lld/test/ELF/relocatable-gc.s

   1 # REQUIRES: x86
   2 ## Test -r --gc-sections.
   3
   4 # RUN: llvm-mc -filetype=obj -triple=x86_64 %s -o %t.o
   5
   6 ## By default all regular sections are discarded. We currently don't track
   7 ## usage of group signature symbols and will retain them and their associated
   8 ## STT_SECTION symbols.
   9 # RUN: ld.lld -r --gc-sections --print-gc-sections %t.o -o %t
  10 # RUN: llvm-readelf -S -s %t | FileCheck %s
  11
  12 # CHECK:      [ 1] .group
  13 # CHECK-NEXT: [ 2] .note.GNU-stack
  14
  15 # CHECK:      Symbol table '.symtab' contains 3 entries:
  16 # CHECK-NEXT: Num:
  17 # CHECK-NEXT: 0:
  18 # CHECK-NEXT: 1: {{.*}} NOTYPE  LOCAL DEFAULT  1 group
  19 # CHECK-NEXT: 2: {{.*}} SECTION LOCAL DEFAULT  1
  20
  21 ## -u keeps .text.bar alive. Other group members are kept alive as well.
  22 # RUN: ld.lld -r --gc-sections -u bar %t.o -o - | llvm-readelf -Ss - | \
  23 # RUN:   FileCheck %s --check-prefix=KEEP_GROUP
  24 ## -e, --init and --fini are similar.
  25 # RUN: ld.lld -r --gc-sections -e bar %t.o -o - | llvm-readelf -Ss - | \
  26 # RUN:   FileCheck %s --check-prefix=KEEP_GROUP
  27 # RUN: ld.lld -r --gc-sections --init=bar %t.o -o - | llvm-readelf -Ss - | \
  28 # RUN:   FileCheck %s --check-prefix=KEEP_GROUP
  29 # RUN: ld.lld -r --gc-sections --fini=bar %t.o -o - | llvm-readelf -Ss - | \
  30 # RUN:   FileCheck %s --check-prefix=KEEP_GROUP
  31
  32 # KEEP_GROUP:      [ 1] .group
  33 # KEEP_GROUP-NEXT: [ 2] .text.bar
  34 # KEEP_GROUP-NEXT: [ 3] .text.foo
  35 # KEEP_GROUP-NEXT: [ 4] .note.GNU-stack
  36
  37 # KEEP_GROUP:      Symbol table '.symtab' contains 7 entries:
  38 # KEEP_GROUP:      4: {{.*}} SECTION
  39 # KEEP_GROUP-NEXT: 5: {{.*}}   2 bar
  40 # KEEP_GROUP-NEXT: 6: {{.*}}   3 foo
  41
  42 ## If .text is retained, its referenced qux and .fred are retained as well.
  43 ## fred_und is used (by .fred) and thus emitted.
  44 ## Note, GNU ld does not retain qux.
  45 # RUN: ld.lld -r --gc-sections -z nostart-stop-gc -e _start %t.o -o %tstart.ro
  46 # RUN: llvm-readelf -Ss %tstart.ro | FileCheck %s --check-prefix=KEEP_START
  47
  48 # KEEP_START:      [ 1] .text
  49 # KEEP_START-NEXT: [ 2] .rela.text
  50 # KEEP_START-NEXT: [ 3] qux
  51 # KEEP_START-NEXT: [ 4] .group
  52 # KEEP_START-NEXT: [ 5] .fred
  53 # KEEP_START-NEXT: [ 6] .rela.fred
  54 # KEEP_START-NEXT: [ 7] .note.GNU-stack
  55
  56 # KEEP_START:      Symbol table '.symtab' contains 10 entries:
  57 # KEEP_START:      5: {{.*}} SECTION
  58 # KEEP_START-NEXT: 6: {{.*}}   1 _start
  59 # KEEP_START-NEXT: 7: {{.*}}   5 fred
  60 # KEEP_START-NEXT: 8: {{.*}} UND __start_qux
  61 # KEEP_START-NEXT: 9: {{.*}} UND fred_und
  62
  63 .section qux,"a",@progbits
  64   .byte 0
  65
  66 .text
  67 .globl _start, bar, foo, fred
  68 _start:
  69   call fred
  70   .quad __start_qux
  71
  72 .section .text.bar,"axG",@progbits,group,comdat
  73 bar:
  74   .byte 1
  75 .section .text.foo,"axG",@progbits,group,comdat
  76 foo:
  77   .byte 2
  78 .section .fred,"ax",@progbits
  79 fred:
  80   call fred_und