Rollup merge of rust-lang#82255 - nhwn:nonzero-err-as-bug, r=davidtwco

Make `treat_err_as_bug` Option<NonZeroUsize>

`rustc -Z treat-err-as-bug=N` already requires `N` to be nonzero when the argument is parsed, so changing the type from `Option<usize>` to `Option<NonZeroUsize>` is a low-hanging fruit in terms of layout optimization.

Author: Dylan-DPC

compiler/rustc_errors/src/lib.rs

@@ -30,6 +30,7 @@ use rustc_span::{Loc, MultiSpan, Span};
 
 use std::borrow::Cow;
 use std::hash::{Hash, Hasher};
+use std::num::NonZeroUsize;
 use std::panic;
 use std::path::Path;
 use std::{error, fmt};
@@ -359,7 +360,7 @@ pub struct HandlerFlags {
     pub can_emit_warnings: bool,
     /// If true, error-level diagnostics are upgraded to bug-level.
     /// (rustc: see `-Z treat-err-as-bug`)
-    pub treat_err_as_bug: Option<usize>,
+    pub treat_err_as_bug: Option<NonZeroUsize>,
     /// If true, immediately emit diagnostics that would otherwise be buffered.
     /// (rustc: see `-Z dont-buffer-diagnostics` and `-Z treat-err-as-bug`)
     pub dont_buffer_diagnostics: bool,
@@ -396,7 +397,7 @@ impl Handler {
     pub fn with_tty_emitter(
         color_config: ColorConfig,
         can_emit_warnings: bool,
-        treat_err_as_bug: Option<usize>,
+        treat_err_as_bug: Option<NonZeroUsize>,
         sm: Option<Lrc<SourceMap>>,
     ) -> Self {
         Self::with_tty_emitter_and_flags(
@@ -424,7 +425,7 @@ impl Handler {
 
     pub fn with_emitter(
         can_emit_warnings: bool,
-        treat_err_as_bug: Option<usize>,
+        treat_err_as_bug: Option<NonZeroUsize>,
         emitter: Box<dyn Emitter + sync::Send>,
     ) -> Self {
         Handler::with_emitter_and_flags(
@@ -841,7 +842,7 @@ impl HandlerInner {
     }
 
     fn treat_err_as_bug(&self) -> bool {
-        self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() >= c)
+        self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() >= c.get())
     }
 
     fn print_error_count(&mut self, registry: &Registry) {
@@ -950,7 +951,7 @@ impl HandlerInner {
         // This is technically `self.treat_err_as_bug()` but `delay_span_bug` is called before
         // incrementing `err_count` by one, so we need to +1 the comparing.
         // FIXME: Would be nice to increment err_count in a more coherent way.
-        if self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() + 1 >= c) {
+        if self.flags.treat_err_as_bug.map_or(false, |c| self.err_count() + 1 >= c.get()) {
             // FIXME: don't abort here if report_delayed_bugs is off
             self.span_bug(sp, msg);
         }
@@ -1023,7 +1024,7 @@ impl HandlerInner {
 
     fn panic_if_treat_err_as_bug(&self) {
         if self.treat_err_as_bug() {
-            match (self.err_count(), self.flags.treat_err_as_bug.unwrap_or(0)) {
+            match (self.err_count(), self.flags.treat_err_as_bug.map(|c| c.get()).unwrap_or(0)) {
                 (1, 1) => panic!("aborting due to `-Z treat-err-as-bug=1`"),
                 (0, _) | (1, _) => {}
                 (count, as_bug) => panic!(

compiler/rustc_interface/src/tests.rs

@@ -20,6 +20,7 @@ use rustc_target::spec::{CodeModel, LinkerFlavor, MergeFunctions, PanicStrategy}
 use rustc_target::spec::{RelocModel, RelroLevel, SplitDebuginfo, TlsModel};
 use std::collections::{BTreeMap, BTreeSet};
 use std::iter::FromIterator;
+use std::num::NonZeroUsize;
 use std::path::{Path, PathBuf};
 
 type CfgSpecs = FxHashSet<(String, Option<String>)>;
@@ -595,7 +596,7 @@ fn test_debugging_options_tracking_hash() {
     tracked!(tune_cpu, Some(String::from("abc")));
     tracked!(tls_model, Some(TlsModel::GeneralDynamic));
     tracked!(trap_unreachable, Some(false));
-    tracked!(treat_err_as_bug, Some(1));
+    tracked!(treat_err_as_bug, NonZeroUsize::new(1));
     tracked!(unleash_the_miri_inside_of_you, true);
     tracked!(use_ctors_section, Some(true));
     tracked!(verify_llvm_ir, true);

compiler/rustc_session/src/config.rs

@@ -2313,6 +2313,7 @@ crate mod dep_tracking {
     use std::collections::hash_map::DefaultHasher;
     use std::collections::BTreeMap;
     use std::hash::Hash;
+    use std::num::NonZeroUsize;
     use std::path::PathBuf;
 
     pub trait DepTrackingHash {
@@ -2353,6 +2354,7 @@ crate mod dep_tracking {
     impl_dep_tracking_hash_via_hash!(lint::Level);
     impl_dep_tracking_hash_via_hash!(Option<bool>);
     impl_dep_tracking_hash_via_hash!(Option<usize>);
+    impl_dep_tracking_hash_via_hash!(Option<NonZeroUsize>);
     impl_dep_tracking_hash_via_hash!(Option<String>);
     impl_dep_tracking_hash_via_hash!(Option<(String, u64)>);
     impl_dep_tracking_hash_via_hash!(Option<Vec<String>>);

compiler/rustc_session/src/options.rs

@@ -16,6 +16,7 @@ use std::collections::BTreeMap;
 
 use std::collections::hash_map::DefaultHasher;
 use std::hash::Hasher;
+use std::num::NonZeroUsize;
 use std::path::PathBuf;
 use std::str;
 
@@ -591,10 +592,10 @@ macro_rules! options {
             true
         }
 
-        fn parse_treat_err_as_bug(slot: &mut Option<usize>, v: Option<&str>) -> bool {
+        fn parse_treat_err_as_bug(slot: &mut Option<NonZeroUsize>, v: Option<&str>) -> bool {
             match v {
-                Some(s) => { *slot = s.parse().ok().filter(|&x| x != 0); slot.unwrap_or(0) != 0 }
-                None => { *slot = Some(1); true }
+                Some(s) => { *slot = s.parse().ok(); slot.is_some() }
+                None => { *slot = NonZeroUsize::new(1); true }
             }
         }
 
@@ -1141,7 +1142,7 @@ options! {DebuggingOptions, DebuggingSetter, basic_debugging_options,
         "for every macro invocation, print its name and arguments (default: no)"),
     trap_unreachable: Option<bool> = (None, parse_opt_bool, [TRACKED],
         "generate trap instructions for unreachable intrinsics (default: use target setting, usually yes)"),
-    treat_err_as_bug: Option<usize> = (None, parse_treat_err_as_bug, [TRACKED],
+    treat_err_as_bug: Option<NonZeroUsize> = (None, parse_treat_err_as_bug, [TRACKED],
         "treat error number `val` that occurs as bug"),
     trim_diagnostic_paths: bool = (true, parse_bool, [UNTRACKED],
         "in diagnostics, use heuristics to shorten paths referring to items"),