CommandLine arg escaping (#980)

* 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.

2 files changed, 15 insertions, 67 deletions

diff --git a/source/core/windows/slang-win-process-util.cpp b/source/core/windows/slang-win-process-util.cpp
index 680864acb..ac6468109 100644
--- a/source/core/windows/slang-win-process-util.cpp
+++ b/source/core/windows/slang-win-process-util.cpp
@@ -154,35 +154,7 @@ static DWORD WINAPI _readerThreadProc(LPVOID threadParam)
     return UnownedStringSlice::fromLiteral(".exe");
 }
 
-static bool _isLetter(char c)
-{
-    return (c >= 'a' && c <= 'z') || (c >= 'A' && c <= 'Z');
-}
-
-/* Special case handling for command line switches of the form /LINKPATH: that it is immediately followed
-potentially by a path. This detects that kind of switch, and returns the index of the first character after
-the :. If doesn't have the right format returns -1, to indicate that it's not this style of switch */
-static int _calcIndexOfColonSwitch(const UnownedStringSlice& slice)
-{
-    if (!slice.startsWith("/"))
-    {
-        return -1;
-    }
-    int index = slice.indexOf(':');
-    if (index > 0)
-    {
-        for (int i = 1; i < index; ++i)
-        {
-            if (!_isLetter(slice[i]))
-            {
-                return -1;
-            }
-        }
-    }
-    return index + 1;
-}
-
-static void _appendCommandLineEscaped(const UnownedStringSlice& slice, StringBuilder& out)
+/* static */void ProcessUtil::appendCommandLineEscaped(const UnownedStringSlice& slice, StringBuilder& out)
 {
     // TODO(JS): This escaping is not complete... !
 
@@ -218,23 +190,6 @@ static void _appendCommandLineEscaped(const UnownedStringSlice& slice, StringBui
     }
 }
 
-/* static */void ProcessUtil::appendCommandLineEscaped(const UnownedStringSlice& slice, StringBuilder& out)
-{
-    // Check if starts with a colon ending switch, as we need to special case escaping in this case
-    const int index = _calcIndexOfColonSwitch(slice);
-    if (index >= 0)
-    {
-        // Append the switch prefix as is (ie /linkpath:)
-        out << UnownedStringSlice(slice.begin(), index);
-        // Append the stuff after the prefix escaping if needed
-        _appendCommandLineEscaped(UnownedStringSlice(slice.begin() + index, slice.end()), out);
-    }
-    else
-    {
-        _appendCommandLineEscaped(slice, out);
-    } 
-}
-
 /* static */String ProcessUtil::getCommandLineString(const CommandLine& commandLine)
 {
     StringBuilder cmd;
@@ -242,7 +197,14 @@ static void _appendCommandLineEscaped(const UnownedStringSlice& slice, StringBui
     for (const auto& arg : commandLine.m_args)
     {
         cmd << " ";
-        appendCommandLineEscaped(arg.getUnownedSlice(), cmd);
+        if (arg.type == CommandLine::ArgType::Unescaped)
+        {
+            appendCommandLineEscaped(arg.value.getUnownedSlice(), cmd);
+        }
+        else
+        {
+            cmd << arg.value;
+        }
     }
     return cmd.ToString();
 }
diff --git a/source/core/windows/slang-win-visual-studio-util.cpp b/source/core/windows/slang-win-visual-studio-util.cpp
index 5fc56d091..b7de7607c 100644
--- a/source/core/windows/slang-win-visual-studio-util.cpp
+++ b/source/core/windows/slang-win-visual-studio-util.cpp
@@ -373,9 +373,7 @@ static SlangResult _find(int versionIndex, WinVisualStudioUtil::VersionPath& out
     // /Fd - followed by name of the pdb file
     if (options.debugInfoType != DebugInfoType::None)
     {
-        StringBuilder builder;
-        builder << "/Fd" << options.modulePath << ".pdb";
-        cmdLine.addArg(builder);
+        cmdLine.addPrefixPathArg("/Fd", options.modulePath, ".pdb");
     }
     
     switch (options.targetType)
@@ -392,28 +390,20 @@ static SlangResult _find(int versionIndex, WinVisualStudioUtil::VersionPath& out
                 cmdLine.addArg("/LD");
             }
 
-            StringBuilder builder;
-            builder << "/Fe" << options.modulePath << ".dll";
-            cmdLine.addArg(builder);
+            cmdLine.addPrefixPathArg("/Fe", options.modulePath, ".dll");
             break;
         }
         case TargetType::Executable:
         {
-            StringBuilder builder;
-            builder << "/Fe" << options.modulePath << ".exe";
-            cmdLine.addArg(builder);
+            cmdLine.addPrefixPathArg("/Fe", options.modulePath, ".exe");
             break;
         }
         default: break;
     }
 
     // Object file specify it's location - needed if we are out
-    {
-        StringBuilder builder;
-        builder << "/Fo" << options.modulePath << ".obj";
-        cmdLine.addArg(builder);
-    }
-
+    cmdLine.addPrefixPathArg("/Fo", options.modulePath, ".obj");
+    
     // Add defines
     for (const auto& define : options.defines)
     {
@@ -434,7 +424,6 @@ static SlangResult _find(int versionIndex, WinVisualStudioUtil::VersionPath& out
         cmdLine.addArg(include);
     }
 
-    
     // https://docs.microsoft.com/en-us/cpp/build/reference/eh-exception-handling-model?view=vs-2019
     // /Eha - Specifies the model of exception handling. (a, s, c, r are options)
 
@@ -450,10 +439,7 @@ static SlangResult _find(int versionIndex, WinVisualStudioUtil::VersionPath& out
     for (const auto& libPath : options.libraryPaths)
     {
         // Note that any escaping of the path is handled in the ProcessUtil::
-        StringBuilder builder;
-        builder << "/LIBPATH:" << libPath;
-
-        cmdLine.addArg(builder);
+        cmdLine.addPrefixPathArg("/LIBPATH:", libPath);
     }
 }