This allows the `acid` debugger on
plan9 to be used to debug a zig source
file without patching `acid`!
The patch adds a second `z` symbol. This z
symbol has a value of 0, which means that it
pops the history stack. We put a very large
number for the value of the second symbol because
it has to be at least as large as the linecount of
the file. The debuginfo format is meant to be used
with c files, where the stack would look something
like this:
```
-> Line: 0x1 (1) Name: 0x1/0x2/0x3/0xe/0x13/0x1b (/sys/src/libc/port/malloc.c)
-> Line: 0x2 (2) Name: 0x1/0x6/0x7/0x8 (/amd64/include/u.h)
-> Line: 0x4f (79) Name: ()
-> Line: 0x50 (80) Name: 0x1/0x2/0x7/0x9 (/sys/include/libc.h)
-> Line: 0x358 (856) Name: ()
-> Line: 0x359 (857) Name: 0x1/0x2/0x7/0x1c (/sys/include/pool.h)
-> Line: 0x392 (914) Name: ()
-> Line: 0x393 (915) Name: 0x1/0x2/0x7/0x1d (/sys/include/tos.h)
-> Line: 0x3ab (939) Name: ()
-> Line: 0x4eb (1259) Name: ()
```
however in zig, we do not use includes and .h files,
so we only need the first and last items in the stack:
the source file that the symbols belong to, and the pop
symbol with a null name and a value of the total linecount of the
preprocessed source. Since there is no preprocessing in zig, we
just make the linecount very large. There do not appear to be
any downsides to this approach. If this causes a bug in the future,
a simple fix would be to make the pop symbol just have the value
of how many newlines are in the source file.
const locals now detect if the value ends up being comptime known. In
such case, it replaces the runtime AIR instructions with a decl_ref
const.
In the backends, some more sophisticated logic for marking decls as
alive was needed to prevent Decls incorrectly being garbage collected
that were indirectly referenced in such manner.
Add a variant of the `validate_struct_init` ZIR instruction:
`validate_struct_init_comptime` which is the same thing except it
indicates a comptime scope.
Sema code for this instruction now handles default struct field
values and detects when the struct initialization resulted in a
comptime value, replacing the already-emitted AIR instructions
to store each individual field with a single `store` instruction
with a comptime struct value as the operand.
In the case of a comptime scope, there is a simpler path that only
evals the implicit store instructions for default field values, avoiding
the mechanism for detecting comptime values.
This regressed one test case for the wasm backend, but it's just hitting
a different prong of `emitConstant` which currently has "TODO" in there,
so I think it's fine.
This allows Zig code to perform conditional compilation based on a tag
by which a Zig compiler implementation identifies itself.
See the doc comment in this commit for more details.
We now detect if the return type will be set by passing the first argument
as a pointer to stack memory from the callee's frame. This way, we do not have to
worry about stack memory being overwritten.
Besides this, we implement memset by either using wasm's memory.fill instruction when available,
or lower it manually. In the future we can lower this to a compiler_rt call.
Previously we were performing the wrapping and unwrapping operations incorrectly.
We now correctly create the type and set its values.
Besides this, we also set the null-byte to the incorrect value, which meant we were
doing the opposite action of a is_null check. This is now fixed as well.
While implementing this, I found a small bug in the wrapErrUnionPayload where we
would load a pointer value and save that, rather than store the pointer with the error.
This is now fixed as well, by copying the entire operand into the payload of the error union.
copy_cqes() is not guaranteed to return as many CQEs as provided in the
`wait_nr` argument, meaning the assert in `copy_cqe` can trigger.
Instead, loop until we do get at least one CQE returned.
This mimics the behaviour of liburing's _io_uring_get_cqe.
This commit fixes two problems:
* `zig build-obj` regressed from the cache-mode branch. It would crash
because it assumed that dirname on the emit bin path would not be
null. This assumption was invalid when outputting to the current
working directory - a pretty common use case for `zig build-obj`.
* When using the LLVM backend, `-fno-emit-bin` combined with any other
kind of emitting, such as `-femit-asm`, emitted nothing.
Both issues are now fixed.
