feat: Makefile, strlen and strcpy

Makefile

@@ -0,0 +1,45 @@
+NASM=nasm
+NASMFLAGS=-f elf64 -g -F dwarf
+AR=ar
+ARFLAGS=rcs
+CC=gcc
+CFLAGS=-Wall -g
+SRC_DIR=src
+OBJ_DIR=obj
+LIB_NAME=mylib
+STATIC_LIB=lib$(LIB_NAME).a
+SHARED_LIB=lib$(LIB_NAME).so
+
+SRCS=$(SRC_DIR)/ft_strlen.s \
+     $(SRC_DIR)/ft_strcpy.s
+
+OBJS=$(patsubst $(SRC_DIR)/%.s,$(OBJ_DIR)/%.o,$(SRCS))
+DEPS=$(OBJS:.o=.d)
+
+.PHONY: all clean dirs static shared
+
+all: dirs $(STATIC_LIB) $(SHARED_LIB)
+
+dirs:
+	@mkdir -p $(OBJ_DIR)
+
+$(OBJ_DIR)/%.o: $(SRC_DIR)/%.s
+	$(NASM) $(NASMFLAGS) $< -o $@
+
+$(STATIC_LIB): $(OBJS)
+	$(AR) $(ARFLAGS) $@ $^
+
+$(SHARED_LIB): $(OBJS)
+	$(CC) -shared -o $@ $^
+
+static: $(STATIC_LIB)
+
+shared: $(SHARED_LIB)
+
+test: test.c $(STATIC_LIB)
+	$(CC) $(CFLAGS) test.c -L. -l$(LIB_NAME) -o test -Wl,-rpath=.
+
+clean:
+	rm -rf $(OBJ_DIR) $(STATIC_LIB) $(SHARED_LIB) test
+
+-include $(DEPS)

src/ft_strcpy.s

@@ -0,0 +1,25 @@
+global ft_strcpy
+section .text
+
+; rdi = dest, rsi = src
+; rax = return value
+; should copy src in dest and return dest
+ft_strcpy:
+	mov		rax, rdi
+
+.loop:
+	mov		dl, byte [rsi]
+	test	dl, dl
+	je		.done
+
+	mov		byte [rdi], dl
+
+	inc		rsi
+	inc		rdi
+
+	jmp		.loop
+.done:
+
+	mov		byte [rdi], 0x0
+	mov		rdi, rax
+	ret

src/ft_strlen.s

@@ -0,0 +1,17 @@
+global ft_strlen
+section .text
+
+ft_strlen:
+	mov		rax, rdi
+
+.loop:
+	mov		dl, byte [rax]
+	test	dl, dl
+	je		.done
+
+	inc		rax
+
+	jmp		.loop
+.done:
+	sub		rax, rdi
+	ret

src/mylib.h

@@ -0,0 +1,17 @@
+#ifndef MYLIB_H
+#define MYLIB_H
+
+#include <string.h>
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+size_t	ft_strlen(char *str);
+char		*ft_strcpy(char *dest, const char *src);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif

test.c

@@ -0,0 +1,14 @@
+#include "src/mylib.h"
+#include <stdio.h>
+
+int
+main(void)
+{
+	char dest[16];
+	const char src[] = "Hello, world!\n";
+
+	printf("%s%s", ft_strcpy(dest, src), dest);
+	printf("%s", src);
+	printf("%ld\n", ft_strlen(dest));
+	printf("%ld\n", strlen(dest));
+}