Rewriter: improvements plus extract uniforms to global scope (#2730)

- Added rewriter functions for extracting uniforms into global scope
- Will not work if name collides (namespaces have bugs)
- Values under cbuffer _Params, resources outside (more bugs)
- Added rewriter HLSLOptions and support all through RewriteWithOptions
- Refactored dxr.exe to use HLSLOptions and RewriteWithOptions
- Exposed Write*VersionInfo functions from dxclib
- Fixed issue with External[Lib/Fn] for version printing.

Author: tex3d

include/dxc/Support/HLSLOptions.h

@@ -41,6 +41,7 @@ enum HlslFlags {
   NoArgumentUnused = (1 << 14),
   CoreOption = (1 << 15),
   ISenseOption = (1 << 16),
+  RewriteOption = (1 << 17),
 };
 
 enum ID {
@@ -64,7 +65,7 @@ static const unsigned CompilerFlags = HlslFlags::CoreOption;
 /// Flags for dxc.exe command-line tool.
 static const unsigned DxcFlags = HlslFlags::CoreOption | HlslFlags::DriverOption;
 /// Flags for dxr.exe command-line tool.
-static const unsigned DxrFlags = HlslFlags::CoreOption | HlslFlags::DriverOption;
+static const unsigned DxrFlags = HlslFlags::RewriteOption | HlslFlags::DriverOption;
 /// Flags for IDxcIntelliSense APIs.
 static const unsigned ISenseFlags = HlslFlags::CoreOption | HlslFlags::ISenseOption;
 
@@ -85,6 +86,16 @@ class DxcDefines {
   unsigned size() const { return DefineVector.size(); }
 };
 
+struct RewriterOpts {
+  bool Unchanged = false;                   // OPT_rw_unchanged
+  bool SkipFunctionBody = false;            // OPT_rw_skip_function_body
+  bool SkipStatic = false;                  // OPT_rw_skip_static
+  bool GlobalExternByDefault = false;       // OPT_rw_global_extern_by_default
+  bool KeepUserMacro = false;               // OPT_rw_keep_user_macro
+  bool ExtractEntryUniforms = false;        // OPT_rw_extract_entry_uniforms
+  bool RemoveUnusedGlobals = false;         // OPT_rw_remove_unused_globals
+};
+
 /// Use this class to capture all options.
 class DxcOpts {
 public:
@@ -174,6 +185,9 @@ class DxcOpts {
   unsigned long ValVerMajor = UINT_MAX, ValVerMinor = UINT_MAX; // OPT_validator_version
   unsigned ScanLimit = 0; // OPT_memdep_block_scan_limit
 
+  // Rewriter Options
+  RewriterOpts RWOpt;
+
   std::vector<std::string> Warnings;
 
   bool IsRootSignatureProfile();

include/dxc/Support/HLSLOptions.td

@@ -26,6 +26,9 @@ def CoreOption : OptionFlag;
 // ISenseOption - This option is only supported for IntelliSense.
 def ISenseOption : OptionFlag;
 
+// RewriteOption - This is considered a "rewriter" HLSL option.
+def RewriteOption : OptionFlag;
+
 //////////////////////////////////////////////////////////////////////////////
 // Groups
 
@@ -66,6 +69,7 @@ def hlslcomp_Group : OptionGroup<"HLSL Compilation">, HelpText<"Compilation Opti
 def hlsloptz_Group : OptionGroup<"HLSL Optimization">, HelpText<"Optimization Options">;
 def hlslutil_Group : OptionGroup<"HLSL Utility">, HelpText<"Utility Options">;
 def hlslcore_Group : OptionGroup<"HLSL Core">, HelpText<"Common Options">;
+def hlslrewrite_Group : OptionGroup<"HLSL Rewriter">, HelpText<"Rewriter Options">;
 
 def spirv_Group : OptionGroup<"SPIR-V CodeGen">, HelpText<"SPIR-V CodeGen Options">; // SPIRV Change
 
@@ -82,11 +86,11 @@ def spirv_Group : OptionGroup<"SPIR-V CodeGen">, HelpText<"SPIR-V CodeGen Option
 // The general approach is to include only things that are in use, in the
 // same order as in Options.td.
 
