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Move all trampoline compilation to wasmtime-cranelift (#3176)

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* Move all trampoline compilation to `wasmtime-cranelift`

This commit moves compilation of all the trampolines used in wasmtime
behind the `Compiler` trait object to live in `wasmtime-cranelift`. The
long-term goal of this is to enable depending on cranelift *only* from
the `wasmtime-cranelift` crate, so by moving these dependencies we
should make that a little more flexible.

* Fix windows build
This commit is contained in:
Alex Crichton
2021-08-12 16:58:21 -05:00
committed by GitHub
parent 2da1b9d375
commit e9f33fc618
24 changed files with 396 additions and 482 deletions
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9
crates/jit/Cargo.toml
View File

@@ -11,11 +11,6 @@ repository = "https://github.com/bytecodealliance/wasmtime"
edition = "2018"
[dependencies]
cranelift-codegen = { path = "../../cranelift/codegen", version = "0.76.0", features = ["enable-serde"] }
cranelift-entity = { path = "../../cranelift/entity", version = "0.76.0", features = ["enable-serde"] }
cranelift-wasm = { path = "../../cranelift/wasm", version = "0.76.0", features = ["enable-serde"] }
cranelift-native = { path = "../../cranelift/native", version = "0.76.0" }
cranelift-frontend = { path = "../../cranelift/frontend", version = "0.76.0" }
wasmtime-environ = { path = "../environ", version = "0.29.0" }
wasmtime-runtime = { path = "../runtime", version = "0.29.0" }
wasmtime-cranelift = { path = "../cranelift", version = "0.29.0" }
@@ -45,10 +40,10 @@ lightbeam = ["wasmtime-lightbeam"]
jitdump = ["wasmtime-profiling/jitdump"]
vtune = ["wasmtime-profiling/vtune"]
parallel-compilation = ["rayon"]
all-arch = ["cranelift-codegen/all-arch"]
all-arch = ["wasmtime-cranelift/all-arch"]
# Use the old x86 backend.
old-x86-backend = ["cranelift-codegen/old-x86-backend"]
old-x86-backend = ["wasmtime-cranelift/old-x86-backend"]
[badges]
maintenance = { status = "actively-developed" }

15
crates/jit/src/code_memory.rs
View File

@@ -5,6 +5,7 @@ use crate::object::{
ObjectUnwindInfo,
};
use crate::unwind::UnwindRegistry;
use anyhow::{Context, Result};
use object::read::{File as ObjectFile, Object, ObjectSection, ObjectSymbol};
use region;
use std::collections::BTreeMap;
@@ -24,8 +25,8 @@ struct CodeMemoryEntry {
}
impl CodeMemoryEntry {
fn with_capacity(cap: usize) -> Result<Self, String> {
let mmap = ManuallyDrop::new(Mmap::with_at_least(cap).map_err(|e| e.to_string())?);
fn with_capacity(cap: usize) -> Result<Self> {
let mmap = ManuallyDrop::new(Mmap::with_at_least(cap)?);
let registry = ManuallyDrop::new(UnwindRegistry::new(mmap.as_ptr() as usize));
Ok(Self {
mmap,
@@ -119,7 +120,7 @@ impl CodeMemory {
pub fn allocate_for_function<'a>(
&mut self,
func: &'a CompiledFunction,
) -> Result<&mut [VMFunctionBody], String> {
) -> Result<&mut [VMFunctionBody]> {
let size = Self::function_allocation_size(func);
let (buf, registry, start) = self.allocate(size)?;
@@ -167,7 +168,7 @@ impl CodeMemory {
/// * The offset within the current mmap that the slice starts at
///
/// TODO: Add an alignment flag.
fn allocate(&mut self, size: usize) -> Result<(&mut [u8], &mut UnwindRegistry, usize), String> {
fn allocate(&mut self, size: usize) -> Result<(&mut [u8], &mut UnwindRegistry, usize)> {
assert!(size > 0);
if match &self.current {
@@ -249,7 +250,7 @@ impl CodeMemory {
}
/// Pushes the current entry and allocates a new one with the given size.
fn push_current(&mut self, new_size: usize) -> Result<(), String> {
fn push_current(&mut self, new_size: usize) -> Result<()> {
let previous = mem::replace(
&mut self.current,
if new_size == 0 {
@@ -279,7 +280,7 @@ impl CodeMemory {
&'a mut self,
obj: &ObjectFile,
unwind_info: &[ObjectUnwindInfo],
) -> Result<CodeMemoryObjectAllocation<'a>, String> {
) -> Result<CodeMemoryObjectAllocation<'a>> {
let text_section = obj.section_by_name(".text").unwrap();
if text_section.size() == 0 {
@@ -296,7 +297,7 @@ impl CodeMemory {
buf.copy_from_slice(
text_section
.data()
.map_err(|_| "cannot read section data".to_string())?,
.with_context(|| "cannot read section data")?,
);
// Track locations of all defined functions and trampolines.

