C++: Rename from 'getAllocation' to 'getAnAllocation'.

Author: MathiasVP

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/internal/AliasedSSA.qll

@@ -123,7 +123,12 @@ abstract class MemoryLocation extends TMemoryLocation {
 
   abstract predicate isMayAccess();
 
-  Allocation getAllocation() { none() }
+  /**
+   * Gets an allocation associated with this `MemoryLocation`.
+   *
+   * This always returns zero or one result.
+   */
+  Allocation getAnAllocation() { none() }
 
   /**
    * Holds if the location cannot be overwritten except by definition of a `MemoryLocation` for
@@ -177,7 +182,7 @@ abstract class AllocationMemoryLocation extends MemoryLocation {
 
   final override Location getLocation() { result = var.getLocation() }
 
-  final override Allocation getAllocation() { result = var }
+  final override Allocation getAnAllocation() { result = var }
 
   final override predicate isMayAccess() { isMayAccess = true }
 
@@ -453,15 +458,15 @@ private Overlap getExtentOverlap(MemoryLocation def, MemoryLocation use) {
       result instanceof MustExactlyOverlap
       or
       not use instanceof EntireAllocationMemoryLocation and
-      if def.getAllocation() = use.getAllocation()
+      if def.getAnAllocation() = use.getAnAllocation()
       then
         // EntireAllocationMemoryLocation totally overlaps any location within
         // the same allocation.
         result instanceof MustTotallyOverlap
       else (
         // There is no overlap with a location that's known to belong to a
         // different allocation, but all other locations may partially overlap.
-        not exists(use.getAllocation()) and
+        not exists(use.getAnAllocation()) and
         result instanceof MayPartiallyOverlap
       )
     )
@@ -541,15 +546,15 @@ private predicate isCoveredOffset(Allocation var, int offsetRank, VariableMemory
   exists(int startRank, int endRank, VirtualVariable vvar |
     vml.getStartBitOffset() = rank[startRank](IntValue offset_ | isRelevantOffset(vvar, offset_)) and
     vml.getEndBitOffset() = rank[endRank](IntValue offset_ | isRelevantOffset(vvar, offset_)) and
-    var = vml.getAllocation() and
+    var = vml.getAnAllocation() and
     vvar = vml.getVirtualVariable() and
     isRelatableMemoryLocation(vml) and
     offsetRank in [startRank .. endRank]
   )
 }
 
 private predicate hasUnknownOffset(Allocation var, VariableMemoryLocation vml) {
-  vml.getAllocation() = var and
+  vml.getAnAllocation() = var and
   (
     vml.getStartBitOffset() = Ints::unknown() or
     vml.getEndBitOffset() = Ints::unknown()
@@ -564,9 +569,9 @@ private predicate overlappingIRVariableMemoryLocations(
     isCoveredOffset(var, offsetRank, use)
   )
   or
-  hasUnknownOffset(use.getAllocation(), def)
+  hasUnknownOffset(use.getAnAllocation(), def)
   or
-  hasUnknownOffset(def.getAllocation(), use)
+  hasUnknownOffset(def.getAnAllocation(), use)
 }
 
 private Overlap getVariableMemoryLocationOverlap(

cpp/ql/lib/semmle/code/cpp/ir/implementation/aliased_ssa/internal/SSAConstruction.qll

@@ -143,7 +143,7 @@ private module Cached {
     // conflated if it's associated with a conflated location.
     exists(Alias::MemoryLocation location |
       instruction = getPhi(_, location) and
-      not exists(location.getAllocation())
+      not exists(location.getAnAllocation())
     )
   }
 

cpp/ql/lib/semmle/code/cpp/ir/implementation/unaliased_ssa/internal/SimpleSSA.qll

@@ -48,7 +48,7 @@ predicate canReuseSsaForVariable(IRAutomaticVariable var) {
 
 private newtype TMemoryLocation = MkMemoryLocation(Allocation var) { isVariableModeled(var) }
 
-private MemoryLocation getMemoryLocation(Allocation var) { result.getAllocation() = var }
+private MemoryLocation getMemoryLocation(Allocation var) { result.getAnAllocation() = var }
 
 class MemoryLocation extends TMemoryLocation {
   Allocation var;
@@ -57,7 +57,7 @@ class MemoryLocation extends TMemoryLocation {
 
   final string toString() { result = var.getAllocationString() }
 
-  final Allocation getAllocation() { result = var }
+  final Allocation getAnAllocation() { result = var }
 
   final Language::Location getLocation() { result = var.getLocation() }
 

cpp/ql/test/library-tests/ir/points_to/points_to.ql

@@ -56,7 +56,7 @@ module UnaliasedSsa {
         not memLocation.getVirtualVariable() instanceof AliasedVirtualVariable and
         not memLocation instanceof AllNonLocalMemory and
         tag = "ussa" and
-        not ignoreAllocation(memLocation.getAllocation().getAllocationString()) and
+        not ignoreAllocation(memLocation.getAnAllocation().getAllocationString()) and
         value = memLocation.toString() and
         element = instr.toString() and
         location = instr.getLocation() and