`testing.expect` is better than `testing.expectEqual` for behavior
tests. Better for behavior tests to stick to only testing the limited
behavior they are meant to test and avoid functions such as
`expectEqual` that drag in too much of the standard library (in this
case to print helpful diffs about why a value is not equal to another).
Adds the sentinel element to the type name to avoid ambiguous
declarations, and outputs the sentinel element (if needed) even in what
would otherwise be empty arrays.
I think that reusing the ComptimePtrLoad infrastructure is ultimately
less logic and more robust than adding a `direct` flag to elem_ptr.
* Some code in zirTypeInfo needed to be fixed to create proper
Type/Value encodings.
* comptime elemVal works by constructing an elem_ptr Value and then
using the already existing pointerDeref function.
There are some remaining calls to Value.elemValue which should be
considered code smells at this point.
This fixes one of the major issues plaguing the `std.sort` comptime tests.
The high level issue is that at comptime, we need to know whether `elem_ptr` is
being used to subslice an array-like pointer or access a child value. High-level
example:
var x: [2][2]i32 = undefined;
var a = &x[0]; // elem_ptr, type *[2]i32
var y: [5]i32 = undefined;
var b = y[1..3]; // elem_ptr, type *[2]i32
`a` is pointing directly to the 0th element of `x`. But `b` is
subslicing the 1st and 2nd element of `y`. At runtime with a well
defined memory layout, this is an inconsequential detail. At comptime,
the values aren't laid out exactly in-memory so we need to know the
difference.
This becomes an issue specifically in this case:
var c: []i32 = a;
var d: []i32 = b;
When converting the `*[N]T` to `[]T` we need to know what array to point
to. For runtime, its all the same. For comptime, we need to know if its
the parent array or the child value.
See the behavior tests for more details.
This commit fixes this by adding a boolean to track this on the
`elem_ptr`. We can't just immediately deref the child for `&x[0]`
because it is legal to ptrCast it to a many-pointer, do arithmetic, and
then cast it back (see behavior test) so we need to retain access to the
"parent" indexable.
Currently, the new API will only be available on macOS with
the intention of adding more POSIX systems to it incrementally
(such as Linux, etc.).
Changes:
* add `posix_spawn` wrappers in a separate container in
`os/posix_spawn.zig`
* rewrite `ChildProcess.spawnPosix` using `posix_spawn` targeting macOS
as `ChildProcess.spawnMacos`
* introduce a `posix_spawn` specific `std.c.waitpid` wrapper which
does return an error in case the child process failed to exec - this
is required for any process that was spawned using `posix_spawn`
mechanism as, by definition, the errors returned by `posix_spawn`
routine cover only the `fork`-equivalent; `pre-exec()` and `exec()`
steps are covered by a catch-all error `ECHILD` returned by `waitpid`
on unsuccessful execution, e.g., no such file error, etc.
This involved some significant reworking in order to introduce the
concept of "forward declarations" to the system to break dependency
loops.
The `lowerDebugType` function now takes an `enum { full, fwd }` and is moved
from `DeclGen` to `Object` so that it can be called from `flushModule`.
`DITypeMap` is now an `ArrayHashMap` instead of a `HashMap` so that we can
iterate over the entries in `flushModule` and finalize the forward decl
DITypes into full DITypes.
`DITypeMap` now stores `AnnotatedDITypePtr` values instead of
`*DIType` values. This is an abstraction around a `usize` which assumes
the pointers will be at least 2 bytes aligned and uses the least
significant bit to store whether it is forward decl or a fully resolved
debug info type.
`lowerDebugTypeImpl` is extracted out from `lowerDebugType` and it has a
mechanism for completing a forward decl DIType to a fully resolved one.
The function now contains lowering for struct types. Closes#11095.
There is a workaround for struct types which have not had
`resolveFieldTypes` called in Sema, even by the time `flushModule` is
called. This is a deficiency of Sema that should be addressed, and the
workaround removed. I think Sema needs a new mechanism to queue up type
resolution work instead of doing it in-line, so that it does not cause
false dependency loops. We already have one failing behavior test
because of a false dependency loop.
Prior to these, the return type was non-null but the value was generic
poison which wasn't usable in user-space. This sets the value to null.
This also adds a behavior test for this.
Co-authored-by: InKryption <inkryption07@gmail.com>
This resolves https://github.com/ziglang/zig/issues/11159
The problem was that:
1. We were not correctly deleting the field stores after recognizing
that an array initializer was a comptime-known value.