-def D : JoinedOrSeparate<["-", "/"], "D">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
+def D : JoinedOrSeparate<["-", "/"], "D">, Group<hlslcomp_Group>, Flags<[CoreOption, RewriteOption]>,
     HelpText<"Define macro">;
 def H : Flag<["-"], "H">, Flags<[CoreOption]>, Group<hlslcomp_Group>,
     HelpText<"Show header includes and nesting depth">;
-def I : JoinedOrSeparate<["-", "/"], "I">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
+def I : JoinedOrSeparate<["-", "/"], "I">, Group<hlslcomp_Group>, Flags<[CoreOption, RewriteOption]>,
     HelpText<"Add directory to include search path">;
 def O0 : Flag<["-", "/"], "O0">, Group<hlsloptz_Group>, Flags<[CoreOption]>,
     HelpText<"Optimization Level 0">;
@@ -212,13 +216,13 @@ def _help_question : Flag<["-", "/"], "?">, Flags<[DriverOption]>, Alias<help>;
 
 def ast_dump : Flag<["-", "/"], "ast-dump">, Flags<[CoreOption, DriverOption, HelpHidden]>,
   HelpText<"Dumps the parsed Abstract Syntax Tree.">; // should not be core, but handy workaround until explicit API written
-def external_lib : Separate<["-", "/"], "external">, Group<hlslcore_Group>, Flags<[DriverOption, HelpHidden]>,
+def external_lib : Separate<["-", "/"], "external">, Group<hlslcore_Group>, Flags<[DriverOption, RewriteOption, HelpHidden]>,
   HelpText<"External DLL name to load for compiler support">;
-def external_fn : Separate<["-", "/"], "external-fn">, Group<hlslcore_Group>, Flags<[DriverOption, HelpHidden]>,
+def external_fn : Separate<["-", "/"], "external-fn">, Group<hlslcore_Group>, Flags<[DriverOption, RewriteOption, HelpHidden]>,
   HelpText<"External function name to load for compiler support">;
 def fcgl : Flag<["-", "/"], "fcgl">, Group<hlslcore_Group>, Flags<[CoreOption, HelpHidden]>,
   HelpText<"Generate high-level code only">;
-def flegacy_macro_expansion : Flag<["-", "/"], "flegacy-macro-expansion">, Group<hlslcomp_Group>, Flags<[CoreOption, DriverOption]>,
+def flegacy_macro_expansion : Flag<["-", "/"], "flegacy-macro-expansion">, Group<hlslcomp_Group>, Flags<[CoreOption, RewriteOption, DriverOption]>,
     HelpText<"Expand the operands before performing token-pasting operation (fxc behavior)">;
 def flegacy_resource_reservation : Flag<["-", "/"], "flegacy-resource-reservation">, Group<hlslcomp_Group>, Flags<[CoreOption, DriverOption]>,
     HelpText<"Reserve unused explicit register assignments for compatibility with shader model 5.0 and below">;
@@ -234,13 +238,13 @@ def pack_optimized : Flag<["-", "/"], "pack-optimized">, Group<hlslcomp_Group>,
   HelpText<"Optimize signature packing assuming identical signature provided for each connecting stage">;
 def pack_optimized_ : Flag<["-", "/"], "pack_optimized">, Group<hlslcomp_Group>, Flags<[CoreOption, HelpHidden]>,
   HelpText<"Optimize signature packing assuming identical signature provided for each connecting stage">;
-def hlsl_version : Separate<["-", "/"], "HV">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
+def hlsl_version : Separate<["-", "/"], "HV">, Group<hlslcomp_Group>, Flags<[CoreOption, RewriteOption]>,
   HelpText<"HLSL version (2016, 2017, 2018). Default is 2018">;
-def no_warnings : Flag<["-", "/"], "no-warnings">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
+def no_warnings : Flag<["-", "/"], "no-warnings">, Group<hlslcomp_Group>, Flags<[CoreOption, RewriteOption]>,
   HelpText<"Suppress warnings">;
 def rootsig_define : Separate<["-", "/"], "rootsig-define">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
   HelpText<"Read root signature from a #define">;
-def enable_16bit_types: Flag<["-", "/"], "enable-16bit-types">, Flags<[CoreOption, DriverOption]>, Group<hlslcomp_Group>,
+def enable_16bit_types: Flag<["-", "/"], "enable-16bit-types">, Flags<[CoreOption, RewriteOption, DriverOption]>, Group<hlslcomp_Group>,
   HelpText<"Enable 16bit types and disable min precision types. Available in HLSL 2018 and shader model 6.2">;
 def ignore_line_directives : Flag<["-", "/"], "ignore-line-directives">, HelpText<"Ignore line directives">, Flags<[CoreOption]>, Group<hlslcomp_Group>;
 def auto_binding_space : Separate<["-", "/"], "auto-binding-space">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
@@ -251,7 +255,7 @@ def export_shaders_only : Flag<["-", "/"], "export-shaders-only">, Group<hlslcom
   HelpText<"Only export shaders when compiling a library">;
 def default_linkage : Separate<["-", "/"], "default-linkage">, Group<hlslcomp_Group>, Flags<[CoreOption]>,
   HelpText<"Set default linkage for non-shader functions when compiling or linking to a library target (internal, external)">;
-def encoding : Separate<["-", "/"], "encoding">, Group<hlslcomp_Group>, Flags<[CoreOption, DriverOption]>,
+def encoding : Separate<["-", "/"], "encoding">, Group<hlslcomp_Group>, Flags<[CoreOption, RewriteOption, DriverOption]>,
   HelpText<"Set default encoding for text outputs (utf8|utf16) default=utf8">;
 def validator_version : Separate<["-", "/"], "validator-version">, Group<hlslcomp_Group>, Flags<[CoreOption, HelpHidden]>,
   HelpText<"Override validator version for module.  Format: <major.minor> ; Default: DXIL.dll version or current internal version.">;
@@ -314,7 +318,7 @@ def target_profile : JoinedOrSeparate<["-", "/"], "T">, Flags<[CoreOption]>, Gro
   // VALRULE-TEXT:BEGIN
   HelpText<"Set target profile. \n\t<profile>: ps_6_0, ps_6_1, ps_6_2, ps_6_3, ps_6_4, ps_6_5, \n\t\t vs_6_0, vs_6_1, vs_6_2, vs_6_3, vs_6_4, vs_6_5, \n\t\t gs_6_0, gs_6_1, gs_6_2, gs_6_3, gs_6_4, gs_6_5, \n\t\t hs_6_0, hs_6_1, hs_6_2, hs_6_3, hs_6_4, hs_6_5, \n\t\t ds_6_0, ds_6_1, ds_6_2, ds_6_3, ds_6_4, ds_6_5, \n\t\t cs_6_0, cs_6_1, cs_6_2, cs_6_3, cs_6_4, cs_6_5, \n\t\t lib_6_1, lib_6_2, lib_6_3, lib_6_4, lib_6_5, \n\t\t ms_6_5, \n\t\t as_6_5, \n\t\t ">;
   // VALRULE-TEXT:END
-def entrypoint :  JoinedOrSeparate<["-", "/"], "E">, Flags<[CoreOption]>, Group<hlslcomp_Group>,
+def entrypoint :  JoinedOrSeparate<["-", "/"], "E">, Flags<[CoreOption, RewriteOption]>, Group<hlslcomp_Group>,
   HelpText<"Entry point name">;
 // /I <include> - already defined above
 def _vi : Flag<["-", "/"], "Vi">, Alias<H>, Flags<[CoreOption]>, Group<hlslcomp_Group>,
@@ -348,7 +352,7 @@ def Gis : Flag<["-", "/"], "Gis">, HelpText<"Force IEEE strictness">, Flags<[Cor
 
