Add slangc option to specialize entrypoint + auto glsl mode. (#3531)

* Add slangc option to specialize entrypoint.

* Auto enable glsl mode when input file has glsl extension name.

* Fix test.

---------

Co-authored-by: Yong He <yhe@nvidia.com>

7 files changed, 60 insertions, 28 deletions

diff --git a/source/slang/slang-ast-modifier.h b/source/slang/slang-ast-modifier.h
index 97487f131..53d13d1b5 100644
--- a/source/slang/slang-ast-modifier.h
+++ b/source/slang/slang-ast-modifier.h
@@ -32,7 +32,7 @@ class ConstExprModifier : public Modifier { SLANG_AST_CLASS(ConstExprModifier)};
 class GloballyCoherentModifier : public Modifier { SLANG_AST_CLASS(GloballyCoherentModifier)};
 class ExternCppModifier : public Modifier { SLANG_AST_CLASS(ExternCppModifier)};
 class GLSLPrecisionModifier : public Modifier { SLANG_AST_CLASS(GLSLPrecisionModifier)};
-
+class GLSLModuleModifier : public Modifier {SLANG_AST_CLASS(GLSLModuleModifier)};
 // Marks that the definition of a decl is not yet synthesized.
 class ToBeSynthesizedModifier : public Modifier {SLANG_AST_CLASS(ToBeSynthesizedModifier)};
 
diff --git a/source/slang/slang-check-modifier.cpp b/source/slang/slang-check-modifier.cpp
index 96ec0acc8..1a7f64944 100644
--- a/source/slang/slang-check-modifier.cpp
+++ b/source/slang/slang-check-modifier.cpp
@@ -1125,7 +1125,11 @@ namespace Slang
 
         if (auto decl = as<Decl>(syntaxNode))
         {
-            if (!isModifierAllowedOnDecl(getLinkage()->getAllowGLSLInput(), m->astNodeType, decl))
+            auto moduleDecl = getModuleDecl(decl);
+            bool isGLSLInput = getLinkage()->getAllowGLSLInput();
+            if (!isGLSLInput && moduleDecl && moduleDecl->findModifier<GLSLModuleModifier>())
+                isGLSLInput = true;
+            if (!isModifierAllowedOnDecl(isGLSLInput, m->astNodeType, decl))
             {
                 getSink()->diagnose(m, Diagnostics::modifierNotAllowed, m);
                 return m;
diff --git a/source/slang/slang-diagnostic-defs.h b/source/slang/slang-diagnostic-defs.h
index 9bad4b716..d0e188292 100644
--- a/source/slang/slang-diagnostic-defs.h
+++ b/source/slang/slang-diagnostic-defs.h
@@ -66,7 +66,6 @@ DIAGNOSTIC(    8, Error, outputPathsImplyDifferentFormats,
     "the output paths '$0' and '$1' require different code-generation targets")
 
 DIAGNOSTIC(    10, Error, explicitOutputPathsAndMultipleTargets, "canot use both explicit output paths ('-o') and multiple targets ('-target')")
-DIAGNOSTIC(    11, Error, glslIsNotSupported, "the Slang compiler does not support GLSL as a source language by default, please use -allow-glsl")
 DIAGNOSTIC(    12, Error, cannotDeduceSourceLanguage, "can't deduce language for input file '$0'")
 DIAGNOSTIC(    13, Error, unknownCodeGenerationTarget, "unknown code generation target '$0'")
 DIAGNOSTIC(    14, Error, unknownProfile, "unknown profile '$0'")
diff --git a/source/slang/slang-options.cpp b/source/slang/slang-options.cpp
index c9527bf5e..ae6195700 100644
--- a/source/slang/slang-options.cpp
+++ b/source/slang/slang-options.cpp
@@ -52,6 +52,7 @@ enum class OptionKind
     MacroDefine,
     DepFile,
     EntryPointName,
+    Specialize,
     Help,
     HelpStyle,
     Include,
@@ -393,6 +394,8 @@ void initCommandOptions(CommandOptions& options)
         "When they do, the file associated with the entry point will be the first one found when searching to the left in the command line.\n"
         "If no -entry options are given, compiler will use [shader(...)] "
         "attributes to detect entry points."},
+        { OptionKind::Specialize, "-specialize", "-specialize <typename>",
+            "Specialize the last entrypoint with <typename>.\n"},
         { OptionKind::EmitIr,       "-emit-ir", nullptr, "Emit IR typically as a '.slang-module' when outputting to a container." },
         { OptionKind::Help,         "-h,-help,--help", "-h or -h <help-category>", "Print this message, or help in specified category." },
         { OptionKind::HelpStyle,    "-help-style", "-help-style <help-style>", "Help formatting style" },
@@ -744,7 +747,7 @@ struct OptionsParser
         Stage   stage = Stage::Unknown;
         int     translationUnitIndex = -1;
         int     entryPointID = -1;
-
+        List<String> specializationArgs;
         // State for tracking command-line errors
         bool conflictingStagesSet = false;
         bool redundantStageSet = false;
@@ -786,8 +789,6 @@ struct OptionsParser
 
