Cleanup sysroot locating a bit

compiler/rustc_codegen_ssa/src/back/link.rs

@@ -1286,8 +1286,7 @@ fn link_sanitizer_runtime(
         if path.exists() {
             sess.target_tlib_path.dir.clone()
         } else {
-            let default_sysroot =
-                filesearch::get_or_default_sysroot().expect("Failed finding sysroot");
+            let default_sysroot = filesearch::get_or_default_sysroot();
             let default_tlib =
                 filesearch::make_target_lib_path(&default_sysroot, sess.opts.target_triple.tuple());
             default_tlib

compiler/rustc_error_messages/src/lib.rs

@@ -107,8 +107,8 @@ impl From<Vec<FluentError>> for TranslationBundleError {
 /// (overriding any conflicting messages).
 #[instrument(level = "trace")]
 pub fn fluent_bundle(
-    mut user_provided_sysroot: Option<PathBuf>,
-    mut sysroot_candidates: Vec<PathBuf>,
+    sysroot: PathBuf,
+    sysroot_candidates: Vec<PathBuf>,
     requested_locale: Option<LanguageIdentifier>,
     additional_ftl_path: Option<&Path>,
     with_directionality_markers: bool,
@@ -142,7 +142,7 @@ 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 mut sysroot in Some(sysroot).into_iter().chain(sysroot_candidates.into_iter()) {
             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/filesearch.rs

@@ -160,8 +160,7 @@ fn current_dll_path() -> Result<PathBuf, String> {
 
 pub fn sysroot_candidates() -> SmallVec<[PathBuf; 2]> {
     let target = crate::config::host_tuple();
-    let mut sysroot_candidates: SmallVec<[PathBuf; 2]> =
-        smallvec![get_or_default_sysroot().expect("Failed finding sysroot")];
+    let mut sysroot_candidates: SmallVec<[PathBuf; 2]> = smallvec![get_or_default_sysroot()];
     let path = current_dll_path().and_then(|s| try_canonicalize(s).map_err(|e| e.to_string()));
     if let Ok(dll) = path {
         // use `parent` twice to chop off the file name and then also the
@@ -195,12 +194,12 @@ pub fn sysroot_candidates() -> SmallVec<[PathBuf; 2]> {
 /// Returns the provided sysroot or calls [`get_or_default_sysroot`] if it's none.
 /// Panics if [`get_or_default_sysroot`]  returns an error.
 pub fn materialize_sysroot(maybe_sysroot: Option<PathBuf>) -> PathBuf {
-    maybe_sysroot.unwrap_or_else(|| get_or_default_sysroot().expect("Failed finding sysroot"))
+    maybe_sysroot.unwrap_or_else(|| get_or_default_sysroot())
 }
 
 /// This function checks if sysroot is found using env::args().next(), and if it
 /// is not found, finds sysroot from current rustc_driver dll.
-pub fn get_or_default_sysroot() -> Result<PathBuf, String> {
+pub fn get_or_default_sysroot() -> PathBuf {
     // Follow symlinks. If the resolved path is relative, make it absolute.
     fn canonicalize(path: PathBuf) -> PathBuf {
         let path = try_canonicalize(&path).unwrap_or(path);
@@ -255,30 +254,25 @@ pub fn get_or_default_sysroot() -> Result<PathBuf, String> {
     // binary able to locate Rust libraries in systems using content-addressable
     // storage (CAS).
     fn from_env_args_next() -> Option<PathBuf> {
-        match env::args_os().next() {
-            Some(first_arg) => {
-                let mut p = PathBuf::from(first_arg);
-
-                // Check if sysroot is found using env::args().next() only if the rustc in argv[0]
-                // is a symlink (see #79253). We might want to change/remove it to conform with
-                // https://www.gnu.org/prep/standards/standards.html#Finding-Program-Files in the
-                // future.
-                if fs::read_link(&p).is_err() {
-                    // Path is not a symbolic link or does not exist.
-                    return None;
-                }
-
-                // Pop off `bin/rustc`, obtaining the suspected sysroot.
-                p.pop();
-                p.pop();
-                // Look for the target rustlib directory in the suspected sysroot.
-                let mut rustlib_path = rustc_target::relative_target_rustlib_path(&p, "dummy");
-                rustlib_path.pop(); // pop off the dummy target.
-                rustlib_path.exists().then_some(p)
-            }
-            None => None,
+        let mut p = PathBuf::from(env::args_os().next()?);
+
+        // Check if sysroot is found using env::args().next() only if the rustc in argv[0]
+        // is a symlink (see #79253). We might want to change/remove it to conform with
+        // https://www.gnu.org/prep/standards/standards.html#Finding-Program-Files in the
+        // future.
+        if fs::read_link(&p).is_err() {
+            // Path is not a symbolic link or does not exist.
+            return None;
         }
+
+        // Pop off `bin/rustc`, obtaining the suspected sysroot.
+        p.pop();
+        p.pop();
+        // Look for the target rustlib directory in the suspected sysroot.
+        let mut rustlib_path = rustc_target::relative_target_rustlib_path(&p, "dummy");
+        rustlib_path.pop(); // pop off the dummy target.
+        rustlib_path.exists().then_some(p)
     }
 
-    Ok(from_env_args_next().unwrap_or(default_from_rustc_driver_dll()?))
+    from_env_args_next().unwrap_or(default_from_rustc_driver_dll().expect("Failed finding sysroot"))
 }

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],
 

compiler/rustc_session/src/session.rs

@@ -143,7 +143,6 @@ pub struct Session {
     pub target: Target,
     pub host: Target,
     pub opts: config::Options,
-    pub host_tlib_path: Arc<SearchPath>,
     pub target_tlib_path: Arc<SearchPath>,
     pub psess: ParseSess,
     pub sysroot: PathBuf,
@@ -1042,6 +1041,7 @@ pub fn build_session(
 
     let host_triple = config::host_tuple();
     let target_triple = sopts.target_triple.tuple();
+    // FIXME use host sysroot?
     let host_tlib_path = Arc::new(SearchPath::from_sysroot_and_triple(&sysroot, host_triple));
     let target_tlib_path = if host_triple == target_triple {
         // Use the same `SearchPath` if host and target triple are identical to avoid unnecessary
@@ -1070,7 +1070,6 @@ pub fn build_session(
         target,
         host,
         opts: sopts,
-        host_tlib_path,
         target_tlib_path,
         psess,
         sysroot,

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)
@@ -729,12 +732,7 @@ impl Options {
         let target = parse_target_triple(early_dcx, matches);
         let maybe_sysroot = matches.opt_str("sysroot").map(PathBuf::from);
 
-        let sysroot = match &maybe_sysroot {
-            Some(s) => s.clone(),
-            None => {
-                rustc_session::filesearch::get_or_default_sysroot().expect("Failed finding sysroot")
-            }
-        };
+        let sysroot = rustc_session::filesearch::materialize_sysroot(maybe_sysroot.clone());
 
         let libs = matches
             .opt_strs("L")
@@ -834,6 +832,7 @@ 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());