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`)
This follows the same strategy as sema.typeRequiresComptime() and
type.comptimeOnly(): Two versions of the function, one which performs
resolution just-in-time and another which asserts that resolution is
complete.
Thankfully, this doesn't cause very viral type resolution, since
auto-layout structs and unions are very common and are known to not have
a well-defined layout without resolving their fields.
LLVM backend: generate DIGlobalVariable's for non-function globals and
rename linkage names when exporting functions and globals.
zig_llvm.cpp: add some wrappers to convert a handful of DI classes
into DINode's since DIGlobalVariable is not a DIScope like the others.
zig_llvm.cpp: add some wrappers to allow replacing the LinkageName of
DISubprogram and DIGlobalVariable.
zig_llvm.cpp: fix DI class mixup causing nonsense reinterpret_cast.
The end result is that GDB is now usable since you now no longer need
to manually cast every global nor fully qualify every export.
It is possible for the value length to be longer than the type because
we allow in-memory coercing of types such as `[5:0]u8` to `[5]u8`. In
such a case, the value length is 6 but the type length if 5.
The `.repeated` value type already got this right, so this is extending
similar logic out to `.aggregate` and `.bytes`. Both scenarios are
tested in behavior tests.
Fixes#11165
This also surfaces the fact that clz, ctz and popCount didn't actually
support 128 bit integers, despite what was claimed by
226fcd7c709ec664c5d883042cf7beb3026f66cb. This was partially hidden by
the fact that the test code for popCount only exercised 128 bit integers
in a comptime context. This commit duplicates that test case for runtime
ints too.
Implements `@Type` for structs, anon structs, and tuples. This is another place that would probably benefit from a `.reified_struct` type tag but will defer for later in the interest of getting tests passing first.
Detect if we are storing an array operand to a bitcasted vector pointer.
If so, we instead reach through the bitcasted pointer to the vector pointer,
bitcast the array operand to a vector, and then lower this as a store of
a vector value to a vector pointer. This generally results in better code,
as well as working around an LLVM bug.
See #11154
This parameter is only currently needed by zig_byte_swap() and
zig_bit_reverse(). This commit adds an option to airBuiltinCall() to
allow emitting the signedness information only when needed, removing
this unused parameter from the other builtins.
