Implement explciit binding for metal and wgsl. (#5778)

* Respect explicit bindings in wgsl emit.

* Implement explciit binding generation for metal and wgsl.

* Update toc.

* Fix warnings in tests.

* Fix tests.

---------

Co-authored-by: Ellie Hermaszewska <ellieh@nvidia.com>

1 files changed, 17 insertions, 2 deletions

diff --git a/source/slang/slang-parameter-binding.cpp b/source/slang/slang-parameter-binding.cpp
index e45eb4652..f9c4f0c94 100644
--- a/source/slang/slang-parameter-binding.cpp
+++ b/source/slang/slang-parameter-binding.cpp
@@ -984,7 +984,8 @@ static void addExplicitParameterBindings_HLSL(
     //
     // For now we do the filtering on target in a very direct fashion:
     //
-    if (!isD3DTarget(context->getTargetRequest()) && !isMetalTarget(context->getTargetRequest()))
+    bool isMetal = isMetalTarget(context->getTargetRequest());
+    if (!isD3DTarget(context->getTargetRequest()) && !isMetal)
         return;
 
     auto typeLayout = varLayout->typeLayout;
@@ -1018,6 +1019,7 @@ static void addExplicitParameterBindings_HLSL(
         if (kind == LayoutResourceKind::None)
             continue;
 
+
         // TODO: need to special-case when this is a `c` register binding...
 
         // Find the appropriate resource-binding information
@@ -1025,6 +1027,19 @@ static void addExplicitParameterBindings_HLSL(
         // of the given kind.
 
         auto typeRes = typeLayout->FindResourceInfo(kind);
+        if (isMetal && !typeRes)
+        {
+            // Metal doesn't distinguish a unordered access and a readonly/uniform buffer.
+            switch (kind)
+            {
+            case LayoutResourceKind::UnorderedAccess:
+            case LayoutResourceKind::ShaderResource:
+                semanticInfo.kind = LayoutResourceKind::MetalBuffer;
+                typeRes = typeLayout->FindResourceInfo(LayoutResourceKind::MetalBuffer);
+                break;
+            }
+        }
+
         LayoutSize count = 0;
         if (typeRes)
         {
@@ -1073,7 +1088,7 @@ static void addExplicitParameterBindings_GLSL(
     // so that we are able to distinguish between
     // Vulkan and OpenGL as targets.
     //
-    if (!isKhronosTarget(context->getTargetRequest()))
+    if (!isKhronosTarget(context->getTargetRequest()) && !isWGPUTarget(context->getTargetRequest()))
         return;
 
     auto typeLayout = varLayout->typeLayout;