lld/test/ELF/debug-dead-reloc.s

   1 # REQUIRES: x86
   2 ## Test we resolve symbolic relocations in .debug_* sections to a tombstone
   3 ## value if the referenced symbol is discarded (--gc-sections, non-prevailing
   4 ## section group, SHF_EXCLUDE, /DISCARD/, etc).
   5
   6 # RUN: echo '.globl _start; _start: call group' | llvm-mc -filetype=obj -triple=x86_64 - -o %t.o
   7 # RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t1.o
   8 # RUN: ld.lld --emit-relocs --gc-sections %t.o %t1.o %t1.o -o %t
   9 # RUN: llvm-objdump -s %t | FileCheck %s
  10 # RUN: llvm-readobj -r %t | FileCheck %s --check-prefix=REL
  11
  12 # CHECK:      Contents of section .debug_loc:
  13 # CHECK-NEXT:  0000 01000000 00000000 01000000 00000000
  14 # CHECK:      Contents of section .debug_ranges:
  15 # CHECK-NEXT:  0000 01000000 00000000 01000000 00000000
  16 # CHECK:      Contents of section .debug_addr:
  17 # CHECK-NEXT:  0000 {{.*}}000 00000000 {{.*}}000 00000000
  18 # CHECK-NEXT:  0010 00000000  00000000 {{.*}}000 00000000
  19 # CHECK:      Contents of section .debug_foo:
  20 # CHECK-NEXT:  0000 00000000 00000000 08000000 00000000
  21 # CHECK-NEXT:  0010 00000000 00000000 08000000 00000000
  22
  23 # REL:      Relocations [
  24 # REL-NEXT:   .rela.text {
  25 # REL-NEXT:     0x201121 R_X86_64_PLT32 group 0xFFFFFFFFFFFFFFFC
  26 # REL-NEXT:   }
  27 # REL-NEXT:   .rela.debug_loc {
  28 # REL-NEXT:     0x0 R_X86_64_NONE - 0x8
  29 # REL-NEXT:     0x8 R_X86_64_NONE - 0x8
  30 # REL-NEXT:   }
  31 # REL-NEXT:   .rela.debug_ranges {
  32 # REL-NEXT:     0x0 R_X86_64_NONE - 0x10
  33 # REL-NEXT:     0x8 R_X86_64_NONE - 0x10
  34 # REL-NEXT:   }
  35 # REL-NEXT:   .rela.debug_addr {
  36 # REL-NEXT:     0x0 R_X86_64_64 .text 0x1D
  37 # REL-NEXT:     0x8 R_X86_64_64 group 0x20
  38 # REL-NEXT:     0x10 R_X86_64_NONE - 0x18
  39 # REL-NEXT:     0x18 R_X86_64_64 group 0x20
  40 # REL-NEXT:   }
  41 # REL-NEXT:   .rela.debug_foo {
  42 # REL-NEXT:     0x0 R_X86_64_NONE - 0x8
  43 # REL-NEXT:     0x8 R_X86_64_NONE - 0x8
  44 # REL-NEXT:     0x10 R_X86_64_NONE - 0x8
  45 # REL-NEXT:     0x18 R_X86_64_NONE - 0x8
  46 # REL-NEXT:   }
  47 # REL-NEXT: ]
  48
  49 ## -z dead-reloc-in-nonalloc= can override the tombstone value.
  50 # RUN: ld.lld --gc-sections -z dead-reloc-in-nonalloc=.debug_loc=42 %t.o %t1.o %t1.o -o %t42
  51 # RUN: llvm-objdump -s %t42 | FileCheck %s --check-prefix=OVERRIDE
  52
  53 # OVERRIDE:      Contents of section .debug_loc:
  54 # OVERRIDE-NEXT:  0000 2a000000 00000000 2a000000 00000000
  55
  56 .section .text.1,"ax"
  57   .byte 0
  58 .section .text.2,"axe"
  59   .byte 0
  60 .section .text.3,"axG",@progbits,group,comdat
  61 .globl group
  62 group:
  63   .byte 0
  64
  65 ## Resolved to UINT64_C(1), with the addend ignored.
  66 ## UINT64_C(-1) is a reserved value (base address selection entry) which can't be used.
  67 .section .debug_loc
  68   .quad .text.1+8
  69 .section .debug_ranges
  70   .quad .text.2+16
  71
  72 .section .debug_addr
  73 ## .text.3 is a local symbol. The symbol defined in a non-prevailing group is
  74 ## discarded. Resolved to UINT64_C(0).
  75   .quad .text.3+24
  76 ## group is a non-local symbol. The relocation from the second %t1.o gets
  77 ## resolved to the prevailing copy.
  78   .quad group+32
  79
  80 .section .debug_foo
  81   .quad .text.1+8
  82
  83 ## We only deal with DW_FORM_addr. Don't special case short-range absolute
  84 ## relocations. Treat them like regular absolute relocations referencing
  85 ## discarded symbols, which are resolved to the addend.
  86   .long .text.1+8
  87   .long 0