[llvm] [SPIRV] Emit NonSemantic DebugGlobalVariable (PR #207230)

[Manuel Carrasco via llvm-commits]

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@@ -561,6 +586,90 @@ std::optional<MCRegister> SPIRVNonSemanticDebugHandler::mapDISignatureTypeToReg(
   return lookupOptReg(DebugTypeRegs, Ty);
 }
 
+std::optional<MCRegister>
+SPIRVNonSemanticDebugHandler::resolveGlobalVariableParent(
+    const DIGlobalVariable *GV) const {
+  // TODO: When this backend emits debug instructions for namespace, subprogram,
+  // and module scopes, return GV->getScope()'s debug id.
+
+  // Fallback: first module compile unit (SPIRV-LLVM-Translator default).
+  if (CompileUnits.empty())
+    return std::nullopt;
+  return lookupOptReg(CUToCompilationUnitDbgReg, CompileUnits[0].TheCU);
+}
+
+// Unimplemented no-op; see emitDebugExpression declaration.
+std::optional<MCRegister> SPIRVNonSemanticDebugHandler::emitDebugExpression(
+    const DIExpression *, MCRegister, MCRegister, SPIRV::ModuleAnalysisInfo &) {
+  return std::nullopt;
+}
+
+std::optional<MCRegister> SPIRVNonSemanticDebugHandler::emitDebugGlobalVariable(
+    const DIGlobalVariable *GV, MCRegister VoidTypeReg, MCRegister I32TypeReg,
+    MCRegister ExtInstSetReg, SPIRV::ModuleAnalysisInfo &MAI) {
+  assert(GV && "GV must not be null in emitDebugGlobalVariable");
+
+  auto ParentRegOpt = resolveGlobalVariableParent(GV);
+  if (!ParentRegOpt)
+    return std::nullopt;
+
+  // TyReg: DebugInfoNone when GV has no DI type (as done in
+  // SPIRV-LLVM-Translator). Declarations (isDefinition: false) can have null
+  // getType() while definitions must have a non-null one (enforced by the IR
+  // verifier).
+  MCRegister TyReg = CachedDebugInfoNoneReg;
+  if (const DIType *Ty = GV->getType()) {
+    auto TyRegOpt = lookupOptReg(DebugTypeRegs, Ty);
+    if (!TyRegOpt)
+      return std::nullopt;
+    TyReg = *TyRegOpt;
+  }
+
+  std::optional<MCRegister> StaticMemberRegOpt;
+  if (const DIDerivedType *SM = GV->getStaticDataMemberDeclaration()) {
+    StaticMemberRegOpt = lookupOptReg(DebugTypeRegs, SM);
+    if (!StaticMemberRegOpt)
+      return std::nullopt;
+  }
+
+  MCRegister NameReg = getCachedOpStringReg(GV->getName());
+  MCRegister LinkageReg = getCachedOpStringReg(GV->getLinkageName());
+  MCRegister FileStrReg = getCachedOpStringReg(getDebugFullPath(GV->getFile()));
----------------
mgcarrasco wrote:

Done

https://github.com/llvm/llvm-project/pull/207230