[compiler-rt][lsan][Fuchsia] Adjust lsan allocator settings

[PiJoules]

These now match the settings for the asan allocator on Fuchsia+RISCV.

[llvmbot]

@llvm/pr-subscribers-compiler-rt-sanitizer

Author: None (PiJoules)

Changes

These now match the settings for the asan allocator on Fuchsia+RISCV.

---

Full diff: https://github.com/llvm/llvm-project/pull/69401.diff

1 Files Affected:

• (modified) compiler-rt/lib/lsan/lsan_allocator.h (+21-1)

diff --git a/compiler-rt/lib/lsan/lsan_allocator.h b/compiler-rt/lib/lsan/lsan_allocator.h
index f5486150a8121f1..7761e7f1e2ebd14 100644
--- a/compiler-rt/lib/lsan/lsan_allocator.h
+++ b/compiler-rt/lib/lsan/lsan_allocator.h
@@ -68,23 +68,43 @@ using PrimaryAllocator = PrimaryAllocatorASVT<LocalAddressSpaceView>;
 #else
 # if SANITIZER_FUCHSIA || defined(__powerpc64__)
 const uptr kAllocatorSpace = ~(uptr)0;
+#    if SANITIZER_RISCV64
+// See the comments in compiler-rt/lib/asan/asan_allocator.h for why these
+// values were chosen.
+const uptr kAllocatorSize = UINT64_C(1) << 33;  // 8GB
+typedef SizeClassMap</*kNumBits=*/2,
+                     /*kMinSizeLog=*/5,
+                     /*kMidSizeLog=*/8,
+                     /*kMaxSizeLog=*/18,
+                     /*kNumCachedHintT=*/8,
+                     /*kMaxBytesCachedLog=*/10>
+    SizeClassMap;
+static_assert(SizeClassMap::kNumClassesRounded <= 32,
+              "32 size classes is the optimal number to ensure tests run "
+              "effieciently on Fuchsia.");
+#    else
 const uptr kAllocatorSize  =  0x40000000000ULL;  // 4T.
+typedef DefaultSizeClassMap SizeClassMap;
+#    endif
 #  elif SANITIZER_RISCV64
 const uptr kAllocatorSpace = ~(uptr)0;
 const uptr kAllocatorSize = 0x2000000000ULL;  // 128G.
+typedef DefaultSizeClassMap SizeClassMap;
 #  elif SANITIZER_APPLE
 const uptr kAllocatorSpace = 0x600000000000ULL;
 const uptr kAllocatorSize  = 0x40000000000ULL;  // 4T.
+typedef DefaultSizeClassMap SizeClassMap;
 #  else
 const uptr kAllocatorSpace = 0x500000000000ULL;
 const uptr kAllocatorSize = 0x40000000000ULL;  // 4T.
+typedef DefaultSizeClassMap SizeClassMap;
 #  endif
 template <typename AddressSpaceViewTy>
 struct AP64 {  // Allocator64 parameters. Deliberately using a short name.
   static const uptr kSpaceBeg = kAllocatorSpace;
   static const uptr kSpaceSize = kAllocatorSize;
   static const uptr kMetadataSize = sizeof(ChunkMetadata);
-  typedef DefaultSizeClassMap SizeClassMap;
+  typedef SizeClassMap SizeClassMap;
   typedef NoOpMapUnmapCallback MapUnmapCallback;
   static const uptr kFlags = 0;
   using AddressSpaceView = AddressSpaceViewTy;

[frobtech]

This renaming does not seem at all desirable. I'm a little amazed it even works.
The RHS here should be DefaultSizeClassMap and none of the changes outside this #if block should be made, AFAICT.

[PiJoules]

Uhh I don't know how to handle dependent changes on github to allow for only showing the diff between this and its dependent patch, but I have #69526 for renaming which should make this patch cleaner.

[frobtech]

lgtm