proc_macro: remove the __internal module.

eddyb · eddyb · commit 38fee305dac4 · 2018-11-30T06:15:19.000+02:00
diff --git a/src/libproc_macro/lib.rs b/src/libproc_macro/lib.rs
@@ -1145,101 +1145,3 @@ impl fmt::Debug for Literal {
         self.0.fmt(f)
     }
 }
-
-/// Permanently unstable internal implementation details of this crate. This
-/// should not be used.
-///
-/// These methods are used by the rest of the compiler to generate instances of
-/// `TokenStream` to hand to macro definitions, as well as consume the output.
-///
-/// Note that this module is also intentionally separate from the rest of the
-/// crate. This allows the `#[unstable]` directive below to naturally apply to
-/// all of the contents.
-#[unstable(feature = "proc_macro_internals", issue = "27812")]
-#[doc(hidden)]
-pub mod __internal {
-    use std::cell::Cell;
-    use std::ptr;
-
-    use syntax::errors::DiagnosticBuilder;
-    use syntax::ext::base::ExtCtxt;
-    use syntax::parse::ParseSess;
-    use syntax_pos::{BytePos, Loc, DUMMY_SP, Span};
-    use syntax_pos::hygiene::{SyntaxContext, Transparency};
-
-    use super::LexError;
-
-    pub fn lookup_char_pos(pos: BytePos) -> Loc {
-        with_sess(|sess, _| sess.source_map().lookup_char_pos(pos))
-    }
-
-    pub fn parse_to_lex_err(mut err: DiagnosticBuilder) -> LexError {
-        err.cancel();
-        LexError { _inner: () }
-    }
-
-    #[derive(Clone, Copy)]
-    pub struct ProcMacroData {
-        pub def_site: Span,
-        pub call_site: Span,
-    }
-
-    #[derive(Clone, Copy)]
-    struct ProcMacroSess {
-        parse_sess: *const ParseSess,
-        data: ProcMacroData,
-    }
-
-    // Emulate scoped_thread_local!() here essentially
-    thread_local! {
-        static CURRENT_SESS: Cell<ProcMacroSess> = Cell::new(ProcMacroSess {
-            parse_sess: ptr::null(),
-            data: ProcMacroData { def_site: DUMMY_SP, call_site: DUMMY_SP },
-        });
-    }
-
-    pub fn set_sess<F, R>(cx: &ExtCtxt, f: F) -> R
-        where F: FnOnce() -> R
-    {
-        struct Reset { prev: ProcMacroSess }
-
-        impl Drop for Reset {
-            fn drop(&mut self) {
-                CURRENT_SESS.with(|p| p.set(self.prev));
-            }
-        }
-
-        CURRENT_SESS.with(|p| {
-            let _reset = Reset { prev: p.get() };
-
-            // No way to determine def location for a proc macro right now, so use call location.
-            let location = cx.current_expansion.mark.expn_info().unwrap().call_site;
-            let to_span = |transparency| location.with_ctxt(
-                SyntaxContext::empty().apply_mark_with_transparency(cx.current_expansion.mark,
-                                                                    transparency));
-            p.set(ProcMacroSess {
-                parse_sess: cx.parse_sess,
-                data: ProcMacroData {
-                    def_site: to_span(Transparency::Opaque),
-                    call_site: to_span(Transparency::Transparent),
-                },
-            });
-            f()
-        })
-    }
-
-    pub fn in_sess() -> bool
-    {
-        !CURRENT_SESS.with(|sess| sess.get()).parse_sess.is_null()
-    }
-
-    pub fn with_sess<F, R>(f: F) -> R
-        where F: FnOnce(&ParseSess, &ProcMacroData) -> R
-    {
-        let sess = CURRENT_SESS.with(|sess| sess.get());
-        if sess.parse_sess.is_null() {
-            panic!("procedural macro API is used outside of a procedural macro");
-        }
-        f(unsafe { &*sess.parse_sess }, &sess.data)
-    }
-}
diff --git a/src/libproc_macro/rustc.rs b/src/libproc_macro/rustc.rs
@@ -9,16 +9,18 @@
 // except according to those terms.
 
