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 $ty {
75 fn write_repr(&self, writer: &mut io::Writer) -> io::IoResult<()> {
76 let s = self.to_str();
77 writer.write(s.as_bytes()).and_then(|()| {
78 writer.write(bytes!($suffix))
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>() }
261 fn visit_f128(&mut self) -> bool { fail!("not implemented") }
263 fn visit_char(&mut self) -> bool {
264 self.get::<char>(|this, &ch| {
265 try!(this, this.writer.write(['\'' as u8]));
266 if !this.write_escaped_char(ch, false) { return false }
267 try!(this, this.writer.write(['\'' as u8]));
272 fn visit_estr_slice(&mut self) -> bool {
273 self.get::<&str>(|this, s| this.write_escaped_slice(*s))
276 // Type no longer exists, vestigial function.
277 fn visit_estr_fixed(&mut self, _n: uint, _sz: uint,
278 _align: uint) -> bool { fail!(); }
280 fn visit_box(&mut self, mtbl: uint, inner: *TyDesc) -> bool {
281 try!(self, self.writer.write("box(GC) ".as_bytes()));
282 self.write_mut_qualifier(mtbl);
283 self.get::<&raw::Box<()>>(|this, b| {
284 let p = &b.data as *() as *u8;
285 this.visit_ptr_inner(p, inner)
289 fn visit_uniq(&mut self, _mtbl: uint, inner: *TyDesc) -> bool {
290 try!(self, self.writer.write("box ".as_bytes()));
291 self.get::<*u8>(|this, b| {
292 this.visit_ptr_inner(*b, inner)
296 fn visit_ptr(&mut self, mtbl: uint, _inner: *TyDesc) -> bool {
297 self.get::<*u8>(|this, p| {
298 try!(this, write!(this.writer, "({} as *", *p));
299 this.write_mut_qualifier(mtbl);
300 try!(this, this.writer.write("())".as_bytes()));
305 fn visit_rptr(&mut self, mtbl: uint, inner: *TyDesc) -> bool {
306 try!(self, self.writer.write(['&' as u8]));
307 self.write_mut_qualifier(mtbl);
308 self.get::<*u8>(|this, p| {
309 this.visit_ptr_inner(*p, inner)
313 fn visit_evec_slice(&mut self, mtbl: uint, inner: *TyDesc) -> bool {
314 self.get::<raw::Slice<()>>(|this, s| {
315 try!(this, this.writer.write(['&' as u8]));
316 this.write_mut_qualifier(mtbl);
318 if (*inner).size == 0 { 1 } else { (*inner).size }
320 this.write_vec_range(s.data, s.len * size, inner)
324 fn visit_evec_fixed(&mut self, n: uint, sz: uint, _align: uint,
325 _: uint, inner: *TyDesc) -> bool {
326 let assumed_size = if sz == 0 { n } else { sz };
327 self.get::<()>(|this, b| {
328 this.write_vec_range(b, assumed_size, inner)
332 fn visit_enter_rec(&mut self, _n_fields: uint,
333 _sz: uint, _align: uint) -> bool {
334 try!(self, self.writer.write(['{' as u8]));
338 fn visit_rec_field(&mut self, i: uint, name: &str,
339 mtbl: uint, inner: *TyDesc) -> bool {
341 try!(self, self.writer.write(", ".as_bytes()));
343 self.write_mut_qualifier(mtbl);
344 try!(self, self.writer.write(name.as_bytes()));
345 try!(self, self.writer.write(": ".as_bytes()));
346 self.visit_inner(inner);
350 fn visit_leave_rec(&mut self, _n_fields: uint,
351 _sz: uint, _align: uint) -> bool {
352 try!(self, self.writer.write(['}' as u8]));
356 fn visit_enter_class(&mut self, name: &str, named_fields: bool, n_fields: uint,
357 _sz: uint, _align: uint) -> bool {
358 try!(self, self.writer.write(name.as_bytes()));
361 try!(self, self.writer.write(['{' as u8]));
363 try!(self, self.writer.write(['(' as u8]));
369 fn visit_class_field(&mut self, i: uint, name: &str, named: bool,
370 _mtbl: uint, inner: *TyDesc) -> bool {
372 try!(self, self.writer.write(", ".as_bytes()));
375 try!(self, self.writer.write(name.as_bytes()));
376 try!(self, self.writer.write(": ".as_bytes()));
378 self.visit_inner(inner);
382 fn visit_leave_class(&mut self, _name: &str, named_fields: bool, n_fields: uint,
383 _sz: uint, _align: uint) -> bool {
386 try!(self, self.writer.write(['}' as u8]));
388 try!(self, self.writer.write([')' as u8]));
394 fn visit_enter_tup(&mut self, _n_fields: uint,
395 _sz: uint, _align: uint) -> bool {
396 try!(self, self.writer.write(['(' as u8]));
400 fn visit_tup_field(&mut self, i: uint, inner: *TyDesc) -> bool {
402 try!(self, self.writer.write(", ".as_bytes()));
404 self.visit_inner(inner);
408 fn visit_leave_tup(&mut self, _n_fields: uint,
409 _sz: uint, _align: uint) -> bool {
411 try!(self, self.writer.write([',' as u8]));
413 try!(self, self.writer.write([')' as u8]));
417 fn visit_enter_enum(&mut self,
419 get_disr: unsafe extern fn(ptr: *Opaque) -> Disr,
