[llvm] [memprof] Upgrade a unit test to MemProf Version 3 (PR #117063)

[Kazu Hirata via llvm-commits]

https://github.com/kazutakahirata created https://github.com/llvm/llvm-project/pull/117063

This patch upgrades a unit test to MemProf Version 3 while removing
those bits that cannot be upgraded to Version 3.

The bits being removed expect instrprof_error::hash_mismatch from a
broken MemProf profile that references a frame that doesn't actually
exist.  Now, Version 3 no longer issues
instrprof_error::hash_mismatch.  Even if it still issued
instrprof_error::hash_mismatch, we would have a couple of hurdles:

- InstrProfWriter::addMemProfData will soon require all (or none) of
  the fields (frames, call stacks, and records) be populated.  That
  is, it won't accept an instance of IndexedMemProfData with frames
  missing.

- writeMemProfV3 asserts that every frame occurs at least once:

  assert(MemProfData.Frames.size() == FrameHistogram.size());

This patch gives up on instrprof_error::hash_mismatch and tries to
trigger instrprof_error::unknown_function with the empty profile.


>From c2c36c96c5e379a0a3c0a9865f864af1a0eab71a Mon Sep 17 00:00:00 2001
From: Kazu Hirata <kazu at google.com>
Date: Wed, 20 Nov 2024 11:15:53 -0800
Subject: [PATCH] [memprof] Upgrade a unit test to MemProf Version 3

This patch upgrades a unit test to MemProf Version 3 while removing
those bits that cannot be upgraded to Version 3.

The bits being removed expect instrprof_error::hash_mismatch from a
broken MemProf profile that references a frame that doesn't actually
exist.  Now, Version 3 no longer issues
instrprof_error::hash_mismatch.  Even if it still issued
instrprof_error::hash_mismatch, we would have a couple of hurdles:

- InstrProfWriter::addMemProfData will soon require all (or none) of
  the fields (frames, call stacks, and records) be populated.  That
  is, it won't accept an instance of IndexedMemProfData with frames
  missing.

- writeMemProfV3 asserts that every frame occurs at least once:

  assert(MemProfData.Frames.size() == FrameHistogram.size());

This patch gives up on instrprof_error::hash_mismatch and tries to
trigger instrprof_error::unknown_function with the empty profile.
---
 llvm/unittests/ProfileData/InstrProfTest.cpp | 22 +++-----------------
 1 file changed, 3 insertions(+), 19 deletions(-)

diff --git a/llvm/unittests/ProfileData/InstrProfTest.cpp b/llvm/unittests/ProfileData/InstrProfTest.cpp
index 3beab8976304ef..8bd39fd71266af 100644
--- a/llvm/unittests/ProfileData/InstrProfTest.cpp
+++ b/llvm/unittests/ProfileData/InstrProfTest.cpp
@@ -640,29 +640,13 @@ TEST_F(InstrProfTest, test_memprof_getrecord_error) {
   ASSERT_THAT_ERROR(Writer.mergeProfileKind(InstrProfKind::MemProf),
                     Succeeded());
 
-  const IndexedMemProfRecord IndexedMR = makeRecord(
-      /*AllocFrames=*/
-      {
-          {0, 1},
-          {2, 3},
-      },
-      /*CallSiteFrames=*/{
-          {4, 5},
-      });
-  // We skip adding the frame mappings here unlike the test_memprof unit test
-  // above to exercise the failure path when getMemProfRecord is invoked.
-  Writer.addMemProfRecord(/*Id=*/0x9999, IndexedMR);
-
+  Writer.setMemProfVersionRequested(memprof::Version3);
+  // Generate an empty profile.
   auto Profile = Writer.writeBuffer();
   readProfile(std::move(Profile));
 
-  // Missing frames give a hash_mismatch error.
-  auto RecordOr = Reader->getMemProfRecord(0x9999);
-  ASSERT_TRUE(
-      ErrorEquals(instrprof_error::hash_mismatch, RecordOr.takeError()));
-
   // Missing functions give a unknown_function error.
-  RecordOr = Reader->getMemProfRecord(0x1111);
+  auto RecordOr = Reader->getMemProfRecord(0x1111);
   ASSERT_TRUE(
       ErrorEquals(instrprof_error::unknown_function, RecordOr.takeError()));
 }