Parsing CPP Compiler output (#994)

* Added extractLine line parsing to StringUtil. Use for matching lines instead of calcLines. calcLines uses extractLine to extract lines.
Fixed problems found in output of some tests- due to how a how final line is handled. Now a final line has a \r or \n\r combination, but nothing else after it, it is considered the last line (not the line after it).

* Use StringUtil::extractLine in slang-generate.

* Improved comment on extractLine

* Remove test code from StringUtil::extractLine

* Made StringUtil::extractLine act as if line terminators are 'separators'.
Added unit-test-string.cpp - to check behavior.

* Adding LineParser - not entirely necessary, but slightly easier to use.

* Hack to output start of tests.

* WIP parsing CPPCompiler output.

* Make extractLine return a bool.

* First attempt at Visual Studio output parsing.

* Add handling for checking error returning from CPPCompiler.

* First pass parsing output of Gcc/Clang.

* Split out VisualStudioCompilerUtil and GCCCompilerUtil.
Simplified parsing of versions.

* Simplify CPPCompiler::Output interface.

* Fix problem with cpp-compiler on linux targets.

* Add shared library link error.

* Improving GCC/Clang parsing output.

* Make cpp compiler parsing function able to return a SlangResult.

* Handling for 'info' on clang

* Add expected result for c-compile-shared-library-error.c

* * Add flags such that link errors on shared libraries are supported.
* Added StringUtil::join

* Turn off the link shared library unfound symbol option on MacOS because it causes an error (and it's not needed on that target).

* Add natvis inclusion back to visual studio projects.

* Display message to try and determine crash problem on travisbuild.

* Fix bug in handling continuations for clang.
Disabled output of exception text.

* WIP: See what clang is outputting that is parsing incorrectly on travis.

* More handling for travis clang parsing issue.

* Restore natvis to core.vcxproj

* Fix visual studio project such that it still as natvis.

14 files changed, 1137 insertions, 338 deletions

diff --git a/source/core/core.vcxproj b/source/core/core.vcxproj
index dd2f3c144..9238cf058 100644
--- a/source/core/core.vcxproj
+++ b/source/core/core.vcxproj
@@ -180,6 +180,7 @@
     <ClInclude Include="slang-dictionary.h" />
     <ClInclude Include="slang-exception.h" />
     <ClInclude Include="slang-free-list.h" />
+    <ClInclude Include="slang-gcc-compiler-util.h" />
     <ClInclude Include="slang-hash.h" />
     <ClInclude Include="slang-io.h" />
     <ClInclude Include="slang-list.h" />
@@ -203,6 +204,7 @@
     <ClInclude Include="slang-token-reader.h" />
     <ClInclude Include="slang-type-traits.h" />
     <ClInclude Include="slang-uint-set.h" />
+    <ClInclude Include="slang-visual-studio-compiler-util.h" />
     <ClInclude Include="slang-writer.h" />
     <ClInclude Include="windows\slang-win-visual-studio-util.h" />
   </ItemGroup>
@@ -210,6 +212,7 @@
     <ClCompile Include="slang-byte-encode-util.cpp" />
     <ClCompile Include="slang-cpp-compiler.cpp" />
     <ClCompile Include="slang-free-list.cpp" />
+    <ClCompile Include="slang-gcc-compiler-util.cpp" />
     <ClCompile Include="slang-io.cpp" />
     <ClCompile Include="slang-memory-arena.cpp" />
     <ClCompile Include="slang-object-scope-manager.cpp" />
@@ -226,6 +229,7 @@
     <ClCompile Include="slang-text-io.cpp" />
     <ClCompile Include="slang-token-reader.cpp" />
     <ClCompile Include="slang-uint-set.cpp" />
+    <ClCompile Include="slang-visual-studio-compiler-util.cpp" />
     <ClCompile Include="slang-writer.cpp" />
     <ClCompile Include="windows\slang-win-process-util.cpp" />
     <ClCompile Include="windows\slang-win-visual-studio-util.cpp" />
diff --git a/source/core/core.vcxproj.filters b/source/core/core.vcxproj.filters
index 8d7add8ea..3b3e429ba 100644
--- a/source/core/core.vcxproj.filters
+++ b/source/core/core.vcxproj.filters
@@ -39,6 +39,9 @@
     <ClInclude Include="slang-free-list.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="slang-gcc-compiler-util.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="slang-hash.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -108,6 +111,9 @@
     <ClInclude Include="slang-uint-set.h">
       <Filter>Header Files</Filter>
     </ClInclude>
+    <ClInclude Include="slang-visual-studio-compiler-util.h">
+      <Filter>Header Files</Filter>
+    </ClInclude>
     <ClInclude Include="slang-writer.h">
       <Filter>Header Files</Filter>
     </ClInclude>
@@ -125,6 +131,9 @@
     <ClCompile Include="slang-free-list.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="slang-gcc-compiler-util.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="slang-io.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
@@ -173,6 +182,9 @@
     <ClCompile Include="slang-uint-set.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
+    <ClCompile Include="slang-visual-studio-compiler-util.cpp">
+      <Filter>Source Files</Filter>
+    </ClCompile>
     <ClCompile Include="slang-writer.cpp">
       <Filter>Source Files</Filter>
     </ClCompile>
diff --git a/source/core/slang-cpp-compiler.cpp b/source/core/slang-cpp-compiler.cpp
index 18cb9cdae..0ed0a1ba8 100644
--- a/source/core/slang-cpp-compiler.cpp
+++ b/source/core/slang-cpp-compiler.cpp
@@ -8,374 +8,167 @@
 #include "slang-io.h"
 #include "slang-shared-library.h"
 
+// if Visual Studio import the visual studio platform specific header
 #if SLANG_VC
 #   include "windows/slang-win-visual-studio-util.h"
 #endif
 
+#include "slang-visual-studio-compiler-util.h"
+#include "slang-gcc-compiler-util.h"
+
 namespace Slang
 {
 
-/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! GenericCPPCompiler !!!!!!!!!!!!!!!!!!!!!!*/
+/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CPPCompiler::OutputMessage !!!!!!!!!!!!!!!!!!!!!!*/
 
-SlangResult GenericCPPCompiler::compile(const CompileOptions& options, ExecuteResult& outResult)
+/* static */UnownedStringSlice CPPCompiler::OutputMessage::getTypeText(OutputMessage::Type type)
 {
-    // Copy the command line options
-    CommandLine cmdLine(m_cmdLine);
-
-    // Append command line args to the end of cmdLine using the target specific function for the specified options
-    m_func(options, cmdLine);
-
-#if 0
-    // Test
-    {
-        String line = ProcessUtil::getCommandLineString(cmdLine);
-        printf("%s", line.getBuffer());
-    }
-#endif
-
-    SlangResult res = ProcessUtil::execute(cmdLine, outResult);
-
-#if 0
+    typedef OutputMessage::Type Type;
+    switch (type)
     {
-        printf("stdout=\"%s\"\nstderr=\"%s\"\nret=%d\n", outResult.standardOutput.getBuffer(), outResult.standardError.getBuffer(), int(outResult.resultCode));
+        default:            return UnownedStringSlice::fromLiteral("Unknown");
+        case Type::Info:    return UnownedStringSlice::fromLiteral("Info");
+        case Type::Warning: return UnownedStringSlice::fromLiteral("Warning");
+        case Type::Error:   return UnownedStringSlice::fromLiteral("Error");
     }
-#endif
-
-    return res;
 }
 
-/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CPPCompilerUtil !!!!!!!!!!!!!!!!!!!!!!*/
 
-static bool _isDigit(char c)
-{
-    return c >= '0' && c <= '9';
-}
+/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CPPCompiler::Output !!!!!!!!!!!!!!!!!!!!!!*/
 
