* AstGen: always use `typeof` and never `typeof_elem` on the
`switch_cond`/`switch_cond_ref` instruction because both variants
return a value and not a pointer.
- Delete the `typeof_elem` ZIR instruction since it is no longer
needed.
* Sema: validateUnionInit now recognizes a comptime mutable value and
no longer emits a compile error saying "cannot evaluate constant
expression"
- Still to-do is detecting comptime union values in a function that
is not being executed at compile-time.
- This is still to-do for structs too.
* Sema: when emitting a call AIR instruction, call resolveTypeLayout on
all the parameter types as well as the return type.
* `Type.structFieldOffset` now works for unions in addition to structs.
After a discussion about language specs, this seems like the best way to
go, because it's simpler to reason about both for humans and compilers.
The `bitcast_result_ptr` ZIR instruction is no longer needed.
This commit also implements writing enums, arrays, and vectors to
virtual memory at compile-time.
This unlocked some more of compiler-rt being able to build, which
in turn unlocks saturating arithmetic behavior tests.
There was also a memory leak in the comptime closure system which is now
fixed.
* 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.
* 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.
* 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.
isZigPrimitiveType had a bug where it checked the integer names (e.g.
u32) before primitives, leading it to incorrectly return `false` for
`undefined` which starts with `u`.
Related: #9928
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.
* AstGen: fix emitting `store_to_inferred_ptr` when it should be emitting
`store` for a variable that has an explicit alignment.
* Compilation: fix a couple memory leaks
* Sema: implement support for locals that have specified alignment.
* Sema: implement `@intCast` when it needs to emit an AIR instruction.
* Sema: implement `@alignOf`
* Implement debug printing for extended alloc ZIR instructions.
* Remove the builtins `@addWithSaturation`, `@subWithSaturation`,
`@mulWithSaturation`, and `@shlWithSaturation` now that we have
first-class syntax for saturating arithmetic.
* langref: Clarify the behavior of `@shlExact`.
* Ast: rename `bit_shift_left` to `shl` and `bit_shift_right` to `shr`
for consistency.
* Air: rename to include underscore separator with consistency with
the rest of the ops.
* Air: add shl_exact instruction
* Use non-extended tags for saturating arithmetic, to keep it
simple so that all the arithmetic operations can be done the same
way.
- Sema: unify analyzeArithmetic with analyzeSatArithmetic
- implement comptime `+|`, `-|`, and `*|`
- allow float operands to saturating arithmetic
* `<<|` allows any integer type for the RHS.
* C backend: fix rebase conflicts
* LLVM backend: reduce the amount of branching for arithmetic ops
* zig.h: fix magic number not matching actual size of C integer types
* AIR: add `mod` instruction for modulus division
- Implement for LLVM backend
* Sema: implement `@mod`, `@rem`, and `%`.
* Sema: fix comptime switch evaluation
* Sema: implement comptime shift left
* Sema: fix the logic inside analyzeArithmetic to handle all the
nuances between the different mathematical operations.
- Implement comptime wrapping operations
* Merge call zir instructions to make space for field_call
* Fix bug with comptime known anytype args
* Delete the param_type zir instruction
* Move some passing tests to stage 2
* Implement a.b() function calls
* Add field_call_bind support for call and field builtins
* AstGen: fix not emitting `struct_init_empty` when an explicit type is
present in struct initialization syntax.
* AstGen: these two syntaxes now lower to identical ZIR:
- `var a = A{ .b = c };`
- `var a = @as(A, .{ .b = c });`
* Zir: clarify `auto_enum_tag` in the doc comments.
* LLVM Backend: fix lowering of function return types when the type has
0 bits.
* prepare compiler-rt to support being compiled by stage2
- put in a few minor workarounds that will be removed later, such as
using `builtin.stage2_arch` rather than `builtin.cpu.arch`.
- only try to export a few symbols for now - we'll move more symbols
over to the "working in stage2" section as they become functional
and gain test coverage.
- use `inline fn` at function declarations rather than `@call` with an
always_inline modifier at the callsites, to avoid depending on the
anonymous array literal syntax language feature (for now).
* AIR: replace floatcast instruction with fptrunc and fpext for
shortening and widening floating point values, respectively.