 def denorm : JoinedOrSeparate<["-", "/"], "denorm">, HelpText<"select denormal value options (any, preserve, ftz). any is the default.">, Flags<[CoreOption]>, Group<hlslcomp_Group>;
 
-def Fo : JoinedOrSeparate<["-", "/"], "Fo">, MetaVarName<"<file>">, HelpText<"Output object file">, Flags<[CoreOption, DriverOption]>, Group<hlslcomp_Group>;
+def Fo : JoinedOrSeparate<["-", "/"], "Fo">, MetaVarName<"<file>">, HelpText<"Output object file">, Flags<[CoreOption, RewriteOption, DriverOption]>, Group<hlslcomp_Group>;
 // def Fl : JoinedOrSeparate<["-", "/"], "Fl">, MetaVarName<"<file>">, HelpText<"Output a library">;
 def Fc : JoinedOrSeparate<["-", "/"], "Fc">, MetaVarName<"<file>">, HelpText<"Output assembly code listing file">, Flags<[DriverOption]>, Group<hlslcomp_Group>;
 //def Fx : JoinedOrSeparate<["-", "/"], "Fx">, MetaVarName<"<file>">, HelpText<"Output assembly code and hex listing file">;
@@ -426,5 +430,23 @@ def getprivate : JoinedOrSeparate<["-", "/"], "getprivate">, Flags<[DriverOption
 def nologo : Flag<["-", "/"], "nologo">, Group<hlslcore_Group>, Flags<[DriverOption]>,
   HelpText<"Suppress copyright message">;
 