-static bool _isWhiteSpace(char c)
+Index CPPCompiler::Output::getCountByType(OutputMessage::Type type) const
 {
-    return c == ' ' || c == '\t' || c == '\n' || c == '\r';
-}
-
-/* static */SlangResult CPPCompilerUtil::parseGCCFamilyVersion(const UnownedStringSlice& text, const UnownedStringSlice& prefix, CPPCompiler::Desc& outDesc)
-{
-    List<UnownedStringSlice> lines;
-    StringUtil::calcLines(text, lines);
-
-    for (auto line : lines)
+    Index count = 0;
+    for (const auto& msg : messages)
     {
-        // TODO(JS): Ugh - having to turn into a string to do this test isn't great.
-        if (String(line).startsWith(prefix))
-        {
-            UnownedStringSlice versionSlice(line.begin() + prefix.size(), line.end());
-
-            List<Int> digits;
-
-            const char* cur = versionSlice.begin();
-            const char* end = versionSlice.end();
-
-            // Consume white space
-            while (cur < end && _isWhiteSpace(*cur)) cur++;
-
-            // Version is in format 0.0.0 
-            while (true)
-            {
-                Int value = 0;
-                const char* start = cur;
-                while (cur < end && _isDigit(*cur))
-                {
-                    value = value * 10 + (*cur - '0');
-                    cur++;
-                }
-
-                if (cur <= start)
-                {
-                    break;
-                }
-
-                digits.add(value);
-
-                if (cur < end && *cur == '.')
-                {
-                    cur++;
-                }
-            }
-
-            if (digits.getCount() < 2)
-            {
-                return SLANG_FAIL;
-            }
-
-            outDesc.majorVersion = digits[0];
-            outDesc.minorVersion = digits[1];
-            return SLANG_OK;
-        }
+        count += Index(msg.type == type);
     }
-
-    return SLANG_FAIL;
+    return count;
 }
 
-SlangResult CPPCompilerUtil::calcGCCFamilyVersion(const String& exeName, CPPCompiler::Desc& outDesc)
+Int CPPCompiler::Output::countByStage(OutputMessage::Stage stage, Index counts[Int(OutputMessage::Type::CountOf)]) const
 {
-    CommandLine cmdLine;
-    cmdLine.setExecutableFilename(exeName);
-    cmdLine.addArg("-v");
-
-    ExecuteResult exeRes;
-    SLANG_RETURN_ON_FAIL(ProcessUtil::execute(cmdLine, exeRes));
-
-    const UnownedStringSlice prefixes[] =
-    {
-        UnownedStringSlice::fromLiteral("clang version"),
-        UnownedStringSlice::fromLiteral("gcc version"),
-        UnownedStringSlice::fromLiteral("Apple LLVM version"),
-    };
-    const CPPCompiler::Type types[] =
+    Int count = 0;
+    ::memset(counts, 0, sizeof(Index) * Int(OutputMessage::Type::CountOf));
+    for (const auto& msg : messages)
     {
-        CPPCompiler::Type::Clang,
-        CPPCompiler::Type::GCC,
-        CPPCompiler::Type::Clang,
-    };
-
-    SLANG_COMPILE_TIME_ASSERT(SLANG_COUNT_OF(prefixes) == SLANG_COUNT_OF(types));
-
-    for (Index i = 0; i < SLANG_COUNT_OF(prefixes); ++i)
-    {
-        // Set the type
-        outDesc.type = types[i];
-        // Extract the version
-        if (SLANG_SUCCEEDED(parseGCCFamilyVersion(exeRes.standardError.getUnownedSlice(), prefixes[i], outDesc)))
+        if (msg.stage == stage)
         {
-            return SLANG_OK;
+            count++;
+            counts[Index(msg.type)]++;
         }
     }
-    return SLANG_FAIL;
+    return count++;
 }
 
-/* static */void CPPCompilerUtil::calcVisualStudioArgs(const CompileOptions& options, CommandLine& cmdLine)
+static void _appendCounts(const Index counts[Int(CPPCompiler::OutputMessage::Type::CountOf)], StringBuilder& out)
 {
-    // https://docs.microsoft.com/en-us/cpp/build/reference/compiler-options-listed-alphabetically?view=vs-2019
-
-    cmdLine.addArg("/nologo");
-    // Generate complete debugging information
-    cmdLine.addArg("/Zi");
-    // Display full path of source files in diagnostics
-    cmdLine.addArg("/FC");
+    typedef CPPCompiler::OutputMessage::Type Type;
 
-    if (options.flags & CompileOptions::Flag::EnableExceptionHandling)
+    for (Index i = 0; i < Int(Type::CountOf); i++)
     {
-        if (options.sourceType == SourceType::CPP)
+        if (counts[i] > 0)
         {
-            // https://docs.microsoft.com/en-us/cpp/build/reference/eh-exception-handling-model?view=vs-2019
-            // Assumes c functions cannot throw
-            cmdLine.addArg("/EHsc");
+            out << CPPCompiler::OutputMessage::getTypeText(Type(i)) << "(" << counts[i] << ") ";
         }
     }
+}
 
-    switch (options.optimizationLevel)
-    {
-        case OptimizationLevel::Debug:
-        {
-            // No optimization
-            cmdLine.addArg("/Od");
-
-            cmdLine.addArg("/MDd");
-            break;
-        }
-        case OptimizationLevel::Normal:
-        {
-            cmdLine.addArg("/O2");
-            // Multithreaded DLL
-            cmdLine.addArg("/MD");
-            break;
-        }
-        default: break;
-    }
-
-    // /Fd - followed by name of the pdb file
-    if (options.debugInfoType != DebugInfoType::None)
-    {
-        cmdLine.addPrefixPathArg("/Fd", options.modulePath, ".pdb");
-    }
-
-    switch (options.targetType)
+static void _appendSimplified(const Index counts[Int(CPPCompiler::OutputMessage::Type::CountOf)], StringBuilder& out)
+{
+    typedef CPPCompiler::OutputMessage::Type Type;
+    for (Index i = 0; i < Int(Type::CountOf); i++)
     {
-        case TargetType::SharedLibrary:
+        if (counts[i] > 0)
         {
-            // Create dynamic link library
-            if (options.optimizationLevel == OptimizationLevel::Debug)
-            {
-                cmdLine.addArg("/LDd");
-            }
-            else
-            {
-                cmdLine.addArg("/LD");
-            }
-
-            cmdLine.addPrefixPathArg("/Fe", options.modulePath, ".dll");
-            break;
+            out << CPPCompiler::OutputMessage::getTypeText(Type(i)) << " ";
         }
-        case TargetType::Executable:
-        {
-            cmdLine.addPrefixPathArg("/Fe", options.modulePath, ".exe");
-            break;
-        }
-        default: break;
     }
+}
 
-    // Object file specify it's location - needed if we are out
-    cmdLine.addPrefixPathArg("/Fo", options.modulePath, ".obj");
-
-    // Add defines
-    for (const auto& define : options.defines)
+void CPPCompiler::Output::appendSummary(StringBuilder& out) const
+{
+    Index counts[Int(OutputMessage::Type::CountOf)];
+    if (countByStage(OutputMessage::Stage::Compile, counts) > 0)
     {
-        StringBuilder builder;
-        builder << define.nameWithSig;
-        if (define.value.getLength())
-        {
-            builder << "=" << define.value;
-        }
-
-        cmdLine.addArg(builder);
+        out << "Compile: ";
+        _appendCounts(counts, out);
+        out << "\n";
     }
-
-    // Add includes
-    for (const auto& include : options.includePaths)
+    if (countByStage(OutputMessage::Stage::Link, counts) > 0)
     {
-        cmdLine.addArg("/I");
-        cmdLine.addArg(include);
+        out << "Link: ";
+        _appendCounts(counts, out);
+        out << "\n";
     }
+}
 
-    // 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)
-
-    // Files to compile
-    for (const auto& sourceFile : options.sourceFiles)
+void CPPCompiler::Output::appendSimplifiedSummary(StringBuilder& out) const
+{
+    Index counts[Int(OutputMessage::Type::CountOf)];
+    if (countByStage(OutputMessage::Stage::Compile, counts) > 0)
     {
-        cmdLine.addArg(sourceFile);
+        out << "Compile: ";
+        _appendSimplified(counts, out);
+        out << "\n";
     }
-
-    // Link options (parameters past /link go to linker)
-    cmdLine.addArg("/link");
-
-    for (const auto& libPath : options.libraryPaths)
+    if (countByStage(OutputMessage::Stage::Link, counts) > 0)
     {
-        // Note that any escaping of the path is handled in the ProcessUtil::
-        cmdLine.addPrefixPathArg("/LIBPATH:", libPath);
+        out << "Link: ";
+        _appendSimplified(counts, out);
+        out << "\n";
     }
 }
 
