improve error messages when verifying rank setup

4 files changed, 37 insertions, 5 deletions

diff --git a/searchlib/src/tests/fef/resolver/resolver_test.cpp b/searchlib/src/tests/fef/resolver/resolver_test.cpp
index 77aba1664ad..536507f3776 100644
--- a/searchlib/src/tests/fef/resolver/resolver_test.cpp
+++ b/searchlib/src/tests/fef/resolver/resolver_test.cpp
@@ -86,4 +86,10 @@ TEST_F("require_that_bad_input_is_handled", Fixture) {
     EXPECT_TRUE(dynamic_cast<RankingExpressionBlueprint *>(spec[1].blueprint.get()) != nullptr);
 }
 
+TEST("require that features can be described") {
+    EXPECT_EQUAL(BlueprintResolver::describe_feature("featureName"), vespalib::string("rank feature 'featureName'"));
+    EXPECT_EQUAL(BlueprintResolver::describe_feature("rankingExpression(foo)"), vespalib::string("function 'foo'"));
+    EXPECT_EQUAL(BlueprintResolver::describe_feature("rankingExpression(foo@1234.5678)"), vespalib::string("function 'foo'"));
+}
+
 TEST_MAIN() { TEST_RUN_ALL(); }
diff --git a/searchlib/src/vespa/searchlib/fef/blueprintresolver.cpp b/searchlib/src/vespa/searchlib/fef/blueprintresolver.cpp
index 2a12867dd33..731306d1bea 100644
--- a/searchlib/src/vespa/searchlib/fef/blueprintresolver.cpp
+++ b/searchlib/src/vespa/searchlib/fef/blueprintresolver.cpp
@@ -28,6 +28,10 @@ constexpr int TRACE_SKIP_POS = 10;
 
 using Accept = Blueprint::AcceptInput;
 
+vespalib::string describe(const vespalib::string &feature_name) {
+    return BlueprintResolver::describe_feature(feature_name);
+}
+
 bool is_compatible(bool is_object, Accept accept_type) {
     return ((accept_type == Accept::ANY) ||
             ((accept_type == Accept::OBJECT) == (is_object)));
@@ -122,7 +126,7 @@ struct Compiler : public Blueprint::DependencyHandler {
             should_trace |= (i < TRACE_SKIP_POS);
             should_trace |= ((end - pos) < (MAX_TRACE_SIZE - TRACE_SKIP_POS));
             if (should_trace) {
-                trace += fmt("  ... needed by rank feature '%s'\n", pos->parser.featureName().c_str());
+                trace += fmt("  ... needed by %s\n", describe(pos->parser.featureName()).c_str());
             } else if (i == TRACE_SKIP_POS) {
                 trace += fmt("  (skipped %zu entries)\n", (n - MAX_TRACE_SIZE) + 1);
             }
@@ -135,9 +139,9 @@ struct Compiler : public Blueprint::DependencyHandler {
             failed_set.insert(feature_name);
             auto trace = make_trace(skip_self);
             if (trace.empty()) {
-                LOG(warning, "invalid rank feature '%s': %s", feature_name.c_str(), reason.c_str());
+                LOG(warning, "invalid %s: %s", describe(feature_name).c_str(), reason.c_str());
             } else {
-                LOG(warning, "invalid rank feature '%s': %s\n%s", feature_name.c_str(), reason.c_str(), trace.c_str());
+                LOG(warning, "invalid %s: %s\n%s", describe(feature_name).c_str(), reason.c_str(), trace.c_str());
             }
         }
         probe_stack();
@@ -264,6 +268,22 @@ BlueprintResolver::BlueprintResolver(const BlueprintFactory &factory,
 {
 }
 
+vespalib::string
+BlueprintResolver::describe_feature(const vespalib::string &name)
+{
+    auto parser = std::make_unique<FeatureNameParser>(name);
+    if (parser->valid() &&
+        (parser->baseName() == "rankingExpression") &&
+        (parser->parameters().size() == 1) &&
+        parser->output().empty())
+    {
+        auto param = parser->parameters()[0];
+        param = param.substr(0, param.find("@"));
+        return fmt("function '%s'", param.c_str());
+    }
+    return fmt("rank feature '%s'", name.c_str());
+}
+
 void
 BlueprintResolver::addSeed(vespalib::stringref feature)
 {
diff --git a/searchlib/src/vespa/searchlib/fef/blueprintresolver.h b/searchlib/src/vespa/searchlib/fef/blueprintresolver.h
index 80320ae780a..3e3b5879518 100644
--- a/searchlib/src/vespa/searchlib/fef/blueprintresolver.h
+++ b/searchlib/src/vespa/searchlib/fef/blueprintresolver.h
@@ -100,6 +100,12 @@ public:
     BlueprintResolver(const BlueprintFactory &factory,
                       const IIndexEnvironment &indexEnv);
 
+    // Describe a feature based on its name (intended for log messages)
+    //
+    // rankingExpression(foo@hash) -> function 'foo'
+    // feature -> rank feature 'feature'
+    static vespalib::string describe_feature(const vespalib::string &name);
+
     /**
      * Add a feature name to the list of seeds. During compilation,
      * blueprints for all seeds and dependencies will be instantiated
diff --git a/searchlib/src/vespa/searchlib/fef/verify_feature.cpp b/searchlib/src/vespa/searchlib/fef/verify_feature.cpp
index d61d7faef0f..85d1daffd01 100644
--- a/searchlib/src/vespa/searchlib/fef/verify_feature.cpp
+++ b/searchlib/src/vespa/searchlib/fef/verify_feature.cpp
@@ -19,8 +19,8 @@ bool verifyFeature(const BlueprintFactory &factory,
     resolver.addSeed(featureName);
     bool result = resolver.compile();
     if (!result) {
-        LOG(error, "rank feature verification failed: %s (%s)",
-            featureName.c_str(), desc.c_str());
+        LOG(error, "verification failed: %s (%s)",
+            BlueprintResolver::describe_feature(featureName).c_str(), desc.c_str());
     }
     return result;
 }