llvm-capstone/bolt/test/X86/gotpcrelx.s
Maksim Panchenko 43f56a2f27 [BOLT] Fix handling of code references from unmodified code
In lite mode (default for X86), BOLT optimizes and relocates functions
with profile. The rest of the code is preserved, but if it references
relocated code such references have to be updated. The update is handled
by scanExternalRefs() function. Note that we cannot solely rely on
relocations written by the linker, as not all code references are
exposed to the linker. Additionally, the linker can modify certain
instructions and relocations will no longer match the code.

With this change, start using symbolic disassembler for scanning code
for references in scanExternalRefs(). Unlike the previous approach, the
symbolizer properly detects and creates references for instructions with
multiple/ambiguous symbolic operands and handles cases where a
relocation doesn't match any operand. See test cases for examples.

Reviewed By: Amir

Differential Revision: https://reviews.llvm.org/D152631
2023-06-12 10:46:51 -07:00

85 lines
2.8 KiB
ArmAsm

# REQUIRES: system-linux
## Check that BOLT correctly handles different types of instructions with
## R_X86_64_GOTPCRELX or R_X86_64_REX_GOTPCRELX relocations and different
## kinds of handling of the relocation by the linker (no relaxation, pic, and
## non-pic).
# RUN: llvm-mc -filetype=obj -triple x86_64-unknown-linux \
# RUN: -relax-relocations %s -o %t.o
# RUN: ld.lld %t.o -o %t.exe -q
# RUN: ld.lld %t.o -o %t.pie.exe -q -pie
# RUN: ld.lld %t.o -o %t.no-relax.exe -q --no-relax
# RUN: llvm-bolt %t.exe --relocs -o %t.out --print-cfg --print-only=_start \
# RUN: |& FileCheck --check-prefix=BOLT %s
# RUN: llvm-bolt %t.pie.exe -o /dev/null --print-cfg --print-only=_start \
# RUN: |& FileCheck --check-prefix=PIE-BOLT %s
# RUN: llvm-bolt %t.no-relax.exe -o /dev/null --print-cfg --print-only=_start \
# RUN: |& FileCheck --check-prefix=NO-RELAX-BOLT %s
# RUN: llvm-objdump -d --no-show-raw-insn --print-imm-hex \
# RUN: %t.out | FileCheck --check-prefix=DISASM %s
## Relocate foo only and check that code references from _start (that is
## otherwise preserved) are updated.
# RUN: llvm-bolt %t.exe --relocs -o %t.lite.out --funcs=foo
# RUN: llvm-objdump -d --no-show-raw-insn --print-imm-hex \
# RUN: %t.lite.out | FileCheck --check-prefix=DISASM %s
.text
.globl _start
.type _start, %function
_start:
.cfi_startproc
# DISASM: <_start>:
call *foo@GOTPCREL(%rip)
# NO-RELAX-BOLT: callq *{{.*}}(%rip)
# BOLT: callq foo
# PIE-BOLT: callq foo
# DISASM-NEXT: callq 0x[[#%x,ADDR:]]
movq foo@GOTPCREL(%rip), %rdi
# NO-RELAX-BOLT-NEXT: movq {{.*}}(%rip), %rdi
# BOLT-NEXT: leaq foo(%rip), %rdi
# PIE-BOLT-NEXT: leaq foo(%rip), %rdi
# DISASM-NEXT: leaq {{.*}}(%rip), %rdi # 0x[[#ADDR]]
movl foo@GOTPCREL+4(%rip), %edi
# NO-RELAX-BOLT-NEXT: movl {{.*}}(%rip), %edi
# BOLT-NEXT: movl {{.*}}(%rip), %edi
# PIE-BOLT-NEXT: movl {{.*}}(%rip), %edi
# DISASM-NEXT: movl {{.*}}(%rip), %edi
test %rdi, foo@GOTPCREL(%rip)
# NO-RELAX-BOLT-NEXT: testq %rdi, DATA{{.*}}(%rip)
# BOLT-NEXT: testq $foo, %rdi
# PIE-BOLT-NEXT: testq %rdi, DATA{{.*}}(%rip)
# DISASM-NEXT: testq $0x[[#ADDR]], %rdi
cmpq foo@GOTPCREL(%rip), %rax
# NO-RELAX-BOLT-NEXT: cmpq DATA{{.*}}(%rip), %rax
# BOLT-NEXT: cmpq $foo, %rax
# PIE-BOLT-NEXT: cmpq DATA{{.*}}(%rip), %rax
# DISASM-NEXT: cmpq $0x[[#ADDR]], %rax
jmp *foo@GOTPCREL(%rip)
# NO-RELAX-BOLT-NEXT: jmpq *DATA{{.*}}(%rip)
# BOLT-NEXT: jmp foo
# PIE-BOLT-NEXT: jmp foo
# DISASM-NEXT: jmp 0x[[#ADDR]]
# DISASM: [[#ADDR]] <foo>:
ret
.cfi_endproc
.size _start, .-_start
.globl foo
.type foo, %function
foo:
.cfi_startproc
ret
.cfi_endproc
.size foo, .-foo