From 3ef709502e47d7f350c021dd33bbeac83c5e5f5c Mon Sep 17 00:00:00 2001
From: Romain Goyet <romain@goyet.com>
Date: Sun, 30 Jul 2017 22:12:42 +0200
Subject: [PATCH] [liba] Add memcmp to strings.h

Change-Id: Ied4281e588d423e2b00dced10018a690455544d5
---
 liba/Makefile         |  1 +
 liba/include/string.h |  1 +
 liba/src/memcmp.c     | 14 ++++++++++++++
 3 files changed, 16 insertions(+)
 create mode 100644 liba/src/memcmp.c

diff --git a/liba/Makefile b/liba/Makefile
index 761b90772..7b949d82f 100644
--- a/liba/Makefile
+++ b/liba/Makefile
@@ -11,6 +11,7 @@ objs += $(addprefix liba/src/, \
   isinfd.o \
   isinff.o \
   malloc.o \
+  memcmp.o \
   memcpy.o \
   memmove.o \
   memset.o \
diff --git a/liba/include/string.h b/liba/include/string.h
index bc3852626..fedd91000 100644
--- a/liba/include/string.h
+++ b/liba/include/string.h
@@ -6,6 +6,7 @@
 
 LIBA_BEGIN_DECLS
 
+int memcmp(const void * s1, const void * s2, size_t n);
 void * memcpy(void * dst, const void * src, size_t n);
 void * memmove(void * dst, const void * src, size_t n);
 void * memset(void * b, int c, size_t len);
diff --git a/liba/src/memcmp.c b/liba/src/memcmp.c
new file mode 100644
index 000000000..86c9bbc81
--- /dev/null
+++ b/liba/src/memcmp.c
@@ -0,0 +1,14 @@
+#include <string.h>
+
+int memcmp(const void * s1, const void * s2, size_t n) {
+  char * source1 = (char *)s1;
+  char * source2 = (char *)s2;
+  while (n--) {
+    if (*source1 != *source2) {
+      return *source1 - *source2;
+    }
+    source1++;
+    source2++;
+  }
+  return 0;
+}