rust/src/libcore/repr.rs

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// 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
*/
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use cast::transmute;
use char;
use intrinsic;
use intrinsic::{TyDesc, TyVisitor, visit_tydesc};
use io::{Writer, WriterUtil};
use libc::c_void;
use managed;
use ptr;
use reflect;
use reflect::{MovePtr, MovePtrAdaptor, align};
use str;
use sys;
use to_str::ToStr;
use vec::UnboxedVecRepr;
use vec::raw::{VecRepr, SliceRepr};
use vec;
#[cfg(test)] use io;
pub use managed::raw::BoxRepr;
/// Helpers
trait EscapedCharWriter {
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fn write_escaped_char(&self, ch: char);
}
impl EscapedCharWriter for @Writer {
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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),
_ => {
// FIXME #4423: This is inefficient because it requires a
// malloc.
self.write_str(char::escape_unicode(ch))
}
}
}
}
/// Representations
trait Repr {
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fn write_repr(&self, writer: @Writer);
}
impl Repr for () {
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fn write_repr(&self, writer: @Writer) { writer.write_str("()"); }
}
impl Repr for bool {
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fn write_repr(&self, writer: @Writer) {
writer.write_str(if *self { "true" } else { "false" })
}
}
impl Repr for int {
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fn write_repr(&self, writer: @Writer) { writer.write_int(*self); }
}
impl Repr for i8 {
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fn write_repr(&self, writer: @Writer) { writer.write_int(*self as int); }
}
impl Repr for i16 {
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fn write_repr(&self, writer: @Writer) { writer.write_int(*self as int); }
}
impl Repr for i32 {
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fn write_repr(&self, writer: @Writer) { writer.write_int(*self as int); }
}
impl Repr for i64 {
// FIXME #4424: This can lose precision.
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fn write_repr(&self, writer: @Writer) { writer.write_int(*self as int); }
}
impl Repr for uint {
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fn write_repr(&self, writer: @Writer) { writer.write_uint(*self); }
}
impl Repr for u8 {
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fn write_repr(&self, writer: @Writer) {
writer.write_uint(*self as uint);
}
}
impl Repr for u16 {
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fn write_repr(&self, writer: @Writer) {
writer.write_uint(*self as uint);
}
}
impl Repr for u32 {
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fn write_repr(&self, writer: @Writer) {
writer.write_uint(*self as uint);
}
}
impl Repr for u64 {
// FIXME #4424: This can lose precision.
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fn write_repr(&self, writer: @Writer) {
writer.write_uint(*self as uint);
}
}
impl Repr for float {
// FIXME #4423: This mallocs.
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fn write_repr(&self, writer: @Writer) { writer.write_str(self.to_str()); }
}
impl Repr for f32 {
// FIXME #4423 This mallocs.
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fn write_repr(&self, writer: @Writer) { writer.write_str(self.to_str()); }
}
impl Repr for f64 {
// FIXME #4423: This mallocs.
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fn write_repr(&self, writer: @Writer) { writer.write_str(self.to_str()); }
}
impl Repr for char {
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fn write_repr(&self, writer: @Writer) { writer.write_char(*self); }
}
// New implementation using reflect::MovePtr
enum VariantState {
Degenerate,
TagMatch,
TagMismatch,
}
pub struct ReprVisitor {
mut ptr: *c_void,
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mut ptr_stk: ~[*c_void],
mut var_stk: ~[VariantState],
writer: @Writer
}
pub fn ReprVisitor(ptr: *c_void, writer: @Writer) -> ReprVisitor {
ReprVisitor { ptr: ptr,
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ptr_stk: ~[],
var_stk: ~[],
writer: writer }
}
impl MovePtr for ReprVisitor {
#[inline(always)]
fn move_ptr(&self, adjustment: &fn(*c_void) -> *c_void) {
self.ptr = adjustment(self.ptr);
}
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fn push_ptr(&self) {
self.ptr_stk.push(self.ptr);
}
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fn pop_ptr(&self) {
self.ptr = self.ptr_stk.pop();
}
}
pub impl ReprVisitor {
// Various helpers for the TyVisitor impl
#[inline(always)]
fn get<T>(&self, f: &fn(&T)) -> bool {
unsafe {
f(transmute::<*c_void,&T>(copy self.ptr));
}
true
}
#[inline(always)]
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fn bump(&self, sz: uint) {
do self.move_ptr() |p| {
((p as uint) + sz) as *c_void
};
}
#[inline(always)]
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fn bump_past<T>(&self) {
self.bump(sys::size_of::<T>());
}
#[inline(always)]
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fn visit_inner(&self, inner: *TyDesc) -> bool {
