Merge pull request rust-lang#4157 from RalfJung/rustup

Rustup

Author: RalfJung

compiler/rustc_ast/src/ast.rs

@@ -100,7 +100,7 @@ pub struct Path {
 impl PartialEq<Symbol> for Path {
     #[inline]
     fn eq(&self, symbol: &Symbol) -> bool {
-        self.segments.len() == 1 && { self.segments[0].ident.name == *symbol }
+        matches!(&self.segments[..], [segment] if segment.ident.name == *symbol)
     }
 }
 
@@ -121,13 +121,13 @@ impl Path {
     }
 
     pub fn is_global(&self) -> bool {
-        !self.segments.is_empty() && self.segments[0].ident.name == kw::PathRoot
+        self.segments.first().is_some_and(|segment| segment.ident.name == kw::PathRoot)
     }
 
     /// If this path is a single identifier with no arguments, does not ensure
     /// that the path resolves to a const param, the caller should check this.
     pub fn is_potential_trivial_const_arg(&self) -> bool {
-        self.segments.len() == 1 && self.segments[0].args.is_none()
+        matches!(self.segments[..], [PathSegment { args: None, .. }])
     }
 }
 

compiler/rustc_ast/src/attr/mod.rs

@@ -302,7 +302,7 @@ impl AttrItem {
 impl MetaItem {
     /// For a single-segment meta item, returns its name; otherwise, returns `None`.
     pub fn ident(&self) -> Option<Ident> {
-        if self.path.segments.len() == 1 { Some(self.path.segments[0].ident) } else { None }
+        if let [PathSegment { ident, .. }] = self.path.segments[..] { Some(ident) } else { None }
     }
 
     pub fn name_or_empty(&self) -> Symbol {

compiler/rustc_ast/src/mut_visit.rs

@@ -1813,10 +1813,10 @@ pub fn walk_flat_map_stmt<T: MutVisitor>(
         .into_iter()
         .map(|kind| Stmt { id, kind, span })
         .collect();
-    match stmts.len() {
-        0 => {}
-        1 => vis.visit_span(&mut stmts[0].span),
-        2.. => panic!(
+    match &mut stmts[..] {
+        [] => {}
+        [stmt] => vis.visit_span(&mut stmt.span),
+        _ => panic!(
             "cloning statement `NodeId`s is prohibited by default, \
              the visitor should implement custom statement visiting"
         ),

compiler/rustc_ast/src/util/comments.rs

@@ -39,7 +39,7 @@ pub fn beautify_doc_string(data: Symbol, kind: CommentKind) -> Symbol {
         let mut i = 0;
         let mut j = lines.len();
         // first line of all-stars should be omitted
-        if !lines.is_empty() && lines[0].chars().all(|c| c == '*') {
+        if lines.first().is_some_and(|line| line.chars().all(|c| c == '*')) {
             i += 1;
         }
 
@@ -97,7 +97,7 @@ pub fn beautify_doc_string(data: Symbol, kind: CommentKind) -> Symbol {
                 return None;
             }
         }
-        if lines.is_empty() { None } else { Some(lines[0][..i].into()) }
+        Some(lines.first()?[..i].to_string())
     }
 
     let data_s = data.as_str();

compiler/rustc_borrowck/src/polonius/dump.rs

@@ -1,7 +1,9 @@
 use std::io;
 
-use rustc_middle::mir::pretty::{PrettyPrintMirOptions, dump_mir_with_options};
-use rustc_middle::mir::{Body, ClosureRegionRequirements, PassWhere};
+use rustc_middle::mir::pretty::{
+    PassWhere, PrettyPrintMirOptions, create_dump_file, dump_enabled, dump_mir_to_writer,
+};
+use rustc_middle::mir::{Body, ClosureRegionRequirements};
 use rustc_middle::ty::TyCtxt;
 use rustc_session::config::MirIncludeSpans;
 
@@ -10,9 +12,6 @@ use crate::polonius::{LocalizedOutlivesConstraint, LocalizedOutlivesConstraintSe
 use crate::{BorrowckInferCtxt, RegionInferenceContext};
 
 /// `-Zdump-mir=polonius` dumps MIR annotated with NLL and polonius specific information.
-// Note: this currently duplicates most of NLL MIR, with some additions for the localized outlives
-// constraints. This is ok for now as this dump will change in the near future to an HTML file to
-// become more useful.
 pub(crate) fn dump_polonius_mir<'tcx>(
     infcx: &BorrowckInferCtxt<'tcx>,
     body: &Body<'tcx>,
@@ -26,25 +25,113 @@ pub(crate) fn dump_polonius_mir<'tcx>(
         return;
     }
 
+    if !dump_enabled(tcx, "polonius", body.source.def_id()) {
+        return;
+    }
+
     let localized_outlives_constraints = localized_outlives_constraints
         .expect("missing localized constraints with `-Zpolonius=next`");
 
