1 // Copyright 2012-2014 The Rust Project Developers. See the COPYRIGHT
2 // file at the top-level directory of this distribution and at
3 // http://rust-lang.org/COPYRIGHT.
5 // Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
6 // http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
7 // <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
8 // option. This file may not be copied, modified, or distributed
9 // except according to those terms.
13 More runtime type reflection
18 use std::intrinsics::{Disr, Opaque, TyDesc, TyVisitor, get_tydesc, visit_tydesc};
24 use reflect::{MovePtr, align};
26 macro_rules! try( ($me:expr, $e:expr) => (
29 Err(e) => { $me.last_err = Some(e); return false; }
36 fn write_repr(&self, writer: &mut io::Writer) -> io::IoResult<()>;
40 fn write_repr(&self, writer: &mut io::Writer) -> io::IoResult<()> {
41 writer.write("()".as_bytes())
46 fn write_repr(&self, writer: &mut io::Writer) -> io::IoResult<()> {
47 let s = if *self { "true" } else { "false" };
48 writer.write(s.as_bytes())
53 fn write_repr(&self, writer: &mut io::Writer) -> io::IoResult<()> {
54 write!(writer, "{}", *self)
58 macro_rules! int_repr(($ty:ident, $suffix:expr) => (impl Repr for $ty {
59 fn write_repr(&self, writer: &mut io::Writer) -> io::IoResult<()> {
60 write!(writer, "{}{}", *self, $suffix)
74 macro_rules! num_repr(($ty:ident, $suffix:expr) => (impl Repr for $ty {
75 fn write_repr(&self, writer: &mut io::Writer) -> io::IoResult<()> {
76 let s = self.to_str();
77 writer.write(s.as_bytes()).and_then(|()| {
83 num_repr!(f32, b"f32")
84 num_repr!(f64, b"f64")
86 // New implementation using reflect::MovePtr
94 pub struct ReprVisitor<'a> {
97 var_stk: Vec<VariantState>,
98 writer: &'a mut io::Writer,
99 last_err: Option<io::IoError>,
102 impl<'a> MovePtr for ReprVisitor<'a> {
104 fn move_ptr(&mut self, adjustment: |*u8| -> *u8) {
105 self.ptr = adjustment(self.ptr);
107 fn push_ptr(&mut self) {
108 self.ptr_stk.push(self.ptr);
110 fn pop_ptr(&mut self) {
111 self.ptr = self.ptr_stk.pop().unwrap();
115 impl<'a> ReprVisitor<'a> {
116 // Various helpers for the TyVisitor impl
117 pub fn new(ptr: *u8, writer: &'a mut io::Writer) -> ReprVisitor<'a> {
128 pub fn get<T>(&mut self, f: |&mut ReprVisitor, &T| -> bool) -> bool {
131 f(self, mem::transmute::<*u8,&T>(ptr))
136 pub fn visit_inner(&mut self, inner: *TyDesc) -> bool {
138 self.visit_ptr_inner(ptr, inner)
142 pub fn visit_ptr_inner(&mut self, ptr: *u8, inner: *TyDesc) -> bool {
144 let u = ReprVisitor::new(ptr, mem::transmute_copy(&self.writer));
145 let mut v = reflect::MovePtrAdaptor::new(u);
146 // Obviously this should not be a thing, but blame #8401 for now
147 visit_tydesc(inner, &mut v as &mut TyVisitor);
148 match v.unwrap().last_err {
150 self.last_err = Some(e);
159 pub fn write<T:Repr>(&mut self) -> bool {
160 self.get(|this, v:&T| {
161 try!(this, v.write_repr(this.writer));
166 pub fn write_escaped_slice(&mut self, slice: &str) -> bool {
167 try!(self, self.writer.write(['"' as u8]));
168 for ch in slice.chars() {
169 if !self.write_escaped_char(ch, true) { return false }
171 try!(self, self.writer.write(['"' as u8]));
175 pub fn write_mut_qualifier(&mut self, mtbl: uint) -> bool {
177 try!(self, self.writer.write("mut ".as_bytes()));
178 } else if mtbl == 1 {
179 // skip, this is ast::m_imm
181 fail!("invalid mutability value");
186 pub fn write_vec_range(&mut self, ptr: *(), len: uint, inner: *TyDesc) -> bool {
187 let mut p = ptr as *u8;
188 let (sz, al) = unsafe { ((*inner).size, (*inner).align) };
189 try!(self, self.writer.write(['[' as u8]));
190 let mut first = true;
192 // unit structs have 0 size, and don't loop forever.