 use bridge::{server, TokenTree};
-use {Delimiter, Level, LineColumn, Spacing, __internal};
+use {Delimiter, Level, LineColumn, Spacing};
 
 use rustc_data_structures::sync::Lrc;
 use rustc_errors::{self as errors, Diagnostic, DiagnosticBuilder};
 use std::ascii;
 use std::ops::Bound;
 use syntax::ast;
+use syntax::ext::base::ExtCtxt;
 use syntax::parse::lexer::comments;
-use syntax::parse::{self, token};
+use syntax::parse::{self, token, ParseSess};
 use syntax::tokenstream::{self, DelimSpan, TokenStream};
+use syntax_pos::hygiene::{SyntaxContext, Transparency};
 use syntax_pos::symbol::{keywords, Symbol};
 use syntax_pos::{BytePos, FileName, MultiSpan, Pos, SourceFile, Span};
 
@@ -43,7 +45,7 @@ impl Delimiter {
 }
 
 impl TokenTree<Group, Punct, Ident, Literal> {
-    fn from_internal(stream: TokenStream, stack: &mut Vec<Self>) -> Self {
+    fn from_internal(stream: TokenStream, sess: &ParseSess, stack: &mut Vec<Self>) -> Self {
         use syntax::parse::token::*;
 
         let (tree, joint) = stream.as_tree();
@@ -188,14 +190,14 @@ impl TokenTree<Group, Punct, Ident, Literal> {
                 })
             }
 
-            Interpolated(_) => __internal::with_sess(|sess, _| {
+            Interpolated(_) => {
                 let stream = token.interpolated_to_tokenstream(sess, span);
                 TokenTree::Group(Group {
                     delimiter: Delimiter::None,
                     stream,
                     span: DelimSpan::from_single(span),
                 })
-            }),
+            }
 
             DotEq => op!('.', '='),
             OpenDelim(..) | CloseDelim(..) => unreachable!(),
@@ -337,9 +339,31 @@ pub struct Literal {
     span: Span,
 }
 
-pub struct Rustc;
+pub struct Rustc<'a> {
+    sess: &'a ParseSess,
+    def_site: Span,
+    call_site: Span,
+}
+
+impl<'a> Rustc<'a> {
+    pub fn new(cx: &'a ExtCtxt) -> Self {
+        // No way to determine def location for a proc macro right now, so use call location.
+        let location = cx.current_expansion.mark.expn_info().unwrap().call_site;
+        let to_span = |transparency| {
+            location.with_ctxt(
+                SyntaxContext::empty()
+                    .apply_mark_with_transparency(cx.current_expansion.mark, transparency),
+            )
+        };
+        Rustc {
+            sess: cx.parse_sess,
+            def_site: to_span(Transparency::Opaque),
+            call_site: to_span(Transparency::Transparent),
+        }
+    }
+}
 
-impl server::Types for Rustc {
+impl server::Types for Rustc<'_> {
     type TokenStream = TokenStream;
     type TokenStreamBuilder = tokenstream::TokenStreamBuilder;
     type TokenStreamIter = TokenStreamIter;
@@ -353,22 +377,20 @@ impl server::Types for Rustc {
     type Span = Span;
 }
 
-impl server::TokenStream for Rustc {
+impl server::TokenStream for Rustc<'_> {
     fn new(&mut self) -> Self::TokenStream {
         TokenStream::empty()
     }
     fn is_empty(&mut self, stream: &Self::TokenStream) -> bool {
         stream.is_empty()
     }
     fn from_str(&mut self, src: &str) -> Self::TokenStream {
-        ::__internal::with_sess(|sess, data| {
-            parse::parse_stream_from_source_str(
-                FileName::ProcMacroSourceCode,
-                src.to_string(),
-                sess,
-                Some(data.call_site),
-            )
-        })
+        parse::parse_stream_from_source_str(
+            FileName::ProcMacroSourceCode,
+            src.to_string(),
+            self.sess,
+            Some(self.call_site),
+        )
     }
     fn to_string(&mut self, stream: &Self::TokenStream) -> String {
         stream.to_string()
@@ -387,7 +409,7 @@ impl server::TokenStream for Rustc {
     }
 }
 
