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     let sp = cx.with_def_site_ctxt(sp);
  25     base::check_zero_tts(cx, sp, tts, "line!");
  26
  27     let topmost = cx.expansion_cause().unwrap_or(sp);
  28     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  29
  30     base::MacEager::expr(cx.expr_u32(topmost, loc.line as u32))
  31 }
  32
  33 /* column!(): expands to the current column number */
  34 pub fn expand_column(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  35                   -> Box<dyn base::MacResult+'static> {
  36     let sp = cx.with_def_site_ctxt(sp);
  37     base::check_zero_tts(cx, sp, tts, "column!");
  38
  39     let topmost = cx.expansion_cause().unwrap_or(sp);
  40     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  41
  42     base::MacEager::expr(cx.expr_u32(topmost, loc.col.to_usize() as u32 + 1))
  43 }
  44
  45 /// file!(): expands to the current filename */
  46 /// The source_file (`loc.file`) contains a bunch more information we could spit
  47 /// out if we wanted.
  48 pub fn expand_file(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  49                    -> Box<dyn base::MacResult+'static> {
  50     let sp = cx.with_def_site_ctxt(sp);
  51     base::check_zero_tts(cx, sp, tts, "file!");
  52
  53     let topmost = cx.expansion_cause().unwrap_or(sp);
  54     let loc = cx.source_map().lookup_char_pos(topmost.lo());
  55     base::MacEager::expr(cx.expr_str(topmost, Symbol::intern(&loc.file.name.to_string())))
  56 }
  57
  58 pub fn expand_stringify(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  59                         -> Box<dyn base::MacResult+'static> {
  60     let sp = cx.with_def_site_ctxt(sp);
  61     let s = pprust::tts_to_string(tts);
  62     base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&s)))
  63 }
  64
  65 pub fn expand_mod(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  66                   -> Box<dyn base::MacResult+'static> {
  67     let sp = cx.with_def_site_ctxt(sp);
  68     base::check_zero_tts(cx, sp, tts, "module_path!");
  69     let mod_path = &cx.current_expansion.module.mod_path;
  70     let string = mod_path.iter().map(|x| x.to_string()).collect::<Vec<String>>().join("::");
  71
  72     base::MacEager::expr(cx.expr_str(sp, Symbol::intern(&string)))
  73 }
  74
  75 /// include! : parse the given file as an expr
  76 /// This is generally a bad idea because it's going to behave
  77 /// unhygienically.
  78 pub fn expand_include<'cx>(cx: &'cx mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
  79                            -> Box<dyn base::MacResult+'cx> {
  80     let sp = cx.with_def_site_ctxt(sp);
  81     let file = match get_single_str_from_tts(cx, sp, tts, "include!") {
  82         Some(f) => f,
  83         None => return DummyResult::any(sp),
  84     };
  85     // The file will be added to the code map by the parser
  86     let file = match cx.resolve_path(file, sp) {
  87         Ok(f) => f,
  88         Err(mut err) => {
  89             err.emit();
  90             return DummyResult::any(sp);
  91         },
  92     };
  93     let directory_ownership = DirectoryOwnership::Owned { relative: None };
  94     let p = new_sub_parser_from_file(cx.parse_sess(), &file, directory_ownership, None, sp);
  95
  96     struct ExpandResult<'a> {
  97         p: Parser<'a>,
  98     }
  99     impl<'a> base::MacResult for ExpandResult<'a> {
 100         fn make_expr(mut self: Box<ExpandResult<'a>>) -> Option<P<ast::Expr>> {
 101             let r = panictry!(self.p.parse_expr());
 102             if self.p.token != token::Eof {
 103                 self.p.sess.buffer_lint(
 104                     BufferedEarlyLintId::IncompleteInclude,
 105                     self.p.token.span,
 106                     ast::CRATE_NODE_ID,
 107                     "include macro expected single expression in source",
 108                 );
 109             }
 110             Some(r)
 111         }
 112
 113         fn make_items(mut self: Box<ExpandResult<'a>>) -> Option<SmallVec<[P<ast::Item>; 1]>> {
 114             let mut ret = SmallVec::new();
 115             while self.p.token != token::Eof {
 116                 match panictry!(self.p.parse_item()) {
 117                     Some(item) => ret.push(item),
 118                     None => self.p.sess.span_diagnostic.span_fatal(self.p.token.span,
 119                                                            &format!("expected item, found `{}`",
 120                                                                     self.p.this_token_to_string()))
 121                                                .raise()
 122                 }
 123             }
 124             Some(ret)
 125         }
 126     }
 127
 128     Box::new(ExpandResult { p })
 129 }
 130
 131 // include_str! : read the given file, insert it as a literal string expr
 132 pub fn expand_include_str(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
 133                           -> Box<dyn base::MacResult+'static> {
 134     let sp = cx.with_def_site_ctxt(sp);
 135     let file = match get_single_str_from_tts(cx, sp, tts, "include_str!") {
 136         Some(f) => f,
 137         None => return DummyResult::any(sp)
 138     };
 139     let file = match cx.resolve_path(file, sp) {
 140         Ok(f) => f,
 141         Err(mut err) => {
 142             err.emit();
 143             return DummyResult::any(sp);
 144         },
 145     };
 146     match cx.source_map().load_binary_file(&file) {
 147         Ok(bytes) => match std::str::from_utf8(&bytes) {
 148             Ok(src) => {
 149                 let interned_src = Symbol::intern(&src);
 150                 base::MacEager::expr(cx.expr_str(sp, interned_src))
 151             }
 152             Err(_) => {
 153                 cx.span_err(sp, &format!("{} wasn't a utf-8 file", file.display()));
 154                 DummyResult::any(sp)
 155             }
 156         },
 157         Err(e) => {
 158             cx.span_err(sp, &format!("couldn't read {}: {}", file.display(), e));
 159             DummyResult::any(sp)
 160         }
 161     }
 162 }
 163
 164 pub fn expand_include_bytes(cx: &mut ExtCtxt<'_>, sp: Span, tts: TokenStream)
 165                             -> Box<dyn base::MacResult+'static> {
 166     let sp = cx.with_def_site_ctxt(sp);
 167     let file = match get_single_str_from_tts(cx, sp, tts, "include_bytes!") {
 168         Some(f) => f,
 169         None => return DummyResult::any(sp)
 170     };
 171     let file = match cx.resolve_path(file, sp) {
 172         Ok(f) => f,
 173         Err(mut err) => {
 174             err.emit();
 175             return DummyResult::any(sp);
 176         },
 177     };
 178     match cx.source_map().load_binary_file(&file) {
 179         Ok(bytes) => {
 180             base::MacEager::expr(cx.expr_lit(sp, ast::LitKind::ByteStr(Lrc::new(bytes))))
 181         },
 182         Err(e) => {
 183             cx.span_err(sp, &format!("couldn't read {}: {}", file.display(), e));
 184             DummyResult::any(sp)
 185         }
 186     }
 187 }