Rangeanalysis: Remove superfluous ignoreZeroLowerBound.

Author: aschackmull

cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/analysis/RangeAnalysisConstantSpecific.qll

@@ -16,14 +16,6 @@ module CppLangImplConstant implements LangSig<Sem, FloatDelta> {
    */
   predicate ignoreExprBound(SemExpr e) { none() }
 
-  /**
-   * Ignore any inferred zero lower bound on this expression.
-   *
-   * This predicate is to keep the results identical to the original Java implementation. It should be
-   * removed once we have the new implementation matching the old results exactly.
-   */
-  predicate ignoreZeroLowerBound(SemExpr e) { none() }
-
   /**
    * Holds if `e >= bound` (if `upper = false`) or `e <= bound` (if `upper = true`).
    */

cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/analysis/RangeAnalysisRelativeSpecific.qll

@@ -48,14 +48,6 @@ module CppLangImplRelative implements LangSig<Sem, FloatDelta> {
     t instanceof SemFloatingPointType and lb = -(1.0 / 0.0) and ub = 1.0 / 0.0
   }
 
-  /**
-   * Ignore any inferred zero lower bound on this expression.
-   *
-   * This predicate is to keep the results identical to the original Java implementation. It should be
-   * removed once we have the new implementation matching the old results exactly.
-   */
-  predicate ignoreZeroLowerBound(SemExpr e) { none() }
-
   /**
    * Holds if `e >= bound` (if `upper = false`) or `e <= bound` (if `upper = true`).
    */

java/ql/lib/semmle/code/java/dataflow/RangeAnalysis.qll

@@ -373,8 +373,6 @@ module JavaLangImpl implements LangSig<Sem, IntDelta> {
 
   predicate ignoreExprBound(Sem::Expr e) { none() }
 
-  predicate ignoreZeroLowerBound(Sem::Expr e) { none() }
-
   predicate additionalValueFlowStep(Sem::Expr dest, Sem::Expr src, int delta) { none() }
 
   Sem::Type getAlternateType(Sem::Expr e) { none() }

shared/rangeanalysis/codeql/rangeanalysis/RangeAnalysis.qll

@@ -268,14 +268,6 @@ signature module LangSig<Semantic Sem, DeltaSig D> {
    */
   predicate ignoreExprBound(Sem::Expr e);
 
-  /**
-   * Ignore any inferred zero lower bound on this expression.
-   *
-   * This predicate is to keep the results identical to the original Java implementation. It should be
-   * removed once we have the new implementation matching the old results exactly.
-   */
-  predicate ignoreZeroLowerBound(Sem::Expr e);
-
   /**
    * Holds if the value of `dest` is known to be `src + delta`.
    */
@@ -1066,9 +1058,7 @@ module RangeStage<
     or
     upper = false and
     b = D::fromInt(0) and
-    semPositive(e.(Sem::BitAndExpr).getAnOperand()) and
-    // REVIEW: We let the language opt out here to preserve original results.
-    not ignoreZeroLowerBound(e)
+    semPositive(e.(Sem::BitAndExpr).getAnOperand())
   }
 
   /**