fix: replace instanceof back with extends to fix malloc_line problem

Author: Lslightly

qlsrc/pprof_ext/cpuprofile.qll

@@ -21,13 +21,16 @@ float timeInUnit(QlBuiltins::BigInt t, string unit, int precision) {
 /**
  * Extension of Profile providing aggregation methods for CPU sampling data.
  */
-class CPUProfile instanceof Profile {
+class CPUProfile extends Profile {
     CPUProfile() {
-        any()
+        super.getPeriodType().getType() = "cpu" and 
+        super.getPeriodType().getUnit() = "nanoseconds" and
+        super.getSampleType(0).getType() = "samples" and
+        super.getSampleType(0).getUnit() = "count" and
+        super.getSampleType(1).getType() = "cpu" and 
+        super.getSampleType(1).getUnit() = "nanoseconds"
     }
 
-    string toString() { result = "CPUProfile " + this.(int).toString() }
-
     /**
      * Sum of all sample values at index 1 (total time in nanoseconds).
      */
@@ -99,5 +102,11 @@ class CPUProfile instanceof Profile {
             | sample.getValue(1)
         )
     }
+
+    string flameGraphRootFuncName() {
+        exists(Sample sample
+            | sample.getLocation(sample.locationNum()-1).getLastLine().getFunction().getName() = result
+        )
+    }
 }
 

qlsrc/pprof_ext/heapprofile.qll

@@ -16,7 +16,7 @@ import profile
  * Each sample also carries a numeric label "bytes" indicating
  * the average block size (AllocBytes / AllocObjects) for that sample.
  */
-class HeapProfile instanceof Profile {
+class HeapProfile extends Profile {
     HeapProfile() {
         // Period type must be ("space", "bytes")
         super.getPeriodType().getType() = "space" and
@@ -33,9 +33,6 @@ class HeapProfile instanceof Profile {
         super.getSampleType(3).getUnit() = "bytes"
     }
 
-    string toString() {
-        result = "HeapProfile " + this.(int).toString()
-    }
 
     // -----------------------------------------------------------------------
     // Sum helpers — total across all samples for each value index