6 files changed, 24 insertions, 14 deletions
diff --git a/compiler/rustc_session/src/errors.rs b/compiler/rustc_session/src/errors.rs
index 25d84506efa..e72b76cfee9 100644
--- a/compiler/rustc_session/src/errors.rs
+++ b/compiler/rustc_session/src/errors.rs
@@ -116,6 +116,10 @@ pub struct StackProtectorNotSupportedForTarget<'a> {
 }
 
 #[derive(Diagnostic)]
+#[diag(session_branch_protection_requires_aarch64)]
+pub(crate) struct BranchProtectionRequiresAArch64;
+
+#[derive(Diagnostic)]
 #[diag(session_split_debuginfo_unstable_platform)]
 pub struct SplitDebugInfoUnstablePlatform {
     pub debuginfo: SplitDebuginfo,
diff --git a/compiler/rustc_session/src/filesearch.rs b/compiler/rustc_session/src/filesearch.rs
index 1855a49c1ec..6f1b31ff9c3 100644
--- a/compiler/rustc_session/src/filesearch.rs
+++ b/compiler/rustc_session/src/filesearch.rs
@@ -122,7 +122,7 @@ pub fn sysroot_candidates() -> SmallVec<[PathBuf; 2]> {
     let target = crate::config::host_triple();
     let mut sysroot_candidates: SmallVec<[PathBuf; 2]> =
         smallvec![get_or_default_sysroot().expect("Failed finding sysroot")];
-    let path = current_dll_path().and_then(|s| Ok(s.canonicalize().map_err(|e| e.to_string())?));
+    let path = current_dll_path().and_then(|s| s.canonicalize().map_err(|e| e.to_string()));
     if let Ok(dll) = path {
         // use `parent` twice to chop off the file name and then also the
         // directory containing the dll which should be either `lib` or `bin`.
@@ -165,7 +165,7 @@ pub fn get_or_default_sysroot() -> Result<PathBuf, String> {
     }
 
     fn default_from_rustc_driver_dll() -> Result<PathBuf, String> {
-        let dll = current_dll_path().and_then(|s| Ok(canonicalize(s)))?;
+        let dll = current_dll_path().map(|s| canonicalize(s))?;
 
         // `dll` will be in one of the following two:
         // - compiler's libdir: $sysroot/lib/*.dll
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 9e130287104..40bc669707a 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -1421,6 +1421,8 @@ options! {
         "run all passes except codegen; no output"),
     no_generate_arange_section: bool = (false, parse_no_flag, [TRACKED],
         "omit DWARF address ranges that give faster lookups"),
+    no_jump_tables: bool = (false, parse_no_flag, [TRACKED],
+        "disable the jump tables and lookup tables that can be generated from a switch case lowering"),
     no_leak_check: bool = (false, parse_no_flag, [UNTRACKED],
         "disable the 'leak check' for subtyping; unsound, but useful for tests"),
     no_link: bool = (false, parse_no_flag, [TRACKED],
diff --git a/compiler/rustc_session/src/parse.rs b/compiler/rustc_session/src/parse.rs
index f9f4f2979c4..2aa8ca9e4a9 100644
--- a/compiler/rustc_session/src/parse.rs
+++ b/compiler/rustc_session/src/parse.rs
@@ -122,7 +122,7 @@ pub fn feature_err_issue<'a>(
 /// Construct a future incompatibility diagnostic for a feature gate.
 ///
 /// This diagnostic is only a warning and *does not cause compilation to fail*.
-pub fn feature_warn<'a>(sess: &'a ParseSess, feature: Symbol, span: Span, explain: &str) {
+pub fn feature_warn(sess: &ParseSess, feature: Symbol, span: Span, explain: &str) {
     feature_warn_issue(sess, feature, span, GateIssue::Language, explain);
 }
 
@@ -134,8 +134,8 @@ pub fn feature_warn<'a>(sess: &'a ParseSess, feature: Symbol, span: Span, explai
 /// Almost always, you want to use this for a language feature. If so, prefer `feature_warn`.
 #[allow(rustc::diagnostic_outside_of_impl)]
 #[allow(rustc::untranslatable_diagnostic)]
-pub fn feature_warn_issue<'a>(
-    sess: &'a ParseSess,
+pub fn feature_warn_issue(
+    sess: &ParseSess,
     feature: Symbol,
     span: Span,
     issue: GateIssue,
@@ -160,7 +160,7 @@ pub fn feature_warn_issue<'a>(
 }
 
