Merge pull request #58 from github/hvitved/pattern-get-a-variable

Add `Pattern::getAVariable()` and use `self` range field throughout

ql/src/codeql_ruby/ast/Method.qll

@@ -4,7 +4,9 @@ private import internal.Method
 
 /** A callable. */
 class Callable extends AstNode {
-  Callable() { this instanceof CallableRange }
+  Callable::Range range;
+
+  Callable() { range = this }
 
   /** Gets the number of parameters of this callable. */
   final int getNumberOfParameters() { result = count(this.getAParameter()) }
@@ -12,12 +14,13 @@ class Callable extends AstNode {
   /** Gets a parameter of this callable. */
   final Parameter getAParameter() { result = this.getParameter(_) }
 
-  /** Gets the nth parameter of this callable. */
-  final Parameter getParameter(int n) { result = this.(CallableRange).getParameter(n) }
+  /** Gets the `n`th parameter of this callable. */
+  final Parameter getParameter(int n) { result = range.getParameter(n) }
 }
 
 /** A method. */
 class Method extends Callable, @method {
+  final override Method::Range range;
   final override Generated::Method generated;
 
   final override string describeQlClass() { result = "Method" }
@@ -25,12 +28,7 @@ class Method extends Callable, @method {
   final override string toString() { result = this.getName() }
 
   /** Gets the name of this method. */
-  final string getName() {
-    result = generated.getName().(Generated::Token).getValue() or
-    // TODO: use hand-written Symbol class
-    result = generated.getName().(Generated::Symbol).toString() or
-    result = generated.getName().(Generated::Setter).getName().getValue() + "="
-  }
+  final string getName() { result = range.getName() }
 
   /**
    * Holds if this is a setter method, as in the following example:
@@ -47,19 +45,14 @@ class Method extends Callable, @method {
 
 /** A singleton method. */
 class SingletonMethod extends Callable, @singleton_method {
-  final override Generated::SingletonMethod generated;
+  final override SingletonMethod::Range range;
 
   final override string describeQlClass() { result = "SingletonMethod" }
 
   final override string toString() { result = this.getName() }
 
   /** Gets the name of this method. */
-  final string getName() {
-    result = generated.getName().(Generated::Token).getValue() or
-    // TODO: use hand-written Symbol class
-    result = generated.getName().(Generated::Symbol).toString() or
-    result = generated.getName().(Generated::Setter).getName().getValue() + "="
-  }
+  final string getName() { result = range.getName() }
 }
 
 /**
@@ -69,7 +62,7 @@ class SingletonMethod extends Callable, @singleton_method {
  * ```
  */
 class Lambda extends Callable, @lambda {
-  final override Generated::Lambda generated;
+  final override Lambda::Range range;
 
   final override string describeQlClass() { result = "Lambda" }
 
@@ -78,12 +71,12 @@ class Lambda extends Callable, @lambda {
 
 /** A block. */
 class Block extends AstNode, Callable {
-  Block() { this instanceof BlockRange }
+  override Block::Range range;
 }
 
 /** A block enclosed within `do` and `end`. */
 class DoBlock extends Block, @do_block {
-  final override Generated::DoBlock generated;
+  final override DoBlock::Range range;
 
   final override string describeQlClass() { result = "DoBlock" }
 
@@ -97,7 +90,7 @@ class DoBlock extends Block, @do_block {
  * ```
  */
 class BraceBlock extends Block, @block {
-  final override Generated::Block generated;
+  final override BraceBlock::Range range;
 
   final override string describeQlClass() { result = "BraceBlock" }
 

ql/src/codeql_ruby/ast/Parameter.qll

@@ -1,6 +1,5 @@
 import codeql_ruby.AST
-private import Variable
-private import Pattern
+private import internal.Pattern
 private import internal.TreeSitter
 private import internal.Variable
 
@@ -37,15 +36,13 @@ class Parameter extends AstNode {
  *
  * This includes both simple parameters and tuple parameters.
  */
-class PatternParameter extends Parameter, Pattern { }
+class PatternParameter extends Parameter, Pattern {
+  override Variable getAVariable() { result = Pattern.super.getAVariable() }
+}
 
