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
*/
#[forbid(deprecated_mode)];
#[forbid(deprecated_pattern)];
use io::{Writer, WriterUtil};
use libc::c_void;
use to_str::ToStr;
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use cast::transmute;
use intrinsic::{TyDesc, TyVisitor, visit_tydesc};
use reflect::{MovePtr, MovePtrAdaptor, align};
use vec::UnboxedVecRepr;
use vec::raw::{VecRepr, SliceRepr};
pub use managed::raw::BoxRepr;
/// Helpers
trait EscapedCharWriter {
fn write_escaped_char(ch: char);
}
impl Writer : EscapedCharWriter {
fn write_escaped_char(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),
_ => {
// XXX: This is inefficient because it requires a malloc.
self.write_str(char::escape_unicode(ch))
}
}
}
}
/// Representations
trait Repr {
fn write_repr(writer: @Writer);
}
impl () : Repr {
fn write_repr(writer: @Writer) { writer.write_str("()"); }
}
impl bool : Repr {
fn write_repr(writer: @Writer) {
writer.write_str(if self { "true" } else { "false" })
}
}
impl int : Repr {
fn write_repr(writer: @Writer) { writer.write_int(self); }
}
impl i8 : Repr {
fn write_repr(writer: @Writer) { writer.write_int(self as int); }
}
impl i16 : Repr {
fn write_repr(writer: @Writer) { writer.write_int(self as int); }
}
impl i32 : Repr {
fn write_repr(writer: @Writer) { writer.write_int(self as int); }
}
impl i64 : Repr {
// XXX: This can lose precision.
fn write_repr(writer: @Writer) { writer.write_int(self as int); }
}
impl uint : Repr {
fn write_repr(writer: @Writer) { writer.write_uint(self); }
}
impl u8 : Repr {
fn write_repr(writer: @Writer) { writer.write_uint(self as uint); }
}
impl u16 : Repr {
fn write_repr(writer: @Writer) { writer.write_uint(self as uint); }
}
impl u32 : Repr {
fn write_repr(writer: @Writer) { writer.write_uint(self as uint); }
}
impl u64 : Repr {
// XXX: This can lose precision.
fn write_repr(writer: @Writer) { writer.write_uint(self as uint); }
}
impl float : Repr {
// XXX: This mallocs.
fn write_repr(writer: @Writer) { writer.write_str(self.to_str()); }
}
impl f32 : Repr {
// XXX: This mallocs.
fn write_repr(writer: @Writer) { writer.write_str(self.to_str()); }
}
impl f64 : Repr {
// XXX: This mallocs.
fn write_repr(writer: @Writer) { writer.write_str(self.to_str()); }
}
impl char : Repr {
fn write_repr(writer: @Writer) { writer.write_char(self); }
}
// New implementation using reflect::MovePtr
pub struct ReprVisitor {
mut ptr: *c_void,
writer: @Writer
}
pub fn ReprVisitor(ptr: *c_void, writer: @Writer) -> ReprVisitor {
ReprVisitor { ptr: ptr, writer: writer }
}
impl ReprVisitor : MovePtr {
#[inline(always)]
fn move_ptr(adjustment: fn(*c_void) -> *c_void) {
self.ptr = adjustment(self.ptr);
}
}
impl ReprVisitor {
// Various helpers for the TyVisitor impl
#[inline(always)]
fn get<T>(f: fn(&T)) -> bool {
unsafe {
f(transmute::<*c_void,&T>(copy self.ptr));
}
true
}
#[inline(always)]
fn visit_inner(inner: *TyDesc) -> bool {
self.visit_ptr_inner(self.ptr, inner)
}
#[inline(always)]
fn visit_ptr_inner(ptr: *c_void, inner: *TyDesc) -> bool {
let mut u = ReprVisitor(ptr, self.writer);
let v = reflect::MovePtrAdaptor(move u);
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visit_tydesc(inner, (move v) as @TyVisitor);
true
}
#[inline(always)]
fn write<T:Repr>() -> bool {
do self.get |v:&T| {
v.write_repr(self.writer);
}
}
fn write_escaped_slice(slice: &str) {
self.writer.write_char('"');
for str::chars_each(slice) |ch| {
self.writer.write_escaped_char(ch);
}
self.writer.write_char('"');
}
fn write_mut_qualifier(mtbl: uint) {
if mtbl == 0 {
self.writer.write_str("mut ");
} else if mtbl == 1 {
// skip, this is ast::m_imm
} else {
assert mtbl == 2;
self.writer.write_str("const ");
}
}
fn write_vec_range(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
}
fn write_unboxed_vec_repr(mtbl: uint, v: &UnboxedVecRepr,
inner: *TyDesc) -> bool {
self.write_vec_range(mtbl, ptr::to_unsafe_ptr(&v.data),
v.fill, inner)
}
}
impl ReprVisitor : TyVisitor {
fn visit_bot() -> bool {
self.writer.write_str("!");
true
}
fn visit_nil() -> bool { self.write::<()>() }
fn visit_bool() -> bool { self.write::<bool>() }
fn visit_int() -> bool { self.write::<int>() }
fn visit_i8() -> bool { self.write::<i8>() }
fn visit_i16() -> bool { self.write::<i16>() }
fn visit_i32() -> bool { self.write::<i32>() }
fn visit_i64() -> bool { self.write::<i64>() }
fn visit_uint() -> bool { self.write::<uint>() }
fn visit_u8() -> bool { self.write::<u8>() }
fn visit_u16() -> bool { self.write::<u16>() }
fn visit_u32() -> bool { self.write::<u32>() }
fn visit_u64() -> bool { self.write::<u64>() }
fn visit_float() -> bool { self.write::<float>() }
fn visit_f32() -> bool { self.write::<f32>() }
fn visit_f64() -> bool { self.write::<f64>() }
fn visit_char() -> bool { self.write::<uint>() }
// Type no longer exists, vestigial function.
