On demand SourceMap JSON serialization (#2811)

* #include an absolute path didn't work - because paths were taken to always be relative.

* Moved JSON source map writing logic to JSONSourceMapUtil.

* Use ArtifactHandler to read/write SourceMaps.
Use ObjectCastableAdapter to hold SourceMap
Only serialize SourceMap <-> JSON on demand.

4 files changed, 98 insertions, 2 deletions

diff --git a/source/compiler-core/slang-artifact-handler-impl.cpp b/source/compiler-core/slang-artifact-handler-impl.cpp
index 985aa2337..1a8e8374d 100644
--- a/source/compiler-core/slang-artifact-handler-impl.cpp
+++ b/source/compiler-core/slang-artifact-handler-impl.cpp
@@ -17,6 +17,10 @@
 #include "../core/slang-io.h"
 #include "../core/slang-shared-library.h"
 
+#include "slang-source-map.h"
+
+#include "slang-json-source-map-util.h"
+
 namespace Slang {
 
 /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!! DefaultArtifactHandler !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! */
@@ -126,6 +130,25 @@ SlangResult DefaultArtifactHandler::expandChildren(IArtifact* container)
 	return SLANG_OK;
 }
 
+static SlangResult _loadSourceMap(IArtifact* artifact, ArtifactKeep intermediateKeep, RefPtr<SourceMap>& outSourceMap)
+{
+	const auto desc = artifact->getDesc();
+	if (isDerivedFrom(desc.kind, ArtifactKind::Json) &&
+		isDerivedFrom(desc.payload, ArtifactPayload::SourceMap))
+	{
+		ComPtr<ISlangBlob> blob;
+		SLANG_RETURN_ON_FAIL(artifact->loadBlob(intermediateKeep, blob.writeRef()));
+
+		RefPtr<SourceMap> sourceMap;
+		SLANG_RETURN_ON_FAIL(JSONSourceMapUtil::read(blob, sourceMap));
+
+		outSourceMap = sourceMap;
+		return SLANG_OK;
+	}
+
+	return SLANG_FAIL;
+}
+
 SlangResult DefaultArtifactHandler::getOrCreateRepresentation(IArtifact* artifact, const Guid& guid, ArtifactKeep keep, ICastable** outCastable)
 {
 	const auto reps = artifact->getRepresentations();
@@ -156,8 +179,16 @@ SlangResult DefaultArtifactHandler::getOrCreateRepresentation(IArtifact* artifac
 		}
 	}
 
-	// Special case shared library
-	if (guid == ISlangSharedLibrary::getTypeGuid())
+	// Special cases
+	if (guid == SourceMap::getTypeGuid())
+	{
+		// Blob -> SourceMap
+		RefPtr<SourceMap> sourceMap;
+		SLANG_RETURN_ON_FAIL(_loadSourceMap(artifact, getIntermediateKeep(keep), sourceMap));
+		ComPtr<IObjectCastableAdapter> castable(new ObjectCastableAdapter(sourceMap));
+		return _addRepresentation(artifact, keep, castable, outCastable);
+	}
+	else if (guid == ISlangSharedLibrary::getTypeGuid())
 	{
 		ComPtr<ISlangSharedLibrary> sharedLib;
 		SLANG_RETURN_ON_FAIL(_loadSharedLibrary(artifact, sharedLib.writeRef()));
@@ -169,6 +200,20 @@ SlangResult DefaultArtifactHandler::getOrCreateRepresentation(IArtifact* artifac
 		SLANG_RETURN_ON_FAIL(_createOSFile(artifact, getIntermediateKeep(keep), fileRep.writeRef()));
 		return _addRepresentation(artifact, keep, fileRep, outCastable);
 	}
+	else if (guid == ISlangBlob::getTypeGuid())
+	{
+		for (ICastable* rep : reps)
+		{
+			if (SourceMap* sourceMap = as<SourceMap>(rep))
+			{
+				// SourceMap -> Blob
+				ComPtr<ISlangBlob> blob;
+				SLANG_RETURN_ON_FAIL(JSONSourceMapUtil::write(sourceMap, blob));
+				// Add the rep
+				return _addRepresentation(artifact, keep, blob, outCastable);
+			}
+		}
+	}
 
 	return SLANG_E_NOT_AVAILABLE;
 }
diff --git a/source/compiler-core/slang-json-source-map-util.cpp b/source/compiler-core/slang-json-source-map-util.cpp
index 3929a3387..4ef6ee3d6 100644
--- a/source/compiler-core/slang-json-source-map-util.cpp
+++ b/source/compiler-core/slang-json-source-map-util.cpp
@@ -3,6 +3,7 @@
 #include "../../slang-com-helper.h"
 
