JS: Move definition of getContainer() to a single rootdef

javascript/ql/src/semmle/javascript/AST.qll

@@ -3,6 +3,7 @@
  */
 
 import javascript
+private import internal.StmtContainers
 
 /**
  * A program element corresponding to JavaScript code, such as an expression
@@ -20,7 +21,7 @@ import javascript
  * abs(-42);
  * ```
  */
-class ASTNode extends @ast_node, Locatable {
+class ASTNode extends @ast_node, NodeInStmtContainer {
   override Location getLocation() { hasLocation(this, result) }
 
   override File getFile() {

javascript/ql/src/semmle/javascript/BasicBlocks.qll

@@ -4,6 +4,7 @@
  */
 
 import javascript
+private import internal.StmtContainers
 
 /**
  * Holds if `nd` starts a new basic block.
@@ -114,7 +115,7 @@ private predicate bbIPostDominates(BasicBlock dom, BasicBlock bb) =
  *
  * At the database level, a basic block is represented by its first control flow node.
  */
-class BasicBlock extends @cfg_node, Locatable {
+class BasicBlock extends @cfg_node, NodeInStmtContainer {
   BasicBlock() { startsBB(this) }
 
   /** Gets a basic block succeeding this one. */
@@ -271,11 +272,6 @@ class BasicBlock extends @cfg_node, Locatable {
     exists(int n | defAt(n, v, d) | not exists(int m | m < n | defAt(m, v, _)))
   }
 
-  /**
-   * Gets the function or script to which this basic block belongs.
-   */
-  StmtContainer getContainer() { result = getFirstNode().getContainer() }
-
   /**
    * Gets the basic block that immediately dominates this basic block.
    */

javascript/ql/src/semmle/javascript/CFG.qll

@@ -274,12 +274,13 @@
  */
 
 import javascript
+private import internal.StmtContainers
 
 /**
  * A node in the control flow graph, which is an expression, a statement,
  * or a synthetic node.
  */
-class ControlFlowNode extends @cfg_node, Locatable {
+class ControlFlowNode extends @cfg_node, Locatable, NodeInStmtContainer {
   /** Gets a node succeeding this node in the CFG. */
   ControlFlowNode getASuccessor() { successor(this, result) }
 
@@ -324,17 +325,6 @@ class ControlFlowNode extends @cfg_node, Locatable {
     // note the override in ControlFlowEntryNode below
   }
 
-  /** Gets the function or toplevel whose CFG this node belongs to. */
-  cached
-  StmtContainer getContainer() {
-    result = this.(Expr).getContainer() or
-    result = this.(Stmt).getContainer() or
-    result = this.(Property).getContainer() or
-    result = this.(PropertyPattern).getContainer() or
-    result = this.(ClassDefinition).getContainer() or
-    result = this.(MemberDeclaration).getContainer()
-  }
-
   /** Gets the basic block this node belongs to. */
   BasicBlock getBasicBlock() { this = result.getANode() }
 
@@ -364,8 +354,6 @@ class SyntheticControlFlowNode extends @synthetic_cfg_node, ControlFlowNode {
 
 /** A synthetic CFG node marking the entry point of a function or toplevel script. */
 class ControlFlowEntryNode extends SyntheticControlFlowNode, @entry_node {
-  override StmtContainer getContainer() { entry_cfg_node(this, result) }
-
   override predicate isUnreachable() { none() }
 
   override string toString() { result = "entry node of " + getContainer().toString() }
@@ -373,8 +361,6 @@ class ControlFlowEntryNode extends SyntheticControlFlowNode, @entry_node {
 
 /** A synthetic CFG node marking the exit of a function or toplevel script. */
 class ControlFlowExitNode extends SyntheticControlFlowNode, @exit_node {
-  override StmtContainer getContainer() { exit_cfg_node(this, result) }
-
   override predicate isAFinalNode() { any() }
 
   override string toString() { result = "exit node of " + getContainer().toString() }
@@ -396,8 +382,6 @@ class GuardControlFlowNode extends SyntheticControlFlowNode, @guard_node {
     this = bb.getANode() or
     dominates(bb.getImmediateDominator())
   }
-
-  override StmtContainer getContainer() { result = getTest().getContainer() }
 }
 
 /**

javascript/ql/src/semmle/javascript/Classes.qll

@@ -42,9 +42,6 @@ class ClassOrInterface extends @classorinterface, TypeParameterized {
     result = getIdentifier().getName() // Overridden in ClassExpr
   }
 
-  /** Gets the nearest enclosing function or toplevel in which this class or interface occurs. */
-  StmtContainer getContainer() { result = this.(ExprOrStmt).getContainer() }
-
   /** Gets a member declared in this class or interface. */
   MemberDeclaration getAMember() { result.getDeclaringType() = this }
 
@@ -278,9 +275,6 @@ class ClassDefinition extends @classdefinition, ClassOrInterface, AST::ValueNode
  * ```
  */
 class ClassDeclStmt extends @classdeclstmt, ClassDefinition, Stmt {
-  /** Gets the nearest enclosing function or toplevel in which this class declaration occurs. */
-  override StmtContainer getContainer() { result = Stmt.super.getContainer() }
-
   override ControlFlowNode getFirstControlFlowNode() {
     if hasDeclareKeyword(this) then result = this else result = getIdentifier()
   }
@@ -323,9 +317,6 @@ class ClassExpr extends @classexpr, ClassDefinition, Expr {
 
