wasmer/lib/clif-backend/src/func_env.rs
2019-01-16 17:59:12 -08:00

608 lines
24 KiB
Rust

use crate::{module::Converter, module_env::ModuleEnv};
use cranelift_codegen::{
cursor::FuncCursor,
ir::{self, InstBuilder},
isa,
};
use cranelift_entity::EntityRef;
use cranelift_wasm::{self, FuncEnvironment, ModuleEnvironment};
use wasmer_runtime::{
memory::LinearMemory,
structures::TypedIndex,
types::{FuncIndex, GlobalIndex, LocalOrImport, MemoryIndex, TableIndex},
vm,
};
pub struct FuncEnv<'env, 'module, 'isa> {
env: &'env ModuleEnv<'module, 'isa>,
}
impl<'env, 'module, 'isa> FuncEnv<'env, 'module, 'isa> {
pub fn new(env: &'env ModuleEnv<'module, 'isa>) -> Self {
Self { env }
}
/// Creates a signature with VMContext as the last param
pub fn generate_signature(&self, sig_index: cranelift_wasm::SignatureIndex) -> ir::Signature {
// Get signature
let mut signature = self.env.signatures[Converter(sig_index).into()].clone();
// Add the vmctx parameter type to it
signature.params.push(ir::AbiParam::special(
self.pointer_type(),
ir::ArgumentPurpose::VMContext,
));
// Return signature
signature
}
}
impl<'env, 'module, 'isa> FuncEnvironment for FuncEnv<'env, 'module, 'isa> {
/// Gets configuration information needed for compiling functions
fn target_config(&self) -> isa::TargetFrontendConfig {
self.env.target_config()
}
/// Gets native pointers types.
///
/// `I64` on 64-bit arch; `I32` on 32-bit arch.
fn pointer_type(&self) -> ir::Type {
ir::Type::int(u16::from(self.target_config().pointer_bits())).unwrap()
}
/// Gets the size of a native pointer in bytes.
fn pointer_bytes(&self) -> u8 {
self.target_config().pointer_bytes()
}
/// Sets up the necessary preamble definitions in `func` to access the global identified
/// by `index`.
///
/// The index space covers both imported and locally declared globals.
fn make_global(
&mut self,
func: &mut ir::Function,
clif_global_index: cranelift_wasm::GlobalIndex,
) -> cranelift_wasm::GlobalVariable {
let global_index: GlobalIndex = Converter(clif_global_index).into();
// Create VMContext value.
let vmctx = func.create_global_value(ir::GlobalValueData::VMContext);
let ptr_type = self.pointer_type();
match global_index.local_or_import(self.env.module) {
LocalOrImport::Local(local_global_index) => {
let globals_base_addr = func.create_global_value(ir::GlobalValueData::Load {
base: vmctx,
offset: (vm::Ctx::offset_globals() as i32).into(),
global_type: self.pointer_type(),
readonly: true,
});
let offset = local_global_index.index() * vm::LocalGlobal::size() as usize;
let local_global_addr = func.create_global_value(ir::GlobalValueData::IAddImm {
base: globals_base_addr,
offset: (offset as i64).into(),
global_type: ptr_type,
});
// Create global variable based on the data above.
cranelift_wasm::GlobalVariable::Memory {
gv: local_global_addr,
offset: (vm::LocalGlobal::offset_data() as i32).into(),
ty: self.env.get_global(clif_global_index).ty,
}
}
LocalOrImport::Import(imported_global_index) => {
let imported_globals_base_addr =
func.create_global_value(ir::GlobalValueData::Load {
base: vmctx,
offset: (vm::Ctx::offset_imported_globals() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let offset = imported_global_index.index() * vm::ImportedGlobal::size() as usize;
let imported_global_addr = func.create_global_value(ir::GlobalValueData::IAddImm {
base: imported_globals_base_addr,
offset: (offset as i64).into(),
global_type: ptr_type,
});
let local_global_addr = func.create_global_value(ir::GlobalValueData::Load {
base: imported_global_addr,
offset: (vm::ImportedGlobal::offset_global() as i32).into(),
global_type: ptr_type,
readonly: true,
});
cranelift_wasm::GlobalVariable::Memory {
gv: local_global_addr,
offset: (vm::LocalGlobal::offset_data() as i32).into(),
ty: self.env.get_global(clif_global_index).ty,
}
}
}
}
/// Sets up the necessary preamble definitions in `func` to access the linear memory identified
/// by `index`.
