fix(log): log target name and kind

Instead of all unnecesary field,
just track kind and in log.

Detailed info can be retrieved from `cargo metadata` or other tools

Author: weihanglo

src/cargo/core/compiler/fingerprint/mod.rs

@@ -454,7 +454,7 @@ pub fn prepare_target(
         if !dirty_reason.is_fresh_build() {
             logger.log(LogMessage::Rebuild {
                 package_id: unit.pkg.package_id().to_spec(),
-                target: unit.target.clone(),
+                target: (&unit.target).into(),
                 mode: unit.mode,
                 cause: dirty_reason.clone(),
             });

src/cargo/core/compiler/timings/mod.rs

@@ -277,7 +277,7 @@ impl<'gctx> Timings<'gctx> {
         if let Some(logger) = build_runner.bcx.logger {
             logger.log(LogMessage::UnitFinished {
                 package_id: unit_time.unit.pkg.package_id().to_spec(),
-                target: unit_time.unit.target.clone(),
+                target: (&unit_time.unit.target).into(),
                 mode: unit_time.unit.mode,
                 duration: unit_time.duration,
                 rmeta_time: unit_time.rmeta_time,

src/cargo/util/log_message.rs

@@ -7,7 +7,6 @@ use cargo_util_schemas::core::PackageIdSpec;
 use jiff::Timestamp;
 use serde::Serialize;
 
-use crate::core::Target;
 use crate::core::compiler::CompilationSection;
 use crate::core::compiler::CompileMode;
 use crate::core::compiler::fingerprint::DirtyReason;
@@ -49,6 +48,29 @@ pub enum LogMessage {
     },
 }
 
+#[derive(Serialize)]
+pub struct Target {
+    name: String,
+    kind: &'static str,
+}
+
+impl From<&crate::core::Target> for Target {
+    fn from(target: &crate::core::Target) -> Self {
+        use crate::core::TargetKind;
+        Self {
+            name: target.name().to_string(),
+            kind: match target.kind() {
+                TargetKind::Lib(..) => "lib",
+                TargetKind::Bin => "bin",
+                TargetKind::Test => "test",
+                TargetKind::Bench => "bench",
+                TargetKind::ExampleLib(..) | TargetKind::ExampleBin => "example",
+                TargetKind::CustomBuild => "build-script",
+            },
+        }
+    }
+}
+
 impl LogMessage {
     /// Serializes this message as a JSON log line directly to the writer.
     pub fn write_json_log<W: Write>(&self, writer: &mut W, run_id: &str) -> std::io::Result<()> {

tests/testsuite/build_analysis.rs

@@ -127,8 +127,8 @@ fn log_msg_timing_info() {
         str![[r#"
 [
   {
-    "reason": "build-started",
-    "...": "{...}"
+    "...": "{...}",
+    "reason": "build-started"
   },
   {
     "duration": "{...}",
@@ -137,7 +137,10 @@ fn log_msg_timing_info() {
     "reason": "unit-finished",
     "rmeta_time": "{...}",
     "run_id": "[..]T[..]Z-[..]",
-    "target": "{...}",
+    "target": {
+      "kind": "lib",
+      "name": "bar"
+    },
     "timestamp": "[..]T[..]Z"
   },
   {
@@ -147,7 +150,10 @@ fn log_msg_timing_info() {
     "reason": "unit-finished",
     "rmeta_time": "{...}",
     "run_id": "[..]T[..]Z-[..]",
-    "target": "{...}",
+    "target": {
+      "kind": "lib",
+      "name": "foo"
+    },
     "timestamp": "[..]T[..]Z"
   }
 ]
@@ -241,7 +247,10 @@ fn log_rebuild_reason_file_changed() {
     "package_id": "path+[ROOTURL]/foo#0.0.0",
     "reason": "rebuild",
     "run_id": "[..]T[..]Z-[..]",
-    "target": "{...}",
+    "target": {
+      "kind": "lib",
+      "name": "foo"
+    },
     "timestamp": "[..]T[..]Z"
   },
   {