maxjhandsome
/
llvm-project
forked from OSchip/llvm-project
1
0
Fork 0
Code Issues Pull Requests Packages Releases Wiki Activity
llvm-project/lld/test/MachO/tlv.s

Ignoring revisions in .git-blame-ignore-revs. Click here to bypass and see the normal blame view.

119 lines
4.2 KiB
ArmAsm
Raw Normal View History

[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
# REQUIRES: x86
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
# RUN: rm -rf %t; split-file %s %t
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/regular.s -o %t/regular.o
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/tbss.s -o %t/tbss.o
[lld-macho] Don't emit rebase opcodes for relocs in TLV sections Their addresses are already encoded as section-relative offsets, so there's no need to rebase them at runtime. {D85080} has some context on the weirdness of TLV sections. Fixes llvm.org/PR48491. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D93257
2020-12-15 07:57:01 +08:00
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
# RUN: %lld -lSystem -no_pie -o %t/regular %t/regular.o
[lld/mac] Give __DATA,__thread_ptrs type S_THREAD_LOCAL_VARIABLE_POINTERS ...instead of S_NON_LAZY_SYMBOL_POINTERS. This matches ld64. Part of PR50769. While here, also remove an old TODO that was done in D87178. Differential Revision: https://reviews.llvm.org/D104594
2021-06-19 21:54:11 +08:00
# RUN: llvm-otool -hv %t/regular | FileCheck %s --check-prefix=HEADER
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
# RUN: llvm-objdump -d --bind --rebase %t/regular | FileCheck %s --check-prefixes=REG,LINKEDIT
# RUN: llvm-objdump --macho --section=__DATA,__thread_vars %t/regular | \
# RUN: FileCheck %s --check-prefix=REG-TLVP
[lld-macho] Don't emit rebase opcodes for relocs in TLV sections Their addresses are already encoded as section-relative offsets, so there's no need to rebase them at runtime. {D85080} has some context on the weirdness of TLV sections. Fixes llvm.org/PR48491. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D93257
2020-12-15 07:57:01 +08:00
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
# RUN: %lld -lSystem -pie %t/regular.o -o %t/regular-pie
[lld/mac] Give __DATA,__thread_ptrs type S_THREAD_LOCAL_VARIABLE_POINTERS ...instead of S_NON_LAZY_SYMBOL_POINTERS. This matches ld64. Part of PR50769. While here, also remove an old TODO that was done in D87178. Differential Revision: https://reviews.llvm.org/D104594
2021-06-19 21:54:11 +08:00
# RUN: llvm-otool -hv %t/regular-pie | FileCheck %s --check-prefix=HEADER
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
# RUN: llvm-objdump -d --bind --rebase %t/regular-pie | FileCheck %s --check-prefixes=REG,LINKEDIT
# RUN: llvm-objdump --macho --section=__DATA,__thread_vars %t/regular-pie | \
# RUN: FileCheck %s --check-prefix=REG-TLVP
# RUN: %lld -lSystem %t/tbss.o -o %t/tbss -e _f
# RUN: llvm-objdump -d --bind --rebase %t/tbss | FileCheck %s --check-prefixes=TBSS,LINKEDIT
# RUN: llvm-objdump --macho --section=__DATA,__thread_vars %t/tbss | \
# RUN: FileCheck %s --check-prefix=TBSS-TLVP
# RUN: %lld -lSystem %t/regular.o %t/tbss.o -o %t/regular-and-tbss
# RUN: llvm-objdump -d --bind --rebase %t/regular-and-tbss | FileCheck %s --check-prefixes=REG,TBSS,LINKEDIT
# RUN: llvm-objdump --macho --section=__DATA,__thread_vars %t/regular-and-tbss | \
# RUN: FileCheck %s --check-prefix=REG-TBSS-TLVP
# RUN: llvm-objdump --section-headers %t/regular-and-tbss | FileCheck %s --check-prefix=SECTION-ORDER
## Check that we always put __thread_bss immediately after __thread_data,
## regardless of the order of the input files.
# RUN: %lld -lSystem %t/tbss.o %t/regular.o -o %t/regular-and-tbss
# RUN: llvm-objdump --section-headers %t/regular-and-tbss | FileCheck %s --check-prefix=SECTION-ORDER
[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
# HEADER: MH_HAS_TLV_DESCRIPTORS
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
# REG: <_main>:
# REG-NEXT: leaq {{.*}}(%rip), %rax # {{.*}} <_foo>
# REG-NEXT: leaq {{.*}}(%rip), %rax # {{.*}} <_bar>
# REG-NEXT: retq
# TBSS: <_f>:
# TBSS-NEXT: leaq {{.*}}(%rip), %rax # {{.*}} <_baz>
# TBSS-NEXT: leaq {{.*}}(%rip), %rax # {{.*}} <_qux>
# TBSS-NEXT: retq
# REG-TLVP: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
# REG-TLVP-NEXT: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
# REG-TLVP-NEXT: 00 00 00 00 00 00 00 00 08 00 00 00 00 00 00 00
# TBSS-TLVP: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
# TBSS-TLVP-NEXT: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
# TBSS-TLVP-NEXT: 00 00 00 00 00 00 00 00 08 00 00 00 00 00 00 00
# REG-TBSS-TLVP: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
# REG-TBSS-TLVP-NEXT: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
# REG-TBSS-TLVP-NEXT: 00 00 00 00 00 00 00 00 08 00 00 00 00 00 00 00
# REG-TBSS-TLVP-NEXT: 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
# REG-TBSS-TLVP-NEXT: 10 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
# REG-TBSS-TLVP-NEXT: 00 00 00 00 00 00 00 00 18 00 00 00 00 00 00 00
[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