2. LLVM was not checking that the final type had no runtime bits, and
so would generate an invalid store.
This also adds several test cases for related bugs, just to check these
in for later work.
We must resolve the type fully so that pointer children (i.e. slices)
are resolved. Additionally, we must resolve even if we can know the
value at comptime because the `alloc_inferred` ZIR always produces a
constant in the AIR.
Fixes#11181
A const local which had its init expression write to the result pointer,
but then gets elided to directly initialize, was missing the coercion to
the type annotation.
DWARF 5 moves around some fields and adds a few new ones that can't be
parsed or ignored by our current DWARF 4 parser. This isn't a complete
implementation of DWARF 5, but this is enough to make stack traces
mostly work. Line numbers from C++ don't show up, but I know the info
is there. I think the answer is to iterate through .debug_line_str in
getLineNumberInfo, but I didn't want to fall into an even deeper rabbit
hole tonight.
Compilers will sometimes `#define linux 1` if the operating system in
use is Linux. This clashes with the code produced by the C backend when
processing the stdlib, e.g. std.Target.Os.VersionRange [^1] which is a
struct containing a field named `linux`.
The output of the C backend doesn't rely on this macro being defined,
and other code also shouldn't rely on it -- e.g. quoting from the GCC
documentation [^2]:
"""
The C standard requires that all system-specific macros be part of
the reserved namespace. All names which begin with two underscores, or
an underscore and a capital letter, are reserved for the compiler and
library to use as they wish. However, historically system-specific
macros have had names with no special prefix; for instance, it is
common to find unix defined on Unix systems.
[...]
We are slowly phasing out all predefined macros which are outside the
reserved namespace. You should never use them in new programs, and we
encourage you to correct older code to use the parallel macros
whenever you find it. We don’t recommend you use the system-specific
macros that are in the reserved namespace, either. It is better in the
long run to check specifically for features you need
"""
[^1]: 8c32d989c9/lib/std/target.zig (L224)
[^2]: https://gcc.gnu.org/onlinedocs/cpp/System-specific-Predefined-Macros.html#System-specific-Predefined-Macros
target.Arch already supports finding the correct encoding for either
target, so being able to do the inverse has use cases for when parsing
files of an unknown target (i.e. for zar).
* don't store `has_well_defined_layout` in memory.
* remove struct `hasWellDefinedLayout` logic. it's just
`layout != .Auto`. This means we only need one implementation, in
Type.
* fix some of the cases being wrong in `hasWellDefinedLayout`, such as
optional pointers.
* move `tag_ty_inferred` field into a position that makes it more
obvious how the struct layout will be done. Also we don't have a
compiler that intelligently moves fields around so this layout is
better.
* Sema: don't `resolveTypeLayout` in `zirCoerceResultPtr` unless
necessary.
* Rename `ComptimePtrLoadKit` `target` field to `pointee` to avoid
confusion with `target`.
We need to make sure that we bitcast our pointers correctly before
we use get_element_ptr to compute the offset for the parent
pointer.
This also includes a small fix-up for a problem where ptrs to const
i64/u64 were not using the correct type in >1-level decl chains
(where we call lowerParentPtr recursively)
The core change here is that we no longer blindly trust that parent
pointers (.elem_ptr, .field_ptr, .eu_payload_ptr, .union_payload_ptr)
were derived from the "true" type of the underlying decl. When types
diverge, direct dereference fails and we are forced to bitcast, as
usual.
In order to maximize our chances to have a successful bitcast, this
includes several changes to the dereference procedure:
- `root` is now `parent` and is the largest Value containing the
dereference target, with the condition that its layout and the
byte offset of the target within are both well-defined.
- If the target cannot be dereferenced directly, because the
pointers were not derived from the true type of the underlying
decl, then it is returned as null.
- `beginComptimePtrDeref` now accepts an optional array_ty param,
which is used to directly dereference an array from an elem_ptr,
if necessary. This allows us to dereference array types without
well-defined layouts (e.g. `[N]?u8`) at an offset
The load_ty also allows us to correctly "over-read" an .elem_ptr to an
array of [N]T, if necessary. This makes direct dereference work for
array types even in the presence of an offset, which is necessary if
the array has no well-defined layout (e.g. loading from `[6]?u8`)
