rust/src/libstd/repr.rs
2013-08-12 17:37:46 -04:00

630 lines
18 KiB
Rust

// Copyright 2012 The Rust Project Developers. See the COPYRIGHT
// file at the top-level directory of this distribution and at
// http://rust-lang.org/COPYRIGHT.
//
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
// option. This file may not be copied, modified, or distributed
// except according to those terms.
/*!
More runtime type reflection
*/
#[allow(missing_doc)];
use cast::transmute;
use char;
use container::Container;
use io::{Writer, WriterUtil};
use iterator::Iterator;
use libc::c_void;
use option::{Some, None};
use ptr;
use reflect;
use reflect::{MovePtr, align};
use str::StrSlice;
use to_str::ToStr;
use vec::OwnedVector;
use unstable::intrinsics::{Opaque, TyDesc, TyVisitor, get_tydesc, visit_tydesc};
use unstable::raw;
#[cfg(test)] use io;
/// Helpers
trait EscapedCharWriter {
fn write_escaped_char(&self, ch: char);
}
impl EscapedCharWriter for @Writer {
fn write_escaped_char(&self, ch: char) {
match ch {
'\t' => self.write_str("\\t"),
'\r' => self.write_str("\\r"),
'\n' => self.write_str("\\n"),
'\\' => self.write_str("\\\\"),
'\'' => self.write_str("\\'"),
'"' => self.write_str("\\\""),
'\x20'..'\x7e' => self.write_char(ch),
_ => {
do char::escape_unicode(ch) |c| {
self.write_char(c);
}
}
}
}
}
/// Representations
trait Repr {
fn write_repr(&self, writer: @Writer);
}
impl Repr for () {
fn write_repr(&self, writer: @Writer) { writer.write_str("()"); }
}
impl Repr for bool {
fn write_repr(&self, writer: @Writer) {
writer.write_str(if *self { "true" } else { "false" })
}
}
macro_rules! int_repr(($ty:ident) => (impl Repr for $ty {
fn write_repr(&self, writer: @Writer) {
do ::$ty::to_str_bytes(*self, 10u) |bits| {
writer.write(bits);
}
}
}))
int_repr!(int)
int_repr!(i8)
int_repr!(i16)
int_repr!(i32)
int_repr!(i64)
int_repr!(uint)
int_repr!(u8)
int_repr!(u16)
int_repr!(u32)
int_repr!(u64)
macro_rules! num_repr(($ty:ident) => (impl Repr for $ty {
fn write_repr(&self, writer: @Writer) {
let s = self.to_str();
writer.write(s.as_bytes());
}
}))
num_repr!(float)
num_repr!(f32)
num_repr!(f64)
// New implementation using reflect::MovePtr
enum VariantState {
SearchingFor(int),
Matched,
AlreadyFound
}
pub struct ReprVisitor {
ptr: @mut *c_void,
ptr_stk: @mut ~[*c_void],
var_stk: @mut ~[VariantState],
writer: @Writer
}
pub fn ReprVisitor(ptr: *c_void, writer: @Writer) -> ReprVisitor {
ReprVisitor {
ptr: @mut ptr,
ptr_stk: @mut ~[],
var_stk: @mut ~[],
writer: writer,
}
}
impl MovePtr for ReprVisitor {
#[inline]
fn move_ptr(&self, adjustment: &fn(*c_void) -> *c_void) {
*self.ptr = adjustment(*self.ptr);
}
fn push_ptr(&self) {
self.ptr_stk.push(*self.ptr);
}
fn pop_ptr(&self) {
*self.ptr = self.ptr_stk.pop();
}
}
impl ReprVisitor {
// Various helpers for the TyVisitor impl
#[inline]
pub fn get<T>(&self, f: &fn(&T)) -> bool {
unsafe {
f(transmute::<*c_void,&T>(*self.ptr));
}
true
}
#[inline]
pub fn visit_inner(&self, inner: *TyDesc) -> bool {
self.visit_ptr_inner(*self.ptr, inner)
}
#[inline]
pub fn visit_ptr_inner(&self, ptr: *c_void, inner: *TyDesc) -> bool {
unsafe {
let u = ReprVisitor(ptr, self.writer);
let v = reflect::MovePtrAdaptor(u);
visit_tydesc(inner, &v as &TyVisitor);
true
}
}
#[inline]
pub fn write<T:Repr>(&self) -> bool {
do self.get |v:&T| {
v.write_repr(self.writer);
}
}
pub fn write_escaped_slice(&self, slice: &str) {
self.writer.write_char('"');
for ch in slice.iter() {
self.writer.write_escaped_char(ch);
}
self.writer.write_char('"');
}
pub fn write_mut_qualifier(&self, mtbl: uint) {
if mtbl == 0 {
self.writer.write_str("mut ");
} else if mtbl == 1 {
// skip, this is ast::m_imm
} else {
assert_eq!(mtbl, 2);
self.writer.write_str("const ");
}
}
pub fn write_vec_range(&self,
_mtbl: uint,
ptr: *(),
len: uint,
inner: *TyDesc)
-> bool {
let mut p = ptr as *u8;
let (sz, al) = unsafe { ((*inner).size, (*inner).align) };
self.writer.write_char('[');
let mut first = true;
let mut left = len;
// unit structs have 0 size, and don't loop forever.