-    // We want the NLL extra comments printed by default in NLL MIR dumps (they were removed in
-    // #112346). Specifying `-Z mir-include-spans` on the CLI still has priority: for example,
-    // they're always disabled in mir-opt tests to make working with blessed dumps easier.
+    let _: io::Result<()> = try {
+        let mut file = create_dump_file(tcx, "html", false, "polonius", &0, body)?;
+        emit_polonius_dump(
+            tcx,
+            body,
+            regioncx,
+            borrow_set,
+            localized_outlives_constraints,
+            closure_region_requirements,
+            &mut file,
+        )?;
+    };
+}
+
+/// The polonius dump consists of:
+/// - the NLL MIR
+/// - the list of polonius localized constraints
+/// - a mermaid graph of the CFG
+fn emit_polonius_dump<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    body: &Body<'tcx>,
+    regioncx: &RegionInferenceContext<'tcx>,
+    borrow_set: &BorrowSet<'tcx>,
+    localized_outlives_constraints: LocalizedOutlivesConstraintSet,
+    closure_region_requirements: &Option<ClosureRegionRequirements<'tcx>>,
+    out: &mut dyn io::Write,
+) -> io::Result<()> {
+    // Prepare the HTML dump file prologue.
+    writeln!(out, "<!DOCTYPE html>")?;
+    writeln!(out, "<html>")?;
+    writeln!(out, "<head><title>Polonius MIR dump</title></head>")?;
+    writeln!(out, "<body>")?;
+
+    // Section 1: the NLL + Polonius MIR.
+    writeln!(out, "<div>")?;
+    writeln!(out, "Raw MIR dump")?;
+    writeln!(out, "<code><pre>")?;
+    emit_html_mir(
+        tcx,
+        body,
+        regioncx,
+        borrow_set,
+        localized_outlives_constraints,
+        closure_region_requirements,
+        out,
+    )?;
+    writeln!(out, "</pre></code>")?;
+    writeln!(out, "</div>")?;
+
+    // Section 2: mermaid visualization of the CFG.
+    writeln!(out, "<div>")?;
+    writeln!(out, "Control-flow graph")?;
+    writeln!(out, "<code><pre class='mermaid'>")?;
+    emit_mermaid_cfg(body, out)?;
+    writeln!(out, "</pre></code>")?;
+    writeln!(out, "</div>")?;
+
+    // Finalize the dump with the HTML epilogue.
+    writeln!(
+        out,
+        "<script src='https://cdn.jsdelivr.net/npm/mermaid/dist/mermaid.min.js'></script>"
+    )?;
+    writeln!(out, "<script>")?;
+    writeln!(out, "mermaid.initialize({{ startOnLoad: false, maxEdges: 100 }});")?;
+    writeln!(out, "mermaid.run({{ querySelector: '.mermaid' }})")?;
+    writeln!(out, "</script>")?;
+    writeln!(out, "</body>")?;
+    writeln!(out, "</html>")?;
+
+    Ok(())
+}
+
+/// Emits the polonius MIR, as escaped HTML.
+fn emit_html_mir<'tcx>(
+    tcx: TyCtxt<'tcx>,
+    body: &Body<'tcx>,
+    regioncx: &RegionInferenceContext<'tcx>,
+    borrow_set: &BorrowSet<'tcx>,
+    localized_outlives_constraints: LocalizedOutlivesConstraintSet,
+    closure_region_requirements: &Option<ClosureRegionRequirements<'tcx>>,
+    out: &mut dyn io::Write,
+) -> io::Result<()> {
+    // Buffer the regular MIR dump to be able to escape it.
+    let mut buffer = Vec::new();
+
+    // We want the NLL extra comments printed by default in NLL MIR dumps. Specifying `-Z
+    // mir-include-spans` on the CLI still has priority.
     let options = PrettyPrintMirOptions {
         include_extra_comments: matches!(
             tcx.sess.opts.unstable_opts.mir_include_spans,
             MirIncludeSpans::On | MirIncludeSpans::Nll
         ),
     };
 
-    dump_mir_with_options(
+    dump_mir_to_writer(
         tcx,
-        false,
         "polonius",
         &0,
         body,
+        &mut buffer,
         |pass_where, out| {
             emit_polonius_mir(
                 tcx,
@@ -57,7 +144,27 @@ pub(crate) fn dump_polonius_mir<'tcx>(
             )
         },
         options,
-    );
+    )?;
+
+    // Escape the handful of characters that need it. We don't need to be particularly efficient:
+    // we're actually writing into a buffered writer already. Note that MIR dumps are valid UTF-8.
+    let buffer = String::from_utf8_lossy(&buffer);
+    for ch in buffer.chars() {
+        let escaped = match ch {
+            '>' => "&gt;",
+            '<' => "&lt;",
+            '&' => "&amp;",
+            '\'' => "&#39;",
+            '"' => "&quot;",
+            _ => {
+                // The common case, no escaping needed.
+                write!(out, "{}", ch)?;
+                continue;
+            }
+        };
+        write!(out, "{}", escaped)?;
+    }
+    Ok(())
 }
 
 /// Produces the actual NLL + Polonius MIR sections to emit during the dumping process.
@@ -102,3 +209,55 @@ fn emit_polonius_mir<'tcx>(
 