8
crates/jit/src/compiler.rs
View File

@@ -132,6 +132,11 @@ impl Compiler {
&self.features
}
/// Return the underlying compiler in use
pub fn compiler(&self) -> &dyn EnvCompiler {
&*self.compiler
}
/// Compile the given function bodies.
pub fn compile<'data>(
&self,
@@ -166,8 +171,7 @@ impl Compiler {
vec![]
};
let (obj, unwind_info) =
build_object(&*self.isa, &translation, types, &funcs, dwarf_sections)?;
let (obj, unwind_info) = build_object(self, &translation, types, &funcs, dwarf_sections)?;
Ok(Compilation {
obj,

18
crates/jit/src/instantiate.rs
View File

@@ -7,6 +7,7 @@ use crate::code_memory::CodeMemory;
use crate::compiler::{Compilation, Compiler};
use crate::link::link_module;
use crate::object::ObjectUnwindInfo;
use anyhow::{Context, Result};
use object::File as ObjectFile;
use serde::{Deserialize, Serialize};
use std::ops::Range;
@@ -483,16 +484,13 @@ fn build_code_memory(
obj: &[u8],
module: &Module,
unwind_info: &[ObjectUnwindInfo],
) -> Result<
(
CodeMemory,
(*const u8, usize),
PrimaryMap<DefinedFuncIndex, *mut [VMFunctionBody]>,
Vec<(SignatureIndex, VMTrampoline)>,
),
String,
> {
let obj = ObjectFile::parse(obj).map_err(|_| "Unable to read obj".to_string())?;
) -> Result<(
CodeMemory,
(*const u8, usize),
PrimaryMap<DefinedFuncIndex, *mut [VMFunctionBody]>,
Vec<(SignatureIndex, VMTrampoline)>,
)> {
let obj = ObjectFile::parse(obj).with_context(|| "Unable to read obj")?;
let mut code_memory = CodeMemory::new();

4
crates/jit/src/lib.rs
View File

@@ -27,16 +27,12 @@ mod link;
mod object;
mod unwind;
pub mod native;
pub mod trampoline;
pub use crate::code_memory::CodeMemory;
pub use crate::compiler::{Compilation, CompilationStrategy, Compiler};
pub use crate::instantiate::{
CompilationArtifacts, CompiledModule, ModuleCode, SetupError, SymbolizeContext, TypeTables,
};
pub use crate::link::link_module;
pub use wasmtime_cranelift::{blank_sig, wasmtime_call_conv};
/// Version number of this crate.
pub const VERSION: &str = env!("CARGO_PKG_VERSION");

14
crates/jit/src/native.rs
View File

@@ -1,14 +0,0 @@
#![allow(missing_docs)]
use cranelift_codegen;
pub fn builder() -> cranelift_codegen::isa::Builder {
cranelift_native::builder().expect("host machine is not a supported target")
}
pub fn builder_without_flags() -> cranelift_codegen::isa::Builder {
cranelift_native::builder_with_options(cranelift_codegen::isa::BackendVariant::Any, false)
.expect("host machine is not a supported target")
}
pub use cranelift_codegen::isa::lookup;

