Merge pull request #424 from esben-semmle/js/syntactic-nullOrUndefined

Approved by asger-semmle

javascript/ql/src/Declarations/BuiltinRedefined.ql

@@ -27,12 +27,12 @@ predicate acceptableRedefinition(Identifier id) {
   // Date = global.Date
   exists (AssignExpr assgn |
     id = assgn.getTarget() and
-    id.getName() = assgn.getRhs().stripParens().(PropAccess).getPropertyName()
+    id.getName() = assgn.getRhs().getUnderlyingValue().(PropAccess).getPropertyName()
   ) or
   // var Date = global.Date
   exists (VariableDeclarator decl |
     id = decl.getBindingPattern() and
-    id.getName() = decl.getInit().stripParens().(PropAccess).getPropertyName()
+    id.getName() = decl.getInit().getUnderlyingValue().(PropAccess).getPropertyName()
   )
 }
 

javascript/ql/src/Declarations/UnusedParameter.qll

@@ -10,7 +10,7 @@ import javascript
  * Holds if `e` is an expression whose value is invoked as a function.
  */
 private predicate isCallee(Expr e) {
-  exists (InvokeExpr invk | e = invk.getCallee().stripParens())
+  exists (InvokeExpr invk | e = invk.getCallee().getUnderlyingValue())
 }
 
 /**

javascript/ql/src/Expressions/BadParityCheck.ql

@@ -65,7 +65,7 @@ predicate maybeNegativeVar(Variable v) {
   // is v ever assigned a potentially negative value?
   maybeNegative(v.getAnAssignedExpr()) or
   // is v ever decremented?
-  exists (DecExpr dec | dec.getOperand().stripParens() = v.getAnAccess()) or
+  exists (DecExpr dec | dec.getOperand().getUnderlyingReference() = v.getAnAccess()) or
   // is v ever subject to a compound assignment other than +=, or to
   // += with potentially negative rhs?
   exists (CompoundAssignExpr assgn | assgn.getTarget() = v.getAnAccess() |

javascript/ql/src/Expressions/BitwiseSignCheck.ql

@@ -37,13 +37,13 @@ predicate acceptableSignCheck(BitwiseExpr b) {
    * is sign-preserving, we shouldn't flag it (and we allow arbitrary shifts, not just 16-bit ones)
    */
   exists (RShiftExpr rsh, LShiftExpr lsh |
-    rsh = b and lsh = rsh.getLeftOperand().stripParens() and
+    rsh = b and lsh = rsh.getLeftOperand().getUnderlyingValue() and
     lsh.getRightOperand().getIntValue() = rsh.getRightOperand().getIntValue()
   )
 }
 
 from Comparison e, BitwiseExpr b
-where b = e.getLeftOperand().stripParens() and
+where b = e.getLeftOperand().getUnderlyingValue() and
       not e instanceof EqualityTest and
       e.getRightOperand().getIntValue() = 0 and
       not acceptableSignCheck(b)

javascript/ql/src/Expressions/RedundantExpression.ql

@@ -58,7 +58,7 @@ class RedundantIdemnecantOperand extends RedundantOperand {
     exists (IdemnecantExpr parent |
       parent = getParent() and
       // exclude trivial cases like `1-1`
-      not parent.getRightOperand().stripParens() instanceof Literal
+      not parent.getRightOperand().getUnderlyingValue() instanceof Literal
     )
   }
 }
@@ -80,7 +80,7 @@ class RedundantIdempotentOperand extends RedundantOperand {
  */
 class AverageExpr extends DivExpr {
   AverageExpr() {
-    getLeftOperand().stripParens() instanceof AddExpr and
+    getLeftOperand().getUnderlyingValue() instanceof AddExpr and
     getRightOperand().getIntValue() = 2
   }
 }
@@ -91,12 +91,12 @@ class AverageExpr extends DivExpr {
 class RedundantAverageOperand extends RedundantOperand {
   RedundantAverageOperand() {
     exists (AverageExpr aver |
-      (AddExpr)getParent() = aver.getLeftOperand().stripParens()
+      (AddExpr)getParent() = aver.getLeftOperand().getUnderlyingValue()
     )
   }
 
