[compiler-rt] Do not introduce __sanitizer namespace globally

The definitions in sanitizer_common may conflict with definitions from system headers because:

The runtime includes the system headers after the project headers (as per LLVM coding guidelines).
lib/sanitizer_common/sanitizer_internal_defs.h pollutes the namespace of everything defined after it, which is all/most of the sanitizer .h and .cc files and the included system headers with: using namespace __sanitizer; // NOLINT
This patch solves the problem by introducing the namespace only within the sanitizer namespaces as proposed by Dmitry.

Differential Revision: https://reviews.llvm.org/D21947

llvm-svn: 281657

1 files changed, 2 insertions, 0 deletions

diff --git a/compiler-rt/lib/safestack/safestack.cc b/compiler-rt/lib/safestack/safestack.cc
index 92c24b35d6d..b194b6cfa8f 100644
--- a/compiler-rt/lib/safestack/safestack.cc
+++ b/compiler-rt/lib/safestack/safestack.cc
@@ -92,6 +92,8 @@ static __thread void *unsafe_stack_start = nullptr;
 static __thread size_t unsafe_stack_size = 0;
 static __thread size_t unsafe_stack_guard = 0;
 
+using namespace __sanitizer;
+
 static inline void *unsafe_stack_alloc(size_t size, size_t guard) {
   CHECK_GE(size + guard, size);
   void *addr = MmapOrDie(size + guard, "unsafe_stack_alloc");