 #include "../core/slang-string-util.h"
+#include "../core/slang-blob.h"
 
 #include "slang-json-native.h"
 
@@ -454,6 +455,11 @@ SlangResult JSONSourceMapUtil::encode(SourceMap* sourceMap, JSONContainer* conta
     return SLANG_OK;
 }
 
+/* static */SlangResult JSONSourceMapUtil::read(ISlangBlob* blob, RefPtr<SourceMap>& outSourceMap)
+{
+    return read(blob, nullptr, outSourceMap);
+}
+
 SlangResult JSONSourceMapUtil::read(ISlangBlob* blob, DiagnosticSink* parentSink, RefPtr<SourceMap>& outSourceMap)
 {
     SourceManager sourceManager;
@@ -489,4 +495,41 @@ SlangResult JSONSourceMapUtil::read(ISlangBlob* blob, DiagnosticSink* parentSink
     return SLANG_OK;
 }
 
+
+/* static */SlangResult JSONSourceMapUtil::write(SourceMap* sourceMap, ComPtr<ISlangBlob>& outBlob)
+{
+    SourceManager sourceMapSourceManager;
+    sourceMapSourceManager.initialize(nullptr, nullptr);
+
+    // Create a sink
+    DiagnosticSink sourceMapSink(&sourceMapSourceManager, nullptr);
+
+    SLANG_RETURN_ON_FAIL(write(sourceMap, &sourceMapSink, outBlob));
+    return SLANG_OK;
+}
+
+/* static */ SlangResult JSONSourceMapUtil::write(SourceMap* sourceMap, DiagnosticSink* sink, ComPtr<ISlangBlob>& outBlob)
+{
+    auto sourceManager = sink->getSourceManager();
+
+    // Write it out
+    String json;
+    {
+        RefPtr<JSONContainer> jsonContainer(new JSONContainer(sourceManager));
+
+        JSONValue jsonValue;
+
+        SLANG_RETURN_ON_FAIL(JSONSourceMapUtil::encode(sourceMap, jsonContainer, sink, jsonValue));
+
+        // Convert into a string
+        JSONWriter writer(JSONWriter::IndentationStyle::Allman);
+        jsonContainer->traverseRecursively(jsonValue, &writer);
+
+        json = writer.getBuilder();
+    }
+
+    outBlob = StringBlob::moveCreate(json);
+    return SLANG_OK;
+}
+
 } // namespace Slang
diff --git a/source/compiler-core/slang-json-source-map-util.h b/source/compiler-core/slang-json-source-map-util.h
index ba417dd7c..8d5071d4e 100644
--- a/source/compiler-core/slang-json-source-map-util.h
+++ b/source/compiler-core/slang-json-source-map-util.h
@@ -18,6 +18,12 @@ struct  JSONSourceMapUtil
         /// Read the blob (encoded as JSON) as a source map. 
         /// Sink is optional, and can be passed as nullptr
     static SlangResult read(ISlangBlob* blob, DiagnosticSink* sink, RefPtr<SourceMap>& outSourceMap);
+    static SlangResult read(ISlangBlob* blob, RefPtr<SourceMap>& outSourceMap);
+
+        /// Write source map to outBlob JSON
+    static SlangResult write(SourceMap* sourceMap, ComPtr<ISlangBlob>& outBlob);
+        /// Write out the source map into a blob
+    static SlangResult write(SourceMap* sourceMap, DiagnosticSink* sink, ComPtr<ISlangBlob>& outBlob);
 };
 
 } // namespace Slang
diff --git a/source/compiler-core/slang-source-map.h b/source/compiler-core/slang-source-map.h
index 1ccc87e90..f1338508f 100644
--- a/source/compiler-core/slang-source-map.h
+++ b/source/compiler-core/slang-source-map.h
@@ -13,6 +13,8 @@ namespace Slang {
 class SourceMap : public RefObject
 {
 public:
+    SLANG_CLASS_GUID(0x731383ea, 0xe516, 0x4cc3, { 0xa6, 0xcf, 0x37, 0xd2, 0x8c, 0x24, 0x5c, 0x5e });
+
     struct Entry
     {
         void init()