The function table contains all function pointers that are called
by using call_indirect. During codegen, we create a relocation
where the linker will resolve the correct index into the table and stores
this value within the data section at the location of the pointer.
We now resolve relocations for globals, memory addresses and function indexes.
Besides above, we now also emit imported functions correctly and create a
corresponding undefined symbol for it, where as we create a defined symbol
for all other cases.
TODO: Make incrememental compilation work again with new linker infrastructure
- Converts previous `DeclBlock` into `Atom`'s to also make them compatible when
the rest of zlwd gets upstreamed and we can link with other object files.
- Resolves function signatures and removes any duplicates, saving us a lot of
potential bytes for larger projects.
- We now create symbols for each decl of the respective type
- We can now (but not implemented yet) perform proper relocations.
- Having symbols and segment_info allows us to create an object file
for wasm.
* Introduce a mechanism into Sema for emitting a compile error when an
integer is too big and we need it to fit into a usize.
* Add `@intCast` where necessary
* link/MachO: fix an unnecessary allocation when all that was happening
was appending zeroes to an ArrayList.
* Add `error.Overflow` as a possible error to some codepaths, allowing
usage of `math.intCast`.
closes#9710
Ensure all previous test cases are still passing, as well as add some basic tests for now
for testing pointers to the stack.
This means we can start implementing wasm's C ABI found at: https://github.com/WebAssembly/tool-conventions/blob/main/BasicCABI.md
We also simplified the block logic by always using 'void' block types and instead writing the value to a local,
which can then be referenced by continues instructions, as done currently by AIR.
Besides this, we also no longer need to insert blocks at an offset, as we simply write the saved temporary
after we create the block.
Rather than writing the alignment in its natural form, wasm binaries encode the alignment of types as the exponent of a power of 2.
So rather than performing this encoding during AIR->MIR, we do this while emitting MIR->binary encoding.
This allows us to keep alignment logic to its natural form while doing calculations (Which is what we need during linking as well).
We also implement optionals and pointers to an optional.
This implements basic calling convention resolving. This means that for
types such as an error union, we will now allocate space on the stack to store the result.
This result will then be saved in a temporary local at the callsite.
By calculating the abi size of the struct, we move the stack
pointer and store each field depending on its size (i.e. a 1-byte field will use i32.store8).
This commit adds all required opcodes to perform those stores and loads.
This also gets rid of `mir_offset` as we now save results of binary operations into
locals and emit its result onto the stack within condbr instead. This makes everything a lot
simpler but also more robust.
In the future, we could look into an algorithm to re-use such locals.
For struct fields we use the new `local_with_offset` tag. This stores the struct's
stack pointer as well as the field's offset from that stack pointer.
`allocLocal` will now always allocate a single local, using a given type.
All non-temporary locals will now use stack memory.
When `airAlloc` is called, we create a new local, move the stack pointer,
and write its offset into the local. Arguments act as a register and do not
use any stack space.
We no longer use offsets for binary operations, but instead write the result
into a local. In this case, the local is simply used as a register, and does not
require stack space. This allows us to ensure the order of instructions is correct,
and we no longer require any patching/inserting at a specific offset.
print_air was missing the logic to print the type of a `ty_str`.
* wasm: Move wasm's codegen to arch/wasm/CodeGen.zig
* wasm: Define Wasm's Mir
This declares the initial most-used instructions for wasm as
well as the data that represents them.
TODO: Add binary operand opcodes.
By re-using the wasm opcode values, we can emit each opcode very easily
by simply using `@enumToInt()`. However, this poses a possible problem:
If we use all of wasm's opcodes, it leaves us no room to use synthetic opcodes such as debugging instructions.
We could use reserved opcodes, but the wasm spec may use them at some point.
TODO: Check if we should perhaps use a 16bit tag where the highest bits are used for synthetic opcodes.
* wasm: Define basic Emit structure
* wasm: Implement corresponding Emit functions for MIR
* wasm: Initial lowering to MIR
- This implements lowering to MIR from AIR for storing and loading of locals
as well as emitting immediates.
- Relocating function indexes has been simplified a lot as well as we no
longer need to patch offsets and we write a relocatable value instead.
- Locals are now emitted at the beginning of the function section entry
meaning all offsets we generate are stable.
* wasm: Lower all AIR instructions to MIR
* wasm: Implement remaining MIR instructions
* wasm: Fix function relocations
* wasm: Get all tests working
* wasm: Make `Data` 4 bytes instead of 8.
- 64bit immediates are now stored in 2 seperate u32's.
- 64bit floats are now stored in 2 seperate u32's.
- `mem_arg` is now stored as a seperate payload in extra.