-/* static */void CPPCompilerUtil::calcGCCFamilyArgs(const CompileOptions& options, CommandLine& cmdLine)
+void CPPCompiler::Output::removeByType(OutputMessage::Type type)
 {
-    cmdLine.addArg("-fvisibility=hidden");
-    // Use shared libraries
-    //cmdLine.addArg("-shared");
-
-    switch (options.optimizationLevel)
+    Index count = messages.getCount();
+    for (Index i = 0; i < count; ++i)
     {
-        case OptimizationLevel::Debug:
-        {
-            // No optimization
-            cmdLine.addArg("-O0");
-            break;
-        }
-        case OptimizationLevel::Normal:
+        if (messages[i].type == type)
         {
-            cmdLine.addArg("-Os");
-            break;
+            messages.removeAt(i);
+            i--;
+            count--;
         }
-        default: break;
     }
+}
 
-    if (options.debugInfoType != DebugInfoType::None)
-    {
-        cmdLine.addArg("-g");
-    }
-
-    switch (options.targetType)
-    {
-        case TargetType::SharedLibrary:
-        {
-            // Shared library
-            cmdLine.addArg("-shared");
-            // Position independent
-            cmdLine.addArg("-fPIC");
-
-            String sharedLibraryPath = SharedLibrary::calcPlatformPath(options.modulePath.getUnownedSlice());
-
-            cmdLine.addArg("-o");
-            cmdLine.addArg(sharedLibraryPath);
-            break;
-        }
-        case TargetType::Executable:
-        {
-            cmdLine.addArg("-o");
-
-            StringBuilder builder;
-            builder << options.modulePath;
-            builder << ProcessUtil::getExecutableSuffix();
+/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! GenericCPPCompiler !!!!!!!!!!!!!!!!!!!!!!*/
 
-            cmdLine.addArg(options.modulePath);
-            break;
-        }
-        case TargetType::Object:
-        {
-            // Don't link, just produce object file
-            cmdLine.addArg("-c");
-            break;
-        }
-        default: break;
-    }
+SlangResult GenericCPPCompiler::compile(const CompileOptions& options, Output& outOutput)
+{
+    outOutput.reset();
 
-    // Add defines
-    for (const auto& define : options.defines)
-    {
-        StringBuilder builder;
-        builder << define.nameWithSig;
-        if (define.value.getLength())
-        {
-            builder << "=" << define.value;
-        }
+    // Copy the command line options
+    CommandLine cmdLine(m_cmdLine);
 
-        cmdLine.addArg(builder);
-    }
+    // Append command line args to the end of cmdLine using the target specific function for the specified options
+    m_calcArgsFunc(options, cmdLine);
 
-    // Add includes
-    for (const auto& include : options.includePaths)
-    {
-        cmdLine.addArg("-I");
-        cmdLine.addArg(include);
-    }
+    ExecuteResult exeRes;
 
-    // Link options
-    if (0)
+#if 0
+    // Test
     {
-        StringBuilder linkOptions;
-        linkOptions << "Wl,";
-        cmdLine.addArg(linkOptions);
+        String line = ProcessUtil::getCommandLineString(cmdLine);
+        printf("%s", line.getBuffer());
     }
+#endif
 
-    // Files to compile
-    for (const auto& sourceFile : options.sourceFiles)
-    {
-        cmdLine.addArg(sourceFile);
-    }
+    SLANG_RETURN_ON_FAIL(ProcessUtil::execute(cmdLine, exeRes));
 
-    for (const auto& libPath : options.libraryPaths)
+#if 0
     {
-        // Note that any escaping of the path is handled in the ProcessUtil::
-        cmdLine.addArg("-L");
-        cmdLine.addArg(libPath);
-        cmdLine.addArg("-F");
-        cmdLine.addArg(libPath);
+        printf("stdout=\"%s\"\nstderr=\"%s\"\nret=%d\n", exeRes.standardOutput.getBuffer(), exeRes.standardError.getBuffer(), int(exeRes.resultCode));
     }
+#endif
 
-    if (options.sourceType == SourceType::CPP)
-    {
-        // Make STD libs available
-        cmdLine.addArg("-lstdc++");
-    }
+    return m_parseOutputFunc(exeRes, outOutput);
 }
 
+/* !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! CPPCompilerUtil !!!!!!!!!!!!!!!!!!!!!!*/
+
 static CPPCompiler::Desc _calcCompiledWithDesc()
 {
     CPPCompiler::Desc desc = {};
@@ -383,19 +176,19 @@ static CPPCompiler::Desc _calcCompiledWithDesc()
 #if SLANG_VC
     desc = WinVisualStudioUtil::getDesc(WinVisualStudioUtil::getCompiledVersion());
 #elif SLANG_CLANG
-    desc.type = CPPCompiler::Type::Clang;
+    desc.type = CPPCompiler::CompilerType::Clang;
     desc.majorVersion = Int(__clang_major__);
     desc.minorVersion = Int(__clang_minor__);
 #elif SLANG_SNC
-    desc.type = CPPCompiler::Type::SNC;
+    desc.type = CPPCompiler::CompilerType::SNC;
 #elif SLANG_GHS
-    desc.type = CPPCompiler::Type::GHS;
+    desc.type = CPPCompiler::CompilerType::GHS;
 #elif SLANG_GCC
-    desc.type = CPPCompiler::Type::GCC;
+    desc.type = CPPCompiler::CompilerType::GCC;
     desc.majorVersion = Int(__GNUC__);
     desc.minorVersion = Int(__GNUC_MINOR__);
 #else
-    desc.type = CPPCompiler::Type::Unknown;
+    desc.type = CPPCompiler::CompilerType::Unknown;
 #endif
 
     return desc;
@@ -418,7 +211,7 @@ const CPPCompiler::Desc& CPPCompilerUtil::getCompiledWithDesc()
 {
     Int bestIndex = -1;
 
-    const CPPCompiler::Type type = desc.type;
+    const CPPCompiler::CompilerType type = desc.type;
 
     Int maxVersionValue = 0;
     Int minVersionDiff = 0x7fffffff;
@@ -488,10 +281,10 @@ const CPPCompiler::Desc& CPPCompilerUtil::getCompiledWithDesc()
     }
 
     // If we are gcc, we can try clang and vice versa
-    if (desc.type == CPPCompiler::Type::GCC || desc.type == CPPCompiler::Type::Clang)
+    if (desc.type == CPPCompiler::CompilerType::GCC || desc.type == CPPCompiler::CompilerType::Clang)
     {
         CPPCompiler::Desc compatible = desc;
-        compatible.type = (compatible.type == CPPCompiler::Type::Clang) ? CPPCompiler::Type::GCC : CPPCompiler::Type::Clang;
+        compatible.type = (compatible.type == CPPCompiler::CompilerType::Clang) ? CPPCompiler::CompilerType::GCC : CPPCompiler::CompilerType::Clang;
 
         compiler = findCompiler(compilers, MatchType::MinGreaterEqual, compatible);
         if (compiler)
@@ -513,9 +306,9 @@ const CPPCompiler::Desc& CPPCompilerUtil::getCompiledWithDesc()
 static void _addGCCFamilyCompiler(const String& exeName, CPPCompilerSet* compilerSet)
 {
     CPPCompiler::Desc desc;
-    if (SLANG_SUCCEEDED(CPPCompilerUtil::calcGCCFamilyVersion(exeName, desc)))
+    if (SLANG_SUCCEEDED(GCCCompilerUtil::calcVersion(exeName, desc)))
     {
-        RefPtr<CPPCompiler> compiler(new GenericCPPCompiler(desc, exeName, &CPPCompilerUtil::calcGCCFamilyArgs));
+        RefPtr<CPPCompiler> compiler(new GenericCPPCompiler(desc, exeName, &GCCCompilerUtil::calcArgs, &GCCCompilerUtil::parseOutput));
         compilerSet->addCompiler(compiler);
     }
 }
diff --git a/source/core/slang-cpp-compiler.h b/source/core/slang-cpp-compiler.h
index 83c18bca2..60b534556 100644
--- a/source/core/slang-cpp-compiler.h
+++ b/source/core/slang-cpp-compiler.h
@@ -13,7 +13,7 @@ class CPPCompiler: public RefObject
 {
 public:
     typedef RefObject Super;
-    enum class Type
+    enum class CompilerType
     {
         Unknown,
         VisualStudio,
@@ -41,9 +41,9 @@ public:
         Int getVersionValue() const { return majorVersion * 100 + minorVersion;  }
 
             /// Ctor
-        Desc(Type inType = Type::Unknown, Int inMajorVersion = 0, Int inMinorVersion = 0):type(inType), majorVersion(inMajorVersion), minorVersion(inMinorVersion) {}
+        Desc(CompilerType inType = CompilerType::Unknown, Int inMajorVersion = 0, Int inMinorVersion = 0):type(inType), majorVersion(inMajorVersion), minorVersion(inMinorVersion) {}
 
