Abstract CPPCompiler (#983)

* Work in progress to be able to invoke VS from within code.

* First pass at windows version of refactor of OSProcessSpawner

* Closer to getting VS path lookup working.

* Make OSString assignable/ctor able

* Work out program files directory directly, so don't have to expand %%.

* WIP: Improve handling of process spawning.

* Add support for splitting input by line.

* * Correctly locates visual studio install
* Added functionality to invoke vs via cmd

* Add option to execute the command line.

* Handle in ProcessUtil for windows -> WinHandle.

* Rename files slang-win-visual-studio-util.cpp/.h and slang-process-util.h

* First pass at unix/linux version of ProcessUtil.

* Fix reading Visual Studio path from the registry.

* Get compiling on linux with.

* Fix vcvarsall.bat name

* Use ProcessUtil to execute external code.

* Remove OSProcessSpawner.

* Remove includes for "os.h" where no longer needed.

* Fix tabbing issue in premake5.lua
Remove test code from slang-test-main.cpp

* Fix premake4.lua tabbing issue.

* Small fixes to slang-process-util.h
Init ExecuteResult on Win execute.

* Improve comments.

* Fix bug in StringUtil::calcLines - with oddly terminated source input being able to read past end.
Make slang-generate use StringUtil over it's own impl.

* Fix off by one bug in working out Visual Studio version.

* Fix bug in calculating Visual Studio Version

* Fix compilation on linux with string parameter being passed to messageFormat.

* Remove erroneous use of kOSError codes - use Result.

* First effort to generate standard compiler options.

* Initial efforts in compiling source code in test framework for VisualStudio.

* Testing compiling c code on VisualStudio on Windows.

* Fix warning on linux.

* Fix clang on linux warning (and therefore failing) returning a StringBuilder as String.

* Disable return-std-move on clang.

* CommandLine arguments are now tagged if they are escaped or not. That it is the clients responsibility to escape command lines that cannot be automatically escaped.

* Add checks on unix/linux that command line args are all unescaped.

* WIP getting runtime GCC to work.

* First pass compiler working on unix-like targets.

* Added File::remove function.

* Enable c-compile.c test on 'smoke'.

* WIP abstracting the CPP compiler concept.

* CPPCompilerSet and CPPCompilerUtil working on windows. Problem on unix.

* Used stdError for parsing of invoke of compiler to figure out verison.

* Removed some code that was no longer needed from slang-cpp-compiler.cpp

3 files changed, 26 insertions, 25 deletions

diff --git a/tools/slang-test/slang-test-main.cpp b/tools/slang-test/slang-test-main.cpp
index b93833f89..fdd5cd13d 100644
--- a/tools/slang-test/slang-test-main.cpp
+++ b/tools/slang-test/slang-test-main.cpp
@@ -1094,6 +1094,14 @@ String getExpectedOutput(String const& outputStem)
 
 static TestResult runExecuteC(TestContext* context, TestInput& input)
 {
+    CPPCompilerSet* compilerSet = context->getCPPCompilerSet();
+    CPPCompiler* compiler = compilerSet ? compilerSet->getDefaultCompiler() : nullptr;
+
+    if (!compiler)
+    {
+        return TestResult::Ignored;
+    }
+
     // If we are just collecting requirements, say it passed
     if (context->isCollectingRequirements())
     {
@@ -1112,7 +1120,7 @@ static TestResult runExecuteC(TestContext* context, TestInput& input)
 
     String modulePath = Path::combine(directory, moduleName);
 
-    CPPCompileOptions options;
+    CPPCompiler::CompileOptions options;
 
     // Compile this source
     options.sourceFiles.add(filePath);
@@ -1120,33 +1128,10 @@ static TestResult runExecuteC(TestContext* context, TestInput& input)
 
     ExecuteResult exeRes;
 
-#ifdef _WIN32
-    // Find
-    List<WinVisualStudioUtil::VersionPath> versionPaths;
-    WinVisualStudioUtil::find(versionPaths);
-
-    // Didn't find the visual studio compiler
-    if (versionPaths.getCount() <= 0)
-    {
-        return TestResult::Ignored;
-    }
-
-    CommandLine cmdLine;
-    WinVisualStudioUtil::calcArgs(options, cmdLine);
-
-    if (SLANG_FAILED(WinVisualStudioUtil::executeCompiler(versionPaths[0], cmdLine, exeRes)))
-    {
-        return TestResult::Fail;
-    }
-#else
-    CommandLine cmdLine;
-    UnixCPPCompilerUtil::calcArgs(options, cmdLine);
-
-    if (SLANG_FAILED(UnixCPPCompilerUtil::executeCompiler(cmdLine, exeRes)))
+    if (SLANG_FAILED(compiler->compile(options, exeRes)))
     {
         return TestResult::Fail;
     }
-#endif
 
     // Execute the binary and see what we get
     {
diff --git a/tools/slang-test/test-context.cpp b/tools/slang-test/test-context.cpp
index 0b17b3672..90052c4c4 100644
--- a/tools/slang-test/test-context.cpp
+++ b/tools/slang-test/test-context.cpp
@@ -90,3 +90,13 @@ void TestContext::setInnerMainFunc(const String& name, InnerMainFunc func)
         m_sharedLibTools.Add(name, tool);
     }
 }
+
+CPPCompilerSet* TestContext::getCPPCompilerSet()
+{
+    if (!cppCompilerSet)
+    {
+        cppCompilerSet = new CPPCompilerSet;
+        CPPCompilerUtil::initializeSet(cppCompilerSet);
+    }
+    return cppCompilerSet;
+}
diff --git a/tools/slang-test/test-context.h b/tools/slang-test/test-context.h
index afc5bb427..895cb9c06 100644
--- a/tools/slang-test/test-context.h
+++ b/tools/slang-test/test-context.h
@@ -9,6 +9,7 @@
 #include "../../source/core/slang-dictionary.h"
 #include "../../source/core/slang-test-tool-util.h"
 #include "../../source/core/slang-render-api-util.h"
+#include "../../source/core/slang-cpp-compiler.h"
 
 #include "options.h"
 
@@ -95,6 +96,9 @@ class TestContext
         /// If set, then tests are executed
     bool isExecuting() const { return testRequirements == nullptr; }
 
+        /// Get compiler factory
+    Slang::CPPCompilerSet* getCPPCompilerSet();
+
         /// Ctor
     TestContext();
         /// Dtor
@@ -111,6 +115,8 @@ class TestContext
     Slang::RenderApiFlags availableRenderApiFlags = 0;
     bool isAvailableRenderApiFlagsValid = false;
 
+    Slang::RefPtr<Slang::CPPCompilerSet> cppCompilerSet;
+
 protected:
     struct SharedLibraryTool
     {