Dogfood trim_{suffix|prefix} in compiler

compiler/rustc_codegen_llvm/src/back/write.rs

@@ -451,7 +451,7 @@ fn report_inline_asm(
         llvm::DiagnosticLevel::Warning => Level::Warning,
         llvm::DiagnosticLevel::Note | llvm::DiagnosticLevel::Remark => Level::Note,
     };
-    let msg = msg.strip_prefix("error: ").unwrap_or(&msg).to_string();
+    let msg = msg.trim_prefix("error: ").to_string();
     cgcx.diag_emitter.inline_asm_error(span, msg, level, source);
 }
 

compiler/rustc_codegen_llvm/src/lib.rs

@@ -17,6 +17,7 @@
 #![feature(macro_derive)]
 #![feature(rustdoc_internals)]
 #![feature(slice_as_array)]
+#![feature(trim_prefix_suffix)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end
 

compiler/rustc_driver_impl/src/lib.rs

@@ -13,6 +13,7 @@
 #![feature(panic_backtrace_config)]
 #![feature(panic_update_hook)]
 #![feature(rustdoc_internals)]
+#![feature(trim_prefix_suffix)]
 #![feature(try_blocks)]
 // tidy-alphabetical-end
 
@@ -466,7 +467,7 @@ pub enum Compilation {
 fn handle_explain(early_dcx: &EarlyDiagCtxt, registry: Registry, code: &str, color: ColorConfig) {
     // Allow "E0123" or "0123" form.
     let upper_cased_code = code.to_ascii_uppercase();
-    if let Ok(code) = upper_cased_code.strip_prefix('E').unwrap_or(&upper_cased_code).parse::<u32>()
+    if let Ok(code) = upper_cased_code.trim_prefix('E').parse::<u32>()
         && code <= ErrCode::MAX_AS_U32
         && let Ok(description) = registry.try_find_description(ErrCode::from_u32(code))
     {
@@ -1263,7 +1264,7 @@ fn warn_on_confusing_output_filename_flag(
     if let Some(name) = matches.opt_str("o")
         && let Some(suspect) = args.iter().find(|arg| arg.starts_with("-o") && *arg != "-o")
     {
-        let filename = suspect.strip_prefix("-").unwrap_or(suspect);
+        let filename = suspect.trim_prefix("-");
         let optgroups = config::rustc_optgroups();
         let fake_args = ["optimize", "o0", "o1", "o2", "o3", "ofast", "og", "os", "oz"];
 

compiler/rustc_hir_typeck/src/lib.rs

@@ -7,6 +7,7 @@
 #![feature(iter_intersperse)]
 #![feature(iter_order_by)]
 #![feature(never_type)]
+#![feature(trim_prefix_suffix)]
 // tidy-alphabetical-end
 
 mod _match;

compiler/rustc_hir_typeck/src/method/suggest.rs

@@ -2551,7 +2551,7 @@ impl<'a, 'tcx> FnCtxt<'a, 'tcx> {
 
                     // If this is a floating point literal that ends with '.',
                     // get rid of it to stop this from becoming a member access.
-                    let snippet = snippet.strip_suffix('.').unwrap_or(&snippet);
+                    let snippet = snippet.trim_suffix('.');
                     err.span_suggestion(
                         lit.span,
                         format!(

compiler/rustc_resolve/src/late/diagnostics.rs

@@ -2608,7 +2608,7 @@ impl<'ast, 'ra, 'tcx> LateResolutionVisitor<'_, 'ast, 'ra, 'tcx> {
             let (span, text) = match path.segments.first() {
                 Some(seg) if let Some(name) = seg.ident.as_str().strip_prefix("let") => {
                     // a special case for #117894
-                    let name = name.strip_prefix('_').unwrap_or(name);
+                    let name = name.trim_prefix('_');
                     (ident_span, format!("let {name}"))
                 }
                 _ => (ident_span.shrink_to_lo(), "let ".to_string()),

compiler/rustc_resolve/src/lib.rs

@@ -22,6 +22,7 @@
 #![feature(ptr_as_ref_unchecked)]
 #![feature(rustc_attrs)]
 #![feature(rustdoc_internals)]
+#![feature(trim_prefix_suffix)]
 #![recursion_limit = "256"]
 // tidy-alphabetical-end
 

compiler/rustc_resolve/src/rustdoc.rs

@@ -400,10 +400,10 @@ fn preprocess_link(link: &str) -> Box<str> {
     let link = link.split('#').next().unwrap();
     let link = link.trim();
     let link = link.rsplit('@').next().unwrap();
-    let link = link.strip_suffix("()").unwrap_or(link);
-    let link = link.strip_suffix("{}").unwrap_or(link);
-    let link = link.strip_suffix("[]").unwrap_or(link);
-    let link = if link != "!" { link.strip_suffix('!').unwrap_or(link) } else { link };
+    let link = link.trim_suffix("()");
+    let link = link.trim_suffix("{}");
+    let link = link.trim_suffix("[]");
+    let link = if link != "!" { link.trim_suffix('!') } else { link };
     let link = link.trim();
     strip_generics_from_path(link).unwrap_or_else(|_| link.into())
 }

src/librustdoc/html/markdown.rs

@@ -264,9 +264,7 @@ impl<'a, I: Iterator<Item = Event<'a>>> Iterator for CodeBlocks<'_, 'a, I> {
                                  </pre>\
                              </div>",
                                 added_classes = added_classes.join(" "),
-                                text = Escape(
-                                    original_text.strip_suffix('\n').unwrap_or(&original_text)
-                                ),
+                                text = Escape(original_text.trim_suffix('\n')),
                             )
                             .into(),
                         ));

src/librustdoc/html/sources.rs

@@ -185,7 +185,7 @@ impl SourceCollector<'_, '_> {
         };
 
         // Remove the utf-8 BOM if any
-        let contents = contents.strip_prefix('\u{feff}').unwrap_or(&contents);
+        let contents = contents.trim_prefix('\u{feff}');
 
         let shared = &self.cx.shared;
         // Create the intermediate directories

src/librustdoc/lib.rs

@@ -17,6 +17,7 @@
 #![feature(iter_order_by)]
 #![feature(rustc_private)]
 #![feature(test)]
+#![feature(trim_prefix_suffix)]
 #![warn(rustc::internal)]
 // tidy-alphabetical-end