DWARFv1 constants in enums, DW_FORM_ref parsing #335
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Merging the base
Merge upstream
sevaa
changed the title
sevaa
changed the title
eliben
reviewed
Oct 9, 2020
| @@ -106,7 +106,7 @@ def parse_from_attribute(self, attr, dwarf_version): | |||
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| @staticmethod | |||
| def _attribute_has_loc_expr(attr, dwarf_version): | |||
| return ((dwarf_version < 4 and attr.form == 'DW_FORM_block1' and | |||
| return ((dwarf_version < 4 and attr.form.startswith('DW_FORM_block') and | |||
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Is this correct?
The existing code seems to be specifically targeting DW_FORM_block1, not the other kinds; why is this changing? What new forms are needed for DWARFv1?
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Saw a location expression of formDW_FORM_block2 in the reference binary. There was no block1 in DWARF1, and no locations sections either.
If this is a dealbreaker, we can leave this one out and I'll monkeypatch.
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This PR seems mostly non-controversial, but general support for DWARF v1 is not planned. |
eliben
approved these changes
Oct 10, 2020
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A customer asked for support for DWARF v1.
Building support for DWARFv1 in
pyelftoolsis probably not a fruitful endeavor, since many assumptions of DWARFv2+ break down in v1 (there is no abbrev table, no CU headers, expression and lineprogram format is different). I've already slapped together a DWARFv1 parser that mimicspyelftoolsand reuses some of its pieces.That said, there are some
DW_TAG_,DW_AT_, andDW_FORM_constants that were deprecated in DWARFv2 but can be seen in the v1 spec, and also in my reference DWARFv1 binary. The enums are otherwise identical (modulo the shift-by-4 thing for attribute codes). I'd rather have those constants right there inpyelftoolsthan patch the dicts on the fly.If there is interest in having pyelftools support DWARFv1, let me know.