Fix search order in INPUT and GROUP of script

[demin-han]

The scenario is from incremental cross compiling gcc. libgcc_s.so is a ld script in my OS.
GROUP ( libgcc_s.so.1 -lgcc )
The path of libgcc_s.so.1 is not absolute.
When current directory contains libgcc_s.so.1 of other ISA, We will get target of other ISA and report "skipping incompatible file".

As ld manual shows:
If a sysroot prefix is not used then the linker will try to open the file in the directory containing the linker script. If it is not found the linker will then search the current directory. If it is still not found the linker will search through the archive library search path.

[demin-han]

CI failed because of "No space left on device"

[demin-han]

@rui314
linker-script-relocatable.sh failed in all other ISAs.
The reason:
open_library checks machine_type.
resolve_path calls open_library.
get_script_output_type reuses resolve_path in this pr.
deduce_machine_type failed first.

which is the best way to solve this?

1. add check_machine parameter to functions or
2. add check_machine flag to Context

[rui314]

Does the above commit fix the problem for you?

[demin-han]

Does the above commit fix the problem for you?

No, the commit not fix the problem.

get_script_output_type still uses "open" function and open the library existed in current directory.

if (tok.size() >= 3 && (tok[0] == "INPUT" || tok[0] == "GROUP") && tok[1] == "(") if (MappedFile<Context<E>> *mf = MappedFile<Context<E>>::open(ctx, std::string(unquote(tok[2])))) return get_machine_type(ctx, mf);

[rui314]

Can you write a test to demonstrate the issue?

[demin-han]

Can you write a test to demonstrate the issue?

My OS is Manjaro. The minimal requirements as following:

1. the /usr/lib/libgcc_s.so should contains following content:
   /* GNU ld script
   Use the shared library, but some functions are only in
   the static library. */
   GROUP ( libgcc_s.so.1 -lgcc )
2. mkdir test
3. write a test.c in test directory
   int main() {}
4. copy libgcc_s.so.1 of riscv64(or other ISA) to test directory
5. gcc -fuse-lld=mold test.c
6. following error reported:
   mold: warning: /usr/lib/libgcc_s.so: skipping incompatible file riscv64 62
   mold: warning: /lib/libgcc_s.so: skipping incompatible file riscv64 62
   mold: warning: /usr/lib/libgcc_s.so: skipping incompatible file riscv64 62
   mold: warning: /usr/lib//libgcc_s.so: skipping incompatible file riscv64 62
   mold: fatal: library not found: gcc_s

The call trace :
mold::MappedFile<mold::elf::Contextmold::elf::X86_64 >::open(mold::elf::Contextmold::elf::X86_64&,
std::__cxx11::basic_string<char, std::char_traits, std::allocator >)
mold::elf::get_script_output_typemold::elf::X86_64(mold::elf::Contextmold::elf::X86_64&,
mold::MappedFile<mold::elf::Contextmold::elf::X86_64 >)
mold::elf::get_machine_typemold::elf::X86_64(mold::elf::Contextmold::elf::X86_64&,
mold::MappedFile<mold::elf::Contextmold::elf::X86_64 >)
mold::elf::open_librarymold::elf::X86_64(mold::elf::Contextmold::elf::X86_64&, std::__cxx11::basic_string<char,
std::char_traits, std::allocator >)
mold::elf::find_librarymold::elf::X86_64(mold::elf::Contextmold::elf::X86_64&, std::__cxx11::basic_string<char,
std::char_traits, std::allocator >)
mold::elf::read_input_filesmold::elf::X86_64(mold::elf::Contextmold::elf::X86_64&,
std::span<std::__cxx11::basic_string<char, std::char_traits, std::allocator >, 18446744073709551615ul>)
mold::elf::elf_mainmold::elf::X86_64(int, char**)
mold::elf::main(int, char**)
main(int, char**)

[demin-han]

Can you reproduce the problem with the minimal requirement?

[rui314]

I think I understood the issue. I'm preparing a fix.

[rui314]

Can you try again with the above change?

[demin-han]

Can you try again with the above change?

It's OK now.

[rui314]

Cool, thank you for confirming!