-        Type type;                      ///< The type of the compiler
+        CompilerType type;                      ///< The type of the compiler
         Int majorVersion;               ///< Major version (interpretation is type specific)
         Int minorVersion;               ///< Minor version
     };
@@ -101,10 +101,68 @@ public:
         List<String> libraryPaths;
     };
 
+    struct OutputMessage
+    {
+        enum class Type
+        {
+            Unknown,
+            Info,
+            Warning,
+            Error,
+            CountOf,
+        };
+        enum class Stage
+        {
+            Compile,
+            Link,
+        };
+
+        void reset()
+        {
+            type = Type::Unknown;
+            stage = Stage::Compile;
+            fileLine = 0;
+        }
+        static UnownedStringSlice getTypeText(OutputMessage::Type type);
+
+
+        Type type;                      ///< The type of error
+        Stage stage;                    ///< The stage the error came from
+        String text;                    ///< The text of the error
+        String code;                    ///< The compiler specific error code
+        String filePath;                ///< The path the error originated from
+        Int fileLine;                   ///< The line number the error came from
+    };
+
+    struct Output
+    {
+            /// Reset to an initial empty state
+        void reset() { messages.clear(); result = SLANG_OK; }
+        
+            /// Get the number of messages by type
+        Index getCountByType(OutputMessage::Type type) const;
+            /// True if there are any messages of the type
+        bool has(OutputMessage::Type type) const { return getCountByType(type) > 0; }
+
+            /// Stores in outCounts, the amount of messages for the stage of each type
+        Int countByStage(OutputMessage::Stage stage, Index outCounts[Int(OutputMessage::Type::CountOf)]) const;
+
+            /// Append a summary to out
+        void appendSummary(StringBuilder& out) const;
+            /// Appends a summary that just identifies if there is an error of a type (not a count)
+        void appendSimplifiedSummary(StringBuilder& out) const;
+        
+            /// Remove all messages of the type
+        void removeByType(OutputMessage::Type type);
+
+        SlangResult result;
+        List<OutputMessage> messages;
+    };
+
         /// Get the desc of this compiler
     const Desc& getDesc() const { return m_desc;  }
         /// Compile using the specified options. The result is in resOut
-    virtual SlangResult compile(const CompileOptions& options, ExecuteResult& outResult) = 0;
+    virtual SlangResult compile(const CompileOptions& options, Output& outOutput) = 0;
 
 protected:
 
@@ -121,23 +179,27 @@ public:
     typedef CPPCompiler Super;
 
     typedef void(*CalcArgsFunc)(const CPPCompiler::CompileOptions& options, CommandLine& cmdLine);
+    typedef SlangResult(*ParseOutputFunc)(const ExecuteResult& exeResult, Output& output);
 
-    virtual SlangResult compile(const CompileOptions& options, ExecuteResult& outResult) SLANG_OVERRIDE;
+    virtual SlangResult compile(const CompileOptions& options, Output& outOutput) SLANG_OVERRIDE;
 
-    GenericCPPCompiler(const Desc& desc, const String& exeName, CalcArgsFunc func) :
+    GenericCPPCompiler(const Desc& desc, const String& exeName, CalcArgsFunc calcArgsFunc, ParseOutputFunc parseOutputFunc) :
         Super(desc),
-        m_func(func)
+        m_calcArgsFunc(calcArgsFunc),
+        m_parseOutputFunc(parseOutputFunc)
     {
         m_cmdLine.setExecutableFilename(exeName);
     }
 
-    GenericCPPCompiler(const Desc& desc, const CommandLine& cmdLine, CalcArgsFunc func) :
+    GenericCPPCompiler(const Desc& desc, const CommandLine& cmdLine, CalcArgsFunc calcArgsFunc, ParseOutputFunc parseOutputFunc) :
         Super(desc),
         m_cmdLine(cmdLine),
-        m_func(func)
+        m_calcArgsFunc(calcArgsFunc),
+        m_parseOutputFunc(parseOutputFunc)
     {}
 
-    CalcArgsFunc m_func;
+    CalcArgsFunc m_calcArgsFunc;
+    ParseOutputFunc m_parseOutputFunc;
     CommandLine m_cmdLine;
 };
 
@@ -188,18 +250,6 @@ struct CPPCompilerUtil
         Newest,
     };
 
