Allow specializing entrypoints with generic value args or variadic types from API (#8119)

Closes #8110.
Closes #8011.

1 files changed, 42 insertions, 28 deletions

diff --git a/source/slang/slang-linkable.cpp b/source/slang/slang-linkable.cpp
index f7dc28171..0eef62742 100644
--- a/source/slang/slang-linkable.cpp
+++ b/source/slang/slang-linkable.cpp
@@ -371,9 +371,19 @@ RefPtr<ComponentType> ComponentType::specialize(
     // (e.g., interface conformance witnesses) that doesn't get
     // passed explicitly through the API interface.
     //
-    RefPtr<SpecializationInfo> specializationInfo =
-        _validateSpecializationArgs(specializationArgs.getBuffer(), specializationArgCount, sink);
-
+    Index consumedArgCount = 0;
+    RefPtr<SpecializationInfo> specializationInfo = _validateSpecializationArgs(
+        specializationArgs.getBuffer(),
+        specializationArgCount,
+        consumedArgCount,
+        sink);
+    if (consumedArgCount != specializationArgCount)
+    {
+        sink->diagnose(
+            SourceLoc(),
+            Diagnostics::mismatchSpecializationArguments,
+            Math::Max(consumedArgCount, getSpecializationParamCount(), specializationArgCount));
+    }
     return new SpecializedComponentType(this, specializationInfo, specializationArgs, sink);
 }
 
@@ -385,21 +395,6 @@ SLANG_NO_THROW SlangResult SLANG_MCALL ComponentType::specialize(
 {
     DiagnosticSink sink(getLinkage()->getSourceManager(), Lexer::sourceLocationLexer);
 
-    // First let's check if the number of arguments given matches
-    // the number of parameters that are present on this component type.
-    //
-    auto specializationParamCount = getSpecializationParamCount();
-    if (specializationArgCount != specializationParamCount)
-    {
-        sink.diagnose(
-            SourceLoc(),
-            Diagnostics::mismatchSpecializationArguments,
-            specializationParamCount,
-            specializationArgCount);
-        sink.getBlobIfNeeded(outDiagnostics);
-        return SLANG_FAIL;
-    }
-
     List<SpecializationArg> expandedArgs;
     for (Int aa = 0; aa < specializationArgCount; ++aa)
     {
@@ -411,7 +406,21 @@ SLANG_NO_THROW SlangResult SLANG_MCALL ComponentType::specialize(
         case slang::SpecializationArg::Kind::Type:
             expandedArg.val = asInternal(apiArg.type);
             break;
-
+        case slang::SpecializationArg::Kind::Expr:
+            {
+                auto parsedExpr = parseExprFromString(apiArg.expr, &sink);
+                if (!parsedExpr)
+                    return SLANG_FAIL;
+
+                SharedSemanticsContext sharedSemanticsContext(getLinkage(), nullptr, &sink);
+                SemanticsVisitor visitor(&sharedSemanticsContext);
+                auto checkedExpr = visitor.CheckTerm(parsedExpr);
+                if (auto typeType = as<TypeType>(checkedExpr->type.type))
+                    expandedArg.val = typeType->getType();
+                else
+                    expandedArg.expr = checkedExpr;
+            }
+            break;
         default:
             sink.getBlobIfNeeded(outDiagnostics);
             return SLANG_FAIL;
@@ -425,7 +434,8 @@ SLANG_NO_THROW SlangResult SLANG_MCALL ComponentType::specialize(
     sink.getBlobIfNeeded(outDiagnostics);
 
     *outSpecializedComponentType = specializedComponentType.detach();
-
+    if (sink.getErrorCount() != 0)
+        return SLANG_FAIL;
     return SLANG_OK;
 }
 
@@ -729,6 +739,18 @@ SLANG_NO_THROW SlangResult SLANG_MCALL ComponentType::getTargetMetadata(
     return SLANG_OK;
 }
 
+Expr* ComponentType::parseExprFromString(String exprStr, DiagnosticSink* sink)
+{
+    auto linkage = getLinkage();
+    SLANG_AST_BUILDER_RAII(linkage->getASTBuilder());
+    auto astBuilder = linkage->getASTBuilder();
+    Scope* scope = _getOrCreateScopeForLegacyLookup(astBuilder);
+    Expr* expr = linkage->parseTermString(exprStr, scope);
+    if (!expr || as<IncompleteExpr>(expr))
+        sink->diagnose(SourceLoc(), Diagnostics::syntaxError);
+    return expr;
+}
+
 Type* ComponentType::getTypeFromString(String const& typeStr, DiagnosticSink* sink)
 {
     // If we've looked up this type name before,
@@ -738,14 +760,6 @@ Type* ComponentType::getTypeFromString(String const& typeStr, DiagnosticSink* si
     if (m_types.tryGetValue(typeStr, type))
         return type;
 
-
-    // TODO(JS): For now just used the linkages ASTBuilder to keep on scope
-    //
-    // The parseTermString uses the linkage ASTBuilder for it's parsing.
-    //
-    // It might be possible to just create a temporary ASTBuilder - the worry though is
-    // that the parsing sets a member variable in AST node to one of these scopes, and then
-    // it become a dangling pointer. So for now we go with the linkages.
     auto astBuilder = getLinkage()->getASTBuilder();
 
     // Otherwise, we need to start looking in