```
$ cat overflow.zig
test {
var a: [1]u65535 = undefined;
_ = a;
}
$ zig-out/bin/zig test overflow.zig
thread 290266 panic: integer overflow
zig/src/type.zig:3604:55: 0xada43d in intAbiAlignment (zig)
std.math.ceilPowerOfTwoPromote(u16, (bits + 7) / 8),
^
zig/src/type.zig:3598:42: 0xadd4ea in intAbiSize (zig)
const alignment = intAbiAlignment(bits, target);
^
zig/src/type.zig:3500:61: 0x92be91 in abiSizeAdvanced (zig)
return AbiSizeAdvanced{ .scalar = intAbiSize(bits, target) };
^
zig/src/type.zig:3385:62: 0x928933 in abiSizeAdvanced (zig)
switch (try payload.elem_type.abiSizeAdvanced(target, strat)) {
^
zig/src/type.zig:3268:32: 0x92c012 in abiSize (zig)
return (abiSizeAdvanced(ty, target, .eager) catch unreachable).scalar;
^
```
This is only noticed in a debug build of zig and silently does the wrong
thing and overflows in release builds.
This happened to `[x]u65529` and above because of the ` + 7` on a `u16`.
Fixes#15489
This also lays the groundwork for exposing the whether or not a function is
noinline in std.builtin.Fn as an `is_noinline: bool` field if we ever want to do that.
* 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.
AmdgpuKernel and NvptxKernel are unified into a Kernel calling convention.
There is really no reason for these to be separate; no backend is allowed to
emit the calling convention of the other. This is in the same spirit as the
.Interrupt calling convention lowering to different LLVM calling conventions,
and opens the way for SPIR-V kernels to be exported using the Kernel calling
convention.
This also makes another breaking change to for loops: in order to
capture a pointer of an element, one must take the address of array
values. This simplifies a lot of things, and makes more sense than how
it was before semantically.
It is still legal to use a for loop on an array value if the
corresponding element capture is byval instead of byref.
There are still a few occurrences of "stage1" in the standard library
and self-hosted compiler source, however, these instances need a bit
more careful inspection to ensure no breakage.
I wasn't able to create a reduced test case for this but the reasoning
can be seen in `abiAlignmentAdvancedUnion` where if `strat` was lazy
`hasRuntimeBitsAdvanced` would be given `null` instead of `sema`
which would cause eager evaluation when it is not valid or desired.
These parameters are only ever needed when `std.builtin` is out of sync
with the compiler in which case panicking is the only valid operation
anyways. Removing them causes a domino effect of functions no longer
needing a `src` and/or a `block` parameter resulting in handling
compilation errors where they are actually meaningful becoming simpler.
These functions have a very error-prone API. They are essentially
`all(cmp(op, ...))` but that's not reflected in the name.
This renames these functions to `compareAllAgainstZero...` etc.
for clarity and fixes >20 locations where the predicate was
incorrect.
In the future, the scalar `compare` should probably be split off
from the vector comparison. Rank-polymorphic programming is great,
but a proper implementation in Zig would decouple comparison and
reduction, which then needs a way to fuse ops at comptime.
On platforms where c_longdouble is 128-bits, interop with C code
is simplified by making f128 match the alignment of c_longdouble.
I intended to make this change as part of #13257, but I missed this
part.
