[PATCH] D72900: [DebugInfo] Support 64-bit DWARF for .debug_names.

[David Blaikie via Phabricator via llvm-commits]

dblaikie added inline comments.


================
Comment at: llvm/lib/DebugInfo/DWARF/DWARFAcceleratorTable.cpp:394-397
   // Check that we can read the fixed-size part.
   if (!AS.isValidOffsetForDataOfSize(*Offset, DWARF32HeaderFixedPartSize))
     return createStringError(errc::illegal_byte_sequence,
                              "Section too small: cannot read header.");
----------------
Perhaps this could be refactored to common the length test?

```
uint64_t StartingOffset = *Offset);
UnitLength = ...;
Format = UnitLength == dwarf::DW_LENGTH_DWARF64 ? dwarf::DWARF64 : dwarf::DWARF32;
if (!AS.isValidOffsetForDataOfSize(StartingOffset, dwarf::getUnitLengthFieldByteSize(Format) + CommonHeaderSize))
  return createStringError(...);
if (Format == dwarf::DWARF64) {
  UnitLength = AS.getU64(Offset);
} else if (...) {
  return createStringError(...);
}
```

I'm not super convinced it's so much better - but it does avoid the quirky "- 4" and such.

Alternatively we could skip all this and use the Error second parameter to the DataExtractor functions, and handle the error after the read attempts? More like the way DWARFUnitHeader::extract works, for example.



CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D72900/new/

https://reviews.llvm.org/D72900