Passing source to Downstream compilation as artifacts (#2382)

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

* Make DownstreamCompileOptions use POD types.

* CharSliceAllocator -> SliceAllocator
Added SliceConverter
CharSliceCaster -> SliceCaster

* First attempt at zero terminating around blobs.

* Fix clang warning.

* Add SlangTerminatedChars
Make Blob implementations support it.
Make most blobs 'terminated'.

* Fix bug setting up sourceFiles for CommandLineDownstreamCompiler.

* Traffic in TerminatedCharSlice for sourceFiles.
Use ArtifactDesc to generate temporary file names for source.

* Fix typo in testing for shared library/C++.

* Working with source being passed as artifacts to DownstreamCompiler.

* Use artifacts in SourceManager/SourceFile.

* Support infering extension from the original file extension.

1 files changed, 14 insertions, 0 deletions

diff --git a/slang.h b/slang.h
index a224bf6f6..5be05bb61 100644
--- a/slang.h
+++ b/slang.h
@@ -1085,6 +1085,14 @@ extern "C"
     The name is the name of a file system object (directory/file) in the specified path (ie it is without a path) */
     typedef void (*FileSystemContentsCallBack)(SlangPathType pathType, const char* name, void* userData);
 
+    /* Determines how paths map to files on the OS file system */
+    enum class OSPathKind : uint8_t
+    {
+        None,                ///< Paths do not map to the file system
+        Direct,              ///< Paths map directly to the file system
+        Canonical,           ///< Only canonical paths map to the file system
+    };
+
     /** An extended file system abstraction.
     
     Implementing and using this interface over ISlangFileSystem gives much more control over how paths
@@ -1200,6 +1208,12 @@ extern "C"
             const char* path,
             FileSystemContentsCallBack callback,
             void* userData) = 0;
+
+        /** Returns how paths map to the OS file system
+        
+        @returns true if this 
+        */
+        virtual SLANG_NO_THROW OSPathKind SLANG_MCALL getOSPathKind() = 0;
     };
 
     #define SLANG_UUID_ISlangFileSystemExt ISlangFileSystemExt::getTypeGuid()