-        /// Extracts version number into desc from text (assumes gcc/clang -v layout with a line with version)
-    static SlangResult parseGCCFamilyVersion(const UnownedStringSlice& text, const UnownedStringSlice& prefix, CPPCompiler::Desc& outDesc);
-
-        /// Runs the exeName, and extracts the version info into outDesc
-    static SlangResult calcGCCFamilyVersion(const String& exeName, CPPCompiler::Desc& outDesc);
-
-        /// Calculate gcc family compilers (including clang) cmdLine arguments from options
-    static void calcGCCFamilyArgs(const CompileOptions& options, CommandLine& cmdLine);
-
-        /// Calculate Visual Studio family compilers cmdLine arguments from options
-    static void calcVisualStudioArgs(const CompileOptions& options, CommandLine& cmdLine);
-
         /// Find a compiler
     static CPPCompiler* findCompiler(const CPPCompilerSet* set, MatchType matchType, const CPPCompiler::Desc& desc);
     static CPPCompiler* findCompiler(const List<CPPCompiler*>& compilers, MatchType matchType, const CPPCompiler::Desc& desc);
diff --git a/source/core/slang-gcc-compiler-util.cpp b/source/core/slang-gcc-compiler-util.cpp
new file mode 100644
index 000000000..9f22526a1
--- /dev/null
+++ b/source/core/slang-gcc-compiler-util.cpp
@@ -0,0 +1,460 @@
+// slang-gcc-compiler-util.cpp
+#include "slang-gcc-compiler-util.h"
+
+#include "slang-common.h"
+#include "../../slang-com-helper.h"
+#include "slang-string-util.h"
+
+#include "slang-io.h"
+#include "slang-shared-library.h"
+
+namespace Slang
+{
+
+/* static */SlangResult GCCCompilerUtil::parseVersion(const UnownedStringSlice& text, const UnownedStringSlice& prefix, CPPCompiler::Desc& outDesc)
+{
+    List<UnownedStringSlice> lines;
+    StringUtil::calcLines(text, lines);
+
+    for (auto line : lines)
+    {
+        if (line.startsWith(prefix))
+        {
+            const UnownedStringSlice remainingSlice = UnownedStringSlice(line.begin() + prefix.size(), line.end()).trim();
+            const Index versionEndIndex = remainingSlice.indexOf(' ');
+            if (versionEndIndex < 0)
+            {
+                return SLANG_FAIL;
+            }
+
+            const UnownedStringSlice versionSlice(remainingSlice.begin(), remainingSlice.begin() + versionEndIndex);
+
+            // Version is in format 0.0.0 
+            List<UnownedStringSlice> split;
+            StringUtil::split(versionSlice, '.', split);
+            List<Int> digits;
+
+            for (auto v : split)
+            {
+                Int version;
+                SLANG_RETURN_ON_FAIL(StringUtil::parseInt(v, version));
+                digits.add(version);
+            }
+
+            if (digits.getCount() < 2)
+            {
+                return SLANG_FAIL;
+            }
+
+            outDesc.majorVersion = digits[0];
+            outDesc.minorVersion = digits[1];
+            return SLANG_OK;
+        }
+    }
+
+    return SLANG_FAIL;
+}
+
+SlangResult GCCCompilerUtil::calcVersion(const String& exeName, CPPCompiler::Desc& outDesc)
+{
+    CommandLine cmdLine;
+    cmdLine.setExecutableFilename(exeName);
+    cmdLine.addArg("-v");
+
+    ExecuteResult exeRes;
+    SLANG_RETURN_ON_FAIL(ProcessUtil::execute(cmdLine, exeRes));
+
+    const UnownedStringSlice prefixes[] =
+    {
+        UnownedStringSlice::fromLiteral("clang version"),
+        UnownedStringSlice::fromLiteral("gcc version"),
+        UnownedStringSlice::fromLiteral("Apple LLVM version"),
+    };
+    const CPPCompiler::CompilerType types[] =
+    {
+        CPPCompiler::CompilerType::Clang,
+        CPPCompiler::CompilerType::GCC,
+        CPPCompiler::CompilerType::Clang,
+    };
+
+    SLANG_COMPILE_TIME_ASSERT(SLANG_COUNT_OF(prefixes) == SLANG_COUNT_OF(types));
+
+    for (Index i = 0; i < SLANG_COUNT_OF(prefixes); ++i)
+    {
+        // Set the type
+        outDesc.type = types[i];
+        // Extract the version
+        if (SLANG_SUCCEEDED(parseVersion(exeRes.standardError.getUnownedSlice(), prefixes[i], outDesc)))
+        {
+            return SLANG_OK;
+        }
+    }
+    return SLANG_FAIL;
+}
+
+static SlangResult _parseErrorType(const UnownedStringSlice& in, CPPCompiler::OutputMessage::Type& outType)
+{
+    typedef CPPCompiler::OutputMessage::Type Type;
+
+    if (in == "error" || in == "fatal error")
+    {
+        outType = Type::Error;
+    }
+    else if (in == "warning")
+    {
+        outType = Type::Warning;
+    }
+    else if (in == "info" || in == "note")
+    {
+        outType = Type::Info;
+    }
+    else
+    {
+        return SLANG_FAIL;
+    }
+    return SLANG_OK;
+}
+
+namespace { // anonymous
+
+enum class LineParseResult
+{
+    Single,             ///< It's a single line
+    Start,              ///< Line was the start of a message
+    Continuation,       ///< Not totally clear, add to previous line if nothing else hit
+    Ignore,             ///< Ignore the line
+};
+    
+} // anonymous
+    
+static SlangResult _parseGCCFamilyLine(const UnownedStringSlice& line, LineParseResult& outLineParseResult, CPPCompiler::OutputMessage& outMsg)
+{
+    typedef CPPCompiler::OutputMessage OutputMessage;
+    typedef OutputMessage::Type Type;
+    
+    // Set to default case
+    outLineParseResult = LineParseResult::Ignore;
+    
+    /* example error output from different scenarios */
+    
+    /*
+        tests/cpp-compiler/c-compile-error.c: In function ‘int main(int, char**)’:
+        tests/cpp-compiler/c-compile-error.c:8:13: error: ‘b’ was not declared in this scope
+        int a = b + c;
+        ^
+        tests/cpp-compiler/c-compile-error.c:8:17: error: ‘c’ was not declared in this scope
+        int a = b + c;
+        ^
+    */
+
+    /* /tmp/ccS0JCWe.o:c-compile-link-error.c:(.rdata$.refptr.thing[.refptr.thing]+0x0): undefined reference to `thing'
+       collect2: error: ld returned 1 exit status*/
+
+    /*
+     clang: warning: treating 'c' input as 'c++' when in C++ mode, this behavior is deprecated [-Wdeprecated]
+     Undefined symbols for architecture x86_64:
+     "_thing", referenced from:
+     _main in c-compile-link-error-a83ace.o
+     ld: symbol(s) not found for architecture x86_64
+     clang: error: linker command failed with exit code 1 (use -v to see invocation) */
+
+     /* /tmp/c-compile-link-error-ccf151.o: In function `main':
+      c-compile-link-error.c:(.text+0x19): undefined reference to `thing'
+     clang: error: linker command failed with exit code 1 (use -v to see invocation)
+     */
+
+     /* /tmp/c-compile-link-error-301c8c.o: In function `main':
+        /home/travis/build/shader-slang/slang/tests/cpp-compiler/c-compile-link-error.c:10: undefined reference to `thing'
+        clang-7: error: linker command failed with exit code 1 (use -v to see invocation)*/
+
+    outMsg.stage = OutputMessage::Stage::Compile;
+
+    List<UnownedStringSlice> split;
+    StringUtil::split(line, ':', split);
+
+    if (split.getCount() == 2)
+    {
+        const auto split0 = split[0].trim();
+        if (split0 == UnownedStringSlice::fromLiteral("ld"))
+        {
+            // We'll ignore for now
+            outMsg.stage = OutputMessage::Stage::Link;
+            outMsg.type = Type::Info;
+            outMsg.text = split[1].trim();
+            outLineParseResult = LineParseResult::Start;
+            return SLANG_OK;
+        }
+        outLineParseResult = LineParseResult::Ignore;
+        return SLANG_OK;
+    }
+    else if (split.getCount() == 3)
+    {
+        const auto split0 = split[0].trim();
+        const auto split1 = split[1].trim();
+        const auto text = split[2].trim();
+
+        // Check for special handling for clang
+        if (split0.startsWith(UnownedStringSlice::fromLiteral("clang")))
+        {
+            // Extract the type
+            SLANG_RETURN_ON_FAIL(_parseErrorType(split[1].trim(), outMsg.type));
+
+            if (text.startsWith("linker command failed"))
+            {
+                outMsg.stage = OutputMessage::Stage::Link;
+            }
+
+            outMsg.text = text;
+            outLineParseResult = LineParseResult::Start;
+            return SLANG_OK;
+        }
+        else if (split1.startsWith("(.text"))
+        {
+            // This is a little weak... but looks like it's a link error
+            outMsg.filePath = split[0];
+            outMsg.type = Type::Error;
+            outMsg.stage = OutputMessage::Stage::Link;
+            outMsg.text = text;
+            outLineParseResult = LineParseResult::Single;
+            return SLANG_OK;
+        }
+        else if (text.startsWith("ld returned"))
+        {
+            outMsg.stage = CPPCompiler::OutputMessage::Stage::Link;
+            SLANG_RETURN_ON_FAIL(_parseErrorType(split[1].trim(), outMsg.type));
+            outMsg.text = line;
+            outLineParseResult = LineParseResult::Single;
+            return SLANG_OK;
+        }
+        else if (text == "")
+        {
+            // This is probably a prelude line, we'll just ignore it
+            outLineParseResult = LineParseResult::Ignore;
+            return SLANG_OK;
+        }
+    }
+    else if (split.getCount() == 4)
+    {
+        // Probably a link error, give the source line
+        String ext = Path::getFileExt(split[0]);
+
+        // Maybe a bit fragile -> but probably okay for now
+        if (ext != "o" && ext != "obj")
+        {
+            outLineParseResult = LineParseResult::Ignore;
+            return SLANG_OK;
+        }
+        else
+        {
+            outMsg.filePath = split[1];
+            outMsg.fileLine = 0;
+            outMsg.type = OutputMessage::Type::Error;
+            outMsg.stage = OutputMessage::Stage::Link;
+            outMsg.text = split[3];
+            
+            outLineParseResult = LineParseResult::Start;
+            return SLANG_OK;
+        }
+    }
+    else if (split.getCount() == 5)
+    {
+        // Probably a regular error line
+        SLANG_RETURN_ON_FAIL(_parseErrorType(split[3].trim(), outMsg.type));
+
+        outMsg.filePath = split[0];
+        SLANG_RETURN_ON_FAIL(StringUtil::parseInt(split[1], outMsg.fileLine));
+        outMsg.text = split[4];
+
+        outLineParseResult = LineParseResult::Start;
+        return SLANG_OK;
+    }
+    
+    // Assume it's a continuation
+    outLineParseResult = LineParseResult::Continuation;
+    return SLANG_OK;
+}
+
+/* static */SlangResult GCCCompilerUtil::parseOutput(const ExecuteResult& exeRes, CPPCompiler::Output& outOutput)
+{
+    LineParseResult prevLineResult = LineParseResult::Ignore;
+    
+    outOutput.reset();
+
+    for (auto line : LineParser(exeRes.standardError.getUnownedSlice()))
+    {
+        CPPCompiler::OutputMessage msg;
+        LineParseResult lineRes;
+        
+        SLANG_RETURN_ON_FAIL(_parseGCCFamilyLine(line, lineRes, msg));
+        
+        switch (lineRes)
+        {
+            case LineParseResult::Start:
+            {
+                // It's start of a new message
+                outOutput.messages.add(msg);
+                prevLineResult = LineParseResult::Start;
+                break;
+            }
+            case LineParseResult::Single:
+            {
+                // It's a single message, without anything following
+                outOutput.messages.add(msg);
+                prevLineResult = LineParseResult::Ignore;
+                break;
+            }
+            case LineParseResult::Continuation:
+            {
+                if (prevLineResult == LineParseResult::Start || prevLineResult == LineParseResult::Continuation)
+                {
+                    if (outOutput.messages.getCount() > 0)
+                    {
+                        // We are now in a continuation, add to the last
+                        auto& text = outOutput.messages.getLast().text;
+                        text.append("\n");
+                        text.append(line);
+                    }
+                    prevLineResult = LineParseResult::Continuation;
+                }
+                break;
+            }
+            case LineParseResult::Ignore:
+            {
+                prevLineResult = lineRes;
+                break;
+            }
+            default: return SLANG_FAIL;
+        }
+    }
+
+    if (outOutput.has(CPPCompiler::OutputMessage::Type::Error) || exeRes.resultCode != 0)
+    {
+        outOutput.result = SLANG_FAIL;
+    }
+
+    return SLANG_OK;
+}
+
+/* static */void GCCCompilerUtil::calcArgs(const CompileOptions& options, CommandLine& cmdLine)
+{
+    cmdLine.addArg("-fvisibility=hidden");
+    // Use shared libraries
+    //cmdLine.addArg("-shared");
+
+    switch (options.optimizationLevel)
+    {
+        case OptimizationLevel::Debug:
+        {
+            // No optimization
+            cmdLine.addArg("-O0");
+            break;
+        }
+        case OptimizationLevel::Normal:
+        {
+            cmdLine.addArg("-Os");
+            break;
+        }
+        default: break;
+    }
+
+    if (options.debugInfoType != DebugInfoType::None)
+    {
+        cmdLine.addArg("-g");
+    }
+
+    switch (options.targetType)
+    {
+        case TargetType::SharedLibrary:
+        {
+            // Shared library
+            cmdLine.addArg("-shared");
+            // Position independent
+            cmdLine.addArg("-fPIC");
+
+            String sharedLibraryPath = SharedLibrary::calcPlatformPath(options.modulePath.getUnownedSlice());
+
+            cmdLine.addArg("-o");
+            cmdLine.addArg(sharedLibraryPath);
+            break;
+        }
+        case TargetType::Executable:
+        {
+            cmdLine.addArg("-o");
+
+            StringBuilder builder;
+            builder << options.modulePath;
+            builder << ProcessUtil::getExecutableSuffix();
+
+            cmdLine.addArg(options.modulePath);
+            break;
+        }
+        case TargetType::Object:
+        {
+            // Don't link, just produce object file
+            cmdLine.addArg("-c");
+            break;
+        }
+        default: break;
+    }
+
+    // Add defines
+    for (const auto& define : options.defines)
+    {
+        StringBuilder builder;
+        builder << define.nameWithSig;
+        if (define.value.getLength())
+        {
+            builder << "=" << define.value;
+        }
+
+        cmdLine.addArg(builder);
+    }
+
+    // Add includes
+    for (const auto& include : options.includePaths)
+    {
+        cmdLine.addArg("-I");
+        cmdLine.addArg(include);
+    }
+
+    // Link options
+    if (0) // && options.targetType != TargetType::Object)
+    {
+        //linkOptions << "-Wl,";
+        //cmdLine.addArg(linkOptions);
+    }
+
+    if (options.targetType == TargetType::SharedLibrary)
+    {
+#if !SLANG_APPLE_FAMILY
+        // On MacOS, this linker option is not supported. That's ok though in
+        // so far as on MacOS it does report any unfound symbols without the option.
+
+        // Linker flag to report any undefined symbols as a link error
+        cmdLine.addArg("-Wl,--no-undefined");
+#endif
+    }
+
+    // Files to compile
+    for (const auto& sourceFile : options.sourceFiles)
+    {
+        cmdLine.addArg(sourceFile);
+    }
+
+    for (const auto& libPath : options.libraryPaths)
+    {
+        // Note that any escaping of the path is handled in the ProcessUtil::
+        cmdLine.addArg("-L");
+        cmdLine.addArg(libPath);
+        cmdLine.addArg("-F");
+        cmdLine.addArg(libPath);
+    }
+
+    if (options.sourceType == SourceType::CPP)
+    {
+        // Make STD libs available
+        cmdLine.addArg("-lstdc++");
+    }
+}
+
+}
diff --git a/source/core/slang-gcc-compiler-util.h b/source/core/slang-gcc-compiler-util.h
new file mode 100644
index 000000000..29070fc61
--- /dev/null
+++ b/source/core/slang-gcc-compiler-util.h
@@ -0,0 +1,33 @@
+#ifndef SLANG_GCC_COMPILER_UTIL_H
+#define SLANG_GCC_COMPILER_UTIL_H
+
+#include "slang-cpp-compiler.h"
+
+namespace Slang
+{
+
+/* Utility for processing input and output of gcc-like compilers, including clang */
+struct GCCCompilerUtil
+{
+    typedef CPPCompiler::CompileOptions CompileOptions;
+    typedef CPPCompiler::OptimizationLevel OptimizationLevel;
+    typedef CPPCompiler::TargetType TargetType;
+    typedef CPPCompiler::DebugInfoType DebugInfoType;
+    typedef CPPCompiler::SourceType SourceType;
+
+        /// Extracts version number into desc from text (assumes gcc/clang -v layout with a line with version)
+    static SlangResult parseVersion(const UnownedStringSlice& text, const UnownedStringSlice& prefix, CPPCompiler::Desc& outDesc);
+
+        /// Runs the exeName, and extracts the version info into outDesc
+    static SlangResult calcVersion(const String& exeName, CPPCompiler::Desc& outDesc);
+
+        /// Calculate gcc family compilers (including clang) cmdLine arguments from options
+    static void calcArgs(const CompileOptions& options, CommandLine& cmdLine);
+
+        /// Parse ExecuteResult into Output
+    static SlangResult parseOutput(const ExecuteResult& exeRes, CPPCompiler::Output& outOutput);
+};
+
+}
+
+#endif
diff --git a/source/core/slang-string-util.cpp b/source/core/slang-string-util.cpp
index 95caf8319..4295a2c52 100644
--- a/source/core/slang-string-util.cpp
+++ b/source/core/slang-string-util.cpp
@@ -39,6 +39,45 @@ static const Guid IID_ISlangBlob = SLANG_UUID_ISlangBlob;
     }
 }
 