+//////////////////////////////////////////////////////////////////////////////
+// Rewriter Options
+
+def rw_unchanged : Flag<["-", "/"], "unchanged">, Group<hlslrewrite_Group>, Flags<[RewriteOption]>,
+  HelpText<"Rewrite HLSL, without changes.">;
+def rw_skip_function_body : Flag<["-", "/"], "skip-fn-body">, Group<hlslrewrite_Group>, Flags<[RewriteOption]>,
+  HelpText<"Translate function definitions to declarations">;
+def rw_skip_static : Flag<["-", "/"], "skip-static">, Group<hlslrewrite_Group>, Flags<[RewriteOption]>,
+  HelpText<"Remove static functions and globals when used with -skip-fn-body">;
+def rw_global_extern_by_default : Flag<["-", "/"], "global-extern-by-default">, Group<hlslrewrite_Group>, Flags<[RewriteOption]>,
+  HelpText<"Set extern on non-static globals">;
+def rw_keep_user_macro : Flag<["-", "/"], "keep-user-macro">, Group<hlslrewrite_Group>, Flags<[RewriteOption]>,
+  HelpText<"Write out user defines after rewritten HLSL">;
+def rw_extract_entry_uniforms : Flag<["-", "/"], "extract-entry-uniforms">, Group<hlslrewrite_Group>, Flags<[RewriteOption]>,
+  HelpText<"Move uniform parameters from entry point to global scope">;
+def rw_remove_unused_globals : Flag<["-", "/"], "remove-unused-globals">, Group<hlslrewrite_Group>, Flags<[RewriteOption]>,
+  HelpText<"Remove unused static globals and functions">;
+
 // Also removed: compress, decompress, /Gch (child effect), /Gpp (partial precision)
 // /Op - no support for preshaders.

include/llvm/Option/OptTable.h

@@ -42,7 +42,7 @@ class OptTable {
     unsigned ID;
     unsigned char Kind;
     unsigned char Param;
-    unsigned short Flags;
+    unsigned long Flags;
     unsigned short GroupID;
     unsigned short AliasID;
     const char *AliasArgs;

lib/DxcSupport/HLSLOptions.cpp

@@ -680,7 +680,9 @@ int ReadDxcOpts(const OptTable *optionTable, unsigned flagsToInclude,
 
   // XXX TODO: Sort this out, since it's required for new API, but a separate argument for old APIs.
   if ((flagsToInclude & hlsl::options::DriverOption) &&
-      opts.TargetProfile.empty() && !opts.DumpBin && opts.Preprocess.empty() && !opts.RecompileFromBinary) {
+      !(flagsToInclude & hlsl::options::RewriteOption) &&
+      opts.TargetProfile.empty() && !opts.DumpBin && opts.Preprocess.empty() && !opts.RecompileFromBinary
+      ) {
     // Target profile is required in arguments only for drivers when compiling;
     // APIs take this through an argument.
     errors << "Target profile argument is missing";
@@ -880,6 +882,23 @@ int ReadDxcOpts(const OptTable *optionTable, unsigned flagsToInclude,
     return 1;
   }
 
+  // Rewriter Options
+  if (flagsToInclude & hlsl::options::RewriteOption) {
+    opts.RWOpt.Unchanged = Args.hasFlag(OPT_rw_unchanged, OPT_INVALID, false);
+    opts.RWOpt.SkipFunctionBody = Args.hasFlag(OPT_rw_skip_function_body, OPT_INVALID, false);
+    opts.RWOpt.SkipStatic = Args.hasFlag(OPT_rw_skip_static, OPT_INVALID, false);
+    opts.RWOpt.GlobalExternByDefault = Args.hasFlag(OPT_rw_global_extern_by_default, OPT_INVALID, false);
+    opts.RWOpt.KeepUserMacro = Args.hasFlag(OPT_rw_keep_user_macro, OPT_INVALID, false);
+    opts.RWOpt.ExtractEntryUniforms = Args.hasFlag(OPT_rw_extract_entry_uniforms, OPT_INVALID, false);
+    opts.RWOpt.RemoveUnusedGlobals = Args.hasFlag(OPT_rw_remove_unused_globals, OPT_INVALID, false);
+
+    if (opts.EntryPoint.empty() &&
+        (opts.RWOpt.RemoveUnusedGlobals || opts.RWOpt.ExtractEntryUniforms)) {
+      errors << "-rw-remove-unused-globals and -rw-extract-entry-uniforms requires entry point (-E) to be specified.";
+      return 1;
+    }
+  }
+
   opts.Args = std::move(Args);
   return 0;
 }

