PersistentJSONValue (#2028)

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

* Use 'Process' to communicate with an command line tool.

* Remove slang-win-stream

* Tidy up windows ProcessUtil.

* First version of BufferedReadStream.

* Windows working IPC for steams.

* Test proxy count option.

* Split Process/ProcessUtil. Process is platform dependant. ProcessUtil are functions that are platform independent.

* First implementation of Unix Process interface.

* Unix process compiles on cygwin.

* Fix typo in unix process.

* Separate unix pipe stream error of invalid access, from pipe availability.

* Fix in standard line extraction.

* Make fd non blocking.

* Fix issues with Windows Process streams.

* Added UnixPipe.

* Some fixes around UnixPipeStream.

* Make a unix stream closed explicit.

* Hack to debug linux process/stream.

* Revert to old linux pipe handling.

* Pass executable path for unit tests.
Split out CommandLine into own source.

* Small improvements in process/command line.

* Check process behavior with crash.

* Make stderr and stdout unbuffered for crash testing.

* Only turn disable buffering in crash test.

* Disable crash test on CI.

* Fix crash on clang/linux.

* Enable crash test.
Remove _appendBuffer as can use StreamUtil functionality.

* Added inital processing for http headers.

* Small improvements to HttpHeader.

* First pass HTTPPacketConnection working on windows.

* Enable other Process communication tests.

* Update comments.

* WIP JSON RPC.

* Add terminate to Process.
Made JSONRPC a Util.

* Small tidy up around HTTPPacketConnection.

* Improve process termination options.

* WIP for test-server.

* Add diagnostics error handling to test-server.

* Improved JSON support.
Parsing/creating JSON-RPC messages.

* WIP JSONRPC parsing.

* First pass RttiInfo support.

* WIP converting between JSON/native types.

* Project files.

* Split out RttiUtil.
Made RttiInfo constuction thread safe.

* WIP RTTI<->JSON.

* Add diagnostics to JSON<->native conversions.

* Make RttiInfo for structs globals. Avoids problem around derived types (like pointers), being able to cause an abort.

* Add pointer support to RTTI.
Fixed some compilation issues on linux.

* Add fixed array support.

* Added Rtti unit test.

* Add rtti unit test.

* Split out quoted/unquoted key handling.
Fix bugs in JSON value/container.
Added JSON native test.

* Make default array allocator use malloc/free.
Remove the new[] handler (doesn't work on visuals studio).

* Fix for linux warning.

* Remove some test code.

* Fix issues on x86 win.

* Fix warning on aarch64.

* Fix some bugs in JSON parsing/handling.
Make Rtti work copy/dtor/ctor struct types.

* Testing JSON<->native with fixed array.
Make makeArrayView explicit if it's just a single value.
Added array type.

* Fix getting arrayView.

* Improve JSON diagnostic name.

* First pass refactor using Rtti for JSON RPC.

* First pass of test server using RTTI/JSON-RPC.

* Added JSONRPCConnection.

* Fix some naming issues.

* First pass of test-server working.

* Added unit test support for JSON-RPC test server.

* Fix compilation issues on linux around template handling.

* Typo fix.

* Fix a bug around SourceLoc lookup with JSONContainer.

* Set the console type to console for ISlangWriters.

* Small improvements to test-server.

* Small improvements in test-server.

* Small fix.

* Remove test-proxy. Make test-process a process that can be used to unit test 'Process'.
Adding mechanism to control spawning that will create a new process for every test.

* Ability to remove source manager for JSONValue.

* WIP SimpleJSONValue.

* Add PersistentJSONValue

* Testing around PersistentJSONValue.
Bug fixes.

* Small code improvements.