let dec = if sz == 0 {1} else {sz};
while left > 0 {
if first {
first = false;
} else {
self.writer.write_str(", ");
}
self.visit_ptr_inner(p as *c_void, inner);
p = align(ptr::offset(p, sz as int) as uint, al) as *u8;
left -= dec;
}
self.writer.write_char(']');
true
}
pub fn write_unboxed_vec_repr(&self,
mtbl: uint,
v: &raw::Vec<()>,
inner: *TyDesc)
-> bool {
self.write_vec_range(mtbl, ptr::to_unsafe_ptr(&v.data),
v.fill, inner)
}
}
impl TyVisitor for ReprVisitor {
fn visit_bot(&self) -> bool {
self.writer.write_str("!");
true
}
fn visit_nil(&self) -> bool { self.write::<()>() }
fn visit_bool(&self) -> bool { self.write::<bool>() }
fn visit_int(&self) -> bool { self.write::<int>() }
fn visit_i8(&self) -> bool { self.write::<i8>() }
fn visit_i16(&self) -> bool { self.write::<i16>() }
fn visit_i32(&self) -> bool { self.write::<i32>() }
fn visit_i64(&self) -> bool { self.write::<i64>() }
fn visit_uint(&self) -> bool { self.write::<uint>() }
fn visit_u8(&self) -> bool { self.write::<u8>() }
fn visit_u16(&self) -> bool { self.write::<u16>() }
fn visit_u32(&self) -> bool { self.write::<u32>() }
fn visit_u64(&self) -> bool { self.write::<u64>() }
fn visit_float(&self) -> bool { self.write::<float>() }
fn visit_f32(&self) -> bool { self.write::<f32>() }
fn visit_f64(&self) -> bool { self.write::<f64>() }
fn visit_char(&self) -> bool {
do self.get::<char> |&ch| {
self.writer.write_char('\'');
self.writer.write_escaped_char(ch);
self.writer.write_char('\'');
}
}
fn visit_estr_box(&self) -> bool {
do self.get::<@str> |s| {
self.writer.write_char('@');
self.write_escaped_slice(*s);
}
}
fn visit_estr_uniq(&self) -> bool {
do self.get::<~str> |s| {
self.writer.write_char('~');
self.write_escaped_slice(*s);
}
}
fn visit_estr_slice(&self) -> bool {
do self.get::<&str> |s| {
self.write_escaped_slice(*s);
}
}
// Type no longer exists, vestigial function.
fn visit_estr_fixed(&self, _n: uint, _sz: uint,
_align: uint) -> bool { fail!(); }
fn visit_box(&self, mtbl: uint, inner: *TyDesc) -> bool {
self.writer.write_char('@');
self.write_mut_qualifier(mtbl);
do self.get::<&raw::Box<()>> |b| {
let p = ptr::to_unsafe_ptr(&b.data) as *c_void;
self.visit_ptr_inner(p, inner);
}
}
fn visit_uniq(&self, _mtbl: uint, inner: *TyDesc) -> bool {
self.writer.write_char('~');
do self.get::<*c_void> |b| {
self.visit_ptr_inner(*b, inner);
}
}
fn visit_uniq_managed(&self, _mtbl: uint, inner: *TyDesc) -> bool {
self.writer.write_char('~');
do self.get::<&raw::Box<()>> |b| {
let p = ptr::to_unsafe_ptr(&b.data) as *c_void;
self.visit_ptr_inner(p, inner);
}
}
fn visit_ptr(&self, _mtbl: uint, _inner: *TyDesc) -> bool {
do self.get::<*c_void> |p| {
self.writer.write_str(fmt!("(0x%x as *())",
*p as uint));
}
}
fn visit_rptr(&self, mtbl: uint, inner: *TyDesc) -> bool {
self.writer.write_char('&');
self.write_mut_qualifier(mtbl);
do self.get::<*c_void> |p| {
self.visit_ptr_inner(*p, inner);
}
}
// Type no longer exists, vestigial function.
