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[epilogue] Detailed trigger dependencies #8253

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[epilogue] Detailed trigger dependencies #8253

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7dfabed
Add @DependsOn annotation for dependency metadata
Raptorly1 Sep 24, 2025
f99b7d8
Update annotation processor to recognize @DependsOn
Raptorly1 Sep 24, 2025
d4f1099
Implement dependency logging in LoggerGenerator
Raptorly1 Sep 24, 2025
429eddf
Add test case for @DependsOn annotation processing
Raptorly1 Sep 24, 2025
2b13f61
Add LogMetadata class for dependency tracking
Raptorly1 Sep 25, 2025
e4ae20d
Extend EpilogueBackend with metadata-aware log methods
Raptorly1 Sep 25, 2025
815480f
Implement dependency metadata generation in LoggerGenerator
Raptorly1 Sep 25, 2025
98f0f6f
Update test expectations for dependency metadata feature
Raptorly1 Sep 25, 2025
eb28d17
Generate LogMetadata fields for elements with @DependsOn annotations …
Raptorly1 Sep 25, 2025
39e05ea
Refactor generateLogMetadata method to accept fields and methods list…
Raptorly1 Sep 25, 2025
37a2e52
Implement metadata-aware logging methods in EpilogueBackend and NTEpi…
Raptorly1 Sep 28, 2025
3ad142f
Add List import and update LogMetadata
Raptorly1 Sep 28, 2025
539a41d
Refactor LoggerGenerator to use static LogMetadata fields and update …
Raptorly1 Oct 2, 2025
79b132c
change FQN to import
Raptorly1 Oct 2, 2025
bcc1eeb
Update LoggerGenerator to validate @DependsOn dependencies and update…
Raptorly1 Oct 9, 2025
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89 changes: 72 additions & 17 deletions epilogue-processor/src/main/java/edu/wpi/first/epilogue/processor/LoggerGenerator.java
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Original file line number Diff line number Diff line change
Expand Up @@ -250,13 +250,32 @@ private void writeLoggerFile(
out.println();
}

// Static initializer block to load VarHandles and reflection fields
if (requiresVarHandles) {
out.println(" static {");
// Generate static final LogMetadata fields for elements with @DependsOn annotations
List<Element> logMetadataElements = Stream.concat(loggableFields.stream(), loggableMethods.stream())
.filter(element -> element.getAnnotation(DependsOn.class) != null ||
element.getAnnotation(DependsOn.Container.class) != null)
.sorted(Comparator.comparing(e -> e.getSimpleName().toString()))
.collect(Collectors.toList());

if (!logMetadataElements.isEmpty()) {
for (var element : logMetadataElements) {
// Generate static final LogMetadata field for caching
out.printf(
" // Cached LogMetadata for element %s with @DependsOn annotations%n",
element.getSimpleName());
out.printf(" private static final LogMetadata %s;%n", logMetadataFieldName(element));
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Why can't we initialize the LogMetadata caches inline with the field declarations? (e.g., private static final LogMetadata $metadata_edu_wpi_first_epilogue_Example_isAtTarget = new LogMetadata(List.of("position", "target", "tolerance"));)
This would mean that we can remove the code in the static {} initializer block, which would greater simplify the logic.

}
out.println();
}

out.println(" try {");
// Static initializer block to load VarHandles and initialize LogMetadata fields
if (requiresVarHandles || !logMetadataElements.isEmpty()) {
out.println(" static {");

out.println(" var rootLookup = MethodHandles.lookup();");
if (requiresVarHandles) {
out.println(" try {");
out.println(" var rootLookup = MethodHandles.lookup();");
}

// Group private fields by class, then generate a private lookup for each class
// and a VarHandle for each field using that lookup. Sorting and then collecting into a
Expand Down Expand Up @@ -294,11 +313,19 @@ private void writeLoggerFile(
}
});

out.println(" } catch (ReflectiveOperationException e) {");
out.println(
" throw new RuntimeException("
+ "\"[EPILOGUE] Could not load private fields for logging!\", e);");
out.println(" }");
if (requiresVarHandles) {
out.println(" } catch (ReflectiveOperationException e) {");
out.println(
" throw new RuntimeException("
+ "\"[EPILOGUE] Could not load private fields for logging!\", e);");
out.println(" }");
}

// Initialize static final LogMetadata fields
for (var element : logMetadataElements) {
String metadataInitialization = generateLogMetadata(element, clazz, false); // Use inline construction for static field initialization
out.printf(" %s = %s;%n", logMetadataFieldName(element), metadataInitialization);
}

out.println(" }");
out.println();
Expand Down Expand Up @@ -356,7 +383,7 @@ private void writeLoggerFile(
// Generate log invocation for the main element
var metadata = generateLogMetadata(loggableElement, clazz);
if (metadata != null) {
var modifiedInvocation = logInvocation.replaceFirst("\\)$", ", " + metadata + ")");
var modifiedInvocation = logInvocation.replaceFirst("\\)$", java.util.regex.Matcher.quoteReplacement(", " + metadata + ")"));
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Can we import Matcher here?

