[sanitizer] Split dll_thunks into different sanitizers.

When the sanitizer is implemented as a static library and is included in the
main executable, we need an auxiliary static library dll_thunk that will be
linked to the dlls that have instrumentation, so they can refer to the runtime
in the main executable. Basically, it uses interception to get a pointer the
function in the main executable and override its function with that pointer.

Before this diff, all of the implementation for dll_thunks was included in asan.
In this diff I split it into different sanitizers, so we can use other
sanitizers regardless of whether we include asan or not.

All the sanitizers include a file sanitizer_win_dll_thunk.cc that register
functions to be intercepted in the binary section: DLLTH

When the dll including dll_thunk is initialized, it will execute
__dll_thunk_init() implemented in: sanitizer_common/sanitizer_win_dll_thunk.cc,
which will consider all the CB registered in the section DLLTH. So, all the
functions registered will be intercepted, and redirected to the implementation
in the main executable.

All the files "sanitizer_win_dll_thunk.cc" are independent, so we don't need to
include a specific list of sanitizers. Now, we compile:  asan_win_dll_thunk.cc
ubsan_win_dll_thunk.cc,  sanitizer_coverage_win_dll_thunk.cc and
sanitizer_win_dll_thunk.cc, to generate asan_dll_thunk, because we include asan,
ubsan and sanitizer coverage in the address sanitizer library.

Differential Revision: https://reviews.llvm.org/D29154

git-svn-id: https://llvm.org/svn/llvm-project/compiler-rt/trunk@293951 91177308-0d34-0410-b5e6-96231b3b80d8

1 files changed, 21 insertions, 0 deletions

diff --git a/lib/sanitizer_common/sanitizer_coverage_win_dll_thunk.cc b/lib/sanitizer_common/sanitizer_coverage_win_dll_thunk.cc
new file mode 100644
index 000000000..0ab62c074
--- /dev/null
+++ b/lib/sanitizer_common/sanitizer_coverage_win_dll_thunk.cc
@@ -0,0 +1,21 @@
+//===-- sanitizer_coverage_win_dll_thunk.cc -------------------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file is distributed under the University of Illinois Open Source
+// License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file defines a family of thunks that should be statically linked into
+// the DLLs that have instrumentation in order to delegate the calls to the
+// shared runtime that lives in the main binary.
+// See https://github.com/google/sanitizers/issues/209 for the details.
+//===----------------------------------------------------------------------===//
+#ifdef SANITIZER_DLL_THUNK
+#include "sanitizer_win_dll_thunk.h"
+// Sanitizer Coverage interface functions.
+#define INTERFACE_FUNCTION(Name) INTERCEPT_SANITIZER_FUNCTION(Name)
+#define INTERFACE_WEAK_FUNCTION(Name)
+#include "sanitizer_coverage_interface.inc"
+#endif // SANITIZER_DLL_THUNK