Feature/source downstream compiler (#1153)

* CPPCompiler -> DownstreamCompiler

* Added DownstreamCompileResult to start abstraction such that we don't need files.

* * Split out slang-blob.cpp
* Made CompileResult hold a DownstreamCompileResult - for access to binary or ISlangSharedLibrary

* Keep temporary files in scope.

* Add a hash to the hex dump stream.

* Move all file tracking into DownstreamCompiler.

* WIP support for nvrtc.

* WIP: Adding support for nvrtc compiler.
Adding enum types, wiring up the nvrtc into slang.

* Fix remaining CPPCompiler references.

* Fix order issue on target string matching.

* Use ISlangSharedLibrary for nvrtc.

* Use DownstreamCompiler for nvrtc.

* WIP first pass at compilation win nvrtc.

* Added testing if file is on file system into CommandLineDownstreamCompiler.
Added sourceContentsPath.

* Make test cuda-compile.cu work by just compiling not comparing output.

* Genearlize DownstreamCompiler usage.

* Fix warning on clang.

* Remove CompilerType from DownstreamCompiler.

* Use DownstreamCompiler interface for all compilers.

NOTE for FXC, DXC and GLSLANG this doesn't mean using 'compile' - it's still extracting functions from shared library.

* Replace DownstreamCompiler::SourceType -> SlangSourceLanguage

* Replace _canCompile with something data driven.

* Fix compiling on gcc/clang for DownstreamCompiler.

* Moved some text conversions into DownstreamCompiler.

* Fix problem on non-vc builds with not having return on locateCompilers for VS.

* Change so no warning for code not reachable on locateCompilers for vs.

1 files changed, 7 insertions, 6 deletions

diff --git a/source/slang/slang-check.cpp b/source/slang/slang-check.cpp
index 50de73f07..b04b1c9f1 100644
--- a/source/slang/slang-check.cpp
+++ b/source/slang/slang-check.cpp
@@ -114,7 +114,7 @@ namespace Slang
 
         if (type == PassThroughMode::GenericCCpp)
         {
-            // try loading all C/C++ compilers
+            // try testing for availablilty on all C/C++ compilers
             getOrLoadDownstreamCompiler(PassThroughMode::Clang, sink);
             getOrLoadDownstreamCompiler(PassThroughMode::Gcc, sink);
             getOrLoadDownstreamCompiler(PassThroughMode::VisualStudio, sink);
@@ -138,19 +138,20 @@ namespace Slang
 
         DownstreamCompilerUtil::updateDefaults(m_downstreamCompilerSet);
 
+        DownstreamCompiler* compiler = nullptr;
+
         if (type == PassThroughMode::GenericCCpp)
         {
-            m_downstreamCompilers[int(type)] = m_downstreamCompilerSet->getDefaultCompiler(DownstreamCompiler::SourceType::CPP);
+            compiler = m_downstreamCompilerSet->getDefaultCompiler(SLANG_SOURCE_LANGUAGE_CPP);
         }
         else
         {
             DownstreamCompiler::Desc desc;
             desc.type = SlangPassThrough(type);
-
-            m_downstreamCompilers[int(type)] = DownstreamCompilerUtil::findCompiler(m_downstreamCompilerSet, DownstreamCompilerUtil::MatchType::Newest, desc);
+            compiler = DownstreamCompilerUtil::findCompiler(m_downstreamCompilerSet, DownstreamCompilerUtil::MatchType::Newest, desc);
         }
-
-        return m_downstreamCompilers[int(type)];
+        m_downstreamCompilers[int(type)] = compiler;
+        return compiler;
     }
 
     SlangFuncPtr Session::getSharedLibraryFunc(SharedLibraryFuncType type, DiagnosticSink* sink)