Delay parsing of `--cfg` and `--check-cfg` options.

By storing the unparsed values in `Config` and then parsing them within
`run_compiler`, the parsing functions can use the main symbol interner,
and not create their own short-lived interners.

This change also eliminates the need for one `EarlyErrorHandler` in
rustdoc, because parsing errors can be reported by another, slightly
later `EarlyErrorHandler`.

3 files changed, 8 insertions, 15 deletions

diff --git a/src/librustdoc/core.rs b/src/librustdoc/core.rs
index bcc61df7c4d..17b117de5d4 100644
--- a/src/librustdoc/core.rs
+++ b/src/librustdoc/core.rs
@@ -14,8 +14,8 @@ use rustc_lint::{late_lint_mod, MissingDoc};
 use rustc_middle::hir::nested_filter;
 use rustc_middle::ty::{ParamEnv, Ty, TyCtxt};
 use rustc_session::config::{self, CrateType, ErrorOutputType, ResolveDocLinks};
+use rustc_session::lint;
 use rustc_session::Session;
-use rustc_session::{lint, EarlyErrorHandler};
 use rustc_span::symbol::sym;
 use rustc_span::{source_map, Span};
 
@@ -175,7 +175,6 @@ pub(crate) fn new_handler(
 
 /// Parse, resolve, and typecheck the given crate.
 pub(crate) fn create_config(
-    handler: &EarlyErrorHandler,
     RustdocOptions {
         input,
         crate_name,
@@ -255,8 +254,8 @@ pub(crate) fn create_config(
 
     interface::Config {
         opts: sessopts,
-        crate_cfg: interface::parse_cfg(handler, cfgs),
-        crate_check_cfg: interface::parse_check_cfg(handler, check_cfgs),
+        crate_cfg: cfgs,
+        crate_check_cfg: check_cfgs,
         input,
         output_file: None,
         output_dir: None,
diff --git a/src/librustdoc/doctest.rs b/src/librustdoc/doctest.rs
index c61c98e4de9..2412865801d 100644
--- a/src/librustdoc/doctest.rs
+++ b/src/librustdoc/doctest.rs
@@ -13,7 +13,7 @@ use rustc_parse::parser::attr::InnerAttrPolicy;
 use rustc_resolve::rustdoc::span_of_fragments;
 use rustc_session::config::{self, CrateType, ErrorOutputType};
 use rustc_session::parse::ParseSess;
-use rustc_session::{lint, EarlyErrorHandler, Session};
+use rustc_session::{lint, Session};
 use rustc_span::edition::Edition;
 use rustc_span::source_map::SourceMap;
 use rustc_span::symbol::sym;
@@ -85,18 +85,13 @@ pub(crate) fn run(options: RustdocOptions) -> Result<(), ErrorGuaranteed> {
         ..config::Options::default()
     };
 
-    let early_error_handler = EarlyErrorHandler::new(ErrorOutputType::default());
-
     let mut cfgs = options.cfgs.clone();
     cfgs.push("doc".to_owned());
     cfgs.push("doctest".to_owned());
     let config = interface::Config {
         opts: sessopts,
-        crate_cfg: interface::parse_cfg(&early_error_handler, cfgs),
-        crate_check_cfg: interface::parse_check_cfg(
-            &early_error_handler,
-            options.check_cfgs.clone(),
-        ),
+        crate_cfg: cfgs,
+        crate_check_cfg: options.check_cfgs.clone(),
         input,
         output_file: None,
         output_dir: None,
diff --git a/src/librustdoc/lib.rs b/src/librustdoc/lib.rs
index 41aee06c8d2..dda06d4c9c1 100644
--- a/src/librustdoc/lib.rs
+++ b/src/librustdoc/lib.rs
@@ -757,8 +757,7 @@ fn main_args(
         (false, true) => {
             let input = options.input.clone();
             let edition = options.edition;
-            let config =
-                core::create_config(handler, options, &render_options, using_internal_features);
+            let config = core::create_config(options, &render_options, using_internal_features);
 
             // `markdown::render` can invoke `doctest::make_test`, which
             // requires session globals and a thread pool, so we use
@@ -791,7 +790,7 @@ fn main_args(
     let scrape_examples_options = options.scrape_examples_options.clone();
     let bin_crate = options.bin_crate;
 
-    let config = core::create_config(handler, options, &render_options, using_internal_features);
+    let config = core::create_config(options, &render_options, using_internal_features);
 
     interface::run_compiler(config, |compiler| {
         let sess = compiler.session();