* Introduce a new ZIR instruction, `export_value`, which implements
`@export` for the case when the thing to be exported is a local
comptime value that points to a function.
- AstGen: fix `@export` not properly reporting ambiguous decl
references.
* Sema: handle ExportOptions linkage. The value is now available to all
backends.
- Implement setting global linkage as appropriate in the LLVM
backend. I did not yet inspect the LLVM IR, so this still needs to
be audited. There is already a pending task to make sure the alias
stuff is working as intended, and this is related.
- Sema almost handles section, just a tiny bit more code is needed in
`resolveExportOptions`.
* Sema: implement float widening and shortening for both `@floatCast`
and float coercion.
- Implement the LLVM backend code for this as well.
There were two things to resolve here:
* Snektron's branch edited Zir printing, but in master branch
I moved the printing code from Zir.zig to print_zir.zig. So that
just had to be moved over.
* In master branch I fleshed out coerceInMemory a bit more, which
caused one of Snektron's test cases to fail, so I had to add
addrspace awareness to that. Once I did that the tests passed again.
This is a property which solely belongs to pointers to functions,
not to the functions themselves. This cannot be properly represented by
stage 2 at the moment, as type with zigTypeTag() == .Fn is overloaded for
for function pointers and function prototypes.
Adds AST generation for address spaces on pointers, function prototypes,
function declarations and variable declarations. In the latter two cases,
declaration properties were already stored more efficiently in a declaration
structure. To accomodate these for address spaces, the bit indicating presence
of a linksection attribute has been extended to include either linksection,
address space, or both.
* Implement Sema for `@cmpxchgWeak` and `@cmpxchgStrong`. Both runtime
and comptime codepaths are implement.
* Implement Codegen for LLVM backend and C backend.
* Add LazySrcLoc.node_offset_builtin_call_argX 3...5
* Sema: rework comptime control flow.
- `error.ComptimeReturn` is used to signal that a comptime function
call has returned a result (stored in the Inlining struct).
`analyzeCall` notices this and handles the result.
- The ZIR instructions `break_inline`, `block_inline`,
`condbr_inline` are now redundant and can be deleted. `break`,
`block`, and `condbr` function equivalently inside a comptime scope.
- The ZIR instructions `loop` and `repeat` also are modified to
directly perform comptime control flow inside a comptime scope,
skipping an unnecessary mechanism for analysis of runtime code.
This makes Zig perform closer to an interpreter when evaluating
comptime code.
* Sema: zirRetErrValue looks at Sema.ret_fn_ty rather than sema.func
for adding to the inferred error set. This fixes a bug for
inlined/comptime function calls.
* Implement ZIR printing for cmpxchg.
* stage1: make cmpxchg respect --single-threaded
- Our LLVM C++ API wrapper failed to expose this boolean flag before.
* Fix AIR printing for struct fields showing incorrect liveness data.
- adds 1 simple behavior tests for each
which does integer and vector ops at
runtime and comptime
- adds bigint_*_sat() methods for each
- use CreateIntrinsic() which accepts a
variable number of arguments to pass
the scale parameter
* update langref
- added case to test/compile_errors.zig given floats
- explain upstream bug in llvm.smul.fix.sat and link to #9643 in langref and commented out test cases
* sat-arithmetic: skip mul tests if arch == .wasm32 because ci is erroring with 'LLVM ERROR: Unable to expand fixed point multiplication' when compiling for wasm32
The big change in this commit is making `semaDecl` resolve the fields if
the Decl ends up being a struct or union. It needs to do this while
the `Sema` is still in scope, because it will have the resolved AIR
instructions that the field type expressions possibly reference. We do
this after the decl is populated and set to `complete` so that a `Decl`
may reference itself.
Everything else is fixes and improvements to make the test suite pass
again after making this change.
* New AIR instruction: `ptr_elem_ptr`
- Implemented for LLVM backend
* New Type tag: `type_info` which represents `std.builtin.TypeInfo`. It
is used by AstGen for the operand type of `@Type`.
* ZIR instruction `set_float_mode` uses `coerced_ty` to avoid
superfluous `as` instruction on operand.
* ZIR instruction `Type` uses `coerced_ty` to properly handle result
location type of operand.
* Fix two instances of `enum_nonexhaustive` Value Tag not handled
properly - it should generally be handled the same as `enum_full`.