   override predicate isImpure() { none() }
 
-  /** Gets the nearest enclosing function or toplevel in which this class expression occurs. */
-  override StmtContainer getContainer() { result = Expr.super.getContainer() }
-
   override ControlFlowNode getFirstControlFlowNode() {
     if exists(getIdentifier())
     then result = getIdentifier()
@@ -545,9 +536,6 @@ class MemberDeclaration extends @property, Documentable {
   /** Gets the index of this member within its enclosing type. */
   int getMemberIndex() { properties(this, _, result, _, _) }
 
-  /** Gets the nearest enclosing function or toplevel in which this member occurs. */
-  StmtContainer getContainer() { result = getDeclaringType().getContainer() }
-
   /** Holds if the name of this member is computed by an impure expression. */
   predicate hasImpureNameExpr() { isComputed() and getNameExpr().isImpure() }
 

javascript/ql/src/semmle/javascript/Expr.qll

@@ -21,12 +21,6 @@ class ExprOrType extends @exprortype, Documentable {
   /** Gets the function in which this expression or type appears, if any. */
   Function getEnclosingFunction() { result = getContainer() }
 
-  /**
-   * Gets the statement container (function or toplevel) in which
-   * this expression or type appears.
-   */
-  StmtContainer getContainer() { exprContainers(this, result) }
-
   /**
    * Gets the JSDoc comment associated with this expression or type or its parent statement, if any.
    */
@@ -107,12 +101,6 @@ class ExprOrType extends @exprortype, Documentable {
  * ```
  */
 class Expr extends @expr, ExprOrStmt, ExprOrType, AST::ValueNode {
-  /**
-   * Gets the statement container (function or toplevel) in which
-   * this expression appears.
-   */
-  override StmtContainer getContainer() { exprContainers(this, result) }
-
   /** Gets this expression, with any surrounding parentheses removed. */
   override Expr stripParens() { result = this }
 
@@ -633,9 +621,6 @@ class Property extends @property, Documentable {
   /** Gets the (0-based) index at which this property appears in its enclosing literal. */
   int getIndex() { this = getObjectExpr().getProperty(result) }
 
-  /** Gets the function or toplevel in which this property occurs. */
-  StmtContainer getContainer() { result = getObjectExpr().getContainer() }
-
   /**
    * Holds if this property is impure, that is, the evaluation of its name or
    * its initializer expression could have side effects.

javascript/ql/src/semmle/javascript/JSDoc.qll

@@ -191,8 +191,6 @@ class JSDocTypeExpr extends @jsdoc_type_expr, JSDocTypeExprParent, TypeAnnotatio
     )
   }
 
-  override StmtContainer getContainer() { result = getEnclosingStmt().getContainer() }
-
   override Function getEnclosingFunction() { result = getContainer() }
 
   override TopLevel getTopLevel() { result = getEnclosingStmt().getTopLevel() }

javascript/ql/src/semmle/javascript/Stmt.qll

@@ -18,9 +18,6 @@ import javascript
  * ```
  */
 class Stmt extends @stmt, ExprOrStmt, Documentable {
-  /** Gets the statement container (toplevel, function or namespace) to which this statement belongs. */
-  override StmtContainer getContainer() { stmtContainers(this, result) }
-
   /** Holds if this statement has an implicitly inserted semicolon. */
   predicate hasSemicolonInserted() {
     isSubjectToSemicolonInsertion() and

javascript/ql/src/semmle/javascript/TypeAnnotations.qll

@@ -3,11 +3,12 @@
  */
 
 import javascript
+private import internal.StmtContainers
 
 /**
  * A type annotation, either in the form of a TypeScript type or a JSDoc comment.
  */
-class TypeAnnotation extends @type_annotation, Locatable {
+class TypeAnnotation extends @type_annotation, NodeInStmtContainer {
   /** Holds if this is the `any` type. */
   predicate isAny() { none() }
 
