[Lldb-commits] [lldb] [lldb][AIX] Added XCOFF ParseSymtab handling (PR #141577)

[Dhruv Srivastava via lldb-commits]

https://github.com/DhruvSrivastavaX created https://github.com/llvm/llvm-project/pull/141577

This PR is in reference to porting LLDB on AIX.

Link to discussions on llvm discourse and github:

1. https://discourse.llvm.org/t/port-lldb-to-ibm-aix/80640
2. https://github.com/llvm/llvm-project/issues/101657
The complete changes for porting are present in this draft PR:
https://github.com/llvm/llvm-project/pull/102601

**Description:**
Adding ParseSymtab logic after creating sections. It is able to handle both 32 and 64 bit symbols, 
without the need to add template logic.

This is an incremental PR on top of my previous couple of XCOFF support commits.

>From a62cd7b510f3cf74ee356a95a26e0f9922f4b39c Mon Sep 17 00:00:00 2001
From: DhruvSrivastavaX <dhruv.srivastava at ibm.com>
Date: Tue, 27 May 2025 05:44:55 -0500
Subject: [PATCH] Added XCOFF ParseSymtab handling

---
 .../ObjectFile/XCOFF/ObjectFileXCOFF.cpp      | 66 ++++++++++++++++++-
 1 file changed, 65 insertions(+), 1 deletion(-)

diff --git a/lldb/source/Plugins/ObjectFile/XCOFF/ObjectFileXCOFF.cpp b/lldb/source/Plugins/ObjectFile/XCOFF/ObjectFileXCOFF.cpp
index e629355cd40b9..7dfe6c362add4 100644
--- a/lldb/source/Plugins/ObjectFile/XCOFF/ObjectFileXCOFF.cpp
+++ b/lldb/source/Plugins/ObjectFile/XCOFF/ObjectFileXCOFF.cpp
@@ -188,7 +188,71 @@ AddressClass ObjectFileXCOFF::GetAddressClass(addr_t file_addr) {
   return AddressClass::eUnknown;
 }
 
-void ObjectFileXCOFF::ParseSymtab(Symtab &lldb_symtab) {}
+lldb::SymbolType MapSymbolType(llvm::object::SymbolRef::Type sym_type) {
+  if (sym_type == llvm::object::SymbolRef::ST_Function)
+    return lldb::eSymbolTypeCode;
+  else if (sym_type == llvm::object::SymbolRef::ST_Data)
+    return lldb::eSymbolTypeData;
+  else if (sym_type == llvm::object::SymbolRef::ST_File)
+    return lldb::eSymbolTypeSourceFile;
+  return lldb::eSymbolTypeInvalid;
+}
+
+void ObjectFileXCOFF::ParseSymtab(Symtab &lldb_symtab) {
+  SectionList *sectionList = GetSectionList();
+
+  for (const auto &symbol_ref : m_binary->symbols()) {
+    llvm::object::XCOFFSymbolRef xcoff_sym_ref(symbol_ref);
+    llvm::Expected<llvm::StringRef> name_or_err = xcoff_sym_ref.getName();
+    if (!name_or_err) {
+      consumeError(name_or_err.takeError());
+      continue;
+    }
+    llvm::StringRef symbolName = name_or_err.get();
+    // Remove the dot prefix for demangle
+    llvm::StringRef symbol_name =
+        symbolName.starts_with(".") ? symbolName.drop_front() : symbolName;
+    auto storageClass = xcoff_sym_ref.getStorageClass();
+    if (storageClass == XCOFF::C_HIDEXT && symbolName != "TOC") {
+      if (xcoff_sym_ref.getNumberOfAuxEntries() != 1)
+        continue;
+      auto aux_csect_or_err = xcoff_sym_ref.getXCOFFCsectAuxRef();
+      if (!aux_csect_or_err) {
+        consumeError(aux_csect_or_err.takeError());
+        continue;
+      }
+      const llvm::object::XCOFFCsectAuxRef csect_aux = aux_csect_or_err.get();
+      if (csect_aux.getStorageMappingClass() != XCOFF::XMC_PR ||
+          (m_binary->is64Bit() ? (csect_aux.getAuxType64() != XCOFF::AUX_CSECT)
+                               : false))
+        continue;
+    }
+
+    Symbol symbol;
+    symbol.GetMangled().SetValue(ConstString(symbol_name));
+
+    int16_t sectionNumber = xcoff_sym_ref.getSectionNumber();
+    size_t sectionIndex = static_cast<size_t>(sectionNumber - 1);
+    if (sectionNumber > 0 && sectionIndex < sectionList->GetSize()) {
+      lldb::SectionSP section_sp =
+          sectionList->GetSectionAtIndex(sectionNumber - 1);
+      if (!section_sp || section_sp->GetFileAddress() == LLDB_INVALID_ADDRESS)
+        continue;
+      lldb::addr_t file_addr = section_sp->GetFileAddress();
+      lldb::addr_t symbolValue = xcoff_sym_ref.getValue();
+      if (symbolValue < file_addr)
+        continue;
+      symbol.GetAddressRef() = Address(section_sp, symbolValue - file_addr);
+    }
+
+    Expected<llvm::object::SymbolRef::Type> sym_type_or_err =
+        symbol_ref.getType();
+    symbol.SetType(MapSymbolType(sym_type_or_err.get()));
+    printf("%s %d\n", symbol.GetName(), *sym_type_or_err);
+
+    lldb_symtab.AddSymbol(symbol);
+  }
+}
 
 bool ObjectFileXCOFF::IsStripped() { return false; }