* New AIR instruction: slice, which constructs a slice out of a pointer
and a length.
* AstGen: use `coerced_ty` for start and end expressions, use `none`
for the sentinel, and don't try to load the result of the slice
operation because it returns a by-value result.
* Sema: pointer arithmetic is extracted into analyzePointerArithmetic
and it is used by the implementation of slice.
- Also I implemented comptime pointer addition.
* Sema: extract logic into analyzeSlicePtr, analyzeSliceLen and use them
inside the slice semantic analysis.
- The approach in stage2 is much cleaner than stage1 because it uses
more granular analysis calls for obtaining the slice pointer, doing
arithmetic on it, and checking if the length is comptime-known.
* Sema: use the slice Value Tag for slices when doing coercion from
pointer-to-array.
* LLVM backend: detect when emitting a GEP instruction into a
pointer-to-array and add the extra index that is required.
* Type: ptrAlignment for c_void returns 0.
* Implement Value.hash and Value.eql for slices.
* Remove accidentally duplicated behavior test.
* AstGen: Move `refToIndex` and `indexToRef` to Zir
* ZIR: the switch_block_*_* instruction tags are collapsed into one
switch_block tag which uses 4 bits for flags, and reduces the
scalar_cases_len field from 32 to 28 bits.
This freed up more ZIR tags, 2 of which are now used for
`switch_cond` and `switch_cond_ref` for producing the switch
condition value. For example, for union values it returns the
corresponding enum value.
* switching with multiple cases and ranges is not yet supported because
I want to change the ZIR encoding to store index pointers into the
extra array rather than storing prong indexes. This will avoid O(N^2)
iteration over prongs.
* AstGen now adds a `switch_cond` on the operand and then passes the
result of that to the `switch_block` instruction.
* Sema: partially implement `switch_capture_*` instructions.
* Sema: `unionToTag` notices if the enum type has only one possible value.
Dereferencing single pointers is now handled outside of the main switch,
which allows deduplication of some cases. This also implements the
relevant operations for pointers to types and pointers to slices.
When returning an error set or an error union from a function which has
an inferred error set, it populates the error names in addition to the
set of functions. This can have false negatives, meaning that after
checking the map of an unresolved error set, one must do full error set
resolution before emitting a compile error.
* Sema: fix returned operands not coercing to the function return type
in some cases.
- When returning an error or an error union from a function with an
inferred error set, it will now populate the inferred error set.
- Implement error set coercion for the common case of inferred error
set to inferred error set, without forcing a full resolution.
* LLVM backend: update instruction lowering that handles error unions
to respect `isByRef`.
- Also implement `wrap_err_union_err`.
* Relax compile error for "unable to export type foo" to allow
integers, structs, arrays, and floats. This will need to be further
improved to do the same checks as we do for C ABI struct field types.
* LLVM backend: fix extern variables
* LLVM backend: implement AIR instruction `wrap_err_union_payload`
* Sema: implement peer type resolution for optionals and null.
* Rename `Module.optionalType` to `Type.optional`.
* LLVM backend: re-use anonymous values. This is especially useful when
isByRef()=true because it means re-using the same generated LLVM globals.
* LLVM backend: rework the implementation of is_null and is_non_null
AIR instructions. Generate slightly better LLVM code, and also fix
the behavior for optionals whose payload type is 0-bit.
* LLVM backend: improve `cmp` AIR instruction lowering to support
pointer-like optionals.
* `Value`: implement support for equality-checking optionals.
* std.os: take advantage of `@minimum`. It's probably time to
deprecate `std.min` and `std.max`.
* New AIR instructions: min and max
* Introduce SIMD vector support to stage2
* Add `@Type` support for vectors
* Sema: add `checkSimdBinOp` which can be re-used for other arithmatic
operators that want to support vectors.
* Implement coercion from vectors to arrays.
- In backends this is handled with bitcast for vector to array,
however maybe we want to reduce the amount of branching by
introducing an explicit AIR instruction for it in the future.
* LLVM backend: implement lowering vector types
* Sema: Implement `slice.ptr` at comptime
* Value: improve `numberMin` and `numberMax` to support floats in
addition to integers, and make them behave properly in the presence
of NaN.
* `Module.Union.getFullyQualifiedName` returns a sentinel-terminated
slice so that backends that need null-termination do not need an
additional copy.
* Module.Union: implement a `getLayout` function which returns
information about ABI size and alignment so that the LLVM backend can
properly lower union types into llvm types.
* Sema: `resolveType` now returns `error.GenericPoison` rather than a
Type with tag `generic_poison`. Callsites that want to allow that
need to bypass this higher-level function.
* Sema: implement coercion of enums and enum literals to unions.
* Sema: fix comptime mutation of pointers to unions
* LLVM backend: fully implement proper lowering of union types and
values according to the union layout, and update the handling of AIR
instructions that deal with unions to support union layouts.
* LLVM backend: handle `decl_ref_mut`
- Maybe this should be unreachable since comptime vars should be
changed to be non-mutable when they go out of scope, but it's
harmless for the LLVM backend to support lowering the value.
* Type: fix `requiresComptime` for optionals, pointers, and some other
types. This function is still wrong for structs, unions, and enums.
* Make `alloc` AIR instructions call `resolveTypeLayout`.
* `Sema.zirResolveInferredAlloc` now calls `requireRuntimeBlock` in the
case that it operates on a non-comptime instruction.
