[compiler-rt] Add support for the dynamic shadow allocation

Summary:
This patch is adding support for dynamic shadow allocation.

This is a merge and re-commit of the following patches.

```
[compiler-rt] Fix Asan build on Android
  https://reviews.llvm.org/D24768
[compiler-rt] Add support for the dynamic shadow allocation
  https://reviews.llvm.org/D23363
```

This patch needed to re-land at the same time:
```
[asan] Support dynamic shadow address instrumentation
  https://reviews.llvm.org/D23354
```

Reviewers: rnk, zaks.anna

Subscribers: tberghammer, danalbert, kubabrecka, dberris, chrisha, llvm-commits

Differential Revision: https://reviews.llvm.org/D25104

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@282882 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 3 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_common.h b/lib/sanitizer_common/sanitizer_common.h
index 2de93ebae..779e96fe6 100644
--- a/lib/sanitizer_common/sanitizer_common.h
+++ b/lib/sanitizer_common/sanitizer_common.h
@@ -98,6 +98,9 @@ void *MmapAlignedOrDie(uptr size, uptr alignment, const char *mem_type);
 bool MprotectNoAccess(uptr addr, uptr size);
 bool MprotectReadOnly(uptr addr, uptr size);
 
+// Find an available address space.
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding);
+
 // Used to check if we can map shadow memory to a fixed location.
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end);
 void ReleaseMemoryToOS(uptr addr, uptr size);