15
crates/jit/src/object.rs
View File

@@ -1,12 +1,11 @@
//! Object file generation.
use super::trampoline::build_trampoline;
use cranelift_frontend::FunctionBuilderContext;
use crate::Compiler;
use object::write::Object;
use serde::{Deserialize, Serialize};
use std::collections::BTreeSet;
use wasmtime_debug::DwarfSection;
use wasmtime_environ::isa::{unwind::UnwindInfo, TargetIsa};
use wasmtime_environ::isa::unwind::UnwindInfo;
use wasmtime_environ::wasm::{FuncIndex, SignatureIndex};
use wasmtime_environ::{CompiledFunctions, ModuleTranslation, TypeTables};
use wasmtime_obj::{ObjectBuilder, ObjectBuilderTarget};
@@ -22,7 +21,7 @@ pub enum ObjectUnwindInfo {
// Builds ELF image from the module `Compilation`.
pub(crate) fn build_object(
isa: &dyn TargetIsa,
compiler: &Compiler,
translation: &ModuleTranslation,
types: &TypeTables,
funcs: &CompiledFunctions,
@@ -50,10 +49,10 @@ pub(crate) fn build_object(
})
.collect::<BTreeSet<_>>();
let mut trampolines = Vec::with_capacity(signatures.len());
let mut cx = FunctionBuilderContext::new();
for i in signatures {
let native_sig = wasmtime_cranelift::indirect_signature(isa, &types, i);
let func = build_trampoline(isa, &mut cx, &native_sig, std::mem::size_of::<u128>())?;
let func = compiler
.compiler()
.host_to_wasm_trampoline(compiler.isa(), &types.wasm_signatures[i])?;
// Preserve trampoline function unwind info.
if let Some(info) = &func.unwind_info {
unwind_info.push(ObjectUnwindInfo::Trampoline(i, info.clone()))
@@ -61,7 +60,7 @@ pub(crate) fn build_object(
trampolines.push((i, func));
}
let target = ObjectBuilderTarget::new(isa.triple().architecture)?;
let target = ObjectBuilderTarget::new(compiler.isa().triple().architecture)?;
let mut builder = ObjectBuilder::new(target, &translation.module, funcs);
builder
.set_code_alignment(CODE_SECTION_ALIGNMENT)

