Prior to this change the clang interface stubs format resembled
something ending with a symbol list like this:
Symbols:
a: { Type: Func }
This was problematic because we didn't actually want a map format and
also because we didn't like that an empty symbol list required
"Symbols: {}". That is to say without the empty {} llvm-ifs would crash
on an empty list.
With this new format it is much more clear which field is the symbol
name, and instead the [] that is used to express an empty symbol vector
is optional, ie:
Symbols:
- { Name: a, Type: Func }
or
Symbols: []
or
Symbols:
This further diverges the format from existing llvm-elftapi. This is a
good thing because although the format originally came from the same
place, they are not the same in any way.
Differential Revision: https://reviews.llvm.org/D76979
Third Landing Attempt (dropping any linker invocation from clang driver):
Up until now, clang interface stubs has replaced the standard
PP -> C -> BE -> ASM -> LNK pipeline. With this change, it will happen in
conjunction with it. So what when you build your code you will get an
a.out or lib.so as well as an interface stub file.
Example:
clang -shared -o libfoo.so -emit-interface-stubs ...
will generate both a libfoo.so and a libfoo.ifso. The .so file will
contain the code from the standard compilation pipeline and the .ifso
file will contain the ELF stub library.
Note: For driver-test.c I've added -S in order to prevent any bot failures on
bots that don't have the proper linker for their native triple. You could always
specify a triple like x86_64-unknown-linux-gnu and on bots like x86_64-scei-ps4
the clang driver would invoke regular ld instead of getting the error
'Executable "orbis-ld" doesn't exist!' but on bots like ppc64be and s390x you'd
get an error "/usr/bin/ld: unrecognised emulation mode: elf_x86_64"
Differential Revision: https://reviews.llvm.org/D70274
Second Landing Attempt:
Up until now, clang interface stubs has replaced the standard
PP -> C -> BE -> ASM -> LNK pipeline. With this change, it will happen in
conjunction with it. So what when you build your code you will get an
a.out or lib.so as well as an interface stub file.
Example:
clang -shared -o libfoo.so -emit-interface-stubs ...
will generate both a libfoo.so and a libfoo.ifso. The .so file will
contain the code from the standard compilation pipeline and the .ifso
file will contain the ELF stub library.
Differential Revision: https://reviews.llvm.org/D70274
Puyan Lotfi