## Stub dylibs differ from "real" dylibs in that they lack any content in their
## sections. What they do have are export tries and symbol tables, which means
## we can still link against them. I (jezng) am unclear how to properly create
## these stub dylibs; XCode 11.3's `lipo` is able to create stub dylibs, but
## those lack LC_ID_DYLIB load commands and are considered invalid by most
## tooling. Newer versions of `lipo` aren't able to create stub dylibs at all.
## However, recent SDKs in XCode still come with valid stub dylibs, so it still
## seems worthwhile to support them. The YAML in this test was generated by
## taking a non-stub dylib and editing the appropriate fields.
# REQUIRES: x86
# RUN: rm -rf %t; split-file %s %t
# RUN: llvm-mc -filetype=obj -triple=x86_64-apple-darwin %t/test.s -o %t/test.o
# RUN: yaml2obj %t/fat.dylib.yaml > %t/fat.dylib
# RUN: %lld -lSystem %t/test.o %t/fat.dylib -o %t/test
# RUN: llvm-objdump --macho --lazy-bind %t/test | FileCheck %s
# CHECK: __DATA __la_symbol_ptr 0x100002000 foo _foo
#--- test.s
.globl _main
_main:
callq _foo
ret
#--- fat.dylib.yaml
--- !fat-mach-o
FatHeader:
magic: 0xCAFEBABE
nfat_arch: 1
FatArchs:
- cputype: 0x01000007
cpusubtype: 0x00000003
offset: 0x0000000000001000
size: 16432
align: 12
Slices:
- !mach-o
FileHeader:
magic: 0xFEEDFACF
cputype: 0x01000007
cpusubtype: 0x00000003
filetype: 0x00000009
ncmds: 5
sizeofcmds: 568
flags: 0x00100085
reserved: 0x00000000
LoadCommands:
- cmd: LC_SEGMENT_64
cmdsize: 232
segname: __TEXT
vmaddr: 0
vmsize: 16384
fileoff: 0
filesize: 16384
maxprot: 5
initprot: 5
nsects: 1
flags: 0
Sections:
- sectname: __text
segname: __TEXT
addr: 0x0000000000000000
size: 0
offset: 0x00003FB7
align: 0
reloff: 0x00000000
nreloc: 0
flags: 0x80000400
reserved1: 0x00000000
reserved2: 0x00000000
reserved3: 0x00000000
content: ''
- cmd: LC_SEGMENT_64
cmdsize: 72
segname: __LINKEDIT
vmaddr: 16384
vmsize: 16384
fileoff: 16384
filesize: 48
maxprot: 1
initprot: 1
nsects: 0
flags: 0
- cmd: LC_ID_DYLIB
cmdsize: 40
dylib:
name: 24
timestamp: 1
current_version: 0
compatibility_version: 0
Content: foo.dylib
ZeroPadBytes: 7
- cmd: LC_DYLD_INFO_ONLY
cmdsize: 48
rebase_off: 0
rebase_size: 0
bind_off: 0
bind_size: 0
weak_bind_off: 0
weak_bind_size: 0
lazy_bind_off: 0
lazy_bind_size: 0
export_off: 16384
export_size: 16
- cmd: LC_SYMTAB
cmdsize: 24
symoff: 16408
nsyms: 1
stroff: 16424
strsize: 8
LinkEditData:
ExportTrie:
TerminalSize: 0
NodeOffset: 0
Name: ''
Flags: 0x0000000000000000
Address: 0x0000000000000000
Other: 0x0000000000000000
ImportName: ''
Children:
- TerminalSize: 3
NodeOffset: 8
Name: _foo
Flags: 0x0000000000000000
Address: 0x0000000000003FB7
Other: 0x0000000000000000
ImportName: ''
NameList:
- n_strx: 2
n_type: 0x0F
n_sect: 1
n_desc: 0
n_value: 16311
StringTable:
- ' '
- _foo
- ''
...
Codebase Browser
llvm