* `Type.abiSize` and `Type.abiAlignment` now return 0 for `void`
* Sema: implement `resolveTypeFields` for unions.
* LLVM Backend: support `ptr_elem_ptr` when the element type is 0-bit.
* Type: improve `abiAlignment` implementation for structs to properly
handle fields with non-default alignment.
* Value: implement hashing array, vector, and structs.
* ZIR: the `array_type_sentinel` now has a source node attached to it
for proper error reporting.
* Refactor: move `Module.arrayType` to `Type.array`
* Value: the `bytes` and `array` tags now include the sentinel, if the
type has one. This simplifies comptime evaluation logic.
* Sema: fix `zirStructInitEmpty` to properly handle when the type is
void or a sentinel-terminated array. This handles the syntax `void{}`
and `[0:X]T{}`.
* Sema: fix the logic for reporting "cannot store runtime value in
compile time variable" as well as for emitting a runtime store when a
pointer value is comptime known but it is a global variable.
* Sema: implement elemVal for double pointer to array. This can happen
with this code for example: `var a: *[1]u8 = undefined; _ = a[0];`
* Sema: Rework the `storePtrVal` function to properly handle nested
structs and arrays.
- Also it now handles comptime stores through a bitcasted pointer.
When the pointer element type and the type according to the Decl
don't match, the element value is bitcasted before storage.
* Add AIR instructions: ret_ptr, ret_load
- This allows Sema to be blissfully unaware of the backend's decision
to implement by-val/by-ref semantics for struct/union/array types.
Backends can lower these simply as alloc, load, ret instructions,
or they can take advantage of them to use a result pointer.
* Add AIR instruction: array_elem_val
- Allows for better codegen for `Sema.elemVal`.
* Implement calculation of ABI alignment and ABI size for unions.
* Before appending the following AIR instructions to a block,
resolveTypeLayout is called on the type:
- call - return type
- ret - return type
- store_ptr - elem type
* Sema: fix memory leak in `zirArrayInit` and other cleanups to this
function.
* x86_64: implement the full x86_64 C ABI according to the spec
* Type: implement `intInfo` for error sets.
* Type: implement `intTagType` for tagged unions.
The Zig type tag `Fn` is now used exclusively for function bodies.
Function pointers are modeled as `*const T` where `T` is a `Fn` type.
* The `call` AIR instruction now allows a function pointer operand as
well as a function operand.
* Sema now has a coercion from function body to function pointer.
* Function type syntax, e.g. `fn()void`, now returns zig tag type of
Pointer with child Fn, rather than Fn directly.
- I think this should probably be reverted. Will discuss the lang
specs before doing this. Idea being that function pointers would
need to be specified as `*const fn()void` rather than `fn() void`.
LLVM backend:
* Enable calling the panic handler (previously this just
emitted `@breakpoint()` since the backend could not handle the panic
function).
* Implement sret
* Introduce `isByRef` and implement it for structs and arrays. Types
that are `isByRef` are now passed as pointers to functions, and e.g.
`elem_val` will return a pointer instead of doing a load.
* Move the function type creating code from `resolveLlvmFunction` to
`llvmType` where it belongs; now there is only 1 instance of this
logic instead of two.
* Add the `nonnull` attribute to non-optional pointer parameters.
* Fix `resolveGlobalDecl` not using fully-qualified names and not using
the `decl_map`.
* Implement `genTypedValue` for pointer-like optionals.
* Fix memory leak when lowering `block` instruction and OOM occurs.
* Implement volatile checks where relevant.
New ZIR instruction: elem_ptr_imm
This saves some memory for array literals since the element indexes are
communicated as immediate values rather than as references to other ZIR
instructions.
* Sema: fix a missing copy on enum tag values
* LLVM backend: fix lowering of enum constant values for enums with
specified tag values.
* Value: fix enumToInt for `enum_numbered` cases.
The float widening behavior tests which rely on compiler-rt symbols are
now passing.
* Update AIR instruction `intcast` to allow the dest type to be an
enum.
* LLVM backend: update `intcast` to support when the bit counts of
operand and dest type are the same. This was already a requirement of
the instruction previously.
* Type: `intInfo` supports the case when the type is an enum, and
retrieves the info for the integer tag type. This makes it pretty
easy for backends to implement `intcast` without having to care
explicitly that the new type is an enum. As a bonus, simple enums
never have to go through the type system; their signedness and bit
count are computed directly.
The "int to enum" behavior test case is now passing for stage2 in the
LLVM backend.
Before, Sema for comptime `@bitCast` would return the same Value but
change the Type. This gave invalid results because, for example, an
integer Value when the Type is a float would be interpreted numerically,
but `@bitCast` needs it to reinterpret how they would be stored in
memory.
This requires a mechanism to serialize a Value to a byte buffer and
deserialize a Value from a byte buffer.
Not done yet, but needs to happen: comptime dereferencing a pointer
to a Decl needs to perform a comptime bitcast on the loaded value.
Currently the value is silently wrong in the same way that `@bitCast`
was silently wrong before this commit.
The logic in Value for handling readFromMemory for large integers is
only correct for small integers. It needs to be fleshed out for proper
big integers.
As part of this change:
* std.math.big.Int: initial implementations of readTwosComplement and
writeTwosComplement. They only support bit_count <= 128 so far and
panic otherwise.
* compiler-rt: move the compareXf2 exports over to the stage2 section.
Even with the improvements in this commit, I'm still seeing test
failures in the widening behavior tests; more investigation is
needed.