 /// Adds the diagnostics for a feature to an existing error.
-pub fn add_feature_diagnostics<'a>(err: &mut Diagnostic, sess: &'a ParseSess, feature: Symbol) {
+pub fn add_feature_diagnostics(err: &mut Diagnostic, sess: &ParseSess, feature: Symbol) {
     add_feature_diagnostics_for_issue(err, sess, feature, GateIssue::Language);
 }
 
@@ -169,9 +169,9 @@ pub fn add_feature_diagnostics<'a>(err: &mut Diagnostic, sess: &'a ParseSess, fe
 /// This variant allows you to control whether it is a library or language feature.
 /// Almost always, you want to use this for a language feature. If so, prefer
 /// `add_feature_diagnostics`.
-pub fn add_feature_diagnostics_for_issue<'a>(
+pub fn add_feature_diagnostics_for_issue(
     err: &mut Diagnostic,
-    sess: &'a ParseSess,
+    sess: &ParseSess,
     feature: Symbol,
     issue: GateIssue,
 ) {
diff --git a/compiler/rustc_session/src/session.rs b/compiler/rustc_session/src/session.rs
index 8859b76d289..01a9b100088 100644
--- a/compiler/rustc_session/src/session.rs
+++ b/compiler/rustc_session/src/session.rs
@@ -3,10 +3,10 @@ use crate::code_stats::CodeStats;
 pub use crate::code_stats::{DataTypeKind, FieldInfo, SizeKind, VariantInfo};
 use crate::config::{self, CrateType, InstrumentCoverage, OptLevel, OutputType, SwitchWithOptPath};
 use crate::errors::{
-    CannotEnableCrtStaticLinux, CannotMixAndMatchSanitizers, LinkerPluginToWindowsNotSupported,
-    NotCircumventFeature, ProfileSampleUseFileDoesNotExist, ProfileUseFileDoesNotExist,
-    SanitizerCfiEnabled, SanitizerNotSupported, SanitizersNotSupported, SkippingConstChecks,
-    SplitDebugInfoUnstablePlatform, StackProtectorNotSupportedForTarget,
+    BranchProtectionRequiresAArch64, CannotEnableCrtStaticLinux, CannotMixAndMatchSanitizers,
+    LinkerPluginToWindowsNotSupported, NotCircumventFeature, ProfileSampleUseFileDoesNotExist,
+    ProfileUseFileDoesNotExist, SanitizerCfiEnabled, SanitizerNotSupported, SanitizersNotSupported,
+    SkippingConstChecks, SplitDebugInfoUnstablePlatform, StackProtectorNotSupportedForTarget,
     TargetRequiresUnwindTables, UnleashedFeatureHelp, UnstableVirtualFunctionElimination,
     UnsupportedDwarfVersion,
 };
@@ -1323,7 +1323,7 @@ pub fn build_session(
     let warnings_allow = sopts
         .lint_opts
         .iter()
-        .rfind(|&&(ref key, _)| *key == "warnings")
+        .rfind(|&(key, _)| *key == "warnings")
         .map_or(false, |&(_, level)| level == lint::Allow);
     let cap_lints_allow = sopts.lint_cap.map_or(false, |cap| cap == lint::Allow);
     let can_emit_warnings = !(warnings_allow || cap_lints_allow);
@@ -1565,6 +1565,10 @@ fn validate_commandline_args_with_session_available(sess: &Session) {
         }
     }
 
+    if sess.opts.unstable_opts.branch_protection.is_some() && sess.target.arch != "aarch64" {
+        sess.emit_err(BranchProtectionRequiresAArch64);
+    }
+
     if let Some(dwarf_version) = sess.opts.unstable_opts.dwarf_version {
         if dwarf_version > 5 {
             sess.emit_err(UnsupportedDwarfVersion { dwarf_version });
diff --git a/compiler/rustc_session/src/utils.rs b/compiler/rustc_session/src/utils.rs
index e65b6891e32..b996d36a318 100644
--- a/compiler/rustc_session/src/utils.rs
+++ b/compiler/rustc_session/src/utils.rs
@@ -3,7 +3,7 @@ use rustc_data_structures::profiling::VerboseTimingGuard;
 use std::path::{Path, PathBuf};
 
 impl Session {
-    pub fn timer<'a>(&'a self, what: &'static str) -> VerboseTimingGuard<'a> {
+    pub fn timer(&self, what: &'static str) -> VerboseTimingGuard<'_> {
         self.prof.verbose_generic_activity(what)
     }
     pub fn time<R>(&self, what: &'static str, f: impl FnOnce() -> R) -> R {