Rollup merge of #82269 - LeSeulArtichaut:cleanup-ppmode, r=spastorino

Cleanup `PpMode` and friends

This PR:
 - Separates `PpSourceMode` and `PpHirMode` to remove invalid states
 - Renames the variant to remove the redundant `Ppm` prefix
 - Adds basic documentation for the different pretty-print modes
 - Cleanups some code to make it more idiomatic

Not sure if this is actually useful, but it looks cleaner to me.

3 files changed, 92 insertions, 99 deletions

diff --git a/compiler/rustc_driver/src/pretty.rs b/compiler/rustc_driver/src/pretty.rs
index 17d2b3386f5..1dcc4d147ac 100644
--- a/compiler/rustc_driver/src/pretty.rs
+++ b/compiler/rustc_driver/src/pretty.rs
@@ -9,7 +9,7 @@ use rustc_hir_pretty as pprust_hir;
 use rustc_middle::hir::map as hir_map;
 use rustc_middle::ty::{self, TyCtxt};
 use rustc_mir::util::{write_mir_graphviz, write_mir_pretty};
-use rustc_session::config::{Input, PpMode, PpSourceMode};
+use rustc_session::config::{Input, PpHirMode, PpMode, PpSourceMode};
 use rustc_session::Session;
 use rustc_span::symbol::Ident;
 use rustc_span::FileName;
@@ -42,43 +42,41 @@ where
     F: FnOnce(&dyn PrinterSupport) -> A,
 {
     match *ppmode {
-        PpmNormal | PpmEveryBodyLoops | PpmExpanded => {
+        Normal | EveryBodyLoops | Expanded => {
             let annotation = NoAnn { sess, tcx };
             f(&annotation)
         }
 
-        PpmIdentified | PpmExpandedIdentified => {
+        Identified | ExpandedIdentified => {
             let annotation = IdentifiedAnnotation { sess, tcx };
             f(&annotation)
         }
-        PpmExpandedHygiene => {
+        ExpandedHygiene => {
             let annotation = HygieneAnnotation { sess };
             f(&annotation)
         }
-        _ => panic!("Should use call_with_pp_support_hir"),
     }
 }
-fn call_with_pp_support_hir<A, F>(ppmode: &PpSourceMode, tcx: TyCtxt<'_>, f: F) -> A
+fn call_with_pp_support_hir<A, F>(ppmode: &PpHirMode, tcx: TyCtxt<'_>, f: F) -> A
 where
     F: FnOnce(&dyn HirPrinterSupport<'_>, &hir::Crate<'_>) -> A,
 {
     match *ppmode {
-        PpmNormal => {
+        PpHirMode::Normal => {
             let annotation = NoAnn { sess: tcx.sess, tcx: Some(tcx) };
             f(&annotation, tcx.hir().krate())
         }
 
-        PpmIdentified => {
+        PpHirMode::Identified => {
             let annotation = IdentifiedAnnotation { sess: tcx.sess, tcx: Some(tcx) };
             f(&annotation, tcx.hir().krate())
         }
-        PpmTyped => {
+        PpHirMode::Typed => {
             abort_on_err(tcx.analysis(LOCAL_CRATE), tcx.sess);
 
             let annotation = TypedAnnotation { tcx, maybe_typeck_results: Cell::new(None) };
             tcx.dep_graph.with_ignore(|| f(&annotation, tcx.hir().krate()))
         }
-        _ => panic!("Should use call_with_pp_support"),
     }
 }
 
@@ -393,16 +391,13 @@ pub fn print_after_parsing(
 ) {
     let (src, src_name) = get_source(input, sess);
 
-    let mut out = String::new();
-
-    if let PpmSource(s) = ppm {
+    let out = if let Source(s) = ppm {
         // Silently ignores an identified node.
-        let out = &mut out;
         call_with_pp_support(&s, sess, None, move |annotation| {
             debug!("pretty printing source code {:?}", s);
             let sess = annotation.sess();
             let parse = &sess.parse_sess;
-            *out = pprust::print_crate(
+            pprust::print_crate(
                 sess.source_map(),
                 krate,
                 src_name,
@@ -413,7 +408,7 @@ pub fn print_after_parsing(
             )
         })
     } else {
-        unreachable!();
+        unreachable!()
     };
 
     write_or_print(&out, ofile);
@@ -433,17 +428,14 @@ pub fn print_after_hir_lowering<'tcx>(
 
     let (src, src_name) = get_source(input, tcx.sess);
 