* Fix struct and union field resolution not copying Type and Value
objects into its Decl arena.
* Fix enum tag value resolution discarding the ZIR=>AIR instruction map
for the child Sema, when they still needed to be accessed.
* Fix `zirResolveInferredAlloc` use-after-free in the AIR instructions
data array.
* Fix `elemPtrArray` not respecting const/mutable attribute of pointer
in the result type.
* Fix LLVM backend crashing when `updateDeclExports` is called before
`updateDecl`/`updateFunc` (which is, according to the API, perfectly
legal for the frontend to do).
* Fix LLVM backend handling element pointer of pointer-to-array. It
needed another index in the GEP otherwise LLVM saw the wrong type.
* Fix LLVM test cases not returning 0 from main, causing test failures.
Fixes a regression introduced in
6a5094872f10acc629543cc7f10533b438d0283a.
* Implement comptime shift-right.
* Implement `@Type` for integers and `@TypeInfo` for integers.
* Implement union initialization syntax.
* Implement `zirFieldType` for unions.
* Implement `elemPtrArray` for a runtime-known operand.
* Make `zirLog2IntType` support RHS of shift being `comptime_int`. In
this case it returns `comptime_int`.
The motivating test case for this commit was originally:
```zig
test "example" {
var l: List(10) = undefined;
l.array[1] = 1;
}
fn List(comptime L: usize) type {
var T = u8;
return struct {
array: [L]T,
};
}
```
However I changed it to:
```zig
test "example" {
var l: List = undefined;
l.array[1] = 1;
}
const List = blk: {
const T = [10]u8;
break :blk struct {
array: T,
};
};
```
Which ended up being a similar, smaller problem. The former test case
will require a similar solution in the implementation of comptime
function calls - checking if the result of the function call is a struct
or union, and using the child `Sema` before it is destroyed to resolve
the fields.
* Introduce `ret_load` ZIR instruction which does return semantics
based on a corresponding `ret_ptr` instruction. If the return type of
the function has storage for the return type, it simply returns.
However if the return type of the function is by-value, it loads the
return value from the `ret_ptr` allocation and returns that.
* AstGen: improve `finishThenElseBlock` to not emit break instructions
after a return instruction in the same block.
* Sema: `ret_ptr` instruction works correctly in comptime contexts.
Same with `alloc_mut`.
The test case with a recursive inline function having an implicitly
comptime return value now has a runtime return value because of the fact
that it calls a function in a non-comptime context.
When doing a function call, if the return type requires comptime, the
function is analyzed as an inline/comptime call.
There is an important TODO here. I will reproduce the comment from this
commit:
> In the case of a comptime/inline function call of a generic function,
> the function return type needs to be the resolved return type based on
> the function parameter type expressions being evaluated with comptime arguments
> passed in. Otherwise, it ends up being .generic_poison and failing the
> comptime/inline function call analysis.
* ZIR encoding for function instructions have a body for the return
type. This lets Sema for generic functions do the same thing it does
for parameters, handling `error.GenericPoison` in the evaluation of
the return type by marking the function as generic.
* Sema: fix missing block around the new Decl arena finalization. This
led to a memory corruption.
* Added some floating point support to the LLVM backend but didn't get
far enough to pass any new tests.
Module has a new field `monomorphed_funcs` which stores the set of
`*Module.Fn` objects which are generic function instantiations.
The hash is based on hashes of comptime values of parameters known to be
comptime based on an explicit comptime keyword or must-be-comptime
type expressions that can be evaluated without performing monomorphization.
This allows function calls to be semantically analyzed cheaply for
generic functions which are already instantiated.
The table is updated with a single `getOrPutAdapted` in the semantic
analysis of `call` instructions, by pre-allocating the `Fn` object and
passing it to the child `Sema`.
AstGen result locations now have a `coerced_ty` tag which is the same as
`ty` except it assumes that Sema will do a coercion, so it does not
redundantly add an `as` instruction into the ZIR code. This results in
cleaner ZIR and about a 14% reduction of ZIR bytes.
param and param_comptime ZIR instructions now have a block body for
their type expressions. This allows Sema to skip evaluation of the
block in the case that the parameter is comptime-provided. It also
allows a new mechanism to function: when evaluating type expressions of
generic functions, if it would depend on another parameter, it returns
`error.GenericPoison` which bubbles up and then is caught by the
param/param_comptime instruction and then handled.
