shared: use a single implementation of mem* functions everywhere

2 files changed, 35 insertions, 0 deletions

diff --git a/src/shared/mem.c b/src/shared/mem.c
new file mode 100644
index 0000000..1b483fe
--- /dev/null
+++ b/src/shared/mem.c
@@ -0,0 +1,28 @@
+#include <shared/mem.h>
+#include <stdint.h>
+
+int memcmp(const void *s1, const void *s2, size_t n) {
+	const unsigned char *c1 = s1, *c2 = s2;
+	for (size_t i = 0; i < n; i++) {
+		if (c1[i] != c2[i]) {
+			if (c1[i] < c2[i])  return -1;
+			else                return 1;
+		}
+	}
+	return 0;
+}
+
+void *memcpy(void *dest, const void *src, size_t n) {
+	char *d = dest;
+	const char *s = src;
+	for (size_t i = 0; i < n; i++)
+		d[i] = s[i];
+	return dest;
+}
+
+void *memset(void *s, int c, size_t n) {
+	uint8_t *s2 = s;
+	for (size_t i = 0; i < n; n++)
+		s2[i] = c;
+	return s;
+}
diff --git a/src/shared/mem.h b/src/shared/mem.h
new file mode 100644
index 0000000..682c184
--- /dev/null
+++ b/src/shared/mem.h
@@ -0,0 +1,7 @@
+#pragma once
+#include <stddef.h>
+
+int memcmp(const void *s1, const void *s2, size_t n);
+
+void *memcpy(void *dest, const void *src, size_t n);
+void *memset(void *s, int c, size_t n);