-    let mut out = String::new();
-
-    match ppm {
-        PpmSource(s) => {
+    let out = match ppm {
+        Source(s) => {
             // Silently ignores an identified node.
-            let out = &mut out;
             call_with_pp_support(&s, tcx.sess, Some(tcx), move |annotation| {
                 debug!("pretty printing source code {:?}", s);
                 let sess = annotation.sess();
                 let parse = &sess.parse_sess;
-                *out = pprust::print_crate(
+                pprust::print_crate(
                     sess.source_map(),
                     krate,
                     src_name,
@@ -455,26 +447,20 @@ pub fn print_after_hir_lowering<'tcx>(
             })
         }
 
-        PpmHir(s) => {
-            let out = &mut out;
-            call_with_pp_support_hir(&s, tcx, move |annotation, krate| {
-                debug!("pretty printing source code {:?}", s);
-                let sess = annotation.sess();
-                let sm = sess.source_map();
-                *out = pprust_hir::print_crate(sm, krate, src_name, src, annotation.pp_ann())
-            })
-        }
+        Hir(s) => call_with_pp_support_hir(&s, tcx, move |annotation, krate| {
+            debug!("pretty printing HIR {:?}", s);
+            let sess = annotation.sess();
+            let sm = sess.source_map();
+            pprust_hir::print_crate(sm, krate, src_name, src, annotation.pp_ann())
+        }),
 
-        PpmHirTree(s) => {
-            let out = &mut out;
-            call_with_pp_support_hir(&s, tcx, move |_annotation, krate| {
-                debug!("pretty printing source code {:?}", s);
-                *out = format!("{:#?}", krate);
-            });
-        }
+        HirTree => call_with_pp_support_hir(&PpHirMode::Normal, tcx, move |_annotation, krate| {
+            debug!("pretty printing HIR tree");
+            format!("{:#?}", krate)
+        }),
 
         _ => unreachable!(),
-    }
+    };
 
     write_or_print(&out, ofile);
 }
@@ -493,14 +479,10 @@ fn print_with_analysis(
     tcx.analysis(LOCAL_CRATE)?;
 
     match ppm {
-        PpmMir | PpmMirCFG => match ppm {
-            PpmMir => write_mir_pretty(tcx, None, &mut out),
-            PpmMirCFG => write_mir_graphviz(tcx, None, &mut out),
-            _ => unreachable!(),
-        },
+        Mir => write_mir_pretty(tcx, None, &mut out).unwrap(),
+        MirCFG => write_mir_graphviz(tcx, None, &mut out).unwrap(),
         _ => unreachable!(),
     }
-    .unwrap();
 
     let out = std::str::from_utf8(&out).unwrap();
     write_or_print(out, ofile);
diff --git a/compiler/rustc_interface/src/passes.rs b/compiler/rustc_interface/src/passes.rs
index 6358855ac32..5217066bbef 100644
--- a/compiler/rustc_interface/src/passes.rs
+++ b/compiler/rustc_interface/src/passes.rs
@@ -350,7 +350,7 @@ fn configure_and_expand_inner<'a>(
         rustc_builtin_macros::test_harness::inject(&sess, &mut resolver, &mut krate)
     });
 
-    if let Some(PpMode::PpmSource(PpSourceMode::PpmEveryBodyLoops)) = sess.opts.pretty {
+    if let Some(PpMode::Source(PpSourceMode::EveryBodyLoops)) = sess.opts.pretty {
         tracing::debug!("replacing bodies with loop {{}}");
         util::ReplaceBodyWithLoop::new(&mut resolver).visit_crate(&mut krate);
     }
diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 81d6c3bbdbb..38da52b88f3 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -2057,40 +2057,21 @@ fn parse_pretty(
     debugging_opts: &DebuggingOptions,
     efmt: ErrorOutputType,
 ) -> Option<PpMode> {
-    let pretty = if debugging_opts.unstable_options {
-        matches.opt_default("pretty", "normal").map(|a| {
-            // stable pretty-print variants only
-            parse_pretty_inner(efmt, &a, false)
-        })
-    } else {
-        None
-    };
-
-    return if pretty.is_none() {
-        debugging_opts.unpretty.as_ref().map(|a| {
-            // extended with unstable pretty-print variants
-            parse_pretty_inner(efmt, &a, true)
-        })
-    } else {
-        pretty
-    };
-
     fn parse_pretty_inner(efmt: ErrorOutputType, name: &str, extended: bool) -> PpMode {
         use PpMode::*;
-        use PpSourceMode::*;
         let first = match (name, extended) {
-            ("normal", _) => PpmSource(PpmNormal),
-            ("identified", _) => PpmSource(PpmIdentified),
-            ("everybody_loops", true) => PpmSource(PpmEveryBodyLoops),
-            ("expanded", _) => PpmSource(PpmExpanded),
-            ("expanded,identified", _) => PpmSource(PpmExpandedIdentified),
-            ("expanded,hygiene", _) => PpmSource(PpmExpandedHygiene),
-            ("hir", true) => PpmHir(PpmNormal),
-            ("hir,identified", true) => PpmHir(PpmIdentified),
-            ("hir,typed", true) => PpmHir(PpmTyped),
-            ("hir-tree", true) => PpmHirTree(PpmNormal),
-            ("mir", true) => PpmMir,
-            ("mir-cfg", true) => PpmMirCFG,
+            ("normal", _) => Source(PpSourceMode::Normal),
+            ("identified", _) => Source(PpSourceMode::Identified),
+            ("everybody_loops", true) => Source(PpSourceMode::EveryBodyLoops),
+            ("expanded", _) => Source(PpSourceMode::Expanded),
+            ("expanded,identified", _) => Source(PpSourceMode::ExpandedIdentified),
+            ("expanded,hygiene", _) => Source(PpSourceMode::ExpandedHygiene),
+            ("hir", true) => Hir(PpHirMode::Normal),
+            ("hir,identified", true) => Hir(PpHirMode::Identified),
+            ("hir,typed", true) => Hir(PpHirMode::Typed),
+            ("hir-tree", true) => HirTree,
+            ("mir", true) => Mir,
+            ("mir-cfg", true) => MirCFG,
             _ => {
                 if extended {
                     early_error(
@@ -2119,6 +2100,18 @@ fn parse_pretty(
         tracing::debug!("got unpretty option: {:?}", first);
         first
     }
+
+    if debugging_opts.unstable_options {
+        if let Some(a) = matches.opt_default("pretty", "normal") {
+            // stable pretty-print variants only
+            return Some(parse_pretty_inner(efmt, &a, false));
+        }
+    }
+
+    debugging_opts.unpretty.as_ref().map(|a| {
+        // extended with unstable pretty-print variants
+        parse_pretty_inner(efmt, &a, true)
+    })
 }
 
