src/libsyntax_ext/source_util.rs

   1 use syntax_expand::panictry;
   2 use syntax_expand::base::{self, *};
   3 use syntax::ast;
   4 use syntax::parse::{self, token, DirectoryOwnership};
   5 use syntax::print::pprust;
   6 use syntax::ptr::P;
   7 use syntax::symbol::Symbol;
   8 use syntax::tokenstream::TokenStream;
   9 use syntax::early_buffered_lints::BufferedEarlyLintId;
  10
  11 use smallvec::SmallVec;
  12 use syntax_pos::{self, Pos, Span};
  13
  14 use rustc_data_structures::sync::Lrc;
  15
  16 // These macros all relate to the file system; they either return
  17 // the column/row/filename of the expression, or they include
  18 // a given file into the current one.
  19
  20 /// line!(): expands to the current line number
  21 pub fn expand_line(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  22                    -> Box<dyn base::MacResult+'static> {
  23     base::check_zero_tts(cx, sp, tts, "line!");
  24
  25     let topmost = cx.expansion_cause().unwrap_or(sp);
  26     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  27
  28     base::MacEager::expr(cx.expr_u32(topmost, loc.line as u32))
  29 }
  30
  31 /* column!(): expands to the current column number */
  32 pub fn expand_column(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  33                   -> Box<dyn base::MacResult+'static> {
  34     base::check_zero_tts(cx, sp, tts, "column!");
  35
  36     let topmost = cx.expansion_cause().unwrap_or(sp);
  37     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  38
  39     base::MacEager::expr(cx.expr_u32(topmost, loc.col.to_usize() as u32 + 1))
  40 }
  41
  42 /// file!(): expands to the current filename */
  43 /// The source_file (`loc.file`) contains a bunch more information we could spit
  44 /// out if we wanted.
  45 pub fn expand_file(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  46                    -> Box<dyn base::MacResult+'static> {
  47     base::check_zero_tts(cx, sp, tts, "file!");
  48
  49     let topmost = cx.expansion_cause().unwrap_or(sp);
  50     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  51     base::MacEager::expr(cx.expr_str(topmost, Symbol::intern(&loc.file.name.to_string())))
  52 }
  53
  54 pub fn expand_stringify(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  55                         -> Box<dyn base::MacResult+'static> {
  56     let s = pprust::tts_to_string(tts);
  57     base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&s)))
  58 }
  59
  60 pub fn expand_mod(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  61                   -> Box<dyn base::MacResult+'static> {
  62     base::check_zero_tts(cx, sp, tts, "module_path!");
  63     let mod_path = &cx.current_expansion.module.mod_path;
  64     let string = mod_path.iter().map(|x| x.to_string()).collect::<Vec<String>>().join("::");
  65
  66     base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&string)))
  67 }
  68
  69 /// include! : parse the given file as an expr
  70 /// This is generally a bad idea because it's going to behave
  71 /// unhygienically.
  72 pub fn expand_include<'cx>(cx: &'cx mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  73                            -> Box<dyn base::MacResult+'cx> {
  74     let file = match get_single_str_from_tts(cx, sp, tts, "include!") {
  75         Some(f) => f,
  76         None => return DummyResult::any(sp),
  77     };
  78     // The file will be added to the code map by the parser
  79     let file = match cx.resolve_path(file, sp) {
  80         Ok(f) => f,
  81         Err(mut err) => {
  82             err.emit();
  83             return DummyResult::any(sp);
  84         },
  85     };
  86     let directory_ownership = DirectoryOwnership::Owned { relative: None };
  87     let p = parse::new_sub_parser_from_file(cx.parse_sess(), &file, directory_ownership, None, sp);
  88
  89     struct ExpandResult<'a> {
  90         p: parse::parser::Parser<'a>,
  91     }
  92     impl<'a> base::MacResult for ExpandResult<'a> {
  93         fn make_expr(mut self: Box<ExpandResult<'a>>) -> Option<P<ast::Expr>> {
  94             let r = panictry!(self.p.parse_expr());
  95             if self.p.token != token::Eof {
  96                 self.p.sess.buffer_lint(
  97                     BufferedEarlyLintId::IncompleteInclude,
  98                     self.p.token.span,
  99                     ast::CRATE_NODE_ID,
 100                     "include macro expected single expression in source",
 101                 );
 102             }
 103             Some(r)
 104         }
 105
 106         fn make_items(mut self: Box<ExpandResult<'a>>) -> Option<SmallVec<[P<ast::Item>; 1]>> {
 107             let mut ret = SmallVec::new();
 108             while self.p.token != token::Eof {
 109                 match panictry!(self.p.parse_item()) {
 110                     Some(item) => ret.push(item),
 111                     None => self.p.sess.span_diagnostic.span_fatal(self.p.token.span,
 112                                                            &format!("expected item, found `{}`",
 113                                                                     self.p.this_token_to_string()))
 114                                                .raise()
 115                 }
 116             }
 117             Some(ret)
 118         }
 119     }
 120
 121     Box::new(ExpandResult { p })
 122 }
 123
 124 // include_str! : read the given file, insert it as a literal string expr
 125 pub fn expand_include_str(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
 126                           -> Box<dyn base::MacResult+'static> {
 127     let file = match get_single_str_from_tts(cx, sp, tts, "include_str!") {
 128         Some(f) => f,
 129         None => return DummyResult::any(sp)
 130     };
 131     let file = match cx.resolve_path(file, sp) {
 132         Ok(f) => f,
 133         Err(mut err) => {
 134             err.emit();
 135             return DummyResult::any(sp);
 136         },
 137     };
 138     match cx.source_map().load_binary_file(&file) {
 139         Ok(bytes) => match std::str::from_utf8(&bytes) {
 140             Ok(src) => {
 141                 let interned_src = Symbol::intern(&src);
 142                 base::MacEager::expr(cx.expr_str(sp, interned_src))
 143             }
 144             Err(_) => {
 145                 cx.span_err(sp, &format!("{} wasn't a utf-8 file", file.display()));
 146                 DummyResult::any(sp)
 147             }
 148         },
 149         Err(e) => {
 150             cx.span_err(sp, &format!("couldn't read {}: {}", file.display(), e));
 151             DummyResult::any(sp)
 152         }
 153     }
 154 }
 155
 156 pub fn expand_include_bytes(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
 157                             -> Box<dyn base::MacResult+'static> {
 158     let file = match get_single_str_from_tts(cx, sp, tts, "include_bytes!") {
 159         Some(f) => f,
 160         None => return DummyResult::any(sp)
 161     };
 162     let file = match cx.resolve_path(file, sp) {
 163         Ok(f) => f,
 164         Err(mut err) => {
 165             err.emit();
 166             return DummyResult::any(sp);
 167         },
 168     };
 169     match cx.source_map().load_binary_file(&file) {
 170         Ok(bytes) => {
 171             base::MacEager::expr(cx.expr_lit(sp, ast::LitKind::ByteStr(Lrc::new(bytes))))
 172         },
 173         Err(e) => {
 174             cx.span_err(sp, &format!("couldn't read {}: {}", file.display(), e));
 175             DummyResult::any(sp)
 176         }
 177     }
 178 }