+/* static */void StringUtil::join(const List<String>& values, char separator, StringBuilder& out)
+{
+    join(values, UnownedStringSlice(&separator, 1), out);
+}
+
+/* static */void StringUtil::join(const List<String>& values, const UnownedStringSlice& separator, StringBuilder& out)
+{
+    const Index count = values.getCount();
+    if (count <= 0)
+    {
+        return;
+    }
+    out.append(values[0]);
+    for (Index i = 1; i < count; i++)
+    {
+        out.append(separator);
+        out.append(values[i]);
+    }
+}
+
+/* static */void StringUtil::join(const UnownedStringSlice* values, Index valueCount, char separator, StringBuilder& out)
+{
+    join(values, valueCount, UnownedStringSlice(&separator, 1), out);
+}
+
+/* static */void StringUtil::join(const UnownedStringSlice* values, Index valueCount, const UnownedStringSlice& separator, StringBuilder& out)
+{
+    if (valueCount <= 0)
+    {
+        return;
+    }
+    out.append(values[0]);
+    for (Index i = 1; i < valueCount; i++)
+    {
+        out.append(separator);
+        out.append(values[i]);
+    }
+}
+
 /* static */int StringUtil::indexOfInSplit(const UnownedStringSlice& in, char splitChar, const UnownedStringSlice& find)
 {
     const char* start = in.begin();
@@ -285,4 +324,45 @@ ComPtr<ISlangBlob> StringUtil::createStringBlob(const String& string)
     }
 }
 
+SLANG_FORCE_INLINE static bool _isDigit(char c)
+{
+    return (c >= '0' && c <= '9');
+}
+
+/* static */SlangResult StringUtil::parseInt(const UnownedStringSlice& in, Int& outValue)
+{
+    const char* cur = in.begin();
+    const char* end = in.end();
+
+    bool negate = false;
+    if (cur < end && *cur == '-')
+    {
+        negate = true;
+        cur++;
+    }
+
+    // We need at least one digit
+    if (cur >= end || !_isDigit(*cur))
+    {
+        return SLANG_FAIL;
+    }
+    
+    Int value = *cur++ - '0';
+    // Do the remaining digits
+    for (; cur < end; ++cur)
+    {
+        const char c = *cur;
+        if (!_isDigit(c))
+        {
+            return SLANG_FAIL;
+        }
+        value = value * 10 + (c - '0');
+    }
+
+    value = negate ? -value : value;
+
+    outValue = value;
+    return SLANG_OK;
+}
+
 } // namespace Slang
diff --git a/source/core/slang-string-util.h b/source/core/slang-string-util.h
index 74ec75dc6..77b7ca2a3 100644
--- a/source/core/slang-string-util.h
+++ b/source/core/slang-string-util.h
@@ -41,6 +41,13 @@ struct StringUtil
         /// Slices contents will directly address into in, so contents will only stay valid as long as in does.
     static void split(const UnownedStringSlice& in, char splitChar, List<UnownedStringSlice>& slicesOut);
 
