From: Yann Collet <cyan@fb.com>
Date: Sun, 27 Aug 2023 23:12:06 +0000 (-0700)
Subject: add include guards
X-Git-Tag: v1.5.6^2~54^2~4
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=b69d06a8102f0e04cde0bda2e34984099a0dfba4;p=thirdparty%2Fzstd.git

add include guards

alleviate risks of double inclusion (typically via transitive includes)
---

diff --git a/lib/libzstd.mk b/lib/libzstd.mk
index 2c47ecdfa..ce6e11375 100644
--- a/lib/libzstd.mk
+++ b/lib/libzstd.mk
@@ -8,6 +8,10 @@
 # You may select, at your option, one of the above-listed licenses.
 # ################################################################
 
+# Ensure the file is not included twice
+ifndef LIBZSTD_MK_INCLUDED
+LIBZSTD_MK_INCLUDED := 1
+
 ##################################################################
 # Input Variables
 ##################################################################
@@ -223,3 +227,5 @@ endif # BUILD_DIR
 ZSTD_SUBDIR := $(LIBZSTD)/common $(LIBZSTD)/compress $(LIBZSTD)/decompress $(LIBZSTD)/dictBuilder $(LIBZSTD)/legacy $(LIBZSTD)/deprecated
 vpath %.c $(ZSTD_SUBDIR)
 vpath %.S $(ZSTD_SUBDIR)
+
+endif # LIBZSTD_MK_INCLUDED