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

[David Spickett via lldb-commits]

================
@@ -188,7 +188,74 @@ 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();
----------------
DavidSpickett wrote:

But later you say:
```
if (sectionNumber > 0 
```
and it's a signed int, so it could be negative.

So if it can be 0, then sectionIndex could become 0xffffffffffffffff. Now maybe it doesn't get used in that scenario but if it did, it would not do good things.

I would move the `if sectionNumber > 0` up to before you calculate the section index. Then you aren't creating random sectionIndex values. 

Plus, it should be clearer then what range of values we expect from sectionNumber.

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