Auto merge of #65495 - Centril:rollup-tguwjt5, r=Centril

Rollup of 8 pull requests

Successful merges:

 - #65237 (Move debug_map assertions after check for err)
 - #65316 (make File::try_clone produce non-inheritable handles on Windows)
 - #65319 (InterpCx: make memory field public)
 - #65461 (Don't recommend ONCE_INIT in std::sync::Once)
 - #65465 (Move syntax::ext to a syntax_expand and refactor some attribute logic)
 - #65475 (add example for type_name)
 - #65478 (fmt::Write is about string slices, not byte slices)
 - #65486 (doc: fix typo in OsStrExt and OsStringExt)

Failed merges:

r? @ghost

Author: bors

Cargo.lock

@@ -3112,6 +3112,7 @@ dependencies = [
  "serialize",
  "smallvec",
  "syntax",
+ "syntax_expand",
  "syntax_pos",
 ]
 
@@ -3427,6 +3428,7 @@ dependencies = [
  "rustc_target",
  "serialize",
  "syntax",
+ "syntax_expand",
  "syntax_pos",
  "tempfile",
 ]
@@ -3559,6 +3561,7 @@ dependencies = [
  "serialize",
  "smallvec",
  "syntax",
+ "syntax_expand",
  "syntax_ext",
  "syntax_pos",
  "tempfile",
@@ -3630,6 +3633,7 @@ dependencies = [
  "smallvec",
  "stable_deref_trait",
  "syntax",
+ "syntax_expand",
  "syntax_pos",
 ]
 
@@ -3678,6 +3682,7 @@ dependencies = [
  "rustc_index",
  "rustc_target",
  "syntax",
+ "syntax_expand",
  "syntax_pos",
 ]
 
@@ -3695,6 +3700,7 @@ dependencies = [
  "rustc",
  "rustc_metadata",
  "syntax",
+ "syntax_expand",
  "syntax_pos",
 ]
 
@@ -3723,6 +3729,7 @@ dependencies = [
  "rustc_metadata",
  "smallvec",
  "syntax",
+ "syntax_expand",
  "syntax_pos",
 ]
 
@@ -4336,6 +4343,25 @@ dependencies = [
  "syntax_pos",
 ]
 
+[[package]]
+name = "syntax_expand"
+version = "0.0.0"
+dependencies = [
+ "bitflags",
+ "lazy_static 1.3.0",
+ "log",
+ "rustc_data_structures",
+ "rustc_errors",
+ "rustc_index",
+ "rustc_lexer",
+ "rustc_target",
+ "scoped-tls",
+ "serialize",
+ "smallvec",
+ "syntax",
+ "syntax_pos",
+]
+
 [[package]]
 name = "syntax_ext"
 version = "0.0.0"
@@ -4347,6 +4373,7 @@ dependencies = [
  "rustc_target",
  "smallvec",
  "syntax",
+ "syntax_expand",
  "syntax_pos",
 ]
 

src/libcore/any.rs

@@ -445,6 +445,15 @@ impl TypeId {
 ///
 /// The current implementation uses the same infrastructure as compiler
 /// diagnostics and debuginfo, but this is not guaranteed.
+///
+/// # Example
+///
+/// ```rust
+/// assert_eq!(
+///     std::any::type_name::<Option<String>>(),
+///     "core::option::Option<alloc::string::String>",
+/// );
+/// ```
 #[stable(feature = "type_name", since = "1.38.0")]
 #[rustc_const_unstable(feature = "const_type_name")]
 pub const fn type_name<T: ?Sized>() -> &'static str {

src/libcore/fmt/builders.rs

@@ -775,10 +775,10 @@ impl<'a, 'b: 'a> DebugMap<'a, 'b> {
                reason = "recently added",
                issue = "62482")]
     pub fn key(&mut self, key: &dyn fmt::Debug) -> &mut DebugMap<'a, 'b> {
-        assert!(!self.has_key, "attempted to begin a new map entry \
-                                without completing the previous one");
-
         self.result = self.result.and_then(|_| {
+            assert!(!self.has_key, "attempted to begin a new map entry \
+                                    without completing the previous one");
+
             if self.is_pretty() {
                 if !self.has_fields {
                     self.fmt.write_str("\n")?;
@@ -839,9 +839,9 @@ impl<'a, 'b: 'a> DebugMap<'a, 'b> {
                reason = "recently added",
                issue = "62482")]
     pub fn value(&mut self, value: &dyn fmt::Debug) -> &mut DebugMap<'a, 'b> {
-        assert!(self.has_key, "attempted to format a map value before its key");
-
         self.result = self.result.and_then(|_| {
+            assert!(self.has_key, "attempted to format a map value before its key");
+
             if self.is_pretty() {
                 let mut slot = None;
                 let mut writer = PadAdapter::wrap(&mut self.fmt, &mut slot, &mut self.state);
@@ -924,9 +924,11 @@ impl<'a, 'b: 'a> DebugMap<'a, 'b> {
     /// ```
     #[stable(feature = "debug_builders", since = "1.2.0")]
     pub fn finish(&mut self) -> fmt::Result {
-        assert!(!self.has_key, "attempted to finish a map with a partial entry");
+        self.result.and_then(|_| {
+            assert!(!self.has_key, "attempted to finish a map with a partial entry");
 
