lld/test/ELF/why-live.test

# REQUIRES: x86

# RUN: rm -rf %t && split-file %s %t && cd %t
# RUN: llvm-mc -n -filetype=obj -triple=x86_64 -o shared.o shared.s
# RUN: ld.lld -shared shared.o -o a.so
# RUN: llvm-mc -n -filetype=obj -triple=x86_64 -o a.o a.s

#--- shared.s
.globl test_shared
.section .test_shared,"ax",@progbits
test_shared:
  jmp test_shared

#--- a.s
## Simple live section
.globl _start
.section ._start,"ax",@progbits
_start:
  jmp test_simple
  .quad .Lanonymous
  .quad .Lanonymous_within_symbol
  jmp test_shared
  .quad test_local
.size _start, .-_start

.globl test_simple
.section .test_simple,"ax",@progbits
test_simple:
  jmp test_simple
  jmp test_from_unsized

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_simple | FileCheck %s --check-prefix=SIMPLE

# SIMPLE:      live symbol: a.o:(test_simple)
# SIMPLE-NEXT: >>> referenced by: a.o:(_start) (entry point)
# SIMPLE-EMPTY:

## Live only by being a member of .test_simple
.globl test_incidental
test_incidental:
  jmp test_incidental

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_incidental | FileCheck %s --check-prefix=INCIDENTAL

# INCIDENTAL:      live symbol: a.o:(test_incidental)
# INCIDENTAL-NEXT: >>> in live section: a.o:(.test_simple)
# INCIDENTAL-NEXT: >>> contained live symbol: a.o:(test_simple)
# INCIDENTAL-NEXT: >>> referenced by: a.o:(_start) (entry point)
# INCIDENTAL-EMPTY:

## Reached from a reference in section .test_simple directly, since test_simple is an unsized symbol.
.globl test_from_unsized
.section .test_from_unsized,"ax",@progbits
test_from_unsized:
  jmp test_from_unsized

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_from_unsized | FileCheck %s --check-prefix=FROM-UNSIZED

# FROM-UNSIZED:      live symbol: a.o:(test_from_unsized)
# FROM-UNSIZED-NEXT: >>> referenced by: a.o:(.test_simple)
# FROM-UNSIZED-NEXT: >>> contained live symbol: a.o:(test_simple)
# FROM-UNSIZED-NEXT: >>> referenced by: a.o:(_start) (entry point)
# FROM-UNSIZED-EMPTY:

## Symbols in dead sections are dead and not reported.
.globl test_dead
.section .test_dead,"ax",@progbits
test_dead:
  jmp test_dead

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_dead | count 0

## Undefined symbols are considered live, since they are not in dead sections.

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_undef -u test_undef | FileCheck %s --check-prefix=UNDEFINED

# UNDEFINED:     live symbol: <internal>:(test_undef) (no section)
# UNDEFINED-EMPTY:

## Defined symbols without input section parents are live.
.globl test_absolute
test_absolute = 1234

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_absolute | FileCheck %s --check-prefix=ABSOLUTE

# ABSOLUTE:     live symbol: a.o:(test_absolute) (no section)
# ABSOLUTE-EMPTY:

## Retained sections are intrinsically live, and they make contained symbols live.
.globl test_retained
.section .test_retained,"axR",@progbits
test_retained:
  jmp test_retained

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_retained | FileCheck %s --check-prefix=RETAINED

# RETAINED:      live symbol: a.o:(test_retained)
# RETAINED-NEXT: >>> in live section: a.o:(.test_retained) (retained)
# RETAINED-EMPTY:

## Relocs that reference offsets from sections (e.g., from anonymous symbols) are considered to point to the section if no enclosing symbol exists.

.globl test_section_offset
.section .test_section_offset,"ax",@progbits
test_section_offset:
  jmp test_section_offset
.Lanonymous:
  jmp test_section_offset

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_section_offset | FileCheck %s --check-prefix=SECTION-OFFSET

# SECTION-OFFSET:      live symbol: a.o:(test_section_offset)
# SECTION-OFFSET-NEXT: >>> in live section: a.o:(.test_section_offset)
# SECTION-OFFSET-NEXT: >>> referenced by: a.o:(_start) (entry point)
# SECTION-OFFSET-EMPTY:

## Relocs that reference offsets from sections (e.g., from anonymous symbols) are considered to point to the enclosing symbol if one exists.

.globl test_section_offset_within_symbol
.section .test_section_offset_within_symbol,"ax",@progbits
test_section_offset_within_symbol:
  jmp test_section_offset_within_symbol
.Lanonymous_within_symbol:
  jmp test_section_offset_within_symbol
.size test_section_offset_within_symbol, .-test_section_offset_within_symbol

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_section_offset_within_symbol | FileCheck %s --check-prefix=SECTION-OFFSET-WITHIN-SYMBOL

# SECTION-OFFSET-WITHIN-SYMBOL:      live symbol: a.o:(test_section_offset_within_symbol)
# SECTION-OFFSET-WITHIN-SYMBOL-NEXT: >>> referenced by: a.o:(_start) (entry point)
# SECTION-OFFSET-WITHIN-SYMBOL-EMPTY:

## Local symbols can be queried just like global symbols.

.section .test_local,"ax",@progbits
test_local:
  jmp test_local
.size test_local, .-test_local

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_local | FileCheck %s --check-prefix=LOCAL

# LOCAL:      live symbol: a.o:(test_local)
# LOCAL-NEXT: >>> referenced by: a.o:(_start) (entry point)
# LOCAL-EMPTY:

## Shared symbols

# RUN: ld.lld a.o a.so --gc-sections --why-live=test_shared | FileCheck %s --check-prefix=SHARED

# SHARED:      live symbol: a.so:(test_shared)
# SHARED-NEXT: >>> referenced by: a.o:(_start) (entry point)
# SHARED-EMPTY:

## Globs match multiple cases. Multiple --why-live flags union.

# RUN: ld.lld a.o a.so --gc-sections --why-live="test_se*" --why-live="test_se*" | FileCheck %s --check-prefix=MULTIPLE
# RUN: ld.lld a.o a.so --gc-sections --why-live=test_section_offset --why-live=test_section_offset_within_symbol | FileCheck %s --check-prefix=MULTIPLE

# MULTIPLE-DAG: live symbol: a.o:(test_section_offset)
# MULTIPLE-DAG: live symbol: a.o:(test_section_offset_within_symbol)
# MULTIPLE-NOT: live symbol