fn visit_str() -> bool { fail; }
fn visit_estr_box() -> bool {
do self.get::<@str> |s| {
self.writer.write_char('@');
self.write_escaped_slice(*s);
}
}
fn visit_estr_uniq() -> bool {
do self.get::<~str> |s| {
self.writer.write_char('~');
self.write_escaped_slice(*s);
}
}
fn visit_estr_slice() -> bool {
do self.get::<&str> |s| {
self.write_escaped_slice(*s);
}
}
// Type no longer exists, vestigial function.
fn visit_estr_fixed(_n: uint, _sz: uint,
_align: uint) -> bool { fail; }
fn visit_box(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(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(_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(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(_mtbl: uint, _inner: *TyDesc) -> bool { fail; }
fn visit_unboxed_vec(mtbl: uint, inner: *TyDesc) -> bool {
do self.get::<vec::UnboxedVecRepr> |b| {
self.write_unboxed_vec_repr(mtbl, b, inner);
}
}
fn visit_evec_box(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(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(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(_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(_n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('{');
true
}
fn visit_rec_field(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(_n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('}');
true
}
fn visit_enter_class(_n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('{');
true
}
fn visit_class_field(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(_n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('}');
true
}
fn visit_enter_tup(_n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char('(');
true
}
fn visit_tup_field(i: uint, inner: *TyDesc) -> bool {
if i != 0 {
self.writer.write_str(", ");
}
self.visit_inner(inner);
true
}
fn visit_leave_tup(_n_fields: uint,
_sz: uint, _align: uint) -> bool {
self.writer.write_char(')');
true
}
fn visit_enter_enum(_n_variants: uint,
_sz: uint, _align: uint) -> bool {
true
}
fn visit_enter_enum_variant(_variant: uint,
_disr_val: int,
_n_fields: uint,
_name: &str) -> bool { true }
fn visit_enum_variant_field(_i: uint, inner: *TyDesc) -> bool {
self.visit_inner(inner)
}
fn visit_leave_enum_variant(_variant: uint,
_disr_val: int,
_n_fields: uint,
_name: &str) -> bool { true }
fn visit_leave_enum(_n_variants: uint,
_sz: uint, _align: uint) -> bool { true }
fn visit_enter_fn(_purity: uint, _proto: uint,
_n_inputs: uint, _retstyle: uint) -> bool { true }
fn visit_fn_input(_i: uint, _mode: uint, _inner: *TyDesc) -> bool { true }
fn visit_fn_output(_retstyle: uint, _inner: *TyDesc) -> bool { true }
fn visit_leave_fn(_purity: uint, _proto: uint,
_n_inputs: uint, _retstyle: uint) -> bool { true }
fn visit_trait() -> bool { true }
fn visit_var() -> bool { true }
fn visit_var_integral() -> bool { true }
fn visit_param(_i: uint) -> bool { true }
fn visit_self() -> bool { true }
fn visit_type() -> bool { true }
fn visit_opaque_box() -> 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(_inner: *TyDesc) -> bool { fail; }
fn visit_closure_ptr(_ck: uint) -> bool { true }
}
pub fn write_repr<T>(writer: @Writer, object: &T) {
let ptr = ptr::to_unsafe_ptr(object) as *c_void;
let tydesc = intrinsic::get_tydesc::<T>();
let mut u = ReprVisitor(ptr, writer);
let v = reflect::MovePtrAdaptor(move u);
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visit_tydesc(tydesc, (move v) as @TyVisitor)
}
#[test]
fn test_repr() {
fn exact_test<T>(t: &T, e:&str) {
let s : &str = io::with_str_writer(|w| repr::write_repr(w, t));
if s != e {
error!("expected '%s', got '%s'",
e, s);
}
assert s == e;
}
exact_test(&10, "10");
exact_test(&true, "true");
exact_test(&false, "false");
exact_test(&1.234, "1.2340");
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(&(~mut 10), "~mut 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(&({a:10, b:1.234}),
"{a: 10, b: 1.2340}");
exact_test(&(@{a:10, b:1.234}),
"@{a: 10, b: 1.2340}");
exact_test(&(~{a:10, b:1.234}),
"~{a: 10, b: 1.2340}");
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\")");
}