 /** A parameter defined using a tuple pattern. */
 class TuplePatternParameter extends PatternParameter, TuplePattern {
   final override string describeQlClass() { result = "TuplePatternParameter" }
-
-  final override Variable getAVariable() {
-    result = this.getAnElement+().(VariablePattern).getVariable()
-  }
 }
 
 /** A named parameter. */
@@ -58,7 +55,7 @@ class NamedParameter extends Parameter {
   /** Gets the variable introduced by this parameter. */
   Variable getVariable() { none() }
 
-  final override Variable getAVariable() { result = this.getVariable() }
+  override Variable getAVariable() { result = this.getVariable() }
 
   /** Gets an access to this parameter. */
   final VariableAccess getAnAccess() { result = this.getVariable().getAnAccess() }
@@ -66,10 +63,12 @@ class NamedParameter extends Parameter {
 
 /** A simple (normal) parameter. */
 class SimpleParameter extends NamedParameter, PatternParameter, VariablePattern {
-  final override string getName() { result = this.getVariableName() }
+  final override string getName() { result = range.getVariableName() }
 
   final override Variable getVariable() { result = TLocalVariable(_, _, this) }
 
+  final override Variable getAVariable() { result = this.getVariable() }
+
   final override string describeQlClass() { result = "SimpleParameter" }
 
   final override string toString() { result = this.getName() }

ql/src/codeql_ruby/ast/Pattern.qll

@@ -7,20 +7,23 @@ private import Variable
 
 /** A pattern. */
 class Pattern extends AstNode {
-  Pattern() { this instanceof PatternRange }
+  Pattern::Range range;
+
+  Pattern() { range = this }
+
+  /** Gets a variable used in (or introduced by) this pattern. */
+  Variable getAVariable() { result = range.getAVariable() }
 }
 
 /** A simple variable pattern. */
 class VariablePattern extends Pattern {
+  final override VariablePattern::Range range;
   final override Generated::Identifier generated;
 
-  /** Gets the name of the variable used in this pattern. */
-  final string getVariableName() { result = generated.getValue() }
-
   /** Gets the variable used in (or introduced by) this pattern. */
   Variable getVariable() { access(this, result) }
 
-  override string toString() { result = this.getVariableName() }
+  override string toString() { result = range.getVariableName() }
 }
 
 /**
@@ -29,10 +32,10 @@ class VariablePattern extends Pattern {
  * This includes both tuple patterns in parameters and assignments.
  */
 class TuplePattern extends Pattern {
-  TuplePattern() { this instanceof TuplePatternRange }
+  final override TuplePattern::Range range;
 
   /** Gets the `i`th pattern in this tuple pattern. */
-  final Pattern getElement(int i) { result = this.(TuplePatternRange).getElement(i) }
+  final Pattern getElement(int i) { result = range.getElement(i) }
 
   /** Gets a sub pattern in this tuple pattern. */
   final Pattern getAnElement() { result = this.getElement(_) }

ql/src/codeql_ruby/ast/Variable.qll

@@ -7,11 +7,15 @@ private import internal.Variable
 
 /** A scope in which variables can be declared. */
 class VariableScope extends TScope {
+  VariableScope::Range range;
+
+  VariableScope() { range = this }
+
   /** Gets a textual representation of this element. */
-  final string toString() { result = this.(VariableScopeRange).toString() }
+  final string toString() { result = range.toString() }
 
   /** Gets the program element this scope is associated with, if any. */
-  final AstNode getScopeElement() { result = this.(VariableScopeRange).getScopeElement() }
+  final AstNode getScopeElement() { result = range.getScopeElement() }
 
   /** Gets the location of the program element this scope is associated with. */
   final Location getLocation() { result = getScopeElement().getLocation() }
@@ -28,17 +32,21 @@ class VariableScope extends TScope {
 
