proc_macro: move SourceFile to the bridge.

Author: eddyb

src/libproc_macro/bridge.rs

@@ -21,6 +21,7 @@
 
 use std::cell::Cell;
 use std::fmt;
+use std::path::PathBuf;
 use std::ptr::NonNull;
 
 use self::storage::{FromConcrete, ToConcrete};
@@ -195,6 +196,8 @@ storage_concrete_passthrough! {
     [] ::Span,
     [] ::Delimiter,
     [] ::LexError,
+
+    [] PathBuf,
     // NOTE(eddyb) this will need some `extern "C" fn write`.
     ['a, 'b] &'a mut fmt::Formatter<'b>,
     [] fmt::Error
@@ -243,6 +246,17 @@ macro_rules! each_frontend_method {
         });
         $meth!(fn token_cursor_next(&self, cursor: &mut Self::TokenCursor)
                                     -> Option<Self::TokenStream>;);
+
+        $meth!(fn source_file_cleanup(&self, _file: Self::SourceFile) -> () {});
+        $meth!(fn source_file_clone(&self, file: &Self::SourceFile) -> Self::SourceFile {
+            file.clone()
+        });
+        $meth!(fn source_file_eq(&self, file1: &Self::SourceFile,
+                                 file2: &Self::SourceFile) -> bool;);
+        $meth!(fn source_file_path(&self, file: &Self::SourceFile) -> PathBuf;);
+        $meth!(fn source_file_is_real(&self, file: &Self::SourceFile) -> bool;);
+
+        $meth!(fn span_source_file(&self, span: ::Span) -> Self::SourceFile;);
     }
 }
 
@@ -253,6 +267,7 @@ pub trait FrontendInterface {
     type TokenStream: 'static + Clone + fmt::Debug + fmt::Display;
     type TokenStreamBuilder: 'static;
     type TokenCursor: 'static + Clone;
+    type SourceFile: 'static + Clone;
     each_frontend_method!(define_frontend_trait_method);
 }
 
@@ -310,6 +325,9 @@ define_boxed! {
     },
     TokenCursor {
         cleanup: token_cursor_cleanup
+    },
+    SourceFile {
+        cleanup: source_file_cleanup
     }
 }
 
@@ -337,6 +355,12 @@ impl Clone for TokenCursor {
     }
 }
 
+impl Clone for SourceFile {
+    fn clone(&self) -> Self {
+        Frontend.source_file_clone(self)
+    }
+}
+
 pub(crate) struct Frontend;
 
 macro_rules! define_frontend_current_method {
@@ -351,6 +375,7 @@ impl FrontendInterface for Frontend {
     type TokenStream = TokenStream;
     type TokenStreamBuilder = TokenStreamBuilder;
     type TokenCursor = TokenCursor;
+    type SourceFile = SourceFile;
     each_frontend_method!(define_frontend_current_method);
 }
 
@@ -359,6 +384,7 @@ type CurrentFrontend<'a> = FrontendInterface<
     TokenStream = TokenStream,
     TokenStreamBuilder = TokenStreamBuilder,
     TokenCursor = TokenCursor,
+    SourceFile = SourceFile,
 > + 'a;
 
 // Emulate scoped_thread_local!() here essentially
@@ -421,6 +447,7 @@ fn erase_concrete_frontend<F, G, R>(ng: extern "C" fn() -> generation::Generatio
         type TokenStream = TokenStream;
         type TokenStreamBuilder = TokenStreamBuilder;
         type TokenCursor = TokenCursor;
+        type SourceFile = SourceFile;
         each_frontend_method!(define_frontend_erase_concrete_method);
     }
 

src/libproc_macro/lib.rs

@@ -65,13 +65,12 @@ pub use diagnostic::{Diagnostic, Level};
 
 use std::{ascii, fmt, iter};
 use std::path::PathBuf;
-use rustc_data_structures::sync::Lrc;
 use std::str::FromStr;
 
 use syntax::parse::token;
 use syntax::symbol::Symbol;
 use syntax_pos::DUMMY_SP;
-use syntax_pos::{FileMap, Pos, SyntaxContext, FileName};
+use syntax_pos::{Pos, SyntaxContext};
 
