[lldb] [llvm] Annotate disassembly with register‐resident variable locations (PR #147460)

[Adrian Prantl via llvm-commits]

================
@@ -702,6 +705,78 @@ void Instruction::Dump(lldb_private::Stream *s, uint32_t max_opcode_byte_size,
   ss.FillLastLineToColumn(opcode_pos + opcode_column_width, ' ');
   ss.PutCString(mnemonics);
 
+  const size_t annotation_column = 150;
+
+  if (exe_ctx && exe_ctx->GetFramePtr()) {
+    StackFrame *frame = exe_ctx->GetFramePtr();
+    TargetSP target_sp = exe_ctx->GetTargetSP();
+    if (frame && target_sp) {
+      addr_t current_pc = m_address.GetLoadAddress(target_sp.get());
+      addr_t original_pc = frame->GetFrameCodeAddress().GetLoadAddress(target_sp.get());
+      if (frame->ChangePC(current_pc)) {
+        VariableListSP var_list_sp = frame->GetInScopeVariableList(true);
+        SymbolContext sc = frame->GetSymbolContext(eSymbolContextFunction);
+        addr_t func_load_addr = LLDB_INVALID_ADDRESS;
+        if (sc.function)
+          func_load_addr = sc.function->GetAddress().GetLoadAddress(target_sp.get());
+
+        
+        if(ss.GetSizeOfLastLine() < annotation_column) {
+
+          std::vector<std::string> annotations;
+
+          if (var_list_sp) {
+            for (size_t i = 0; i < var_list_sp->GetSize(); ++i) {
+              VariableSP var_sp = var_list_sp->GetVariableAtIndex(i);
+              if (!var_sp)
+                continue;
+
+              const char *name = var_sp->GetName().AsCString();
+              auto &expr_list = var_sp->LocationExpressionList();
+              if (!expr_list.IsValid())
+                continue;
+              // Handle std::optional<DWARFExpressionEntry>.
+              if (auto entryOrErr = expr_list.GetExpressionEntryAtAddress(func_load_addr, current_pc)) {
+                auto entry = *entryOrErr;
+
+                // Check if entry has a file_range, and filter on address if so.
+                if (!entry.file_range || entry.file_range->ContainsFileAddress(
+                        (current_pc - func_load_addr) + expr_list.GetFuncFileAddress())) {
+                  
+                  StreamString loc_str;
+                  ABI *abi = exe_ctx->GetProcessPtr()->GetABI().get();
+                  llvm::DIDumpOptions opts;
+                  opts.ShowAddresses = false;
+                  opts.PrintRegisterOnly = true; // <-- important: suppress DW_OP_... annotations, etc.
+
+                  entry.expr->DumpLocationWithOptions(&loc_str, eDescriptionLevelBrief, abi, opts);
+
+                  // Only include if not empty
+                  llvm::StringRef loc_clean = llvm::StringRef(loc_str.GetString()).trim();
+                  if (!loc_clean.empty()) {
+                    annotations.push_back(llvm::formatv("{0} = {1}", name, loc_clean));
+                  }
+                }
+              }
+            }
+
+            if (!annotations.empty()) {
+              ss.FillLastLineToColumn(annotation_column, ' ');
+              ss.PutCString(" ; ");
+              for (size_t i = 0; i < annotations.size(); ++i) {
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adrian-prantl wrote:

- range-based for
- there is also a helper in LLVM to join a list with a separator (https://llvm.org/doxygen/StringExtras_8h_source.html)

https://github.com/llvm/llvm-project/pull/147460