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.

9 files changed, 194 insertions, 55 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()
diff --git a/source/core/slang-castable.cpp b/source/core/slang-castable.cpp
index f3c6541dd..6b7644bf2 100644
--- a/source/core/slang-castable.cpp
+++ b/source/core/slang-castable.cpp
@@ -20,6 +20,37 @@ namespace Slang {
     return castable;
 }
 
+/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! ObjectCastableAdapter !!!!!!!!!!!!!!!!!!!!!!!!!!! */
+
+void* ObjectCastableAdapter::castAs(const Guid& guid)
+{
+    if (auto intf = getInterface(guid))
+    {
+        return intf;
+    }
+    return getObject(guid);
+}
+
+void* ObjectCastableAdapter::getInterface(const Guid& guid)
+{
+    if (guid == ISlangUnknown::getTypeGuid() ||
+        guid == ICastable::getTypeGuid() ||
+        guid == IObjectCastableAdapter::getTypeGuid())
+    {
+        return static_cast<IObjectCastableAdapter*>(this);
+    }
+    return nullptr;
+}
+
+void* ObjectCastableAdapter::getObject(const Guid& guid)
+{
+    if (guid == m_containedGuid)
+    {
+        return m_contained;
+    }
+    return nullptr;
+}
+
 /* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! UnknownCastableAdapter !!!!!!!!!!!!!!!!!!!!!!!!!!! */
 
 void* UnknownCastableAdapter::castAs(const Guid& guid)
diff --git a/source/core/slang-castable.h b/source/core/slang-castable.h
index a72822f05..4f4fdc940 100644
--- a/source/core/slang-castable.h
+++ b/source/core/slang-castable.h
@@ -35,6 +35,58 @@ SLANG_FORCE_INLINE T* as(ICastable* castable)
     return nullptr;
 }
 
+/* Adapter interface to make non castable ref counted object usable as ICastable */
+class IObjectCastableAdapter : public ICastable
+{
+    SLANG_COM_INTERFACE(0x8b4aad81, 0x4934, 0x4a67, { 0xb2, 0xe2, 0xe9, 0x17, 0xfc, 0x29, 0x12, 0x54 });
+
+        /// Get the contained object
+    virtual SLANG_NO_THROW RefObject* SLANG_MCALL getContained() = 0;
+        /// Get the guid that represents the contained ref object
+    virtual SLANG_NO_THROW SlangUUID getContainedGuid() = 0;
+};
+
+class ObjectCastableAdapter : public ComBaseObject, public IObjectCastableAdapter
+{
+public:
+    SLANG_COM_BASE_IUNKNOWN_ALL
+
+    // ICastable
+    SLANG_NO_THROW void* SLANG_MCALL castAs(const Guid& guid) SLANG_OVERRIDE;
+
+    // IObjectCastableAdapter
+    virtual SLANG_NO_THROW RefObject* SLANG_MCALL getContained() SLANG_OVERRIDE { return m_contained; }
+    virtual SlangUUID getContainedGuid() SLANG_OVERRIDE { return m_containedGuid; }
+
+    template <typename T>
+    explicit ObjectCastableAdapter(T* ptr)
+    {
+        m_containedGuid = T::getTypeGuid();
+        m_contained = ptr;
+    }
+    template <typename T>
+    explicit ObjectCastableAdapter(const RefPtr<T>& ptr)
+    {
+        m_containedGuid = T::getTypeGuid();
+        m_contained = ptr;
+    }
+
+    ObjectCastableAdapter(RefObject* obj, const Guid& containedGuid) :
+        m_contained(obj),
+        m_containedGuid(containedGuid)
+    {
+        SLANG_ASSERT(obj);
+    }
+
+protected:
+    void* getInterface(const Guid& guid);
+    void* getObject(const Guid& guid);
+
+    RefPtr<RefObject> m_contained;
+    SlangUUID m_containedGuid;
+};
+
+
 /* Adapter interface to make a non castable types work as ICastable */
 class IUnknownCastableAdapter : public ICastable
 {
@@ -44,6 +96,7 @@ class IUnknownCastableAdapter : public ICastable
     virtual SLANG_NO_THROW ISlangUnknown* SLANG_MCALL getContained() = 0;
 };
 
+
 /* An adapter such that types which aren't derived from ICastable, can be used as such. 
 
