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Differential D78269

[lld-macho] Support X86_64_RELOC_BRANCH
ClosedPublic

Authored by int3 on Apr 15 2020, 9:45 PM.

Details

Reviewers
ruiu
pcc
MaskRay
smeenai
alexander-shaposhnikov
gkm
Ktwu
christylee
Commits
rGe82c5e17b58f: [lld-macho] Support X86_64_RELOC_BRANCH
Summary

Relatively straightforward diff, to set the stage for calling functions
in dylibs.

Depends on D78168.

Diff Detail

Event Timeline

int3 created this revision.Apr 15 2020, 9:45 PM
Herald added a project: Restricted Project. · View Herald TranscriptApr 15 2020, 9:45 PM
Herald added a subscriber: llvm-commits. · View Herald Transcript
int3 added a child revision: D78270: [lld-macho] Support calls to functions in dylibs.Apr 15 2020, 9:47 PM
Harbormaster failed remote builds in B53503: Diff 257954!Apr 15 2020, 10:02 PM
int3 updated this revision to Diff 258147.Apr 16 2020, 12:57 PM

rebase

Harbormaster failed remote builds in B53624: Diff 258147!Apr 16 2020, 1:25 PM
smeenai accepted this revision.Apr 23 2020, 6:36 PM

LGTM

lld/test/MachO/relocations.s
6–17

I really like the offset checking :)

This revision is now accepted and ready to land.Apr 23 2020, 6:36 PM
int3 updated this revision to Diff 260437.Apr 27 2020, 1:10 PM

rebase

Harbormaster failed remote builds in B54863: Diff 260437!Apr 27 2020, 2:01 PM
MaskRay accepted this revision.Apr 27 2020, 2:18 PM
MaskRay added inline comments.
lld/test/MachO/relocations.s
7

# CHECK:

10

# CHECK:

MaskRay added inline comments.Apr 27 2020, 2:20 PM
lld/test/MachO/relocations.s
12

Consider changing Disassembly of section __TEXT,__text: to something like CHECK-LABEL: <_main>:

It is obvious that the code is in __TEXT,__text: so the information adds very little value. On the contrary, <_main>: conveys a bit more useful information.

int3 marked 4 inline comments as done.Apr 28 2020, 11:08 PM
int3 added inline comments.
lld/test/MachO/relocations.s
7

The -DAG was so that future entries could be added w/o changing this line, but sure

int3 updated this revision to Diff 260843.Apr 28 2020, 11:08 PM
int3 marked an inline comment as done.

address comments

Harbormaster failed remote builds in B55084: Diff 260843!Apr 28 2020, 11:12 PM
int3 updated this revision to Diff 261032.Apr 29 2020, 2:13 PM

rebase

Harbormaster failed remote builds in B55189: Diff 261032!Apr 29 2020, 3:07 PM
Closed by commit rGe82c5e17b58f: [lld-macho] Support X86_64_RELOC_BRANCH (authored by int3, committed by smeenai). · Explain WhyApr 29 2020, 4:13 PM
This revision was automatically updated to reflect the committed changes.
int3 added a child revision: D77893: [lld] Merge Mach-O input sections.May 1 2020, 5:06 PM
int3 removed a child revision: D78270: [lld-macho] Support calls to functions in dylibs.May 5 2020, 5:39 PM
int3 added a child revision: D78270: [lld-macho] Support calls to functions in dylibs.May 5 2020, 5:40 PM
int3 removed a child revision: D78270: [lld-macho] Support calls to functions in dylibs.May 5 2020, 10:48 PM

Revision Contents

PathSize
lld/
MachO/
Arch/
2 lines
test/
MachO/
23 lines

Diff 257954

lld/MachO/Arch/X86_64.cpp

//===- X86_64.cpp ---------------------------------------------------------===// //===- X86_64.cpp ---------------------------------------------------------===//
Lint: Lint
Inline Actions

clang-format-diff not found in user's PATH; not linting file.

