Change how DeclRef::toText works (shader-slang#5592)

* Change how DeclRef::toText works

We now ignore the decl-ref heirarchy since that only includes nodes with specialization info & simply walk up the tree of decls, while emitting any specializations present in the decl-ref.

* Update some tests. Add cases for direct refs to generic params & Lookup decl refs

Author: saipraveenb25

external/vulkan

@@ -312,7 +312,82 @@ DeclRefBase* DeclRefBase::getBase()
 }
 void DeclRefBase::toText(StringBuilder& out)
 {
-    SLANG_AST_NODE_VIRTUAL_CALL(DeclRefBase, toText, (out));
+    if (auto lookupDeclRef = as<LookupDeclRef>(this))
+    {
+        lookupDeclRef->_toTextOverride(out);
+        return;
+    }
+
+    if (as<GenericTypeParamDecl>(this->getDecl()))
+    {
+        SLANG_ASSERT(as<DirectDeclRef>(this));
+        out << this->getDecl()->getName()->text;
+        return;
+    }
+    else if (as<GenericValueParamDecl>(this->getDecl()))
+    {
+        SLANG_ASSERT(as<DirectDeclRef>(this));
+        out << this->getDecl()->getName()->text;
+        return;
+    }
+
+    SubstitutionSet substSet(this);
+
+    List<Decl*> decls;
+    for (auto dd = getDecl(); dd; dd = dd->parentDecl)
+    {
+        // Skip the top-level decl.
+        if (as<ModuleDecl>(dd))
+            continue;
+
+        // Skip base decls in generic containers. We will handle them when we handle the generic
+        // decl.
+        //
+        if (dd->parentDecl && as<GenericDecl>(dd->parentDecl))
+            continue;
+
+        decls.add(dd);
+    }
+
+    decls.reverse();
+
+    bool first = true;
+    for (auto decl : decls)
+    {
+        if (!first)
+            out << ".";
+        first = false;
+
+        if (auto name = decl->getName())
+        {
+            out << name->text;
+
+            // If there are any specializations for this decl, emit them here:
+            if (auto genericDecl = as<GenericDecl>(decl))
+            {
+                if (auto genericAppDeclRef = substSet.findGenericAppDeclRef(genericDecl))
+                {
+                    Index paramCount = 0;
+                    for (auto member : genericDecl->members)
+                        if (as<GenericTypeParamDeclBase>(member) ||
+                            as<GenericValueParamDecl>(member))
+                            paramCount++;
+                    out << "<";
+                    auto args = genericAppDeclRef->getArgs();
+                    Index argCount = args.getCount();
+                    for (Index aa = 0; aa < Math::Min(paramCount, argCount); ++aa)
+                    {
+                        if (aa != 0)
+                            out << ", ";
+                        args[aa]->toText(out);
+                    }
+                    out << ">";
+                }
+            }
+
+            // TODO: What do we do about extensions?
+        }
+    }
 }
 
 Name* DeclRefBase::getName() const

source/slang/slang-ast-decl-ref.cpp

@@ -15,13 +15,13 @@ tests/diagnostics/mismatching-types.slang(57): error 30019: expected an expressi
 tests/diagnostics/mismatching-types.slang(59): error 30019: expected an expression of type 'GenericOuter<int>.NonGenericInner', got 'GenericOuter<float>.NonGenericInner'
     a.ng = b.ng;
              ^~
-tests/diagnostics/mismatching-types.slang(61): error 30019: expected an expression of type 'GenericInner<int>', got 'int'
+tests/diagnostics/mismatching-types.slang(61): error 30019: expected an expression of type 'NonGenericOuter.GenericInner<int>', got 'int'
     c.i = 0;
           ^
-tests/diagnostics/mismatching-types.slang(63): error 30019: expected an expression of type 'GenericInner<int>', got 'GenericInner<float>'
+tests/diagnostics/mismatching-types.slang(63): error 30019: expected an expression of type 'NonGenericOuter.GenericInner<int>', got 'NonGenericOuter.GenericInner<float>'
     c.i = c.f;
             ^
-tests/diagnostics/mismatching-types.slang(65): error 30019: expected an expression of type 'GenericInner<int>.ReallyNested', got 'int'
+tests/diagnostics/mismatching-types.slang(65): error 30019: expected an expression of type 'NonGenericOuter.GenericInner<int>.ReallyNested', got 'int'
     c.i.n = 0;
             ^
 tests/diagnostics/mismatching-types.slang(74): error 30019: expected an expression of type 'Texture1D<int>', got 'Texture1D<float>'

tests/diagnostics/mismatching-types.slang.expected

@@ -242,7 +242,6 @@ SLANG_UNIT_TEST(declTreeReflection)
     {
         auto type = compositeProgram->getLayout()->findTypeByName("MyGenericType<half>");
         SLANG_CHECK(type != nullptr);
-        // SLANG_CHECK(type->getKind() == slang::DeclReflection::Kind::Struct);
         SLANG_CHECK(getTypeFullName(type) == "MyGenericType<half>");
         auto funcReflection = compositeProgram->getLayout()->findFunctionByNameInType(type, "g");
         SLANG_CHECK(funcReflection != nullptr);
@@ -485,6 +484,12 @@ SLANG_UNIT_TEST(declTreeReflection)
         SLANG_CHECK(getTypeFullName(specializedMethodWithFloat->getReturnType()) == "float");
     }
 
+    // Check getTypeFullName() on nested objects.
+    {
+        auto structType = compositeProgram->getLayout()->findTypeByName("MyNamespace::MyStruct");
+        SLANG_CHECK(getTypeFullName(structType) == "MyNamespace.MyStruct");
+    }
+
     // Check iterators
     {
         unsigned int count = 0;