-        self.result.and_then(|_| self.fmt.write_str("}"))
+            self.fmt.write_str("}")
+        })
     }
 
     fn is_pretty(&self) -> bool {

src/libcore/fmt/mod.rs

@@ -108,10 +108,10 @@ pub struct Error;
 /// [`io::Write`]: ../../std/io/trait.Write.html
 #[stable(feature = "rust1", since = "1.0.0")]
 pub trait Write {
-    /// Writes a slice of bytes into this writer, returning whether the write
+    /// Writes a string slice into this writer, returning whether the write
     /// succeeded.
     ///
-    /// This method can only succeed if the entire byte slice was successfully
+    /// This method can only succeed if the entire string slice was successfully
     /// written, and this method will not return until all data has been
     /// written or an error occurs.
     ///

src/libcore/tests/fmt/builders.rs

@@ -319,6 +319,46 @@ mod debug_map {
                    format!("{:#?}", Bar));
     }
 
+    #[test]
+    fn test_entry_err() {
+        // Ensure errors in a map entry don't trigger panics (#65231)
+        use std::fmt::Write;
+
+        struct ErrorFmt;
+
+        impl fmt::Debug for ErrorFmt {
+            fn fmt(&self, _: &mut fmt::Formatter<'_>) -> fmt::Result {
+                Err(fmt::Error)
+            }
+        }
+
+        struct KeyValue<K, V>(usize, K, V);
+
+        impl<K, V> fmt::Debug for KeyValue<K, V>
+        where
+            K: fmt::Debug,
+            V: fmt::Debug,
+        {
+            fn fmt(&self, fmt: &mut fmt::Formatter<'_>) -> fmt::Result {
+                let mut map = fmt.debug_map();
+
+                for _ in 0..self.0 {
+                    map.entry(&self.1, &self.2);
+                }
+
+                map.finish()
+            }
+        }
+
+        let mut buf = String::new();
+
+        assert!(write!(&mut buf, "{:?}", KeyValue(1, ErrorFmt, "bar")).is_err());
+        assert!(write!(&mut buf, "{:?}", KeyValue(1, "foo", ErrorFmt)).is_err());
+
+        assert!(write!(&mut buf, "{:?}", KeyValue(2, ErrorFmt, "bar")).is_err());
+        assert!(write!(&mut buf, "{:?}", KeyValue(2, "foo", ErrorFmt)).is_err());
+    }
+
     #[test]
     #[should_panic]
     fn test_invalid_key_when_entry_is_incomplete() {

src/librustc/Cargo.toml

@@ -29,6 +29,7 @@ rustc_index = { path = "../librustc_index" }
 errors = { path = "../librustc_errors", package = "rustc_errors" }
 rustc_serialize = { path = "../libserialize", package = "serialize" }
 syntax = { path = "../libsyntax" }
+syntax_expand = { path = "../libsyntax_expand" }
 syntax_pos = { path = "../libsyntax_pos" }
 backtrace = "0.3.3"
 parking_lot = "0.9"

src/librustc/hir/def.rs

@@ -6,7 +6,7 @@ use crate::ty;
 use crate::util::nodemap::DefIdMap;
 
 use syntax::ast;
-use syntax::ext::base::MacroKind;
+use syntax_expand::base::MacroKind;
 use syntax::ast::NodeId;
 use syntax_pos::Span;
 use rustc_macros::HashStable;

src/librustc/hir/lowering.rs

@@ -64,15 +64,15 @@ use syntax::ast;
 use syntax::ptr::P as AstP;
 use syntax::ast::*;
 use syntax::errors;
-use syntax::ext::base::SpecialDerives;
-use syntax::ext::hygiene::ExpnId;
+use syntax_expand::base::SpecialDerives;
 use syntax::print::pprust;
-use syntax::tokenstream::{TokenStream, TokenTree};
 use syntax::parse::token::{self, Nonterminal, Token};
+use syntax::tokenstream::{TokenStream, TokenTree};
 use syntax::sess::ParseSess;
 use syntax::source_map::{respan, ExpnData, ExpnKind, DesugaringKind, Spanned};
 use syntax::symbol::{kw, sym, Symbol};
 use syntax::visit::{self, Visitor};
+use syntax_pos::hygiene::ExpnId;
 use syntax_pos::Span;
 
 const HIR_ID_COUNTER_LOCKED: u32 = 0xFFFFFFFF;

src/librustc/hir/lowering/item.rs

@@ -18,7 +18,7 @@ use smallvec::SmallVec;
 use syntax::attr;
 use syntax::ast::*;
 use syntax::visit::{self, Visitor};
-use syntax::ext::base::SpecialDerives;
+use syntax_expand::base::SpecialDerives;
 use syntax::source_map::{respan, DesugaringKind, Spanned};
 use syntax::symbol::{kw, sym};
 use syntax_pos::Span;

src/librustc/hir/map/def_collector.rs

@@ -2,7 +2,7 @@ use crate::hir::map::definitions::*;
 use crate::hir::def_id::DefIndex;
 
 use syntax::ast::*;
-use syntax::ext::hygiene::ExpnId;
+use syntax_expand::hygiene::ExpnId;
 use syntax::visit;
 use syntax::symbol::{kw, sym};
 use syntax::parse::token::{self, Token};