out.println(modifiedInvocation.indent(6).stripTrailing() + ";");
} else {
out.println(logInvocation.indent(6).stripTrailing() + ";");
Expand Down Expand Up @@ -385,6 +412,18 @@ public static String varHandleName(VariableElement field) {
.formatted(field.getEnclosingElement().toString().replace(".", "_"), field.getSimpleName());
}

/**
* Generates the name of a static final LogMetadata field for the given element. The field name
* is guaranteed to be unique.
*
* @param element The element to generate a LogMetadata field for
* @return The name of the generated LogMetadata field
*/
public static String logMetadataFieldName(Element element) {
return "$metadata_%s_%s"
.formatted(element.getEnclosingElement().toString().replace(".", "_"), element.getSimpleName());
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How will this behave if a logged field and a logged method have the same simple name?

@Logged
class Example {
  @Logged
  int foo = 0;
  
  @Logged
  public int foo() { return 42; }
}

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It compiles right now, but that's a good question. Should I try making it disambiguous? Maybe we could append suffixes?

}

private void collectLoggables(
TypeElement clazz, List<VariableElement> fields, List<ExecutableElement> methods) {
var config = clazz.getAnnotation(Logged.class);
Expand Down Expand Up @@ -499,6 +538,18 @@ public Boolean visitIdentifier(IdentifierTree identifier, Void unused) {
* @return LogMetadata containing dependency names, or null if no valid dependencies
*/
private String generateLogMetadata(Element element, TypeElement clazz) {
return generateLogMetadata(element, clazz, true);
}

/**
* Creates LogMetadata for dependencies of an element marked with @DependsOn annotations.
*
* @param element the element that has @DependsOn annotations
* @param clazz the class containing the element
* @param useStaticField if true, return static field reference; if false, return inline construction
* @return LogMetadata construction code or field reference, or null if no valid dependencies
*/
private String generateLogMetadata(Element element, TypeElement clazz, boolean useStaticField) {
// Check for @DependsOn annotations (both single and multiple via @DependsOn.Container)
List<DependsOn> dependencies = new ArrayList<>();

Expand Down Expand Up @@ -533,12 +584,16 @@ private String generateLogMetadata(Element element, TypeElement clazz) {
return null;
}

// Create LogMetadata construction code
String dependencyList = validDependencyNames.stream()
.map(name -> "\"" + name + "\"")
.collect(java.util.stream.Collectors.joining(", "));

return "new edu.wpi.first.epilogue.logging.LogMetadata(java.util.List.of(" + dependencyList + "))";
if (useStaticField) {
// Return reference to static final field
return logMetadataFieldName(element);
} else {
// Create LogMetadata construction code for static field initialization
String dependencyList = validDependencyNames.stream()
.map(name -> "\"" + name + "\"")
.collect(java.util.stream.Collectors.joining(", "));
return "new edu.wpi.first.epilogue.logging.LogMetadata(java.util.List.of(" + dependencyList + "))";
}
}

/**
Expand Down
9 changes: 8 additions & 1 deletion ...gue-processor/src/test/java/edu/wpi/first/epilogue/processor/AnnotationProcessorTest.java
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Original file line number Diff line number Diff line change
Expand Up @@ -2348,6 +2348,13 @@ public boolean isAtTarget() {
import edu.wpi.first.epilogue.logging.LogMetadata;

public class ExampleLogger extends ClassSpecificLogger<Example> {
// Cached LogMetadata for element isAtTarget with @DependsOn annotations
private static final LogMetadata $metadata_edu_wpi_first_epilogue_Example_isAtTarget;

static {
$metadata_edu_wpi_first_epilogue_Example_isAtTarget = new edu.wpi.first.epilogue.logging.LogMetadata(java.util.List.of("position", "target", "tolerance"));
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@SamCarlberg SamCarlberg Sep 26, 2025 •
edited
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Let's have imports for these types. Even though the file is generated, it'd be nice to be more human-friendly

}

public ExampleLogger() {
super(Example.class);
}
Expand All @@ -2358,7 +2365,7 @@ public void update(EpilogueBackend backend, Example object) {
backend.log("position", object.position);
backend.log("target", object.target);
backend.log("tolerance", object.tolerance);
backend.log("isAtTarget", object.isAtTarget(), new edu.wpi.first.epilogue.logging.LogMetadata(java.util.List.of("position", "target", "tolerance")));
backend.log("isAtTarget", object.isAtTarget(), $metadata_edu_wpi_first_epilogue_Example_isAtTarget);
}
}
}
Expand Down