Auto merge of #65324 - Centril:organize-syntax, r=petrochenkov

Split libsyntax apart

In this PR the general idea is to separate the AST, parser, and friends by a more data / logic structure (tho not fully realized!) by separating out the parser and macro expansion code from libsyntax. Specifically have now three crates instead of one (libsyntax):

- libsyntax:

   - concrete syntax tree (`syntax::ast`)

   - definition of tokens and token-streams (`syntax::{token, tokenstream}`) -- used by `syntax::ast`

   - visitors (`syntax::visit`, `syntax::mut_visit`)

   - shared definitions between `libsyntax_expand`

   - feature gating (`syntax::feature_gate`) -- we could possibly move this out to its own crater later.

   - attribute and meta item utilities, including used-marking (`syntax::attr`)

   - pretty printer (`syntax::print`) -- this should possibly be moved out later. For now I've reduced down the dependencies to a single essential one which could be broken via `ParseSess`. This entails that e.g. `Debug` impls for `Path` cannot reference the pretty printer.

   - definition of `ParseSess` (`syntax::sess`) -- this is used by `syntax::{attr, print, feature_gate}` and is a common definition used by the parser and other things like librustc.

   - the `syntax::source_map` -- this includes definitions used by `syntax::ast` and other things but could ostensibly be moved `syntax_pos` since that is more related to this module.

   - a smattering of misc utilities not sufficiently important to itemize -- some of these could be moved to where they are used (often a single place) but I wanted to limit the scope of this PR.

- librustc_parse:

   - parser (`rustc_parse::parser`) -- reading a file and such are defined in the crate root tho.

   - lexer (`rustc_parse::lexer`)

   - validation of meta grammar (post-expansion) in (`rustc_parse::validate_attr`)

- libsyntax_expand -- this defines the infra for macro expansion and conditional compilation but this is not libsyntax_ext; we might want to merge them later but currently libsyntax_expand is depended on by librustc_metadata which libsyntax_ext is not.

   - conditional compilation (`syntax_expand::config`) -- moved from `syntax::config` to here

