Use a dedicated type instead of a reference for the diagnostic context

This paves the way for tracking more state (e.g. error tainting) in the diagnostic context handle

Author: oli-obk

src/parse/macros/cfg_if.rs

@@ -67,7 +67,7 @@ fn parse_cfg_if_inner<'a>(
                 Ok(None) => continue,
                 Err(err) => {
                     err.cancel();
-                    parser.psess.dcx.reset_err_count();
+                    parser.psess.dcx().reset_err_count();
                     return Err(
                         "Expected item inside cfg_if block, but failed to parse it as an item",
                     );

src/parse/macros/lazy_static.rs

@@ -16,16 +16,16 @@ pub(crate) fn parse_lazy_static(
         ($method:ident $(,)* $($arg:expr),* $(,)*) => {
             match parser.$method($($arg,)*) {
                 Ok(val) => {
-                    if parser.psess.dcx.has_errors().is_some() {
-                        parser.psess.dcx.reset_err_count();
+                    if parser.psess.dcx().has_errors().is_some() {
+                        parser.psess.dcx().reset_err_count();
                         return None;
                     } else {
                         val
                     }
                 }
                 Err(err) => {
                     err.cancel();
-                    parser.psess.dcx.reset_err_count();
+                    parser.psess.dcx().reset_err_count();
                     return None;
                 }
             }

src/parse/macros/mod.rs

@@ -29,8 +29,8 @@ fn parse_macro_arg<'a, 'b: 'a>(parser: &'a mut Parser<'b>) -> Option<MacroArg> {
             if Parser::nonterminal_may_begin_with($nt_kind, &cloned_parser.token) {
                 match $try_parse(&mut cloned_parser) {
                     Ok(x) => {
-                        if parser.psess.dcx.has_errors().is_some() {
-                            parser.psess.dcx.reset_err_count();
+                        if parser.psess.dcx().has_errors().is_some() {
+                            parser.psess.dcx().reset_err_count();
                         } else {
                             // Parsing succeeded.
                             *parser = cloned_parser;
@@ -39,7 +39,7 @@ fn parse_macro_arg<'a, 'b: 'a>(parser: &'a mut Parser<'b>) -> Option<MacroArg> {
                     }
                     Err(e) => {
                         e.cancel();
-                        parser.psess.dcx.reset_err_count();
+                        parser.psess.dcx().reset_err_count();
                     }
                 }
             }

src/parse/session.rs

@@ -210,7 +210,9 @@ impl ParseSess {
             rustc_driver::DEFAULT_LOCALE_RESOURCES.to_vec(),
             false,
         );
-        self.raw_psess.dcx.make_silent(fallback_bundle, None, false);
+        self.raw_psess
+            .dcx()
+            .make_silent(fallback_bundle, None, false);
     }
 
     pub(crate) fn span_to_filename(&self, span: Span) -> FileName {
@@ -286,11 +288,11 @@ impl ParseSess {
     }
 
     pub(super) fn has_errors(&self) -> bool {
-        self.raw_psess.dcx.has_errors().is_some()
+        self.raw_psess.dcx().has_errors().is_some()
     }
 
     pub(super) fn reset_errors(&self) {
-        self.raw_psess.dcx.reset_err_count();
+        self.raw_psess.dcx().reset_err_count();
     }
 }