 /** A variable declared in a scope. */
 class Variable extends TVariable {
+  Variable::Range range;
+
+  Variable() { range = this }
+
   /** Gets the name of this variable. */
-  final string getName() { result = this.(VariableRange).getName() }
+  final string getName() { result = range.getName() }
 
   /** Gets a textual representation of this variable. */
   final string toString() { result = this.getName() }
 
   /** Gets the location of this variable. */
-  final Location getLocation() { result = this.(VariableRange).getLocation() }
+  final Location getLocation() { result = range.getLocation() }
 
   /** Gets the scope this variable is declared in. */
-  final VariableScope getDeclaringScope() { result = this.(VariableRange).getDeclaringScope() }
+  final VariableScope getDeclaringScope() { result = range.getDeclaringScope() }
 
   /** Gets an access to this variable. */
   VariableAccess getAnAccess() { result.getVariable() = this }
@@ -46,11 +54,7 @@ class Variable extends TVariable {
 
 /** A local variable. */
 class LocalVariable extends Variable {
-  private VariableScope scope;
-  private string name;
-  private Generated::Identifier i;
-
-  LocalVariable() { this = TLocalVariable(scope, name, i) }
+  override LocalVariable::Range range;
 
   final override LocalVariableAccess getAnAccess() { result.getVariable() = this }
 }

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

@@ -1,42 +1,70 @@
 import codeql_ruby.AST
 private import TreeSitter
 
-abstract class CallableRange extends AstNode {
-  abstract Parameter getParameter(int n);
+module Callable {
+  abstract class Range extends AstNode {
+    abstract Parameter getParameter(int n);
+  }
 }
 
-private class MethodRange extends CallableRange, @method {
-  final override Generated::Method generated;
+module Method {
+  class Range extends Callable::Range, @method {
+    final override Generated::Method generated;
 
-  override Parameter getParameter(int n) { result = generated.getParameters().getChild(n) }
+    override Parameter getParameter(int n) { result = generated.getParameters().getChild(n) }
+
+    string getName() {
+      result = generated.getName().(Generated::Token).getValue() or
+      // TODO: use hand-written Symbol class
+      result = generated.getName().(Generated::Symbol).toString() or
+      result = generated.getName().(Generated::Setter).getName().getValue() + "="
+    }
+  }
 }
 
-private class SingletonMethodRange extends CallableRange, @singleton_method {
-  final override Generated::SingletonMethod generated;
+module SingletonMethod {
+  class Range extends Callable::Range, @singleton_method {
+    final override Generated::SingletonMethod generated;
 
-  override Parameter getParameter(int n) { result = generated.getParameters().getChild(n) }
+    override Parameter getParameter(int n) { result = generated.getParameters().getChild(n) }
+
+    string getName() {
+      result = generated.getName().(Generated::Token).getValue() or
+      // TODO: use hand-written Symbol class
+      result = generated.getName().(Generated::Symbol).toString() or
+      result = generated.getName().(Generated::Setter).getName().getValue() + "="
+    }
+  }
 }
 
-private class LambdaRange extends CallableRange, @lambda {
-  final override Generated::Lambda generated;
+module Lambda {
+  class Range extends Callable::Range, @lambda {
+    final override Generated::Lambda generated;
 
-  final override Parameter getParameter(int n) { result = generated.getParameters().getChild(n) }
+    final override Parameter getParameter(int n) { result = generated.getParameters().getChild(n) }
+  }
 }
 
-abstract class BlockRange extends CallableRange {
-  Generated::BlockParameters params;
+module Block {
+  abstract class Range extends Callable::Range {
+    Generated::BlockParameters params;
 
-  final override Parameter getParameter(int n) { result = params.getChild(n) }
+    final override Parameter getParameter(int n) { result = params.getChild(n) }
+  }
 }
 
-private class DoBlockRange extends BlockRange, @do_block {
-  final override Generated::DoBlock generated;
+module DoBlock {
+  class Range extends Block::Range, @do_block {
+    final override Generated::DoBlock generated;
 
