Runtime execution of Visual Studio Compiler (#978)

* 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.

1 files changed, 61 insertions, 0 deletions

diff --git a/source/core/slang-process-util.h b/source/core/slang-process-util.h
new file mode 100644
index 000000000..19ae7c0d1
--- /dev/null
+++ b/source/core/slang-process-util.h
@@ -0,0 +1,61 @@
+// slang-process-util.h
+#ifndef SLANG_PROCESS_UTIL_H
+#define SLANG_PROCESS_UTIL_H
+
+#include "slang-string.h"
+#include "slang-list.h"
+
+namespace Slang {
+
+struct CommandLine
+{
+    enum class ExecutableType
+    {
+        Unknown,                    ///< The executable is not specified 
+        Path,                       ///< The executable is set as a path
+        Filename,                   ///< The executable is set as a filename
+    };
+
+    void addArg(const String& in) { m_args.add(in); }
+    void addArgs(const String* args, Int argsCount) { m_args.addRange(args, argsCount); }
+    void setExecutablePath(const String& path) { m_executableType = ExecutableType::Path; m_executable = path; }
+    void setExecutableFilename(const String& filename) { m_executableType = ExecutableType::Filename; m_executable = filename; }
+
+        /// Ctor
+    CommandLine():m_executableType(ExecutableType::Unknown) {}
+
+    ExecutableType m_executableType;    ///< How the executable is specified
+    String m_executable;                ///< Executable to run 
+    List<String> m_args;          ///< The parameters to pass 
+};
+
+struct ExecuteResult
+{
+    void init()
+    {
+        resultCode = 0;
+        standardOutput = String();
+        standardError = String();
+    }
+
+    typedef int ResultCode;
+    ResultCode resultCode;
+    Slang::String standardOutput;
+    Slang::String standardError;
+};
+
+struct ProcessUtil
+{
+        /// Get the suffix used on this platform
+    static UnownedStringSlice getExecutableSuffix();
+
+        /// Output how the command line is executed on the target (with escaping and the such like)
+    static String getCommandLineString(const CommandLine& commandLine);
+
+        /// Execute the command line 
+    static SlangResult execute(const CommandLine& commandLine, ExecuteResult& outExecuteResult);
+};
+
+}
+
+#endif // SLANG_PROCESS_UTIL_H