From 2c7f2c105bb52d83409fc29bd181af442b8ba43d Mon Sep 17 00:00:00 2001
From: Nika Layzell <nika@thelayzells.com>
Date: Mon, 25 Jul 2022 00:43:33 -0400
Subject: [PATCH] proc_macro/bridge: send diagnostics over the bridge as a
 struct

This removes some RPC when creating and emitting diagnostics, and
simplifies the bridge slightly.

After this change, there are no remaining methods which take advantage
of the support for `&mut` references to objects in the store as
arguments, meaning that support for them could technically be removed if
we wanted. The only remaining uses of immutable references into the
store are `TokenStream` and `SourceFile`.
---
 .../src/abis/abi_sysroot/ra_server.rs         | 59 ++-----------------
 1 file changed, 4 insertions(+), 55 deletions(-)

diff --git a/crates/proc-macro-srv/src/abis/abi_sysroot/ra_server.rs b/crates/proc-macro-srv/src/abis/abi_sysroot/ra_server.rs
index 46882845a8..c1f8615aaf 100644
--- a/crates/proc-macro-srv/src/abis/abi_sysroot/ra_server.rs
+++ b/crates/proc-macro-srv/src/abis/abi_sysroot/ra_server.rs
@@ -37,23 +37,6 @@ pub struct SourceFile {
 type Level = super::proc_macro::Level;
 type LineColumn = super::proc_macro::LineColumn;
 
-/// A structure representing a diagnostic message and associated children
-/// messages.
-#[derive(Clone, Debug)]
-pub struct Diagnostic {
-    level: Level,
-    message: String,
-    spans: Vec<Span>,
-    children: Vec<Diagnostic>,
-}
-
-impl Diagnostic {
-    /// Creates a new diagnostic with the given `level` and `message`.
-    pub fn new<T: Into<String>>(level: Level, message: T) -> Diagnostic {
-        Diagnostic { level, message: message.into(), spans: vec![], children: vec![] }
-    }
-}
-
 pub struct FreeFunctions;
 
 #[derive(Default)]
@@ -65,8 +48,6 @@ impl server::Types for RustAnalyzer {
     type FreeFunctions = FreeFunctions;
     type TokenStream = TokenStream;
     type SourceFile = SourceFile;
-    type MultiSpan = Vec<Span>;
-    type Diagnostic = Diagnostic;
     type Span = Span;
     type Symbol = Symbol;
 }
@@ -90,6 +71,10 @@ impl server::FreeFunctions for RustAnalyzer {
             span: tt::TokenId::unspecified(),
         })
     }
+
+    fn emit_diagnostic(&mut self, _: bridge::Diagnostic<Self::Span>) {
+        // FIXME handle diagnostic
+    }
 }
 
 impl server::TokenStream for RustAnalyzer {
@@ -282,30 +267,6 @@ impl server::SourceFile for RustAnalyzer {
     }
 }
 
-impl server::Diagnostic for RustAnalyzer {
-    fn new(&mut self, level: Level, msg: &str, spans: Self::MultiSpan) -> Self::Diagnostic {
-        let mut diag = Diagnostic::new(level, msg);
-        diag.spans = spans;
-        diag
-    }
-
-    fn sub(
-        &mut self,
-        _diag: &mut Self::Diagnostic,
-        _level: Level,
-        _msg: &str,
-        _spans: Self::MultiSpan,
-    ) {
-        // FIXME handle diagnostic
-        //
-    }
-
-    fn emit(&mut self, _diag: Self::Diagnostic) {
-        // FIXME handle diagnostic
-        // diag.emit()
-    }
-}
-
 impl server::Span for RustAnalyzer {
     fn debug(&mut self, span: Self::Span) -> String {
         format!("{:?}", span.0)
@@ -372,18 +333,6 @@ impl server::Span for RustAnalyzer {
     }
 }
 
-impl server::MultiSpan for RustAnalyzer {
-    fn new(&mut self) -> Self::MultiSpan {
-        // FIXME handle span
-        vec![]
-    }
-
-    fn push(&mut self, other: &mut Self::MultiSpan, span: Self::Span) {
-        //TODP
-        other.push(span)
-    }
-}
-
 impl server::Symbol for RustAnalyzer {
     fn normalize_and_validate_ident(&mut self, string: &str) -> Result<Self::Symbol, ()> {
         // FIXME: nfc-normalize and validate idents