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

mkeshavaNV · mkeshavaNV · commit d0ae2fb36146 · 2025-03-11T15:29:29.000+05:30
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 shader-slang#6513
diff --git a/source/compiler-core/slang-downstream-compiler.h b/source/compiler-core/slang-downstream-compiler.h
@@ -340,6 +340,9 @@ class IDownstreamCompiler : public ICastable
     /// 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 +401,15 @@ class DownstreamCompilerBase : public ComBaseObject, public IDownstreamCompiler
         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
@@ -49,6 +49,8 @@ class GlslangDownstreamCompiler : public DownstreamCompilerBase
     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 +73,7 @@ class GlslangDownstreamCompiler : public DownstreamCompilerBase
     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 +89,8 @@ 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 +321,25 @@ 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
@@ -184,36 +184,61 @@ 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)
+_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)
     {
         spvDiagnosticPrint(diagnostic);
         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
@@ -166,5 +166,6 @@ 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/slang-ir.cpp b/source/slang/slang-ir.cpp
@@ -7166,6 +7166,75 @@ static void dumpInstExpr(IRDumpContext* context, IRInst* inst)
         }
     }
 
+    // Special case EmbeddedDownstreamIR to show SPIR-V disassembly
+    if (op == kIROp_EmbeddedDownstreamIR)
+    {
+        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, "<invalid SPIR-V>");
+            }
+        }
+        else
+        {
+            dump(context, "<binary blob>");
+        }
+        dump(context, ")");
+        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
@@ -3747,6 +3747,18 @@ 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);
+                }
             }
         }
     }
diff --git a/tests/library/export-library-generics.slang b/tests/library/export-library-generics.slang
@@ -1,4 +1,6 @@
-//TEST_IGNORE_FILE:
+// This test checks the SPIR-V output when compiling a library containing generics with embedded downstream IR.
+
+//TEST:SIMPLE(filecheck=CHECK): -o tests/library/export-library-generics-test.slang-module -target spirv -embed-downstream-ir -profile lib_6_6 -incomplete-library -dump-ir -verbose-paths
 
 // export-library-generics.slang
 
@@ -37,3 +39,10 @@ public int normalFunc(int a, float b)
 {
     return a - floor(b);
 }
+
+// CHECK:[availableInDownstreamIR(6 : Int)]
+// CHECK:EmbeddedDownstreamIR(6 : Int,
+// CHECK:               OpCapability Linkage
+// CHECK:OpDecorate %SLANG_ParameterGroup_Constants__init LinkageAttributes "_SR29export_2Dxlibrary_2Dxgenerics30SLANG_ParameterGroup_ConstantsR8_24xinitp2pi_fi_f" Export
+// CHECK:               OpDecorate %MyType_myMethod LinkageAttributes "_SR29export_2Dxlibrary_2Dxgenerics6MyType8myMethodp1pi_ii" Export
+// CHECK:               OpDecorate %normalFuncUsesGeneric LinkageAttributes "_SR29export_2Dxlibrary_2Dxgenerics21normalFuncUsesGenericp1pi_ii" Export

Original file line number	Diff line number	Diff line change
`@@ -3747,6 +3747,18 @@ SlangResult EndToEndCompileRequest::executeActionsInner()`
`3747`	`3747`	`{`
`3748`	`3748`	`SLANG_RETURN_ON_FAIL(`
`3749`	`3749`	`translationUnit->getModule()->precompileForTarget(targetEnum, nullptr));`
	`3750`	`+`
	`3751`	`+ if (frontEndReq->optionSet.shouldDumpIR())`
	`3752`	`+ {`
	`3753`	`+ DiagnosticSinkWriter writer(frontEndReq->getSink());`
	`3754`	`+`
	`3755`	`+ dumpIR(`
	`3756`	`+ translationUnit->getModule()->getIRModule(),`
	`3757`	`+ frontEndReq->m_irDumpOptions,`
	`3758`	`+ "PRECOMPILE_FOR_TARGET_COMPLETE_ALL",`
	`3759`	`+ frontEndReq->getSourceManager(),`
	`3760`	`+ &writer);`
	`3761`	`+ }`
`3750`	`3762`	`}`
`3751`	`3763`	`}`
`3752`	`3764`	`}`