[Buildroot] [PATCH next] package/uboot-tools: fix build with gcc 4.7

[Thomas Petazzoni]

The last bump of uboot-tools to 2019.01 broke the build on old build
machines that still use gcc 4.7 due to some C99 code that was added in
lib/crc16.c.

This commit solves that by adding a small patch (submitted upstream)
that avoids the C99 code.

Fixes:

  http://autobuild.buildroot.net/results/c88e4d94c21e247f6d190842dfa05ab797e8704d/

Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
---
 ...004-lib-crc16-use-non-C99-loop-style.patch | 41 +++++++++++++++++++
 1 file changed, 41 insertions(+)
 create mode 100644 package/uboot-tools/0004-lib-crc16-use-non-C99-loop-style.patch

diff --git a/package/uboot-tools/0004-lib-crc16-use-non-C99-loop-style.patch b/package/uboot-tools/0004-lib-crc16-use-non-C99-loop-style.patch
new file mode 100644
index 0000000000..1f86f8c099
--- /dev/null
+++ b/package/uboot-tools/0004-lib-crc16-use-non-C99-loop-style.patch
@@ -0,0 +1,41 @@
+From 17d603f2f3d8dcace5281b7bf5de0c6be61d0cc7 Mon Sep 17 00:00:00 2001
+From: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
+Date: Wed, 13 Feb 2019 22:54:45 +0100
+Subject: [PATCH] lib/crc16: use non-C99 loop style
+
+Commit 51c2345bd24837f9f67f16268da6dc71573f1325 ("Roll CRC16-CCITT
+into the hash infrastructure") has modified the crc16 code by adding a
+C99-style loop where the loop iterator is declared inside the for()
+statement. This breaks the build with old compiler such as gcc 4.7,
+that do not default to C99:
+
+./tools/../lib/crc16.c: In function 'crc16_ccitt':
+./tools/../lib/crc16.c:70:2: error: 'for' loop initial declarations are only allowed in C99 mode
+./tools/../lib/crc16.c:70:2: note: use option -std=c99 or -std=gnu99 to compile your code
+
+Switching to the regular coding style used in the rest of U-Boot
+allows to fix this build issue.
+
+Signed-off-by: Thomas Petazzoni <thomas.petazzoni at bootlin.com>
+---
+ lib/crc16.c | 4 +++-
+ 1 file changed, 3 insertions(+), 1 deletion(-)
+
+diff --git a/lib/crc16.c b/lib/crc16.c
+index f46ba727c9..89d2cff131 100644
+--- a/lib/crc16.c
++++ b/lib/crc16.c
+@@ -67,7 +67,9 @@ static const uint16_t crc16_tab[] = {
+ 
+ uint16_t crc16_ccitt(uint16_t cksum, const unsigned char *buf, int len)
+ {
+-	for (int i = 0;  i < len;  i++)
++	int i;
++
++	for (i = 0;  i < len;  i++)
+ 		cksum = crc16_tab[((cksum>>8) ^ *buf++) & 0xff] ^ (cksum << 8);
+ 
+ 	return cksum;
+-- 
+2.20.1
+
-- 
2.20.1