Merge pull request #10339 from MathiasVP/dont-use-get-unique-id-in-range-analysis

C++: Don't use `getUniqueId` in range analysis

cpp/ql/lib/experimental/semmle/code/cpp/rangeanalysis/Bound.qll

@@ -73,7 +73,7 @@ class ValueNumberBound extends Bound, TBoundValueNumber {
     this = TBoundValueNumber(valueNumber(result)) and delta = 0
   }
 
-  override string toString() { result = vn.getExampleInstruction().toString() }
+  override string toString() { result = "ValueNumberBound" }
 
   override Location getLocation() { result = vn.getLocation() }
 

cpp/ql/lib/experimental/semmle/code/cpp/semantic/SemanticExprSpecific.qll

@@ -112,12 +112,11 @@ module SemanticExprConfig {
 
   predicate hasDominanceInformation(BasicBlock block) { any() }
 
-  int getBasicBlockUniqueId(BasicBlock block) {
-    // REVIEW: `getDisplayIndex()` is not intended for use in real queries, but for now it's the
-    // best we can do because `equivalentRelation` won't accept a predicate whose parameters are IPA
-    // types.
-    result = block.getDisplayIndex()
-  }
+  private predicate id(Cpp::Locatable x, Cpp::Locatable y) { x = y }
+
+  private predicate idOf(Cpp::Locatable x, int y) = equivalenceRelation(id/2)(x, y)
+
+  int getBasicBlockUniqueId(BasicBlock block) { idOf(block.getFirstInstruction().getAst(), result) }
 
   newtype TSsaVariable =
     TSsaInstruction(IR::Instruction instr) { instr.hasMemoryResult() } or
@@ -267,17 +266,7 @@ module SemanticExprConfig {
 
     ValueNumberBound() { bound = this }
 
-    override string toString() {
-      result =
-        min(SsaVariable v |
-          v.asInstruction() = bound.getValueNumber().getAnInstruction()
-        |
-          v
-          order by
-            v.asInstruction().getBlock().getDisplayIndex(),
-            v.asInstruction().getDisplayIndexInBlock()
-        ).toString()
-    }
+    override string toString() { result = bound.toString() }
   }
 
   predicate zeroBound(Bound bound) { bound instanceof IRBound::ZeroBound }