421 _align: uint) -> bool {
423 get_disr(mem::transmute(self.ptr))
425 self.var_stk.push(SearchingFor(disr));
429 fn visit_enter_enum_variant(&mut self, _variant: uint,
432 name: &str) -> bool {
433 let mut write = false;
434 match self.var_stk.pop().unwrap() {
435 SearchingFor(sought) => {
436 if disr_val == sought {
437 self.var_stk.push(Matched);
440 self.var_stk.push(SearchingFor(sought));
443 Matched | AlreadyFound => {
444 self.var_stk.push(AlreadyFound);
449 try!(self, self.writer.write(name.as_bytes()));
451 try!(self, self.writer.write(['(' as u8]));
457 fn visit_enum_variant_field(&mut self,
462 match *self.var_stk.get(self.var_stk.len() - 1) {
465 try!(self, self.writer.write(", ".as_bytes()));
467 if ! self.visit_inner(inner) {
476 fn visit_leave_enum_variant(&mut self, _variant: uint,
479 _name: &str) -> bool {
480 match *self.var_stk.get(self.var_stk.len() - 1) {
483 try!(self, self.writer.write([')' as u8]));
491 fn visit_leave_enum(&mut self,
493 _get_disr: unsafe extern fn(ptr: *Opaque) -> Disr,
497 match self.var_stk.pop().unwrap() {
498 SearchingFor(..) => fail!("enum value matched no variant"),
503 fn visit_enter_fn(&mut self, _purity: uint, _proto: uint,
504 _n_inputs: uint, _retstyle: uint) -> bool {
505 try!(self, self.writer.write("fn(".as_bytes()));
509 fn visit_fn_input(&mut self, i: uint, _mode: uint, inner: *TyDesc) -> bool {
511 try!(self, self.writer.write(", ".as_bytes()));
513 let name = unsafe { (*inner).name };
514 try!(self, self.writer.write(name.as_bytes()));
518 fn visit_fn_output(&mut self, _retstyle: uint, variadic: bool,
519 inner: *TyDesc) -> bool {
521 try!(self, self.writer.write(", ...".as_bytes()));
523 try!(self, self.writer.write(")".as_bytes()));
524 let name = unsafe { (*inner).name };
526 try!(self, self.writer.write(" -> ".as_bytes()));
527 try!(self, self.writer.write(name.as_bytes()));
532 fn visit_leave_fn(&mut self, _purity: uint, _proto: uint,
533 _n_inputs: uint, _retstyle: uint) -> bool { true }
536 fn visit_trait(&mut self, name: &str) -> bool {
537 try!(self, self.writer.write(name.as_bytes()));
541 fn visit_param(&mut self, _i: uint) -> bool { true }
542 fn visit_self(&mut self) -> bool { true }
545 pub fn write_repr<T>(writer: &mut io::Writer, object: &T) -> io::IoResult<()> {
547 let ptr = object as *T as *u8;
548 let tydesc = get_tydesc::<T>();
549 let u = ReprVisitor::new(ptr, writer);
550 let mut v = reflect::MovePtrAdaptor::new(u);
551 visit_tydesc(tydesc, &mut v as &mut TyVisitor);
552 match v.unwrap().last_err {
559 pub fn repr_to_str<T>(t: &T) -> String {
560 let mut result = io::MemWriter::new();
561 write_repr(&mut result as &mut io::Writer, t).unwrap();
562 String::from_utf8(result.unwrap()).unwrap()
566 struct P {a: int, b: f64}
571 use std::io::stdio::println;
572 use std::char::is_alphabetic;
576 fn exact_test<T>(t: &T, e:&str) {
577 let mut m = io::MemWriter::new();
578 write_repr(&mut m as &mut io::Writer, t).unwrap();
579 let s = str::from_utf8(m.unwrap().as_slice()).unwrap().to_string();
580 assert_eq!(s.as_slice(), e);
583 exact_test(&10, "10");
584 exact_test(&true, "true");
585 exact_test(&false, "false");
586 exact_test(&1.234, "1.234f64");
587 exact_test(&("hello"), "\"hello\"");
589 exact_test(&(box(GC) 10), "box(GC) 10");
590 exact_test(&(box 10), "box 10");
591 exact_test(&(&10), "&10");
593 exact_test(&(&mut x), "&mut 10");
595 exact_test(&(0 as *()), "(0x0 as *())");
596 exact_test(&(0 as *mut ()), "(0x0 as *mut ())");
598 exact_test(&(1,), "(1,)");
599 exact_test(&(&["hi", "there"]),
600 "&[\"hi\", \"there\"]");
601 exact_test(&(P{a:10, b:1.234}),
602 "repr::P{a: 10, b: 1.234f64}");
603 exact_test(&(box(GC) P{a:10, b:1.234}),
604 "box(GC) repr::P{a: 10, b: 1.234f64}");
605 exact_test(&(box P{a:10, b:1.234}),
606 "box repr::P{a: 10, b: 1.234f64}");
608 exact_test(&(&[1, 2]), "&[1, 2]");
609 exact_test(&(&mut [1, 2]), "&mut [1, 2]");
611 exact_test(&'\'', "'\\''");
612 exact_test(&'"', "'\"'");
613 exact_test(&("'"), "\"'\"");
614 exact_test(&("\""), "\"\\\"\"");
616 exact_test(&println, "fn(&str)");
617 exact_test(&swap::<int>, "fn(&mut int, &mut int)");
618 exact_test(&is_alphabetic, "fn(char) -> bool");
620 struct Bar(int, int);
621 exact_test(&(Bar(2, 2)), "repr::test_repr::Bar(2, 2)");