     Ok(())
 }
+
+/// Emits a mermaid flowchart of the CFG blocks and edges, similar to the graphviz version.
+fn emit_mermaid_cfg(body: &Body<'_>, out: &mut dyn io::Write) -> io::Result<()> {
+    use rustc_middle::mir::{TerminatorEdges, TerminatorKind};
+
+    // The mermaid chart type: a top-down flowchart.
+    writeln!(out, "flowchart TD")?;
+
+    // Emit the block nodes.
+    for (block_idx, block) in body.basic_blocks.iter_enumerated() {
+        let block_idx = block_idx.as_usize();
+        let cleanup = if block.is_cleanup { " (cleanup)" } else { "" };
+        writeln!(out, "{block_idx}[\"bb{block_idx}{cleanup}\"]")?;
+    }
+
+    // Emit the edges between blocks, from the terminator edges.
+    for (block_idx, block) in body.basic_blocks.iter_enumerated() {
+        let block_idx = block_idx.as_usize();
+        let terminator = block.terminator();
+        match terminator.edges() {
+            TerminatorEdges::None => {}
+            TerminatorEdges::Single(bb) => {
+                writeln!(out, "{block_idx} --> {}", bb.as_usize())?;
+            }
+            TerminatorEdges::Double(bb1, bb2) => {
+                if matches!(terminator.kind, TerminatorKind::FalseEdge { .. }) {
+                    writeln!(out, "{block_idx} --> {}", bb1.as_usize())?;
+                    writeln!(out, "{block_idx} -- imaginary --> {}", bb2.as_usize())?;
+                } else {
+                    writeln!(out, "{block_idx} --> {}", bb1.as_usize())?;
+                    writeln!(out, "{block_idx} -- unwind --> {}", bb2.as_usize())?;
+                }
+            }
+            TerminatorEdges::AssignOnReturn { return_, cleanup, .. } => {
+                for to_idx in return_ {
+                    writeln!(out, "{block_idx} --> {}", to_idx.as_usize())?;
+                }
+
+                if let Some(to_idx) = cleanup {
+                    writeln!(out, "{block_idx} -- unwind --> {}", to_idx.as_usize())?;
+                }
+            }
+            TerminatorEdges::SwitchInt { targets, .. } => {
+                for to_idx in targets.all_targets() {
+                    writeln!(out, "{block_idx} --> {}", to_idx.as_usize())?;
+                }
+            }
+        }
+    }
+
+    Ok(())
+}

compiler/rustc_builtin_macros/src/deriving/coerce_pointee.rs

@@ -157,7 +157,7 @@ pub(crate) fn expand_deriving_coerce_pointee(
         {
             cx.dcx().emit_err(RequiresMaybeSized {
                 span: pointee_ty_ident.span,
-                name: pointee_ty_ident.name.to_ident_string(),
+                name: pointee_ty_ident,
             });
             return;
         }
@@ -471,5 +471,5 @@ struct TooManyPointees {
 struct RequiresMaybeSized {
     #[primary_span]
     span: Span,
-    name: String,
+    name: Ident,
 }

compiler/rustc_codegen_cranelift/build_system/tests.rs

@@ -151,7 +151,7 @@ const EXTENDED_SYSROOT_SUITE: &[TestCase] = &[
         apply_patches(
             &runner.dirs,
             "coretests",
-            &runner.stdlib_source.join("library/core/tests"),
+            &runner.stdlib_source.join("library/coretests"),
             &LIBCORE_TESTS_SRC.to_path(&runner.dirs),
         );
 

compiler/rustc_codegen_cranelift/patches/0022-coretests-Disable-not-compiling-tests.patch

@@ -10,21 +10,20 @@ Cranelift doesn't support them yet
  library/core/tests/atomic.rs          |  4 ---
  4 files changed, 4 insertions(+), 50 deletions(-)
 
-diff --git a/lib.rs b/lib.rs
+diff --git a/tests/lib.rs b/tests/lib.rs
 index 1e336bf..35e6f54 100644
---- a/lib.rs
-+++ b/lib.rs
-@@ -2,6 +2,5 @@
- #![cfg(test)]
+--- a/tests/lib.rs
++++ b/tests/lib.rs
+@@ -2,5 +2,4 @@
  // tidy-alphabetical-start
 -#![cfg_attr(target_has_atomic = "128", feature(integer_atomics))]
  #![cfg_attr(test, feature(cfg_match))]
  #![feature(alloc_layout_extra)]
  #![feature(array_chunks)]
-diff --git a/atomic.rs b/atomic.rs
+diff --git a/tests/atomic.rs b/tests/atomic.rs
 index b735957..ea728b6 100644
---- a/atomic.rs
-+++ b/atomic.rs
+--- a/tests/atomic.rs
++++ b/tests/atomic.rs
 @@ -185,10 +185,6 @@ fn atomic_alignment() {
      assert_eq!(align_of::<AtomicU64>(), size_of::<AtomicU64>());
      #[cfg(target_has_atomic = "64")]