   - the bulk of this crate is made up of the old `syntax::ext`

r? @estebank

1 files changed, 0 insertions, 339 deletions

diff --git a/src/libsyntax/parse/tests.rs b/src/libsyntax/parse/tests.rs
deleted file mode 100644
index 27ca2b6472f..00000000000
--- a/src/libsyntax/parse/tests.rs
+++ /dev/null
@@ -1,339 +0,0 @@
-use super::*;
-
-use crate::ast::{self, Name, PatKind};
-use crate::attr::first_attr_value_str_by_name;
-use crate::sess::ParseSess;
-use crate::parse::{PResult, new_parser_from_source_str};
-use crate::token::Token;
-use crate::print::pprust::item_to_string;
-use crate::ptr::P;
-use crate::source_map::FilePathMapping;
-use crate::symbol::{kw, sym};
-use crate::tests::{matches_codepattern, string_to_stream, with_error_checking_parse};
-use crate::tokenstream::{DelimSpan, TokenTree, TokenStream};
-use crate::with_default_globals;
-use syntax_pos::{Span, BytePos, Pos};
-
-use std::path::PathBuf;
-
-/// Parses an item.
-///
-/// Returns `Ok(Some(item))` when successful, `Ok(None)` when no item was found, and `Err`
-/// when a syntax error occurred.
-fn parse_item_from_source_str(name: FileName, source: String, sess: &ParseSess)
-                                    -> PResult<'_, Option<P<ast::Item>>> {
-    new_parser_from_source_str(sess, name, source).parse_item()
-}
-
-// Produces a `syntax_pos::span`.
-fn sp(a: u32, b: u32) -> Span {
-    Span::with_root_ctxt(BytePos(a), BytePos(b))
-}
-
-/// Parses a string, return an expression.
-fn string_to_expr(source_str : String) -> P<ast::Expr> {
-    let ps = ParseSess::new(FilePathMapping::empty());
-    with_error_checking_parse(source_str, &ps, |p| {
-        p.parse_expr()
-    })
-}
-
-/// Parses a string, returns an item.
-fn string_to_item(source_str : String) -> Option<P<ast::Item>> {
-    let ps = ParseSess::new(FilePathMapping::empty());
-    with_error_checking_parse(source_str, &ps, |p| {
-        p.parse_item()
-    })
-}
-
-#[should_panic]
-#[test] fn bad_path_expr_1() {
-    with_default_globals(|| {
-        string_to_expr("::abc::def::return".to_string());
-    })
-}
-
-// Checks the token-tree-ization of macros.
-#[test]
-fn string_to_tts_macro () {
-    with_default_globals(|| {
-        let tts: Vec<_> =
-            string_to_stream("macro_rules! zip (($a)=>($a))".to_string()).trees().collect();
-        let tts: &[TokenTree] = &tts[..];
-
-        match tts {
-            [
-                TokenTree::Token(Token { kind: token::Ident(name_macro_rules, false), .. }),
-                TokenTree::Token(Token { kind: token::Not, .. }),
-                TokenTree::Token(Token { kind: token::Ident(name_zip, false), .. }),
-                TokenTree::Delimited(_, macro_delim,  macro_tts)
-            ]
-            if name_macro_rules == &sym::macro_rules && name_zip.as_str() == "zip" => {
-                let tts = &macro_tts.trees().collect::<Vec<_>>();
-                match &tts[..] {
-                    [
-                        TokenTree::Delimited(_, first_delim, first_tts),
-                        TokenTree::Token(Token { kind: token::FatArrow, .. }),
-                        TokenTree::Delimited(_, second_delim, second_tts),
-                    ]
-                    if macro_delim == &token::Paren => {
-                        let tts = &first_tts.trees().collect::<Vec<_>>();
-                        match &tts[..] {
-                            [
-                                TokenTree::Token(Token { kind: token::Dollar, .. }),
-                                TokenTree::Token(Token { kind: token::Ident(name, false), .. }),
-                            ]
-                            if first_delim == &token::Paren && name.as_str() == "a" => {},
-                            _ => panic!("value 3: {:?} {:?}", first_delim, first_tts),
-                        }
-                        let tts = &second_tts.trees().collect::<Vec<_>>();
-                        match &tts[..] {
-                            [
-                                TokenTree::Token(Token { kind: token::Dollar, .. }),
-                                TokenTree::Token(Token { kind: token::Ident(name, false), .. }),
-                            ]
-                            if second_delim == &token::Paren && name.as_str() == "a" => {},
-                            _ => panic!("value 4: {:?} {:?}", second_delim, second_tts),
-                        }
-                    },
