Auto merge of rust-lang#140999 - hkBst:update-escaper, r=nnethercote

update to literal-escaper 0.0.4 for better API without `unreachable` and faster string parsing

This is the replacement for just the part of rust-lang#138163 dealing with the changed API of unescape functionality, since that got moved into its own crate.

<del>This uses an unpublished version of literal-escaper (https://github.com/rust-lang/literal-escaper/pull/8).</del>

r? `@nnethercote`

Author: bors

Cargo.lock

@@ -55,8 +55,7 @@ rustflags = ["-Cpanic=abort"]
 rustflags = ["-Cpanic=abort"]
 
 [patch.crates-io]
-# See comments in `library/rustc-std-workspace-core/README.md` for what's going on
-# here
+# See comments in `library/rustc-std-workspace-core/README.md` for what's going on here
 rustc-std-workspace-core = { path = 'rustc-std-workspace-core' }
 rustc-std-workspace-alloc = { path = 'rustc-std-workspace-alloc' }
 rustc-std-workspace-std = { path = 'rustc-std-workspace-std' }

Cargo.toml

@@ -9,7 +9,7 @@ std = { path = "../std" }
 # `core` when resolving doc links. Without this line a different `core` will be
 # loaded from sysroot causing duplicate lang items and other similar errors.
 core = { path = "../core" }
-rustc-literal-escaper = { version = "0.0.2", features = ["rustc-dep-of-std"] }
+rustc-literal-escaper = { version = "0.0.4", features = ["rustc-dep-of-std"] }
 
 [features]
 default = ["rustc-dep-of-std"]

proc_macro/Cargo.toml

@@ -56,7 +56,7 @@ use std::{error, fmt};
 pub use diagnostic::{Diagnostic, Level, MultiSpan};
 #[unstable(feature = "proc_macro_value", issue = "136652")]
 pub use rustc_literal_escaper::EscapeError;
-use rustc_literal_escaper::{MixedUnit, Mode, byte_from_char, unescape_mixed, unescape_unicode};
+use rustc_literal_escaper::{MixedUnit, unescape_byte_str, unescape_c_str, unescape_str};
 #[unstable(feature = "proc_macro_totokens", issue = "130977")]
 pub use to_tokens::ToTokens;
 
@@ -1440,10 +1440,9 @@ impl Literal {
                     // Force-inlining here is aggressive but the closure is
                     // called on every char in the string, so it can be hot in
                     // programs with many long strings containing escapes.
-                    unescape_unicode(
+                    unescape_str(
                         symbol,
-                        Mode::Str,
-                        &mut #[inline(always)]
+                        #[inline(always)]
                         |_, c| match c {
                             Ok(c) => buf.push(c),
                             Err(err) => {
@@ -1472,7 +1471,7 @@ impl Literal {
                 let mut error = None;
                 let mut buf = Vec::with_capacity(symbol.len());
 
-                unescape_mixed(symbol, Mode::CStr, &mut |_span, c| match c {
+                unescape_c_str(symbol, |_span, c| match c {
                     Ok(MixedUnit::Char(c)) => {
                         buf.extend_from_slice(c.encode_utf8(&mut [0; 4]).as_bytes())
                     }
@@ -1511,8 +1510,8 @@ impl Literal {
                 let mut buf = Vec::with_capacity(symbol.len());
                 let mut error = None;
 
-                unescape_unicode(symbol, Mode::ByteStr, &mut |_, c| match c {
-                    Ok(c) => buf.push(byte_from_char(c)),
+                unescape_byte_str(symbol, |_, res| match res {
+                    Ok(b) => buf.push(b),
                     Err(err) => {
                         if err.is_fatal() {
                             error = Some(ConversionErrorKind::FailedToUnescape(err));