IR: Add SPIR-V disassembly for embedded downstream IR dumps (#6529)

* IR: Add SPIR-V disassembly for embedded downstream IR dumps

When dumping IR that contains embedded downstream SPIR-V code (via
EmbeddedDownstreamIR instructions), display the disassembled SPIR-V
instead of just showing "<binary blob>".

This CL also does:
- Adds a new interface for disassembly and get result.
- Modify export-library-generics.slang test test to check for the
  disassembled SPIR-V

Fixes #6513

* Add module-dual-target-verify test

Fixes #6517
Adds a new test to verify that dxil and spirv targets are stored
separately in the precompiled blob.

* Fix review comments from cheneym2

* format code

---------

Co-authored-by: slangbot <186143334+slangbot@users.noreply.github.com>

7 files changed, 187 insertions, 8 deletions

diff --git a/source/compiler-core/slang-downstream-compiler.h b/source/compiler-core/slang-downstream-compiler.h
index c96003cc4..5365b9839 100644
--- a/source/compiler-core/slang-downstream-compiler.h
+++ b/source/compiler-core/slang-downstream-compiler.h
@@ -340,6 +340,9 @@ public:
     /// Disassemble and print to stdout
     virtual SLANG_NO_THROW SlangResult SLANG_MCALL
     disassemble(const uint32_t* contents, int contentsSize) = 0;
+    /// Disassemble and return the result as a string
+    virtual SLANG_NO_THROW SlangResult SLANG_MCALL
+    disassembleWithResult(const uint32_t* contents, int contentsSize, String& outString) = 0;
 
     /// True if underlying compiler uses file system to communicate source
     virtual SLANG_NO_THROW bool SLANG_MCALL isFileBased() = 0;
@@ -398,6 +401,17 @@ public:
         return SLANG_FAIL;
     }
 
+    virtual SLANG_NO_THROW SlangResult SLANG_MCALL disassembleWithResult(
+        const uint32_t* contents,
+        int contentsSize,
+        String& outString) SLANG_OVERRIDE
+    {
+        SLANG_UNUSED(contents);
+        SLANG_UNUSED(contentsSize);
+        SLANG_UNUSED(outString);
+        return SLANG_FAIL;
+    }
+
     DownstreamCompilerBase(const Desc& desc)
         : m_desc(desc)
     {
diff --git a/source/compiler-core/slang-glslang-compiler.cpp b/source/compiler-core/slang-glslang-compiler.cpp
index 540b437c5..27a24512d 100644
--- a/source/compiler-core/slang-glslang-compiler.cpp
+++ b/source/compiler-core/slang-glslang-compiler.cpp
@@ -49,6 +49,10 @@ public:
     validate(const uint32_t* contents, int contentsSize) SLANG_OVERRIDE;
     virtual SLANG_NO_THROW SlangResult SLANG_MCALL
     disassemble(const uint32_t* contents, int contentsSize) SLANG_OVERRIDE;
+    virtual SLANG_NO_THROW SlangResult SLANG_MCALL disassembleWithResult(
+        const uint32_t* contents,
+        int contentsSize,
+        String& outString) SLANG_OVERRIDE;
     int link(
         const uint32_t** modules,
         const uint32_t* moduleSizes,
@@ -71,6 +75,7 @@ protected:
     glslang_CompileFunc_1_2 m_compile_1_2 = nullptr;
     glslang_ValidateSPIRVFunc m_validate = nullptr;
     glslang_DisassembleSPIRVFunc m_disassemble = nullptr;
+    glslang_DisassembleSPIRVWithResultFunc m_disassembleWithResult = nullptr;
     glslang_LinkSPIRVFunc m_link = nullptr;
 
     ComPtr<ISlangSharedLibrary> m_sharedLibrary;
@@ -86,6 +91,8 @@ SlangResult GlslangDownstreamCompiler::init(ISlangSharedLibrary* library)
     m_validate = (glslang_ValidateSPIRVFunc)library->findFuncByName("glslang_validateSPIRV");
     m_disassemble =
         (glslang_DisassembleSPIRVFunc)library->findFuncByName("glslang_disassembleSPIRV");
+    m_disassembleWithResult = (glslang_DisassembleSPIRVWithResultFunc)library->findFuncByName(
+        "glslang_disassembleSPIRVWithResult");
     m_link = (glslang_LinkSPIRVFunc)library->findFuncByName("glslang_linkSPIRV");
 
     if (m_compile_1_0 == nullptr && m_compile_1_1 == nullptr && m_compile_1_2 == nullptr)
@@ -316,6 +323,28 @@ SlangResult GlslangDownstreamCompiler::validate(const uint32_t* contents, int co
     return SLANG_FAIL;
 }
 
