rust/src/libsyntax/ext/source_util.rs
2014-07-09 00:06:27 -07:00

205 lines
7.5 KiB
Rust

// Copyright 2012-2013 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.
use ast;
use codemap;
use codemap::{Pos, Span};
use codemap::{ExpnInfo, NameAndSpan};
use ext::base::*;
use ext::base;
use ext::build::AstBuilder;
use parse;
use parse::token;
use print::pprust;
use std::gc::Gc;
use std::io::File;
use std::rc::Rc;
use std::str;
// These macros all relate to the file system; they either return
// the column/row/filename of the expression, or they include
// a given file into the current one.
/// line!(): expands to the current line number
pub fn expand_line(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult> {
base::check_zero_tts(cx, sp, tts, "line!");
let topmost = topmost_expn_info(cx.backtrace().unwrap());
let loc = cx.codemap().lookup_char_pos(topmost.call_site.lo);
base::MacExpr::new(cx.expr_uint(topmost.call_site, loc.line))
}
/* col!(): expands to the current column number */
pub fn expand_col(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult> {
base::check_zero_tts(cx, sp, tts, "col!");
let topmost = topmost_expn_info(cx.backtrace().unwrap());
let loc = cx.codemap().lookup_char_pos(topmost.call_site.lo);
base::MacExpr::new(cx.expr_uint(topmost.call_site, loc.col.to_uint()))
}
/// file!(): expands to the current filename */
/// The filemap (`loc.file`) contains a bunch more information we could spit
/// out if we wanted.
pub fn expand_file(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult> {
base::check_zero_tts(cx, sp, tts, "file!");
let topmost = topmost_expn_info(cx.backtrace().unwrap());
let loc = cx.codemap().lookup_char_pos(topmost.call_site.lo);
let filename = token::intern_and_get_ident(loc.file.name.as_slice());
base::MacExpr::new(cx.expr_str(topmost.call_site, filename))
}
pub fn expand_stringify(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult> {
let s = pprust::tts_to_string(tts);
base::MacExpr::new(cx.expr_str(sp,
token::intern_and_get_ident(s.as_slice())))
}
pub fn expand_mod(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult> {
base::check_zero_tts(cx, sp, tts, "module_path!");
let string = cx.mod_path()
.iter()
.map(|x| token::get_ident(*x).get().to_string())
.collect::<Vec<String>>()
.connect("::");
base::MacExpr::new(cx.expr_str(
sp,
token::intern_and_get_ident(string.as_slice())))
}
/// include! : parse the given file as an expr
/// This is generally a bad idea because it's going to behave
/// unhygienically.
pub fn expand_include(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult> {
let file = match get_single_str_from_tts(cx, sp, tts, "include!") {
Some(f) => f,
None => return DummyResult::expr(sp),
};
// The file will be added to the code map by the parser
let mut p =
parse::new_sub_parser_from_file(cx.parse_sess(),
cx.cfg(),
&res_rel_file(cx,
sp,
&Path::new(file)),
true,
None,
sp);
base::MacExpr::new(p.parse_expr())
}
// include_str! : read the given file, insert it as a literal string expr
pub fn expand_include_str(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult> {
let file = match get_single_str_from_tts(cx, sp, tts, "include_str!") {
Some(f) => f,
None => return DummyResult::expr(sp)
};
let file = res_rel_file(cx, sp, &Path::new(file));
let bytes = match File::open(&file).read_to_end() {
Err(e) => {
cx.span_err(sp,
format!("couldn't read {}: {}",
file.display(),
e).as_slice());
return DummyResult::expr(sp);
}
Ok(bytes) => bytes,
};
match str::from_utf8(bytes.as_slice()) {
Some(src) => {
// Add this input file to the code map to make it available as
// dependency information
let filename = file.display().to_string();
let interned = token::intern_and_get_ident(src);
cx.codemap().new_filemap(filename, src.to_string());
base::MacExpr::new(cx.expr_str(sp, interned))
}
None => {
cx.span_err(sp,
format!("{} wasn't a utf-8 file",
file.display()).as_slice());
return DummyResult::expr(sp);
}
}
}
pub fn expand_include_bin(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
-> Box<base::MacResult> {
let file = match get_single_str_from_tts(cx, sp, tts, "include_bin!") {
Some(f) => f,
None => return DummyResult::expr(sp)
};
let file = res_rel_file(cx, sp, &Path::new(file));
match File::open(&file).read_to_end() {
Err(e) => {
cx.span_err(sp,
format!("couldn't read {}: {}",
file.display(),
e).as_slice());
return DummyResult::expr(sp);
}
Ok(bytes) => {
let bytes = bytes.iter().map(|x| *x).collect();
base::MacExpr::new(cx.expr_lit(sp, ast::LitBinary(Rc::new(bytes))))
}
}
}
// recur along an ExpnInfo chain to find the original expression
fn topmost_expn_info(expn_info: Gc<codemap::ExpnInfo>) -> Gc<codemap::ExpnInfo> {
match *expn_info {
ExpnInfo { call_site: ref call_site, .. } => {
match call_site.expn_info {
Some(next_expn_info) => {
match *next_expn_info {
ExpnInfo {
callee: NameAndSpan { name: ref name, .. },
..
} => {
// Don't recurse into file using "include!"
if "include" == name.as_slice() {
expn_info
} else {
topmost_expn_info(next_expn_info)
}
}
}
},
None => expn_info
}
}
}
}
// resolve a file-system path to an absolute file-system path (if it
// isn't already)
fn res_rel_file(cx: &mut ExtCtxt, sp: codemap::Span, arg: &Path) -> Path {
// NB: relative paths are resolved relative to the compilation unit
if !arg.is_absolute() {
let mut cu = Path::new(cx.codemap().span_to_filename(sp));
cu.pop();
cu.push(arg);
cu
} else {
arg.clone()
}
}