Auto merge of #30542 - nrc:errs-base, r=nagisa

As discussed [here](https://internals.rust-lang.org/t/more-structured-errors/3005)

r? @nikomatsakis or anyone else on the @rust-lang/compiler team

2 files changed, 47 insertions, 11 deletions

diff --git a/src/libsyntax/diagnostics/macros.rs b/src/libsyntax/diagnostics/macros.rs
index 3c8347f8a8e..95a74d87554 100644
--- a/src/libsyntax/diagnostics/macros.rs
+++ b/src/libsyntax/diagnostics/macros.rs
@@ -31,6 +31,14 @@ macro_rules! span_err {
 }
 
 #[macro_export]
+macro_rules! span_warn {
+    ($session:expr, $span:expr, $code:ident, $($message:tt)*) => ({
+        __diagnostic_used!($code);
+        $session.span_warn_with_code($span, &format!($($message)*), stringify!($code))
+    })
+}
+
+#[macro_export]
 macro_rules! span_err_or_warn {
     ($is_warning:expr, $session:expr, $span:expr, $code:ident, $($message:tt)*) => ({
         __diagnostic_used!($code);
@@ -43,31 +51,59 @@ macro_rules! span_err_or_warn {
 }
 
 #[macro_export]
-macro_rules! span_warn {
+macro_rules! struct_span_fatal {
     ($session:expr, $span:expr, $code:ident, $($message:tt)*) => ({
         __diagnostic_used!($code);
-        $session.span_warn_with_code($span, &format!($($message)*), stringify!($code))
+        $session.struct_span_fatal_with_code($span, &format!($($message)*), stringify!($code))
+    })
+}
+
+#[macro_export]
+macro_rules! struct_span_err {
+    ($session:expr, $span:expr, $code:ident, $($message:tt)*) => ({
+        __diagnostic_used!($code);
+        $session.struct_span_err_with_code($span, &format!($($message)*), stringify!($code))
+    })
+}
+
+#[macro_export]
+macro_rules! struct_span_warn {
+    ($session:expr, $span:expr, $code:ident, $($message:tt)*) => ({
+        __diagnostic_used!($code);
+        $session.struct_span_warn_with_code($span, &format!($($message)*), stringify!($code))
+    })
+}
+
+#[macro_export]
+macro_rules! struct_span_err_or_warn {
+    ($is_warning:expr, $session:expr, $span:expr, $code:ident, $($message:tt)*) => ({
+        __diagnostic_used!($code);
+        if $is_warning {
+            $session.struct_span_warn_with_code($span, &format!($($message)*), stringify!($code))
+        } else {
+            $session.struct_span_err_with_code($span, &format!($($message)*), stringify!($code))
+        }
     })
 }
 
 #[macro_export]
 macro_rules! span_note {
-    ($session:expr, $span:expr, $($message:tt)*) => ({
-        ($session).span_note($span, &format!($($message)*))
+    ($err:expr, $span:expr, $($message:tt)*) => ({
+        ($err).span_note($span, &format!($($message)*));
     })
 }
 
 #[macro_export]
 macro_rules! span_help {
-    ($session:expr, $span:expr, $($message:tt)*) => ({
-        ($session).span_help($span, &format!($($message)*))
+    ($err:expr, $span:expr, $($message:tt)*) => ({
+        ($err).span_help($span, &format!($($message)*));
     })
 }
 
 #[macro_export]
 macro_rules! fileline_help {
-    ($session:expr, $span:expr, $($message:tt)*) => ({
-        ($session).fileline_help($span, &format!($($message)*))
+    ($err:expr, $span:expr, $($message:tt)*) => ({
+        ($err).fileline_help($span, &format!($($message)*));
     })
 }
 
diff --git a/src/libsyntax/diagnostics/plugin.rs b/src/libsyntax/diagnostics/plugin.rs
index be0d5729c70..d17ca3892dc 100644
--- a/src/libsyntax/diagnostics/plugin.rs
+++ b/src/libsyntax/diagnostics/plugin.rs
@@ -62,10 +62,10 @@ pub fn expand_diagnostic_used<'cx>(ecx: &'cx mut ExtCtxt,
         match diagnostics.get_mut(&code.name) {
             // Previously used errors.
             Some(&mut ErrorInfo { description: _, use_site: Some(previous_span) }) => {
-                ecx.span_warn(span, &format!(
+                ecx.struct_span_warn(span, &format!(
                     "diagnostic code {} already used", code
-                ));
-                ecx.span_note(previous_span, "previous invocation");
+                )).span_note(previous_span, "previous invocation")
+                  .emit();
             }
             // Newly used errors.
             Some(ref mut info) => {