Make opts.maybe_sysroot non-optional

build_session_options always uses materialize_sysroot anyway.

compiler/rustc_error_messages/src/lib.rs

@@ -107,7 +107,7 @@ impl From<Vec<FluentError>> for TranslationBundleError {
 /// (overriding any conflicting messages).
 #[instrument(level = "trace")]
 pub fn fluent_bundle(
-    mut user_provided_sysroot: Option<PathBuf>,
+    mut user_provided_sysroot: PathBuf,
     mut sysroot_candidates: Vec<PathBuf>,
     requested_locale: Option<LanguageIdentifier>,
     additional_ftl_path: Option<&Path>,
@@ -142,7 +142,9 @@ pub fn fluent_bundle(
     // If the user requests the default locale then don't try to load anything.
     if let Some(requested_locale) = requested_locale {
         let mut found_resources = false;
-        for sysroot in user_provided_sysroot.iter_mut().chain(sysroot_candidates.iter_mut()) {
+        for sysroot in
+            Some(&mut user_provided_sysroot).into_iter().chain(sysroot_candidates.iter_mut())
+        {
             sysroot.push("share");
             sysroot.push("locale");
             sysroot.push(requested_locale.to_string());

compiler/rustc_interface/src/interface.rs

@@ -18,7 +18,7 @@ use rustc_parse::parser::attr::AllowLeadingUnsafe;
 use rustc_query_impl::QueryCtxt;
 use rustc_query_system::query::print_query_stack;
 use rustc_session::config::{self, Cfg, CheckCfg, ExpectedValues, Input, OutFileName};
-use rustc_session::filesearch::{self, sysroot_candidates};
+use rustc_session::filesearch::sysroot_candidates;
 use rustc_session::parse::ParseSess;
 use rustc_session::{CompilerIO, EarlyDiagCtxt, Session, lint};
 use rustc_span::source_map::{FileLoader, RealFileLoader, SourceMapInputs};
@@ -390,7 +390,7 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
 
     crate::callbacks::setup_callbacks();
 
-    let sysroot = filesearch::materialize_sysroot(config.opts.maybe_sysroot.clone());
+    let sysroot = config.opts.sysroot.clone();
     let target = config::build_target_config(&early_dcx, &config.opts.target_triple, &sysroot);
     let file_loader = config.file_loader.unwrap_or_else(|| Box::new(RealFileLoader));
     let path_mapping = config.opts.file_path_mapping();
@@ -424,7 +424,7 @@ pub fn run_compiler<R: Send>(config: Config, f: impl FnOnce(&Compiler) -> R + Se
             let temps_dir = config.opts.unstable_opts.temps_dir.as_deref().map(PathBuf::from);
 
             let bundle = match rustc_errors::fluent_bundle(
-                config.opts.maybe_sysroot.clone(),
+                config.opts.sysroot.clone(),
                 sysroot_candidates().to_vec(),
                 config.opts.unstable_opts.translate_lang.clone(),
                 config.opts.unstable_opts.translate_additional_ftl.as_deref(),

compiler/rustc_interface/src/tests.rs

@@ -21,7 +21,7 @@ use rustc_session::config::{
 use rustc_session::lint::Level;
 use rustc_session::search_paths::SearchPath;
 use rustc_session::utils::{CanonicalizedPath, NativeLib, NativeLibKind};
-use rustc_session::{CompilerIO, EarlyDiagCtxt, Session, build_session, filesearch, getopts};
+use rustc_session::{CompilerIO, EarlyDiagCtxt, Session, build_session, getopts};
 use rustc_span::edition::{DEFAULT_EDITION, Edition};
 use rustc_span::source_map::{RealFileLoader, SourceMapInputs};
 use rustc_span::{FileName, SourceFileHashAlgorithm, sym};
@@ -41,7 +41,7 @@ where
 
     let matches = optgroups().parse(args).unwrap();
     let sessopts = build_session_options(&mut early_dcx, &matches);
-    let sysroot = filesearch::materialize_sysroot(sessopts.maybe_sysroot.clone());
+    let sysroot = sessopts.sysroot.clone();
     let target =
         rustc_session::config::build_target_config(&early_dcx, &sessopts.target_triple, &sysroot);
     let hash_kind = sessopts.unstable_opts.src_hash_algorithm(&target);

