- Add default values to the list of comptime-known elements in
`zirValidatePtrArrayInit`
- In `structFieldValueComptime`, only assert `haveFieldInits` if we
enter the`fieldIsComptime` branch (otherwise they are not needed).
Before this fix, passing an undefined union value to `Sema.switchCond`
returned an undefined value of the union type, not the tag type, since
`Value.unionTag` forwards undefined values unchanged.
This leads us into the `.Union` branch in `Sema.zirSwitchBlock` which is
unreachable, now we take the `.Enum` branch instead.
The generic call `S.foo()` was evaluated with the
capture scope of the owner decl (i.e the `test` block), when it should
use the capture scope of the function declaration.
This commit eliminates the `dbg_block_{begin,end}` instructions from
both ZIR and AIR. Instead, lexical scoping of `dbg_var_{ptr,val}`
instructions is decided based on the AIR block they exist within. This
is a much more robust system, and also results in a huge drop in ZIR
bytes - around 7% for Sema.zig.
This required some enhancements to Sema to prevent elision of blocks
when they are required for debug variable scoping. This can be observed
by looking at the AIR for the following simple test program with and
without `-fstrip`:
```zig
export fn f() void {
{
var a: u32 = 0;
_ = &a;
}
{
var a: u32 = 0;
_ = &a;
}
}
```
When `-fstrip` is passed, no AIR blocks are generated. When `-fno-strip`
is passed, the ZIR blocks are lowered to true AIR blocks to give correct
lexical scoping to the debug vars.
The changes here incidentally reolve #19060. A corresponding behavior
test has been added.
Resolves: #19060
* make test names contain the fully qualified name
* make test filters match the fully qualified name
* allow multiple test filters, where a test is skipped if it does not
match any of the specified filters
Similar to the previous commit, errors coercing the panic message to
`[]const u8` now point at the operand to `@panic` rather than the actual
builtin call.
When coercing the operand of a `ret_node` etc instruction, the source
location for errors used to point to the entire `return` statement.
Instead, we now point to the operand, as would be expected if there was
an explicit `as_node` instruction (like there used to be).
Previously, the `src_node` field of `struct_decl`, `union_decl`,
`enum_decl`, and `opaque_decl` was optional, included in trailing data
only if a flag in `Small` was set. However, this was unnecessary logic:
AstGen always provided the source node. We can simplify a few bits of
logic by making this field non-optional, moving it into non-trailing
data.
There was one place where the field was actually omitted before: the
root struct of a file was at source node 0, so the node was
coincidentally elided. Therefore, this commit has a fixed cost of 4
bytes of ZIR per file.
In most cases where AstGen is coercing to a fixed type (such as `u29`,
`type`, `std.builtin.CallingConvention) we do not necessarily require an
explicit coercion instruction. Instead, Sema knows the type that is
required, and can perform the coercion after the fact. This means we can
use the `coerced_ty` result location kind, saving unnecessary coercion
instructions and therefore ZIR bytes.
This required a few enhancements to Sema to introduce missing coercions.
`sema.src` is a failed experiment. It introduces complexity, and makes
often unwarranted assumptions about the existence of instructions
providing source locations, requiring an unreasonable amount of caution
in AstGen for correctness. Eliminating it simplifies the whole frontend.
This required adding source locations to a few instructions, but the
cost in ZIR bytes should be counteracted by the other work on this
branch.
This logic (currently) has a non-trivial cost (particularly in terms of
peak RSS) for tracking dependencies. Until incremental compilation is in
use in the wild, it doesn't make sense for users to pay that cost.
* Functions failing codegen now set this failure on the function
analysis state. Decl analysis `codegen_failure` is reserved for
failures generating constant values.
* `liveness_failure` is consolidated into `codegen_failure`, as we do
not need to distinguish these, and Liveness.Verify is just a debugging
feature anyway.
* `sema_failure_retryable` and `codegen_failure_retryable` are removed.
Instead, retryable failures are recorded in the new
`Zcu.retryable_failures` list. On an incremental update, this list is
flushed, and all elements are marked as outdated so that we re-attempt
analysis and code generation.
Also remove the `generation` fields from `Zcu` and `Decl` as these are
not needed by our new strategy for incremental updates.
Sema now tracks dependencies appropriately. Early logic in Zcu for
resolving outdated decls/functions is in place. The setup used does not
support `usingnamespace`; compilations using this construct are not yet
supported by this incremental compilation model.
It is problematic for the cached `InternPool` state to directly
reference ZIR instruction indices, as these are not stable across
incremental updates. The existing ZIR mapping logic attempts to handle
this by iterating the existing Decl graph for a file after `AstGen` and
update ZIR indices on `Decl`s, struct types, etc. However, this is
unreliable due to generic instantiations, and relies on specialized
logic for everything which may refer to a ZIR instruction (e.g. a
struct's owner decl). I therefore determined that a prerequisite change
for incremental compilation would be to rework how we store these
indices.
This commit introduces a `TrackedInst` type which provides a stable
index (`TrackedInst.Index`) for a single ZIR instruction in the
compilation. The `InternPool` now stores these values in place of ZIR
instruction indices. This makes the ZIR mapping logic relatively
trivial: after `AstGen` completes, we simply iterate all `TrackedInst`
values and update those indices which have changed. In future, if the
corresponding ZIR instruction has been removed, we must also invalidate
any dependencies on this instruction to trigger any required
re-analysis, however the dependency system does not yet exist.
This commit changes how declarations (`const`, `fn`, `usingnamespace`,
etc) are represented in ZIR. Previously, these were represented in the
container type's extra data (e.g. as trailing data on a `struct_decl`).
However, this introduced the complexity of the ZIR mapping logic having
to also correlate some ZIR extra data indices. That isn't really a
problem today, but it's tricky for the introduction of `TrackedInst` in
the commit following this one. Instead, these type declarations now
simply contain a trailing list of ZIR indices to `declaration`
instructions, which directly encode all data related to the declaration
(including containing the declaration's body). Additionally, the ZIR for
`align` etc have been split out into their own bodies. This is not
strictly necessary, but it's much simpler to understand for an
insignificant cost in bytes, and will simplify the resolution of #131
(where we may need to evaluate the pointer type, including align etc,
without immediately evaluating the value body).
During semantic analysis the value may be an unresolved lazy value
which makes using `toUnsignedInt` invalid.
Add assertions to detect similar issues in the future.
Closes#18624
This logic was previously in Sema, which was unnecessary complexity, and meant the issue was not detected unless the declaration was semantically analyzed. This commit finishes the work which 941090d started.
Resolves: #17916
