AST: move some scope related methods to AstNode

ql/src/codeql_ruby/AST.qll

@@ -13,6 +13,7 @@ import ast.Scope
 import ast.Statement
 import ast.Variable
 private import ast.internal.AST
+private import ast.internal.Scope
 
 /**
  * A node in the abstract syntax tree. This class is the base class for all Ruby
@@ -28,6 +29,20 @@ class AstNode extends TAstNode {
    */
   string getAPrimaryQlClass() { result = "???" }
 
+  /** Gets the enclosing module, if any. */
+  ModuleBase getEnclosingModule() {
+    exists(Scope::Range s |
+      s = scopeOf(toGenerated(this)) and toGenerated(result) = s.getEnclosingModule()
+    )
+  }
+
+  /** Gets the enclosing method, if any. */
+  MethodBase getEnclosingMethod() {
+    exists(Scope::Range s |
+      s = scopeOf(toGenerated(this)) and toGenerated(result) = s.getEnclosingMethod()
+    )
+  }
+
   /** Gets a textual representation of this node. */
   cached
   string toString() { none() }

ql/src/codeql_ruby/ast/Scope.qll

@@ -8,18 +8,9 @@ class Scope extends AstNode, TScopeType {
 
   Scope() { range = toGenerated(this) }
 
-  /** Gets the enclosing module, if any. */
-  ModuleBase getEnclosingModule() { toGenerated(result) = range.getEnclosingModule() }
-
-  /** Gets the enclosing method, if any. */
-  MethodBase getEnclosingMethod() { toGenerated(result) = range.getEnclosingMethod() }
-
   /** Gets the scope in which this scope is nested, if any. */
   Scope getOuterScope() { toGenerated(result) = range.getOuterScope() }
 
-  /** Gets the scope in which this scope is nested, if any. */
-  AstNode getADescendant() { range = scopeOf(toGenerated(result)) }
-
   /** Gets a variable that is declared in this scope. */
   final Variable getAVariable() { result.getDeclaringScope() = this }
 

ql/src/codeql_ruby/ast/internal/Module.qll

@@ -23,7 +23,7 @@ private predicate isToplevel(ConstantAccess n) {
   (
     n.hasGlobalScope()
     or
-    exists(Scope x | x.getADescendant() = n and x.getEnclosingModule() instanceof Toplevel)
+    n.getEnclosingModule() instanceof Toplevel
   )
 }
 
@@ -48,7 +48,7 @@ private string resolveScopeExpr0(ConstantReadAccess n) {
 ModuleBase enclosing(ModuleBase m, int level) {
   result = m and level = 0
   or
-  result = enclosing(m.getOuterScope().getEnclosingModule(), level - 1)
+  result = enclosing(m.getEnclosingModule(), level - 1)
 }
 
 bindingset[qualifier, name]
@@ -59,9 +59,8 @@ private string scopeAppend(string qualifier, string name) {
 private string resolveRelativeToEnclosing(ConstantAccess n, int i) {
   not isToplevel(n) and
   not exists(n.getScopeExpr()) and
-  exists(Scope s, ModuleBase enclosing |
-    n = s.getADescendant() and
-    enclosing = enclosing(s.getEnclosingModule(), i) and
+  exists(ModuleBase enclosing |
+    enclosing = enclosing(n.getEnclosingModule(), i) and
     result = scopeAppend(constantDefinition0(enclosing), n.getName()) and
     (result = builtin() or result = constantDefinition0(_) or n instanceof ConstantWriteAccess)
   )
@@ -75,12 +74,12 @@ private class IncludeOrPrependCall extends MethodCall {
   string getTarget() {
     result = resolveScopeExpr0(this.getReceiver())
     or
-    exists(Scope s |
-      s.getADescendant() = this and
+    exists(ModuleBase enclosing |
+      enclosing = this.getEnclosingModule() and
       (
-        result = constantDefinition0(s.getEnclosingModule())
+        result = constantDefinition0(enclosing)
         or
-        result = "Object" and s.getEnclosingModule() instanceof Toplevel
+        result = "Object" and enclosing instanceof Toplevel
       )
     |
       this.getReceiver() instanceof Self
@@ -171,10 +170,7 @@ private string containsIgnoringSuper(string qname, string name) {
 private string resolveRelativeToAncestors(ConstantReadAccess n) {
   not isToplevel(n) and
   not exists(n.getScopeExpr()) and
-  exists(Scope s, ModuleBase enclosing |
-    n = s.getADescendant() and
-    enclosing = s.getEnclosingModule()
-  |
+  exists(ModuleBase enclosing | enclosing = n.getEnclosingModule() |
     result = contains(constantDefinition(enclosing), n.getName())
     or
     enclosing instanceof Toplevel and result = contains("Object", n.getName())