-  DoBlockRange() { params = generated.getParameters() }
+    Range() { params = generated.getParameters() }
+  }
 }
 
-private class BraceBlockRange extends BlockRange, @block {
-  final override Generated::Block generated;
+module BraceBlock {
+  class Range extends Block::Range, @block {
+    final override Generated::Block generated;
 
-  BraceBlockRange() { params = generated.getParameters() }
+    Range() { params = generated.getParameters() }
+  }
 }

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

@@ -1,5 +1,6 @@
 import codeql_ruby.AST
 private import TreeSitter
+private import Variable
 private import codeql.Locations
 
 private predicate tuplePatternNode(Generated::AstNode n, boolean parameter) {
@@ -34,32 +35,46 @@ private predicate patternNode(Generated::AstNode n, boolean parameter) {
  */
 predicate assignment(Generated::Identifier i, boolean parameter) { patternNode(i, parameter) }
 
-abstract class PatternRange extends AstNode {
-  PatternRange() { patternNode(this, _) }
+module Pattern {
+  abstract class Range extends AstNode {
+    Range() { patternNode(this, _) }
+
+    abstract Variable getAVariable();
+  }
 }
 
-private class VariablePatternRange extends PatternRange {
-  override Generated::Identifier generated;
+module VariablePattern {
+  class Range extends Pattern::Range {
+    override Generated::Identifier generated;
+
+    string getVariableName() { result = generated.getValue() }
+
+    override Variable getAVariable() { access(this, result) }
+  }
 }
 
-abstract class TuplePatternRange extends PatternRange {
-  abstract Pattern getElement(int i);
-}
-
-private class ParameterTuplePatternRange extends TuplePatternRange {
-  override Generated::DestructuredParameter generated;
-
-  override Pattern getElement(int i) { result = generated.getChild(i) }
-}
-
-private class AssignmentTuplePatternRange extends TuplePatternRange {
-  override Generated::DestructuredLeftAssignment generated;
-
-  override Pattern getElement(int i) { result = generated.getChild(i) }
-}
-
-private class AssignmentListPatternRange extends TuplePatternRange {
-  override Generated::LeftAssignmentList generated;
-
-  override Pattern getElement(int i) { result = generated.getChild(i) }
+module TuplePattern {
+  abstract class Range extends Pattern::Range {
+    abstract Pattern::Range getElement(int i);
+
+    override Variable getAVariable() { result = this.getElement(_).getAVariable() }
+  }
+
+  private class ParameterTuplePatternRange extends Range {
+    override Generated::DestructuredParameter generated;
+
+    override Pattern::Range getElement(int i) { result = generated.getChild(i) }
+  }
+
+  private class AssignmentTuplePatternRange extends Range {
+    override Generated::DestructuredLeftAssignment generated;
+
+    override Pattern::Range getElement(int i) { result = generated.getChild(i) }
+  }
+
+  private class AssignmentListPatternRange extends Range {
+    override Generated::LeftAssignmentList generated;
+
+    override Pattern::Range getElement(int i) { result = generated.getChild(i) }
+  }
 }

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

@@ -13,7 +13,9 @@ private VariableScope enclosingScope(Generated::AstNode node) {
   result.getScopeElement() = parent*(node.getParent())
 }
 
-private predicate parameterAssignment(CallableScopeRange scope, string name, Generated::Identifier i) {
+private predicate parameterAssignment(
+  CallableScope::Range scope, string name, Generated::Identifier i
+) {
   assignment(i, true) and
   scope = enclosingScope(i) and
   name = i.getValue()
@@ -21,7 +23,7 @@ private predicate parameterAssignment(CallableScopeRange scope, string name, Gen
 