tools/clang/include/clang/AST/PrettyPrinter.h

@@ -43,7 +43,8 @@ struct PrintingPolicy {
       Bool(LO.Bool), TerseOutput(false), PolishForDeclaration(false),
       Half(LO.HLSL || LO.Half), // HLSL Change - always print 'half' for HLSL
       MSWChar(LO.MicrosoftExt && !LO.WChar),
-      IncludeNewlines(true) { }
+      IncludeNewlines(true),
+      HLSLSuppressUniformParameters(false) { }
 
   /// \brief What language we're printing.
   LangOptions LangOpts;
@@ -164,6 +165,11 @@ struct PrintingPolicy {
 
   /// \brief When true, include newlines after statements like "break", etc.
   unsigned IncludeNewlines : 1;
+
+  // HLSL Change Begin
+  /// \brief When true, exclude uniform function parameters
+  unsigned HLSLSuppressUniformParameters : 1;
+  // HLSL Change Ends
 };
 
 } // end namespace clang

tools/clang/lib/AST/DeclPrinter.cpp

@@ -510,6 +510,10 @@ void DeclPrinter::VisitFunctionDecl(FunctionDecl *D) {
       llvm::raw_string_ostream POut(Proto);
       DeclPrinter ParamPrinter(POut, SubPolicy, Indentation);
       for (unsigned i = 0, e = D->getNumParams(); i != e; ++i) {
+        if (Policy.HLSLSuppressUniformParameters &&
+            Policy.LangOpts.HLSL &&
+            D->getParamDecl(i)->hasAttr<HLSLUniformAttr>())  // HLSL Change
+          continue;
         if (i) POut << ", ";
         ParamPrinter.VisitParmVarDecl(D->getParamDecl(i));
       }

tools/clang/lib/Sema/SemaHLSL.cpp

@@ -12405,7 +12405,7 @@ void hlsl::CustomPrintHLSLAttr(const clang::Attr *A, llvm::raw_ostream &Out, con
     Attr * noconst = const_cast<Attr*>(A);
     HLSLRootSignatureAttr *ACast = static_cast<HLSLRootSignatureAttr*>(noconst);
     Indent(Indentation, Out);
-    Out << "[RootSignature(" << ACast->getSignatureName() << ")]\n";
+    Out << "[RootSignature(\"" << ACast->getSignatureName() << "\")]\n";
     break;
   }
 

tools/clang/test/HLSL/rewriter/correct_rewrites/array-length-rw_gold.hlsl

@@ -1,6 +1,6 @@
 // Rewrite unchanged result:
 const float4 planes[8];
-[RootSignature(CBV(b0, space=0, visibility=SHADER_VISIBILITY_ALL))]
+[RootSignature("CBV(b0, space=0, visibility=SHADER_VISIBILITY_ALL)")]
 float main() {
   float4 x = float4(1., 1., 1., 1.);
   for (uint i = 0; i < planes.Length; ++i) {

tools/clang/test/HLSL/rewriter/rewrite-uniforms.hlsl

@@ -0,0 +1,15 @@
+#define RS "RootFlags(0),DescriptorTable(UAV(u0, numDescriptors = 1), CBV(b0, numDescriptors = 1))"
+
+[RootSignature(RS)]
+[numthreads(4,8,16)]
+void FloatFunc(uint3 id : SV_DispatchThreadID, uniform RWStructuredBuffer<float> buf, uniform uint ui)
+{
+    buf[id.x+id.y+id.z] = id.x;
+}
+
+[RootSignature(RS)]
+[numthreads(4,8,16)]
+void IntFunc(uint3 id : SV_DispatchThreadID, uniform RWStructuredBuffer<int> buf, uniform uint ui)
+{
+    buf[id.x+id.y+id.z] = id.x + ui;
+}

tools/clang/tools/dxclib/dxc.cpp

@@ -1070,9 +1070,14 @@ bool GetDLLProductVersionInfo(const char *dllPath, std::string &productVersion)
   return false;
 }
 
