Fix links (#549)

Author: JohnTitor

src/appendix/code-index.md

@@ -21,9 +21,9 @@ Item            |  Kind    | Short description           | Chapter            |
 `Query` | struct | Represents the result of query to the `Compiler` interface and allows stealing, borrowing, and returning the results of compiler passes. | [The Rustc Driver and Interface] | [src/librustc_interface/queries.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_interface/queries/struct.Query.html)
 `Rib` | struct | Represents a single scope of names | [Name resolution] | [src/librustc_resolve/lib.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_resolve/late/struct.Rib.html)
 `Session` | struct | The data associated with a compilation session | [The parser], [The Rustc Driver and Interface] | [src/librustc/session/mod.html](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_session/struct.Session.html)
-`SourceFile` | struct | Part of the `SourceMap`. Maps AST nodes to their source code for a single source file. Was previously called FileMap | [The parser] | [src/libsyntax_pos/lib.rs](https://doc.rust-lang.org/nightly/nightly-rustc/syntax/source_map/struct.SourceFile.html)
+`SourceFile` | struct | Part of the `SourceMap`. Maps AST nodes to their source code for a single source file. Was previously called FileMap | [The parser] | [src/librustc_span/lib.rs](https://doc.rust-lang.org/nightly/nightly-rustc/syntax/source_map/struct.SourceFile.html)
 `SourceMap` | struct | Maps AST nodes to their source code. It is composed of `SourceFile`s. Was previously called CodeMap | [The parser] | [src/libsyntax/source_map.rs](https://doc.rust-lang.org/nightly/nightly-rustc/syntax/source_map/struct.SourceMap.html)
-`Span` | struct  | A location in the user's source code, used for error reporting primarily | [Emitting Diagnostics] | [src/libsyntax_pos/span_encoding.rs](https://doc.rust-lang.org/nightly/nightly-rustc/syntax_pos/struct.Span.html)
+`Span` | struct  | A location in the user's source code, used for error reporting primarily | [Emitting Diagnostics] | [src/librustc_span/span_encoding.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_span/struct.Span.html)
 `StringReader` | struct | This is the lexer used during parsing. It consumes characters from the raw source code being compiled and produces a series of tokens for use by the rest of the parser | [The parser] |  [src/librustc_parse/lexer/mod.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc_parse/lexer/struct.StringReader.html)
 `syntax::token_stream::TokenStream` | struct | An abstract sequence of tokens, organized into `TokenTree`s | [The parser], [Macro expansion] | [src/libsyntax/tokenstream.rs](https://doc.rust-lang.org/nightly/nightly-rustc/syntax/tokenstream/struct.TokenStream.html)
 `TraitDef` | struct | This struct contains a trait's definition with type information | [The `ty` modules] |  [src/librustc/ty/trait_def.rs](https://doc.rust-lang.org/nightly/nightly-rustc/rustc/ty/trait_def/struct.TraitDef.html)