+        /// Append the joining of in items, separated by 'separator' onto out
+    static void join(const List<String>& in, char separator, StringBuilder& out);
+    static void join(const List<String>& in, const UnownedStringSlice& separator, StringBuilder& out);
+
+    static void join(const UnownedStringSlice* values, Index valueCount, char separator, StringBuilder& out);
+    static void join(const UnownedStringSlice* values, Index valueCount, const UnownedStringSlice& separator, StringBuilder& out);
+
         /// Equivalent to doing a split and then finding the index of 'find' on the array
         /// Returns -1 if not found
     static int indexOfInSplit(const UnownedStringSlice& in, char splitChar, const UnownedStringSlice& find);
@@ -94,6 +101,9 @@ struct StringUtil
 
         /// Equal if the lines are equal (in effect a way to ignore differences in line breaks)
     static bool areLinesEqual(const UnownedStringSlice& a, const UnownedStringSlice& b);
+
+        /// Convert in to int. Returns SLANG_FAIL on error
+    static SlangResult parseInt(const UnownedStringSlice& in, Int& outValue);
 };
 
 /* A helper class that allows parsing of lines from text with iteration. Uses StringUtil::extractLine for the actual underlying implementation. */
diff --git a/source/core/slang-string.cpp b/source/core/slang-string.cpp
index 54703def1..8b2a35b3f 100644
--- a/source/core/slang-string.cpp
+++ b/source/core/slang-string.cpp
@@ -7,9 +7,15 @@ namespace Slang
 
     SLANG_RETURN_NEVER void signalUnexpectedError(char const* message)
     {
+        // Can be useful to uncomment during debug when problem is on CI
+        // printf("Unexpected: %s\n", message);
         throw InternalError(message);
     }
 
+    SLANG_FORCE_INLINE static bool _isWhiteSpace(char c)
+    {
+        return c == ' ' || c == '\t';
+    }
 
     // OSString
 
@@ -100,6 +106,17 @@ namespace Slang
         return endsWith(UnownedTerminatedStringSlice(str));
     }
 
+    
+    UnownedStringSlice UnownedStringSlice::trim() const
+    {
+        const char* start = m_begin;
+        const char* end = m_end;
+
+        while (start < end && _isWhiteSpace(*start)) start++;
+        while (end > start && _isWhiteSpace(end[-1])) end--;
+        return UnownedStringSlice(start, end);
+    }
+
 
     // StringSlice
 
diff --git a/source/core/slang-string.h b/source/core/slang-string.h
index 560d137db..cb2731cee 100644
--- a/source/core/slang-string.h
+++ b/source/core/slang-string.h
@@ -98,10 +98,22 @@ namespace Slang
             return Index(m_end - m_begin);
         }
 
-        int indexOf(char c) const
+        Index indexOf(char c) const
         {
-            const int size = int(m_end - m_begin);
-            for (int i = 0; i < size; ++i)
+            const Index size = int(m_end - m_begin);
+            for (Index i = 0; i < size; ++i)
+            {
+                if (m_begin[i] == c)
+                {
+                    return i;
+                }
+            }
+            return -1;
+        }
+        Index lastIndexOf(char c) const
+        {
+            const Index size = Index(m_end - m_begin);
+            for (Index i = size - 1; i >= 0; --i)
             {
                 if (m_begin[i] == c)
                 {
@@ -156,6 +168,9 @@ namespace Slang
         bool endsWith(UnownedStringSlice const& other) const;
         bool endsWith(char const* str) const;
 
