A pointer type already has an alignment, so this information does not
need to be duplicated on the function type. This already has precedence
with addrspace which is already disallowed on function types for this
reason. Also fixes `@TypeOf(&func)` to have the correct addrspace and
alignment.
This fixes a bug where, at least with the LLVM backend, `@extern` calls
which had the same name as a normal `extern` in the same Zcu would
result in the `@extern` incorrectly suffixing the identifier `.2`.
Usually, the LLVM backend has a system to change the generated globals
to "collapse" them all together, but it only works if `updateDecl` is
called!
Previously, when multiple modules had builtin modules with identical
sources, two distinct `Module`s and `File`s were created pointing at the
same file path. This led to a bug later in the frontend. These modules
are now deduplicated with a simple hashmap on the builtin source.
This fixes an issue with the implementation of #18816. Consider the
following code:
```zig
pub fn Wrap(comptime T: type) type {
return struct {
pub const T1 = T;
inner: struct { x: T1 },
};
}
```
Previously, the type of `inner` was not considered to be "capturing" any
value, as `T1` is a decl. However, since it is declared within a generic
function, this decl reference depends on the context, and thus should be
treated as a capture.
AstGen has been augmented to tunnel references to decls through closure
when the decl was declared in a potentially-generic context (i.e. within
a function).
This implements the accepted proposal #18816. Namespace-owning types
(struct, enum, union, opaque) are no longer unique whenever analysed;
instead, their identity is determined based on their AST node and the
set of values they capture.
Reified types (`@Type`) are deduplicated based on the structure of the
type created. For instance, if two structs are created by the same
reification with identical fields, layout, etc, they will be the same
type.
This commit does not produce a working compiler; the next commit, adding
captures for decl references, is necessary. It felt appropriate to split
this up.
Resolves: #18816
Namespace types (`struct`, `enum`, `union`, `opaque`) do not use
structural equality - equivalence is based on their Decl index (and soon
will change to AST node + captures). However, we previously stored all
other information in the corresponding `InternPool.Key` anyway. For
logical consistency, it makes sense to have the key only be the true key
(that is, the Decl index) and to load all other data through another
function. This introduces those functions, by the name of
`loadStructType` etc. It's a big diff, but most of it is no-brainer
changes.
In future, it might be nice to eliminate a bunch of the loaded state in
favour of accessor functions on the `LoadedXyzType` types (like how we
have `LoadedUnionType.size()`), but that can be explored at a later
date.
This changes the representation of closures in Zir and Sema. Rather than
a pair of instructions `closure_capture` and `closure_get`, the system
now works as follows:
* Each ZIR type declaration (`struct_decl` etc) contains a list of
captures in the form of ZIR indices (or, for efficiency, direct
references to parent captures). This is an ordered list; indexes into
it are used to refer to captured values.
* The `extended(closure_get)` ZIR instruction refers to a value in this
list via a 16-bit index (limiting this index to 16 bits allows us to
store this in `extended`).
* `Module.Namespace` has a new field `captures` which contains the list
of values captured in a given namespace. This is initialized based on
the ZIR capture list whenever a type declaration is analyzed.
This change eliminates `CaptureScope` from semantic analysis, which is a
nice simplification; but the main motivation here is that this change is
a prerequisite for #18816.
* Introduce `-Ddebug-extensions` for enabling compiler debug helpers
* Replace safety mode checks with `std.debug.runtime_safety`
* Replace debugger helper checks with `!builtin.strip_debug_info`
Sometimes, you just have to debug optimized compilers...
Since we now elide more ZIR blocks in AstGen, care must be taken in
codegen to introduce lexical scopes for every body, not just `block`s.
Also, elide a few unnecessary AIR blocks in Sema.
The signature and variants of Sema's main loop have evolved over time to
what was a quite confusing state of affairs. This commit makes minor
changes to how `analyzeBodyInner` works, and restructures/renames the
wrapper functions, adding doc comments to clarify their purposes. The
most notable change is that `analyzeBodyInner` now returns
`CompileError!void`; inline breaks are now all communicated via
`error.ComptimeBreak`.
- 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.
