6afbda7130
As stated in `UnwindInfoSectionImpl::prepareRelocations`'s comments, the unwind info uses section+addend relocations for personality functions defined in the same file as the function itself. As personality functions are always accessed via the GOT, we need to resolve those to a symbol. Previously, we did this by keeping a map which resolves these to symbols, creating a synthetic symbol if we didn't find it in the map. This approach has an issue: if we process the object file containing the personality function before any external uses, the entry in the map remains unpopulated, so we create a synthetic symbol and a corresponding GOT entry. If we encounter a relocation to it in a later file which requires GOT (such as in `__eh_frame`), we add that symbol to the GOT, too, effectively creating two entries which point to the same piece of code. This commit fixes that by searching the personality function's section for a symbol at that offset which already has a GOT entry, and only creating a synthetic symbol if there is none. As all non-unwind sections are already processed by this point, it ensures no duplication. This should only really affect our tests (and make them clearer), as personality functions are usually defined in platform runtime libraries. Or even if they are local, they are likely not in the first object file to be linked.
32 KiB
32 KiB