+SlangResult GlslangDownstreamCompiler::disassembleWithResult(
+    const uint32_t* contents,
+    int contentsSize,
+    String& outString)
+{
+    if (m_disassembleWithResult == nullptr)
+    {
+        return SLANG_FAIL;
+    }
+
+    char* resultString = nullptr;
+    if (m_disassembleWithResult(contents, contentsSize, &resultString))
+    {
+        if (resultString)
+        {
+            outString = String(resultString);
+            return SLANG_OK;
+        }
+    }
+    return SLANG_FAIL;
+}
+
 SlangResult GlslangDownstreamCompiler::disassemble(const uint32_t* contents, int contentsSize)
 {
     if (m_disassemble == nullptr)
diff --git a/source/slang-glslang/slang-glslang.cpp b/source/slang-glslang/slang-glslang.cpp
index 3dc9b1bd4..8d9f64fd5 100644
--- a/source/slang-glslang/slang-glslang.cpp
+++ b/source/slang-glslang/slang-glslang.cpp
@@ -184,27 +184,30 @@ extern "C"
     return tools.Validate(contents, contentsSize, options);
 }
 
-// Disassemble the given SPIRV-ASM instructions.
+// Disassemble the given SPIRV-ASM instructions and return the result as a string.
 extern "C"
 #ifdef _MSC_VER
     _declspec(dllexport)
 #else
-    __attribute__((__visibility__("default")))
+__attribute__((__visibility__("default")))
 #endif
-        bool glslang_disassembleSPIRV(const uint32_t* contents, int contentsSize)
+        bool glslang_disassembleSPIRVWithResult(
+            const uint32_t* contents,
+            int contentsSize,
+            char** outString)
 {
     static const auto kDefaultEnvironment = SPV_ENV_UNIVERSAL_1_5;
+    spv_text text;
 
     uint32_t options = SPV_BINARY_TO_TEXT_OPTION_NONE;
     options |= SPV_BINARY_TO_TEXT_OPTION_COMMENT;
-    options |= SPV_BINARY_TO_TEXT_OPTION_PRINT;
-    options |= SPV_BINARY_TO_TEXT_OPTION_COLOR;
     options |= SPV_BINARY_TO_TEXT_OPTION_FRIENDLY_NAMES;
+    options |= SPV_BINARY_TO_TEXT_OPTION_INDENT;
 
     spv_diagnostic diagnostic = nullptr;
     spv_context context = spvContextCreate(kDefaultEnvironment);
     spv_result_t error =
-        spvBinaryToText(context, contents, contentsSize, options, nullptr, &diagnostic);
+        spvBinaryToText(context, contents, contentsSize, options, &text, &diagnostic);
     spvContextDestroy(context);
     if (error)
     {
@@ -212,8 +215,33 @@ extern "C"
         spvDiagnosticDestroy(diagnostic);
         return false;
     }
+    else
+    {
+        if (outString)
+        {
+            // Allocate memory for the output string and copy the result
+            size_t len = text->length + 1; // +1 for null terminator
+            *outString = new char[len];
+            memcpy(*outString, text->str, text->length);
+            (*outString)[text->length] = '\0'; // Ensure null termination
+        }
+
+        spvTextDestroy(text);
+        return true;
+    }
+}
+
 
-    return true;
+// Disassemble the given SPIRV-ASM instructions.
+extern "C"
+#ifdef _MSC_VER
+    _declspec(dllexport)
+#else
+__attribute__((__visibility__("default")))
+#endif
+        bool glslang_disassembleSPIRV(const uint32_t* contents, int contentsSize)
+{
+    return glslang_disassembleSPIRVWithResult(contents, contentsSize, nullptr);
 }
 
 // Apply the SPIRV-Tools optimizer to generated SPIR-V based on the desired optimization level
diff --git a/source/slang-glslang/slang-glslang.h b/source/slang-glslang/slang-glslang.h
index 8343b4c8e..d6e10d320 100644
--- a/source/slang-glslang/slang-glslang.h
+++ b/source/slang-glslang/slang-glslang.h
@@ -166,5 +166,9 @@ typedef int (*glslang_CompileFunc_1_1)(glslang_CompileRequest_1_1* request);
 typedef int (*glslang_CompileFunc_1_2)(glslang_CompileRequest_1_2* request);
 typedef bool (*glslang_ValidateSPIRVFunc)(const uint32_t* contents, int contentsSize);
 typedef bool (*glslang_DisassembleSPIRVFunc)(const uint32_t* contents, int contentsSize);
+typedef bool (*glslang_DisassembleSPIRVWithResultFunc)(
+    const uint32_t* contents,
+    int contentsSize,
+    char** outString);
 typedef bool (*glslang_LinkSPIRVFunc)(glslang_LinkRequest* request);
 #endif
diff --git a/source/slang-llvm/slang-llvm.cpp b/source/slang-llvm/slang-llvm.cpp
index 86565a485..e645fb3c7 100644
--- a/source/slang-llvm/slang-llvm.cpp
+++ b/source/slang-llvm/slang-llvm.cpp
@@ -1,4 +1,3 @@
-
 #include "clang/Basic/Stack.h"
 #include "clang/Basic/TargetOptions.h"
 #include "clang/Basic/Version.h"
@@ -147,6 +146,16 @@ public:
         SLANG_UNUSED(contentsSize);
         return SLANG_FAIL;
     }
+    virtual SLANG_NO_THROW SlangResult SLANG_MCALL disassembleWithResult(
+        const uint32_t* contents,
+        int contentsSize,
+        String& outString) SLANG_OVERRIDE
+    {
+        SLANG_UNUSED(contents);
+        SLANG_UNUSED(contentsSize);
+        SLANG_UNUSED(outString);
+        return SLANG_FAIL;
+    }
 
