lld/test/MachO/icf-only-lsda-folded.s

   1 # REQUIRES: x86
   2 # RUN: rm -rf %t; split-file %s %t
   3
   4 ## This is a regression test. Previously, we would emit a bogus LSDA pointer if
   5 ## the following conditions held:
   6 ##   * ICF and dead-strip were both done
   7 ##   * There exist two functions different compact unwind encodings, but the
   8 ##     same LSDA
   9 ##
  10 ## Essentially, we'd neglected to canonicalize the LSDA pointer after ICF, but
  11 ## the broken output would only appear if the compact unwind entry that pointed
  12 ## to it was not itself folded.
  13
  14 # RUN: llvm-mc -emit-compact-unwind-non-canonical=true -filetype=obj -triple=x86_64-apple-darwin19.0.0 %t/test.s -o %t/test.o
  15 # RUN: %lld -dylib -dead_strip --icf=all %t/test.o -o %t/test
  16 # RUN: llvm-objdump --macho --syms --unwind-info %t/test | FileCheck %s
  17
  18 # CHECK:      SYMBOL TABLE:
  19 ## Sanity check: Verify that the LSDAs are dedup'ed
  20 # CHECK-NEXT: [[#%.16x, EXC:]]       l     O __TEXT,__gcc_except_tab _exception0
  21 # CHECK-NEXT: [[#EXC]]               l     O __TEXT,__gcc_except_tab _exception1
  22 ## But that the functions themselves aren't
  23 # CHECK-NEXT: [[#%.16x, FOO:]]        g     F __TEXT,__text _foo
  24 # CHECK-NEXT: [[#%.16x, BAR:FOO + 1]] g     F __TEXT,__text _bar
  25
  26 ## _foo and _bar should share the same LSDA. We would previously emit a bogus
  27 ## address for _bar's LSDA.
  28 # CHECK:      Contents of __unwind_info section:
  29 # CHECK:      LSDA descriptors:
  30 # CHECK-NEXT:     [0]: function offset=0x[[#%.8x, FOO]], LSDA offset=0x[[#%.8x, EXC]]
  31 # CHECK-NEXT:     [1]: function offset=0x[[#%.8x, BAR]], LSDA offset=0x[[#%.8x, EXC]]
  32
  33 ## But there should be two distinct encodings, one for each function
  34 # CHECK:      Second level indices:
  35 # CHECK-NEXT:     Second level index[0]:
  36 # CHECK-NEXT:       [0]: function offset=0x[[#%.8x, FOO]], encoding[0]=0x42020000
  37 # CHECK-NEXT:       [1]: function offset=0x[[#%.8x, BAR]], encoding[1]=0x42010000
  38
  39 #--- test.s
  40 .text
  41 .globl _foo, _bar
  42
  43 _foo:
  44   .cfi_startproc
  45         .cfi_lsda 16, _exception0
  46         .cfi_def_cfa_offset 16
  47   ret
  48   .cfi_endproc
  49
  50 _bar:
  51   .cfi_startproc
  52         .cfi_lsda 16, _exception1
  53         .cfi_def_cfa_offset 8 ## ensure _bar's CUE doesn't get folded with _foo's
  54   ret
  55   .cfi_endproc
  56
  57 .section        __TEXT,__gcc_except_tab
  58
  59 _exception0:
  60   .quad 0x1234
  61
  62 _exception1:
  63   .quad 0x1234
  64
  65 .subsections_via_symbols