[LLD] lld linker script does not support library: or :file file descriptor patterns #119584
Description
This was found by an internal project while trying to migrate from a GNU toolchain to a LLVM based toolchain.
The GNU ld manual https://sourceware.org/binutils/docs/ld/Input-Section-Basics.html has the following section:
You can also specify files within archives by writing a pattern matching the archive, a colon, then the pattern matching the file, with no whitespace around the colon.
‘archive:file’
matches file within archive
‘archive:’
matches the whole archive
‘:file’
matches file but not one in an archive
LLD will support archive:file but it does not support archive: or :file.
For example:
app.s
.text
.global _start
.type _start, %function
.global foo
_start: call foo
lib.s
.text
.global foo
.type foo, %function
foo: nop
app.ld
SECTIONS {
lib : { lib.a:(*.text) } /* Expect lib.a(lib.o):(.text) */
app : { :app.o(*.text) } /* Expect app.o(.text) */
all : { *(.text) } /* Expect no matches */
}
clang --target=x86_64 -c app.s lib.s
llvm-ar -rcs lib.a lib.o
ld.ldd app.o lib.a --script=app.ld --print-map
VMA LMA Size Align Out In Symbol
0 0 9 4 all
0 0 5 4 app.o:(.text)
0 0 0 1 _start
8 8 1 4 lib.a(lib.o):(.text)
8 8 0 1 foo
We can see the .text has been matched by all. GNU ld matches as we would expect:
ld.bfd app.o lib.a --script=app.ld --print-map
lib 0x0000000000000000 0x1
lib.a:(*.text)
.text 0x0000000000000000 0x1 lib.a(lib.o)
0x0000000000000000 foo
app 0x0000000000000004 0x5
:app.o(*.text)
.text 0x0000000000000004 0x5 app.o
0x0000000000000004 _start
There is a workaround for the library pattern by using library:* but I can't think of one for the :file