[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, 20 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_win.cc b/lib/sanitizer_common/sanitizer_win.cc
index 7555360c6..1fd79231d 100644
--- a/lib/sanitizer_common/sanitizer_win.cc
+++ b/lib/sanitizer_common/sanitizer_win.cc
@@ -249,6 +249,26 @@ void DontDumpShadowMemory(uptr addr, uptr length) {
   // FIXME: add madvise-analog when we move to 64-bits.
 }
 
+uptr FindAvailableMemoryRange(uptr size, uptr alignment, uptr left_padding) {
+  uptr address = 0;
+  while (true) {
+    MEMORY_BASIC_INFORMATION info;
+    if (!::VirtualQuery((void*)address, &info, sizeof(info)))
+      return 0;
+
+    if (info.State == MEM_FREE) {
+      uptr shadow_address = RoundUpTo((uptr)info.BaseAddress + left_padding,
+                                      alignment);
+      if (shadow_address + size < (uptr)info.BaseAddress + info.RegionSize)
+        return shadow_address;
+    }
+
+    // Move to the next region.
+    address = (uptr)info.BaseAddress + info.RegionSize;
+  }
+  return 0;
+}
+
 bool MemoryRangeIsAvailable(uptr range_start, uptr range_end) {
   MEMORY_BASIC_INFORMATION mbi;
   CHECK(VirtualQuery((void *)range_start, &mbi, sizeof(mbi)));