193 let dec = if sz == 0 {1} else {sz};
198 try!(self, self.writer.write(", ".as_bytes()));
200 self.visit_ptr_inner(p as *u8, inner);
201 p = align(unsafe { p.offset(sz as int) as uint }, al) as *u8;
204 try!(self, self.writer.write([']' as u8]));
208 fn write_escaped_char(&mut self, ch: char, is_str: bool) -> bool {
209 try!(self, match ch {
210 '\t' => self.writer.write("\\t".as_bytes()),
211 '\r' => self.writer.write("\\r".as_bytes()),
212 '\n' => self.writer.write("\\n".as_bytes()),
213 '\\' => self.writer.write("\\\\".as_bytes()),
216 self.writer.write("'".as_bytes())
218 self.writer.write("\\'".as_bytes())
223 self.writer.write("\\\"".as_bytes())
225 self.writer.write("\"".as_bytes())
228 '\x20'..'\x7e' => self.writer.write([ch as u8]),
230 char::escape_unicode(ch, |c| {
231 let _ = self.writer.write([c as u8]);
240 impl<'a> TyVisitor for ReprVisitor<'a> {
241 fn visit_bot(&mut self) -> bool {
242 try!(self, self.writer.write("!".as_bytes()));
245 fn visit_nil(&mut self) -> bool { self.write::<()>() }
246 fn visit_bool(&mut self) -> bool { self.write::<bool>() }
247 fn visit_int(&mut self) -> bool { self.write::<int>() }
248 fn visit_i8(&mut self) -> bool { self.write::<i8>() }
249 fn visit_i16(&mut self) -> bool { self.write::<i16>() }
250 fn visit_i32(&mut self) -> bool { self.write::<i32>() }
251 fn visit_i64(&mut self) -> bool { self.write::<i64>() }
253 fn visit_uint(&mut self) -> bool { self.write::<uint>() }
254 fn visit_u8(&mut self) -> bool { self.write::<u8>() }
255 fn visit_u16(&mut self) -> bool { self.write::<u16>() }
256 fn visit_u32(&mut self) -> bool { self.write::<u32>() }
257 fn visit_u64(&mut self) -> bool { self.write::<u64>() }
259 fn visit_f32(&mut self) -> bool { self.write::<f32>() }
260 fn visit_f64(&mut self) -> bool { self.write::<f64>() }
262 fn visit_char(&mut self) -> bool {
263 self.get::<char>(|this, &ch| {
264 try!(this, this.writer.write(['\'' as u8]));
265 if !this.write_escaped_char(ch, false) { return false }
266 try!(this, this.writer.write(['\'' as u8]));
271 fn visit_estr_slice(&mut self) -> bool {
272 self.get::<&str>(|this, s| this.write_escaped_slice(*s))
275 // Type no longer exists, vestigial function.
276 fn visit_estr_fixed(&mut self, _n: uint, _sz: uint,
277 _align: uint) -> bool { fail!(); }
279 fn visit_box(&mut self, mtbl: uint, inner: *TyDesc) -> bool {
280 try!(self, self.writer.write("box(GC) ".as_bytes()));
281 self.write_mut_qualifier(mtbl);
282 self.get::<&raw::Box<()>>(|this, b| {
283 let p = &b.data as *() as *u8;
284 this.visit_ptr_inner(p, inner)
288 fn visit_uniq(&mut self, _mtbl: uint, inner: *TyDesc) -> bool {
289 try!(self, self.writer.write("box ".as_bytes()));
290 self.get::<*u8>(|this, b| {
291 this.visit_ptr_inner(*b, inner)
295 fn visit_ptr(&mut self, mtbl: uint, _inner: *TyDesc) -> bool {
296 self.get::<*u8>(|this, p| {
297 try!(this, write!(this.writer, "({} as *", *p));
298 this.write_mut_qualifier(mtbl);
299 try!(this, this.writer.write("())".as_bytes()));
304 fn visit_rptr(&mut self, mtbl: uint, inner: *TyDesc) -> bool {
305 try!(self, self.writer.write(['&' as u8]));
306 self.write_mut_qualifier(mtbl);
307 self.get::<*u8>(|this, p| {
308 this.visit_ptr_inner(*p, inner)
312 fn visit_evec_slice(&mut self, mtbl: uint, inner: *TyDesc) -> bool {
313 self.get::<raw::Slice<()>>(|this, s| {
