src/libsyntax_ext/source_util.rs

   1 use rustc_parse::{self, DirectoryOwnership, new_sub_parser_from_file, parser::Parser};
   2 use syntax::ast;
   3 use syntax::print::pprust;
   4 use syntax::ptr::P;
   5 use syntax::symbol::Symbol;
   6 use syntax::token;
   7 use syntax::tokenstream::TokenStream;
   8 use syntax::early_buffered_lints::BufferedEarlyLintId;
   9 use syntax_expand::panictry;
  10 use syntax_expand::base::{self, *};
  11
  12 use smallvec::SmallVec;
  13 use syntax_pos::{self, Pos, Span};
  14
  15 use rustc_data_structures::sync::Lrc;
  16
  17 // These macros all relate to the file system; they either return
  18 // the column/row/filename of the expression, or they include
  19 // a given file into the current one.
  20
  21 /// line!(): expands to the current line number
  22 pub fn expand_line(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  23                    -> Box<dyn base::MacResult+'static> {
  24     base::check_zero_tts(cx, sp, tts, "line!");
  25
  26     let topmost = cx.expansion_cause().unwrap_or(sp);
  27     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  28
  29     base::MacEager::expr(cx.expr_u32(topmost, loc.line as u32))
  30 }
  31
  32 /* column!(): expands to the current column number */
  33 pub fn expand_column(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  34                   -> Box<dyn base::MacResult+'static> {
  35     base::check_zero_tts(cx, sp, tts, "column!");
  36
  37     let topmost = cx.expansion_cause().unwrap_or(sp);
  38     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  39
  40     base::MacEager::expr(cx.expr_u32(topmost, loc.col.to_usize() as u32 + 1))
  41 }
  42
  43 /// file!(): expands to the current filename */
  44 /// The source_file (`loc.file`) contains a bunch more information we could spit
  45 /// out if we wanted.
  46 pub fn expand_file(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  47                    -> Box<dyn base::MacResult+'static> {
  48     base::check_zero_tts(cx, sp, tts, "file!");
  49
  50     let topmost = cx.expansion_cause().unwrap_or(sp);
  51     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  52     base::MacEager::expr(cx.expr_str(topmost, Symbol::intern(&loc.file.name.to_string())))
  53 }
  54
  55 pub fn expand_stringify(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  56                         -> Box<dyn base::MacResult+'static> {
  57     let s = pprust::tts_to_string(tts);
  58     base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&s)))
  59 }
  60
  61 pub fn expand_mod(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  62                   -> Box<dyn base::MacResult+'static> {
  63     base::check_zero_tts(cx, sp, tts, "module_path!");
  64     let mod_path = &cx.current_expansion.module.mod_path;
  65     let string = mod_path.iter().map(|x| x.to_string()).collect::<Vec<String>>().join("::");
  66
  67     base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&string)))
  68 }
  69
  70 /// include! : parse the given file as an expr
  71 /// This is generally a bad idea because it's going to behave
  72 /// unhygienically.
  73 pub fn expand_include<'cx>(cx: &'cx mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  74                            -> Box<dyn base::MacResult+'cx> {
  75     let file = match get_single_str_from_tts(cx, sp, tts, "include!") {
  76         Some(f) => f,
  77         None => return DummyResult::any(sp),
  78     };
  79     // The file will be added to the code map by the parser
  80     let file = match cx.resolve_path(file, sp) {
  81         Ok(f) => f,
  82         Err(mut err) => {
  83             err.emit();
  84             return DummyResult::any(sp);
  85         },
  86     };
  87     let directory_ownership = DirectoryOwnership::Owned { relative: None };
  88     let p = new_sub_parser_from_file(cx.parse_sess(), &file, directory_ownership, None, sp);
  89
  90     struct ExpandResult<'a> {
  91         p: Parser<'a>,
  92     }
  93     impl<'a> base::MacResult for ExpandResult<'a> {
  94         fn make_expr(mut self: Box<ExpandResult<'a>>) -> Option<P<ast::Expr>> {
  95             let r = panictry!(self.p.parse_expr());
  96             if self.p.token != token::Eof {
  97                 self.p.sess.buffer_lint(
  98                     BufferedEarlyLintId::IncompleteInclude,
  99                     self.p.token.span,
 100                     ast::CRATE_NODE_ID,
 101                     "include macro expected single expression in source",
 102                 );
 103             }
 104             Some(r)
 105         }
 106
 107         fn make_items(mut self: Box<ExpandResult<'a>>) -> Option<SmallVec<[P<ast::Item>; 1]>> {
 108             let mut ret = SmallVec::new();
 109             while self.p.token != token::Eof {
 110                 match panictry!(self.p.parse_item()) {
 111                     Some(item) => ret.push(item),
 112                     None => self.p.sess.span_diagnostic.span_fatal(self.p.token.span,
 113                                                            &format!("expected item, found `{}`",
 114                                                                     self.p.this_token_to_string()))
 115                                                .raise()
 116                 }
 117             }
 118             Some(ret)
 119         }
 120     }
 121
 122     Box::new(ExpandResult { p })
 123 }
 124
 125 // include_str! : read the given file, insert it as a literal string expr
 126 pub fn expand_include_str(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
 127                           -> Box<dyn base::MacResult+'static> {
 128     let file = match get_single_str_from_tts(cx, sp, tts, "include_str!") {
 129         Some(f) => f,
 130         None => return DummyResult::any(sp)
 131     };
 132     let file = match cx.resolve_path(file, sp) {
 133         Ok(f) => f,
 134         Err(mut err) => {
 135             err.emit();
 136             return DummyResult::any(sp);
 137         },
 138     };
 139     match cx.source_map().load_binary_file(&file) {
 140         Ok(bytes) => match std::str::from_utf8(&bytes) {
 141             Ok(src) => {
 142                 let interned_src = Symbol::intern(&src);
 143                 base::MacEager::expr(cx.expr_str(sp, interned_src))
 144             }
 145             Err(_) => {
 146                 cx.span_err(sp, &format!("{} wasn't a utf-8 file", file.display()));
 147                 DummyResult::any(sp)
 148             }
 149         },
 150         Err(e) => {
 151             cx.span_err(sp, &format!("couldn't read {}: {}", file.display(), e));
 152             DummyResult::any(sp)
 153         }
 154     }
 155 }
 156
 157 pub fn expand_include_bytes(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
 158                             -> Box<dyn base::MacResult+'static> {
 159     let file = match get_single_str_from_tts(cx, sp, tts, "include_bytes!") {
 160         Some(f) => f,
 161         None => return DummyResult::any(sp)
 162     };
 163     let file = match cx.resolve_path(file, sp) {
 164         Ok(f) => f,
 165         Err(mut err) => {
 166             err.emit();
 167             return DummyResult::any(sp);
 168         },
 169     };
 170     match cx.source_map().load_binary_file(&file) {
 171         Ok(bytes) => {
 172             base::MacEager::expr(cx.expr_lit(sp, ast::LitKind::ByteStr(Lrc::new(bytes))))
 173         },
 174         Err(e) => {
 175             cx.span_err(sp, &format!("couldn't read {}: {}", file.display(), e));
 176             DummyResult::any(sp)
 177         }
 178     }
 179 }