lld/test/MachO/arm64-thunk-for-alignment.s

   1 # REQUIRES: aarch64
   2 # RUN: rm -rf %t; split-file %s %t
   3 # RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/foo.s -o %t/foo.o
   4 # RUN: llvm-mc -filetype=obj -triple=arm64-apple-darwin %t/bar.s -o %t/bar.o
   5 # RUN: %lld -dylib -arch arm64 -lSystem -o %t/out %t/foo.o %t/bar.o
   6
   7 # RUN: llvm-objdump --macho --syms %t/out | FileCheck %s
   8 # CHECK: _bar.thunk.0
   9
  10 ## Regression test for PR59259. Previously, we neglected to check section
  11 ## alignments when deciding when to create thunks.
  12
  13 ## If we ignore alignment, the total size of _spacer1 + _spacer2 below is just
  14 ## under the limit at which we attempt to insert thunks between the spacers.
  15 ## However, with alignment accounted for, their total size ends up being
  16 ## 0x8000000, which is just above the max forward branch range, making thunk
  17 ## insertion necessary. Thus, not accounting for alignment led to an error.
  18
  19 #--- foo.s
  20
  21 _foo:
  22   b _bar
  23
  24 ## Size of a `b` instruction.
  25 .equ callSize, 4
  26 ## Refer to `slop` in TextOutputSection::finalize().
  27 .equ slopSize, 12 * 256
  28
  29 _spacer1:
  30   .space 0x4000000 - slopSize - 2 * callSize - 1
  31
  32 .subsections_via_symbols
  33
  34 #--- bar.s
  35 .globl _bar
  36
  37 .p2align 14
  38 _spacer2:
  39   .space 0x4000000
  40
  41 _bar:
  42   ret
  43
  44 .subsections_via_symbols