This allows parameters to be evaluated independently so that the type
info for functions which have comptime or anytype parameters will still
have types populated for parameters that do not depend on values of
previous parameters (because evaluation of their param blocks will return
successfully instead of `error.GenericPoison`).
It also makes iteration over the block that contains function parameters
slightly more efficient since it now only contains the param
instructions.
Finally, it fixes the case where a generic function type expression contains
a function prototype. Formerly, this situation would cause shared state
to clobber each other; now it is in a proper tree structure so that
can't happen. This fix also required adding a field to Sema
`comptime_args_fn_inst` to make sure that the `comptime_args` field
passed into Sema is applied to the correct `func` instruction.
Source location for `node_offset_asm_ret_ty` is fixed; it was pointing at
the asm output name rather than the return type as intended.
Generic function instantiation is fixed, notably with respect to
parameter type expressions that depend on previous parameters, and with
respect to types which must be always comptime-known. This involves
passing all the comptime arguments at a callsite of a generic function,
and allowing the generic function semantic analysis to coerce the values
to the proper types (since it has access to the evaluated parameter type
expressions) and then decide based on the type whether the parameter is
runtime known or not. In the case of explicitly marked `comptime`
parameters, there is a check at the semantic analysis of the `call`
instruction.
Semantic analysis of `call` instructions does type coercion on the
arguments, which is needed both for generic functions and to make up for
using `coerced_ty` result locations (mentioned above).
Tasks left in this branch:
* Implement the memoization table.
* Add test coverage.
* Improve error reporting and source locations for compile errors.
The general strategy is that Sema will pre-map comptime arguments into
the inst_map, and then re-run the block body that contains the `param`
and `func` instructions. This re-runs all the parameter type expressions
except with comptime values populated.
In Sema, param instructions are now handled specially: they detect
whether they are comptime-elided or not. If so, they skip putting a
value in the inst_map, since it is already pre-populated. If not, then
they append to the `fields` field of `Sema` for use with the `func`
instruction.
So when the block body is re-run, a new function is generated with
all the comptime arguments elided, and the new function type has only
runtime parameters in it. TODO: give the generated Decls better names
than "foo__anon_x".
The new function is then added to the work queue to have its body
analyzed and a runtime call AIR instruction to the new function is
emitted.
When the new function gets semantically analyzed, comptime parameters are
pre-mapped to the corresponding `comptime_args` values rather than
mapped to an `arg` AIR instruction. `comptime_args` is a new field that
`Fn` has which is a `TypedValue` for each parameter. This field is non-null
for generic function instantiations only. The values are the comptime
arguments. For non-comptime parameters, a sentinel value is used. This is
because we need to know the information of which parameters are
comptime-known.
Additionally:
* AstGen: align and section expressions are evaluated in the scope that
has comptime parameters in it.
There are still some TODO items left; see the BRANCH_TODO file.
* ZIR function instructions encode the index of the block that
contains the function instruction. This allows Zig to later scan the
block and find the parameter instructions, which is needed for
semantically analyzing function bodies.
* Runtime function calls insert AIR arg instructions and then inserts
Sema inst_map entries mapping the ZIR param instructions to them.
* comptime/inline function call inserts Sema inst_map entries mapping
the ZIR param instructions to the AIR callsite arguments.
With this commit we are back to the tests passing.
ZIR encoding for functions is changed in preparation for generic
function support. As an example:
```zig
const std = @import("std");
const expect = std.testing.expect;
test "example" {
var x: usize = 0;
x += checkSize(i32, 1);
x += checkSize(bool, true);
try expect(x == 5);
}
fn checkSize(comptime T: type, x: T) usize {
_ = x;
return @sizeOf(T);
}
```
Previous ZIR for the `checkSize` function:
```zir
[165] checkSize line(10) hash(0226f62e189fd0b1c5fca02cf4617562): %55 = block_inline({
%56 = decl_val("T") token_offset:11:35
%57 = as_node(@Ref.type_type, %56) node_offset:11:35
%69 = extended(func([comptime @Ref.type_type, %57], @Ref.usize_type, {
%58 = arg("T") token_offset:11:23
%59 = as_node(@Ref.type_type, %58) node_offset:11:35
%60 = arg("x") token_offset:11:32
%61 = dbg_stmt(11, 4)
```
ZIR for the `checkSize` function after this commit:
```zir
[157] checkSize line(10) hash(0226f62e189fd0b1c5fca02cf4617562): %55 = block_inline({
%56 = param_comptime("T", @Ref.type_type) token_offset:11:23
%57 = as_node(@Ref.type_type, %56) node_offset:11:35
%58 = param("x", %57) token_offset:11:32
%67 = func(@Ref.usize_type, {
%59 = dbg_stmt(11, 4)
```
Noted differences:
* Previously the type expression was redundantly repeated.
