[scudo] Allow for compile-time choice of the SizeClassMap

Summary:
With this change, we allow someone to chose the `SizeClassMap` they want to use
at compile time via a define.

I feel somewhat unimaginative with the name of the defines, so if someone has a
better idea, let me know. I have been alternating between those and
`SCUDO_USE_xxx_SIZECLASSMAP` which is clearer but also longer. The issue with
those is that it wouldn't be consistent with `SCUDO_TSD_EXCLUSIVE` that should
probably become `SCUDO_USE_EXCLUSIVE_TSD` maybe?

Anyway, naming is hard, and I am not sure what makes more sense!

Reviewers: alekseyshl, flowerhack

Reviewed By: alekseyshl

Subscribers: llvm-commits, srhines

Differential Revision: https://reviews.llvm.org/D40521

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@319350 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 12 insertions, 11 deletions

diff --git a/lib/scudo/scudo_platform.h b/lib/scudo/scudo_platform.h
index 7db1197fd..a915c9843 100644
--- a/lib/scudo/scudo_platform.h
+++ b/lib/scudo/scudo_platform.h
@@ -49,25 +49,26 @@ namespace __scudo {
 
 #if SANITIZER_CAN_USE_ALLOCATOR64
 # if defined(__aarch64__) && SANITIZER_ANDROID
-const uptr AllocatorSize = 0x2000000000ULL;  // 128G.
-typedef VeryCompactSizeClassMap SizeClassMap;
+const uptr AllocatorSize = 0x4000000000ULL;  // 256G.
 # elif defined(__aarch64__)
 const uptr AllocatorSize = 0x10000000000ULL;  // 1T.
-typedef CompactSizeClassMap SizeClassMap;
 # else
 const uptr AllocatorSize = 0x40000000000ULL;  // 4T.
-typedef CompactSizeClassMap SizeClassMap;
 # endif
 #else
-# if SANITIZER_ANDROID
-static const uptr RegionSizeLog = 19;
-typedef VeryCompactSizeClassMap SizeClassMap;
-# else
-static const uptr RegionSizeLog = 20;
-typedef CompactSizeClassMap SizeClassMap;
-# endif
+const uptr RegionSizeLog = SANITIZER_ANDROID ? 19 : 20;
 #endif  // SANITIZER_CAN_USE_ALLOCATOR64
 
+#if !defined(SCUDO_SIZE_CLASS_MAP)
+# define SCUDO_SIZE_CLASS_MAP Default
+#endif
+
+#define SIZE_CLASS_MAP_TYPE SIZE_CLASS_MAP_TYPE_(SCUDO_SIZE_CLASS_MAP)
+#define SIZE_CLASS_MAP_TYPE_(T) SIZE_CLASS_MAP_TYPE__(T)
+#define SIZE_CLASS_MAP_TYPE__(T) T##SizeClassMap
+
+typedef SIZE_CLASS_MAP_TYPE SizeClassMap;
+
 }  // namespace __scudo
 
 #endif // SCUDO_PLATFORM_H_