     LLVMDownstreamCompiler()
         : m_desc(
diff --git a/source/slang/slang-ir.cpp b/source/slang/slang-ir.cpp
index 72313217b..92e51fe3b 100644
--- a/source/slang/slang-ir.cpp
+++ b/source/slang/slang-ir.cpp
@@ -7117,6 +7117,76 @@ void dumpIRGeneric(IRDumpContext* context, IRGeneric* witnessTable)
     dump(context, "}\n");
 }
 
+static void dumpEmbeddedDownstream(IRDumpContext* context, IRInst* inst)
+{
+    auto targetInst = inst->getOperand(0);
+    auto blobInst = inst->getOperand(1);
+
+    // Get the target value
+    auto targetLit = as<IRIntLit>(targetInst);
+    if (!targetLit)
+    {
+        dump(context, "EmbeddedDownstreamIR(invalid target)");
+        return;
+    }
+
+    // Get the blob
+    auto blobLitInst = as<IRBlobLit>(blobInst);
+    if (!blobLitInst)
+    {
+        dump(context, "EmbeddedDownstreamIR(invalid blob)");
+        return;
+    }
+
+    dump(context, "EmbeddedDownstreamIR(");
+    dump(context, targetLit->getValue());
+    dump(context, " : Int, ");
+
+    // If target is SPIR-V (6), disassemble the blob
+    if (targetLit->getValue() == (IRIntegerValue)CodeGenTarget::SPIRV)
+    {
+        auto blob = blobLitInst->getStringSlice();
+        const uint32_t* spirvCode = (const uint32_t*)blob.begin();
+        const size_t spirvWordCount = blob.getLength() / sizeof(uint32_t);
+
+        // Get the compiler from the session through the module
+        auto module = inst->getModule();
+        auto session = module->getSession();
+        IDownstreamCompiler* compiler =
+            session->getOrLoadDownstreamCompiler(PassThroughMode::SpirvDis, nullptr);
+
+        if (compiler)
+        {
+            // Use glslang interface to disassemble with string output
+            String disassemblyOutput;
+            if (SLANG_SUCCEEDED(compiler->disassembleWithResult(
+                    spirvCode,
+                    int(spirvWordCount),
+                    disassemblyOutput)))
+            {
+                // Dump the captured disassembly
+                dump(context, "\n");
+                dumpIndent(context);
+                dump(context, disassemblyOutput);
+            }
+            else
+            {
+                dump(context, "<disassembly failed>");
+            }
+        }
+        else
+        {
+            dump(context, "<unavailable disassembler>");
+        }
+    }
+    else
+    {
+        // TODO: Add DXIL disassembly call here.
+        dump(context, "<binary blob>");
+    }
+    dump(context, ")");
+}
+
 static void dumpInstExpr(IRDumpContext* context, IRInst* inst)
 {
     if (!inst)
@@ -7166,6 +7236,13 @@ static void dumpInstExpr(IRDumpContext* context, IRInst* inst)
         }
     }
 
+    // Special case EmbeddedDownstreamIR to show SPIR-V disassembly
+    if (op == kIROp_EmbeddedDownstreamIR)
+    {
+        dumpEmbeddedDownstream(context, inst);
+        return;
+    }
+
     // Special case the SPIR-V asm operands as the distinction here is
     // clear anyway to the user
     switch (op)
diff --git a/source/slang/slang.cpp b/source/slang/slang.cpp
index e17d7ba9c..a23342458 100644
--- a/source/slang/slang.cpp
+++ b/source/slang/slang.cpp
@@ -3747,6 +3747,24 @@ SlangResult EndToEndCompileRequest::executeActionsInner()
             {
                 SLANG_RETURN_ON_FAIL(
                     translationUnit->getModule()->precompileForTarget(targetEnum, nullptr));
+
+                if (frontEndReq->optionSet.shouldDumpIR())
+                {
+                    DiagnosticSinkWriter writer(frontEndReq->getSink());
+
+                    dumpIR(
+                        translationUnit->getModule()->getIRModule(),
+                        frontEndReq->m_irDumpOptions,
+                        "PRECOMPILE_FOR_TARGET_COMPLETE_ALL",
+                        frontEndReq->getSourceManager(),
+                        &writer);
+
+                    dumpIR(
+                        translationUnit->getModule()->getIRModule()->getModuleInst(),
+                        frontEndReq->m_irDumpOptions,
+                        frontEndReq->getSourceManager(),
+                        &writer);
+                }
             }
         }
     }