Address comments.

Author: lntue

libc/src/__support/common.h

@@ -32,7 +32,7 @@
 #define LLVM_LIBC_EMPTY
 
 #define GET_SECOND(first, second, ...) second
-#define EXPAND_THEN_SECOND(name) GET_SECOND(name, LLVM_LIBC_EMPTY, )
+#define EXPAND_THEN_SECOND(name) GET_SECOND(name, LLVM_LIBC_EMPTY)
 
 #define LLVM_LIBC_ATTR(name) EXPAND_THEN_SECOND(LLVM_LIBC_FUNCTION_ATTR_##name)
 

utils/bazel/llvm-project-overlay/libc/libc_build_rules.bzl

@@ -114,16 +114,13 @@ def libc_function(
 
     # This second target is the llvm libc C function with either a default or hidden visibility.
     # All other functions are hidden.
-    global_func_attrs = [
-        "[[gnu::visibility(\"default\")]]",
-    ]
     func_attrs = [
-        "LLVM_LIBC_FUNCTION_ATTR_" + name + "=\"LLVM_LIBC_EMPTY, [[gnu::weak]]\"",
+        "LLVM_LIBC_FUNCTION_ATTR_" + name + "='LLVM_LIBC_EMPTY, [[gnu::weak]]'",
     ] if weak else []
 
     local_defines = (local_defines
                     + ["LIBC_COPT_PUBLIC_PACKAGING"]
-                    + ["LLVM_LIBC_FUNCTION_ATTR='%s'" % " ".join(global_func_attrs)]
+                    + ["LLVM_LIBC_FUNCTION_ATTR='[[gnu::visibility(\"default\")]]'"]
                     + func_attrs)
     _libc_library(
         name = name,