   override AverageExpr toReport() {
-    getParent() = result.getLeftOperand().stripParens()
+    getParent() = result.getLeftOperand().getUnderlyingValue()
   }
 }
 

javascript/ql/src/LanguageFeatures/BadTypeof.ql

@@ -47,7 +47,7 @@ class EqOrSwitch extends ASTNode {
 }
 
 from EqOrSwitch et, TypeofExpr typeof, ConstantString str
-where typeof = et.getAnOperand().stripParens() and
-      str = et.getAnOperand().stripParens() and
+where typeof = et.getAnOperand().getUnderlyingValue() and
+      str = et.getAnOperand().getUnderlyingValue() and
       not str.getStringValue().regexpMatch("undefined|boolean|number|string|object|function|symbol|unknown|date|bigint")
 select typeof, "The result of this 'typeof' expression is compared to '$@', but the two can never be equal.", str, str.getStringValue()

javascript/ql/src/Statements/ImplicitReturn.ql

@@ -56,7 +56,7 @@ int numRet(Function f) {
 predicate isDualUseConstructor(Function f) {
   numRet(f) = 1 and
   exists (ReturnStmt ret, DataFlow::NewNode new | ret.getContainer() = f |
-    new.asExpr() = ret.getExpr().stripParens() and
+    new.asExpr() = ret.getExpr().getUnderlyingValue() and
     new.getACallee() = f
   )
 }

javascript/ql/src/Statements/SuspiciousUnusedLoopIterationVariable.ql

@@ -26,7 +26,7 @@ class IncrementExpr extends Expr {
     // x = x + e
     exists (AssignExpr assgn, Variable v | assgn = this |
       assgn.getTarget() = v.getAnAccess() and
-      assgn.getRhs().(AddExpr).getAnOperand().stripParens() = v.getAnAccess()
+      assgn.getRhs().(AddExpr).getAnOperand().getUnderlyingReference() = v.getAnAccess()
     )
   }
 }

javascript/ql/src/Statements/UselessConditional.ql

@@ -28,13 +28,13 @@ import semmle.javascript.dataflow.Refinements
  */
 predicate isDefensiveInit(VarAccess va) {
   exists (LogOrExpr o, VarRef va2 |
-    va = o.getLeftOperand().stripParens() and va2.getVariable() = va.getVariable() |
+    va = o.getLeftOperand().getUnderlyingReference() and va2.getVariable() = va.getVariable() |
     exists (AssignExpr assgn | va2 = assgn.getTarget() |
       assgn = o.getRightOperand().stripParens() or
-      o = assgn.getRhs().stripParens()
+      o = assgn.getRhs().getUnderlyingValue()
     ) or
     exists (VariableDeclarator vd | va2 = vd.getBindingPattern() |
-      o = vd.getInit().stripParens()
+      o = vd.getInit().getUnderlyingValue()
     )
   )
 }

javascript/ql/src/definitions.ql

@@ -19,7 +19,7 @@ private import Declarations.Declarations
  * `x` has kind `"V"`.
  */
 string refKind(RefExpr r) {
-  if exists(InvokeExpr invk | r = invk.getCallee().stripParens()) then
+  if exists(InvokeExpr invk | r = invk.getCallee().getUnderlyingReference()) then
     result = "M"
   else
     result = "V"
@@ -143,7 +143,7 @@ predicate typedInvokeLookup(ASTNode ref, ASTNode decl, string kind) {
   not variableDefLookup(ref, decl, _) and
   not propertyLookup(ref, decl, _) and
   exists (InvokeExpr invoke, Expr callee | 
-    callee = invoke.getCallee().stripParens() and
+    callee = invoke.getCallee().getUnderlyingReference() and
     (ref = callee.(Identifier) or ref = callee.(DotExpr).getPropertyNameExpr()) and
     decl = invoke.getResolvedCallee() and
     kind = "M")

javascript/ql/src/semmle/javascript/AMD.qll

@@ -172,7 +172,7 @@ class AMDModuleDefinition extends CallExpr {
    * Gets a call to `require` inside this module.
    */
   CallExpr getARequireCall() {
-    result.getCallee().stripParens() = getRequireVariable().getAnAccess()
+    result.getCallee().getUnderlyingValue() = getRequireVariable().getAnAccess()
   }
 }
 

