Rename kw::Invalid -> kw::Empty

See https://rust-lang.zulipchat.com/#narrow/stream/182449-t-compiler.2Fhelp/topic/Is.20there.20a.20symbol.20for.20the.20empty.20string.3F/near/220054471
for context.

Author: jyn514

compiler/rustc_ast_lowering/src/lib.rs

@@ -1716,7 +1716,7 @@ impl<'a, 'hir> LoweringContext<'a, 'hir> {
         }
         self.arena.alloc_from_iter(inputs.iter().map(|param| match param.pat.kind {
             PatKind::Ident(_, ident, _) => ident,
-            _ => Ident::new(kw::Invalid, param.pat.span),
+            _ => Ident::new(kw::Empty, param.pat.span),
         }))
     }
 

compiler/rustc_ast_passes/src/ast_validation.rs

@@ -184,7 +184,7 @@ impl<'a> AstValidator<'a> {
     }
 
     fn check_lifetime(&self, ident: Ident) {
-        let valid_names = [kw::UnderscoreLifetime, kw::StaticLifetime, kw::Invalid];
+        let valid_names = [kw::UnderscoreLifetime, kw::StaticLifetime, kw::Empty];
         if !valid_names.contains(&ident.name) && ident.without_first_quote().is_reserved() {
             self.err_handler().span_err(ident.span, "lifetimes cannot use keyword names");
         }

compiler/rustc_ast_pretty/src/pprust/state.rs

@@ -2787,7 +2787,7 @@ impl<'a> State<'a> {
                     self.print_explicit_self(&eself);
                 } else {
                     let invalid = if let PatKind::Ident(_, ident, _) = input.pat.kind {
-                        ident.name == kw::Invalid
+                        ident.name == kw::Empty
                     } else {
                         false
                     };

compiler/rustc_builtin_macros/src/llvm_asm.rs

@@ -93,7 +93,7 @@ fn parse_inline_asm<'a>(
         })
         .unwrap_or(tts.len());
     let mut p = cx.new_parser_from_tts(tts.trees().skip(first_colon).collect());
-    let mut asm = kw::Invalid;
+    let mut asm = kw::Empty;
     let mut asm_str_style = None;
     let mut outputs = Vec::new();
     let mut inputs = Vec::new();

compiler/rustc_codegen_ssa/src/mir/debuginfo.rs

@@ -170,7 +170,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
                 // (after #67586 gets fixed).
                 None
             } else {
-                let name = kw::Invalid;
+                let name = kw::Empty;
                 let decl = &self.mir.local_decls[local];
                 let dbg_var = if full_debug_info {
                     self.adjusted_span_and_dbg_scope(decl.source_info).map(
@@ -204,7 +204,7 @@ impl<'a, 'tcx, Bx: BuilderMethods<'a, 'tcx>> FunctionCx<'a, 'tcx, Bx> {
             None
         } else {
             Some(match whole_local_var.or(fallback_var) {
-                Some(var) if var.name != kw::Invalid => var.name.to_string(),
+                Some(var) if var.name != kw::Empty => var.name.to_string(),
                 _ => format!("{:?}", local),
             })
         };

compiler/rustc_hir/src/hir.rs

@@ -28,7 +28,7 @@ pub struct Lifetime {
     pub span: Span,
 
     /// Either "`'a`", referring to a named lifetime definition,
-    /// or "``" (i.e., `kw::Invalid`), for elision placeholders.
+    /// or "``" (i.e., `kw::Empty`), for elision placeholders.
     ///
     /// HIR lowering inserts these placeholders in type paths that
     /// refer to type definitions needing lifetime parameters,

compiler/rustc_lint/src/builtin.rs

@@ -868,7 +868,7 @@ impl EarlyLintPass for AnonymousParameters {
         if let ast::AssocItemKind::Fn(_, ref sig, _, _) = it.kind {
             for arg in sig.decl.inputs.iter() {
                 if let ast::PatKind::Ident(_, ident, None) = arg.pat.kind {
-                    if ident.name == kw::Invalid {
+                    if ident.name == kw::Empty {
                         cx.struct_span_lint(ANONYMOUS_PARAMETERS, arg.pat.span, |lint| {
                             let ty_snip = cx.sess.source_map().span_to_snippet(arg.ty.span);
 

compiler/rustc_lint/src/context.rs

@@ -728,7 +728,7 @@ impl<'tcx> LateContext<'tcx> {
 
     /// Check if a `DefId`'s path matches the given absolute type path usage.
     ///
-    /// Anonymous scopes such as `extern` imports are matched with `kw::Invalid`;
+    /// Anonymous scopes such as `extern` imports are matched with `kw::Empty`;
     /// inherent `impl` blocks are matched with the name of the type.
     ///
     /// Instead of using this method, it is often preferable to instead use

compiler/rustc_metadata/src/native_libs.rs

@@ -132,7 +132,7 @@ impl ItemLikeVisitor<'tcx> for Collector<'tcx> {
 
 impl Collector<'tcx> {
     fn register_native_lib(&mut self, span: Option<Span>, lib: NativeLib) {
-        if lib.name.as_ref().map(|&s| s == kw::Invalid).unwrap_or(false) {
+        if lib.name.as_ref().map(|&s| s == kw::Empty).unwrap_or(false) {
             match span {
                 Some(span) => {
                     struct_span_err!(

compiler/rustc_middle/src/hir/map/mod.rs

@@ -379,7 +379,7 @@ impl<'hir> Map<'hir> {
     pub fn body_param_names(&self, id: BodyId) -> impl Iterator<Item = Ident> + 'hir {
         self.body(id).params.iter().map(|arg| match arg.pat.kind {
             PatKind::Binding(_, _, ident, _) => ident,
-            _ => Ident::new(kw::Invalid, rustc_span::DUMMY_SP),
+            _ => Ident::new(kw::Empty, rustc_span::DUMMY_SP),
         })
     }