Discover entry points specified via options

This closes #6452.

Author: aleino-nv

source/slang/slang-compiler.cpp

@@ -2745,11 +2745,49 @@ void Module::_discoverEntryPoints(DiagnosticSink* sink, const List<RefPtr<Target
         return;
     _discoverEntryPointsImpl(m_moduleDecl, sink, targets);
 }
+
+static void addEntryPointStagesFromOptions(
+    Slang::CompilerOptionSet& optionSet,
+    Dictionary<String, Stage>& optionEntryPointStages)
+{
+    for (auto& entry : optionSet.options)
+    {
+        if (entry.key != CompilerOptionName::EntryPointName)
+            continue;
+
+        for (auto& value : entry.value)
+        {
+            // Assume the options have been validated
+            SLANG_ASSERT(value.kind == CompilerOptionValueKind::String);
+            Stage stage = optionSet.getEnumOption<Stage>(CompilerOptionName::Stage);
+            if (stage != Stage::Unknown)
+            {
+                // We're assuming option validation forbids inconsistent entry points
+                Stage existingStage;
+                SLANG_ASSERT(
+                    !optionEntryPointStages.tryGetValue(value.stringValue, existingStage) ||
+                    existingStage == stage);
+                optionEntryPointStages.add(value.stringValue, stage);
+                break;
+            }
+        }
+    }
+}
+
 void Module::_discoverEntryPointsImpl(
     ContainerDecl* containerDecl,
     DiagnosticSink* sink,
     const List<RefPtr<TargetRequest>>& targets)
 {
+    // Get entry points from global and per-target compiler options
+    Dictionary<String, Stage> optionEntryPointStages;
+    addEntryPointStagesFromOptions(getLinkage()->m_optionSet, optionEntryPointStages);
+    for (auto target : targets)
+    {
+        auto& targetOptionSet = target->getOptionSet();
+        addEntryPointStagesFromOptions(targetOptionSet, optionEntryPointStages);
+    }
+
     for (auto globalDecl : containerDecl->members)
     {
         auto maybeFuncDecl = globalDecl;
@@ -2776,7 +2814,20 @@ void Module::_discoverEntryPointsImpl(
             targets,
             funcDecl,
             sink);
+
+        // Check if this function is marked as an entry point via compiler options
+        bool resolvedStageOfProfileWithOptions = false;
         if (!resolvedStageOfProfileWithEntryPoint)
+        {
+            Stage stage;
+            if (optionEntryPointStages.tryGetValue(funcDecl->getName()->text, stage))
+            {
+                profile.setStage(stage);
+                resolvedStageOfProfileWithOptions = true;
+            }
+        }
+
+        if (!resolvedStageOfProfileWithEntryPoint && !resolvedStageOfProfileWithOptions)
         {
             // If there isn't a [shader] attribute, look for a [numthreads] attribute
             // since that implicitly means a compute shader. We'll not do this when compiling for