fn visit_vec(&self, _mtbl: uint, _inner: *TyDesc) -> bool { fail!(); }
fn visit_unboxed_vec(&self, mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<raw::Vec<()>> |b| {
self.write_unboxed_vec_repr(mtbl, b, inner);
}
}
fn visit_evec_box(&self, mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<&raw::Box<raw::Vec<()>>> |b| {
self.writer.write_char('@');
self.write_mut_qualifier(mtbl);
self.write_unboxed_vec_repr(mtbl, &b.data, inner);
}
}
fn visit_evec_uniq(&self, mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<&raw::Vec<()>> |b| {
self.writer.write_char('~');
self.write_unboxed_vec_repr(mtbl, *b, inner);
}
}
fn visit_evec_uniq_managed(&self, mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<&raw::Box<raw::Vec<()>>> |b| {
self.writer.write_char('~');
self.write_unboxed_vec_repr(mtbl, &b.data, inner);
}
}
fn visit_evec_slice(&self, mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<raw::Slice<()>> |s| {
self.writer.write_char('&');
self.write_vec_range(mtbl, s.data, s.len, inner);
}
}
fn visit_evec_fixed(&self, _n: uint, sz: uint, _align: uint,
mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<()> |b| {
self.write_vec_range(mtbl, ptr::to_unsafe_ptr(b), sz, inner);
}
}
fn visit_enter_rec(&self, _n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('{');
true
}
fn visit_rec_field(&self, i: uint, name: &str,
mtbl: uint, inner: *TyDesc) -> bool {
if i != 0 {
self.writer.write_str(", ");
}
self.write_mut_qualifier(mtbl);
self.writer.write_str(name);
self.writer.write_str(": ");
self.visit_inner(inner);
true
}
fn visit_leave_rec(&self, _n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('}');
true
}
fn visit_enter_class(&self, _n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('{');
true
}
fn visit_class_field(&self, i: uint, name: &str,
mtbl: uint, inner: *TyDesc) -> bool {
if i != 0 {
self.writer.write_str(", ");
}
self.write_mut_qualifier(mtbl);
self.writer.write_str(name);
self.writer.write_str(": ");
self.visit_inner(inner);
true
}
fn visit_leave_class(&self, _n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('}');
true
}
fn visit_enter_tup(&self, _n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('(');
true
}
fn visit_tup_field(&self, i: uint, inner: *TyDesc) -> bool {
if i != 0 {
self.writer.write_str(", ");
}
self.visit_inner(inner);
true
}
fn visit_leave_tup(&self, _n_fields: uint,
_sz: uint, _align: uint) -> bool {
if _n_fields == 1 {
self.writer.write_char(',');
}
self.writer.write_char(')');
true
}
fn visit_enter_enum(&self,
_n_variants: uint,
get_disr: extern unsafe fn(ptr: *Opaque) -> int,
_sz: uint,
_align: uint) -> bool {
let var_stk: &mut ~[VariantState] = self.var_stk;
let disr = unsafe {
get_disr(transmute(*self.ptr))
};
var_stk.push(SearchingFor(disr));
true
}
fn visit_enter_enum_variant(&self, _variant: uint,
disr_val: int,
n_fields: uint,
name: &str) -> bool {
let mut write = false;
match self.var_stk.pop() {
SearchingFor(sought) => {
if disr_val == sought {
self.var_stk.push(Matched);
write = true;
} else {
self.var_stk.push(SearchingFor(sought));
}
}
Matched | AlreadyFound => {
self.var_stk.push(AlreadyFound);
}
}
if write {
self.writer.write_str(name);
if n_fields > 0 {
self.writer.write_char('(');
}
}
true
}
fn visit_enum_variant_field(&self,
i: uint,
_offset: uint,
inner: *TyDesc)
-> bool {
match self.var_stk[self.var_stk.len() - 1] {