1 files changed, 69 insertions, 8 deletions

diff --git a/source/compiler-core/slang-json-value.h b/source/compiler-core/slang-json-value.h
index 2e8707a87..25e74cb36 100644
--- a/source/compiler-core/slang-json-value.h
+++ b/source/compiler-core/slang-json-value.h
@@ -50,6 +50,8 @@ struct JSONValue
         FloatValue,
         StringValue,
 
+        StringRepresentation,
+
         Array,
         Object,
 
@@ -105,14 +107,14 @@ struct JSONValue
 
     union 
     {
-        Index rangeIndex;           ///< Used for Array/Object
-        Index length;               ///< Length in bytes if it is a 'Lexeme'
-        double floatValue;          ///< Float value
-        int64_t intValue;           ///< Integer value
-        JSONKey stringKey;          ///< The pool key if it's a string
+        Index rangeIndex;                       ///< Used for Array/Object
+        Index length;                           ///< Length in bytes if it is a 'Lexeme'
+        double floatValue;                      ///< Float value
+        int64_t intValue;                       ///< Integer value
+        JSONKey stringKey;                      ///< The pool key if it's a string
+        StringRepresentation* stringRep;        ///< Only ever used on a 'PersistentJSONValue'
     };
 
-
     static const Kind g_typeToKind[Index(Type::CountOf)];
 
     static const OtherRttiInfo g_rttiInfo;
@@ -145,6 +147,65 @@ struct JSONKeyValue
     static JSONKeyValue g_invalid;
 };
 
+class JSONContainer;
+
+/* Is similar to JSONValue, but is designed to
+
+* Only be able to hold 'Simple' types (ie not array/object)
+* Does not reference/require JSONContainer.
+
+Not requiring JSONContainer means it's useful to hold state when JSONContainer goes out of scope.
+Care may need to be taken if sourceManager goes out of scope, sourceLocs may become invalid. This
+is true of a regular JSONValue.
+
+Care must also be taken because it is derived from JSONValue. It *can* be sliced and work correctly,
+but *requires* that the PersistentJSONValue with same value to stay in scope in general. In practice
+this is only an issue with StringRepresention type.
+*/
+class PersistentJSONValue : public JSONValue
+{
+public:
+    typedef JSONValue Super;
+    typedef PersistentJSONValue ThisType;
+
+        /// If it's a string type this will always work
+    String getString() const;
+    UnownedStringSlice getSlice() const;
+
+        /// Set to the value
+    void set(const JSONValue& in, JSONContainer* container);
+        /// Set directly to a string
+    void set(const UnownedStringSlice& slice, SourceLoc loc);
+
+        /// True if identical
+    bool operator==(const ThisType& rhs) const;
+    bool operator!=(const ThisType& rhs) const { return !(*this == rhs); }
+
+        /// Assignable
+    void operator=(const ThisType& rhs);
+
+    PersistentJSONValue(const JSONValue& in, JSONContainer* container) { _init(in, container); }
+    PersistentJSONValue(const JSONValue& in, JSONContainer* container, SourceLoc inLoc) { _init(in, container); loc = inLoc; }
+
+        /// Copy Ctor
+    PersistentJSONValue(const ThisType& rhs);
+        /// Default Ctor (will be set to invalid)
+    PersistentJSONValue() {}
+
+    
+    ~PersistentJSONValue()
+    {
+        if (type == Type::StringRepresentation && stringRep)
+        {
+            stringRep->releaseReference();
+        }
+    }
+protected:
+        /// Assumes this has no valid data
+    void _init(const JSONValue& in, JSONContainer* container);
+    void _init(const UnownedStringSlice& slice, SourceLoc loc);
+};
+
 class JSONContainer : public RefObject
 {
 public:
@@ -170,7 +231,7 @@ public:
 
         /// Returns the index of key in obj, or -1 if not found
     Index findObjectIndex(const JSONValue& obj, JSONKey key) const;
-        /// Get the value in the object at key. REturns invalid if not found.
+        /// Get the value in the object at key. Returns invalid if not found.
     JSONValue findObjectValue(const JSONValue& obj, JSONKey key) const;
 
         /// Returns the index 
@@ -201,7 +262,7 @@ public:
         /// Get as a string. The contents will stay in scope as long as the container
     UnownedStringSlice getString(const JSONValue& in);
 
-    /// Gets the lexeme
+        /// Gets the lexeme
     UnownedStringSlice getLexeme(const JSONValue& in);
 
         /// Get a key for a name