1 // Copyright 2012-2013 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.
4 //
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.
10
11 use ast;
12 use codemap;
13 use codemap::{Pos, Span};
14 use codemap::{ExpnInfo, NameAndSpan};
15 use ext::base::*;
16 use ext::base;
17 use ext::build::AstBuilder;
18 use parse;
19 use parse::token;
20 use print::pprust;
21
22 use std::io::File;
23 use std::rc::Rc;
24 use std::str;
25
26 // These macros all relate to the file system; they either return
27 // the column/row/filename of the expression, or they include
28 // a given file into the current one.
29
30 /* line!(): expands to the current line number */
31 pub fn expand_line(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
32 -> Box<base::MacResult> {
33 base::check_zero_tts(cx, sp, tts, "line!");
34
35 let topmost = topmost_expn_info(cx.backtrace().unwrap());
36 let loc = cx.codemap().lookup_char_pos(topmost.call_site.lo);
37
38 base::MacExpr::new(cx.expr_uint(topmost.call_site, loc.line))
39 }
40
41 /* col!(): expands to the current column number */
42 pub fn expand_col(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
43 -> Box<base::MacResult> {
44 base::check_zero_tts(cx, sp, tts, "col!");
45
46 let topmost = topmost_expn_info(cx.backtrace().unwrap());
47 let loc = cx.codemap().lookup_char_pos(topmost.call_site.lo);
48 base::MacExpr::new(cx.expr_uint(topmost.call_site, loc.col.to_uint()))
49 }
50
51 /* file!(): expands to the current filename */
52 /* The filemap (`loc.file`) contains a bunch more information we could spit
53 * out if we wanted. */
54 pub fn expand_file(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
55 -> Box<base::MacResult> {
56 base::check_zero_tts(cx, sp, tts, "file!");
57
58 let topmost = topmost_expn_info(cx.backtrace().unwrap());
59 let loc = cx.codemap().lookup_char_pos(topmost.call_site.lo);
60 let filename = token::intern_and_get_ident(loc.file.name.as_slice());
61 base::MacExpr::new(cx.expr_str(topmost.call_site, filename))
62 }
63
64 pub fn expand_stringify(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
65 -> Box<base::MacResult> {
66 let s = pprust::tts_to_str(tts);
67 base::MacExpr::new(cx.expr_str(sp,
68 token::intern_and_get_ident(s.as_slice())))
69 }
70
71 pub fn expand_mod(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
72 -> Box<base::MacResult> {
73 base::check_zero_tts(cx, sp, tts, "module_path!");
74 let string = cx.mod_path()
75 .iter()
76 .map(|x| token::get_ident(*x).get().to_strbuf())
77 .collect::<Vec<StrBuf>>()
78 .connect("::");
79 base::MacExpr::new(cx.expr_str(sp, token::intern_and_get_ident(string)))
80 }
81
82 // include! : parse the given file as an expr
83 // This is generally a bad idea because it's going to behave
84 // unhygienically.
85 pub fn expand_include(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
86 -> Box<base::MacResult> {
87 let file = match get_single_str_from_tts(cx, sp, tts, "include!") {
88 Some(f) => f,
89 None => return DummyResult::expr(sp),
90 };
91 // The file will be added to the code map by the parser
92 let mut p =
93 parse::new_sub_parser_from_file(cx.parse_sess(),
94 cx.cfg(),
95 &res_rel_file(cx,
96 sp,
97 &Path::new(file)),
98 sp);
99 base::MacExpr::new(p.parse_expr())
100 }
101
102 // include_str! : read the given file, insert it as a literal string expr
103 pub fn expand_include_str(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
104 -> Box<base::MacResult> {
105 let file = match get_single_str_from_tts(cx, sp, tts, "include_str!") {
106 Some(f) => f,
107 None => return DummyResult::expr(sp)
108 };
109 let file = res_rel_file(cx, sp, &Path::new(file));
110 let bytes = match File::open(&file).read_to_end() {
111 Err(e) => {
112 cx.span_err(sp, format!("couldn't read {}: {}", file.display(), e));
113 return DummyResult::expr(sp);
114 }
115 Ok(bytes) => bytes,
116 };
117 match str::from_utf8(bytes.as_slice()) {
118 Some(src) => {
119 // Add this input file to the code map to make it available as
120 // dependency information
121 let filename = file.display().to_str().to_strbuf();
122 let interned = token::intern_and_get_ident(src);
123 cx.codemap().new_filemap(filename, src.to_strbuf());
124
125 base::MacExpr::new(cx.expr_str(sp, interned))
126 }
127 None => {
128 cx.span_err(sp, format!("{} wasn't a utf-8 file", file.display()));
129 return DummyResult::expr(sp);
130 }
131 }
132 }
133
134 pub fn expand_include_bin(cx: &mut ExtCtxt, sp: Span, tts: &[ast::TokenTree])
135 -> Box<base::MacResult> {
136 let file = match get_single_str_from_tts(cx, sp, tts, "include_bin!") {
137 Some(f) => f,
138 None => return DummyResult::expr(sp)
139 };
140 let file = res_rel_file(cx, sp, &Path::new(file));
141 match File::open(&file).read_to_end() {
142 Err(e) => {
143 cx.span_err(sp, format!("couldn't read {}: {}", file.display(), e));
144 return DummyResult::expr(sp);
145 }
146 Ok(bytes) => {
147 let bytes = bytes.iter().map(|x| *x).collect();
148 base::MacExpr::new(cx.expr_lit(sp, ast::LitBinary(Rc::new(bytes))))
149 }
150 }
151 }
152
153 // recur along an ExpnInfo chain to find the original expression
154 fn topmost_expn_info(expn_info: @codemap::ExpnInfo) -> @codemap::ExpnInfo {
155 match *expn_info {
156 ExpnInfo { call_site: ref call_site, .. } => {
157 match call_site.expn_info {
158 Some(next_expn_info) => {
159 match *next_expn_info {
160 ExpnInfo {
161 callee: NameAndSpan { name: ref name, .. },
162 ..
163 } => {
164 // Don't recurse into file using "include!"
165 if "include" == name.as_slice() {
166 expn_info
167 } else {
168 topmost_expn_info(next_expn_info)
169 }
170 }
171 }
172 },
173 None => expn_info
174 }
175 }
176 }
177 }
178
179 // resolve a file-system path to an absolute file-system path (if it
180 // isn't already)
181 fn res_rel_file(cx: &mut ExtCtxt, sp: codemap::Span, arg: &Path) -> Path {
182 // NB: relative paths are resolved relative to the compilation unit
183 if !arg.is_absolute() {
184 let mut cu = Path::new(cx.codemap().span_to_filename(sp));
185 cu.pop();
186 cu.push(arg);
187 cu
188 } else {
189 arg.clone()
190 }
191 }