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

@@ -291,7 +291,7 @@ class SuperExpr extends @superexpr, Expr {
  */
 class SuperCall extends CallExpr {
   SuperCall() {
-    getCallee().stripParens() instanceof SuperExpr
+    getCallee().getUnderlyingValue() instanceof SuperExpr
   }
 
   /**
@@ -299,7 +299,7 @@ class SuperCall extends CallExpr {
    * which is the nearest enclosing non-arrow function.
    */
   Function getBinder() {
-    result = getCallee().stripParens().(SuperExpr).getBinder()
+    result = getCallee().getUnderlyingValue().(SuperExpr).getBinder()
   }
 }
 
@@ -308,7 +308,7 @@ class SuperCall extends CallExpr {
  */
 class SuperPropAccess extends PropAccess {
   SuperPropAccess() {
-    getBase().stripParens() instanceof SuperExpr
+    getBase().getUnderlyingValue() instanceof SuperExpr
   }
 }
 

javascript/ql/src/semmle/javascript/DefUse.qll

@@ -71,7 +71,7 @@ private predicate defn(ControlFlowNode def, Expr lhs, AST::ValueNode rhs) {
 private predicate defn(ControlFlowNode def, Expr lhs) {
   defn(def, lhs, _) or
   lhs = def.(CompoundAssignExpr).getTarget() or
-  lhs = def.(UpdateExpr).getOperand().stripParens() or
+  lhs = def.(UpdateExpr).getOperand().getUnderlyingReference() or
   lhs = def.(ImportSpecifier).getLocal() or
   exists (EnhancedForLoop efl | def = efl.getIteratorExpr() |
     lhs = def.(Expr).stripParens() or
@@ -143,7 +143,7 @@ class RValue extends RefExpr {
     not this instanceof LValue and not this instanceof VarDecl or
     // in `x++` and `x += 1`, `x` is both RValue and LValue
     this = any(CompoundAssignExpr a).getTarget() or
-    this = any(UpdateExpr u).getOperand().stripParens() or
+    this = any(UpdateExpr u).getOperand().getUnderlyingReference() or
     this = any(NamespaceDeclaration decl).getId()
   }
 }

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

@@ -710,7 +710,7 @@ class InvokeExpr extends @invokeexpr, Expr {
 
   /** Gets the name of the function or method being invoked, if it can be determined. */
   string getCalleeName() {
-    exists (Expr callee | callee = getCallee().stripParens() |
+    exists (Expr callee | callee = getCallee().getUnderlyingValue() |
       result = ((Identifier)callee).getName() or
       result = ((PropAccess)callee).getPropertyName()
     )
@@ -1690,10 +1690,10 @@ class ImmediatelyInvokedFunctionExpr extends Function {
 
   ImmediatelyInvokedFunctionExpr() {
     // direct call
-    this = invk.getCallee().stripParens() and kind = "direct" or
+    this = invk.getCallee().getUnderlyingValue() and kind = "direct" or
     // reflective call
     exists (MethodCallExpr mce | mce = invk |
-      this = mce.getReceiver().stripParens() and
+      this = mce.getReceiver().getUnderlyingValue() and
       kind = mce.getMethodName() and
       (kind = "call" or kind = "apply")
     )

