From c6bafa7322943643f37f8818bcb16dad28f53d26 Mon Sep 17 00:00:00 2001
From: Jeremy Fitzhardinge <jeremy@goop.org>
Date: Sat, 16 Apr 2022 17:11:33 -0700
Subject: Add --json unused-externs-silent with original behaviour

Since Cargo wants to do its own fatal error handling for unused
dependencies, add the option `--json unused-externs-silent` which
has the original behaviour of not indicating non-zero exit status for
`deny`/`forbid`-level unused dependencies.
---
 compiler/rustc_session/src/config.rs  | 38 ++++++++++++++++++++++++++++++-----
 compiler/rustc_session/src/options.rs |  2 +-
 2 files changed, 34 insertions(+), 6 deletions(-)

(limited to 'compiler/rustc_session/src')

diff --git a/compiler/rustc_session/src/config.rs b/compiler/rustc_session/src/config.rs
index 925f6bfd93d..5851ed43a0e 100644
--- a/compiler/rustc_session/src/config.rs
+++ b/compiler/rustc_session/src/config.rs
@@ -757,7 +757,7 @@ impl Default for Options {
             real_rust_source_base_dir: None,
             edition: DEFAULT_EDITION,
             json_artifact_notifications: false,
-            json_unused_externs: false,
+            json_unused_externs: JsonUnusedExterns::No,
             json_future_incompat: false,
             pretty: None,
             working_dir: RealFileName::LocalPath(std::env::current_dir().unwrap()),
@@ -1493,10 +1493,37 @@ pub fn parse_color(matches: &getopts::Matches) -> ColorConfig {
 pub struct JsonConfig {
     pub json_rendered: HumanReadableErrorType,
     pub json_artifact_notifications: bool,
-    pub json_unused_externs: bool,
+    pub json_unused_externs: JsonUnusedExterns,
     pub json_future_incompat: bool,
 }
 
+/// Report unused externs in event stream
+#[derive(Copy, Clone)]
+pub enum JsonUnusedExterns {
+    /// Do not
+    No,
+    /// Report, but do not exit with failure status for deny/forbid
+    Silent,
+    /// Report, and also exit with failure status for deny/forbid
+    Loud,
+}
+
+impl JsonUnusedExterns {
+    pub fn is_enabled(&self) -> bool {
+        match self {
+            JsonUnusedExterns::No => false,
+            JsonUnusedExterns::Loud | JsonUnusedExterns::Silent => true,
+        }
+    }
+
+    pub fn is_loud(&self) -> bool {
+        match self {
+            JsonUnusedExterns::No | JsonUnusedExterns::Silent => false,
+            JsonUnusedExterns::Loud => true,
+        }
+    }
+}
+
 /// Parse the `--json` flag.
 ///
 /// The first value returned is how to render JSON diagnostics, and the second
@@ -1506,7 +1533,7 @@ pub fn parse_json(matches: &getopts::Matches) -> JsonConfig {
         HumanReadableErrorType::Default;
     let mut json_color = ColorConfig::Never;
     let mut json_artifact_notifications = false;
-    let mut json_unused_externs = false;
+    let mut json_unused_externs = JsonUnusedExterns::No;
     let mut json_future_incompat = false;
     for option in matches.opt_strs("json") {
         // For now conservatively forbid `--color` with `--json` since `--json`
@@ -1524,7 +1551,8 @@ pub fn parse_json(matches: &getopts::Matches) -> JsonConfig {
                 "diagnostic-short" => json_rendered = HumanReadableErrorType::Short,
                 "diagnostic-rendered-ansi" => json_color = ColorConfig::Always,
                 "artifacts" => json_artifact_notifications = true,
-                "unused-externs" => json_unused_externs = true,
+                "unused-externs" => json_unused_externs = JsonUnusedExterns::Loud,
+                "unused-externs-silent" => json_unused_externs = JsonUnusedExterns::Silent,
                 "future-incompat" => json_future_incompat = true,
                 s => early_error(
                     ErrorOutputType::default(),
@@ -2224,7 +2252,7 @@ pub fn build_session_options(matches: &getopts::Matches) -> Options {
 
     check_debug_option_stability(&debugging_opts, error_format, json_rendered);
 
-    if !debugging_opts.unstable_options && json_unused_externs {
+    if !debugging_opts.unstable_options && json_unused_externs.is_enabled() {
         early_error(
             error_format,
             "the `-Z unstable-options` flag must also be passed to enable \
diff --git a/compiler/rustc_session/src/options.rs b/compiler/rustc_session/src/options.rs
index 96f50e57ac4..14e918660dd 100644
--- a/compiler/rustc_session/src/options.rs
+++ b/compiler/rustc_session/src/options.rs
@@ -221,7 +221,7 @@ top_level_options!(
         json_artifact_notifications: bool [TRACKED],
 
         /// `true` if we're emitting a JSON blob containing the unused externs
-        json_unused_externs: bool [UNTRACKED],
+        json_unused_externs: JsonUnusedExterns [UNTRACKED],
 
         /// `true` if we're emitting a JSON job containing a future-incompat report for lints
         json_future_incompat: bool [TRACKED],
-- 
cgit 1.4.1-3-g733a5