changes based on review

Author: erik-krogh

javascript/ql/src/Declarations/DeadStoreOfLocal.ql

@@ -29,23 +29,6 @@ predicate deadStoreOfLocal(VarDef vd, PurelyLocalVariable v) {
   not exists(SsaExplicitDefinition ssa | ssa.defines(vd, v))
 }
 
-/**
- * Holds if there exists another definition of the variable `v` that dominates `dead`.
- */
-predicate hasDominatingDef(VarDef dead, PurelyLocalVariable v) {
-  exists(VarDef otherDef | not otherDef = dead and otherDef.getAVariable() = v |
-    dead.getBasicBlock().getASuccessor+() = otherDef.getBasicBlock()
-    or
-    exists(ReachableBasicBlock bb, int i, int j |
-      bb = otherDef.getBasicBlock() and bb = dead.getBasicBlock()
-    |
-      bb.defAt(i, v, dead) and
-      bb.defAt(j, v, otherDef) and
-      j > i
-    )
-  )
-}
-
 from VarDef dead, PurelyLocalVariable v, string msg
 where
   deadStoreOfLocal(dead, v) and
@@ -80,8 +63,10 @@ where
   (
     // To avoid confusion about the meaning of "definition" and "declaration" we avoid
     // the term "definition" when the alert location is a variable declaration.
-    if dead instanceof VariableDeclarator and hasDominatingDef(dead, v)
+    if
+      dead instanceof VariableDeclarator and
+      not exists(SsaImplicitInit init | init.getVariable().getSourceVariable() = v) // the variable is dead at the hoisted implicit initialization. 
     then msg = "The initial value of " + v.getName() + " is unused, since it is always overwritten."
-    else msg = "This definition of " + v.getName() + " is useless, since its value is never read."
+    else msg = "The value assigned to " + v.getName() + " here is unused."
   )
 select dead, msg

javascript/ql/test/query-tests/Declarations/DeadStoreOfLocal/DeadStoreOfLocal.expected

@@ -1,13 +1,13 @@
-| overload.ts:10:12:10:14 | baz | This definition of baz is useless, since its value is never read. |
+| overload.ts:10:12:10:14 | baz | The value assigned to baz here is unused. |
 | tst2.js:26:9:26:14 | x = 23 | The initial value of x is unused, since it is always overwritten. |
-| tst2.js:28:9:28:14 | x = 42 | This definition of x is useless, since its value is never read. |
-| tst3.js:2:1:2:36 | exports ... a: 23 } | This definition of exports is useless, since its value is never read. |
-| tst3b.js:2:18:2:36 | exports = { a: 23 } | This definition of exports is useless, since its value is never read. |
-| tst.js:6:2:6:7 | y = 23 | This definition of y is useless, since its value is never read. |
+| tst2.js:28:9:28:14 | x = 42 | The value assigned to x here is unused. |
+| tst3.js:2:1:2:36 | exports ... a: 23 } | The value assigned to exports here is unused. |
+| tst3b.js:2:18:2:36 | exports = { a: 23 } | The value assigned to exports here is unused. |
+| tst.js:6:2:6:7 | y = 23 | The value assigned to y here is unused. |
 | tst.js:13:6:13:11 | a = 23 | The initial value of a is unused, since it is always overwritten. |
-| tst.js:13:14:13:19 | a = 42 | This definition of a is useless, since its value is never read. |
+| tst.js:13:14:13:19 | a = 42 | The value assigned to a here is unused. |
 | tst.js:45:6:45:11 | x = 23 | The initial value of x is unused, since it is always overwritten. |
 | tst.js:51:6:51:11 | x = 23 | The initial value of x is unused, since it is always overwritten. |
 | tst.js:132:7:132:13 | {x} = o | The initial value of x is unused, since it is always overwritten. |
 | tst.js:162:6:162:14 | [x] = [0] | The initial value of x is unused, since it is always overwritten. |
-| tst.js:172:7:172:17 | nSign = foo | This definition of nSign is useless, since its value is never read. |
+| tst.js:172:7:172:17 | nSign = foo | The value assigned to nSign here is unused. |