Provide default implementations for sanitizer interface functions

Summary:
Adds a few default implementations for weak
interface functions on platforms where weak hooks are not supported.

Reviewers: eugenis, samsonov, timurrrr

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28201

llvm-svn: 291313

compiler-rt/lib/lsan/lsan_allocator.cc

@@ -258,4 +258,17 @@ SANITIZER_INTERFACE_ATTRIBUTE
 uptr __sanitizer_get_allocated_size(const void *p) {
   return GetMallocUsableSize(p);
 }
+
+#if !SANITIZER_SUPPORTS_WEAK_HOOKS
+// Provide default (no-op) implementation of malloc hooks.
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+void __sanitizer_malloc_hook(void *ptr, uptr size) {
+  (void)ptr;
+  (void)size;
+}
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+void __sanitizer_free_hook(void *ptr) {
+  (void)ptr;
+}
+#endif
 } // extern "C"

compiler-rt/lib/lsan/lsan_common.cc

@@ -758,5 +758,10 @@ SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
 int __lsan_is_turned_off() {
   return 0;
 }
+
+SANITIZER_INTERFACE_ATTRIBUTE SANITIZER_WEAK_ATTRIBUTE
+const char *__lsan_default_suppressions() {
+  return "";
+}
 #endif
 } // extern "C"