The fundamental problem is that the target distance of jump-like operations may change in the DWARF expression translation process. Intervening DW_OP_deref will expand to about 10 bytes, for example.
So the jumps must be relocated. We approach this task by inserting artificial LandingPad markers (new CompiledExpressionParts constructors) into the parsed vector at actual Jump targets.
LandingPads are identified by JumpTargetMarker tokens which are generated on the fly.
Additionally we now parse the Jump instructions. These also get their corresponding JumpTargetMarker token.
We bail in two situations:
frame_base is too complicated (i.e. itself contains Jump)
some jump distance in the original expression is fishy.
No point in resorting to LEB128 encoding for such constants,
using the native `u32` is faster and more compact.
Adds `write_u32` method to facilitate this.
Provide automatic translation to opcodes from DW_OP_* identifiers. They are looked up from gimli.
Since DW_OP_WASM_location is not contained in gimli yet, we take care of manually translating it.
* Refactor where results of compilation are stored
This commit refactors the internals of compilation in Wasmtime to change
where results of individual function compilation are stored. Previously
compilation resulted in many maps being returned, and compilation
results generally held all these maps together. This commit instead
switches this to have all metadata stored in a `CompiledFunction`
instead of having a separate map for each item that can be stored.
The motivation for this is primarily to help out with future
module-linking-related PRs. What exactly "module level" is depends on
how we interpret modules and how many modules are in play, so it's a bit
easier for operations in wasmtime to work at the function level where
possible. This means that we don't have to pass around multiple
different maps and a function index, but instead just one map or just
one entry representing a compiled function.
Additionally this change updates where the parallelism of compilation
happens, pushing it into `wasmtime-jit` instead of `wasmtime-environ`.
This is another goal where `wasmtime-jit` will have more knowledge about
module-level pieces with module linking in play. User-facing-wise this
should be the same in terms of parallel compilation, though.
The ultimate goal of this refactoring is to make it easier for the
results of compilation to actually be a set of wasm modules. This means
we won't be able to have a map-per-metadata where the primary key is the
function index, because there will be many modules within one "object
file".
* Don't clear out fields, just don't store them
Persist a smaller set of fields in `CompilationArtifacts` instead of
trying to clear fields out and dynamically not accessing them.
* Don't re-parse wasm for debuginfo
This commit updates debuginfo parsing to happen during the main
translation of the original wasm module. This avoid re-parsing the wasm
module twice (at least the section-level headers). Additionally this
ties debuginfo directly to a `ModuleTranslation` which makes it easier
to process debuginfo for nested modules in the upcoming module linking
proposal.
The changes here are summarized by taking the `read_debuginfo` function
and merging it with the main module translation that happens which is
driven by cranelift. Some new hooks were added to the module environment
trait to support this, but most of it was integrating with existing hooks.
* Fix tests in debug crate
This commit is intended to update wasmparser to 0.59.0. This primarily
includes bytecodealliance/wasm-tools#40 which is a large update to how
parsing and validation works. The impact on Wasmtime is pretty small at
this time, but over time I'd like to refactor the internals here to lean
more heavily on that upstream wasmparser refactoring.
For now, though, the intention is to get on the train of wasmparser's
latest `main` branch to ensure we get bug fixes and such.
As part of this update a few other crates and such were updated. This is
primarily to handle the new encoding of `ref.is_null` where the type is
not part of the instruction encoding any more.
- Create the ELF image from Compilation
- Create CodeMemory from the ELF image
- Link using ELF image
- Remove creation of GDB JIT images from crates/debug
- Move make_trampoline from compiler.rs
This somewhat cuts down on duplicate dependencies. `wast` is used in a much older version (`11.0.0`) by `witx`, and can be updated without issues there as well, but this at least gets us from 3 copies to 2.
* Refactor how relocs are stored and handled
* refactor CompiledModule::instantiate and link_module
* Refactor DWARF creation: split generation and serialization
* Separate DWARF data transform from instantiation
* rm LinkContext
There was a bug how value labels were resolved, which caused some DWARF expressions not be transformed, e.g. those are in the registers.
* Implements FIXME in expression.rs
* Move TargetIsa from CompiledExpression structure
* Fix expression format for GDB
* Add tests for parsing
* Proper logic in ValueLabelRangesBuilder::process_label
* Tests for ValueLabelRangesBuilder
* Refactor build_with_locals to return Iterator instead of Vec<_>
* Misc comments and magical numbers
Support a few DWARF-5 only features:
* read .debug_addr
* read .debug_rnglists
* read .debug_loclists when present
* add dwarf-5 test
* read .debug_addr
* read .debug_rnglists
* read .debug_loclists when present
* support .debug_line_str and .debug_str_offsets
Co-authored-by: Yury Delendik <ydelendik@mozilla.com>
This commit makes the following changes to unwind information generation in
Cranelift:
* Remove frame layout change implementation in favor of processing the prologue
and epilogue instructions when unwind information is requested. This also
means this work is no longer performed for Windows, which didn't utilize it.
It also helps simplify the prologue and epilogue generation code.
* Remove the unwind sink implementation that required each unwind information
to be represented in final form. For FDEs, this meant writing a
complete frame table per function, which wastes 20 bytes or so for each
function with duplicate CIEs. This also enables Cranelift users to collect the
unwind information and write it as a single frame table.
* For System V calling convention, the unwind information is no longer stored
in code memory (it's only a requirement for Windows ABI to do so). This allows
for more compact code memory for modules with a lot of functions.
* Deletes some duplicate code relating to frame table generation. Users can
now simply use gimli to create a frame table from each function's unwind
information.
Fixes#1181.
This exposes the functionality of `fde::map_reg` on the `TargetIsa` trait, avoiding compilation errors on architectures where register mapping is not yet supported. The change is conditially compiled under the `unwind` feature.
* Wasmtime 0.15.0 and Cranelift 0.62.0. (#1398)
* Bump more ad-hoc versions.
* Add build.rs to wasi-common's Cargo.toml.
* Update the env var name in more places.
* Remove a redundant echo.
Both cranelift-codegen and wasmtime-debug need to map Cranelift registers to Gimli registers. Previously both crates had an almost-identical `map_reg` implementation. This change:
- removes the wasmtime-debug implementation
- improves the cranelift-codegen implementation with custom errors
- exposes map_reg in `cranelift_codegen::isa::fde::map_reg` and subsequently `wasmtime_environ::isa::fde::map_reg`
* Bump Wasmtime to 0.14.0.
* Update the publish script for the wiggle crate wiggle.
* More fixes.
* Fix lightbeam depenency version.
* cargo update
* Cargo update wasi-tests too.
And add cargo update to the version-bump scripts.
The crates/debug/src/transform/address_transform.rs is unoptimized in terms of data structures. This PR refactors this file to remove creation of intermediate in-heap structures, thus improves overall performance of the DWARF transformation.
* Reduce amount of memory allocated in translate_ranges_raw
* refactor translate_ranges
* Don't transform non-unit .debug_line
* type annotation for TransformRangeXXXIter's
* Fix empty generated wasm positions
