Rollup merge of #84961 - GuillaumeGomez:rework-session-globals, r=oli-obk

Rework SESSION_GLOBALS API

Fixes #84954.

<s>Needs #84953 to be merged first (I cherry-picked its commits to have CI pass).</s> (done)

r? ``@Aaron1011``

9 files changed, 28 insertions, 23 deletions

diff --git a/src/librustdoc/clean/cfg/tests.rs b/src/librustdoc/clean/cfg/tests.rs
index 34b9cbcb679..275d1b3ebd9 100644
--- a/src/librustdoc/clean/cfg/tests.rs
+++ b/src/librustdoc/clean/cfg/tests.rs
@@ -2,8 +2,8 @@ use super::*;
 
 use rustc_ast::attr;
 use rustc_ast::Path;
+use rustc_span::create_default_session_globals_then;
 use rustc_span::symbol::{Ident, Symbol};
-use rustc_span::with_default_session_globals;
 use rustc_span::DUMMY_SP;
 
 fn word_cfg(s: &str) -> Cfg {
@@ -52,7 +52,7 @@ macro_rules! dummy_meta_item_list {
 
 #[test]
 fn test_cfg_not() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         assert_eq!(!Cfg::False, Cfg::True);
         assert_eq!(!Cfg::True, Cfg::False);
         assert_eq!(!word_cfg("test"), Cfg::Not(Box::new(word_cfg("test"))));
@@ -70,7 +70,7 @@ fn test_cfg_not() {
 
 #[test]
 fn test_cfg_and() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         let mut x = Cfg::False;
         x &= Cfg::True;
         assert_eq!(x, Cfg::False);
@@ -154,7 +154,7 @@ fn test_cfg_and() {
 
 #[test]
 fn test_cfg_or() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         let mut x = Cfg::True;
         x |= Cfg::False;
         assert_eq!(x, Cfg::True);
@@ -238,7 +238,7 @@ fn test_cfg_or() {
 
 #[test]
 fn test_parse_ok() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         let mi = dummy_meta_item_word("all");
         assert_eq!(Cfg::parse(&mi), Ok(word_cfg("all")));
 
@@ -271,7 +271,7 @@ fn test_parse_ok() {
 
 #[test]
 fn test_parse_err() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         let mi = attr::mk_name_value_item(Ident::from_str("foo"), LitKind::Bool(false), DUMMY_SP);
         assert!(Cfg::parse(&mi).is_err());
 
@@ -303,7 +303,7 @@ fn test_parse_err() {
 
 #[test]
 fn test_render_short_html() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         assert_eq!(word_cfg("unix").render_short_html(), "Unix");
         assert_eq!(name_value_cfg("target_os", "macos").render_short_html(), "macOS");
         assert_eq!(name_value_cfg("target_pointer_width", "16").render_short_html(), "16-bit");
@@ -358,7 +358,7 @@ fn test_render_short_html() {
 
 #[test]
 fn test_render_long_html() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         assert_eq!(
             word_cfg("unix").render_long_html(),
             "This is supported on <strong>Unix</strong> only."
@@ -442,7 +442,7 @@ fn test_render_long_html() {
 fn test_simplify_with() {
     // This is a tiny subset of things that could be simplified, but it likely covers 90% of
     // real world usecases well.
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         let foo = word_cfg("foo");
         let bar = word_cfg("bar");
         let baz = word_cfg("baz");
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index 1281f76fd0f..cd914f05e68 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -513,7 +513,7 @@ crate fn make_test(
     // Uses librustc_ast to parse the doctest and find if there's a main fn and the extern
     // crate already is included.
     let result = rustc_driver::catch_fatal_errors(|| {
-        rustc_span::with_session_globals(edition, || {
+        rustc_span::create_session_if_not_set_then(edition, |_| {
             use rustc_errors::emitter::{Emitter, EmitterWriter};
             use rustc_errors::Handler;
             use rustc_parse::maybe_new_parser_from_source_str;
diff --git a/src/librustdoc/html/highlight/tests.rs b/src/librustdoc/html/highlight/tests.rs
index a0da2c963d1..a505865b149 100644
--- a/src/librustdoc/html/highlight/tests.rs
+++ b/src/librustdoc/html/highlight/tests.rs
@@ -1,8 +1,8 @@
 use super::write_code;
 use crate::html::format::Buffer;
 use expect_test::expect_file;
+use rustc_span::create_default_session_globals_then;
 use rustc_span::edition::Edition;
-use rustc_span::with_default_session_globals;
 
 const STYLE: &str = r#"
 <style>
@@ -18,7 +18,7 @@ const STYLE: &str = r#"
 
 #[test]
 fn test_html_highlighting() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         let src = include_str!("fixtures/sample.rs");
         let html = {
             let mut out = Buffer::new();
@@ -31,7 +31,7 @@ fn test_html_highlighting() {
 
 #[test]
 fn test_dos_backline() {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         let src = "pub fn foo() {\r\n\
     println!(\"foo\");\r\n\
 }\r\n";
diff --git a/src/librustdoc/passes/unindent_comments/tests.rs b/src/librustdoc/passes/unindent_comments/tests.rs
index 9c9924841b9..82d1afac5ec 100644
--- a/src/librustdoc/passes/unindent_comments/tests.rs
+++ b/src/librustdoc/passes/unindent_comments/tests.rs
@@ -1,7 +1,7 @@
 use super::*;
+use rustc_span::create_default_session_globals_then;
 use rustc_span::source_map::DUMMY_SP;
 use rustc_span::symbol::Symbol;
-use rustc_span::with_default_session_globals;
 
 fn create_doc_fragment(s: &str) -> Vec<DocFragment> {
     vec![DocFragment {
@@ -17,7 +17,7 @@ fn create_doc_fragment(s: &str) -> Vec<DocFragment> {
 