     static Profile::RawVal findGlslProfileFromPath(const String& path);
 
-    static SlangSourceLanguage findSourceLanguageFromPath(const String& path, Stage& outImpliedStage);
-
     SlangResult addInputPath(char const* inPath, SourceLanguage langOverride = SourceLanguage::Unknown);
 
     void addOutputPath(String const& path, CodeGenTarget impliedFormat);
@@ -1007,7 +1008,7 @@ void OptionsParser::addInputForeignShaderPath(
     return Profile::Unknown;
 }
 
-/* static */SlangSourceLanguage OptionsParser::findSourceLanguageFromPath(const String& path, Stage& outImpliedStage)
+SlangSourceLanguage findSourceLanguageFromPath(const String& path, Stage& outImpliedStage)
 {
     struct Entry
     {
@@ -1032,6 +1033,12 @@ void OptionsParser::addInputForeignShaderPath(
         { ".comp", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_COMPUTE },
         { ".mesh", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_MESH },
         { ".task", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_AMPLIFICATION },
+        { ".rgen", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_RAY_GENERATION },
+        { ".rint", SLANG_SOURCE_LANGUAGE_GLSL,  SLANG_STAGE_INTERSECTION },
+        { ".rahit", SLANG_SOURCE_LANGUAGE_GLSL, SLANG_STAGE_ANY_HIT },
+        { ".rchit", SLANG_SOURCE_LANGUAGE_GLSL, SLANG_STAGE_CLOSEST_HIT },
+        { ".rmiss", SLANG_SOURCE_LANGUAGE_GLSL, SLANG_STAGE_MISS },
+        { ".rcall", SLANG_SOURCE_LANGUAGE_GLSL, SLANG_STAGE_CALLABLE },
 
         { ".c",    SLANG_SOURCE_LANGUAGE_C,     SLANG_STAGE_NONE },
         { ".cpp",  SLANG_SOURCE_LANGUAGE_CPP,   SLANG_STAGE_NONE },
@@ -2179,6 +2186,24 @@ SlangResult OptionsParser::_parse(
                 m_rawEntryPoints.add(rawEntryPoint);
                 break;
             }
+            case OptionKind::Specialize:
+            {
+                for (;;)
+                {
+                    CommandLineArg name;
+                    SLANG_RETURN_ON_FAIL(m_reader.expectArg(name));
+                    if (m_rawEntryPoints.getCount() > 0)
+                    {
+                        auto& lastEntryPoint = m_rawEntryPoints.getLast();
+                        lastEntryPoint.specializationArgs.add(name.value);
+                    }
+                    if (m_reader.hasArg() && m_reader.peekArg().value == ",")
+                        m_reader.advance();
+                    else
+                        break;
+                }
+                break;
+            }
             case OptionKind::Language:
             {
                 CommandLineArg name;
@@ -2668,10 +2693,16 @@ SlangResult OptionsParser::_parse(
 
         auto translationUnitID = m_rawTranslationUnits[rawEntryPoint.translationUnitIndex].translationUnitID;
 