compiler/rustc_session/src/config.rs

@@ -1214,7 +1214,7 @@ impl Default for Options {
             describe_lints: false,
             output_types: OutputTypes(BTreeMap::new()),
             search_paths: vec![],
-            maybe_sysroot: None,
+            sysroot: filesearch::materialize_sysroot(None),
             target_triple: TargetTuple::from_tuple(host_tuple()),
             test: false,
             incremental: None,
@@ -2618,7 +2618,7 @@ pub fn build_session_options(early_dcx: &mut EarlyDiagCtxt, matches: &getopts::M
         describe_lints,
         output_types,
         search_paths,
-        maybe_sysroot: Some(sysroot),
+        sysroot,
         target_triple,
         test,
         incremental,

compiler/rustc_session/src/options.rs

@@ -333,7 +333,7 @@ top_level_options!(
         output_types: OutputTypes [TRACKED],
         search_paths: Vec<SearchPath> [UNTRACKED],
         libs: Vec<NativeLib> [TRACKED],
-        maybe_sysroot: Option<PathBuf> [UNTRACKED],
+        sysroot: PathBuf [UNTRACKED],
 
         target_triple: TargetTuple [TRACKED],
 

src/librustdoc/config.rs

@@ -103,6 +103,8 @@ pub(crate) struct Options {
     /// compiling doctests from the crate.
     pub(crate) edition: Edition,
     /// The path to the sysroot. Used during the compilation process.
+    pub(crate) sysroot: PathBuf,
+    /// Has the same value as `sysroot` except is `None` when the user didn't pass `---sysroot`.
     pub(crate) maybe_sysroot: Option<PathBuf>,
     /// Lint information passed over the command-line.
     pub(crate) lint_opts: Vec<(String, Level)>,
@@ -202,6 +204,7 @@ impl fmt::Debug for Options {
             .field("unstable_options", &"...")
             .field("target", &self.target)
             .field("edition", &self.edition)
+            .field("sysroot", &self.sysroot)
             .field("maybe_sysroot", &self.maybe_sysroot)
             .field("lint_opts", &self.lint_opts)
             .field("describe_lints", &self.describe_lints)
@@ -834,6 +837,7 @@ impl Options {
             unstable_opts_strs,
             target,
             edition,
+            sysroot,
             maybe_sysroot,
             lint_opts,
             describe_lints,

src/librustdoc/core.rs

@@ -210,7 +210,7 @@ pub(crate) fn create_config(
         unstable_opts,
         target,
         edition,
-        maybe_sysroot,
+        sysroot,
         lint_opts,
         describe_lints,
         lint_cap,
@@ -253,7 +253,7 @@ pub(crate) fn create_config(
     let test = scrape_examples_options.map(|opts| opts.scrape_tests).unwrap_or(false);
     // plays with error output here!
     let sessopts = config::Options {
-        maybe_sysroot,
+        sysroot,
         search_paths: libs,
         crate_types,
         lint_opts,

src/librustdoc/doctest.rs

@@ -158,7 +158,7 @@ pub(crate) fn run(dcx: DiagCtxtHandle<'_>, input: Input, options: RustdocOptions
         if options.proc_macro_crate { vec![CrateType::ProcMacro] } else { vec![CrateType::Rlib] };
 
     let sessopts = config::Options {
-        maybe_sysroot: options.maybe_sysroot.clone(),
+        sysroot: options.sysroot.clone(),
         search_paths: options.libs.clone(),
         crate_types,
         lint_opts,

tests/ui-fulldeps/run-compiler-twice.rs

@@ -46,7 +46,7 @@ fn main() {
 fn compile(code: String, output: PathBuf, sysroot: PathBuf, linker: Option<&Path>) {
     let mut opts = Options::default();
     opts.output_types = OutputTypes::new(&[(OutputType::Exe, None)]);
-    opts.maybe_sysroot = Some(sysroot);
+    opts.sysroot = sysroot;
 
     if let Some(linker) = linker {
         opts.cg.linker = Some(linker.to_owned());