+
+        UnownedStringSlice trim() const;
+
         int GetHashCode() const
         {
             return Slang::GetHashCode(m_begin, size_t(m_end - m_begin)); 
diff --git a/source/core/slang-visual-studio-compiler-util.cpp b/source/core/slang-visual-studio-compiler-util.cpp
new file mode 100644
index 000000000..20d655e78
--- /dev/null
+++ b/source/core/slang-visual-studio-compiler-util.cpp
@@ -0,0 +1,300 @@
+// slang-visual-studio-compiler-util.cpp
+#include "slang-visual-studio-compiler-util.h"
+
+#include "slang-common.h"
+#include "../../slang-com-helper.h"
+#include "slang-string-util.h"
+
+#include "slang-io.h"
+
+namespace Slang
+{
+
+/* static */void VisualStudioCompilerUtil::calcArgs(const CompileOptions& options, CommandLine& cmdLine)
+{
+    // https://docs.microsoft.com/en-us/cpp/build/reference/compiler-options-listed-alphabetically?view=vs-2019
+
+    cmdLine.addArg("/nologo");
+    // Generate complete debugging information
+    cmdLine.addArg("/Zi");
+    // Display full path of source files in diagnostics
+    cmdLine.addArg("/FC");
+
+    if (options.flags & CompileOptions::Flag::EnableExceptionHandling)
+    {
+        if (options.sourceType == SourceType::CPP)
+        {
+            // https://docs.microsoft.com/en-us/cpp/build/reference/eh-exception-handling-model?view=vs-2019
+            // Assumes c functions cannot throw
+            cmdLine.addArg("/EHsc");
+        }
+    }
+
+    switch (options.optimizationLevel)
+    {
+        case OptimizationLevel::Debug:
+        {
+            // No optimization
+            cmdLine.addArg("/Od");
+
+            cmdLine.addArg("/MDd");
+            break;
+        }
+        case OptimizationLevel::Normal:
+        {
+            cmdLine.addArg("/O2");
+            // Multithreaded DLL
+            cmdLine.addArg("/MD");
+            break;
+        }
+        default: break;
+    }
+
+    // /Fd - followed by name of the pdb file
+    if (options.debugInfoType != DebugInfoType::None)
+    {
+        cmdLine.addPrefixPathArg("/Fd", options.modulePath, ".pdb");
+    }
+
+    switch (options.targetType)
+    {
+        case TargetType::SharedLibrary:
+        {
+            // Create dynamic link library
+            if (options.optimizationLevel == OptimizationLevel::Debug)
+            {
+                cmdLine.addArg("/LDd");
+            }
+            else
+            {
+                cmdLine.addArg("/LD");
+            }
+
+            cmdLine.addPrefixPathArg("/Fe", options.modulePath, ".dll");
+            break;
+        }
+        case TargetType::Executable:
+        {
+            cmdLine.addPrefixPathArg("/Fe", options.modulePath, ".exe");
+            break;
+        }
+        default: break;
+    }
+
+    // Object file specify it's location - needed if we are out
+    cmdLine.addPrefixPathArg("/Fo", options.modulePath, ".obj");
+
+    // Add defines
+    for (const auto& define : options.defines)
+    {
+        StringBuilder builder;
+        builder << define.nameWithSig;
+        if (define.value.getLength())
+        {
+            builder << "=" << define.value;
+        }
+
+        cmdLine.addArg(builder);
+    }
+
+    // Add includes
+    for (const auto& include : options.includePaths)
+    {
+        cmdLine.addArg("/I");
+        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)
+
+    // Files to compile
+    for (const auto& sourceFile : options.sourceFiles)
+    {
+        cmdLine.addArg(sourceFile);
+    }
+
+    // Link options (parameters past /link go to linker)
+    cmdLine.addArg("/link");
+
+    for (const auto& libPath : options.libraryPaths)
+    {
+        // Note that any escaping of the path is handled in the ProcessUtil::
+        cmdLine.addPrefixPathArg("/LIBPATH:", libPath);
+    }
+}
+
+static SlangResult _parseErrorType(const UnownedStringSlice& in, CPPCompiler::OutputMessage::Type& outType)
+{
+    typedef CPPCompiler::OutputMessage::Type Type;
+
+    if (in == "error" || in == "fatal error")
+    {
+        outType = Type::Error;
+    }
+    else if (in == "warning")
+    {
+        outType = Type::Warning;
+    }
+    else if (in == "info")
+    {
+        outType = Type::Info;
+    }
+    else
+    {
+        return SLANG_FAIL;
+    }
+    return SLANG_OK;
+}
+
+static SlangResult _parseVisualStudioLine(const UnownedStringSlice& line, CPPCompiler::OutputMessage& outMsg)
+{
+    typedef CPPCompiler::OutputMessage OutputMessage;
+
+    UnownedStringSlice linkPrefix = UnownedStringSlice::fromLiteral("LINK :");
+    if (line.startsWith(linkPrefix))
+    {
+        outMsg.stage = OutputMessage::Stage::Link;
+        outMsg.type = OutputMessage::Type::Info;
+
+        outMsg.text = UnownedStringSlice(line.begin() + linkPrefix.size(), line.end());
+
+        return SLANG_OK;
+    }
+
+    outMsg.stage = OutputMessage::Stage::Compile;
+
+    const char*const start = line.begin();
+    const char*const end = line.end();
+
+    UnownedStringSlice postPath;
+    // Handle the path and line no
+    {
+        const char* cur = start;
+
+        // We have to assume it is a path up to the first : that isn't part of a drive specification
+
+        if ((end - cur > 2) && Path::isDriveSpecification(UnownedStringSlice(start, start + 2)))
+        {
+            // Skip drive spec
+            cur += 2;
+        }
+
+        // Find the first colon after this
+        Index colonIndex = UnownedStringSlice(cur, end).indexOf(':');
+        if (colonIndex < 0)
+        {
+            return SLANG_FAIL;
+        }
+
+        // Looks like we have a line number
+        if (cur[colonIndex - 1] == ')')
+        {
+            const char* lineNoEnd = cur + colonIndex - 1;
+            const char* lineNoStart = lineNoEnd;
+            while (lineNoStart > start && *lineNoStart != '(')
+            {
+                lineNoStart--;
+            }
+            // Check this appears plausible
+            if (*lineNoStart != '(' || *lineNoEnd != ')')
+            {
+                return SLANG_FAIL;
+            }
+            Int numDigits = 0;
+            Int lineNo = 0;
+            for (const char* digitCur = lineNoStart + 1; digitCur < lineNoEnd; ++digitCur)
+            {
+                char c = *digitCur;
+                if (c >= '0' && c <= '9')
+                {
+                    lineNo = lineNo * 10 + (c - '0');
+                    numDigits++;
+                }
+                else
+                {
+                    return SLANG_FAIL;
+                }
+            }
+            if (numDigits == 0)
+            {
+                return SLANG_FAIL;
+            }
+
+            outMsg.filePath = UnownedStringSlice(start, lineNoStart);
+            outMsg.fileLine = lineNo;
+        }
+        else
+        {
+            outMsg.filePath = UnownedStringSlice(start, cur + colonIndex);
+            outMsg.fileLine = 0;
+        }
+
+        // Save the remaining text in 'postPath'
+        postPath = UnownedStringSlice(cur + colonIndex + 1, end);
+    }
+
+    // Split up the error section
+    UnownedStringSlice postError;
+    {
+        // tests/cpp-compiler/c-compile-link-error.exe : fatal error LNK1120: 1 unresolved externals
+
+        const Index errorColonIndex = postPath.indexOf(':');
+        if (errorColonIndex < 0)
+        {
+            return SLANG_FAIL;
+        }
+
+        const UnownedStringSlice errorSection = UnownedStringSlice(postPath.begin(), postPath.begin() + errorColonIndex);
+        Index errorCodeIndex = errorSection.lastIndexOf(' ');
+        if (errorCodeIndex < 0)
+        {
+            return SLANG_FAIL;
+        }
+
+        // Extract the code
+        outMsg.code = UnownedStringSlice(errorSection.begin() + errorCodeIndex + 1, errorSection.end());
+        if (outMsg.code.startsWith(UnownedStringSlice::fromLiteral("LNK")))
+        {
+            outMsg.stage = OutputMessage::Stage::Link;
+        }
+
+        // Extract the bit before the code
+        SLANG_RETURN_ON_FAIL(_parseErrorType(UnownedStringSlice(errorSection.begin(), errorSection.begin() + errorCodeIndex).trim(), outMsg.type));
+
+        // Link codes start with LNK prefix
+        postError = UnownedStringSlice(postPath.begin() + errorColonIndex + 1, end); 
+    }
+
+    outMsg.text = postError;
+
+    return SLANG_OK;
+}
+
+/* static */SlangResult VisualStudioCompilerUtil::parseOutput(const ExecuteResult& exeRes, CPPCompiler::Output& outOutput)
+{
+    outOutput.reset();
+
+    for (auto line : LineParser(exeRes.standardOutput.getUnownedSlice()))
+    {
+#if 0
+        fwrite(line.begin(), 1, line.size(), stdout);
+        fprintf(stdout, "\n");
+#endif
+
+        OutputMessage msg;
+        if (SLANG_SUCCEEDED(_parseVisualStudioLine(line, msg)))
+        {
+            outOutput.messages.add(msg);
+        }
+    }
+
+    // if it has a compilation error.. set on output
+    if (outOutput.has(OutputMessage::Type::Error))
+    {
+        outOutput.result = SLANG_FAIL;
+    }
+
+    return SLANG_OK;
+}
+
+}
diff --git a/source/core/slang-visual-studio-compiler-util.h b/source/core/slang-visual-studio-compiler-util.h
new file mode 100644
index 000000000..86845b5af
--- /dev/null
+++ b/source/core/slang-visual-studio-compiler-util.h
@@ -0,0 +1,26 @@
+#ifndef SLANG_VISUAL_STUDIO_COMPILER_UTIL_H
+#define SLANG_VISUAL_STUDIO_COMPILER_UTIL_H
+
+#include "slang-cpp-compiler.h"
+
+namespace Slang
+{
+
+struct VisualStudioCompilerUtil
+{
+    typedef CPPCompiler::CompileOptions CompileOptions;
+    typedef CPPCompiler::OptimizationLevel OptimizationLevel;
+    typedef CPPCompiler::TargetType TargetType;
+    typedef CPPCompiler::DebugInfoType DebugInfoType;
+    typedef CPPCompiler::SourceType SourceType;
+    typedef CPPCompiler::OutputMessage OutputMessage;
+
+        /// Calculate Visual Studio family compilers cmdLine arguments from options
+    static void calcArgs(const CompileOptions& options, CommandLine& cmdLine);
+        /// Parse Visual Studio exeRes into CPPCompiler::Output
+    static SlangResult parseOutput(const ExecuteResult& exeRes, CPPCompiler::Output& outOutput);
+};
+
+}
+
+#endif
diff --git a/source/core/windows/slang-win-visual-studio-util.cpp b/source/core/windows/slang-win-visual-studio-util.cpp
index 81d77c710..7e683ee55 100644
--- a/source/core/windows/slang-win-visual-studio-util.cpp
+++ b/source/core/windows/slang-win-visual-studio-util.cpp
@@ -4,6 +4,8 @@
 #include "../slang-process-util.h"
 #include "../slang-string-util.h"
 
+#include "../slang-visual-studio-compiler-util.h"
+
 #ifdef _WIN32
 #   define WIN32_LEAN_AND_MEAN
 #   define NOMINMAX
@@ -291,7 +293,7 @@ static SlangResult _find(int versionIndex, WinVisualStudioUtil::VersionPath& out
             CommandLine cmdLine;
             calcExecuteCompilerArgs(versionPath, cmdLine);
             
-            RefPtr<GenericCPPCompiler> compiler = new GenericCPPCompiler(desc, cmdLine, &CPPCompilerUtil::calcVisualStudioArgs);
+            RefPtr<GenericCPPCompiler> compiler = new GenericCPPCompiler(desc, cmdLine, &VisualStudioCompilerUtil::calcArgs, &VisualStudioCompilerUtil::parseOutput);
             set->addCompiler(compiler);
         }
     }
diff --git a/source/core/windows/slang-win-visual-studio-util.h b/source/core/windows/slang-win-visual-studio-util.h
index 76e1cc710..34be8473d 100644
--- a/source/core/windows/slang-win-visual-studio-util.h
+++ b/source/core/windows/slang-win-visual-studio-util.h
@@ -51,14 +51,11 @@ struct WinVisualStudioUtil
         /// Convert a version number into a string
     static void append(Version version, StringBuilder& outBuilder);
 
-        /// Calculate the command line args
-    static void calcArgs(const CPPCompiler::CompileOptions& options, CommandLine& cmdLine);
-
         /// Get version as desc
     static CPPCompiler::Desc getDesc(Version version)
     {
         CPPCompiler::Desc desc;
-        desc.type = CPPCompiler::Type::VisualStudio;
+        desc.type = CPPCompiler::CompilerType::VisualStudio;
         desc.majorVersion = Int(version) / 10;
         desc.minorVersion = Int(version) % 10;
         return desc;