No longer automatically append the `--export` flag for each exported
function unconditionally. This was essentially a hack to prevent
binary bloat caused by compiler-rt symbols being always included in
the final binary as they were exported and therefore not garbage-
collected. This is no longer needed as we now support the ability to
set the visibility of exports.
This essentially reverts 6d951aff7e32b1b0252d341e66517a9a9ee98a2d
`-undefined dynamic_lookup` was added in #13991. `-undefined error` is the
opposite, and can be used to revert an `-undefined dynamic_lookup` flag
specified previously on the command line.
When using llvm opaque pointers, typed pointers and pointer bitcasts are
no longer needed. This also avoids needing packed struct layouts that
are nested inside pointers, letting us avoid computing struct layouts
in Sema that could cause unnecessary dependency loops.
In #1622, when targeting WebAsembly, the --allow-undefined flag
became unconditionally added to the linker.
This is not always desirable.
First, this is error prone. Code with references to unkown symbols
will link just fine, but then fail at run-time.
This behavior is inconsistent with all other targets.
For freestanding wasm applications, and applications that only use
WASI, undefined references are better reported at compile-time.
This behavior is also inconsistent with clang itself. Autoconf and
cmake scripts checking for function presence think that all tested
functions exist, but then resulting application cannot run.
For example, this is one of the reasons compilation of Ruby 3.2.0
to WASI fails with zig cc, while it works out of the box with clang.
But all applications checking for symbol existence before compilation
are affected.
This reverts the behavior to the one Zig had before #1622, and
introduces an `import_symbols` flag to ignore undefined symbols,
assuming that the webassembly runtime will define them.
Otherwise, we were prematurely committing `__LINKEDIT` segment LC
with outdated size (i.e., without code signature being taken into account).
This would scaffold into strict validation failures by Apple tooling.
The extended instructions starting with opcode `0xFC` are refactored
to make the work the same as the SIMD instructions. This means a
`Mir` instruction no longer contains a field 'secondary'. Instead,
we use the `payload` field to store the index into the extra list
which contains the extended opcode value. In case of instructions
such as 'memory.fill' which also have an immediate value, such
values will also be stored in the extra list right after the
instruction itself. This makes each `Mir` instruction smaller.
