Auto merge of #106810 - oli-obk:resolver_reverse_plumbing, r=petrochenkov

Various cleanups around pre-TyCtxt queries and functions

part of #105462

based on https://github.com/rust-lang/rust/pull/106776 (everything starting at [0e2b39f](https://github.com/rust-lang/rust/pull/106810/commits/0e2b39fd1ffde51b50d45ccbe41de52b85136b8b) is new in this PR)

r? `@petrochenkov`

I think this should be most of the uncontroversial part of #105462.

compiler/rustc_session/src/config.rs

@@ -591,6 +591,24 @@ impl Input {
             Input::Str { ref name, .. } => name.clone(),
         }
     }
+
+    pub fn opt_path(&self) -> Option<&Path> {
+        match self {
+            Input::File(file) => Some(file),
+            Input::Str { name, .. } => match name {
+                FileName::Real(real) => real.local_path(),
+                FileName::QuoteExpansion(_) => None,
+                FileName::Anon(_) => None,
+                FileName::MacroExpansion(_) => None,
+                FileName::ProcMacroSourceCode(_) => None,
+                FileName::CfgSpec(_) => None,
+                FileName::CliCrateAttr(_) => None,
+                FileName::Custom(_) => None,
+                FileName::DocTest(path, _) => Some(path),
+                FileName::InlineAsm(_) => None,
+            },
+        }
+    }
 }
 
 #[derive(Clone, Hash, Debug, HashStable_Generic)]
@@ -2496,12 +2514,12 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
         early_error(error_format, &format!("Current directory is invalid: {e}"));
     });
 
-    let (path, remapped) =
-        FilePathMapping::new(remap_path_prefix.clone()).map_prefix(working_dir.clone());
+    let remap = FilePathMapping::new(remap_path_prefix.clone());
+    let (path, remapped) = remap.map_prefix(&working_dir);
     let working_dir = if remapped {
-        RealFileName::Remapped { local_path: Some(working_dir), virtual_name: path }
+        RealFileName::Remapped { virtual_name: path.into_owned(), local_path: Some(working_dir) }
     } else {
-        RealFileName::LocalPath(path)
+        RealFileName::LocalPath(path.into_owned())
     };
 
     Options {

compiler/rustc_session/src/output.rs

@@ -45,7 +45,7 @@ fn is_writeable(p: &Path) -> bool {
     }
 }
 
-pub fn find_crate_name(sess: &Session, attrs: &[ast::Attribute], input: &Input) -> Symbol {
+pub fn find_crate_name(sess: &Session, attrs: &[ast::Attribute]) -> Symbol {
     let validate = |s: Symbol, span: Option<Span>| {
         validate_crate_name(sess, s, span);
         s
@@ -71,7 +71,7 @@ pub fn find_crate_name(sess: &Session, attrs: &[ast::Attribute], input: &Input)
     if let Some((attr, s)) = attr_crate_name {
         return validate(s, Some(attr.span));
     }
-    if let Input::File(ref path) = *input {
+    if let Input::File(ref path) = sess.io.input {
         if let Some(s) = path.file_stem().and_then(|s| s.to_str()) {
             if s.starts_with('-') {
                 sess.emit_err(CrateNameInvalid { s });

compiler/rustc_session/src/session.rs

@@ -1,6 +1,7 @@
 use crate::cgu_reuse_tracker::CguReuseTracker;
 use crate::code_stats::CodeStats;
 pub use crate::code_stats::{DataTypeKind, FieldInfo, SizeKind, VariantInfo};
+use crate::config::Input;
 use crate::config::{self, CrateType, InstrumentCoverage, OptLevel, OutputType, SwitchWithOptPath};
 use crate::errors::{
     BranchProtectionRequiresAArch64, CannotEnableCrtStaticLinux, CannotMixAndMatchSanitizers,
@@ -137,6 +138,13 @@ pub struct Limits {
     pub const_eval_limit: Limit,
 }
 
+pub struct CompilerIO {
+    pub input: Input,
+    pub output_dir: Option<PathBuf>,
+    pub output_file: Option<PathBuf>,
+    pub temps_dir: Option<PathBuf>,
+}
+
 /// Represents the data associated with a compilation
 /// session for a single crate.
 pub struct Session {
@@ -147,9 +155,8 @@ pub struct Session {
     pub target_tlib_path: Lrc<SearchPath>,
     pub parse_sess: ParseSess,
     pub sysroot: PathBuf,
-    /// The name of the root source file of the crate, in the local file system.
-    /// `None` means that there is no source file.
-    pub local_crate_source_file: Option<PathBuf>,
+    /// Input, input file path and output file path to this compilation process.
+    pub io: CompilerIO,
 
     crate_types: OnceCell<Vec<CrateType>>,
     /// The `stable_crate_id` is constructed out of the crate name and all the
@@ -228,6 +235,11 @@ impl Session {
         self.miri_unleashed_features.lock().push((span, feature_gate));
     }
 
+    pub fn local_crate_source_file(&self) -> Option<PathBuf> {
+        let path = self.io.input.opt_path()?;
+        Some(self.opts.file_path_mapping().map_prefix(path).0.into_owned())
+    }
+
     fn check_miri_unleashed_features(&self) {
         let unleashed_features = self.miri_unleashed_features.lock();
         if !unleashed_features.is_empty() {
@@ -1298,7 +1310,7 @@ fn default_emitter(
 #[allow(rustc::bad_opt_access)]
 pub fn build_session(
     sopts: config::Options,
-    local_crate_source_file: Option<PathBuf>,
+    io: CompilerIO,
     bundle: Option<Lrc<rustc_errors::FluentBundle>>,
     registry: rustc_errors::registry::Registry,
     driver_lint_caps: FxHashMap<lint::LintId, lint::Level>,
@@ -1391,11 +1403,6 @@ pub fn build_session(
         Lrc::new(SearchPath::from_sysroot_and_triple(&sysroot, target_triple))
     };
 
-    let file_path_mapping = sopts.file_path_mapping();
-
-    let local_crate_source_file =
-        local_crate_source_file.map(|path| file_path_mapping.map_prefix(path).0);
-
     let optimization_fuel = Lock::new(OptimizationFuel {
         remaining: sopts.unstable_opts.fuel.as_ref().map_or(0, |&(_, i)| i),
         out_of_fuel: false,
@@ -1427,7 +1434,7 @@ pub fn build_session(
         target_tlib_path,
         parse_sess,
         sysroot,
-        local_crate_source_file,
+        io,
         crate_types: OnceCell::new(),
         stable_crate_id: OnceCell::new(),
         features: OnceCell::new(),