From 5bebaebcc06137755b0b78c0b51f65673033350d Mon Sep 17 00:00:00 2001
From: Sam Carlberg <sam@slfc.dev>
Date: Wed, 17 Dec 2025 01:23:30 -0500
Subject: [PATCH] [cmd3] Report incorrect coroutine usage on the variable use
 site (#8481)

This makes error messages point directly at the variable use, instead of
on the enclosing AST node:

```
error: `outerCoroutine` may not be in scope
    outerCoroutine.yield()
    ^

error: `outerCoroutine` may not be in scope
    consume(x, outerCoroutine);
               ^
```

instead of

```
error: `outerCoroutine` may not be in scope
    outerCoroutine.yield()
                        ^

error: `outerCoroutine` may not be in scope
    consume(x, outerCoroutine);
           ^
```
---
 .../wpilib/javacplugin/IncorrectCoroutineUseDetector.java  | 7 +++++--
 .../javacplugin/IncorrectCoroutineUseDetectorTest.java     | 7 +++++++
 2 files changed, 12 insertions(+), 2 deletions(-)

diff --git a/javacPlugin/src/main/java/org/wpilib/javacplugin/IncorrectCoroutineUseDetector.java b/javacPlugin/src/main/java/org/wpilib/javacplugin/IncorrectCoroutineUseDetector.java
index fb786ad456..7dcbd2fb4e 100644
--- a/javacPlugin/src/main/java/org/wpilib/javacplugin/IncorrectCoroutineUseDetector.java
+++ b/javacPlugin/src/main/java/org/wpilib/javacplugin/IncorrectCoroutineUseDetector.java
@@ -145,7 +145,7 @@ public class IncorrectCoroutineUseDetector extends CoroutineBasedDetector {
             && ve.asType().equals(m_coroutineType)
             && !state.isLocalCoroutine(ve)) {
           m_trees.printMessage(
-              Diagnostic.Kind.ERROR, nonlocalCoroutineUsageMessage(ve, state), node, m_root);
+              Diagnostic.Kind.ERROR, nonlocalCoroutineUsageMessage(ve, state), id, m_root);
         }
       }
 
@@ -157,7 +157,10 @@ public class IncorrectCoroutineUseDetector extends CoroutineBasedDetector {
             && ve.asType().equals(m_coroutineType)
             && !state.isLocalCoroutine(ve)) {
           m_trees.printMessage(
-              Diagnostic.Kind.ERROR, nonlocalCoroutineUsageMessage(ve, state), node, m_root);
+              Diagnostic.Kind.ERROR,
+              nonlocalCoroutineUsageMessage(ve, state),
+              argPath.getLeaf(),
+              m_root);
         }
       }
 
diff --git a/javacPlugin/src/test/java/org/wpilib/javacplugin/IncorrectCoroutineUseDetectorTest.java b/javacPlugin/src/test/java/org/wpilib/javacplugin/IncorrectCoroutineUseDetectorTest.java
index c719e7d1a3..652ae3838e 100644
--- a/javacPlugin/src/test/java/org/wpilib/javacplugin/IncorrectCoroutineUseDetectorTest.java
+++ b/javacPlugin/src/test/java/org/wpilib/javacplugin/IncorrectCoroutineUseDetectorTest.java
@@ -55,6 +55,7 @@ class IncorrectCoroutineUseDetectorTest {
     assertEquals(
         "Coroutine `outerCoroutine` may not be in scope. Consider using `innerCoroutine`",
         error.getMessage(null));
+    assertEquals(7, error.getColumnNumber()); // leading "o" in "outerCoroutine.yield()"
   }
 
   @Test
@@ -90,6 +91,8 @@ class IncorrectCoroutineUseDetectorTest {
     assertEquals(
         "Coroutine `outerCoroutine` may not be in scope. Consider using `innerCoroutine`",
         error.getMessage(null));
+    // leading "o" in "outerCoroutine" passed to `method(outerCoroutine)`
+    assertEquals(14, error.getColumnNumber());
   }
 
   @Test
@@ -126,6 +129,8 @@ class IncorrectCoroutineUseDetectorTest {
     assertEquals(
         "Coroutine `outerCoroutine` may not be in scope. Consider using `a` or `b`",
         error.getMessage(null));
+    // leading "o" in "outerCoroutine" passed to `method(outerCoroutine)`
+    assertEquals(14, error.getColumnNumber());
   }
 
   @Test
@@ -166,6 +171,8 @@ class IncorrectCoroutineUseDetectorTest {
     assertEquals(
         "Coroutine `outerCoroutine` may not be in scope. Consider using `a`, `b`, or `c`",
         error.getMessage(null));
+    // leading "o" in "outerCoroutine" passed to `method(outerCoroutine)`
+    assertEquals(14, error.getColumnNumber());
   }
 
   @Test