probinson added a comment. In D71487#1791824 <https://reviews.llvm.org/D71487#1791824>, @clayborg wrote:
> BTW: is used to be that both DW_AT_low_pc and DW_AT_high_pc would be set to > zero when a function was dead stripped. This was back when both the low and > high pc used DW_FORM_addr (a file address). But then DWARF changed such that > DW_AT_high_pc could be encoded as a data form: DW_FORM_data1, DW_FORM_data2, > DW_FORM_data4, or DW_FORM_data8. This is used to mean it is an offset from > the low PC. Seems the linkers now didn't have a relocation for the > DW_AT_high_pc so they couldn't zero it out. This is sad because we can end up > with many functions at address zero that didn't get linked, and if zero is a > valid address, then our DWARF contains a bunch of useless info that only > hides which function is the real function for address zero. One solution, which we do in Sony, is to make the linker fix up undefined references to be -1 instead of 0 (at least, in the .debug_* sections). That's more obviously an invalid address. Doesn't help with existing objects in the wild but I'd like to keep that idea in the air as a forward evolutionary step. Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D71487/new/ https://reviews.llvm.org/D71487 _______________________________________________ lldb-commits mailing list lldb-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/lldb-commits
