From 2b03bc5645304d9160f0778582151a406f79d62d Mon Sep 17 00:00:00 2001
From: flysand7 <thebumboni@gmail.com>
Date: Tue, 12 Sep 2023 03:03:06 +1100
Subject: [PATCH] add str/memcpy functions

---
 cia.c                   |  3 +++
 include/string.h        | 13 ++++++++++++-
 src/stdlib-string/mem.c | 40 ++++++++++++++++++++++++++++++++++++++++
 src/stdlib-string/str.c | 26 ++++++++++++++++++++++++++
 tests/mm_seq_cst.c      | 12 ++----------
 5 files changed, 83 insertions(+), 11 deletions(-)
 create mode 100644 src/stdlib-string/mem.c
 create mode 100644 src/stdlib-string/str.c

diff --git a/cia.c b/cia.c
index bff0250..4f99121 100644
--- a/cia.c
+++ b/cia.c
@@ -32,3 +32,6 @@
 // Module stdlib_file
 #include "src/stdlib-file/file.c"
 
+// Module stdlib_string
+#include "src/stdlib-string/mem.c"
+#include "src/stdlib-string/str.c"
diff --git a/include/string.h b/include/string.h
index 55103d5..11edb3e 100644
--- a/include/string.h
+++ b/include/string.h
@@ -1,3 +1,14 @@
 
-void memset(void *dest, int ch, size_t length);
+#pragma once
+
+#include <cia/def.h>
+
+void *memcpy(void *restrict dst, void const *restrict src, size_t count);
+void *memccpy(void *restrict dst, void const *restrict src, int c, size_t count);
+void *memmove(void *dst, const void *src, size_t count)
+
+char *strcpy(char *restrict dst, char const *restrict src);
+char *strncpy(char *restrict dst, char const *restrict src, size_t count);
+
+void memset(void *dst, int ch, size_t length);
 int _wcsicmp(uint16_t *s1, uint16_t *s2);
diff --git a/src/stdlib-string/mem.c b/src/stdlib-string/mem.c
new file mode 100644
index 0000000..776e80b
--- /dev/null
+++ b/src/stdlib-string/mem.c
@@ -0,0 +1,40 @@
+
+void *memcpy(void *restrict dst, void const *restrict src, size_t count) {
+    u8 *restrict dst_bytes = dst;
+    u8 const *restrict src_bytes = src;
+    for(size_t i = 0; i < count; ++i) {
+        dst_bytes[i] = src_bytes[i];
+    }
+    return dst_bytes;
+}
+
+void *memccpy(void *restrict dst, void const *restrict src, int c, size_t count) {
+    u8 *restrict dst_bytes = dst;
+    u8 const *restrict src_bytes = src;
+    for(size_t i = 0; i < count; ++i) {
+        dst_bytes[i] = src_bytes[i];
+        if(src_bytes[i] == c) {
+            return (void *)&src[i+1];
+        }
+    }
+    return NULL;
+}
+
+void *memmove(void *dst, const void *src, size_t count) {
+    if(dst == src) {
+        return dst;
+    }
+    u8 *dst_bytes = dst;
+    u8 const *src_bytes = src;
+    if(dst < src) {
+        for(size_t i = 0; i < count; ++i) {
+            dst_bytes[i] = src_bytes[i];
+        }
+    }
+    else {
+        for(size_t i = count-1; i-- != 0; ) {
+            dst_bytes[i] = src_bytes[i];
+        }
+    }
+    return dst_bytes;
+}
diff --git a/src/stdlib-string/str.c b/src/stdlib-string/str.c
new file mode 100644
index 0000000..99f7dfe
--- /dev/null
+++ b/src/stdlib-string/str.c
@@ -0,0 +1,26 @@
+
+char *strcpy(char *restrict dst, char const *restrict src) {
+    i64 str_len = 0;
+    for(i64 i = 0; src[i] != 0; ++i) {
+        dst[i] = src[i];
+        str_len += 1;
+    }
+    dst[str_len] = 0;
+    return dst;
+}
+
+char *strncpy(char *restrict dst, char const *restrict src, size_t count) {
+    i64 str_len = 0;
+    for(i64 i = 0; i < count; ++i) {
+        if(src[i] == 0) {
+            break;
+        }
+        dst[i] = src[i];
+        str_len += 1;
+    }
+    for(i64 i = str_len; i < count; ++i) {
+        dst[i] = 0;
+    }
+    return dst;
+}
+
diff --git a/tests/mm_seq_cst.c b/tests/mm_seq_cst.c
index 0d0260e..c1c2130 100644
--- a/tests/mm_seq_cst.c
+++ b/tests/mm_seq_cst.c
@@ -12,7 +12,7 @@
 #endif
 
 // Scheduler on linux has too coarse granularity
-// to allow a thread to a very tiny bit of work
+// to allow a thread to kind of a lot of work
 // before switching to another thread. If we
 // introduce an arbitrary delay, the threads will
 // be able to be run in a random order better.
@@ -100,15 +100,7 @@ int main() {
     // Check to see the cnt variable
     int result = atomic_load_explicit(&g_shared_state.cnt, memory_order_relaxed);
     if(result == 0) {
-        char msg[] = "Result was 0\n";
-        fwrite(msg, 1, sizeof msg, stdout);
-    }
-    else if(result == 1) {
-        char msg[] = "Result was 1\n";
-        fwrite(msg, 1, sizeof msg, stdout);
-    }
-    else {
-        char msg[] = "Result was 2\n";
+        char msg[] = "This shouldn't happen in sequentially-consistent model!\n";
         fwrite(msg, 1, sizeof msg, stdout);
     }
     return 0;