-impl server::TokenStreamBuilder for Rustc {
+impl server::TokenStreamBuilder for Rustc<'_> {
     fn new(&mut self) -> Self::TokenStreamBuilder {
         tokenstream::TokenStreamBuilder::new()
     }
@@ -399,15 +421,15 @@ impl server::TokenStreamBuilder for Rustc {
     }
 }
 
-impl server::TokenStreamIter for Rustc {
+impl server::TokenStreamIter for Rustc<'_> {
     fn next(
         &mut self,
         iter: &mut Self::TokenStreamIter,
     ) -> Option<TokenTree<Self::Group, Self::Punct, Self::Ident, Self::Literal>> {
         loop {
             let tree = iter.stack.pop().or_else(|| {
                 let next = iter.cursor.next_as_stream()?;
-                Some(TokenTree::from_internal(next, &mut iter.stack))
+                Some(TokenTree::from_internal(next, self.sess, &mut iter.stack))
             })?;
             // HACK: The condition "dummy span + group with empty delimiter" represents an AST
             // fragment approximately converted into a token stream. This may happen, for
@@ -426,7 +448,7 @@ impl server::TokenStreamIter for Rustc {
     }
 }
 
-impl server::Group for Rustc {
+impl server::Group for Rustc<'_> {
     fn new(&mut self, delimiter: Delimiter, stream: Self::TokenStream) -> Self::Group {
         Group {
             delimiter,
@@ -454,7 +476,7 @@ impl server::Group for Rustc {
     }
 }
 
-impl server::Punct for Rustc {
+impl server::Punct for Rustc<'_> {
     fn new(&mut self, ch: char, spacing: Spacing) -> Self::Punct {
         Punct {
             ch,
@@ -480,7 +502,7 @@ impl server::Punct for Rustc {
     }
 }
 
-impl server::Ident for Rustc {
+impl server::Ident for Rustc<'_> {
     fn new(&mut self, string: &str, span: Self::Span, is_raw: bool) -> Self::Ident {
         let sym = Symbol::intern(string);
         if is_raw
@@ -499,7 +521,7 @@ impl server::Ident for Rustc {
     }
 }
 
-impl server::Literal for Rustc {
+impl server::Literal for Rustc<'_> {
     // FIXME(eddyb) `Literal` should not expose internal `Debug` impls.
     fn debug(&mut self, literal: &Self::Literal) -> String {
         format!("{:?}", literal)
@@ -616,7 +638,7 @@ impl server::Literal for Rustc {
     }
 }
 
-impl server::SourceFile for Rustc {
+impl<'a> server::SourceFile for Rustc<'a> {
     fn eq(&mut self, file1: &Self::SourceFile, file2: &Self::SourceFile) -> bool {
         Lrc::ptr_eq(file1, file2)
     }
@@ -634,7 +656,7 @@ impl server::SourceFile for Rustc {
     }
 }
 
-impl server::MultiSpan for Rustc {
+impl server::MultiSpan for Rustc<'_> {
     fn new(&mut self) -> Self::MultiSpan {
         vec![]
     }
@@ -643,7 +665,7 @@ impl server::MultiSpan for Rustc {
     }
 }
 
-impl server::Diagnostic for Rustc {
+impl server::Diagnostic for Rustc<'_> {
     fn new(&mut self, level: Level, msg: &str, spans: Self::MultiSpan) -> Self::Diagnostic {
         let mut diag = Diagnostic::new(level.to_internal(), msg);
         diag.set_span(MultiSpan::from_spans(spans));
@@ -659,24 +681,22 @@ impl server::Diagnostic for Rustc {
         diag.sub(level.to_internal(), msg, MultiSpan::from_spans(spans), None);
     }
     fn emit(&mut self, diag: Self::Diagnostic) {
-        ::__internal::with_sess(move |sess, _| {
-            DiagnosticBuilder::new_diagnostic(&sess.span_diagnostic, diag).emit()
-        });
+        DiagnosticBuilder::new_diagnostic(&self.sess.span_diagnostic, diag).emit()
     }
 }
 
