lld/test/ELF/arm-exidx-gc.s

   1 // REQUIRES: arm
   2 // RUN: llvm-mc -filetype=obj --arm-add-build-attributes -triple=armv7a-none-linux-gnueabi %s -o %t
   3 // RUN: ld.lld %t --no-merge-exidx-entries -o %t2 --gc-sections
   4 // RUN: llvm-objdump -d --triple=armv7a-none-linux-gnueabi --no-show-raw-insn %t2 | FileCheck %s
   5 // RUN: llvm-objdump -s --triple=armv7a-none-linux-gnueabi %t2 | FileCheck --check-prefix=CHECK-EXIDX %s
   6
   7 /// Test the behavior of .ARM.exidx sections under garbage collection
   8 /// A .ARM.exidx section is live if it has a relocation to a live executable
   9 /// section.
  10 /// A .ARM.exidx section may have a relocation to a .ARM.extab section, if the
  11 /// .ARM.exidx is live then the .ARM.extab section is live
  12
  13  .syntax unified
  14  .section .text.func1, "ax",%progbits
  15  .global func1
  16 func1:
  17  .fnstart
  18  bx lr
  19  .save {r7, lr}
  20  .setfp r7, sp, #0
  21  .fnend
  22
  23  .section .text.unusedfunc1, "ax",%progbits
  24  .global unusedfunc1
  25 unusedfunc1:
  26  .fnstart
  27  bx lr
  28  .cantunwind
  29  .fnend
  30
  31  /// Unwinding instructions for .text2 too large for an inline entry ARM.exidx
  32  /// entry. A separate .ARM.extab section is created to hold the unwind entries
  33  /// The .ARM.exidx table entry has a reference to the .ARM.extab section.
  34  .section .text.func2, "ax",%progbits
  35  .global func2
  36 func2:
  37  .fnstart
  38  bx lr
  39  .personality __gxx_personality_v0
  40  .handlerdata
  41  .section .text.func2
  42  .fnend
  43
  44  /// An unused function with a reference to a .ARM.extab section. Both should
  45  /// be removed by gc.
  46  .section .text.unusedfunc2, "ax",%progbits
  47  .global unusedfunc2
  48 unusedfunc2:
  49  .fnstart
  50  bx lr
  51  .personality __gxx_personality_v1
  52  .handlerdata
  53  .section .text.unusedfunc2
  54  .fnend
  55
  56  /// Dummy implementation of personality routines to satisfy reference from
  57  /// exception tables
  58  .section .text.__gcc_personality_v0, "ax", %progbits
  59  .global __gxx_personality_v0
  60 __gxx_personality_v0:
  61  .fnstart
  62  bx lr
  63  .cantunwind
  64  .fnend
  65
  66  .section .text.__gcc_personality_v1, "ax", %progbits
  67  .global __gxx_personality_v1
  68 __gxx_personality_v1:
  69  .fnstart
  70  bx lr
  71  .cantunwind
  72  .fnend
  73
  74  .section .text.__aeabi_unwind_cpp_pr0, "ax", %progbits
  75  .global __aeabi_unwind_cpp_pr0
  76 __aeabi_unwind_cpp_pr0:
  77  .fnstart
  78  bx lr
  79  .cantunwind
  80  .fnend
  81
  82 // Entry point for GC
  83  .text
  84  .global _start
  85 _start:
  86  bl func1
  87  bl func2
  88  bx lr
  89
  90 /// GC should have only removed unusedfunc1 and unusedfunc2 the personality
  91 /// routines are kept alive by references from live .ARM.exidx and .ARM.extab
  92 /// sections
  93 // CHECK: Disassembly of section .text:
  94 // CHECK-EMPTY:
  95 // CHECK-NEXT: <_start>:
  96 // CHECK-NEXT:   2010c:       bl      0x20118 <func1>
  97 // CHECK-NEXT:   20110:       bl      0x2011c <func2>
  98 // CHECK-NEXT:   20114:       bx      lr
  99 // CHECK: <func1>:
 100 // CHECK-NEXT:   20118:       bx      lr
 101 // CHECK: <func2>:
 102 // CHECK-NEXT:   2011c:       bx      lr
 103 // CHECK: <__gxx_personality_v0>:
 104 // CHECK-NEXT:   20120:       bx      lr
 105 // CHECK: <__aeabi_unwind_cpp_pr0>:
 106 // CHECK-NEXT:   20124:       bx      lr
 107
 108 /// GC should have removed table entries for unusedfunc1, unusedfunc2
 109 /// and __gxx_personality_v1
 110 // CHECK-NOT: unusedfunc1
 111 // CHECK-NOT: unusedfunc2
 112 // CHECK-NOT: __gxx_personality_v1
 113
 114 /// CHECK-EXIDX: Contents of section .ARM.exidx:
 115 /// 100d4 + 1038 = 1110c = _start
 116 /// 100dc + 103c = 11118 = func1
 117 // CHECK-EXIDX-NEXT: 100d4 38000100 01000000 3c000100 08849780
 118 /// 100e4 + 1038 = 1111c = func2 (100e8 + 1c = 10104 = .ARM.extab)
 119 /// 100ec + 1034 = 11120 = __gxx_personality_v0
 120 // CHECK-EXIDX-NEXT: 100e4 38000100 1c000000 34000100 01000000
 121 /// 100f4 + 1030 = 11018 = __aeabi_unwind_cpp_pr0
 122 /// 100fc + 102c = 1101c = __aeabi_unwind_cpp_pr0 + sizeof(__aeabi_unwind_cpp_pr0)
 123 // CHECK-EXIDX-NEXT: 100f4 30000100 01000000 2c000100 01000000
 124 // CHECK-EXIDX-NEXT: Contents of section .ARM.extab:
 125 /// 10104 + 101c = 11120 = __gxx_personality_v0
 126 // CHECK-EXIDX-NEXT: 10104 1c000100 b0b0b000