Matched => {
if i != 0 {
self.writer.write_str(", ");
}
if ! self.visit_inner(inner) {
return false;
}
}
_ => ()
}
true
}
fn visit_leave_enum_variant(&self, _variant: uint,
_disr_val: int,
n_fields: uint,
_name: &str) -> bool {
match self.var_stk[self.var_stk.len() - 1] {
Matched => {
if n_fields > 0 {
self.writer.write_char(')');
}
}
_ => ()
}
true
}
fn visit_leave_enum(&self,
_n_variants: uint,
_get_disr: extern unsafe fn(ptr: *Opaque) -> int,
_sz: uint,
_align: uint)
-> bool {
let var_stk: &mut ~[VariantState] = self.var_stk;
match var_stk.pop() {
SearchingFor(*) => fail!("enum value matched no variant"),
_ => true
}
}
fn visit_enter_fn(&self, _purity: uint, _proto: uint,
_n_inputs: uint, _retstyle: uint) -> bool { true }
fn visit_fn_input(&self, _i: uint, _mode: uint, _inner: *TyDesc) -> bool {
true
}
fn visit_fn_output(&self, _retstyle: uint, _inner: *TyDesc) -> bool {
true
}
fn visit_leave_fn(&self, _purity: uint, _proto: uint,
_n_inputs: uint, _retstyle: uint) -> bool { true }
fn visit_trait(&self) -> bool { true }
fn visit_var(&self) -> bool { true }
fn visit_var_integral(&self) -> bool { true }
fn visit_param(&self, _i: uint) -> bool { true }
fn visit_self(&self) -> bool { true }
fn visit_type(&self) -> bool { true }
fn visit_opaque_box(&self) -> bool {
self.writer.write_char('@');
do self.get::<&raw::Box<()>> |b| {
let p = ptr::to_unsafe_ptr(&b.data) as *c_void;
self.visit_ptr_inner(p, b.type_desc);
}
}
// Type no longer exists, vestigial function.
fn visit_constr(&self, _inner: *TyDesc) -> bool { fail!(); }
fn visit_closure_ptr(&self, _ck: uint) -> bool { true }
}
pub fn write_repr<T>(writer: @Writer, object: &T) {
unsafe {
let ptr = ptr::to_unsafe_ptr(object) as *c_void;
let tydesc = get_tydesc::<T>();
let u = ReprVisitor(ptr, writer);
let v = reflect::MovePtrAdaptor(u);
visit_tydesc(tydesc, &v as &TyVisitor)
}
}
#[cfg(test)]
struct P {a: int, b: float}
#[test]
fn test_repr() {
fn exact_test<T>(t: &T, e:&str) {
let s : &str = io::with_str_writer(|w| write_repr(w, t));
if s != e {
error!("expected '%s', got '%s'",
e, s);
}
assert_eq!(s, e);
}
exact_test(&10, "10");
exact_test(&true, "true");
exact_test(&false, "false");
exact_test(&1.234, "1.234");
exact_test(&(&"hello"), "\"hello\"");
exact_test(&(@"hello"), "@\"hello\"");
exact_test(&(~"he\u10f3llo"), "~\"he\\u10f3llo\"");
exact_test(&(@10), "@10");
exact_test(&(@mut 10), "@10"); // FIXME: #4210: incorrect
exact_test(&((@mut 10, 2)), "(@mut 10, 2)");
exact_test(&(~10), "~10");
exact_test(&(&10), "&10");
let mut x = 10;
exact_test(&(&mut x), "&mut 10");
exact_test(&(@mut [1, 2]), "@mut [1, 2]");
exact_test(&(1,), "(1,)");
exact_test(&(@[1,2,3,4,5,6,7,8]),
"@[1, 2, 3, 4, 5, 6, 7, 8]");
exact_test(&(@[1u8,2u8,3u8,4u8]),
"@[1, 2, 3, 4]");
exact_test(&(@["hi", "there"]),
"@[\"hi\", \"there\"]");
exact_test(&(~["hi", "there"]),
"~[\"hi\", \"there\"]");
exact_test(&(&["hi", "there"]),
"&[\"hi\", \"there\"]");
exact_test(&(P{a:10, b:1.234}),
"{a: 10, b: 1.234}");
exact_test(&(@P{a:10, b:1.234}),
"@{a: 10, b: 1.234}");
exact_test(&(~P{a:10, b:1.234}),
"~{a: 10, b: 1.234}");
exact_test(&(10_u8, ~"hello"),
"(10, ~\"hello\")");
exact_test(&(10_u16, ~"hello"),
"(10, ~\"hello\")");
exact_test(&(10_u32, ~"hello"),
"(10, ~\"hello\")");
exact_test(&(10_u64, ~"hello"),
"(10, ~\"hello\")");
struct Foo;
exact_test(&(~[Foo, Foo, Foo]), "~[{}, {}, {}]");
}