314 try!(this, this.writer.write(['&' as u8]));
315 this.write_mut_qualifier(mtbl);
317 if (*inner).size == 0 { 1 } else { (*inner).size }
319 this.write_vec_range(s.data, s.len * size, inner)
323 fn visit_evec_fixed(&mut self, n: uint, sz: uint, _align: uint,
324 _: uint, inner: *TyDesc) -> bool {
325 let assumed_size = if sz == 0 { n } else { sz };
326 self.get::<()>(|this, b| {
327 this.write_vec_range(b, assumed_size, inner)
331 fn visit_enter_rec(&mut self, _n_fields: uint,
332 _sz: uint, _align: uint) -> bool {
333 try!(self, self.writer.write(['{' as u8]));
337 fn visit_rec_field(&mut self, i: uint, name: &str,
338 mtbl: uint, inner: *TyDesc) -> bool {
340 try!(self, self.writer.write(", ".as_bytes()));
342 self.write_mut_qualifier(mtbl);
343 try!(self, self.writer.write(name.as_bytes()));
344 try!(self, self.writer.write(": ".as_bytes()));
345 self.visit_inner(inner);
349 fn visit_leave_rec(&mut self, _n_fields: uint,
350 _sz: uint, _align: uint) -> bool {
351 try!(self, self.writer.write(['}' as u8]));
355 fn visit_enter_class(&mut self, name: &str, named_fields: bool, n_fields: uint,
356 _sz: uint, _align: uint) -> bool {
357 try!(self, self.writer.write(name.as_bytes()));
360 try!(self, self.writer.write(['{' as u8]));
362 try!(self, self.writer.write(['(' as u8]));
368 fn visit_class_field(&mut self, i: uint, name: &str, named: bool,
369 _mtbl: uint, inner: *TyDesc) -> bool {
371 try!(self, self.writer.write(", ".as_bytes()));
374 try!(self, self.writer.write(name.as_bytes()));
375 try!(self, self.writer.write(": ".as_bytes()));
377 self.visit_inner(inner);
381 fn visit_leave_class(&mut self, _name: &str, named_fields: bool, n_fields: uint,
382 _sz: uint, _align: uint) -> bool {
385 try!(self, self.writer.write(['}' as u8]));
387 try!(self, self.writer.write([')' as u8]));
393 fn visit_enter_tup(&mut self, _n_fields: uint,
394 _sz: uint, _align: uint) -> bool {
395 try!(self, self.writer.write(['(' as u8]));
399 fn visit_tup_field(&mut self, i: uint, inner: *TyDesc) -> bool {
401 try!(self, self.writer.write(", ".as_bytes()));
403 self.visit_inner(inner);
407 fn visit_leave_tup(&mut self, _n_fields: uint,
408 _sz: uint, _align: uint) -> bool {
410 try!(self, self.writer.write([',' as u8]));
412 try!(self, self.writer.write([')' as u8]));
416 fn visit_enter_enum(&mut self,
418 get_disr: unsafe extern fn(ptr: *Opaque) -> Disr,
420 _align: uint) -> bool {
422 get_disr(mem::transmute(self.ptr))
424 self.var_stk.push(SearchingFor(disr));
428 fn visit_enter_enum_variant(&mut self, _variant: uint,
431 name: &str) -> bool {
432 let mut write = false;
433 match self.var_stk.pop().unwrap() {
434 SearchingFor(sought) => {
435 if disr_val == sought {
436 self.var_stk.push(Matched);
439 self.var_stk.push(SearchingFor(sought));
442 Matched | AlreadyFound => {
443 self.var_stk.push(AlreadyFound);
448 try!(self, self.writer.write(name.as_bytes()));
450 try!(self, self.writer.write(['(' as u8]));
456 fn visit_enum_variant_field(&mut self,
461 match *self.var_stk.get(self.var_stk.len() - 1) {
464 try!(self, self.writer.write(", ".as_bytes()));
466 if ! self.visit_inner(inner) {
475 fn visit_leave_enum_variant(&mut self, _variant: uint,
478 _name: &str) -> bool {
479 match *self.var_stk.get(self.var_stk.len() - 1) {
482 try!(self, self.writer.write([')' as u8]));
