7 +212,7 @@ instance Evaluatable Class where
             current = (Lexical, ) <$> pure (pure currentScope')
             edges = Map.fromList (superclassEdges <> current)
         classScope <- newScope edges
-        declare (Declaration name) Default Public span ScopeGraph.Class (Just classScope)
+        declare (Declaration name) relation Public span ScopeGraph.Class (Just classScope)
 
         let frameEdges = Map.singleton Superclass (Map.fromList (catMaybes superScopes))
         childFrame <- newFrame classScope frameEdges
@@ -241,7 +243,9 @@ data Module a = Module { moduleIdentifier :: !a, moduleStatements :: ![a] }
 
 instance Evaluatable Module where
   eval eval _ Module{..} =  do
-    name <- maybeM (throwNoNameError moduleIdentifier) (declaredName moduleIdentifier)
+    (name, relation) <- case declaredName moduleIdentifier of
+                          Just name -> pure (name, Default)
+                          _         -> gensym >>= \name -> pure (name, Gensym)
     span <- ask @Span
     currentScope' <- currentScope
 
@@ -260,7 +264,7 @@ instance Evaluatable Module where
       Nothing -> do
         let edges = Map.singleton Lexical [ currentScope' ]
         classScope <- newScope edges
-        declare (Declaration name) Default Public span ScopeGraph.Module (Just classScope)
+        declare (Declaration name) relation Public span ScopeGraph.Module (Just classScope)
 
         currentFrame' <- currentFrame
         let frameEdges = Map.singleton Lexical (Map.singleton currentScope' currentFrame')
@@ -323,10 +327,12 @@ instance Declarations1 Assignment where
 
 instance Evaluatable Assignment where
   eval eval ref Assignment{..} = do
-    lhsName <- maybeM (throwNoNameError assignmentTarget) (declaredName assignmentTarget)
+    (lhsName, relation) <- case declaredName assignmentTarget of
+                             Just name -> pure (name, Default)
+                             _         -> gensym >>= \name -> pure (name, Gensym)
     maybeSlot <- maybeLookupDeclaration (Declaration lhsName)
     assignmentSpan <- ask @Span
-    maybe (declare (Declaration lhsName) Default Public assignmentSpan ScopeGraph.Assignment Nothing) (const (pure ())) maybeSlot
+    maybe (declare (Declaration lhsName) relation Public assignmentSpan ScopeGraph.Assignment Nothing) (const (pure ())) maybeSlot
 
     lhs <- ref assignmentTarget
     rhs <- eval assignmentValue

src/Language/TypeScript/Syntax/Import.hs

@@ -58,10 +58,8 @@ instance Evaluatable QualifiedAliasedImport where
     importScope <- newScope (Map.singleton ScopeGraph.Import [ moduleScope ])
     let scopeMap = Map.singleton moduleScope moduleFrame
     aliasFrame <- newFrame importScope (Map.singleton ScopeGraph.Import scopeMap)
-
-    alias <- maybeM (throwNoNameError aliasTerm) (declaredName aliasTerm)
-    declare (Declaration alias) Default Public span ScopeGraph.QualifiedAliasedImport (Just importScope)
-    aliasSlot <- lookupSlot (Declaration alias)
+    name <- declareMaybeName (declaredName aliasTerm) Default Public span ScopeGraph.QualifiedAliasedImport (Just importScope)
+    aliasSlot <- lookupSlot (Declaration name)
     assign aliasSlot =<< object aliasFrame
 
     unit

src/Language/TypeScript/Syntax/JSX.hs

@@ -76,9 +76,8 @@ instance Declarations1 RequiredParameter where
 
 instance Evaluatable RequiredParameter where
   eval eval ref RequiredParameter{..} = do
-    name <- maybeM (throwNoNameError requiredParameterSubject) (declaredName requiredParameterSubject)
     span <- ask @Span
-    declare (Declaration name) Default Public span ScopeGraph.RequiredParameter Nothing
+    _ <- declareMaybeName (declaredName requiredParameterSubject) Default Public span ScopeGraph.RequiredParameter Nothing
 
     lhs <- ref requiredParameterSubject
     rhs <- eval requiredParameterValue

src/Language/TypeScript/Syntax/TypeScript.hs

@@ -193,7 +193,9 @@ declareModule :: ( AbstractValue term address value m
                 -> [term]
                 -> Evaluator term address value m value
 declareModule eval identifier statements = do
-    name <- maybeM (throwNoNameError identifier) (declaredName identifier)
+    (name, relation) <- case declaredName identifier of
+                          Just name -> pure (name, Default)
+                          _         -> gensym >>= \name -> pure (name, Gensym)
     span <- ask @Span
     currentScope' <- currentScope
 
@@ -212,7 +214,7 @@ declareModule eval identifier statements = do
       Nothing -> do
         let edges = Map.singleton Lexical [ currentScope' ]
         childScope <- newScope edges
-        declare (Declaration name) Default Public span ScopeGraph.Module (Just childScope)
+        declare (Declaration name) relation Public span ScopeGraph.Module (Just childScope)
 
         currentFrame' <- currentFrame
         let frameEdges = Map.singleton Lexical (Map.singleton currentScope' currentFrame')
@@ -257,7 +259,6 @@ instance Declarations a => Declarations (AbstractClass a) where
 
 instance Evaluatable AbstractClass where
   eval eval _ AbstractClass{..} = do
-    name <- maybeM (throwNoNameError abstractClassIdentifier) (declaredName abstractClassIdentifier)
     span <- ask @Span
     currentScope' <- currentScope
 
@@ -274,7 +275,7 @@ instance Evaluatable AbstractClass where
         current = (Lexical, ) <$> pure (pure currentScope')
         edges = Map.fromList (superclassEdges <> current)
     classScope <- newScope edges
-    declare (Declaration name) Default Public span ScopeGraph.AbstractClass (Just classScope)
+    name <- declareMaybeName (declaredName abstractClassIdentifier) Default Public span ScopeGraph.AbstractClass (Just classScope)
 
     let frameEdges = Map.singleton Superclass (Map.fromList (catMaybes superScopes))
     childFrame <- newFrame classScope frameEdges