That happens after a function body is analyzed. This prevents circular
dependency compile errors and yet a way to mark types that need to be
fully resolved before a given function is sent to the codegen backend.
Implements lowering constants for pointers of value 'opt_payload_ptr'.
The offset is calculated by determining the abi size of the full type and
then substracting the payload size.
Error sets contain the entire global error set.
Users are often switching on specific errors only present within that operand.
This means that cases are almost always sparse and not contiguous.
For this reason, we will instead emit the default case for error values not present in
that specific operand error set. This is fine as those cases will never be hit,
as prevented by the type system.
By still allowing jump tables for those cases, rather than if-else chains, we save runtime cost
as well as binary size.
This implements the `error_name` instruction, which is emit for runtime `@errorName` callsites.
The implementation works by creating 2 symbols and corresponding atoms.
The initial symbol contains a table which each element consisting of a slice where the ptr field
points towards the error name, and the len field contains the error name length without the sentinel.
The secondary symbol contains a list of all error names from the global error set.
During the error_name instruction, we first get a pointer to the first symbol.
Then based on the operand we perform pointer arithmetic, to get the correct index into this table.
e.g. error index 2 = ptr + (2 * ptr size). The result of this will be stored in a local
and then returned as instruction result.
During `flush()` we populate the error names table by looping over the global error set
and creating a relocation for each error name. This relocation is appended to the table symbol.
Then finally, this name is written to the names list itself.
Finally, both symbols' atom are allocated within the rest of the binary.
When no error name is referenced, the `error_name_symbol` is never set, and therefore
no error name table will be emit into the final binary.
The existing `cmp_*` instructions get their result type from `lhs`, but
vector comparison will always return a vector of bools with only the
length derived from its operands. This necessitates the creation of a
new AIR instruction.
This implements improvements/fixes to get all the union, tuple, and array behavior tests passing.
Previously, we lowered parent pointers for field_ptr and element_ptr incompletely. This has now
been improved to recursively lower such pointer.
Also a fix was done to `generateSymbol` when checking a container's layout.
Previously it was assumed to always be a struct. However, the type can also be a tuple, and therefore
panicking. Updating to ask a type's container layout instead allows us to keep a singular branch for both cases.
Notably, Value.eql and Value.hash are improved to treat NaN as equal to
itself, so that Type/Value can be hash map keys. Likewise float hashing
normalizes the float value before computing the hash.
When the length is comptime-known, we perform an inline loop instead of emitting
a runtime loop into the binary.
This also allows us to easily write 'undefined' to aggregate types.
We now do this when we set the error tag of an error union where the payload will be set to undefined.
This implements the `memcpy` instruction and also updates the inline memcpy calls
to make use of the same implementation. We use the fast-loop when the length is comptime known,
and use a runtime loop when the length is runtime known.
We also perform feature-dection to emit a simply wasm memory.copy instruction when the feature
'bulk-memory' is enabled. (off by default).
Adds 2 new AIR instructions:
* dbg_var_ptr
* dbg_var_val
Sema no longer emits dbg_stmt AIR instructions when strip=true.
LLVM backend: fixed lowerPtrToVoid when calling ptrAlignment on
the element type is problematic.
LLVM backend: fixed alloca instructions improperly getting debug
location annotated, causing chaotic debug info behavior.
zig_llvm.cpp: fixed incorrect bindings for a function that should use
unsigned integers for line and column.
A bunch of C test cases regressed because the new dbg_var AIR
instructions caused their operands to be alive, exposing latent bugs.
Mostly it's just a problem that the C backend lowers mutable
and const slices to the same C type, so we need to represent that in the
C backend instead of printing two duplicate typedefs.
* use the real start code for LLVM backend with x86_64-linux
- there is still a check for zig_backend after initializing the TLS
area to skip some stuff.
* introduce new AIR instructions and implement them for the LLVM
backend. They are the same as `call` except with a modifier.
- call_always_tail
- call_never_tail
- call_never_inline
* LLVM backend calls hasRuntimeBitsIgnoringComptime in more places to
avoid unnecessarily depending on comptimeOnly being resolved for some
types.
* LLVM backend: remove duplicate code for setting linkage and value
name. The canonical place for this is in `updateDeclExports`.
* LLVM backend: do some assembly template massaging to make `%%`
rendered as `%`. More hacks will be needed to make inline assembly
catch up with stage1.
This implements the initial fptrunc instruction. For all other floating-point truncating,
a call to compiler-rt is required. (This also updates fpext to emit the same error).
- Implement switching over booleans and pointers.
- Fix sparse-detection where the lowest value was never truly set
as it started at a non-zero number and the case was > 50.