490 fn visit_leave_enum(&mut self,
492 _get_disr: unsafe extern fn(ptr: *Opaque) -> Disr,
496 match self.var_stk.pop().unwrap() {
497 SearchingFor(..) => fail!("enum value matched no variant"),
502 fn visit_enter_fn(&mut self, _purity: uint, _proto: uint,
503 _n_inputs: uint, _retstyle: uint) -> bool {
504 try!(self, self.writer.write("fn(".as_bytes()));
508 fn visit_fn_input(&mut self, i: uint, _mode: uint, inner: *TyDesc) -> bool {
510 try!(self, self.writer.write(", ".as_bytes()));
512 let name = unsafe { (*inner).name };
513 try!(self, self.writer.write(name.as_bytes()));
517 fn visit_fn_output(&mut self, _retstyle: uint, variadic: bool,
518 inner: *TyDesc) -> bool {
520 try!(self, self.writer.write(", ...".as_bytes()));
522 try!(self, self.writer.write(")".as_bytes()));
523 let name = unsafe { (*inner).name };
525 try!(self, self.writer.write(" -> ".as_bytes()));
526 try!(self, self.writer.write(name.as_bytes()));
531 fn visit_leave_fn(&mut self, _purity: uint, _proto: uint,
532 _n_inputs: uint, _retstyle: uint) -> bool { true }
535 fn visit_trait(&mut self, name: &str) -> bool {
536 try!(self, self.writer.write(name.as_bytes()));
540 fn visit_param(&mut self, _i: uint) -> bool { true }
541 fn visit_self(&mut self) -> bool { true }
544 pub fn write_repr<T>(writer: &mut io::Writer, object: &T) -> io::IoResult<()> {
546 let ptr = object as *T as *u8;
547 let tydesc = get_tydesc::<T>();
548 let u = ReprVisitor::new(ptr, writer);
549 let mut v = reflect::MovePtrAdaptor::new(u);
550 visit_tydesc(tydesc, &mut v as &mut TyVisitor);
551 match v.unwrap().last_err {
558 pub fn repr_to_str<T>(t: &T) -> String {
559 let mut result = io::MemWriter::new();
560 write_repr(&mut result as &mut io::Writer, t).unwrap();
561 String::from_utf8(result.unwrap()).unwrap()
565 struct P {a: int, b: f64}
570 use std::io::stdio::println;
571 use std::char::is_alphabetic;
575 fn exact_test<T>(t: &T, e:&str) {
576 let mut m = io::MemWriter::new();
577 write_repr(&mut m as &mut io::Writer, t).unwrap();
578 let s = str::from_utf8(m.unwrap().as_slice()).unwrap().to_string();
579 assert_eq!(s.as_slice(), e);
582 exact_test(&10, "10");
583 exact_test(&true, "true");
584 exact_test(&false, "false");
585 exact_test(&1.234, "1.234f64");
586 exact_test(&("hello"), "\"hello\"");
588 exact_test(&(box(GC) 10), "box(GC) 10");
589 exact_test(&(box 10), "box 10");
590 exact_test(&(&10), "&10");
592 exact_test(&(&mut x), "&mut 10");
594 exact_test(&(0 as *()), "(0x0 as *())");
595 exact_test(&(0 as *mut ()), "(0x0 as *mut ())");
597 exact_test(&(1,), "(1,)");
598 exact_test(&(&["hi", "there"]),
599 "&[\"hi\", \"there\"]");
600 exact_test(&(P{a:10, b:1.234}),
601 "repr::P{a: 10, b: 1.234f64}");
602 exact_test(&(box(GC) P{a:10, b:1.234}),
603 "box(GC) repr::P{a: 10, b: 1.234f64}");
604 exact_test(&(box P{a:10, b:1.234}),
605 "box repr::P{a: 10, b: 1.234f64}");
607 exact_test(&(&[1, 2]), "&[1, 2]");
608 exact_test(&(&mut [1, 2]), "&mut [1, 2]");
610 exact_test(&'\'', "'\\''");
611 exact_test(&'"', "'\"'");
612 exact_test(&("'"), "\"'\"");
613 exact_test(&("\""), "\"\\\"\"");
615 exact_test(&println, "fn(&str)");
616 exact_test(&swap::<int>, "fn(&mut int, &mut int)");
617 exact_test(&is_alphabetic, "fn(char) -> bool");
619 struct Bar(int, int);
620 exact_test(&(Bar(2, 2)), "repr::test_repr::Bar(2, 2)");