Pointer layout support (#2930)

* WIP looking at reflection with pointers.

* Added GetPointerLayout.

* Initial test via reflection with layout of ptr type.

* WIP handles ptrs to types that have layout that hasn't been completed.

* Move tests to ptr.

* WIP try to take into account lowering correctly between AggTypeDecl and Type, but doesn't quite work.

* WIP a different path to handling recursive lowering problem with Ptr.

* Fix issues with reflection output.

* Small tidy.

* Fix for infinite recursion issue.

* Lower IRPointerTypeLayout

* Working with generics.
Has a hack to work around Layout around Ptr in IR.
The reflection around the generic - the name isn't much use, it should probably have the generic parameters, but that would require getName to do something more sophisticated.

* Fix issue around calling finishOuterGenerics to early.

* Remove feature/ptr test.

* Fix type legalization being an infinite loop with Ptr self referencing.

* Disable the pointer self reference test because produces an infintie loop on emit.

* Fixed comment based on review.

* Fix for issue with emit and pointers causing infinite recursion.

3 files changed, 53 insertions, 0 deletions

diff --git a/tools/gfx/cpu/cpu-device.cpp b/tools/gfx/cpu/cpu-device.cpp
index 0db2b0fa7..4b8595e82 100644
--- a/tools/gfx/cpu/cpu-device.cpp
+++ b/tools/gfx/cpu/cpu-device.cpp
@@ -45,6 +45,11 @@ namespace cpu
             m_info.timestampFrequency = 1000000000;
         }
 
+        // Can support pointers (or something akin to that)
+        {
+            m_features.add("has-ptr");
+        }
+
         return SLANG_OK;
     }
 
diff --git a/tools/gfx/cuda/cuda-device.cpp b/tools/gfx/cuda/cuda-device.cpp
index bbf50cc58..7f931afa1 100644
--- a/tools/gfx/cuda/cuda-device.cpp
+++ b/tools/gfx/cuda/cuda-device.cpp
@@ -185,6 +185,9 @@ SLANG_NO_THROW SlangResult SLANG_MCALL DeviceImpl::initialize(const Desc& desc)
         
         // CUDA has support for realtime clock
         m_features.add("realtime-clock");
+
+        // Allows use of a ptr like type
+        m_features.add("has-ptr");
     }
 
     cudaDeviceProp deviceProps;
diff --git a/tools/slang-reflection-test/slang-reflection-test-main.cpp b/tools/slang-reflection-test/slang-reflection-test-main.cpp
index 94062cf2b..cd726eb59 100644
--- a/tools/slang-reflection-test/slang-reflection-test-main.cpp
+++ b/tools/slang-reflection-test/slang-reflection-test-main.cpp
@@ -292,6 +292,7 @@ static void emitReflectionVarBindingInfoJSON(
     CASE(MIXED, mixed);
     CASE(REGISTER_SPACE, registerSpace);
     CASE(GENERIC, generic);
+
     #undef CASE
 
         default:
@@ -769,6 +770,16 @@ static void emitReflectionTypeInfoJSON(
             emitReflectionTypeJSON(writer, arrayType->getElementType());
         }
         break;
+    case slang::TypeReflection::Kind::Pointer:
+        {
+            auto pointerType = type;
+            writer.maybeComma();
+            writer << "\"kind\": \"pointer\"";
+            writer.maybeComma();
+            writer << "\"targetType\": ";
+            emitReflectionTypeJSON(writer, pointerType->getElementType());
+        }
+        break;
 
     case slang::TypeReflection::Kind::Struct:
         {
@@ -888,6 +899,40 @@ static void emitReflectionTypeLayoutInfoJSON(
         emitReflectionTypeInfoJSON(writer, typeLayout->getType());
         break;
 
+    case slang::TypeReflection::Kind::Pointer:
+        {
+            auto valueTypeLayout = typeLayout->getElementTypeLayout();
+            SLANG_ASSERT(valueTypeLayout);
+
+            writer.maybeComma();
+            writer << "\"kind\": \"pointer\"";
+
+            writer.maybeComma();
+            writer << "\"valueType\": ";
+
+            auto typeName = valueTypeLayout->getType()->getName();
+
+            if (typeName && typeName[0])
+            {
+                // TODO(JS):
+                // We can't emit the type layout, because the type could contain
+                // a pointer and we end up in a recursive loop. For now we output the typename.
+                writer.writeEscapedString(UnownedStringSlice(typeName));
+            }
+            else
+            {
+                // TODO(JS): We will need to generate name that we will associate with this type 
+                // as it doesn't seem to have one
+                writer.writeEscapedString(toSlice("unknown name!"));
+                SLANG_ASSERT(!"Doesn't have an associated name");
+            }
+
+            /*
+            emitReflectionTypeLayoutJSON(
+                writer,
+                valueTypeLayout); */
+        }
+        break;
     case slang::TypeReflection::Kind::Array:
         {
             auto arrayTypeLayout = typeLayout;