zero initialize structs, begin porting my chip8 emulator

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

@@ -77,11 +77,12 @@ 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
 
-func io.read_file[path: str]: str
+func io.read_file[path: str] : str
     let fd: i64 = _builtin_syscall(SYS_openat, -100, path, 0, 0)
     if fd <= 0
         dbg.panic("failed to open file")
@@ -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