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| author | Fangrui Song <i@maskray.me> | 2022-02-23 10:15:42 -0800 |
|---|---|---|
| committer | Fangrui Song <i@maskray.me> | 2022-02-23 10:15:42 -0800 |
| commit | fc0aa8424ca98da29a9c7aa15b4427d47504ba87 (patch) | |
| tree | d7b839e39899f6f98d2ac1709d37358c4649242e /llvm/lib/CodeGen/MachineOutliner.cpp | |
| parent | b3a778fb5eca0e6032f3d62c03a673c2431be8a0 (diff) | |
| download | llvm-fc0aa8424ca98da29a9c7aa15b4427d47504ba87.zip llvm-fc0aa8424ca98da29a9c7aa15b4427d47504ba87.tar.gz llvm-fc0aa8424ca98da29a9c7aa15b4427d47504ba87.tar.bz2 | |
[ELF] Check COMMON symbols for PROVIDE and don't redefine COMMON symbols edata/end/etext
In GNU ld, the definition precedence is: regular symbol assignment > relocatable object definition > `PROVIDE` symbol assignment.
GNU ld's internal linker scripts define the non-reserved (by C and C++)
edata/end/etext with `PROVIDE` so the relocatable object definition takes
precedence. This makes sense because `int end;` is valid.
We currently redefine such symbols if they are COMMON, but not if they are
regular definitions, so `int end;` with -fcommon is essentially a UB in ld.lld.
Fix this (also improve consistency and match GNU ld) by using the
`isDefined` code path for `isCommon`. In GNU ld, reserved identifiers like
`__ehdr_start` do not use `PROVIDE`, while we treat them all as `PROVIDE`, this
seems fine.
Reviewed By: peter.smith
Differential Revision: https://reviews.llvm.org/D120389
Diffstat (limited to 'llvm/lib/CodeGen/MachineOutliner.cpp')
0 files changed, 0 insertions, 0 deletions