-        int entryPointID = m_compileRequest->addEntryPoint(
+        List<const char*> specializationArgs;
+        for (auto& arg : rawEntryPoint.specializationArgs)
+            specializationArgs.add(arg.getBuffer());
+
+        int entryPointID = m_compileRequest->addEntryPointEx(
             translationUnitID,
             rawEntryPoint.name.begin(),
-            SlangStage(rawEntryPoint.stage));
+            SlangStage(rawEntryPoint.stage),
+            (int)specializationArgs.getCount(),
+            specializationArgs.getBuffer());
 
         rawEntryPoint.entryPointID = entryPointID;
     }
diff --git a/source/slang/slang-options.h b/source/slang/slang-options.h
index bb05312a3..92c11a88a 100644
--- a/source/slang/slang-options.h
+++ b/source/slang/slang-options.h
@@ -19,5 +19,9 @@ SlangResult parseOptions(
 // Initialize command options. Holds the details how parsing works. 
 void initCommandOptions(CommandOptions& commandOptions);
 
+enum class Stage : SlangUInt32;
+
+SlangSourceLanguage findSourceLanguageFromPath(const String& path, Stage& outImpliedStage);
+
 }
 #endif
diff --git a/source/slang/slang-parser.cpp b/source/slang/slang-parser.cpp
index f5312e645..a086b3c7a 100644
--- a/source/slang/slang-parser.cpp
+++ b/source/slang/slang-parser.cpp
@@ -4650,6 +4650,8 @@ namespace Slang
                 importDecl->scope = currentScope;
                 AddMember(currentScope, importDecl);
             }
+            auto glslModuleModifier = astBuilder->create<GLSLModuleModifier>();
+            addModifier(currentModule, glslModuleModifier);
         }
 
         parseDecls(this, program, MatchedTokenType::File);
@@ -7360,7 +7362,8 @@ namespace Slang
     {
         ParserOptions options = {};
         options.enableEffectAnnotations = translationUnit->compileRequest->getLinkage()->getEnableEffectAnnotations();
-        options.allowGLSLInput = translationUnit->compileRequest->getLinkage()->getAllowGLSLInput();
+        options.allowGLSLInput = translationUnit->compileRequest->getLinkage()->getAllowGLSLInput() ||
+            translationUnit->sourceLanguage == SourceLanguage::GLSL;
         options.isInLanguageServer = translationUnit->compileRequest->getLinkage()->isInLanguageServer();
 
         Parser parser(astBuilder, tokens, sink, outerScope, options);
diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index 8eb75c119..a027340b5 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -25,7 +25,6 @@
 #include "slang-mangle.h"
 #include "slang-parser.h"
 #include "slang-preprocessor.h"
-
 #include "slang-type-layout.h"
 
 #include "slang-options.h"
@@ -2601,23 +2600,6 @@ SlangResult FrontEndCompileRequest::executeActionsInner()
     {
         // Make sure SourceFile representation is available for all translationUnits
         SLANG_RETURN_ON_FAIL(translationUnit->requireSourceFiles());
-
-        if(!getLinkage()->getAllowGLSLInput())
-        {
-            // We currently allow GlSL files on the command line so that we can
-            // drive our "pass-through" mode, but we really want to issue an error
-            // message if the user is seriously asking us to compile them and
-            // doesn't explicitly opt into the glsl frontend
-            switch(translationUnit->sourceLanguage)
-            {
-            default:
-                break;
-
-            case SourceLanguage::GLSL:
-                getSink()->diagnose(SourceLoc(), Diagnostics::glslIsNotSupported);
-                return SLANG_FAIL;
-            }
-        }
     }
 
 
@@ -3138,8 +3120,17 @@ RefPtr<Module> Linkage::loadModule(
     RefPtr<TranslationUnitRequest> translationUnit = new TranslationUnitRequest(frontEndReq);
     translationUnit->compileRequest = frontEndReq;
     translationUnit->moduleName = name;
+    Stage impliedStage;
     translationUnit->sourceLanguage = SourceLanguage::Slang;
 
+    // If we are loading from a file with apparaent glsl extension,
+    // set the source language to GLSL to enable GLSL compatibility mode.
+    if ((SourceLanguage)findSourceLanguageFromPath(filePathInfo.getName(), impliedStage) ==
+        SourceLanguage::GLSL)
+    {
+        translationUnit->sourceLanguage = SourceLanguage::GLSL;
+    }
+    
     frontEndReq->addTranslationUnit(translationUnit);
 
     auto module = translationUnit->getModule();