[llvm] [memprof] Add Version2 of the indexed MemProf format (PR #89100)

[Snehasish Kumar via llvm-commits]

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@@ -1296,20 +1308,30 @@ Error IndexedInstrProfReader::readHeader() {
     MemProfRecordTable.reset(MemProfRecordHashTable::Create(
         /*Buckets=*/Start + RecordTableOffset,
         /*Payload=*/Ptr,
-        /*Base=*/Start, memprof::RecordLookupTrait(memprof::Version1, Schema)));
+        /*Base=*/Start, memprof::RecordLookupTrait(Version, Schema)));
 
     // Initialize the frame table reader with the payload and bucket offsets.
     MemProfFrameTable.reset(MemProfFrameHashTable::Create(
         /*Buckets=*/Start + FrameTableOffset,
         /*Payload=*/Start + FramePayloadOffset,
         /*Base=*/Start, memprof::FrameLookupTrait()));
 
+    if (Version >= memprof::Version2)
+      MemProfCallStackTable.reset(MemProfCallStackHashTable::Create(
+          /*Buckets=*/Start + CallStackTableOffset,
+          /*Payload=*/Start + CallStackPayloadOffset,
+          /*Base=*/Start, memprof::CallStackLookupTrait()));
+
 #ifdef EXPENSIVE_CHECKS
     // Go through all the records and verify that CSId has been correctly
     // populated.  Do this only under EXPENSIVE_CHECKS.  Otherwise, we
     // would defeat the purpose of OnDiskIterableChainedHashTable.
-    for (const auto &Record : MemProfRecordTable->data())
-      verifyIndexedMemProfRecord(Record);
+    // Note that we can compare CSId against actual call stacks only for
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snehasish wrote:

Should this be a TODO or FIXME to update the condition in the future?

https://github.com/llvm/llvm-project/pull/89100