217
crates/jit/src/trampoline.rs
View File

@@ -1,217 +0,0 @@
#![allow(missing_docs)]
use crate::code_memory::CodeMemory;
use crate::instantiate::SetupError;
use cranelift_codegen::ir::InstBuilder;
use cranelift_codegen::isa::TargetIsa;
use wasmtime_environ::{CompileError, CompiledFunction, Relocation, RelocationTarget};
use wasmtime_runtime::{InstantiationError, VMFunctionBody, VMTrampoline};
pub mod ir {
pub(super) use cranelift_codegen::ir::{
AbiParam, ConstantOffset, JumpTable, Signature, SourceLoc,
};
pub use cranelift_codegen::ir::{
ExternalName, Function, InstBuilder, MemFlags, StackSlotData, StackSlotKind,
};
}
pub use cranelift_codegen::print_errors::pretty_error;
pub use cranelift_codegen::Context;
pub use cranelift_frontend::{FunctionBuilder, FunctionBuilderContext};
pub mod binemit {
pub use cranelift_codegen::binemit::NullTrapSink;
pub(super) use cranelift_codegen::binemit::{Addend, Reloc, RelocSink};
pub use cranelift_codegen::binemit::{CodeOffset, NullStackMapSink, TrapSink};
}
/// Create a trampoline for invoking a function.
pub fn make_trampoline(
isa: &dyn TargetIsa,
code_memory: &mut CodeMemory,
fn_builder_ctx: &mut FunctionBuilderContext,
signature: &ir::Signature,
value_size: usize,
) -> Result<VMTrampoline, SetupError> {
let compiled_function = build_trampoline(isa, fn_builder_ctx, signature, value_size)?;
assert!(compiled_function.relocations.is_empty());
let ptr = code_memory
.allocate_for_function(&compiled_function)
.map_err(|message| {
SetupError::Instantiate(InstantiationError::Resource(anyhow::anyhow!(message)))
})?
.as_ptr();
Ok(unsafe { std::mem::transmute::<*const VMFunctionBody, VMTrampoline>(ptr) })
}
pub(crate) fn build_trampoline(
isa: &dyn TargetIsa,
fn_builder_ctx: &mut FunctionBuilderContext,
signature: &ir::Signature,
value_size: usize,
) -> Result<CompiledFunction, SetupError> {
let pointer_type = isa.pointer_type();
let mut wrapper_sig =
wasmtime_cranelift::blank_sig(isa, wasmtime_cranelift::wasmtime_call_conv(isa));
// Add the `callee_address` parameter.
wrapper_sig.params.push(ir::AbiParam::new(pointer_type));
// Add the `values_vec` parameter.
wrapper_sig.params.push(ir::AbiParam::new(pointer_type));
let mut context = Context::new();
context.func = ir::Function::with_name_signature(ir::ExternalName::user(0, 0), wrapper_sig);
{
let mut builder = FunctionBuilder::new(&mut context.func, fn_builder_ctx);
let block0 = builder.create_block();
builder.append_block_params_for_function_params(block0);
builder.switch_to_block(block0);
builder.seal_block(block0);
let (vmctx_ptr_val, caller_vmctx_ptr_val, callee_value, values_vec_ptr_val) = {
let params = builder.func.dfg.block_params(block0);
(params[0], params[1], params[2], params[3])
};
// Load the argument values out of `values_vec`.
let mflags = ir::MemFlags::trusted();
let callee_args = signature
.params
.iter()
.enumerate()
.map(|(i, r)| {
match i {
0 => vmctx_ptr_val,
1 => caller_vmctx_ptr_val,
_ =>
// i - 2 because vmctx and caller vmctx aren't passed through `values_vec`.
{
builder.ins().load(
r.value_type,
mflags,
values_vec_ptr_val,
((i - 2) * value_size) as i32,
)
}
}
})
.collect::<Vec<_>>();
let new_sig = builder.import_signature(signature.clone());
let call = builder
.ins()
.call_indirect(new_sig, callee_value, &callee_args);
let results = builder.func.dfg.inst_results(call).to_vec();
// Store the return values into `values_vec`.
let mflags = ir::MemFlags::trusted();
for (i, r) in results.iter().enumerate() {
builder
.ins()
.store(mflags, *r, values_vec_ptr_val, (i * value_size) as i32);
}
builder.ins().return_(&[]);
builder.finalize()
}
let mut code_buf = Vec::new();
let mut reloc_sink = TrampolineRelocSink::default();
let mut trap_sink = binemit::NullTrapSink {};
let mut stack_map_sink = binemit::NullStackMapSink {};
context
.compile_and_emit(
isa,
&mut code_buf,
&mut reloc_sink,
&mut trap_sink,
&mut stack_map_sink,
)
.map_err(|error| {
SetupError::Compile(CompileError::Codegen(pretty_error(
&context.func,
Some(isa),
error,
)))
})?;
let unwind_info = context.create_unwind_info(isa).map_err(|error| {
SetupError::Compile(CompileError::Codegen(pretty_error(
&context.func,
Some(isa),
error,
)))
})?;
Ok(CompiledFunction {
body: code_buf,
jt_offsets: context.func.jt_offsets,
unwind_info,
relocations: reloc_sink.relocs,
stack_maps: Default::default(),
stack_slots: Default::default(),
traps: Default::default(),
value_labels_ranges: Default::default(),
address_map: Default::default(),
})
}
/// We don't expect trampoline compilation to produce many relocations, so
/// this `RelocSink` just asserts that it doesn't recieve most of them, but
/// handles libcall ones.
#[derive(Default)]
pub struct TrampolineRelocSink {
relocs: Vec<Relocation>,
}
impl TrampolineRelocSink {
/// Returns collected relocations.
pub fn relocs(&self) -> &[Relocation] {
&self.relocs
}
}
impl binemit::RelocSink for TrampolineRelocSink {
fn reloc_external(
&mut self,
offset: binemit::CodeOffset,
_srcloc: ir::SourceLoc,
reloc: binemit::Reloc,
name: &ir::ExternalName,
addend: binemit::Addend,
) {
let reloc_target = if let ir::ExternalName::LibCall(libcall) = *name {
RelocationTarget::LibCall(libcall)
} else {
panic!("unrecognized external name")
};
self.relocs.push(Relocation {
reloc,
reloc_target,
offset,
addend,
});
}
fn reloc_constant(
&mut self,
_code_offset: binemit::CodeOffset,
_reloc: binemit::Reloc,
_constant_offset: ir::ConstantOffset,
) {
panic!("trampoline compilation should not produce constant relocs");
}
fn reloc_jt(
&mut self,
_offset: binemit::CodeOffset,
_reloc: binemit::Reloc,
_jt: ir::JumpTable,
) {
panic!("trampoline compilation should not produce jump table relocs");
}
}

2
crates/jit/src/unwind/systemv.rs
View File

@@ -1,11 +1,11 @@
//! Module for System V ABI unwind registry.
use anyhow::{bail, Result};
use cranelift_codegen::isa::{unwind::UnwindInfo, TargetIsa};
use gimli::{
write::{Address, EhFrame, EndianVec, FrameTable, Writer},
RunTimeEndian,
};
use wasmtime_environ::isa::{unwind::UnwindInfo, TargetIsa};
/// Represents a registry of function unwind information for System V ABI.
pub struct UnwindRegistry {

2
crates/jit/src/unwind/winx64.rs
View File

@@ -1,7 +1,7 @@
//! Module for Windows x64 ABI unwind registry.
use anyhow::{bail, Result};
use cranelift_codegen::isa::{unwind::UnwindInfo, TargetIsa};
use wasmtime_environ::isa::{unwind::UnwindInfo, TargetIsa};
use winapi::um::winnt;
/// Represents a registry of function unwind information for Windows x64 ABI.