From 205fb75cfa3339fcbac70e8da9c381060a8940cc Mon Sep 17 00:00:00 2001
From: Vadim Petrochenkov <vadim.petrochenkov@gmail.com>
Date: Fri, 5 Jan 2024 17:11:25 +0300
Subject: [PATCH] rustc_span: Remove `fn fresh_expansion`

In the past it did create a fresh expansion, but now, after surviving a number of refactorings, it does not.
Now it's just a thin wrapper around `apply_mark`.
---
 compiler/rustc_span/src/hygiene.rs              | 17 +----------------
 .../passes/lint/check_code_block_syntax.rs      |  4 ++--
 2 files changed, 3 insertions(+), 18 deletions(-)

diff --git a/compiler/rustc_span/src/hygiene.rs b/compiler/rustc_span/src/hygiene.rs
index b717229b68d..fec05e8e0b3 100644
--- a/compiler/rustc_span/src/hygiene.rs
+++ b/compiler/rustc_span/src/hygiene.rs
@@ -850,21 +850,6 @@ impl fmt::Debug for SyntaxContext {
 }
 
 impl Span {
-    /// Creates a fresh expansion with given properties.
-    /// Expansions are normally created by macros, but in some cases expansions are created for
-    /// other compiler-generated code to set per-span properties like allowed unstable features.
-    /// The returned span belongs to the created expansion and has the new properties,
-    /// but its location is inherited from the current span.
-    pub fn fresh_expansion(self, expn_id: LocalExpnId) -> Span {
-        HygieneData::with(|data| {
-            self.with_ctxt(data.apply_mark(
-                self.ctxt(),
-                expn_id.to_expn_id(),
-                Transparency::Transparent,
-            ))
-        })
-    }
-
     /// Reuses the span but adds information like the kind of the desugaring and features that are
     /// allowed inside this span.
     pub fn mark_with_reason(
@@ -879,7 +864,7 @@ impl Span {
             ..ExpnData::default(ExpnKind::Desugaring(reason), self, edition, None, None)
         };
         let expn_id = LocalExpnId::fresh(expn_data, ctx);
-        self.fresh_expansion(expn_id)
+        self.apply_mark(expn_id.to_expn_id(), Transparency::Transparent)
     }
 }
 
diff --git a/src/librustdoc/passes/lint/check_code_block_syntax.rs b/src/librustdoc/passes/lint/check_code_block_syntax.rs
index 53c7f0f6e15..782938f1094 100644
--- a/src/librustdoc/passes/lint/check_code_block_syntax.rs
+++ b/src/librustdoc/passes/lint/check_code_block_syntax.rs
@@ -8,7 +8,7 @@ use rustc_errors::{
 use rustc_parse::parse_stream_from_source_str;
 use rustc_resolve::rustdoc::source_span_for_markdown_range;
 use rustc_session::parse::ParseSess;
-use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId};
+use rustc_span::hygiene::{AstPass, ExpnData, ExpnKind, LocalExpnId, Transparency};
 use rustc_span::source_map::{FilePathMapping, SourceMap};
 use rustc_span::{FileName, InnerSpan, DUMMY_SP};
 
@@ -50,7 +50,7 @@ fn check_rust_syntax(
     let expn_data =
         ExpnData::default(ExpnKind::AstPass(AstPass::TestHarness), DUMMY_SP, edition, None, None);
     let expn_id = cx.tcx.with_stable_hashing_context(|hcx| LocalExpnId::fresh(expn_data, hcx));
-    let span = DUMMY_SP.fresh_expansion(expn_id);
+    let span = DUMMY_SP.apply_mark(expn_id.to_expn_id(), Transparency::Transparent);
 
     let is_empty = rustc_driver::catch_fatal_errors(|| {
         parse_stream_from_source_str(