* Previously the parameter names were redundantly stored in the ZIR
extra array.
* Instead of `arg` ZIR instructions as the first instructions within a
function body, they are now outside the function body, in the same
block as the `func` instruction. There are variants:
- param
- param_comptime
- param_anytype
- param_anytype_comptime
* The param instructions additionally encode the type.
* Because of the param instructions, the `func` instruction no longer
encodes the list of parameter types or the comptime bits.
It's implied that Sema will collect the parameters so that when a `func`
instruction is encountered, they will be implicitly used to construct
the function's type. This is so that we can satisfy all 3 ways of
performing semantic analysis on a function:
1. runtime: Sema will insert AIR arg instructions for each parameter,
and insert into the Sema inst_map ZIR param => AIR arg.
2. comptime/inline: Sema will insert into the inst_map ZIR param =>
callsite arguments.
3. generic: Sema will map *only the comptime* ZIR param instructions to
the AIR instructions for the comptime arguments at the callsite, and
then re-run Sema for the function's Decl. This will produce a new
function which is the monomorphized function.
Additionally:
* AstGen: Update usage of deprecated `ensureCapacity` to
`ensureUnusedCapacity` or `ensureTotalCapacity`.
* Introduce `Type.fnInfo` for getting a bunch of data about a function
type at once, and use it in `analyzeCall`.
This commit starts a branch to implement generic functions in stage2.
Test regressions have not been addressed yet.
`func_extended` ZIR instructions now have a one of the unused flags used
as a `has_comptime_bits` boolean. When set, it means 1 or more
parameters are `comptime`. In this case, there is a u32 per every 32
parameters (usually just 1 u32) with each bit indicating whether the
corresponding parameter is `comptime`.
Sema uses this information to correctly mark generic functions as
generic. There is now a TODO compile error in place in case a generic
function call happens. A future commit will do the generic function call
implementation.
@select(
comptime T: type,
pred: std.meta.Vector(len, bool),
a: std.meta.Vector(len, T),
b: std.meta.Vector(len, T)
) std.meta.Vector(len, T)
Constructs a vector from a & b, based on the values in the predicate vector. For indices where the predicate value is true, the corresponding
element from the a vector is selected, and otherwise from b.
* There is now a main_pkg in addition to root_pkg. They are usually the
same. When using `zig test`, main_pkg is the user's source file and
root_pkg has the test runner.
* scanDecl no longer looks for test decls outside the package being
tested. honoring `--test-filter` is still TODO.
* test runner main function has a void return value rather than
`anyerror!void`
* Sema is improved to generate better AIR for for loops on slices.
* Sema: fix incorrect capacity calculation in zirBoolBr
* Sema: add compile errors for trying to use slice fields as an lvalue.
* Sema: fix type coercion for error unions
* Sema: fix analyzeVarRef generating garbage AIR
* C codegen: fix renderValue for error unions with 0 bit payload
* C codegen: implement function pointer calls
* CLI: fix usage text
Adds 4 new AIR instructions:
* slice_len, slice_ptr: to get the ptr and len fields of a slice.
* slice_elem_val, ptr_slice_elem_val: to get the element value of
a slice, and a pointer to a slice.
AstGen gains a new functionality:
* One of the unused flags of struct decls is now used to indicate
structs that are known to have non-zero size based on the AST alone.
Additionally: ZIR encoding for floats now supports float literals up to
f64, not only f32. This is because we no longer need a source location
for this instruction.
This commit changes the AIR file and the documentation of the memory
layout. The actual work of modifying the surrounding code (in Sema and
codegen) is not yet done.