-impl server::Span for Rustc {
+impl server::Span for Rustc<'_> {
     fn debug(&mut self, span: Self::Span) -> String {
         format!("{:?} bytes({}..{})", span.ctxt(), span.lo().0, span.hi().0)
     }
     fn def_site(&mut self) -> Self::Span {
-        ::__internal::with_sess(|_, data| data.def_site)
+        self.def_site
     }
     fn call_site(&mut self) -> Self::Span {
-        ::__internal::with_sess(|_, data| data.call_site)
+        self.call_site
     }
     fn source_file(&mut self, span: Self::Span) -> Self::SourceFile {
-        ::__internal::lookup_char_pos(span.lo()).file
+        self.sess.source_map().lookup_char_pos(span.lo()).file
     }
     fn parent(&mut self, span: Self::Span) -> Option<Self::Span> {
         span.ctxt().outer().expn_info().map(|i| i.call_site)
@@ -685,22 +705,22 @@ impl server::Span for Rustc {
         span.source_callsite()
     }
     fn start(&mut self, span: Self::Span) -> LineColumn {
-        let loc = ::__internal::lookup_char_pos(span.lo());
+        let loc = self.sess.source_map().lookup_char_pos(span.lo());
         LineColumn {
             line: loc.line,
             column: loc.col.to_usize(),
         }
     }
     fn end(&mut self, span: Self::Span) -> LineColumn {
-        let loc = ::__internal::lookup_char_pos(span.hi());
+        let loc = self.sess.source_map().lookup_char_pos(span.hi());
         LineColumn {
             line: loc.line,
             column: loc.col.to_usize(),
         }
     }
     fn join(&mut self, first: Self::Span, second: Self::Span) -> Option<Self::Span> {
-        let self_loc = ::__internal::lookup_char_pos(first.lo());
-        let other_loc = ::__internal::lookup_char_pos(second.lo());
+        let self_loc = self.sess.source_map().lookup_char_pos(first.lo());
+        let other_loc = self.sess.source_map().lookup_char_pos(second.lo());
 
         if self_loc.file.name != other_loc.file.name {
             return None;
diff --git a/src/libsyntax_ext/deriving/custom.rs b/src/libsyntax_ext/deriving/custom.rs
@@ -77,12 +77,9 @@ impl MultiItemModifier for ProcMacroDerive {
         let item = ecx.resolver.eliminate_crate_var(item);
         let token = Token::interpolated(token::NtItem(item));
         let input = tokenstream::TokenTree::Token(DUMMY_SP, token).into();
-        let server = ::proc_macro::rustc::Rustc;
-        let res = ::proc_macro::__internal::set_sess(ecx, || {
-            self.client.run(&EXEC_STRATEGY, server, input)
-        });
 
-        let stream = match res {
+        let server = ::proc_macro::rustc::Rustc::new(ecx);
+        let stream = match self.client.run(&EXEC_STRATEGY, server, input) {
             Ok(stream) => stream,
             Err(e) => {
                 let msg = "proc-macro derive panicked";
@@ -103,13 +100,14 @@ impl MultiItemModifier for ProcMacroDerive {
         let mut items = vec![];
 
         loop {
-            match parser.parse_item().map_err(::proc_macro::__internal::parse_to_lex_err) {
+            match parser.parse_item() {
                 Ok(None) => break,
                 Ok(Some(item)) => {
                     items.push(Annotatable::Item(item))
                 }
-                Err(_) => {
+                Err(mut err) => {
                     // FIXME: handle this better
+                    err.cancel();
                     ecx.struct_span_fatal(span, msg).emit();
                     FatalError.raise();
                 }
diff --git a/src/libsyntax_ext/proc_macro_impl.rs b/src/libsyntax_ext/proc_macro_impl.rs
