Vulkan implicit sampler fixups (#686)

* Fix sampler-less texture functions (#685)

* Fix sampler-less texeture functions

I'm honestly not sure how the original work on this feature in #648 worked at all (probably insufficient testing).

We have these front-end modifiers to indicate that a particular function definition requires a certain GLSL version, or a GLSL extension in order to be used, and they are supposed to be automatically employed by the logic in `emit.cpp` to output `#extension` lines in the output GLSL. However, it turns out that nothing is actually wired up right now, so that adding the modifiers to a declaration is a placebo.

This change propagates the modifiers through as decorations, and then uses them during GLSL code emit, which allows the functions that require `EXT_samplerless_texture_functions` to work.

* fixup: 32-bit warning

* Add serialization support for GLSL extension/version decorations

1 files changed, 30 insertions, 0 deletions

diff --git a/source/slang/ir-serialize.cpp b/source/slang/ir-serialize.cpp
index 3b0e45e23..e204944a7 100644
--- a/source/slang/ir-serialize.cpp
+++ b/source/slang/ir-serialize.cpp
@@ -531,6 +531,22 @@ Result IRSerialWriter::write(IRModule* module, SourceManager* sourceManager, Opt
                     dstInst.m_payloadType = PayloadType::Empty;
                     break;
                 }
+                case kIRDecorationOp_RequireGLSLExtension:
+                {
+                    auto extDecor = static_cast<IRRequireGLSLExtensionDecoration*>(srcDecor);
+
+                    dstInst.m_payloadType = PayloadType::String_1;
+                    dstInst.m_payload.m_stringIndices[0] = getStringIndex(extDecor->extensionName);
+                    break;
+                }
+                case kIRDecorationOp_RequireGLSLVersion:
+                {
+                    auto verDecor = static_cast<IRRequireGLSLVersionDecoration*>(srcDecor);
+
+                    dstInst.m_payloadType = PayloadType::UInt32;
+                    dstInst.m_payload.m_uint32 = uint32_t(verDecor->languageVersion);
+                    break;
+                }
                 default:
                 {
                     SLANG_ASSERT(!"Unhandled decoration type");
@@ -1513,6 +1529,20 @@ IRDecoration* IRSerialReader::_createDecoration(const Ser::Inst& srcInst)
             SLANG_ASSERT(srcInst.m_payloadType == PayloadType::Empty);
             return decor;
         }
+        case kIRDecorationOp_RequireGLSLExtension:
+        {
+            auto decor = createEmptyDecoration<IRRequireGLSLExtensionDecoration>(m_module);
+            SLANG_ASSERT(srcInst.m_payloadType == PayloadType::String_1);
+            decor->extensionName = getStringRepresentation(srcInst.m_payload.m_stringIndices[0]);
+            return decor;
+        }
+        case kIRDecorationOp_RequireGLSLVersion:
+        {
+            auto decor = createEmptyDecoration<IRRequireGLSLVersionDecoration>(m_module);
+            SLANG_ASSERT(srcInst.m_payloadType == Ser::Inst::PayloadType::UInt32);
+            decor->languageVersion = Int(srcInst.m_payload.m_uint32);
+            return decor;
+        }
         default:
         {
             SLANG_ASSERT(!"Unhandled decoration type");