-// Collects compiler/validator version info
-void DxcContext::GetCompilerVersionInfo(llvm::raw_string_ostream &OS) {
-  if (m_dxcSupport.IsEnabled()) {
+namespace dxc {
+
+// Writes compiler version info to stream
+void WriteDxCompilerVersionInfo(llvm::raw_ostream &OS,
+                                const char *ExternalLib,
+                                const char *ExternalFn,
+                                DxcDllSupport &DxcSupport) {
+  if (DxcSupport.IsEnabled()) {
     UINT32 compilerMajor = 1;
     UINT32 compilerMinor = 0;
     CComPtr<IDxcVersionInfo> VerInfo;
@@ -1083,10 +1088,12 @@ void DxcContext::GetCompilerVersionInfo(llvm::raw_string_ostream &OS) {
     CComPtr<IDxcVersionInfo2> VerInfo2;
 #endif // SUPPORT_QUERY_GIT_COMMIT_INFO
 
-    const char *compilerName =
-      m_Opts.ExternalFn.empty() ? "dxcompiler.dll" : m_Opts.ExternalFn.data();
+    const char *dllName = !ExternalLib ? "dxcompiler.dll" : ExternalLib;
+    std::string compilerName(dllName);
+    if (ExternalFn)
+      compilerName = compilerName + "!" + ExternalFn;
 
-    if (SUCCEEDED(CreateInstance(CLSID_DxcCompiler, &VerInfo))) {
+    if (SUCCEEDED(DxcSupport.CreateInstance(CLSID_DxcCompiler, &VerInfo))) {
       VerInfo->GetVersion(&compilerMajor, &compilerMinor);
 #ifdef SUPPORT_QUERY_GIT_COMMIT_INFO
       if (SUCCEEDED(VerInfo->QueryInterface(&VerInfo2)))
@@ -1095,13 +1102,16 @@ void DxcContext::GetCompilerVersionInfo(llvm::raw_string_ostream &OS) {
       OS << compilerName << ": " << compilerMajor << "." << compilerMinor;
     }
     // compiler.dll 1.0 did not support IdxcVersionInfo
-    else if (m_Opts.ExternalFn.empty()) {
+    else if (!ExternalLib) {
       OS << compilerName << ": " << 1 << "." << 0;
+    } else {
+      // ExternalLib/ExternalFn, no version info:
+      OS << compilerName;
     }
 
 #ifdef _WIN32
     unsigned int version[4];
-    if (GetDLLFileVersionInfo(compilerName, version)) {
+    if (GetDLLFileVersionInfo(dllName, version)) {
       // back-compat - old dev buidls had version 3.7.0.0
       if (version[0] == 3 && version[1] == 7 && version[2] == 0 && version[3] == 0) {
 #endif
@@ -1115,17 +1125,18 @@ void DxcContext::GetCompilerVersionInfo(llvm::raw_string_ostream &OS) {
       }
       else {
         std::string productVersion;
-        if (GetDLLProductVersionInfo(compilerName, productVersion)) {
+        if (GetDLLProductVersionInfo(dllName, productVersion)) {
           OS << " - " << productVersion;
         }
       }
     }
 #endif
   }
+}
 
-  // Print validator if exists
-  DxcDllSupport DxilSupport;
-  DxilSupport.InitializeForDll(L"dxil.dll", "DxcCreateInstance");
+// Writes compiler version info to stream
+void WriteDXILVersionInfo(llvm::raw_ostream &OS,
+                          DxcDllSupport &DxilSupport) {
   if (DxilSupport.IsEnabled()) {
     CComPtr<IDxcVersionInfo> VerInfo;
     if (SUCCEEDED(DxilSupport.CreateInstance(CLSID_DxcValidator, &VerInfo))) {
@@ -1149,6 +1160,21 @@ void DxcContext::GetCompilerVersionInfo(llvm::raw_string_ostream &OS) {
   }
 }
 
+} // namespace dxc
+
+// Collects compiler/validator version info
+void DxcContext::GetCompilerVersionInfo(llvm::raw_string_ostream &OS) {
+  WriteDxCompilerVersionInfo(OS,
+    m_Opts.ExternalLib.empty() ? nullptr : m_Opts.ExternalLib.data(),
+    m_Opts.ExternalFn.empty() ? nullptr : m_Opts.ExternalFn.data(),
+    m_dxcSupport);
+
+  // Print validator if exists
+  DxcDllSupport DxilSupport;
+  DxilSupport.InitializeForDll(L"dxil.dll", "DxcCreateInstance");
+  WriteDXILVersionInfo(OS, DxilSupport);
+}
+
 #ifndef VERSION_STRING_SUFFIX
 #define VERSION_STRING_SUFFIX ""
 #endif