From dfab34e4bf508fc517d4d645ebb3b6b1179a5003 Mon Sep 17 00:00:00 2001
From: Anders Leino <aleino@nvidia.com>
Date: Fri, 11 Oct 2024 13:13:04 +0300
Subject: Add slang-wasm target (#5237)

Support for exceptions is enabled, since Slang uses them for diagnostics.
The size optimization arguments ('-Os') resolves some internal emscripten error during the
slang-wasm.wasm linking step, which happens when enabling exceptions.
("parse exception: too many locals")
---
 source/slang-wasm/slang-wasm.cpp | 182 +++++++++++++++++++++++++++++++++++++++
 1 file changed, 182 insertions(+)
 create mode 100644 source/slang-wasm/slang-wasm.cpp

(limited to 'source/slang-wasm/slang-wasm.cpp')

diff --git a/source/slang-wasm/slang-wasm.cpp b/source/slang-wasm/slang-wasm.cpp
new file mode 100644
index 000000000..c2cbe66b6
--- /dev/null
+++ b/source/slang-wasm/slang-wasm.cpp
@@ -0,0 +1,182 @@
+#include <vector>
+#include <string>
+#include <slang.h>
+#include <slang-com-ptr.h>
+#include "slang-wasm.h"
+#include "../core/slang-blob.h"
+#include "../core/slang-exception.h"
+
+using namespace slang;
+
+namespace slang
+{
+namespace wgsl
+{
+
+Error g_error;
+
+Error getLastError()
+{
+    Error currentError = g_error;
+    g_error = {};
+    return currentError;
+}
+
+GlobalSession* createGlobalSession()
+{
+    IGlobalSession* globalSession = nullptr;
+    {
+        SlangResult result = slang::createGlobalSession(&globalSession);
+        if (result != SLANG_OK)
+        {
+            g_error.type = std::string("USER");
+            g_error.result = result;
+            return nullptr;
+        }
+    }
+
+    return new GlobalSession(globalSession);
+}
+
+Session* GlobalSession::createSession()
+{
+    ISession* session = nullptr;
+    {
+        SessionDesc sessionDesc = {};
+        sessionDesc.structureSize = sizeof(sessionDesc);
+        constexpr SlangInt targetCount = 1;
+        TargetDesc targets[targetCount] = {
+            {.structureSize = sizeof(TargetDesc), .format = SLANG_WGSL}
+        };
+        sessionDesc.targets = targets;
+        sessionDesc.targetCount = targetCount;
+        SlangResult result = m_interface->createSession(sessionDesc, &session);
+        if (result != SLANG_OK)
+        {
+            g_error.type = std::string("USER");
+            g_error.result = result;
+            return nullptr;
+        }
+    }
+
+    return new Session(session);
+}
+
+Module* Session::loadModuleFromSource(const std::string& slangCode)
+{
+    Slang::ComPtr<IModule> module;
+    {
+        const char * name = "";
+        const char * path = "";
+        Slang::ComPtr<slang::IBlob> diagnosticsBlob;
+        Slang::ComPtr<ISlangBlob> slangCodeBlob = Slang::RawBlob::create(
+            slangCode.c_str(), slangCode.size());
+        module = m_interface->loadModuleFromSource(
+            name, path, slangCodeBlob, diagnosticsBlob.writeRef());
+        if (!module)
+        {
+            g_error.type = std::string("USER");
+            g_error.message = std::string(
+                (char*)diagnosticsBlob->getBufferPointer(),
+                (char*)diagnosticsBlob->getBufferPointer() +
+                diagnosticsBlob->getBufferSize());
+            return nullptr;
+        }
+    }
+
+    return new Module(module);
+}
+
+EntryPoint* Module::findEntryPointByName(const std::string& name)
+{
+    Slang::ComPtr<IEntryPoint> entryPoint;
+    {
+        SlangResult result = moduleInterface()->findEntryPointByName(
+            name.c_str(), entryPoint.writeRef());
+        if (result != SLANG_OK)
+        {
+            g_error.type = std::string("USER");
+            g_error.result = result;
+            return nullptr;
+        }
+    }
+
+    return new EntryPoint(entryPoint);
+}
+
+ComponentType* Session::createCompositeComponentType(
+    const std::vector<ComponentType*>& components)
+{
+    Slang::ComPtr<IComponentType> composite;
+    {
+        std::vector<IComponentType*> nativeComponents(components.size());
+        for (size_t i = 0U; i < components.size(); i++)
+            nativeComponents[i] = components[i]->interface();
+        SlangResult result = m_interface->createCompositeComponentType(
+            nativeComponents.data(),
+            (SlangInt)nativeComponents.size(),
+            composite.writeRef());
+        if (result != SLANG_OK)
+        {
+            g_error.type = std::string("USER");
+            g_error.result = result;
+            return nullptr;
+        }
+    }
+
+    return new ComponentType(composite);
+}
+
+ComponentType* ComponentType::link()
+{
+    Slang::ComPtr<IComponentType> linkedProgram;
+    {
+        Slang::ComPtr<ISlangBlob> diagnosticBlob;
+        SlangResult result = interface()->link(
+            linkedProgram.writeRef(), diagnosticBlob.writeRef());
+        if (result != SLANG_OK)
+        {
+            g_error.type = std::string("USER");
+            g_error.result = result;
+            g_error.message = std::string(
+                (char*)diagnosticBlob->getBufferPointer(),
+                (char*)diagnosticBlob->getBufferPointer() +
+                diagnosticBlob->getBufferSize());
+            return nullptr;
+        }
+    }
+
+    return new ComponentType(linkedProgram);
+}
+
+std::string ComponentType::getEntryPointCode(int entryPointIndex, int targetIndex)
+{
+    {
+        Slang::ComPtr<IBlob> kernelBlob;
+        Slang::ComPtr<ISlangBlob> diagnosticBlob;
+        SlangResult result = interface()->getEntryPointCode(
+            entryPointIndex,
+            targetIndex,
+            kernelBlob.writeRef(),
+            diagnosticBlob.writeRef());
+        if (result != SLANG_OK)
+        {
+            g_error.type = std::string("USER");
+            g_error.result = result;
+            g_error.message = std::string(
+                (char*)diagnosticBlob->getBufferPointer(),
+                (char*)diagnosticBlob->getBufferPointer() +
+                diagnosticBlob->getBufferSize());
+            return "";
+        }
+        std::string wgslCode = std::string(
+            (char*)kernelBlob->getBufferPointer(),
+            (char*)kernelBlob->getBufferPointer() + kernelBlob->getBufferSize());
+        return wgslCode;
+    }
+
+    return {};
+}
+
+} // namespace wgsl
+} // namespace slang
-- 
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