Added Basic Error codes, Tests and de-inliningmain

Error codes needs to be ingrated with the alloc module
Tests now have great coverage in the mem module (>75%).

Signed-off-by: Marc Pervaz Boocha <mboocha@sudomsg.xyz>

On branch main
Your branch is up to date with 'origin/main'.

Changes to be committed:
      modified:   include/alloc.h
      new file:   include/err.h
      modified:   include/mem.h
      modified:   include/meson.build
      modified:   readme.md
      modified:   src/alloc/free.c
      modified:   src/alloc/malloc.c
      new file:   src/err/errstr.c
      new file:   src/err/meson.build
      new file:   src/err/set_err.c
      modified:   src/mem/memccpy.c
      modified:   src/mem/memchr.c
      modified:   src/mem/memcmp.c
      modified:   src/mem/memcpy.c
      modified:   src/mem/memlen.c
      modified:   src/mem/memmem.c
      modified:   src/mem/memmove.c
      modified:   src/mem/memrchr.c
      modified:   src/mem/memrev.c
      modified:   src/mem/memset.c
      modified:   src/mem/memswap.c
      modified:   src/mem/memzero.c
      modified:   src/meson.build
      new file:   test/alloc/memdup.c
      modified:   test/alloc/meson.build
      new file:   test/mem/memccpy_nullnull.c
      new file:   test/mem/memchr.c
      new file:   test/mem/memchr_notfound.c
      new file:   test/mem/memcmp_diff.c
      new file:   test/mem/memcmp_prefix.c
      new file:   test/mem/memcmp_same.c
      new file:   test/mem/memcmp_samenull.c
      new file:   test/mem/memcmp_sing.c
      new file:   test/mem/memcpy_null_prefix.c
      new file:   test/mem/memcpy_null_same.c
      new file:   test/mem/memcpy_nullnull.c
      new file:   test/mem/memcpy_prefix.c
      new file:   test/mem/memcpy_same.c
      new file:   test/mem/memlen.c
      new file:   test/mem/memlen_overflow.c
      new file:   test/mem/memmove_backward.c
      new file:   test/mem/memmove_null_backward.c
      new file:   test/mem/memmove_null_overlap.c
      new file:   test/mem/memmove_null_prefix.c
      new file:   test/mem/memmove_null_same.c
      new file:   test/mem/memmove_null_sing.c
      new file:   test/mem/memmove_nullnull.c
      new file:   test/mem/memmove_overlap.c
      new file:   test/mem/memmove_prefix.c
      new file:   test/mem/memmove_same.c
      new file:   test/mem/memmove_sing.c
      new file:   test/mem/memrchr.c
      new file:   test/mem/memrchr_notfound.c
      new file:   test/mem/memrev.c
      new file:   test/mem/memset_null.c
      new file:   test/mem/memset_nullnull.c
      new file:   test/mem/memswap.c
      new file:   test/mem/memswap_null.c
      new file:   test/mem/memswap_same.c
      new file:   test/mem/memzero_null.c
      new file:   test/mem/memzero_nullnull.c
      modified:   test/mem/meson.build
      modified:   test/meson.build

1 files changed, 20 insertions, 2 deletions

diff --git a/src/mem/memmove.c b/src/mem/memmove.c
index b6c6b1e..abb5d41 100644
--- a/src/mem/memmove.c
+++ b/src/mem/memmove.c
@@ -6,6 +6,24 @@
 
 #include <mem.h>
 
-extern inline void *calt_memmove(void *dest, void const *src, size_t count);
-extern inline void *calt_memmove_null(void *dest, void const *src, size_t count);
+void *calt_memmove(void *dest, void const *src, size_t count) {
+	unsigned char *d = dest;
+	unsigned char const *s = src;
+
+	if (d > s) {
+		d += count;
+		s += count;
+		while (count-- > 0) {
+			*--d = *--s;
+		}
+	} else if (d < s) {
+		calt_memcpy(dest, src, count);
+	}
+
+	return dest;
+}
+
+void *calt_memmove_null(void *dest, void const *src, size_t count) {
+	return dest ? calt_memmove(dest, src, count) : NULL;
+}