@@ -89,11 +90,6 @@ class TypeAnnotation extends @type_annotation, Locatable {
   /** Gets the function in which this type appears, if any. */
   Function getEnclosingFunction() { none() }
 
-  /**
-   * Gets the statement container (function or toplevel) in which this type appears.
-   */
-  StmtContainer getContainer() { none() }
-
   /**
    * Gets the top-level containing this type annotation.
    */

javascript/ql/src/semmle/javascript/TypeScript.qll

@@ -276,8 +276,6 @@ class InterfaceDeclaration extends Stmt, InterfaceDefinition, @interfacedeclarat
     )
   }
 
-  override StmtContainer getContainer() { result = Stmt.super.getContainer() }
-
   override string describe() { result = "interface " + getName() }
 
   /**
@@ -299,8 +297,6 @@ class InterfaceDeclaration extends Stmt, InterfaceDefinition, @interfacedeclarat
 class InterfaceTypeExpr extends TypeExpr, InterfaceDefinition, @interfacetypeexpr {
   override Identifier getIdentifier() { none() }
 
-  override StmtContainer getContainer() { result = TypeExpr.super.getContainer() }
-
   override string describe() { result = "anonymous interface" }
 }
 
@@ -535,8 +531,6 @@ class TypeExpr extends ExprOrType, @typeexpr, TypeAnnotation {
 
   override Function getEnclosingFunction() { result = ExprOrType.super.getEnclosingFunction() }
 
-  override StmtContainer getContainer() { result = ExprOrType.super.getContainer() }
-
   override TopLevel getTopLevel() { result = ExprOrType.super.getTopLevel() }
 
   override DataFlow::ClassNode getClass() { result.getAstNode() = getType().(ClassType).getClass() }

javascript/ql/src/semmle/javascript/Variables.qll

@@ -600,9 +600,6 @@ class PropertyPattern extends @property, ASTNode {
   /** Gets the object pattern this property pattern belongs to. */
   ObjectPattern getObjectPattern() { properties(this, result, _, _, _) }
 
-  /** Gets the nearest enclosing function or toplevel in which this property pattern occurs. */
-  StmtContainer getContainer() { result = getObjectPattern().getContainer() }
-
   /** Holds if this pattern is impure, that is, if its evaluation could have side effects. */
   predicate isImpure() {
     isComputed() and getNameExpr().isImpure()

javascript/ql/src/semmle/javascript/internal/StmtContainers.qll

@@ -0,0 +1,52 @@
+/**
+ * INTERNAL. DO NOT IMPORT DIRECTLY.
+ *
+ * Provides predicates and classes for relating nodes to their
+ * enclosing `StmtContainer`.
+ */
+private import javascript
+
+cached
+private StmtContainer getStmtContainer(@node_in_stmt_container node) {
+  exprContainers(node, result)
+  or
+  stmtContainers(node, result)
+  or
+  // Properties
+  exists(ASTNode parent |
+    properties(node, parent, _, _, _)
+  |
+    exprContainers(parent, result)
+    or
+    stmtContainers(parent, result)
+  )
+  or
+  // Synthetic CFG nodes
+  entry_cfg_node(node, result)
+  or
+  exit_cfg_node(node, result)
+  or
+  exists(Expr test |
+    guard_node(node, _, test) and
+    exprContainers(test, result)
+  )
+  or
+  // JSDoc type annotations
+  stmtContainers(node.(JSDocTypeExpr).getEnclosingStmt(), result)
+}
+
+/**
+ * A node that occurs inside a function or top-level or is itself a top-level.
+ *
+ * Specifically, this is the union type of `ControlFlowNode`, `TypeAnnotation`,
+ * and `TopLevel`.
+ */
+class NodeInStmtContainer extends Locatable, @node_in_stmt_container {
+  /**
+   * Gets the function or toplevel to which this node belongs.
+   */
+  pragma[inline]
+  final StmtContainer getContainer() {
+    result = getStmtContainer(this)
+  }
+}

javascript/ql/src/semmlecode.javascript.dbscheme

@@ -233,6 +233,7 @@ isDelegating (int yield: @yieldexpr ref);
 @exprparent = @exprorstmt | @property | @functiontypeexpr;
 @arraylike = @arrayexpr | @arraypattern;
 @type_annotation = @typeexpr | @jsdoc_type_expr;
+@node_in_stmt_container = @cfg_node | @type_annotation | @toplevel;
 
 case @expr.kind of
    0 = @label