Merge "fix __has_attribute in visual studio"
diff --git a/vpx_ports/mem.h b/vpx_ports/mem.h
index 737e9e0..4e90413 100644
--- a/vpx_ports/mem.h
+++ b/vpx_ports/mem.h
@@ -51,13 +51,19 @@
 #define VPX_WITH_ASAN 0
 #endif  // __has_feature(address_sanitizer) || defined(__SANITIZE_ADDRESS__)
 
+#if !defined(__has_attribute)
+#define __has_attribute(x) 0
+#endif  // !defined(__has_attribute)
+
 #if __has_attribute(uninitialized)
-// Attribute disables -ftrivial-auto-var-init=pattern for specific variables.
+// Attribute "uninitialized" disables -ftrivial-auto-var-init=pattern for
+// the specified variable.
+//
 // -ftrivial-auto-var-init is security risk mitigation feature, so attribute
 // should not be used "just in case", but only to fix real performance
-// bottlenecks when other approaches do not work. In general compiler is quite
-// effective eleminating unneeded initializations introduced by the flag, e.g.
-// when they are followed by actual initialization by a program.
+// bottlenecks when other approaches do not work. In general the compiler is
+// quite effective at eliminating unneeded initializations introduced by the
+// flag, e.g. when they are followed by actual initialization by a program.
 // However if compiler optimization fails and code refactoring is hard, the
 // attribute can be used as a workaround.
 #define VPX_UNINITIALIZED __attribute__((uninitialized))