Auto merge of #149709 - Urgau:overhaul-filenames, r=davidtwco

Overhaul filename handling for cross-compiler consistency

This PR overhauls the way we handle filenames in the compiler and `rmeta` in order to achieve achieve cross-compiler consistency (ie. having the same path no matter if the filename was created in the current compiler session or is coming from `rmeta`).

This is required as some parts of the compiler rely on consistent paths for the soundness of generated code (see #148328).

In order to achieved consistency multiple steps are being taken by this PR:
 - by making `RealFileName` immutable
 - by only having `SourceMap::to_real_filename` create `RealFileName`
   - currently `RealFileName` can be created from any `Path` and are remapped afterwards, which creates consistency issue
 - by also making `RealFileName` holds it's working directory, embeddable name and the remapped scopes
   - this removes the need for a `Session`, to know the current(!) scopes and cwd, which is invalid as they may not be equal to the scopes used when creating the filename

In order for `SourceMap::to_real_filename` to know which scopes to apply `FilePathMapping` now takes the current remapping scopes to apply, which makes `FileNameDisplayPreference` and company useless and are removed.

This PR is split-up in multiple commits (unfortunately not atomic), but should help review the changes.

Unblocks #147611
Fixes #148328

Author: bors

Cargo.lock

@@ -4632,7 +4632,6 @@ dependencies = [
 name = "rustc_session"
 version = "0.0.0"
 dependencies = [
- "bitflags",
  "getopts",
  "libc",
  "rand 0.9.2",
@@ -4659,6 +4658,7 @@ dependencies = [
 name = "rustc_span"
 version = "0.0.0"
 dependencies = [
+ "bitflags",
  "blake3",
  "derive-where",
  "indexmap",

compiler/rustc_borrowck/src/region_infer/dump_mir.rs

@@ -80,7 +80,7 @@ impl<'tcx> RegionInferenceContext<'tcx> {
             let OutlivesConstraint { sup, sub, locations, category, span, .. } = constraint;
             let (name, arg) = match locations {
                 Locations::All(span) => {
-                    ("All", tcx.sess.source_map().span_to_embeddable_string(*span))
+                    ("All", tcx.sess.source_map().span_to_diagnostic_string(*span))
                 }
                 Locations::Single(loc) => ("Single", format!("{loc:?}")),
             };

compiler/rustc_builtin_macros/src/source_util.rs

@@ -68,13 +68,10 @@ pub(crate) fn expand_file(
     let topmost = cx.expansion_cause().unwrap_or(sp);
     let loc = cx.source_map().lookup_char_pos(topmost.lo());
 
-    use rustc_session::RemapFileNameExt;
-    use rustc_session::config::RemapPathScopeComponents;
+    use rustc_span::RemapPathScopeComponents;
     ExpandResult::Ready(MacEager::expr(cx.expr_str(
         topmost,
-        Symbol::intern(
-            &loc.file.name.for_scope(cx.sess, RemapPathScopeComponents::MACRO).to_string_lossy(),
-        ),
+        Symbol::intern(&loc.file.name.display(RemapPathScopeComponents::MACRO).to_string_lossy()),
     )))
 }
 

compiler/rustc_builtin_macros/src/test.rs

@@ -11,7 +11,7 @@ use rustc_errors::{Applicability, Diag, Level};
 use rustc_expand::base::*;
 use rustc_hir::Attribute;
 use rustc_hir::attrs::AttributeKind;
-use rustc_span::{ErrorGuaranteed, FileNameDisplayPreference, Ident, Span, Symbol, sym};
+use rustc_span::{ErrorGuaranteed, Ident, RemapPathScopeComponents, Span, Symbol, sym};
 use thin_vec::{ThinVec, thin_vec};
 use tracing::debug;
 
@@ -445,7 +445,7 @@ fn get_location_info(cx: &ExtCtxt<'_>, fn_: &ast::Fn) -> (Symbol, usize, usize,
         cx.sess.source_map().span_to_location_info(span);
 
     let file_name = match source_file {
-        Some(sf) => sf.name.display(FileNameDisplayPreference::Remapped).to_string(),
+        Some(sf) => sf.name.display(RemapPathScopeComponents::MACRO).to_string(),
         None => "no-location".to_string(),
     };
 

