PR for llvm/llvm-project#79339 #79357
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…on-SHF_ALLOC sections (llvm#79238) A SHN_ABS symbol has never been considered for InputSection::relocateNonAlloc. Before llvm#74686, the code did made it work in the absence of `-z dead-reloc-in-nonalloc=`. There is now a report about such SHN_ABS uses (llvm#74686 (comment)) and I think it makes sense for non-SHF_ALLOC to support SHN_ABS, like SHF_ALLOC sections do. ``` // clang -g __attribute__((weak)) int symbol; int *foo() { return &symbol; } 0x00000023: DW_TAG_variable [2] (0x0000000c) ... DW_AT_location [DW_FORM_exprloc] (DW_OP_addrx 0x0) ``` .debug_addr references `symbol`, which can be redefined by a symbol assignment or --defsym to become a SHN_ABS symbol. The problem is that `!sym.getOutputSection()` cannot discern SHN_ABS from a symbol whose section has been discarded. Since commit 1981b1b, a symbol relative to a discarded section is changed to `Undefined`, so the `SHN_ABS` check become trivial. We currently apply tombstone for a relocation referencing `SharedSymbol`. This patch does not change the behavior. (cherry picked from commit 8abf8d1)
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@smithp35 What do you think about merging this PR to the release branch? |
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This is good to go for merging, a simple safe change. |
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Merged: 0991d3c |
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resolves #79339