[analyzer] [NFC] remove duplicated function

[george.karpenkov]

Summary

Two copies of getSymLERange in RangeConstraintManager are virtually identical, which is clearly bad.
This patch uses lambdas to call one from another (assuming that we would like to avoid getting ranges from the state when necessary).

If the latter is not even the concern, it would be even easier to do the computation eagerly, and then pass RangeSet directly instead of a lambda.

[george.karpenkov]

@dcoughlin @NoQ OK to commit?

[NoQ]

Yep, looks good.

lib/StaticAnalyzer/Core/RangeConstraintManager.cpp

RangeSet getSymLTRange(ProgramStateRef St, SymbolRef Sym,
                          const llvm::APSInt &Int,
                          const llvm::APSInt &Adjustment);
   RangeSet getSymGTRange(ProgramStateRef St, SymbolRef Sym,
                          const llvm::APSInt &Int,
                          const llvm::APSInt &Adjustment);
   RangeSet getSymLERange(ProgramStateRef St, SymbolRef Sym,
                          const llvm::APSInt &Int,
                          const llvm::APSInt &Adjustment);
-  RangeSet getSymLERange(const RangeSet &RS, const llvm::APSInt &Int,
+  RangeSet getSymLERange(llvm::function_ref<RangeSet()> RS,
+                         const llvm::APSInt &Int,
                          const llvm::APSInt &Adjustment);
   RangeSet getSymGERange(ProgramStateRef St, SymbolRef Sym,
                          const llvm::APSInt &Int,
                          const llvm::APSInt &Adjustment);
 };
 
 } // end anonymous namespace
 

 ProgramStateRef
 RangeConstraintManager::assumeSymGE(ProgramStateRef St, SymbolRef Sym,
                                     const llvm::APSInt &Int,
                                     const llvm::APSInt &Adjustment) {
   RangeSet New = getSymGERange(St, Sym, Int, Adjustment);
   return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
 }
 
-RangeSet RangeConstraintManager::getSymLERange(const RangeSet &RS,
-                                               const llvm::APSInt &Int,
-                                               const llvm::APSInt &Adjustment) {
+RangeSet RangeConstraintManager::getSymLERange(
+      llvm::function_ref<RangeSet()> RS,
   // Before we do any real work, see if the value can even show up.
   APSIntType AdjustmentType(Adjustment);
   switch (AdjustmentType.testInRange(Int, true)) {
   case APSIntType::RTR_Below:
     return F.getEmptySet();
   case APSIntType::RTR_Within:
     break;
   case APSIntType::RTR_Above:
-    return RS;
+    return RS();
   }
 
   // Special case for Int == Max. This is always feasible.
   llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
   llvm::APSInt Max = AdjustmentType.getMaxValue();
   if (ComparisonVal == Max)
-    return RS;
+    return RS();
 
   llvm::APSInt Min = AdjustmentType.getMinValue();
   llvm::APSInt Lower = Min - Adjustment;
   llvm::APSInt Upper = ComparisonVal - Adjustment;
 
-  return RS.Intersect(getBasicVals(), F, Lower, Upper);
+  return RS().Intersect(getBasicVals(), F, Lower, Upper);
 }
 
 RangeSet RangeConstraintManager::getSymLERange(ProgramStateRef St,
                                                SymbolRef Sym,
                                                const llvm::APSInt &Int,
                                                const llvm::APSInt &Adjustment) {
-  // Before we do any real work, see if the value can even show up.
-  APSIntType AdjustmentType(Adjustment);
-  switch (AdjustmentType.testInRange(Int, true)) {
-  case APSIntType::RTR_Below:
-    return F.getEmptySet();
-  case APSIntType::RTR_Within:
-    break;
-  case APSIntType::RTR_Above:
-    return getRange(St, Sym);
-  }
-
-  // Special case for Int == Max. This is always feasible.
-  llvm::APSInt ComparisonVal = AdjustmentType.convert(Int);
-  llvm::APSInt Max = AdjustmentType.getMaxValue();
-  if (ComparisonVal == Max)
-    return getRange(St, Sym);
-
-  llvm::APSInt Min = AdjustmentType.getMinValue();
-  llvm::APSInt Lower = Min - Adjustment;
-  llvm::APSInt Upper = ComparisonVal - Adjustment;
-
-  return getRange(St, Sym).Intersect(getBasicVals(), F, Lower, Upper);
+  return getSymLERange([&] { return getRange(St, Sym); }, Int, Adjustment);
 }
 
 ProgramStateRef
 RangeConstraintManager::assumeSymLE(ProgramStateRef St, SymbolRef Sym,
                                     const llvm::APSInt &Int,
                                     const llvm::APSInt &Adjustment) {
   RangeSet New = getSymLERange(St, Sym, Int, Adjustment);
   return New.isEmpty() ? nullptr : St->set<ConstraintRange>(Sym, New);
 }
 
 ProgramStateRef RangeConstraintManager::assumeSymWithinInclusiveRange(
     ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
     const llvm::APSInt &To, const llvm::APSInt &Adjustment) {
   RangeSet New = getSymGERange(State, Sym, From, Adjustment);
   if (New.isEmpty())
     return nullptr;
-  New = getSymLERange(New, To, Adjustment);
-  return New.isEmpty() ? nullptr : State->set<ConstraintRange>(Sym, New);
+  RangeSet Out = getSymLERange([&] { return New; }, To, Adjustment);
+  return Out.isEmpty() ? nullptr : State->set<ConstraintRange>(Sym, Out);
 }
 
 ProgramStateRef RangeConstraintManager::assumeSymOutsideInclusiveRange(
     ProgramStateRef State, SymbolRef Sym, const llvm::APSInt &From,
     const llvm::APSInt &To, const llvm::APSInt &Adjustment) {
   RangeSet RangeLT = getSymLTRange(State, Sym, From, Adjustment);
   RangeSet RangeGT = getSymGTRange(State, Sym, To, Adjustment);
   RangeSet New(RangeLT.addRange(F, RangeGT));