use preprocessor

Author: h908714124

README.md

@@ -10,6 +10,8 @@
 
 [Linux clobbered registers](https://stackoverflow.com/questions/69515893/when-does-linux-x86-64-syscall-clobber-r8-r9-and-r10)
 
+[Including header in assembly](https://stackoverflow.com/questions/60192138/including-header-file-in-assembly-file)
+
 ```
 /usr/include/asm-generic/fcntl.h
 ```

group3/Makefile

@@ -1,5 +1,8 @@
+CFLAGS += -x
+CFLAGS += assembler-with-cpp
+
 default:
-	$(CC) group3.s -g -o group3 -e main
+	$(CC) $(CFLAGS) group3.s -g -o group3 -e main
 
 clean:
 	@rm -f group3.o group3

group3/group3.s

@@ -1,9 +1,4 @@
-	.equ READ, 0
-	.equ CLOSE, 3
-	.equ OPEN, 2
-	.equ FSTAT, 5
-	.equ MMAP, 9
-	.equ MUNMAP, 11
+#include <sys/syscall.h>
 	.equ OFFSET_SIZE, 48		# struct stat
 
 	.data
@@ -40,7 +35,7 @@ file:
 get_memory:
 	enter
 	push_all
-	mov	$MMAP, %rax
+	mov	$SYS_mmap, %rax
 	mov	$0, %rdi		#addr
 	mov	$3, %rdx		#prot r=1 w=2
 	mov	file_size(%rip), %rsi 	#len
@@ -63,7 +58,7 @@ exit:
 open_file:
 	enter
 	push_all
-	mov	$OPEN, %rax
+	mov	$SYS_open, %rax
 	mov	$file, %rdi
 	mov	$0, %rsi
 	mov	$0644, %rdx
@@ -75,7 +70,7 @@ open_file:
 stat_file:
 	enter
 	push_all
-	mov	$FSTAT, %rax
+	mov	$SYS_fstat, %rax
 	mov	fh(%rip), %rdi
 	lea	st, %rsi
 	syscall
@@ -87,7 +82,7 @@ stat_file:
 init_file:
 	enter
 	push_all
-	mov	$READ, %rax
+	mov	$SYS_read, %rax
 	mov	fh(%rip), %rdi
 	mov	inbuf(%rip), %rsi
 	mov	file_size(%rip), %rdx
@@ -144,7 +139,7 @@ read_line_done:
 close:
 	enter
 	push_all
-	mov	$CLOSE, %rax
+	mov	$SYS_close, %rax
 	mov	fh, %rdi
 	syscall
 	pop_all
@@ -153,25 +148,25 @@ close:
 munmap:
 	enter
 	push_all
-	mov	$MUNMAP, %rax
+	mov	$SYS_munmap, %rax
 	mov	inbuf, %rdi
 	mov	file_size(%rip), %rsi
 	syscall
-	mov	$MUNMAP, %rax
+	mov	$SYS_munmap, %rax
 	mov	out, %rdi
 	mov	file_size(%rip), %rsi
 	syscall
 	pop_all
 	return
 
 
-# tmp = '___'
-# with open('data.txt') as file:
-#     while line := file.readline():
-#         if not line.startswith(tmp):
-#             print(line[:3])
-#         tmp = line[:3]
-#         print('\t' + line.rstrip()[3:])
+#. tmp = '___'
+#. with open('data.txt') as file:
+#.     while line := file.readline():
+#.         if not line.startswith(tmp):
+#.             print(line[:3])
+#.         tmp = line[:3]
+#.         print('\t' + line.rstrip()[3:])
 print_lines:
 	enter
 	sub	$128, %rsp

print_int/Makefile

@@ -1,17 +1,20 @@
+CFLAGS += -x
+CFLAGS += assembler-with-cpp
+
 print_int:
-	$(CC) main.s -o print_int
+	$(CC) $(CFLAGS) main.s -o print_int
 
 check: print_int
 	./print_int | md5sum | grep -q ^3cca2fa && printf "\033[1;32m[OK]\033[0m\n"
 
 write:
-	$(CC) write.s -o write
+	$(CC) $(CFLAGS) write.s -o write
 
 check_write: write
 	./write | grep -q '^ABC$$' && printf "\033[1;32m[OK]\033[0m\n"
 
 strcmp:
-	$(CC) strcmp.s -o strcmp
+	$(CC) $(CFLAGS) strcmp.s -o strcmp
 
 check_strcmp: strcmp
 	./strcmp | md5sum | grep -q ^00350de && printf "\033[1;32m[OK]\033[0m\n"

print_int/main.s

@@ -1,3 +1,4 @@
+#include <sys/syscall.h>
 	.text
 	.globl main
 
@@ -44,6 +45,6 @@ main:
 	call	exit
 
 exit:
-	movq	$EXIT, %rax
-	movq	$0, %rdi
+	mov	$SYS_exit_group, %rax
+	mov	$0, %rdi
 	syscall

print_int/print_int.c

@@ -0,0 +1,33 @@
+#include <stdint.h>
+#include <stdio.h>
+#include <unistd.h>
+#include <sys/syscall.h>
+#include <sys/types.h>
+
+const char *format = "0x%.*s\n";
+
+void print_int(uint64_t n)
+{
+	char tmp[16], output[16];
+	uint8_t count = 0;
+	do {
+		char c = 0xf & n;
+		c += 0x30;		// c now contains ascii "0"-"9"
+		if (c > 0x39) {
+			c += 0x27;	// adjust for ascii "a"-"f"
+		}
+		tmp[count++] = c;
+		n = n >> 4;
+	} while(n != 0);
+	for (uint8_t i = 0; i < count; i++) {
+		output[i] = tmp[count - i - 1];
+	}
+	printf(format, count, output);
+}
+
+int main(int argc, char *argv[])
+{
+	print_int(0x9084a412);
+	print_int(0);
+	return 0;
+}