## 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: 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 0x100001008 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 PayloadString: 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 - '' ...