compiler/rustc_codegen_cranelift/src/debuginfo/line_info.rs

@@ -6,7 +6,10 @@ use std::path::{Component, Path};
 use cranelift_codegen::MachSrcLoc;
 use cranelift_codegen::binemit::CodeOffset;
 use gimli::write::{FileId, FileInfo, LineProgram, LineString, LineStringTable};
-use rustc_span::{FileName, Pos, SourceFile, SourceFileAndLine, SourceFileHashAlgorithm, hygiene};
+use rustc_span::{
+    FileName, Pos, RemapPathScopeComponents, SourceFile, SourceFileAndLine,
+    SourceFileHashAlgorithm, hygiene,
+};
 
 use crate::debuginfo::FunctionDebugContext;
 use crate::debuginfo::emit::address_for_func;
@@ -95,7 +98,7 @@ impl DebugContext {
             match &source_file.name {
                 FileName::Real(path) => {
                     let (dir_path, file_name) =
-                        split_path_dir_and_file(path.to_path(self.filename_display_preference));
+                        split_path_dir_and_file(path.path(RemapPathScopeComponents::DEBUGINFO));
                     let dir_name = osstr_as_utf8_bytes(dir_path.as_os_str());
                     let file_name = osstr_as_utf8_bytes(file_name);
 

compiler/rustc_codegen_cranelift/src/debuginfo/mod.rs

@@ -21,7 +21,7 @@ use rustc_hir::def::DefKind;
 use rustc_hir::def_id::DefIdMap;
 use rustc_session::Session;
 use rustc_session::config::DebugInfo;
-use rustc_span::{FileNameDisplayPreference, SourceFileHash, StableSourceFileId};
+use rustc_span::{RemapPathScopeComponents, SourceFileHash, StableSourceFileId};
 use rustc_target::callconv::FnAbi;
 
 pub(crate) use self::emit::{DebugReloc, DebugRelocName};
@@ -44,7 +44,6 @@ pub(crate) struct DebugContext {
     namespace_map: DefIdMap<UnitEntryId>,
     array_size_type: Option<UnitEntryId>,
 
-    filename_display_preference: FileNameDisplayPreference,
     embed_source: bool,
 }
 
@@ -102,18 +101,18 @@ impl DebugContext {
 
         let mut dwarf = DwarfUnit::new(encoding);
 
-        use rustc_session::config::RemapPathScopeComponents;
-
-        let filename_display_preference =
-            tcx.sess.filename_display_preference(RemapPathScopeComponents::DEBUGINFO);
-
         let producer = producer(tcx.sess);
-        let comp_dir =
-            tcx.sess.opts.working_dir.to_string_lossy(filename_display_preference).to_string();
+        let comp_dir = tcx
+            .sess
+            .source_map()
+            .working_dir()
+            .path(RemapPathScopeComponents::DEBUGINFO)
+            .to_string_lossy();
 
         let (name, file_info) = match tcx.sess.local_crate_source_file() {
             Some(path) => {
-                let name = path.to_string_lossy(filename_display_preference).to_string();
+                let name =
+                    path.path(RemapPathScopeComponents::DEBUGINFO).to_string_lossy().into_owned();
                 (name, None)
             }
             None => (tcx.crate_name(LOCAL_CRATE).to_string(), None),
@@ -137,7 +136,7 @@ impl DebugContext {
 
         {
             let name = dwarf.strings.add(format!("{name}/@/{cgu_name}"));
-            let comp_dir = dwarf.strings.add(comp_dir);
+            let comp_dir = dwarf.strings.add(&*comp_dir);
 
             let root = dwarf.unit.root();
             let root = dwarf.unit.get_mut(root);
@@ -180,7 +179,6 @@ impl DebugContext {
             stack_pointer_register,
             namespace_map: DefIdMap::default(),
             array_size_type,
-            filename_display_preference,
             embed_source,
         })
     }

compiler/rustc_codegen_gcc/src/debuginfo.rs

@@ -297,29 +297,11 @@ impl<'gcc, 'tcx> DebugInfoCodegenMethods<'tcx> for CodegenCx<'gcc, 'tcx> {
         let pos = span.lo();
         let DebugLoc { file, line, col } = self.lookup_debug_loc(pos);
         match file.name {
-            rustc_span::FileName::Real(ref name) => match *name {
-                rustc_span::RealFileName::LocalPath(ref name) => {
-                    if let Some(name) = name.to_str() {
-                        self.context.new_location(name, line as i32, col as i32)
-                    } else {
-                        Location::null()
-                    }
-                }
-                rustc_span::RealFileName::Remapped {
-                    ref local_path,
-                    virtual_name: ref _unused,
-                } => {
-                    if let Some(name) = local_path.as_ref() {
-                        if let Some(name) = name.to_str() {
-                            self.context.new_location(name, line as i32, col as i32)
-                        } else {
-                            Location::null()
-                        }
-                    } else {
-                        Location::null()
-                    }
-                }
-            },
+            rustc_span::FileName::Real(ref name) => self.context.new_location(
+                name.path(rustc_span::RemapPathScopeComponents::DEBUGINFO).to_string_lossy(),
+                line as i32,
+                col as i32,
+            ),
             _ => Location::null(),
         }
     }