 /** Holds if `scope` defines `name` in its parameter declaration at `i`. */
 private predicate scopeDefinesParameterVariable(
-  CallableScopeRange scope, string name, Generated::Identifier i
+  CallableScope::Range scope, string name, Generated::Identifier i
 ) {
   parameterAssignment(scope, name, i) and
   // In case of overlapping parameter names (e.g. `_`), only the first
@@ -142,69 +144,83 @@ private module Cached {
 
 import Cached
 
-abstract class VariableScopeRange extends TScope {
-  abstract string toString();
+module VariableScope {
+  abstract class Range extends TScope {
+    abstract string toString();
 
-  abstract AstNode getScopeElement();
-}
-
-class TopLevelScopeRange extends VariableScopeRange, TTopLevelScope {
-  override string toString() { result = "top-level scope" }
-
-  override AstNode getScopeElement() { TTopLevelScope(result) = this }
-}
-
-class ModuleScopeRange extends VariableScopeRange, TModuleScope {
-  override string toString() { result = "module scope" }
-
-  override AstNode getScopeElement() { TModuleScope(result) = this }
-}
-
-class ClassScopeRange extends VariableScopeRange, TClassScope {
-  override string toString() { result = "class scope" }
-
-  override AstNode getScopeElement() { TClassScope(result) = this }
-}
-
-class CallableScopeRange extends VariableScopeRange, TCallableScope {
-  private Callable c;
-
-  CallableScopeRange() { this = TCallableScope(c) }
-
-  override string toString() {
-    (c instanceof Method or c instanceof SingletonMethod) and
-    result = "method scope"
-    or
-    c instanceof Lambda and
-    result = "lambda scope"
-    or
-    c instanceof Block and
-    result = "block scope"
+    abstract AstNode getScopeElement();
   }
-
-  override Callable getScopeElement() { TCallableScope(result) = this }
 }
 
-class VariableRange extends TVariable {
-  abstract string getName();
+module TopLevelScope {
+  class Range extends VariableScope::Range, TTopLevelScope {
+    override string toString() { result = "top-level scope" }
 
-  string toString() { result = this.getName() }
-
-  abstract Location getLocation();
-
-  abstract VariableScope getDeclaringScope();
+    override AstNode getScopeElement() { TTopLevelScope(result) = this }
+  }
 }
 
-class LocalVariableRange extends VariableRange {
-  private VariableScope scope;
-  private string name;
-  private Generated::Identifier i;
+module ModuleScope {
+  class Range extends VariableScope::Range, TModuleScope {
+    override string toString() { result = "module scope" }
 
-  LocalVariableRange() { this = TLocalVariable(scope, name, i) }
-
-  final override string getName() { result = name }
-
-  final override Location getLocation() { result = i.getLocation() }
-
-  final override VariableScope getDeclaringScope() { result = scope }
+    override AstNode getScopeElement() { TModuleScope(result) = this }
+  }
+}
+
+module ClassScope {
+  class Range extends VariableScope::Range, TClassScope {
+    override string toString() { result = "class scope" }
+
+    override AstNode getScopeElement() { TClassScope(result) = this }
+  }
+}
+
+module CallableScope {
+  class Range extends VariableScope::Range, TCallableScope {
+    private Callable c;
+
+    Range() { this = TCallableScope(c) }
+
+    override string toString() {
+      (c instanceof Method or c instanceof SingletonMethod) and
+      result = "method scope"
+      or
+      c instanceof Lambda and
+      result = "lambda scope"
+      or
+      c instanceof Block and
+      result = "block scope"
+    }
+
+    override Callable getScopeElement() { TCallableScope(result) = this }
+  }
+}
+
+module Variable {
+  class Range extends TVariable {
+    abstract string getName();
+
+    string toString() { result = this.getName() }
+
+    abstract Location getLocation();
+
+    abstract VariableScope getDeclaringScope();
+  }
+}
+
+module LocalVariable {
+  class Range extends Variable::Range {
+    private VariableScope scope;
+    private string name;
+    private Generated::Identifier i;
+
+    Range() { this = TLocalVariable(scope, name, i) }
+
+    final override string getName() { result = name }
+
+    final override Location getLocation() { result = i.getLocation() }
+
+    final override VariableScope getDeclaringScope() { result = scope }
+  }
 }