-                    _ => panic!("value 2: {:?} {:?}", macro_delim, macro_tts),
-                }
-            },
-            _ => panic!("value: {:?}",tts),
-        }
-    })
-}
-
-#[test]
-fn string_to_tts_1() {
-    with_default_globals(|| {
-        let tts = string_to_stream("fn a (b : i32) { b; }".to_string());
-
-        let expected = TokenStream::new(vec![
-            TokenTree::token(token::Ident(kw::Fn, false), sp(0, 2)).into(),
-            TokenTree::token(token::Ident(Name::intern("a"), false), sp(3, 4)).into(),
-            TokenTree::Delimited(
-                DelimSpan::from_pair(sp(5, 6), sp(13, 14)),
-                token::DelimToken::Paren,
-                TokenStream::new(vec![
-                    TokenTree::token(token::Ident(Name::intern("b"), false), sp(6, 7)).into(),
-                    TokenTree::token(token::Colon, sp(8, 9)).into(),
-                    TokenTree::token(token::Ident(sym::i32, false), sp(10, 13)).into(),
-                ]).into(),
-            ).into(),
-            TokenTree::Delimited(
-                DelimSpan::from_pair(sp(15, 16), sp(20, 21)),
-                token::DelimToken::Brace,
-                TokenStream::new(vec![
-                    TokenTree::token(token::Ident(Name::intern("b"), false), sp(17, 18)).into(),
-                    TokenTree::token(token::Semi, sp(18, 19)).into(),
-                ]).into(),
-            ).into()
-        ]);
-
-        assert_eq!(tts, expected);
-    })
-}
-
-#[test] fn parse_use() {
-    with_default_globals(|| {
-        let use_s = "use foo::bar::baz;";
-        let vitem = string_to_item(use_s.to_string()).unwrap();
-        let vitem_s = item_to_string(&vitem);
-        assert_eq!(&vitem_s[..], use_s);
-
-        let use_s = "use foo::bar as baz;";
-        let vitem = string_to_item(use_s.to_string()).unwrap();
-        let vitem_s = item_to_string(&vitem);
-        assert_eq!(&vitem_s[..], use_s);
-    })
-}
-
-#[test] fn parse_extern_crate() {
-    with_default_globals(|| {
-        let ex_s = "extern crate foo;";
-        let vitem = string_to_item(ex_s.to_string()).unwrap();
-        let vitem_s = item_to_string(&vitem);
-        assert_eq!(&vitem_s[..], ex_s);
-
-        let ex_s = "extern crate foo as bar;";
-        let vitem = string_to_item(ex_s.to_string()).unwrap();
-        let vitem_s = item_to_string(&vitem);
-        assert_eq!(&vitem_s[..], ex_s);
-    })
-}
-
-fn get_spans_of_pat_idents(src: &str) -> Vec<Span> {
-    let item = string_to_item(src.to_string()).unwrap();
-
-    struct PatIdentVisitor {
-        spans: Vec<Span>
-    }
-    impl<'a> crate::visit::Visitor<'a> for PatIdentVisitor {
-        fn visit_pat(&mut self, p: &'a ast::Pat) {
-            match p.kind {
-                PatKind::Ident(_ , ref ident, _) => {
-                    self.spans.push(ident.span.clone());
-                }
-                _ => {
-                    crate::visit::walk_pat(self, p);
-                }
-            }
-        }
-    }
-    let mut v = PatIdentVisitor { spans: Vec::new() };
-    crate::visit::walk_item(&mut v, &item);
-    return v.spans;
-}
-
-#[test] fn span_of_self_arg_pat_idents_are_correct() {
-    with_default_globals(|| {
-
-        let srcs = ["impl z { fn a (&self, &myarg: i32) {} }",
-                    "impl z { fn a (&mut self, &myarg: i32) {} }",
-                    "impl z { fn a (&'a self, &myarg: i32) {} }",
-                    "impl z { fn a (self, &myarg: i32) {} }",
-                    "impl z { fn a (self: Foo, &myarg: i32) {} }",
-                    ];
-
-        for &src in &srcs {
-            let spans = get_spans_of_pat_idents(src);
-            let (lo, hi) = (spans[0].lo(), spans[0].hi());
-            assert!("self" == &src[lo.to_usize()..hi.to_usize()],
-                    "\"{}\" != \"self\". src=\"{}\"",
-                    &src[lo.to_usize()..hi.to_usize()], src)
-        }
-    })
-}
-
-#[test] fn parse_exprs () {
-    with_default_globals(|| {
-        // just make sure that they parse....
-        string_to_expr("3 + 4".to_string());
-        string_to_expr("a::z.froob(b,&(987+3))".to_string());
-    })
-}
-
-#[test] fn attrs_fix_bug () {
-    with_default_globals(|| {
-        string_to_item("pub fn mk_file_writer(path: &Path, flags: &[FileFlag])
-                -> Result<Box<Writer>, String> {
-#[cfg(windows)]
-fn wb() -> c_int {
-    (O_WRONLY | libc::consts::os::extra::O_BINARY) as c_int
-}
-
-#[cfg(unix)]
