[all-commits] [llvm/llvm-project] a14cca: [ELF] Support 128-bit bitmask in oneof(RelExpr)

[Fangrui Song via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a14ccaf5098ae13da22495444aa3b88097387168
      https://github.com/llvm/llvm-project/commit/a14ccaf5098ae13da22495444aa3b88097387168
  Author: Fangrui Song <i at maskray.me>
  Date:   2021-10-25 (Mon, 25 Oct 2021)

  Changed paths:
    M lld/ELF/Relocations.cpp

  Log Message:
  -----------
  [ELF] Support 128-bit bitmask in oneof(RelExpr)

Taken from Chih-Mao Chen's D100835.

RelExpr has 64 bits now and needs the extension to support new members
(`R_PLT_GOTPLT` for `R_X86_64_PLTOFF64` support).

Note: RelExpr needs to have at least a member >=64 to prevent
-Wtautological-constant-out-of-range-compare for `if (expr >= 64)`.

Reviewed By: arichardson, peter.smith

Differential Revision: https://reviews.llvm.org/D112385


  Commit: ca8105b76c1e3790e20fdd460cf1fb66f864020f
      https://github.com/llvm/llvm-project/commit/ca8105b76c1e3790e20fdd460cf1fb66f864020f
  Author: Fangrui Song <i at maskray.me>
  Date:   2021-10-25 (Mon, 25 Oct 2021)

  Changed paths:
    M lld/ELF/Arch/X86_64.cpp
    M lld/ELF/InputSection.cpp
    M lld/ELF/Relocations.cpp
    M lld/ELF/Relocations.h
    A lld/test/ELF/x86-64-reloc-pltoff64.s

  Log Message:
  -----------
  [ELF][X86] Support R_X86_64_PLTOFF64

For a function call (using the default `-fplt`), GCC `-mcmodel=large` generates an assembly modifier which
leads to an R_X86_64_PLTOFF64 relocation. In real world,
http://git.ageinghacker.net/jitter (used by GNU poke) uses `-mcmodel=large`.

R_X86_64_PLTOFF64's formula is (if preemptible) `L - GOT + A` or (if non-preemptible) `S - GOT + A`
where `GOT` is (confusingly) the address of `.got.plt`

Reviewed By: peter.smith

Differential Revision: https://reviews.llvm.org/D112386


Compare: https://github.com/llvm/llvm-project/compare/593814a10cb4...ca8105b76c1e