SERVER-56932 failed optimizer error to have a specific code

jstests/core/const_folding_failure.js

@@ -0,0 +1,29 @@
+// Tests that checks if optimization errors raised with a specific code
+// @tags: [
+//    requires_fcv_51
+// ]
+
+(function() {
+"use strict";
+
+const coll = db.getCollection(jsTestName());
+
+coll.drop();
+
+// Forcing optimizer only failure (empty collection, $project will never execute)
+assert.throwsWithCode(() => db.nonexistent.aggregate([
+    {$project: 
+        {dt1: 
+            {$map:
+                {
+                    input: "$a",
+                    as: "b",
+                    in: {
+        $toDate: {
+            $dayOfYear: {
+                date: new Date("2019-04-08T11:48:29.394Z"),
+                timezone: "Australia/Melbourne"
+            }
+        }
+    }}}}}]), 5693200);
+})();

src/mongo/db/pipeline/document_source_internal_unpack_bucket.cpp

@@ -198,14 +198,6 @@ boost::intrusive_ptr<DocumentSourceSort> createMetadataSortForReorder(
                                       maxMemoryUsageBytes);
 }
 
-// Optimize the section of the pipeline before the $_internalUnpackBucket stage.
-void optimizePrefix(Pipeline::SourceContainer::iterator itr, Pipeline::SourceContainer* container) {
-    auto prefix = Pipeline::SourceContainer(container->begin(), itr);
-    Pipeline::optimizeContainer(&prefix);
-    container->erase(container->begin(), itr);
-    container->splice(itr, prefix);
-}
-
 // Returns whether 'field' depends on a pushed down $addFields or computed $project.
 bool fieldIsComputed(BucketSpec spec, std::string field) {
     return std::any_of(

src/mongo/db/pipeline/expression.cpp

@@ -6463,8 +6463,12 @@ boost::intrusive_ptr<Expression> ExpressionConvert::optimize() {
     // and _onNull values could still be legally folded if those values are not needed. Support for
     // that case would add more complexity than it's worth, though.
     if (ExpressionConstant::allNullOrConstant({_input, _to, _onError, _onNull})) {
-        return ExpressionConstant::create(
-            getExpressionContext(), evaluate(Document{}, &(getExpressionContext()->variables)));
+        try {
+            return ExpressionConstant::create(
+                getExpressionContext(), evaluate(Document{}, &(getExpressionContext()->variables)));
+        } catch (DBException& ex) {
+            uasserted(5693200, str::stream() << "Failed to optimize pipeline :: " + ex.reason());
+        }
     }
 
     return this;

src/mongo/db/pipeline/pipeline.cpp

@@ -26,20 +26,16 @@
  *    exception statement from all source files in the program, then also delete
  *    it in the license file.
  */
-
 #define MONGO_LOGV2_DEFAULT_COMPONENT ::mongo::logv2::LogComponent::kDefault
 
 #include "mongo/db/pipeline/pipeline.h"
 #include "mongo/logv2/log.h"
 
-#include <algorithm>
-
 #include "mongo/base/error_codes.h"
 #include "mongo/db/bson/dotted_path_support.h"
 #include "mongo/db/exec/document_value/document.h"
 #include "mongo/db/jsobj.h"
 #include "mongo/db/operation_context.h"
-#include "mongo/db/pipeline/accumulator.h"
 #include "mongo/db/pipeline/document_source.h"
 #include "mongo/db/pipeline/document_source_match.h"
 #include "mongo/db/pipeline/document_source_merge.h"
@@ -50,6 +46,8 @@
 #include "mongo/db/storage/storage_options.h"
 #include "mongo/util/fail_point.h"
 #include "mongo/util/str.h"
+#include <algorithm>
+
 
 namespace mongo {
 
@@ -669,6 +667,18 @@ std::unique_ptr<Pipeline, PipelineDeleter> Pipeline::makePipeline(
     return pipeline;
 }
 
+std::ostream& operator<<(std::ostream& os, const Pipeline& pipeline) {
+    vector<Value> serializedSources;
+    for (auto&& source : pipeline.getSources()) {
+        source->serializeToArray(serializedSources, explain::VerbosityEnum::kQueryPlanner);
+    }
+
+    for (auto stage : serializedSources) {
+        os << stage << " ";
+    }
+    return os;
+}
+
 Pipeline::SourceContainer::iterator Pipeline::optimizeEndOfPipeline(
     Pipeline::SourceContainer::iterator itr, Pipeline::SourceContainer* container) {
     // We must create a new SourceContainer representing the subsection of the pipeline we wish to

src/mongo/db/pipeline/pipeline.h

@@ -449,4 +449,9 @@ private:
     bool _dismissed = false;
 };
 
+/**
+ * Print operator useful for diagnostics
+ */
+std::ostream& operator<<(std::ostream& os, const Pipeline& pipeline);
+
 }  // namespace mongo