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

@@ -319,7 +319,7 @@ class VarAccess extends @varaccess, VarRef, LexicalAccess {
 
   override predicate isLValue() {
     exists (Assignment assgn | assgn.getTarget() = this) or
-    exists (UpdateExpr upd | upd.getOperand().stripParens() = this) or
+    exists (UpdateExpr upd | upd.getOperand().getUnderlyingReference() = this) or
     exists (EnhancedForLoop efl | efl.getIterator() = this) or
     exists (BindingPattern p | this = p.getABindingVarRef() and p.isLValue())
   }

javascript/ql/src/semmle/javascript/dataflow/Sources.qll

@@ -125,7 +125,7 @@ abstract class SourceNode extends DataFlow::Node {
    */
   DataFlow::CallNode getAMethodCall(string methodName) {
     exists (PropAccess pacc |
-      pacc = result.getCalleeNode().asExpr().stripParens() and
+      pacc = result.getCalleeNode().asExpr().getUnderlyingReference() and
       flowsToExpr(pacc.getBase()) and
       pacc.getPropertyName() = methodName
     )

javascript/ql/src/semmle/javascript/dataflow/internal/BasicExprTypeInference.qll

@@ -159,7 +159,7 @@ private class AnalyzedJSXEmptyExpression extends DataFlow::AnalyzedValueNode{
  */
 private class AnalyzedSuperCall extends DataFlow::AnalyzedValueNode {
   AnalyzedSuperCall() {
-    astNode = any(SuperCall sc).getCallee().stripParens()
+    astNode = any(SuperCall sc).getCallee().getUnderlyingValue()
   }
 
   override AbstractValue getALocalValue() {

javascript/ql/src/semmle/javascript/frameworks/Bundling.qll

@@ -36,7 +36,7 @@ predicate isBrowserifyBundle(ObjectExpr oe) {
     isBrowserifyBundledModule(p)
   ) and
   // the whole object must be passed to the module loader function
-  exists (CallExpr ce | ce.getCallee().stripParens() instanceof Function |
+  exists (CallExpr ce | ce.getCallee().getUnderlyingValue() instanceof Function |
     // the module loader function always has three arguments
     ce.getNumArgument() = 3 and
     // the first of which is the bundle
@@ -140,10 +140,10 @@ private predicate isWebpackModule(FunctionExpr m) {
  */
 predicate isWebpackBundle(ArrayExpr ae) {
   // ensure that there is at least one bundled module
-  isWebpackModule(ae.getAnElement().stripParens())
+  isWebpackModule(ae.getAnElement().getUnderlyingValue())
   and
   // furthermore, every element is either
-  forall (Expr elt | elt = ae.getAnElement().stripParens() |
+  forall (Expr elt | elt = ae.getAnElement().getUnderlyingValue() |
     // (1) a module
     isWebpackModule(elt)
     or
@@ -158,7 +158,7 @@ predicate isWebpackBundle(ArrayExpr ae) {
   )
   and
   // the whole array must be passed to a module loader function
-  exists (CallExpr ce | ce.getCallee().stripParens() instanceof Function |
+  exists (CallExpr ce | ce.getCallee().getUnderlyingValue() instanceof Function |
     // which is the bundle
     ce.getArgument(0) = ae
   )

javascript/ql/src/semmle/javascript/heuristics/SyntacticHeuristics.qll

@@ -16,10 +16,10 @@ import javascript
 bindingset[regexp]
 predicate isReadFrom(DataFlow::Node read, string regexp) {
   exists (DataFlow::Node actualRead |
-    actualRead = read.asExpr().stripParens().(LogOrExpr).getAnOperand().flow() or // unfold `x || y` once
+    actualRead = read.asExpr().getUnderlyingValue().(LogOrExpr).getAnOperand().flow() or // unfold `x || y` once
     actualRead = read |
     exists (string name | name.regexpMatch(regexp) |
-      actualRead.asExpr().stripParens().(VarAccess).getName() = name or
+      actualRead.asExpr().getUnderlyingValue().(VarAccess).getName() = name or
       actualRead.(DataFlow::PropRead).getPropertyName() = name or
       actualRead.(DataFlow::InvokeNode).getCalleeName() = "get" + name
     )