[lld-macho] Don't emit rebase opcodes for relocs in TLV sections Their addresses are already encoded as section-relative offsets, so there's no need to rebase them at runtime. {D85080} has some context on the weirdness of TLV sections. Fixes llvm.org/PR48491. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D93257
2020-12-15 07:57:01 +08:00
## Make sure we don't emit rebase opcodes for relocations in __thread_vars.
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
# LINKEDIT: Rebase table:
# LINKEDIT-NEXT: segment section address type
[llvm-objdump][MachO] Print a newline before lazy bind/bind/weak/exports trie This adds a separator between two pieces of information. Reviewed By: #lld-macho, alexshap Differential Revision: https://reviews.llvm.org/D102114
2021-05-11 00:16:18 +08:00
# LINKEDIT-EMPTY:
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
# LINKEDIT-NEXT: Bind table:
# LINKEDIT: __DATA __thread_vars 0x{{[0-9a-f]*}} pointer 0 libSystem __tlv_bootstrap
# LINKEDIT: __DATA __thread_vars 0x{{[0-9a-f]*}} pointer 0 libSystem __tlv_bootstrap
# SECTION-ORDER: __thread_data
# SECTION-ORDER: more_thread_data
# SECTION-ORDER-NEXT: __thread_bss
[lld-macho] Don't emit rebase opcodes for relocs in TLV sections Their addresses are already encoded as section-relative offsets, so there's no need to rebase them at runtime. {D85080} has some context on the weirdness of TLV sections. Fixes llvm.org/PR48491. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D93257
2020-12-15 07:57:01 +08:00
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
#--- regular.s
[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
.globl _main
_main:
mov _foo@TLVP(%rip), %rax
mov _bar@TLVP(%rip), %rax
ret
[lld-macho][nfc] Convert tabs to spaces
2021-04-12 11:23:37 +08:00
.section __DATA,__thread_data,thread_local_regular
[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
_foo$tlv$init:
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
.quad 123
[lld-macho][nfc] Convert tabs to spaces
2021-04-12 11:23:37 +08:00
.section __DATA,more_thread_data,thread_local_regular
[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
_bar$tlv$init:
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
.quad 123
[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
[lld-macho][nfc] Convert tabs to spaces
2021-04-12 11:23:37 +08:00
.section __DATA,__thread_vars,thread_local_variables
.globl _foo, _bar
[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
_foo:
[lld-macho][nfc] Convert tabs to spaces
2021-04-12 11:23:37 +08:00
.quad __tlv_bootstrap
.quad 0
.quad _foo$tlv$init
[lld-macho] Support static linking of thread-locals Note: What ELF refers to as "TLS", Mach-O seems to refer to as "TLV", i.e. thread-local variables. This diff implements support for TLV relocations that reference defined symbols. On x86_64, TLV relocations are always used with movq opcodes, so for defined TLVs, we don't need to create a synthetic section to store the addresses of the symbols -- we can just convert the `movq` to a `leaq`. One notable quirk of Mach-O's TLVs is that absolute-address relocations inside TLV-defining sections behave differently -- their addresses are no longer absolute, but relative to the start of the target section. (AFAICT, RIP-relative relocations are not allowed in these sections.) Reviewed By: #lld-macho, compnerd, smeenai Differential Revision: https://reviews.llvm.org/D85080
2020-08-08 02:04:52 +08:00
_bar:
[lld-macho][nfc] Convert tabs to spaces
2021-04-12 11:23:37 +08:00
.quad __tlv_bootstrap
.quad 0
.quad _bar$tlv$init
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
#--- tbss.s
.globl _f
_f:
mov _baz@TLVP(%rip), %rax
mov _qux@TLVP(%rip), %rax
ret
.tbss _baz$tlv$init, 8, 3
.tbss _qux$tlv$init, 8, 3
[lld-macho][nfc] Convert tabs to spaces
2021-04-12 11:23:37 +08:00
.section __DATA,__thread_vars,thread_local_variables
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
_baz:
[lld-macho][nfc] Convert tabs to spaces
2021-04-12 11:23:37 +08:00
.quad __tlv_bootstrap
.quad 0
.quad _baz$tlv$init
[lld-macho] Fix TLV data initialization We were mishandling the case where both `__tbss` and `__thread_data` sections were present. TLVP relocations should be encoded as offsets from the start of `__thread_data`, even if the symbol is actually located in `__thread_bss`. Previously, we were writing the offset from the start of the containing section, which doesn't really make sense since there's no way `tlv_get_addr()` can know which section a given `tlv$init` symbol is in at runtime. In addition, this patch ensures that we place `__thread_data` immediately before `__thread_bss`. This is what ld64 does, likely for performance reasons. Zerofill sections must also be at the end of their segments; we were already doing this, but now we ensure that `__thread_bss` occurs before `__bss`, so that it's always possible to have it contiguous with `__thread_data`. Fixes llvm.org/PR48657. Reviewed By: #lld-macho, thakis Differential Revision: https://reviews.llvm.org/D94329
2021-01-09 07:47:40 +08:00
_qux:
[lld-macho][nfc] Convert tabs to spaces
2021-04-12 11:23:37 +08:00
.quad __tlv_bootstrap
.quad 0
.quad _qux$tlv$init