src/high-level-overview.md

@@ -36,7 +36,7 @@ rustc_codegen  rustc_borrowck   ...  rustc_metadata
                     syntax
                     /    \
                   /       \
-           syntax_pos  syntax_ext
+           rustc_span  rustc_builtin_macros
 ```
 
 The `rustc_driver` crate, at the top of this lattice, is effectively

src/macro-expansion.md

@@ -1,6 +1,6 @@
 # Macro expansion
 
-> `libsyntax`, `librustc_expand`, and `libsyntax_ext` are all undergoing
+> `libsyntax`, `librustc_expand`, and `librustc_builtin_macros` are all undergoing
 > refactoring, so some of the links in this chapter may be broken.
 
 Macro expansion happens during parsing. `rustc` has two parsers, in fact: the
@@ -10,7 +10,7 @@ before name resolution, macros are expanded using these portions of the code.
 The macro parser, in turn, may call the normal Rust parser when it needs to
 bind a metavariable (e.g.  `$my_expr`) while parsing the contents of a macro
 invocation. The code for macro expansion is in
-[`src/libsyntax_expand/mbe/`][code_dir]. This chapter aims to explain how macro
+[`src/librustc_expand/mbe/`][code_dir]. This chapter aims to explain how macro
 expansion works.
 
 ### Example
@@ -64,7 +64,7 @@ invocations. Interestingly, both are done by the macro parser.
 Basically, the macro parser is like an NFA-based regex parser. It uses an
 algorithm similar in spirit to the [Earley parsing
 algorithm](https://en.wikipedia.org/wiki/Earley_parser). The macro parser is
-defined in [`src/libsyntax_expand/mbe/macro_parser.rs`][code_mp].
+defined in [`src/librustc_expand/mbe/macro_parser.rs`][code_mp].
 
 The interface of the macro parser is as follows (this is slightly simplified):
 
@@ -113,7 +113,7 @@ normal Rust parser.
 As mentioned above, both definitions and invocations of macros are parsed using
 the macro parser. This is extremely non-intuitive and self-referential. The code
 to parse macro _definitions_ is in
-[`src/libsyntax_expand/mbe/macro_rules.rs`][code_mr]. It defines the pattern for
+[`src/librustc_expand/mbe/macro_rules.rs`][code_mr]. It defines the pattern for
 matching for a macro definition as `$( $lhs:tt => $rhs:tt );+`. In other words,
 a `macro_rules` definition should have in its body at least one occurrence of a
 token tree followed by `=>` followed by another token tree. When the compiler
@@ -142,7 +142,7 @@ the parse is ambiguous, while if there are no matches at all, there is a syntax
 error.
 
 For more information about the macro parser's implementation, see the comments
-in [`src/libsyntax_expand/mbe/macro_parser.rs`][code_mp].
+in [`src/librustc_expand/mbe/macro_parser.rs`][code_mp].
 
 ### Hygiene
 
@@ -208,10 +208,10 @@ TODO
 TODO: maybe something about macros 2.0?
 
 
-[code_dir]: https://github.com./rust-lang/rust/tree/master/src/libsyntax_expand/mbe
-[code_mp]: https://doc.rust-lang.org/nightly/nightly-rustc/syntax_expand/mbe/macro_parser
-[code_mr]: https://doc.rust-lang.org/nightly/nightly-rustc/syntax_expand/mbe/macro_rules
-[code_parse_int]: https://doc.rust-lang.org/nightly/nightly-rustc/syntax_expand/mbe/macro_parser/fn.parse.html
+[code_dir]: https://github.com./rust-lang/rust/tree/master/src/librustc_expand/mbe
+[code_mp]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_expand/mbe/macro_parser
+[code_mr]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_expand/mbe/macro_rules
+[code_parse_int]: https://doc.rust-lang.org/nightly/nightly-rustc/rustc_expand/mbe/macro_parser/fn.parse.html
 [parsing]: ./the-parser.html
 
 
@@ -356,11 +356,11 @@ Vadim Petrochenkov: Here's some preliminary data I prepared.
 
 Vadim Petrochenkov: Below I'll assume #62771 and #62086 has landed.
 
-Vadim Petrochenkov: Where to find the code: libsyntax_pos/hygiene.rs -
+Vadim Petrochenkov: Where to find the code: librustc_span/hygiene.rs -
 structures related to hygiene and expansion that are kept in global data (can
-be accessed from any Ident without any context) libsyntax_pos/lib.rs - some
+be accessed from any Ident without any context) librustc_span/lib.rs - some
 secondary methods like macro backtrace using primary methods from hygiene.rs
-libsyntax_ext - implementations of built-in macros (including macro attributes
+librustc_builtin_macros - implementations of built-in macros (including macro attributes
 and derives) and some other early code generation facilities like injection of
 standard library imports or generation of test harness.  libsyntax/config.rs -
 implementation of cfg/cfg_attr (they treated specially from other macros),
@@ -375,8 +375,8 @@ AST libsyntax/ext/placeholder.rs - the part of expand.rs responsible for
 "integrating the results back into AST" basicallly, "placeholder" is a
 temporary AST node replaced with macro expansion result nodes
 libsyntax/ext/builer.rs - helper functions for building AST for built-in macros
-in libsyntax_ext (and user-defined syntactic plugins previously), can probably
-be moved into libsyntax_ext these days libsyntax/ext/proc_macro.rs +
+in librustc_builtin_macros (and user-defined syntactic plugins previously), can probably
+be moved into librustc_builtin_macros these days libsyntax/ext/proc_macro.rs +
 libsyntax/ext/proc_macro_server.rs - interfaces between the compiler and the
 stable proc_macro library, converting tokens and token streams between the two
 representations and sending them through C ABI libsyntax/ext/tt -