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

   1 # REQUIRES: aarch64, 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 # RUN: echo '.globl _start; _start: bl group' | llvm-mc -filetype=obj -triple=aarch64 - -o %t.a64.o
  13 # RUN: llvm-mc -filetype=obj -triple=aarch64 %s -o %t1.a64.o
  14 # RUN: ld.lld --emit-relocs --gc-sections %t.a64.o %t1.a64.o %t1.a64.o -o %t.a64
  15 # RUN: llvm-objdump -s %t.a64 | FileCheck %s
  16
  17 # CHECK:      Contents of section .debug_loc:
  18 # CHECK-NEXT:  0000 01000000 00000000 01000000 00000000
  19 # CHECK:      Contents of section .debug_ranges:
  20 # CHECK-NEXT:  0000 01000000 00000000 01000000 00000000
  21 # CHECK:      Contents of section .debug_addr:
  22 # CHECK-NEXT:  0000 {{.*}}00 00000000 {{.*}}00 00000000
  23 # CHECK-NEXT:  0010 00000000 00000000 {{.*}}00 00000000
  24 # CHECK:      Contents of section .debug_names:
  25 # CHECK-NEXT:  0000 00000000 00000000 00000000 ffffffff .
  26 # CHECK-NEXT:  0010 ffffffff ffffffff                   .
  27 # CHECK:      Contents of section .debug_foo:
  28 # CHECK-NEXT:  0000 00000000 00000000 00000000 00000000
  29 # CHECK-NEXT:  0010 00000000 00000000 00000000 00000000
  30
  31 # REL:      Relocations [
  32 # REL-NEXT:   .rela.text {
  33 # REL-NEXT:     0x201121 R_X86_64_PLT32 group 0xFFFFFFFFFFFFFFFC
  34 # REL-NEXT:   }
  35 # REL-NEXT:   .rela.debug_loc {
  36 # REL-NEXT:     0x0 R_X86_64_NONE - 0x8
  37 # REL-NEXT:     0x8 R_X86_64_NONE - 0x8
  38 # REL-NEXT:   }
  39 # REL-NEXT:   .rela.debug_ranges {
  40 # REL-NEXT:     0x0 R_X86_64_NONE - 0x10
  41 # REL-NEXT:     0x8 R_X86_64_NONE - 0x10
  42 # REL-NEXT:   }
  43 # REL-NEXT:   .rela.debug_addr {
  44 # REL-NEXT:     0x0 R_X86_64_64 .text 0x1D
  45 # REL-NEXT:     0x8 R_X86_64_64 group 0x20
  46 # REL-NEXT:     0x10 R_X86_64_NONE - 0x18
  47 # REL-NEXT:     0x18 R_X86_64_64 group 0x20
  48 # REL-NEXT:   }
  49 # REL-NEXT:   .rela.debug_names {
  50 # REL-NEXT:     0x0 R_X86_64_32 .debug_info 0x0
  51 # REL-NEXT:     0x4 R_X86_64_64 .debug_info 0x0
  52 # REL-NEXT:     0xC R_X86_64_NONE - 0x0
  53 # REL-NEXT:     0x10 R_X86_64_NONE - 0x0
  54 # REL-NEXT:   }
  55 # REL-NEXT:   .rela.debug_foo {
  56 # REL-NEXT:     0x0 R_X86_64_NONE - 0x8
  57 # REL-NEXT:     0x8 R_X86_64_NONE - 0x8
  58 # REL-NEXT:     0x10 R_X86_64_NONE - 0x8
  59 # REL-NEXT:     0x18 R_X86_64_NONE - 0x8
  60 # REL-NEXT:   }
  61 # REL-NEXT: ]
  62
  63 ## -z dead-reloc-in-nonalloc= can override the tombstone value.
  64 # RUN: ld.lld --gc-sections -z dead-reloc-in-nonalloc=.debug_loc=42 %t.o %t1.o %t1.o -o %t42
  65 # RUN: llvm-objdump -s %t42 | FileCheck %s --check-prefix=OVERRIDE
  66
  67 # OVERRIDE:      Contents of section .debug_loc:
  68 # OVERRIDE-NEXT:  0000 2a000000 00000000 2a000000 00000000
  69
  70 .section .text.1,"ax"
  71   .byte 0
  72 .section .text.2,"axe"
  73   .byte 0
  74 .section .text.3,"axG",@progbits,group,comdat
  75 .globl group
  76 group:
  77   .byte 0
  78
  79 ## Resolved to UINT64_C(1), with the addend ignored.
  80 ## UINT64_C(-1) is a reserved value (base address selection entry) which can't be used.
  81 .section .debug_loc
  82   .quad .text.1+8
  83 .section .debug_ranges
  84   .quad .text.2+16
  85
  86 .section .debug_addr
  87 ## .text.3 is a local symbol. The symbol defined in a non-prevailing group is
  88 ## discarded. Resolved to UINT64_C(0).
  89   .quad .text.3+24
  90 ## group is a non-local symbol. The relocation from the second %t1.o gets
  91 ## resolved to the prevailing copy.
  92   .quad group+32
  93
  94 .section  .debug_info,"G",@progbits,5657452045627120676,comdat
  95 .Ltu_begin0:
  96
  97 .section .debug_names
  98 ## .debug_names may reference a local type unit defined in a COMDAT .debug_info
  99 ## section (-g -gpubnames -fdebug-types-section). If the referenced section is
 100 ## non-prevailing, resolve to UINT32_MAX.
 101 .long .Ltu_begin0
 102 ## ... or UINT64_MAX for DWARF64.
 103 .quad .Ltu_begin0
 104
 105 .section .debug_foo
 106   .quad .text.1+8
 107
 108 ## We only deal with DW_FORM_addr. Don't special case short-range absolute
 109 ## relocations. Treat them like regular absolute relocations referencing
 110 ## discarded symbols, which are resolved to the addend.
 111   .long .text.1+8
 112   .long 0