Open
Description
... which sounds reasonable, but breaks an assumption in install_name_tool:
$ cat myfoobar.c
int foobar(int a, int b) {
return a + b;
}
$ clang -v -dynamiclib myfoobar.c -o liba.dylib
$ clang -v -dynamiclib -o libdummy-ld64.dylib -L`pwd` -la
$ clang -v -dynamiclib -o libdummy-lld.dylib -fuse-ld=/path/to/ld64.lld -L`pwd` -la
$ otool -l libdummy-ld64.dylib
libdummy-ld64.dylib:
Load command 0
cmd LC_SEGMENT_64
cmdsize 152
segname __TEXT
vmaddr 0x0000000000000000
vmsize 0x0000000000004000
fileoff 0
filesize 16384
maxprot 0x00000005
initprot 0x00000005
nsects 1
flags 0x0
Section
sectname __text
segname __TEXT
addr 0x0000000000004000
size 0x0000000000000000
[...]
$ otool -l libdummy-lld.dylib
libdummy-lld.dylib:
Load command 0
cmd LC_SEGMENT_64
cmdsize 72
segname __TEXT
vmaddr 0x0000000000000000
vmsize 0x0000000000004000
fileoff 0
filesize 16384
maxprot 0x00000005
initprot 0x00000005
nsects 0
flags 0x0
[...]
$ install_name_tool -id @rpath/liba.dylib libdummy-ld64.dylib # works fine
$ install_name_tool -id @rpath/liba.dylib libdummy-lld.dylib
error: /Applications/Xcode15beta8.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/bin/install_name_tool: changing install names or rpaths can't be redone for: libdummy-lld.dylib (for architecture arm64) because larger updated load commands do not fit (the program must be relinked, and you may need to use -headerpad or -headerpad_max_install_names)
The error message is a bit misleading. If I understand correctly install_name_tool just assumes that __text exists:
- https://github.com/opensource-apple/cctools/blob/fdb4825f303fd5c0751be524babd32958181b3ed/misc/install_name_tool.c#L763-L778
- https://github.com/opensource-apple/cctools/blob/fdb4825f303fd5c0751be524babd32958181b3ed/misc/install_name_tool.c#L842-L849
Using -Wl,-add_empty_section,__TEXT,__text fixes the problem, but I think it would be nice if ld64.lld has the same behaviour in that area.