Auto merge of #55462 - pietroalbini:rollup, r=pietroalbini

Rollup of 9 pull requests

Successful merges:

 - #54965 (update tcp stream documentation)
 - #55269 (fix typos in various places)
 - #55384 (Avoid unnecessary allocations in `float_lit` and `integer_lit`.)
 - #55423 (back out bogus `Ok`-wrapping suggestion on `?` arm type mismatch)
 - #55426 (Make a bunch of trivial methods of NonNull be `#[inline]`)
 - #55438 (Avoid directly catching BaseException in bootstrap configure script)
 - #55439 (Remove unused sys import from generate-deriving-span-tests)
 - #55440 (Remove unreachable code in hasClass function in Rustdoc)
 - #55447 (Fix invalid path in generate-deriving-span-tests.py.)

Failed merges:

r? @ghost

1 files changed, 19 insertions, 4 deletions

diff --git a/src/libsyntax/parse/mod.rs b/src/libsyntax/parse/mod.rs
index a4b8ab86f37..77a2ae6acf0 100644
--- a/src/libsyntax/parse/mod.rs
+++ b/src/libsyntax/parse/mod.rs
@@ -494,8 +494,17 @@ fn float_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
                  -> Option<ast::LitKind> {
     debug!("float_lit: {:?}, {:?}", s, suffix);
     // FIXME #2252: bounds checking float literals is deferred until trans
-    let s = s.chars().filter(|&c| c != '_').collect::<String>();
-    filtered_float_lit(Symbol::intern(&s), suffix, diag)
+
+    // Strip underscores without allocating a new String unless necessary.
+    let s2;
+    let s = if s.chars().any(|c| c == '_') {
+        s2 = s.chars().filter(|&c| c != '_').collect::<String>();
+        &s2
+    } else {
+        s
+    };
+
+    filtered_float_lit(Symbol::intern(s), suffix, diag)
 }
 
 /// Parse a string representing a byte literal into its final form. Similar to `char_lit`
@@ -591,8 +600,14 @@ fn integer_lit(s: &str, suffix: Option<Symbol>, diag: Option<(Span, &Handler)>)
                    -> Option<ast::LitKind> {
     // s can only be ascii, byte indexing is fine
 
-    let s2 = s.chars().filter(|&c| c != '_').collect::<String>();
-    let mut s = &s2[..];
+    // Strip underscores without allocating a new String unless necessary.
+    let s2;
+    let mut s = if s.chars().any(|c| c == '_') {
+        s2 = s.chars().filter(|&c| c != '_').collect::<String>();
+        &s2
+    } else {
+        s
+    };
 
     debug!("integer_lit: {}, {:?}", s, suffix);