C++: respond to overflow PR comments

Author: rdmarsh2

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

@@ -21,7 +21,7 @@ module FloatDelta implements DeltaSig {
 }
 
 module FloatOverflow implements OverflowSig<FloatDelta> {
-  predicate semExprDoesntOverflow(boolean positively, SemExpr expr) {
+  predicate semExprDoesNotOverflow(boolean positively, SemExpr expr) {
     exists(float lb, float ub, float delta |
       typeBounds(expr.getSemType(), lb, ub) and 
       ConstantStage::initialBounded(expr, any(ConstantBounds::SemZeroBound b), delta, positively, _, _, _)
@@ -31,17 +31,8 @@ module FloatOverflow implements OverflowSig<FloatDelta> {
       positively = false and delta > lb
     )
   }
-/*
-  predicate semExprOverflow(float delta, boolean upper, SemExpr expr) {
-    exists(float lb, float ub | typeBounds(expr.getSemType(), lb, ub) |
-      upper = false and delta < lb
-      or
-      upper = true and delta > ub
-    )
-  }
-  */
 
-  predicate typeBounds(SemType t, float lb, float ub) {
+  additional predicate typeBounds(SemType t, float lb, float ub) {
     exists(SemIntegerType integralType, float limit |
       integralType = t and limit = 2.pow(8 * integralType.getByteSize())
     |

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

@@ -6,7 +6,7 @@ private import semmle.code.cpp.rangeanalysis.new.internal.semantic.Semantic
 private import RangeAnalysisStage
 private import semmle.code.cpp.rangeanalysis.new.internal.semantic.analysis.FloatDelta
 
-module CppLangImpl implements LangSig<FloatDelta> {
+module CppLangImplConstant implements LangSig<FloatDelta> {
   /**
    * Holds if the specified expression should be excluded from the result of `ssaRead()`.
    *

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

@@ -1,5 +1,6 @@
 private import RangeAnalysisStage 
-private import RangeAnalysisSpecific
+private import RangeAnalysisConstantSpecific
+private import RangeAnalysisRelativeSpecific
 private import semmle.code.cpp.rangeanalysis.new.internal.semantic.analysis.FloatDelta
 private import RangeUtils
 private import semmle.code.cpp.rangeanalysis.new.internal.semantic.SemanticBound as SemanticBound
@@ -47,10 +48,10 @@ module RelativeBounds implements BoundSig<FloatDelta> {
 }
 
 module ConstantStage =
-  RangeStage<FloatDelta, ConstantBounds, FloatOverflow, CppLangImpl, RangeUtil<FloatDelta, CppLangImpl>>;
+  RangeStage<FloatDelta, ConstantBounds, FloatOverflow, CppLangImplConstant, RangeUtil<FloatDelta, CppLangImplConstant>>;
 
 module RelativeStage =
-  RangeStage<FloatDelta, RelativeBounds, FloatOverflow, CppLangImpl, RangeUtil<FloatDelta, CppLangImpl>>;
+  RangeStage<FloatDelta, RelativeBounds, FloatOverflow, CppLangImplRelative, RangeUtil<FloatDelta, CppLangImplRelative>>;
 
 private newtype TSemReason =
   TSemNoReason() or

cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/analysis/RangeAnalysisSpecific2.qll renamed to cpp/ql/lib/semmle/code/cpp/rangeanalysis/new/internal/semantic/analysis/RangeAnalysisRelativeSpecific.qll

@@ -9,7 +9,7 @@ private import semmle.code.cpp.rangeanalysis.new.internal.semantic.analysis.IntD
 private import RangeAnalysisImpl
 private import semmle.code.cpp.rangeanalysis.RangeAnalysisUtils
 
-module CppLangImpl2 implements LangSig<FloatDelta> {
+module CppLangImplRelative implements LangSig<FloatDelta> {
   /**
    * Holds if the specified expression should be excluded from the result of `ssaRead()`.
    *

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

@@ -242,7 +242,7 @@ signature module BoundSig<DeltaSig D> {
 }
 
 signature module OverflowSig<DeltaSig D> {
-  predicate semExprDoesntOverflow(boolean positively, SemExpr expr);
+  predicate semExprDoesNotOverflow(boolean positively, SemExpr expr);
 }
 
 module RangeStage<
@@ -935,12 +935,10 @@ module RangeStage<
   ) {
     initialBounded(e, b, delta, upper, fromBackEdge, origdelta, reason) and
     (
-      semExprDoesntOverflow(upper.booleanNot(), e)
+      semExprDoesNotOverflow(upper.booleanNot(), e)
       or
       not potentiallyOverflowingExpr(upper.booleanNot(), e)
       or
-      initialBounded(e, any(SemZeroBound z), _, upper.booleanNot(), _, _, _)
-      or
       exists(D::Delta otherDelta |
         initialBounded(e, _, otherDelta, upper.booleanNot(), _, _, _) and
         (

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

@@ -3,7 +3,7 @@
  */
 
 private import semmle.code.cpp.rangeanalysis.new.internal.semantic.Semantic
-private import RangeAnalysisSpecific
+private import RangeAnalysisRelativeSpecific
 private import RangeAnalysisStage as Range
 private import ConstantAnalysis