Rollup merge of #63761 - petrochenkov:procattrs, r=eddyb

Propagate spans and attributes from proc macro definitions

Thanks to https://github.com/rust-lang/rust/pull/63269 we now have spans and attributes from proc macro definitions available in metadata.

However, that PR didn't actually put them into use! This PR finishes that work.

Attributes `rustc_macro_transparency`, `allow_internal_unstable`, `allow_internal_unsafe`, `local_inner_macros`, `rustc_builtin_macro`, `stable`, `unstable`, `rustc_deprecated`, `deprecated` now have effect when applied to proc macro definition functions.
From those attributes only `deprecated` is both stable and supposed to be used in new code.
(`#![staged_api]` still cannot be used in proc macro crates for unrelated reasons though.)

`Span::def_site` from the proc macro API now returns the correct location of the proc macro definition.

Also, I made a mistake in https://github.com/rust-lang/rust/pull/63269#discussion_r312702919, loaded proc macros didn't actually use the resolver cache.
This PR fixes the caching issue, now proc macros go through the `Resolver::macro_map` cache as well.

(Also, the first commit turns `proc_macro::quote` into a regular built-in macro to reduce the number of places where `SyntaxExtension`s need to be manually created.)

1 files changed, 5 insertions, 4 deletions

diff --git a/src/libsyntax/parse/parser.rs b/src/libsyntax/parse/parser.rs
index 25ad2d4404c..2b20cb88796 100644
--- a/src/libsyntax/parse/parser.rs
+++ b/src/libsyntax/parse/parser.rs
@@ -375,10 +375,11 @@ impl<'a> Parser<'a> {
         if let Some(directory) = directory {
             parser.directory = directory;
         } else if !parser.token.span.is_dummy() {
-            if let FileName::Real(mut path) =
-                    sess.source_map().span_to_unmapped_path(parser.token.span) {
-                path.pop();
-                parser.directory.path = Cow::from(path);
+            if let Some(FileName::Real(path)) =
+                    &sess.source_map().lookup_char_pos(parser.token.span.lo()).file.unmapped_path {
+                if let Some(directory_path) = path.parent() {
+                    parser.directory.path = Cow::from(directory_path.to_path_buf());
+                }
             }
         }