 /// The main type provided by this crate, representing an abstract stream of
 /// tokens.
@@ -224,9 +223,7 @@ impl Span {
     /// The original source file into which this span points.
     #[unstable(feature = "proc_macro", issue = "38356")]
     pub fn source_file(&self) -> SourceFile {
-        SourceFile {
-            filemap: __internal::lookup_char_pos(self.0.lo()).file,
-        }
+        SourceFile(Frontend.span_source_file(*self))
     }
 
     /// The `Span` for the tokens in the previous macro expansion from which
@@ -313,14 +310,7 @@ pub struct LineColumn {
 /// The source file of a given `Span`.
 #[unstable(feature = "proc_macro", issue = "38356")]
 #[derive(Clone)]
-pub struct SourceFile {
-    filemap: Lrc<FileMap>,
-}
-
-#[unstable(feature = "proc_macro", issue = "38356")]
-impl !Send for SourceFile {}
-#[unstable(feature = "proc_macro", issue = "38356")]
-impl !Sync for SourceFile {}
+pub struct SourceFile(bridge::SourceFile);
 
 impl SourceFile {
     /// Get the path to this source file.
@@ -335,10 +325,7 @@ impl SourceFile {
     /// [`is_real`]: #method.is_real
     #[unstable(feature = "proc_macro", issue = "38356")]
     pub fn path(&self) -> PathBuf {
-        match self.filemap.name {
-            FileName::Real(ref path) => path.clone(),
-            _ => PathBuf::from(self.filemap.name.to_string())
-        }
+        Frontend.source_file_path(&self.0)
     }
 
     /// Returns `true` if this source file is a real source file, and not generated by an external
@@ -348,7 +335,7 @@ impl SourceFile {
         // This is a hack until intercrate spans are implemented and we can have real source files
         // for spans generated in external macros.
         // https://github.com/rust-lang/rust/pull/43604#issuecomment-333334368
-        self.filemap.is_real_file()
+        Frontend.source_file_is_real(&self.0)
     }
 }
 
@@ -366,7 +353,7 @@ impl fmt::Debug for SourceFile {
 #[unstable(feature = "proc_macro", issue = "38356")]
 impl PartialEq for SourceFile {
     fn eq(&self, other: &Self) -> bool {
-        Lrc::ptr_eq(&self.filemap, &other.filemap)
+        Frontend.source_file_eq(&self.0, &other.0)
     }
 }
 

src/libproc_macro/rustc.rs

@@ -10,7 +10,9 @@
 
 use {__internal, Delimiter, Spacing, Span, Term, TokenNode, TokenTree};
 
-use syntax_pos::{self, SyntaxContext, FileName};
+use rustc_data_structures::sync::Lrc;
+use std::path::PathBuf;
+use syntax_pos::{self, SyntaxContext, FileMap, FileName};
 use syntax_pos::hygiene::Mark;
 use syntax::ast;
 use syntax::ext::base::{ExtCtxt, ProcMacro};
@@ -58,7 +60,7 @@ impl ::bridge::FrontendInterface for Rustc {
     type TokenStream = tokenstream::TokenStream;
     type TokenStreamBuilder = tokenstream::TokenStreamBuilder;
     type TokenCursor = tokenstream::Cursor;
-
+    type SourceFile = Lrc<FileMap>;
 
     fn token_stream_empty(&self) -> Self::TokenStream {
         tokenstream::TokenStream::empty()
@@ -279,4 +281,21 @@ impl ::bridge::FrontendInterface for Rustc {
         }
         None
     }
+
+    fn source_file_eq(&self, file1: &Self::SourceFile, file2: &Self::SourceFile) -> bool {
+        Lrc::ptr_eq(file1, file2)
+    }
+    fn source_file_path(&self, file: &Self::SourceFile) -> PathBuf {
+        match file.name {
+            FileName::Real(ref path) => path.clone(),
+            _ => PathBuf::from(file.name.to_string())
+        }
+    }
+    fn source_file_is_real(&self, file: &Self::SourceFile) -> bool {
+        file.is_real_file()
+    }
+
+    fn span_source_file(&self, span: ::Span) -> Self::SourceFile {
+        ::__internal::lookup_char_pos(span.0.lo()).file
+    }
 }