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -21,10 +21,8 @@ use rustc_errors::{DiagCtxtHandle, Level};
 use rustc_fs_util::{link_or_copy, path_to_c_string};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::Session;
-use rustc_session::config::{
-    self, Lto, OutputType, Passes, RemapPathScopeComponents, SplitDwarfKind, SwitchWithOptPath,
-};
-use rustc_span::{BytePos, InnerSpan, Pos, SpanData, SyntaxContext, sym};
+use rustc_session::config::{self, Lto, OutputType, Passes, SplitDwarfKind, SwitchWithOptPath};
+use rustc_span::{BytePos, InnerSpan, Pos, RemapPathScopeComponents, SpanData, SyntaxContext, sym};
 use rustc_target::spec::{
     Arch, CodeModel, FloatAbi, RelocModel, SanitizerSet, SplitDebuginfo, TlsModel,
 };
@@ -248,6 +246,7 @@ pub(crate) fn target_machine_factory(
         !sess.opts.unstable_opts.use_ctors_section.unwrap_or(sess.target.use_ctors_section);
 
     let path_mapping = sess.source_map().path_mapping().clone();
+    let working_dir = sess.source_map().working_dir().clone();
 
     let use_emulated_tls = matches!(sess.tls_model(), TlsModel::Emulated);
 
@@ -271,9 +270,6 @@ pub(crate) fn target_machine_factory(
         }
     };
 
-    let file_name_display_preference =
-        sess.filename_display_preference(RemapPathScopeComponents::DEBUGINFO);
-
     let use_wasm_eh = wants_wasm_eh(sess);
 
     let prof = SelfProfilerRef::clone(&sess.prof);
@@ -284,8 +280,9 @@ pub(crate) fn target_machine_factory(
         let path_to_cstring_helper = |path: Option<PathBuf>| -> CString {
             let path = path.unwrap_or_default();
             let path = path_mapping
-                .to_real_filename(path)
-                .to_string_lossy(file_name_display_preference)
+                .to_real_filename(&working_dir, path)
+                .path(RemapPathScopeComponents::DEBUGINFO)
+                .to_string_lossy()
                 .into_owned();
             CString::new(path).unwrap()
         };

compiler/rustc_codegen_llvm/src/coverageinfo/mapgen.rs

@@ -7,9 +7,7 @@ use rustc_codegen_ssa::traits::{BaseTypeCodegenMethods, ConstCodegenMethods};
 use rustc_data_structures::fx::FxIndexMap;
 use rustc_index::IndexVec;
 use rustc_middle::ty::TyCtxt;
-use rustc_session::RemapFileNameExt;
-use rustc_session::config::RemapPathScopeComponents;
-use rustc_span::{SourceFile, StableSourceFileId};
+use rustc_span::{RemapPathScopeComponents, SourceFile, StableSourceFileId};
 use tracing::debug;
 
 use crate::common::CodegenCx;
@@ -127,10 +125,7 @@ impl GlobalFileTable {
 
         for file in all_files {
             raw_file_table.entry(file.stable_id).or_insert_with(|| {
-                file.name
-                    .for_scope(tcx.sess, RemapPathScopeComponents::COVERAGE)
-                    .to_string_lossy()
-                    .into_owned()
+                file.name.display(RemapPathScopeComponents::COVERAGE).to_string_lossy().into_owned()
             });
         }
 
@@ -145,9 +140,10 @@ impl GlobalFileTable {
         // resolve any other entries that are stored as relative paths.
         let base_dir = tcx
             .sess
-            .opts
-            .working_dir
-            .for_scope(tcx.sess, RemapPathScopeComponents::COVERAGE)
+            .psess
+            .source_map()
+            .working_dir()
+            .path(RemapPathScopeComponents::COVERAGE)
             .to_string_lossy();
         table.push(base_dir.as_ref());