Remove proc_macro::SourceFile::is_real().

Author: m-ou-se

Diff for: compiler/rustc_expand/src/proc_macro_server.rs

@@ -689,10 +689,6 @@ impl server::SourceFile for Rustc<'_, '_> {
             _ => file.name.prefer_local().to_string(),
         }
     }
-
-    fn is_real(&mut self, file: &Self::SourceFile) -> bool {
-        file.is_real_file()
-    }
 }
 
 impl server::Span for Rustc<'_, '_> {

Diff for: library/proc_macro/src/bridge/mod.rs

@@ -86,7 +86,6 @@ macro_rules! with_api {
                 fn clone($self: &$S::SourceFile) -> $S::SourceFile;
                 fn eq($self: &$S::SourceFile, other: &$S::SourceFile) -> bool;
                 fn path($self: &$S::SourceFile) -> String;
-                fn is_real($self: &$S::SourceFile) -> bool;
             },
             Span {
                 fn debug($self: $S::Span) -> String;

Diff for: library/proc_macro/src/lib.rs

@@ -623,36 +623,19 @@ impl SourceFile {
     /// Gets the path to this source file.
     ///
     /// ### Note
-    /// If the code span associated with this `SourceFile` was generated by an external macro, this
-    /// macro, this might not be an actual path on the filesystem. Use [`is_real`] to check.
     ///
-    /// Also note that even if `is_real` returns `true`, if `--remap-path-prefix` was passed on
+    /// If `--remap-path-prefix` was passed on
     /// the command line, the path as given might not actually be valid.
-    ///
-    /// [`is_real`]: Self::is_real
     #[unstable(feature = "proc_macro_span", issue = "54725")]
     pub fn path(&self) -> PathBuf {
         PathBuf::from(self.0.path())
     }
-
-    /// Returns `true` if this source file is a real source file, and not generated by an external
-    /// macro's expansion.
-    #[unstable(feature = "proc_macro_span", issue = "54725")]
-    pub fn is_real(&self) -> bool {
-        // 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.0.is_real()
-    }
 }
 
 #[unstable(feature = "proc_macro_span", issue = "54725")]
 impl fmt::Debug for SourceFile {
     fn fmt(&self, f: &mut fmt::Formatter<'_>) -> fmt::Result {
-        f.debug_struct("SourceFile")
-            .field("path", &self.path())
-            .field("is_real", &self.is_real())
-            .finish()
+        f.debug_struct("SourceFile").field("path", &self.path()).finish()
     }
 }
 

Diff for: tests/ui/proc-macro/auxiliary/span-api-tests.rs

@@ -10,21 +10,11 @@ pub fn reemit(input: TokenStream) -> TokenStream {
     input.to_string().parse().unwrap()
 }
 
-#[proc_macro]
-pub fn assert_fake_source_file(input: TokenStream) -> TokenStream {
-    for tk in input {
-        let source_file = tk.span().source_file();
-        assert!(!source_file.is_real(), "Source file is real: {:?}", source_file);
-    }
-
-    "".parse().unwrap()
-}
-
 #[proc_macro]
 pub fn assert_source_file(input: TokenStream) -> TokenStream {
     for tk in input {
         let source_file = tk.span().source_file();
-        assert!(source_file.is_real(), "Source file is not real: {:?}", source_file);
+        assert!(!source_file.as_os_str().is_empty(), "No source file for span: {:?}", tk.span());
     }
 
     "".parse().unwrap()

Diff for: tests/ui/proc-macro/span-api-tests.rs

@@ -8,8 +8,6 @@ extern crate span_test_macros;
 
 extern crate span_api_tests;
 
-// FIXME(69775): Investigate `assert_fake_source_file`.
-
 use span_api_tests::{reemit, assert_source_file, macro_stringify};
 
 macro_rules! say_hello {