add check.ignore to list cargo check diagnostics to ignore (dead_code, unused_imports, ...)

fixes rust-lang#14798

Author: adamse

crates/rust-analyzer/src/config.rs

@@ -150,6 +150,10 @@ config_data! {
         ///
         /// Set to `"all"` to pass `--all-features` to Cargo.
         check_features | checkOnSave_features: Option<CargoFeaturesDef>  = "null",
+        /// List of `cargo check` (or other command specified in `check.command`) diagnostics to ignore.
+        ///
+        /// For example for `cargo check`: `dead_code`, `unused_imports`, `unused_variables`,...
+        check_ignore: FxHashSet<String> = "[]",
         /// Specifies the working directory for running checks.
         /// - "workspace": run checks for workspaces in the corresponding workspaces' root directories.
         // FIXME: Ideally we would support this in some way
@@ -1098,6 +1102,7 @@ impl Config {
             remap_prefix: self.data.diagnostics_remapPrefix.clone(),
             warnings_as_info: self.data.diagnostics_warningsAsInfo.clone(),
             warnings_as_hint: self.data.diagnostics_warningsAsHint.clone(),
+            check_ignore: self.data.check_ignore.clone(),
         }
     }
 

crates/rust-analyzer/src/diagnostics.rs

@@ -6,6 +6,7 @@ use std::mem;
 use ide::FileId;
 use ide_db::FxHashMap;
 use nohash_hasher::{IntMap, IntSet};
+use rustc_hash::FxHashSet;
 use triomphe::Arc;
 
 use crate::lsp_ext;
@@ -17,6 +18,7 @@ pub struct DiagnosticsMapConfig {
     pub remap_prefix: FxHashMap<String, String>,
     pub warnings_as_info: Vec<String>,
     pub warnings_as_hint: Vec<String>,
+    pub check_ignore: FxHashSet<String>,
 }
 
 #[derive(Debug, Default, Clone)]

crates/rust-analyzer/src/diagnostics/to_proto.rs

@@ -292,6 +292,13 @@ pub(crate) fn map_rust_diagnostic_to_lsp(
 
     let mut source = String::from("rustc");
     let mut code = rd.code.as_ref().map(|c| c.code.clone());
+
+    if let Some(code_val) = &code {
+        if config.check_ignore.contains(code_val) {
+            return Vec::new();
+        }
+    }
+
     if let Some(code_val) = &code {
         // See if this is an RFC #2103 scoped lint (e.g. from Clippy)
         let scoped_code: Vec<&str> = code_val.split("::").collect();

docs/user/generated_config.adoc

@@ -161,6 +161,13 @@ List of features to activate. Defaults to
 
 Set to `"all"` to pass `--all-features` to Cargo.
 --
+[[rust-analyzer.check.ignore]]rust-analyzer.check.ignore (default: `[]`)::
++
+--
+List of `cargo check` (or other command specified in `check.command`) diagnostics to ignore.
+
+For example for `cargo check`: `dead_code`, `unused_imports`, `unused_variables`,...
+--
 [[rust-analyzer.check.invocationLocation]]rust-analyzer.check.invocationLocation (default: `"workspace"`)::
 +
 --

editors/code/package.json

@@ -688,6 +688,15 @@
                         }
                     ]
                 },
+                "rust-analyzer.check.ignore": {
+                    "markdownDescription": "List of `cargo check` (or other command specified in `check.command`) diagnostics to ignore.\n\nFor example for `cargo check`: `dead_code`, `unused_imports`, `unused_variables`,...",
+                    "default": [],
+                    "type": "array",
+                    "items": {
+                        "type": "string"
+                    },
+                    "uniqueItems": true
+                },
                 "rust-analyzer.check.invocationLocation": {
                     "markdownDescription": "Specifies the working directory for running checks.\n- \"workspace\": run checks for workspaces in the corresponding workspaces' root directories.\n    This falls back to \"root\" if `#rust-analyzer.cargo.checkOnSave.invocationStrategy#` is set to `once`.\n- \"root\": run checks in the project's root directory.\nThis config only has an effect when `#rust-analyzer.cargo.buildScripts.overrideCommand#`\nis set.",
                     "default": "workspace",