-fn wb() -> c_int { O_WRONLY as c_int }
-
-let mut fflags: c_int = wb();
-}".to_string());
-    })
-}
-
-#[test] fn crlf_doc_comments() {
-    with_default_globals(|| {
-        let sess = ParseSess::new(FilePathMapping::empty());
-
-        let name_1 = FileName::Custom("crlf_source_1".to_string());
-        let source = "/// doc comment\r\nfn foo() {}".to_string();
-        let item = parse_item_from_source_str(name_1, source, &sess)
-            .unwrap().unwrap();
-        let doc = first_attr_value_str_by_name(&item.attrs, sym::doc).unwrap();
-        assert_eq!(doc.as_str(), "/// doc comment");
-
-        let name_2 = FileName::Custom("crlf_source_2".to_string());
-        let source = "/// doc comment\r\n/// line 2\r\nfn foo() {}".to_string();
-        let item = parse_item_from_source_str(name_2, source, &sess)
-            .unwrap().unwrap();
-        let docs = item.attrs.iter().filter(|a| a.has_name(sym::doc))
-                    .map(|a| a.value_str().unwrap().to_string()).collect::<Vec<_>>();
-        let b: &[_] = &["/// doc comment".to_string(), "/// line 2".to_string()];
-        assert_eq!(&docs[..], b);
-
-        let name_3 = FileName::Custom("clrf_source_3".to_string());
-        let source = "/** doc comment\r\n *  with CRLF */\r\nfn foo() {}".to_string();
-        let item = parse_item_from_source_str(name_3, source, &sess).unwrap().unwrap();
-        let doc = first_attr_value_str_by_name(&item.attrs, sym::doc).unwrap();
-        assert_eq!(doc.as_str(), "/** doc comment\n *  with CRLF */");
-    });
-}
-
-#[test]
-fn ttdelim_span() {
-    fn parse_expr_from_source_str(
-        name: FileName, source: String, sess: &ParseSess
-    ) -> PResult<'_, P<ast::Expr>> {
-        new_parser_from_source_str(sess, name, source).parse_expr()
-    }
-
-    with_default_globals(|| {
-        let sess = ParseSess::new(FilePathMapping::empty());
-        let expr = parse_expr_from_source_str(PathBuf::from("foo").into(),
-            "foo!( fn main() { body } )".to_string(), &sess).unwrap();
-
-        let tts: Vec<_> = match expr.kind {
-            ast::ExprKind::Mac(ref mac) => mac.stream().trees().collect(),
-            _ => panic!("not a macro"),
-        };
-
-        let span = tts.iter().rev().next().unwrap().span();
-
-        match sess.source_map().span_to_snippet(span) {
-            Ok(s) => assert_eq!(&s[..], "{ body }"),
-            Err(_) => panic!("could not get snippet"),
-        }
-    });
-}
-
-// This tests that when parsing a string (rather than a file) we don't try
-// and read in a file for a module declaration and just parse a stub.
-// See `recurse_into_file_modules` in the parser.
-#[test]
-fn out_of_line_mod() {
-    with_default_globals(|| {
-        let sess = ParseSess::new(FilePathMapping::empty());
-        let item = parse_item_from_source_str(
-            PathBuf::from("foo").into(),
-            "mod foo { struct S; mod this_does_not_exist; }".to_owned(),
-            &sess,
-        ).unwrap().unwrap();
-
-        if let ast::ItemKind::Mod(ref m) = item.kind {
-            assert!(m.items.len() == 2);
-        } else {
-            panic!();
-        }
-    });
-}
-
-#[test]
-fn eqmodws() {
-    assert_eq!(matches_codepattern("",""),true);
-    assert_eq!(matches_codepattern("","a"),false);
-    assert_eq!(matches_codepattern("a",""),false);
-    assert_eq!(matches_codepattern("a","a"),true);
-    assert_eq!(matches_codepattern("a b","a   \n\t\r  b"),true);
-    assert_eq!(matches_codepattern("a b ","a   \n\t\r  b"),true);
-    assert_eq!(matches_codepattern("a b","a   \n\t\r  b "),false);
-    assert_eq!(matches_codepattern("a   b","a b"),true);
-    assert_eq!(matches_codepattern("ab","a b"),false);
-    assert_eq!(matches_codepattern("a   b","ab"),true);
-    assert_eq!(matches_codepattern(" a   b","ab"),true);
-}
-
-#[test]
-fn pattern_whitespace() {
-    assert_eq!(matches_codepattern("","\x0C"), false);
-    assert_eq!(matches_codepattern("a b ","a   \u{0085}\n\t\r  b"),true);
-    assert_eq!(matches_codepattern("a b","a   \u{0085}\n\t\r  b "),false);
-}
-
-#[test]
-fn non_pattern_whitespace() {
-    // These have the property 'White_Space' but not 'Pattern_White_Space'
-    assert_eq!(matches_codepattern("a b","a\u{2002}b"), false);
-    assert_eq!(matches_codepattern("a   b","a\u{2002}b"), false);
-    assert_eq!(matches_codepattern("\u{205F}a   b","ab"), false);
-    assert_eq!(matches_codepattern("a  \u{3000}b","ab"), false);
-}