 pub fn make_crate_type_option() -> RustcOptGroup {
@@ -2226,22 +2219,43 @@ impl fmt::Display for CrateType {
 
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub enum PpSourceMode {
-    PpmNormal,
-    PpmEveryBodyLoops,
-    PpmExpanded,
-    PpmIdentified,
-    PpmExpandedIdentified,
-    PpmExpandedHygiene,
-    PpmTyped,
+    /// `--pretty=normal`
+    Normal,
+    /// `-Zunpretty=everybody_loops`
+    EveryBodyLoops,
+    /// `--pretty=expanded`
+    Expanded,
+    /// `--pretty=identified`
+    Identified,
+    /// `--pretty=expanded,identified`
+    ExpandedIdentified,
+    /// `--pretty=expanded,hygiene`
+    ExpandedHygiene,
+}
+
+#[derive(Copy, Clone, PartialEq, Debug)]
+pub enum PpHirMode {
+    /// `-Zunpretty=hir`
+    Normal,
+    /// `-Zunpretty=hir,identified`
+    Identified,
+    /// `-Zunpretty=hir,typed`
+    Typed,
 }
 
 #[derive(Copy, Clone, PartialEq, Debug)]
 pub enum PpMode {
-    PpmSource(PpSourceMode),
-    PpmHir(PpSourceMode),
-    PpmHirTree(PpSourceMode),
-    PpmMir,
-    PpmMirCFG,
+    /// Options that print the source code, i.e.
+    /// `--pretty` and `-Zunpretty=everybody_loops`
+    Source(PpSourceMode),
+    /// Options that print the HIR, i.e. `-Zunpretty=hir`
+    Hir(PpHirMode),
+    /// `-Zunpretty=hir-tree`
+    HirTree,
+    /// `-Zunpretty=mir`
+    Mir,
+    /// `-Zunpretty=mir-cfg`
+    MirCFG,
 }
 
 impl PpMode {
@@ -2249,22 +2263,19 @@ impl PpMode {
         use PpMode::*;
         use PpSourceMode::*;
         match *self {
-            PpmSource(PpmNormal | PpmIdentified) => false,
+            Source(Normal | Identified) => false,
 
-            PpmSource(
-                PpmExpanded | PpmEveryBodyLoops | PpmExpandedIdentified | PpmExpandedHygiene,
-            )
-            | PpmHir(_)
-            | PpmHirTree(_)
-            | PpmMir
-            | PpmMirCFG => true,
-            PpmSource(PpmTyped) => panic!("invalid state"),
+            Source(Expanded | EveryBodyLoops | ExpandedIdentified | ExpandedHygiene)
+            | Hir(_)
+            | HirTree
+            | Mir
+            | MirCFG => true,
         }
     }
 
     pub fn needs_analysis(&self) -> bool {
         use PpMode::*;
-        matches!(*self, PpmMir | PpmMirCFG)
+        matches!(*self, Mir | MirCFG)
     }
 }