From f854e3dc2967106e92fcd9f61c67b2083e62cf8c Mon Sep 17 00:00:00 2001
From: Mahmoud Al-Qudsi <mqudsi@neosmart.net>
Date: Thu, 5 Sep 2019 23:11:59 -0500
Subject: [PATCH] Try fixing __has_attribute errors on Travis macOS

---
 src/fallback.h | 26 +++++++++++++-------------
 1 file changed, 13 insertions(+), 13 deletions(-)

diff --git a/src/fallback.h b/src/fallback.h
index 62b8dc8b7..c84987d61 100644
--- a/src/fallback.h
+++ b/src/fallback.h
@@ -66,18 +66,18 @@ char *tparm_solaris_kludge(char *str, long p1 = 0, long p2 = 0, long p3 = 0, lon
                            long p5 = 0, long p6 = 0, long p7 = 0, long p8 = 0, long p9 = 0);
 #endif
 
-/// On OS X, use weak linking for wcsdup and wcscasecmp. Weak linking allows you to call the
-/// function only if it exists at runtime. You can detect it by testing the function pointer against
-/// NULL. To avoid making the callers do that, redefine wcsdup to wcsdup_use_weak, and likewise with
-/// wcscasecmp. This lets us use the same binary on SnowLeopard (10.6) and Lion+ (10.7), even though
-/// these functions only exist on 10.7+.
-///
-/// On other platforms, use what's detected at build time.
+// On OS X, use weak linking for wcsdup and wcscasecmp. Weak linking allows you to call the
+// function only if it exists at runtime. You can detect it by testing the function pointer against
+// NULL. To avoid making the callers do that, redefine wcsdup to wcsdup_use_weak, and likewise with
+// wcscasecmp. This lets us use the same binary on SnowLeopard (10.6) and Lion+ (10.7), even though
+// these functions only exist on 10.7+.
+//
+// On other platforms, use what's detected at build time.
 #if __APPLE__
-#if __DARWIN_C_LEVEL >= 200809L && __has_attribute(clang::weak_import)
-// We have to explicitly redeclare these as weak,
-// since we are forced to set the MIN_REQUIRED availability macro to 10.7
-// to use libc++, which in turn exposes these as strong
+// Avoid warnings about unknown `clang::weak_import` attribute (e.g. GCC 8.2.0 on macOS 10.10)
+#if __DARWIN_C_LEVEL >= 200809L && __clang__ && __has_attribute(weak_import)
+// We have to explicitly redeclare these as weak, since we are forced to set the MIN_REQUIRED
+// availability macro to 10.7 to use libc++, which in turn exposes these as strong
 [[clang::weak_import]] wchar_t *wcsdup(const wchar_t *);
 [[clang::weak_import]] int wcscasecmp(const wchar_t *, const wchar_t *);
 [[clang::weak_import]] int wcsncasecmp(const wchar_t *, const wchar_t *, size_t n);
@@ -92,8 +92,8 @@ wchar_t *wcsdup(const wchar_t *in);
 int wcscasecmp(const wchar_t *a, const wchar_t *b);
 int wcsncasecmp(const wchar_t *s1, const wchar_t *s2, size_t n);
 wchar_t *wcsndup(const wchar_t *in, size_t c);
-#endif
-#else  //__APPLE__
+#endif // clang::weak_import
+#else  // __APPLE__
 
 /// These functions are missing from Solaris 10, and only accessible from
 /// Solaris 11 in the std:: namespace.