Auto merge of #129817 - matthiaskrgr:rollup-ll2ld5m, r=matthiaskrgr

Rollup of 12 pull requests

Successful merges:

 - #129659 (const fn stability checking: also check declared language features)
 - #129711 (Expand NLL MIR dumps)
 - #129730 (f32 docs: define 'arithmetic' operations)
 - #129733 (Subtree update of `rust-analyzer`)
 - #129749 (llvm-wrapper: adapt for LLVM API changes)
 - #129757 (Add a test for trait solver overflow in MIR inliner cycle detection)
 - #129760 (Make the "detect-old-time" UI test more representative)
 - #129767 (Remove `#[macro_use] extern crate tracing`, round 4)
 - #129774 (Remove `#[macro_use] extern crate tracing` from rustdoc and rustfmt)
 - #129785 (Miri subtree update)
 - #129791 (mark joboet as on vacation)
 - #129812 (interpret, codegen: tweak some comments and checks regarding Box with custom allocator)

Failed merges:

 - #129777 (Add `unreachable_pub`, round 4)

r? `@ghost`
`@rustbot` modify labels: rollup

2 files changed, 38 insertions, 2 deletions

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index fbdb3cb1534..945bab6887e 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -3369,3 +3369,25 @@ pub enum FunctionReturn {
     /// Replace returns with jumps to thunk, without emitting the thunk.
     ThunkExtern,
 }
+
+/// Whether extra span comments are included when dumping MIR, via the `-Z mir-include-spans` flag.
+/// By default, only enabled in the NLL MIR dumps, and disabled in all other passes.
+#[derive(Clone, Copy, Default, PartialEq, Debug)]
+pub enum MirIncludeSpans {
+    Off,
+    On,
+    /// Default: include extra comments in NLL MIR dumps only. Can be ignored and considered as
+    /// `Off` in all other cases.
+    #[default]
+    Nll,
+}
+
+impl MirIncludeSpans {
+    /// Unless opting into extra comments for all passes, they can be considered disabled.
+    /// The cases where a distinction between on/off and a per-pass value can exist will be handled
+    /// in the passes themselves: i.e. the `Nll` value is considered off for all intents and
+    /// purposes, except for the NLL MIR dump pass.
+    pub fn is_enabled(self) -> bool {
+        self == MirIncludeSpans::On
+    }
+}
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 4492ad09357..37077901e0c 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -445,6 +445,8 @@ mod desc {
     pub const parse_llvm_module_flag: &str = "<key>:<type>:<value>:<behavior>. Type must currently be `u32`. Behavior should be one of (`error`, `warning`, `require`, `override`, `append`, `appendunique`, `max`, `min`)";
     pub const parse_function_return: &str = "`keep` or `thunk-extern`";
     pub const parse_wasm_c_abi: &str = "`legacy` or `spec`";
+    pub const parse_mir_include_spans: &str =
+        "either a boolean (`yes`, `no`, `on`, `off`, etc), or `nll` (default: `nll`)";
 }
 
 mod parse {
@@ -1488,6 +1490,17 @@ mod parse {
         }
         true
     }
+
+    pub(crate) fn parse_mir_include_spans(slot: &mut MirIncludeSpans, v: Option<&str>) -> bool {
+        *slot = match v {
+            Some("on" | "yes" | "y" | "true") | None => MirIncludeSpans::On,
+            Some("off" | "no" | "n" | "false") => MirIncludeSpans::Off,
+            Some("nll") => MirIncludeSpans::Nll,
+            _ => return false,
+        };
+
+        true
+    }
 }
 
 options! {
@@ -1848,8 +1861,9 @@ options! {
         specified passes to be enabled, overriding all other checks. In particular, this will \
         enable unsound (known-buggy and hence usually disabled) passes without further warning! \
         Passes that are not specified are enabled or disabled by other flags as usual."),
-    mir_include_spans: bool = (false, parse_bool, [UNTRACKED],
-        "use line numbers relative to the function in mir pretty printing"),
+    mir_include_spans: MirIncludeSpans = (MirIncludeSpans::default(), parse_mir_include_spans, [UNTRACKED],
+        "include extra comments in mir pretty printing, like line numbers and statement indices, \
+         details about types, etc. (boolean for all passes, 'nll' to enable in NLL MIR only, default: 'nll')"),
     mir_keep_place_mention: bool = (false, parse_bool, [TRACKED],
         "keep place mention MIR statements, interpreted e.g., by miri; implies -Zmir-opt-level=0 \
         (default: no)"),