zero initialize structs, begin porting my chip8 emulator

examples/chip8.zr

@@ -0,0 +1,96 @@
+// needs to be compiled with -m -C="-lraylib"
+extern InitWindow
+extern SetTargetFPS
+extern WindowShouldClose
+extern BeginDrawing
+extern ClearBackground
+extern DrawRectangle
+extern EndDrawing
+
+struct CHIP8
+    memory: ptr
+    pc: i64
+    stack: array
+    sp: i64
+    reg: array
+    I: i64
+    delay_timer: i64
+    sound_timer: i64
+    keyboard: array
+    display: ptr
+
+func chip8_create[] : CHIP8
+    let fonts: array = [0xf0, 0x90, 0x90, 0x90, 0xf0, 0x20, 0x60, 0x20, 0x20, 0x70, 0xf0, 0x10, 0xf0, 0x80, 0xf0, 0xf0, 0x10, 0xf0, 0x10, 0xf0, 0x90, 0x90, 0xf0, 0x10, 0x10, 0xf0, 0x80, 0xf0, 0x10, 0xf0, 0xf0, 0x80, 0xf0, 0x90, 0xf0, 0xf0, 0x10, 0x20, 0x40, 0x40, 0xf0, 0x90, 0xf0, 0x90, 0xf0, 0xf0, 0x90, 0xf0, 0x10, 0xf0, 0xf0, 0x90, 0xf0, 0x90, 0x90, 0xe0, 0x90, 0xe0, 0x90, 0xe0, 0xf0, 0x80, 0x80, 0x80, 0xf0, 0xe0, 0x90, 0x90, 0x90, 0xe0, 0xf0, 0x80, 0xf0, 0x80, 0xf0, 0xf0, 0x80, 0xf0, 0x80, 0x80]
+
+    let c: CHIP8 = new CHIP8
+    c->memory = mem.alloc(4096)
+    mem.zero(c->memory, 4096)
+    c->display = mem.alloc(64*32)
+    mem.zero(c->display, 64*32)
+
+    c->stack = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    c->reg = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+    c->keyboard = [0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0]
+
+    for i in 0..80
+        c->memory[i] = array.nth(fonts, i)
+    mem.free(fonts)
+
+    c->pc = 0x200
+    return c
+
+func chip8_disassemble[c: CHIP8, ins_count: i64] : void
+    return 0
+
+func chip8_step[c: CHIP8] : void
+    return 0
+
+func main[argc: i64, argv: ptr] : i64
+    let path: str = 0
+    let disassemble: bool = 0
+
+    for i in 1..argc
+        let arg: str = mem.read64(argv + i * 8)
+        if str.equal(arg, "-d")
+            disassemble = 1
+        else
+            path = arg
+    
+    if path == 0
+        io.println("Usage: chip8 -d <path>")
+        return 1
+    
+    let c: CHIP8 = chip8_create()
+
+    let bytes_size: ptr = 0
+    let bytes: ptr = io.read_binary_file(path, ^bytes_size)
+
+    for i in 0..bytes_size
+        c->memory[0x200 + i] = bytes[i]
+
+    if disassemble
+        chip8_disassemble(c, bytes_size / 2)
+        return 0
+    
+    InitWindow(640, 320, "CHIP-8")
+    SetTargetFPS(60)
+
+    while !WindowShouldClose()
+        if c->delay_timer > 0
+            c->delay_timer = c->delay_timer - 1
+        if c->sound_timer > 0
+            c->sound_timer = c->sound_timer - 1
+            // TODO: buzzer
+        
+        for i in 0..25
+            chip8_step(c)
+        
+        BeginDrawing()
+
+        ClearBackground(0xffffffff)
+        for y in 0..32
+            for x in 0..64
+                if c->display[x + y * 64] == 1
+                    DrawRectangle(x * 10, y * 10, 10, 10, 0x000000ff)
+
+        EndDrawing()

src/codegen_x86_64.rs

@@ -111,11 +111,6 @@ _builtin_read64:
     mov rax, qword [rdi]
     ret
 
-section .text._builtin_set8
-_builtin_set8:
-    mov [rdi], sil
-    ret
-
 section .text._builtin_set64
 _builtin_set64:
     mov [rdi], rsi
@@ -671,8 +666,14 @@ _builtin_environ:
             Expr::New(struct_name) => {
                 let struct_fields = &self.analyzer.structs[&struct_name.lexeme];
 
-                emit!(&mut self.output, "    mov rdi, {}", struct_fields.len() * 8);
+                let memory_size = struct_fields.len() * 8;
+                emit!(&mut self.output, "    mov rdi, {}", memory_size);
                 emit!(&mut self.output, "    call mem.alloc");
+                emit!(&mut self.output, "    push rax");
+                emit!(&mut self.output, "    mov rdi, rax");
+                emit!(&mut self.output, "    mov rsi, {}", memory_size);
+                emit!(&mut self.output, "    call mem.zero");
+                emit!(&mut self.output, "    pop rax");
             }
             Expr::MemberAccess { left, field } => {
                 let offset = self.get_field_offset(env, left, field)?;

src/std/std.zr

@@ -77,6 +77,7 @@ func io.read_line[]: str
     let buffer: str = mem.alloc(MAX_SIZE + 1)
     let n: i64 = _builtin_syscall(SYS_read, 0, buffer, MAX_SIZE)
     if n < 0
+        mem.free(buffer)
         return ""
     buffer[n] = 0
     return buffer
@@ -91,8 +92,22 @@ func io.read_file[path: str]: str
 
     let buffer: str = mem.alloc(size + 1)
     let n: i64 = _builtin_syscall(SYS_read, fd, buffer, size)
-    buffer[n] = 0
     _builtin_syscall(SYS_close, fd)
+    buffer[n] = 0
+    return buffer
+
+func io.read_binary_file[path: str, len_ptr: ptr] : ptr
+    let fd: i64 = _builtin_syscall(SYS_openat, -100, path, 0, 0)
+    if fd < 0
+        dbg.panic("failed to open file")
+    
+    let size: i64 = _builtin_syscall(SYS_lseek, fd, 0, 2)
+    _builtin_syscall(SYS_lseek, fd, 0, 0)
+
+    let buffer: ptr = mem.alloc(size)
+    _builtin_syscall(SYS_read, fd, buffer, size)
+    _builtin_syscall(SYS_close, fd)
+    mem.write64(len_ptr, size)
     return buffer
 
 func io.write_file[path: str, content: str] : void