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, 42 insertions, 0 deletions

diff --git a/source/core/slang-string-util.cpp b/source/core/slang-string-util.cpp
index 11d6846f0..e571bbc99 100644
--- a/source/core/slang-string-util.cpp
+++ b/source/core/slang-string-util.cpp
@@ -199,6 +199,48 @@ ComPtr<ISlangBlob> StringUtil::createStringBlob(const String& string)
     return (fromChar == toChar || string.indexOf(fromChar) == Index(-1)) ? string : calcCharReplaced(string.getUnownedSlice(), fromChar, toChar);
 }
 
+/* static */void StringUtil::calcLines(const UnownedStringSlice& textIn, List<UnownedStringSlice>& outLines)
+{
+    char const* begin = textIn.begin();
+    char const* end = textIn.end();
+
+    char const* cursor = begin;
 
+    const char* lineStart = cursor;
+
+    while (cursor < end)
+    {
+        int c = *cursor++;
+        switch (c)
+        {
+            case '\r': case '\n':
+            {
+                outLines.add(UnownedStringSlice(lineStart, cursor - 1));
+
+                // When we see a line-break character we need
+                // to record the line break, but we also need
+                // to deal with the annoying issue of encodings,
+                // where a multi-byte sequence might encode
+                // the line break.
+
+                if (cursor < end)
+                {
+                    int d = *cursor;
+                    if ((c ^ d) == ('\r' ^ '\n'))
+                        cursor++;
+                }
+                lineStart = cursor;
+                break;
+            }
+            default:
+                break;
+        }
+    }
+
+    if (cursor > lineStart)
+    {
+        outLines.add(UnownedStringSlice(lineStart, cursor));
+    }
+}
 
 } // namespace Slang