[SanitizerCommon] Test `CombinedAllocator::ForEachChunk()` in unit tests.

[delcypher]

Summary

[SanitizerCommon] Test CombinedAllocator::ForEachChunk() in unit tests.

Previously we weren't testing this function in the unit tests.

[kubamracek]

LGTM, of course (more tests, yay!).

The indentation makes this hard to read though. Maybe declare the lambda as a separate variable?

[delcypher]

In D54861#1308171, @kubamracek wrote:

LGTM, of course (more tests, yay!).

The indentation makes this hard to read though. Maybe declare the lambda as a separate variable?

The indentation is clang-format's doing. I'm a bit hesitant to put the lambda in a variable because it's only used in one place so putting it inline is the more standard thing to do.
However, I don't have a super strong opinion here so if you think it's clearer then I'll make the change.

[delcypher]

Make inline lambda into a variable instead for readability.

[delcypher]

In D54861#1308535, @delcypher wrote:

In D54861#1308171, @kubamracek wrote:

LGTM, of course (more tests, yay!).

The indentation makes this hard to read though. Maybe declare the lambda as a separate variable?

The indentation is clang-format's doing. I'm a bit hesitant to put the lambda in a variable because it's only used in one place so putting it inline is the more standard thing to do.
However, I don't have a super strong opinion here so if you think it's clearer then I'll make the change.

@kubamracek I tried assigning the lambda to a local variable. You're right, it is more readable. I've updated this patch with that change.

[delcypher]

@kcc Is it okay to land this?

[delcypher]

I'm just going to land this. It's a testing only change so it's not going to break anything that actually ships. I can revert it if necessary if there is a problem.

lib/sanitizer_common/tests/sanitizer_allocator_test.cc

for (uptr i = 0; i < kNumAllocs; i++) {
       uptr *meta = reinterpret_cast<uptr*>(a->GetMetaData(x));
       CHECK_EQ(*meta, 0);
       *meta = size;
       allocated.push_back(x);
     }
 
     std::shuffle(allocated.begin(), allocated.end(), r);
 
+    // Test ForEachChunk(...)
+    {
+      std::set<void *> reported_chunks;
+      auto cb = [](uptr chunk, void *arg) {
+        auto reported_chunks_ptr = reinterpret_cast<std::set<void *> *>(arg);
+        auto pair =
+            reported_chunks_ptr->insert(reinterpret_cast<void *>(chunk));
+        // Check chunk is never reported more than once.
+        ASSERT_TRUE(pair.second);
+      };
+      a->ForEachChunk(cb, reinterpret_cast<void *>(&reported_chunks));
+      for (const auto &allocated_ptr : allocated) {
+        ASSERT_NE(reported_chunks.find(allocated_ptr), reported_chunks.end());
+      }
+    }
+
     for (uptr i = 0; i < kNumAllocs; i++) {
       void *x = allocated[i];
       uptr *meta = reinterpret_cast<uptr*>(a->GetMetaData(x));
       CHECK_NE(*meta, 0);
       CHECK(a->PointerIsMine(x));
       *meta = 0;
       a->Deallocate(&cache, x);
     }