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

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<!--LLVM PR SUMMARY COMMENT-->

@llvm/pr-subscribers-lldb

Author: Dhruv Srivastava (DhruvSrivastavaX)

<details>
<summary>Changes</summary>

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.

---
Full diff: https://github.com/llvm/llvm-project/pull/141577.diff


1 Files Affected:

- (modified) lldb/source/Plugins/ObjectFile/XCOFF/ObjectFileXCOFF.cpp (+65-1) 


``````````diff
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; }
 

``````````

</details>


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