- Fix indexing the jump table by ensuring it starts indexing from 0.
Like decl code generation, also unify the wasm backend and the wasm linker to call into
the general purpose `codegen.zig` to generate the code for a function.
To unify the wasm backend with the other backends, we will now call `generateSymbol` to
lower a Decl into bytes. This means we also have to change some function signatures
to comply with the linker interface.
Since the general purpose generateSymbol is less featureful than wasm's, some tests are
temporarily disabled.
* AIR: use pl_op instead of ty_pl for wasm_memory_size. No need to
store the type because the type is always `u32`.
* AstGen: use coerced_ty for `@wasmMemorySize` and `@wasmMemoryGrow`
and do the coercions in Sema.
* Sema: use more accurate source locations for errors.
* Provide more information in the compiler error message.
* Codegen: use liveness data to avoid lowering unused
`@wasmMemorySize`.
* LLVM backend: add implementation
- I wasn't able to test it because we are hitting a linker error for
`-target wasm32-wasi -fLLVM`.
* C backend: use `zig_unimplemented()` instead of silently doing wrong
behavior for these builtins.
* behavior tests: branch only on stage2_arch for inclusion of the
wasm.zig file. We would change it to `builtin.cpu.arch` but that is
causing a compiler crash on some backends.
This implements the wasm builtins by lowering to builtins that are supported by c-compilers.
In this case: Clang.
This also simplifies the `AIR` instruction as it now uses the payload field of `ty_pl` and `pl_op`
directly to store the index argument rather than storing it inside Extra. This saves us 4 bytes
per builtin call.
Similarly to the other wasm builtin, this implements the grow variation where the memory
index is a comptime known value. The operand as well as the result are runtime values.
This also verifies during semantic analysis the target we're building for is wasm, or else
emits a compilation error. This means that other backends do not have to handle this AIR instruction,
other than the wasm and LLVM backends.
This implements the `wasmMemorySize` builtin, in Sema and the Wasm backend.
The Stage2 implementation differs from stage1 in the way that `index` must be a comptime value.
The stage1 variant is incorrect, as the index is part of the instruction encoding, and therefore,
cannot be a runtime value.
The ZIR instruction `union_init_ptr` is renamed to `union_init`.
I made it always use by-value semantics for now, not taking the time to
invest in result location semantics, in case we decide to change the
rules for unions. This way is much simpler.
There is a new AIR instruction: union_init. This is for a comptime known
tag, runtime-known field value.
vector_init is renamed to aggregate_init, which solves a TODO comment.
Rather than ping ponging between codegen and the linker to generate the symbols/atoms
for a local constant and its relocations. We now create all neccesary objects within the linker.
This simplifies the code as we can now simply call `lowerUnnamedConst` from anywhere in codegen,
allowing us to further improve lowering constants into .rodata so we do not have to sacrifice
lowering certain types such as decl_ref's where its type is a slice.
We now correctly implement exporting decls. This means it is possible to export
a decl with a different name than the decl that is doing the export.
This also sets the symbols with the correct flags, so when we emit a relocatable
object file, a linker can correctly resolve symbols and/or export the symbol to the host environment.
This commit also includes fixes to ensure relocations have the correct offset to how other
linkers will expect the offset, rather than what we use internally.
Other linkers accept the offset, relative to the section.
Internally we use an offset relative to the atom.
This implements the `field_ptr` value for pointers. As the value only provides us with the index,
we must calculate the offset from the container type using said index. (i.e. the offset from a struct field at index 2).
Besides this, small miscellaneous fixes/updates were done to get remaining behavior tests passing:
- We start the function table index at 1, so unresolved function pointers don't can be null-checked properly.
- Implement genTypedValue for floats up to f64.
- Fix zero-sized arguments by only creating `args` for non-zero-sized types.
- lowerConstant now works for all decl_ref's.
- lowerConstant properly lowers optional pointers, so `null` pointers are lowered to `0`.
Rather than using runtime to perform pointer arithmetic to set the stack offset as
a pointer into a local, we now store the offset as a WValue from the bottom of the stack.
This has the benefit of less instructions, few locals, and less performance impact when
we allocate a value on the virtual stack.
* pass more x64 behavior tests
* return with a TODO error when lowering a decl with no runtime bits
* insert some debug logs for tracing recursive descent down the
type-value tree when lowering types
* print `Decl`'s name when print debugging `decl_ref` value
This updates the test runner for stage2 to emit to stdout with the passed, skipped and failed tests
similar to the LLVM backend.
Another change to this is the start function, as it's now more in line with stage1's.
The stage2 test infrastructure for wasm/wasi has been updated to reflect this as well.
