If the C code had variables that were named the same as the prefixes used
for name mangling, such as "tmp" or "ref", then the codegen would generate
incorrect code in some cases. This was because these aliases were immediately
visible to expressions that actually needed to use the original name.
I introduced the concept of reserving aliases without enabling them. An alias
that isn't enabled isn't visible to expression translation, but is still
reserved so that sub-expressions generate aliases that don't overlap.
Add test cases to cover the cases that would break before this change.
Co-authored-by: Veikka Tuominen <git@vexu.eu>
Uses the `atomic.fence` instruction for multi-thread-enabled builds
where the `atomics` feature is enabled for the wasm32 target.
In all other cases, this lowers to a nop.
Implements the lowering of the `@atomicRmw` builtin. Uses the atomic
opcodes when the cpu feature `atomics` is enabled. Otherwise lowers
it to regular instructions. For the operations that do not lower to
a direct atomic opcode, we use a loop in combiantion with a cmpxchg
to ensure the swapping of values is doing atomically.
When the user passes the cpu feature `atomics` to the target triple,
the backend will lower the AIR instruction using opcodes from the
atomics feature instead of manually lowering it.
Often, a `dbg_stmt` ends up being associated with no real code because
whatever it referred to was eliminated by semantic analysis. In these
cases, Sema can replace the last `dbg_stmt` with the new one to avoid
redundant AIR instructions which at best are nops and at worst cause
backends to emit useless info (e.g. CBE does this).
to avoid getting OOM killed. We need to have a high number of GitHub
Actions runners simultaneously active, otherwise the hardware ends up
underutilized. But with zig build running in parallel now, this
sometimes results in memory usage spikes that have been causing the
runner to get killed.
This number is the total physical memory (251G) divided by the number of
runners we have active (11).
See related commit 2d41dac57d3afdd5fe3d03be08ff0a24833f61dd which did
the same but for our x86_64-linux machines.
Pointer comparisons were triggering `-Wcompare-distinct-pointer-types`
before this fix, which adds `(void*)` casts if the lhs type and rhs type
do not match pointer sizeness.
store:
The value to store may be undefined, in which case the destination
memory region has undefined bytes after this instruction is
evaluated. In such case ignoring this instruction is legal
lowering.
store_safe:
Same as `store`, except if the value to store is undefined, the
memory region should be filled with 0xaa bytes, and any other
safety metadata such as Valgrind integrations should be notified of
this memory region being undefined.
Needed due to the compiler depending on standard library APIs such as
ArrayList that contain `@memset` and `@memcpy` calls in them. The number
of parameters changed, so this is necessary for the compiler to build.
Previously, this code casted the array pointer to u8 pointer, but I
removed that in a different commit. This commit restores the cast, but
instead of hard-coding u8, it uses the destination element pointer,
since memset now supports arbitrary element types.
* Sema: upgrade operands to array pointers if possible when emitting
AIR.
* Implement safety checks for length mismatch and aliasing.
* AIR: make ptrtoint support slice operands. Implement in LLVM backend.
* C backend: implement new `@memset` semantics. `@memcpy` is not done
yet.
Now they use slices or array pointers with any element type instead of
requiring byte pointers.
This is a breaking enhancement to the language.
The safety check for overlapping pointers will be implemented in a
future commit.
closes#14040
addition to #15450
createFileW does not account for failure on `LockFile`. This can result
in a file handle not being closed on failure which can be seen on test
such as `fs.test.'open file with exclusive nonblocking lock twice'`.