Lint: Lint: clang-format-diff not found in user's PATH; not linting file.
// //
// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions. // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
// See https://llvm.org/LICENSE.txt for license information. // See https://llvm.org/LICENSE.txt for license information.
// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
// //
//===----------------------------------------------------------------------===// //===----------------------------------------------------------------------===//
Show All 17 Lines
X86_64::X86_64() { X86_64::X86_64() {
cpuType = CPU_TYPE_X86_64; cpuType = CPU_TYPE_X86_64;
cpuSubtype = CPU_SUBTYPE_X86_64_ALL; cpuSubtype = CPU_SUBTYPE_X86_64_ALL;
} }
uint64_t X86_64::getImplicitAddend(const uint8_t *loc, uint8_t type) const { uint64_t X86_64::getImplicitAddend(const uint8_t *loc, uint8_t type) const {
switch (type) { switch (type) {
case X86_64_RELOC_BRANCH:
case X86_64_RELOC_SIGNED: case X86_64_RELOC_SIGNED:
case X86_64_RELOC_GOT_LOAD: case X86_64_RELOC_GOT_LOAD:
return read32le(loc); return read32le(loc);
default: default:
error("TODO: Unhandled relocation type " + std::to_string(type)); error("TODO: Unhandled relocation type " + std::to_string(type));
return 0; return 0;
} }
} }
void X86_64::relocateOne(uint8_t *loc, uint8_t type, uint64_t val) const { void X86_64::relocateOne(uint8_t *loc, uint8_t type, uint64_t val) const {
switch (type) { switch (type) {
case X86_64_RELOC_BRANCH:
case X86_64_RELOC_SIGNED: case X86_64_RELOC_SIGNED:
case X86_64_RELOC_GOT_LOAD: case X86_64_RELOC_GOT_LOAD:
// These types are only used for pc-relative relocations, so offset by 4 // These types are only used for pc-relative relocations, so offset by 4
// since the RIP has advanced by 4 at this point. // since the RIP has advanced by 4 at this point.
write32le(loc, val - 4); write32le(loc, val - 4);
break; break;
default: default:
llvm_unreachable( llvm_unreachable(
Show All 10 Lines

lld/test/MachO/relocations.s

# REQUIRES: x86 # REQUIRES: x86
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o # RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %s -o %t.o
# RUN: lld -flavor darwinnew -o %t %t.o # RUN: lld -flavor darwinnew -o %t %t.o
# RUN: llvm-objdump -d %t | FileCheck %s # RUN: llvm-objdump --section-headers --syms -d %t | FileCheck %s
# CHECK: leaq 17(%rip), %rsi # CHECK-LABEL: Sections:
# CHECK-DAG: __cstring {{[0-9a-z]+}} [[#%x, CSTRING_ADDR:]]
MaskRayUnsubmitted
Done
ReplyInline Actions

# CHECK:

MaskRay: `# CHECK:`
int3AuthorUnsubmitted
Done
ReplyInline Actions

The -DAG was so that future entries could be added w/o changing this line, but sure

int3: The `-DAG` was so that future entries could be added w/o changing this line, but sure
# CHECK-LABEL: SYMBOL TABLE:
# CHECK-DAG: [[#%x, F_ADDR:]] {{.*}} _f
MaskRayUnsubmitted
Done
ReplyInline Actions

# CHECK:

MaskRay: `# CHECK: `
# CHECK-LABEL: Disassembly of section __TEXT,__text:
MaskRayUnsubmitted
Done
ReplyInline Actions

Consider changing Disassembly of section __TEXT,__text: to something like CHECK-LABEL: <_main>:

It is obvious that the code is in __TEXT,__text: so the information adds very little value. On the contrary, <_main>: conveys a bit more useful information.

MaskRay: Consider changing `Disassembly of section __TEXT,__text:` to something like `CHECK-LABEL…
## Test X86_64_RELOC_BRANCH
# CHECK: callq 0x[[#%x, F_ADDR]] <_f>
## Test X86_64_RELOC_SIGNED
# CHECK: leaq [[#%u, STR_OFF:]](%rip), %rsi
# CHECK-NEXT: [[#%x, CSTRING_ADDR - STR_OFF]]
smeenaiUnsubmitted
Not Done
ReplyInline Actions

I really like the offset checking :)

smeenai: I really like the offset checking :)
.section __TEXT,__text .section __TEXT,__text
.globl _main .globl _main, _f
_main: _main:
callq _f
mov $0, %rax
ret
_f:
movl $0x2000004, %eax # write() syscall movl $0x2000004, %eax # write() syscall
mov $1, %rdi # stdout mov $1, %rdi # stdout
leaq str(%rip), %rsi leaq str(%rip), %rsi
mov $13, %rdx # length of str mov $13, %rdx # length of str
syscall syscall
mov $0, %rax
ret ret
.section __TEXT,__cstring .section __TEXT,__cstring
str: str:
.asciz "Hello world!\n" .asciz "Hello world!\n"