It looks like Clang recognize `#pragma GCC unroll`. Instead of adding
more C preprocessor directives here, I'd like to rely on the default
compiler optimizations.
If a synthesized symbol overrides an imported symbol, the symbol's
`is_imported` flag must be reset.
Technically, `compute_import_export` is called too early, and this
function call should be moved after `create_synthetic_sections`.
However, fixing the issue that way was very hard because until we
create output sections, we don't know what __start_/__stop_ symbols
need to be synthesized, but in order to create output sections,
we need to compute import/export bits.
So, in this commit, we simply reset `is_imported` flag for
synthesized symbols.
https://github.com/rui314/mold/pull/1236
Previously, .so and .a were of the same priority and therefore symbols
in those were resolved based on their positions in the command line;
whichever file appears first in the command line took precedence.
Here is the problem we are trying to solve with this change: KiCad
passes unnecessary .a files to the linker along with some .so files.
Some symbols are defined both by .a and by .so.
If a symbol is resolved from .a, the linker pulls out the file from
the archive, but because the .a file does not really provide a
complete set of object files, it ended with "undefined symbol" error.
If a symbol is resolved from .so, everything is fine.
This is arguably a bug in KiCad, or at least depending on the order of
files in the command line is very fragile. But maybe this change could
fix the issue without too much side effects. So let's see how it goes.
Fixes https://github.com/rui314/mold/discussions/1234
