Fix DebugTypeFunction

lib/SPIRV/LLVMToSPIRVDbgTran.cpp

@@ -435,6 +435,23 @@ SPIRVType *LLVMToSPIRVDbgTran::getInt32Ty() {
   return Int32T;
 }
 
+SPIRVEntry *LLVMToSPIRVDbgTran::getVoidDebugType() {
+  // Create a proper void debug type instead of DebugInfoNone
+  // This is needed for function return types that are void
+  using namespace SPIRVDebug::Operand::TypeBasic;
+  SPIRVWordVec Ops(OperandCountOCL);
+  Ops[NameIdx] = BM->getString("void")->getId();
+  ConstantInt *Size = getUInt(M, 0); // void has size 0
+  Ops[SizeIdx] = SPIRVWriter->transValue(Size, nullptr)->getId();
+  Ops[EncodingIdx] = SPIRVDebug::Unspecified;
+  if (isNonSemanticDebugInfo()) {
+    transformToConstant(Ops, {EncodingIdx});
+    // Flags value could not be generated by clang or by LLVM environment.
+    Ops.push_back(getDebugInfoNoneId());
+  }
+  return BM->addDebugInfo(SPIRVDebug::TypeBasic, getVoidTy(), Ops);
+}
+
 SPIRVEntry *LLVMToSPIRVDbgTran::getScope(DIScope *S) {
   if (S)
     return transDbgEntry(S);
@@ -906,10 +923,16 @@ LLVMToSPIRVDbgTran::transDbgSubroutineType(const DISubroutineType *FT) {
     // First element of the TypeArray is the type of the return value,
     // followed by types of the function arguments' types.
     // The same order is preserved in SPIRV.
-    for (unsigned I = 0; I < NumElements; ++I)
-      Ops[ReturnTypeIdx + I] = transDbgEntry(Types[I])->getId();
+    for (unsigned I = 0; I < NumElements; ++I) {
+      if (Types[I]) {
+        Ops[ReturnTypeIdx + I] = transDbgEntry(Types[I])->getId();
+      } else {
+        // Handle void type - create a proper void debug type instead of DebugInfoNone
+        Ops[ReturnTypeIdx + I] = getVoidDebugType()->getId();
+      }
+    }
   } else { // void foo();
-    Ops[ReturnTypeIdx] = getVoidTy()->getId();
+    Ops[ReturnTypeIdx] = getVoidDebugType()->getId();
   }
 
   if (isNonSemanticDebugInfo())
@@ -1310,7 +1333,36 @@ SPIRVEntry *LLVMToSPIRVDbgTran::transDbgFunction(const DISubprogram *Func) {
     if (DISubprogram *FuncDecl = Func->getDeclaration())
       Ops.push_back(transDbgEntry(FuncDecl)->getId());
     else {
-      Ops.push_back(getDebugInfoNoneId());
+      // Create a DebugFunctionDeclaration for this function definition
+      // since the Declaration operand must be a DebugFunctionDeclaration result ID
+      SPIRVWordVec DeclOps(SPIRVDebug::Operand::FunctionDeclaration::OperandCount);
+      DeclOps[SPIRVDebug::Operand::FunctionDeclaration::NameIdx] = BM->getString(Func->getName().str())->getId();
+      DeclOps[SPIRVDebug::Operand::FunctionDeclaration::TypeIdx] = transDbgEntry(Func->getType())->getId();
+      DeclOps[SPIRVDebug::Operand::FunctionDeclaration::SourceIdx] = getSource(Func)->getId();
+      DeclOps[SPIRVDebug::Operand::FunctionDeclaration::LineIdx] = Func->getLine();
+      DeclOps[SPIRVDebug::Operand::FunctionDeclaration::ColumnIdx] = 0; // This version of DISubprogram has no column number
+      auto *Scope = Func->getScope();
+      if (Scope && !isa<DIFile>(Scope)) {
+        DeclOps[SPIRVDebug::Operand::FunctionDeclaration::ParentIdx] = getScope(Scope)->getId();
+      } else {
+        if (auto *Unit = Func->getUnit())
+          DeclOps[SPIRVDebug::Operand::FunctionDeclaration::ParentIdx] = SPIRVCUMap[Unit]->getId();
+        else
+          // it might so happen, that DISubprogram is missing Unit parameter
+          DeclOps[SPIRVDebug::Operand::FunctionDeclaration::ParentIdx] = SPIRVCUMap.begin()->second->getId();
+      }
+      DeclOps[SPIRVDebug::Operand::FunctionDeclaration::LinkageNameIdx] = BM->getString(Func->getLinkageName().str())->getId();
+      DeclOps[SPIRVDebug::Operand::FunctionDeclaration::FlagsIdx] = adjustAccessFlags(Scope, transDebugFlags(Func));
+      if (isNonSemanticDebugInfo()) {
+        std::vector<SPIRVWord> ConstIdxs = {SPIRVDebug::Operand::FunctionDeclaration::LineIdx, 
+                                            SPIRVDebug::Operand::FunctionDeclaration::ColumnIdx, 
+                                            SPIRVDebug::Operand::FunctionDeclaration::FlagsIdx};
+        transformToConstant(DeclOps, ConstIdxs);
+      }
+
+      SPIRVEntry *CreatedFuncDecl = BM->addDebugInfo(SPIRVDebug::FunctionDeclaration, getVoidTy(), DeclOps);
+      Ops.push_back(CreatedFuncDecl->getId());
+
       if (BM->getDebugInfoEIS() == SPIRVEIS_NonSemantic_Shader_DebugInfo_200) {
         // Translate targetFuncName mostly for Fortran trampoline function if it
         // is the case

lib/SPIRV/LLVMToSPIRVDbgTran.h

@@ -88,6 +88,7 @@ class LLVMToSPIRVDbgTran {
   // Helper methods
   SPIRVType *getVoidTy();
   SPIRVType *getInt32Ty();
+  SPIRVEntry *getVoidDebugType();
   SPIRVEntry *getScope(DIScope *SR);
   SPIRVEntry *getGlobalVariable(const DIGlobalVariable *GV);
   inline bool isNonSemanticDebugInfo();

test/DebugInfo/DebugFunctionDeclarationBug.cl

@@ -0,0 +1,21 @@
+// Test case to verify the fix for the issue where DebugFunction uses DebugInfoNone instead of DebugFunctionDeclaration
+// for the Declaration operand when there's no separate function declaration.
+// This test verifies that spirv-val now passes successfully after the fix.
+
+// RUN: %clang_cc1 %s -emit-llvm-bc -triple spir -debug-info-kind=limited -O0 -o - | llvm-spirv -o %t.spv
+// RUN: spirv-val %t.spv
+
+// This test should pass spirv-val validation after the bug fix
+// We can also verify that the SPIR-V contains proper DebugFunctionDeclaration
+// RUN: llvm-spirv --to-text %t.spv -o - | FileCheck %s --check-prefix=CHECK-SPIRV-TEXT
+
+// CHECK-SPIRV-TEXT: DebugFunctionDeclaration
+// CHECK-SPIRV-TEXT: DebugFunction
+
+int test_function(int x) {
+    return x + 1;
+}
+
+void kernel test_kernel() {
+    int result = test_function(42);
+}