self.visit_ptr_inner(self.ptr, inner)
}
#[inline(always)]
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fn visit_ptr_inner(&self, ptr: *c_void, inner: *TyDesc) -> bool {
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unsafe {
let mut u = ReprVisitor(ptr, self.writer);
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let v = reflect::MovePtrAdaptor(u);
visit_tydesc(inner, @v as @TyVisitor);
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true
}
}
#[inline(always)]
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fn write<T:Repr>(&self) -> bool {
do self.get |v:&T| {
v.write_repr(self.writer);
}
}
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fn write_escaped_slice(&self, slice: &str) {
self.writer.write_char('"');
for str::chars_each(slice) |ch| {
self.writer.write_escaped_char(ch);
}
self.writer.write_char('"');
}
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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 {
fail_unless!(mtbl == 2);
self.writer.write_str("const ");
}
}
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fn write_vec_range(&self, mtbl: uint, ptr: *u8, len: uint,
inner: *TyDesc) -> bool {
let mut p = ptr;
let end = ptr::offset(p, len);
let (sz, al) = unsafe { ((*inner).size, (*inner).align) };
self.writer.write_char('[');
let mut first = true;
while p as uint < end as uint {
if first {
first = false;
} else {
self.writer.write_str(", ");
}
self.write_mut_qualifier(mtbl);
self.visit_ptr_inner(p as *c_void, inner);
p = align(ptr::offset(p, sz) as uint, al) as *u8;
}
self.writer.write_char(']');
true
}
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fn write_unboxed_vec_repr(&self, mtbl: uint, v: &UnboxedVecRepr,
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('\'');
}
}
// Type no longer exists, vestigial function.
fn visit_str(&self) -> bool { fail!(); }
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::<&managed::raw::BoxRepr> |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('~');
self.write_mut_qualifier(mtbl);
do self.get::<&managed::raw::BoxRepr> |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::<vec::UnboxedVecRepr> |b| {
self.write_unboxed_vec_repr(mtbl, b, inner);
}
}
fn visit_evec_box(&self, mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<&VecRepr> |b| {
self.writer.write_char('@');
self.write_unboxed_vec_repr(mtbl, &b.unboxed, inner);
}
}
fn visit_evec_uniq(&self, mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<&VecRepr> |b| {
self.writer.write_char('~');
self.write_unboxed_vec_repr(mtbl, &b.unboxed, inner);
}
}
fn visit_evec_slice(&self, mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<SliceRepr> |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::<u8> |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 {
self.writer.write_char(')');
true
}
fn visit_enter_enum(&self, n_variants: uint,
_sz: uint, _align: uint) -> bool {
if n_variants == 1 {
self.var_stk.push(Degenerate)
} else {
self.var_stk.push(TagMatch)
}
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() {
Degenerate => {
write = true;
self.var_stk.push(Degenerate);
}
TagMatch | TagMismatch => {
do self.get::<int>() |t| {
if disr_val == *t {
write = true;
self.var_stk.push(TagMatch);
} else {
self.var_stk.push(TagMismatch);
}
};
self.bump_past::<int>();
}
}
if write {
self.writer.write_str(name);
if n_fields > 0 {
self.writer.write_char('(');
}
}
true
}
fn visit_enum_variant_field(&self, i: uint, inner: *TyDesc) -> bool {
match self.var_stk[vec::uniq_len(&const self.var_stk) - 1] {
Degenerate | TagMatch => {
if i != 0 {
self.writer.write_str(", ");
}
if ! self.visit_inner(inner) {
return false;
}
}
TagMismatch => ()
}
true
}
fn visit_leave_enum_variant(&self, _variant: uint,
_disr_val: int,
n_fields: uint,
_name: &str) -> bool {
match self.var_stk[vec::uniq_len(&const self.var_stk) - 1] {
Degenerate | TagMatch => {
if n_fields > 0 {
self.writer.write_char(')');
}
}
TagMismatch => ()
}
true
}
fn visit_leave_enum(&self, _n_variants: uint,
_sz: uint, _align: uint) -> bool {
self.var_stk.pop();
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::<&managed::raw::BoxRepr> |b| {
let p = ptr::to_unsafe_ptr(&b.data) as *c_void;
self.visit_ptr_inner(p, b.header.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) {
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unsafe {
let ptr = ptr::to_unsafe_ptr(object) as *c_void;
let tydesc = intrinsic::get_tydesc::<T>();
let mut u = ReprVisitor(ptr, writer);
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let v = reflect::MovePtrAdaptor(u);
visit_tydesc(tydesc, @v as @TyVisitor)
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}
}
#[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);
}
fail_unless!(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\"");
// FIXME #4210: the mut fields are a bit off here.
exact_test(&(@10), "@10");
exact_test(&(@mut 10), "@10");
exact_test(&(~10), "~10");
exact_test(&(&10), "&10");
let mut x = 10;
exact_test(&(&mut x), "&mut 10");
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\")");
}