 #[track_caller]
 fn run_test(input: &str, expected: &str) {
-    with_default_session_globals(|| {
+    create_default_session_globals_then(|| {
         let mut s = create_doc_fragment(input);
         unindent_fragments(&mut s);
         assert_eq!(&s.iter().collect::<String>(), expected);
diff --git a/src/test/ui-fulldeps/mod_dir_path_canonicalized.rs b/src/test/ui-fulldeps/mod_dir_path_canonicalized.rs
index 448c57da754..bb246de0e57 100644
--- a/src/test/ui-fulldeps/mod_dir_path_canonicalized.rs
+++ b/src/test/ui-fulldeps/mod_dir_path_canonicalized.rs
@@ -19,7 +19,7 @@ use std::path::Path;
 mod gravy;
 
 pub fn main() {
-    rustc_span::with_default_session_globals(|| parse());
+    rustc_span::create_default_session_globals_then(|| parse());
 
     assert_eq!(gravy::foo(), 10);
 }
diff --git a/src/test/ui-fulldeps/pprust-expr-roundtrip.rs b/src/test/ui-fulldeps/pprust-expr-roundtrip.rs
index 091c834eccf..36ff8b01fd4 100644
--- a/src/test/ui-fulldeps/pprust-expr-roundtrip.rs
+++ b/src/test/ui-fulldeps/pprust-expr-roundtrip.rs
@@ -202,7 +202,7 @@ impl MutVisitor for AddParens {
 }
 
 fn main() {
-    rustc_span::with_default_session_globals(|| run());
+    rustc_span::create_default_session_globals_then(|| run());
 }
 
 fn run() {
diff --git a/src/tools/clippy/clippy_lints/src/doc.rs b/src/tools/clippy/clippy_lints/src/doc.rs
index 4e164d33a05..d6e3e92fc5e 100644
--- a/src/tools/clippy/clippy_lints/src/doc.rs
+++ b/src/tools/clippy/clippy_lints/src/doc.rs
@@ -26,6 +26,7 @@ use rustc_span::source_map::{BytePos, FilePathMapping, MultiSpan, SourceMap, Spa
 use rustc_span::{sym, FileName, Pos};
 use std::io;
 use std::ops::Range;
+use std::thread;
 use url::Url;
 
 declare_clippy_lint! {
@@ -584,10 +585,10 @@ fn get_current_span(spans: &[(usize, Span)], idx: usize) -> (usize, Span) {
 }
 
 fn check_code(cx: &LateContext<'_>, text: &str, edition: Edition, span: Span) {
-    fn has_needless_main(code: &str, edition: Edition) -> bool {
+    fn has_needless_main(code: String, edition: Edition) -> bool {
         rustc_driver::catch_fatal_errors(|| {
-            rustc_span::with_session_globals(edition, || {
-                let filename = FileName::anon_source_code(code);
+            rustc_span::create_session_globals_then(edition, || {
+                let filename = FileName::anon_source_code(&code);
 
                 let sm = Lrc::new(SourceMap::new(FilePathMapping::empty()));
                 let emitter = EmitterWriter::new(box io::sink(), None, false, false, false, None, false);
@@ -649,7 +650,10 @@ fn check_code(cx: &LateContext<'_>, text: &str, edition: Edition, span: Span) {
         .unwrap_or_default()
     }
 
-    if has_needless_main(text, edition) {
+    // Because of the global session, we need to create a new session in a different thread with
+    // the edition we need.
+    let text = text.to_owned();
+    if thread::spawn(move || has_needless_main(text, edition)).join().expect("thread::spawn failed") {
         span_lint(cx, NEEDLESS_DOCTEST_MAIN, span, "needless `fn main` in doctest");
     }
 }
diff --git a/src/tools/error_index_generator/main.rs b/src/tools/error_index_generator/main.rs
index e3700136aca..01a3fc812b2 100644
--- a/src/tools/error_index_generator/main.rs
+++ b/src/tools/error_index_generator/main.rs
@@ -284,7 +284,8 @@ fn parse_args() -> (OutputFormat, PathBuf) {
 fn main() {
     rustc_driver::init_env_logger("RUST_LOG");
     let (format, dst) = parse_args();
-    let result = rustc_span::with_default_session_globals(move || main_with_result(format, &dst));
+    let result =
+        rustc_span::create_default_session_globals_then(move || main_with_result(format, &dst));
     if let Err(e) = result {
         panic!("{}", e.to_string());
     }
diff --git a/src/tools/rustfmt/src/formatting.rs b/src/tools/rustfmt/src/formatting.rs
index b69ecdc5cb8..e0403574eeb 100644
--- a/src/tools/rustfmt/src/formatting.rs
+++ b/src/tools/rustfmt/src/formatting.rs
@@ -34,7 +34,7 @@ impl<'b, T: Write + 'b> Session<'b, T> {
             return Err(ErrorKind::VersionMismatch);
         }
 
-        rustc_span::with_session_globals(self.config.edition().into(), || {
+        rustc_span::create_session_if_not_set_then(self.config.edition().into(), |_| {
             if self.config.disable_all_formatting() {
                 // When the input is from stdin, echo back the input.
                 if let Input::Text(ref buf) = input {