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[lld-macho] Put GOT into `__DATA` segment where appropriate 

We were previously always emitting the GOT into `__DATA_CONST`, even for
target platforms where it should end up in `__DATA`.

I stumbled onto this while trying to use the `class-dump` tool -- with
the wrong segment names, it fails to locate the ObjC runtime info and
therefore fails to dump any classes.

Reviewed By: #lld-macho, oontvoo

Differential Revision: https://reviews.llvm.org/D112500
This commit is contained in:
Jez Ng 2021-10-26 11:36:09 -04:00
parent 2174524116
commit 622150ad5f
2 changed files with 20 additions and 15 deletions
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2
lld/MachO/SyntheticSections.cpp
View File

@ -259,7 +259,7 @@ void NonLazyPointerSectionBase::writeTo(uint8_t *buf) const {
}
GotSection::GotSection()
: NonLazyPointerSectionBase(segment_names::dataConst, section_names::got) {
: NonLazyPointerSectionBase(segment_names::data, section_names::got) {
flags = S_NON_LAZY_SYMBOL_POINTERS;
}

33
lld/test/MachO/builtin-rename.s
View File

@ -55,6 +55,23 @@
# YDATA-DAG: __DATA_CONST,__objc_imageinfo __DATA__objc_imageinfo
# YDATA-DAG: __DATA_CONST,__nl_symbol_ptr __IMPORT__pointers
## LLD doesn't support defining symbols in synthetic sections, so we test them
## via this slightly more awkward route.
# RUN: llvm-readobj --section-headers %t/ydata | \
# RUN: FileCheck %s --check-prefix=SYNTH -DSEGNAME=__DATA_CONST
# RUN: llvm-readobj --section-headers %t/ndata | \
# RUN: FileCheck %s --check-prefix=SYNTH -DSEGNAME=__DATA
# RUN: llvm-readobj --section-headers %t/nopie | \
# RUN: FileCheck %s --check-prefix=SYNTH -DSEGNAME=__DATA
# RUN: llvm-readobj --section-headers %t/old | \
# RUN: FileCheck %s --check-prefix=SYNTH -DSEGNAME=__DATA
# SYNTH: Name: __got
# SYNTH-NEXT: Segment: [[SEGNAME]] ({{.*}})
## Note that __la_symbol_ptr always remains in the non-const data segment.
# SYNTH: Name: __la_symbol_ptr
# SYNTH-NEXT: Segment: __DATA ({{.*}})
#--- renames.s
.section __DATA,__auth_got
.global __DATA__auth_got
@ -81,13 +98,6 @@ __DATA__const:
__DATA__cfstring:
.space 8
# FIXME: error: conflicts with synthetic section ...
# FIXME: we can't explicitly define syms in synthetic sections
# COM: .section __DATA,__got
# COM: .global __DATA__got
# COM: __DATA__got:
# COM: .space 8
.section __DATA,__mod_init_func,mod_init_funcs
.global __DATA__mod_init_func
__DATA__mod_init_func:
@ -128,13 +138,6 @@ __DATA__objc_protolist:
__DATA__objc_imageinfo:
.space 8
# FIXME: error: conflicts with synthetic section ...
# FIXME: we can't explicitly define syms in synthetic sections
# COM: .section __DATA,__la_symbol_ptr,lazy_symbol_pointers
# COM: .global __DATA__la_symbol_ptr
# COM: __DATA__la_symbol_ptr:
# COM: .space 8
.section __IMPORT,__pointers,non_lazy_symbol_pointers
.global __IMPORT__pointers
__IMPORT__pointers:
@ -150,4 +153,6 @@ __TEXT__StaticInit:
.text
.global _main
_main:
mov ___nan@GOTPCREL(%rip), %rax ## ensure the __got section is created
callq ___isnan ## ensure the __la_symbol_ptr section is created
ret