Make local_crate_source_file return a RealFileName

so it can be remapped (or not) by callers

compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs

@@ -99,9 +99,16 @@ impl DebugContext {
                 FileNameDisplayPreference::Local
             })
             .into_owned();
+
         let (name, file_info) = match tcx.sess.local_crate_source_file() {
             Some(path) => {
-                let name = path.to_string_lossy().into_owned();
+                let name = path
+                    .to_string_lossy(if should_remap_filepaths {
+                        FileNameDisplayPreference::Remapped
+                    } else {
+                        FileNameDisplayPreference::Local
+                    })
+                    .into_owned();
                 (name, None)
             }
             None => (tcx.crate_name(LOCAL_CRATE).to_string(), None),

compiler/rustc_codegen_llvm/src/debuginfo/metadata.rs

@@ -838,9 +838,11 @@ pub fn build_compile_unit_di_node<'ll, 'tcx>(
     codegen_unit_name: &str,
     debug_context: &CodegenUnitDebugContext<'ll, 'tcx>,
 ) -> &'ll DIDescriptor {
+    use rustc_session::{config::RemapPathScopeComponents, RemapFileNameExt};
     let mut name_in_debuginfo = tcx
         .sess
         .local_crate_source_file()
+        .map(|src| src.for_scope(&tcx.sess, RemapPathScopeComponents::DEBUGINFO).to_path_buf())
         .unwrap_or_else(|| PathBuf::from(tcx.crate_name(LOCAL_CRATE).as_str()));
 
     // To avoid breaking split DWARF, we need to ensure that each codegen unit
@@ -868,7 +870,6 @@ pub fn build_compile_unit_di_node<'ll, 'tcx>(
     // FIXME(#41252) Remove "clang LLVM" if we can get GDB and LLVM to play nice.
     let producer = format!("clang LLVM ({rustc_producer})");
 
-    use rustc_session::{config::RemapPathScopeComponents, RemapFileNameExt};
     let name_in_debuginfo = name_in_debuginfo.to_string_lossy();
     let work_dir = tcx
         .sess

compiler/rustc_passes/src/entry.rs

@@ -7,6 +7,7 @@ use rustc_hir::{ItemId, Node, CRATE_HIR_ID};
 use rustc_middle::query::Providers;
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::{sigpipe, CrateType, EntryFnType};
+use rustc_session::{config::RemapPathScopeComponents, RemapFileNameExt};
 use rustc_span::symbol::sym;
 use rustc_span::{Span, Symbol};
 
@@ -165,10 +166,14 @@ fn no_main_err(tcx: TyCtxt<'_>, visitor: &EntryContext<'_>) {
 
     // There is no main function.
     let mut has_filename = true;
-    let filename = tcx.sess.local_crate_source_file().unwrap_or_else(|| {
-        has_filename = false;
-        Default::default()
-    });
+    let filename = tcx
+        .sess
+        .local_crate_source_file()
+        .map(|src| src.for_scope(&tcx.sess, RemapPathScopeComponents::DIAGNOSTICS).to_path_buf())
+        .unwrap_or_else(|| {
+            has_filename = false;
+            Default::default()
+        });
     let main_def_opt = tcx.resolutions(()).main_def;
     let code = E0601;
     let add_teach_note = tcx.sess.teach(code);

compiler/rustc_session/src/session.rs

@@ -29,6 +29,7 @@ use rustc_macros::HashStable_Generic;
 pub use rustc_span::def_id::StableCrateId;
 use rustc_span::edition::Edition;
 use rustc_span::source_map::{FileLoader, FilePathMapping, RealFileLoader, SourceMap};
+use rustc_span::RealFileName;
 use rustc_span::{SourceFileHashAlgorithm, Span, Symbol};
 use rustc_target::asm::InlineAsmArch;
 use rustc_target::spec::{CodeModel, PanicStrategy, RelocModel, RelroLevel};
@@ -250,14 +251,9 @@ impl Session {
         self.miri_unleashed_features.lock().push((span, feature_gate));
     }
 
-    pub fn local_crate_source_file(&self) -> Option<PathBuf> {
+    pub fn local_crate_source_file(&self) -> Option<RealFileName> {
         let path = self.io.input.opt_path()?;
-        // FIXME: The remap path scope should probably not be hardcoded.
-        if self.should_prefer_remapped(RemapPathScopeComponents::DEBUGINFO) {
-            Some(self.opts.file_path_mapping().map_prefix(path).0.into_owned())
-        } else {
-            Some(path.to_path_buf())
-        }
+        Some(RealFileName::LocalPath(path.to_path_buf()))
     }
 
     fn check_miri_unleashed_features(&self) -> Option<ErrorGuaranteed> {

src/librustdoc/html/render/mod.rs

@@ -2506,7 +2506,7 @@ fn render_call_locations<W: fmt::Write>(mut w: W, cx: &mut Context<'_>, item: &c
         // Look for the example file in the source map if it exists, otherwise return a dummy span
         let file_span = (|| {
             let source_map = tcx.sess.source_map();
-            let crate_src = tcx.sess.local_crate_source_file()?;
+            let crate_src = tcx.sess.local_crate_source_file()?.into_local_path()?;
             let abs_crate_src = crate_src.canonicalize().ok()?;
             let crate_root = abs_crate_src.parent()?.parent()?;
             let rel_path = path.strip_prefix(crate_root).ok()?;