 With the following caveats.
diff --git a/source/slang/slang-compiler.cpp b/source/slang/slang-compiler.cpp
index becd65596..907f39f48 100644
--- a/source/slang/slang-compiler.cpp
+++ b/source/slang/slang-compiler.cpp
@@ -15,8 +15,6 @@
 
 #include "../compiler-core/slang-lexer.h"
 
-#include "../compiler-core/slang-json-source-map-util.h"
-
 // Artifact
 #include "../compiler-core/slang-artifact-desc-util.h"
 #include "../compiler-core/slang-artifact-representation-impl.h"
@@ -1902,9 +1900,6 @@ namespace Slang
 
         auto frontEndReq = getFrontEndReq();
 
-        auto sourceManager = frontEndReq->getSourceManager();
-        auto sink = getSink();
-
         for (auto translationUnit : frontEndReq->translationUnits)
         {
             // Hmmm do I have to therefore add a map for all translation units(!)
@@ -1915,29 +1910,14 @@ namespace Slang
             // If we have a source map *and* we want to generate them for output add to the container
             if (sourceMap && getLinkage()->m_generateSourceMap)
             {
-                // 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();
-                }
-
-                auto jsonSourceMapBlob = StringBlob::moveCreate(json);
-
                 auto artifactDesc = ArtifactDesc::make(ArtifactKind::Json, ArtifactPayload::SourceMap, ArtifactStyle::Obfuscated);
 
                 // Create the source map artifact
                 auto sourceMapArtifact = Artifact::create(artifactDesc, sourceMap->m_file.getUnownedSlice());
-                sourceMapArtifact->addRepresentationUnknown(jsonSourceMapBlob);
+
+                // Add the repesentation
+                ComPtr<IObjectCastableAdapter> castableAdapter(new ObjectCastableAdapter(sourceMap));
+                sourceMapArtifact->addRepresentation(castableAdapter);
 
                 // Associate with the container
                 m_containerArtifact->addAssociated(sourceMapArtifact);
diff --git a/source/slang/slang-emit.cpp b/source/slang/slang-emit.cpp
index e2948561c..67a4c4610 100644
--- a/source/slang/slang-emit.cpp
+++ b/source/slang/slang-emit.cpp
@@ -82,7 +82,7 @@
 #include "../compiler-core/slang-artifact-impl.h"
 #include "../compiler-core/slang-artifact-associated-impl.h"
 
-#include "../compiler-core/slang-json-source-map-util.h"
+#include "../core/slang-castable.h"
 
 #include <assert.h>
 
@@ -1152,28 +1152,10 @@ SlangResult CodeGenContext::emitEntryPointsSourceFromIR(ComPtr<IArtifact>& outAr
 
     if (sourceMap)
     {
-        SourceManager sourceMapSourceManager;
-        sourceMapSourceManager.initialize(nullptr, nullptr);
-
-        // Create a sink
-        DiagnosticSink sourceMapSink(&sourceMapSourceManager, nullptr);
-
-        // Turn into JSON
-        RefPtr<JSONContainer> jsonContainer(new JSONContainer(&sourceMapSourceManager));
-
-        JSONValue jsonValue;
-        SLANG_RETURN_ON_FAIL(JSONSourceMapUtil::encode(sourceMap, jsonContainer, &sourceMapSink, jsonValue));
-
-        // Okay now convert this into a text file and then a blob
-
-        // Convert into a string
-        JSONWriter writer(JSONWriter::IndentationStyle::KNR);
-        jsonContainer->traverseRecursively(jsonValue, &writer);
-
-        auto sourceMapBlob = StringBlob::moveCreate(writer.getBuilder());
-
         auto sourceMapArtifact = ArtifactUtil::createArtifact(ArtifactDesc::make(ArtifactKind::Json, ArtifactPayload::SourceMap, ArtifactStyle::None));
-        sourceMapArtifact->addRepresentationUnknown(sourceMapBlob);
+
+        ComPtr<IObjectCastableAdapter> castableAdapter(new ObjectCastableAdapter(sourceMap));
+        sourceMapArtifact->addRepresentation(castableAdapter);
 
         artifact->addAssociated(sourceMapArtifact);
     }
diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index c8cda0dca..bedfb1161 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -15,8 +15,6 @@
 #include "../compiler-core/slang-artifact-associated-impl.h"
 #include "../compiler-core/slang-artifact-container-util.h"
 
-#include "../compiler-core/slang-json-source-map-util.h"
-
 #include "../core/slang-memory-file-system.h"
 
 #include "slang-module-library.h"
@@ -4884,12 +4882,11 @@ SlangResult _addLibraryReference(EndToEndCompileRequest* req, IArtifact* artifac
                 isDerivedFrom(assocDesc.payload, ArtifactPayload::SourceMap) &&
                 isDerivedFrom(assocDesc.style, ArtifactStyle::Obfuscated))
             {
-                ComPtr<ISlangBlob> sourceMapBlob;
-                SLANG_RETURN_ON_FAIL(associated->loadBlob(ArtifactKeep::No, sourceMapBlob.writeRef()));
+                ComPtr<ICastable> castable;
+                SLANG_RETURN_ON_FAIL(associated->getOrCreateRepresentation(SourceMap::getTypeGuid(), ArtifactKeep::Yes, castable.writeRef()));
+
+                auto sourceMap = as<SourceMap>(castable);
 
-                RefPtr<SourceMap> sourceMap;
-                SLANG_RETURN_ON_FAIL(JSONSourceMapUtil::read(sourceMapBlob, nullptr, sourceMap));
-                
                 // I guess we add to all ir modules?
 
                 for (auto irModule : library->m_modules)