From: Adenilson Cavalcanti <cavalcantii@chromium.org>
Date: Mon, 29 Jul 2024 23:37:41 +0000 (-0700)
Subject: [zstd][android] Fix build with NDK r27
X-Git-Tag: v1.5.7^2~100^2
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=refs%2Fpull%2F4107%2Fhead;p=thirdparty%2Fzstd.git

[zstd][android] Fix build with NDK r27

The NDK cross compiler declares the target as __linux (which is
not technically incorrect), which triggers the enablement of _GNU_SOURCE
in the newly added code that requires the presence of qsort_r() used
in the COVER dictionary code.

Even though the NDK uses llvm/libc, it doesn't declare qsort_r()
in the stdlib.h header.

The build fix is to only activate the _GNU_SOURCE macro if the OS is
*not* Android, as then we will fallback to the C90 compliant code.

This patch should solve the reported issue number #4103.
---

diff --git a/lib/common/zstd_deps.h b/lib/common/zstd_deps.h
index f41a973c3..8a9c7cc53 100644
--- a/lib/common/zstd_deps.h
+++ b/lib/common/zstd_deps.h
@@ -31,7 +31,7 @@
  */
 #if defined(__linux) || defined(__linux__) || defined(linux) || defined(__gnu_linux__) || \
     defined(__CYGWIN__) || defined(__MSYS__)
-#if !defined(_GNU_SOURCE)
+#if !defined(_GNU_SOURCE) && !defined(__ANDROID__) /* NDK doesn't ship qsort_r(). */
 #define _GNU_SOURCE
 #endif
 #endif
diff --git a/lib/dictBuilder/cover.c b/lib/dictBuilder/cover.c
index 386a4d572..2ef33c73e 100644
--- a/lib/dictBuilder/cover.c
+++ b/lib/dictBuilder/cover.c
@@ -24,7 +24,7 @@
 /* qsort_r is an extension. */
 #if defined(__linux) || defined(__linux__) || defined(linux) || defined(__gnu_linux__) || \
     defined(__CYGWIN__) || defined(__MSYS__)
-#if !defined(_GNU_SOURCE)
+#if !defined(_GNU_SOURCE) && !defined(__ANDROID__) /* NDK doesn't ship qsort_r(). */
 #define _GNU_SOURCE
 #endif
 #endif