Cleanup how DWARFDie attributes are accessed and decoded.

Removed all DWARFDie::getAttributeValueAs*() calls.
Renamed:
  Optional<DWARFFormValue> DWARFDie::getAttributeValue(dwarf::Attribute);
To:
  Optional<DWARFFormValue> DWARFDie::find(dwarf::Attribute);
Added:
  Optional<DWARFFormValue> DWARFDie::findRecursively(dwarf::Attribute);
  
All decoding of Optional<DWARFFormValue> values are now done using the dwarf::to*() functions from DWARFFormValue.h:

Old code:
  
  auto DeclLine = DWARFDie.getAttributeValueAsSignedConstant(DW_AT_decl_line).getValueOr(0);
  
New code:

  auto DeclLine = toUnsigned(DWARFDie.find(DW_AT_decl_line), 0);
  
This composition helps us since we can now easily do:

  auto DeclLine = toUnsigned(DWARFDie.findRecursively(DW_AT_decl_line), 0);
  
This allows us to easily find attribute values in the current DIE only (the first new code above) or in any DW_AT_abstract_origin or DW_AT_specification Dies using the line above. Note that the code line length is shorter and more concise.

Differential Revision: https://reviews.llvm.org/D28581



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@291959 91177308-0d34-0410-b5e6-96231b3b80d8
9 files changed