///
/// The index space covers both imported and locally declared memories.
fn make_heap(
&mut self,
func: &mut ir::Function,
clif_mem_index: cranelift_wasm::MemoryIndex,
) -> ir::Heap {
let mem_index: MemoryIndex = Converter(clif_mem_index).into();
// Create VMContext value.
let vmctx = func.create_global_value(ir::GlobalValueData::VMContext);
let ptr_type = self.pointer_type();
match mem_index.local_or_import(self.env.module) {
LocalOrImport::Local(local_mem_index) => {
let memories_base_addr = func.create_global_value(ir::GlobalValueData::Load {
base: vmctx,
offset: (vm::Ctx::offset_memories() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let memory_offset = local_mem_index.index() * vm::LocalMemory::size() as usize;
let memory_struct_addr = func.create_global_value(ir::GlobalValueData::IAddImm {
base: memories_base_addr,
offset: (memory_offset as i64).into(),
global_type: ptr_type,
});
let memory_base_addr = func.create_global_value(ir::GlobalValueData::Load {
base: memory_struct_addr,
offset: (vm::LocalMemory::offset_base() as i32).into(),
global_type: ptr_type,
readonly: true,
});
func.create_heap(ir::HeapData {
base: memory_base_addr,
min_size: (self.env.module.memories[local_mem_index].min as u64).into(),
offset_guard_size: (LinearMemory::DEFAULT_GUARD_SIZE as u64).into(),
style: ir::HeapStyle::Static {
bound: (LinearMemory::DEFAULT_HEAP_SIZE as u64).into(),
},
index_type: ir::types::I32,
})
}
LocalOrImport::Import(imported_mem_index) => {
let imported_memories_base = func.create_global_value(ir::GlobalValueData::Load {
base: vmctx,
offset: (vm::Ctx::offset_imported_memories() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let imported_memory_offset =
imported_mem_index.index() * vm::ImportedMemory::size() as usize;
let imported_memory_struct_addr =
func.create_global_value(ir::GlobalValueData::IAddImm {
base: imported_memories_base,
offset: (imported_memory_offset as i64).into(),
global_type: ptr_type,
});
let local_memory_struct_addr =
func.create_global_value(ir::GlobalValueData::Load {
base: imported_memory_struct_addr,
offset: (vm::ImportedMemory::offset_memory() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let local_memory_base = func.create_global_value(ir::GlobalValueData::Load {
base: local_memory_struct_addr,
offset: (vm::LocalMemory::offset_base() as i32).into(),
global_type: ptr_type,
readonly: true,
});
func.create_heap(ir::HeapData {
base: local_memory_base,
min_size: (self.env.module.imported_memories[imported_mem_index].1.min as u64)
.into(),
offset_guard_size: (LinearMemory::DEFAULT_GUARD_SIZE as u64).into(),
style: ir::HeapStyle::Static {
bound: (LinearMemory::DEFAULT_HEAP_SIZE as u64).into(),
},
index_type: ir::types::I32,
})
}
}
}
/// Sets up the necessary preamble definitions in `func` to access the table identified
/// by `index`.
///
/// The index space covers both imported and locally declared tables.
fn make_table(
&mut self,
func: &mut ir::Function,
clif_table_index: cranelift_wasm::TableIndex,
) -> ir::Table {
let table_index: TableIndex = Converter(clif_table_index).into();
// Create VMContext value.
let vmctx = func.create_global_value(ir::GlobalValueData::VMContext);
let ptr_type = self.pointer_type();
match table_index.local_or_import(self.env.module) {
LocalOrImport::Local(local_table_index) => {
let tables_base = func.create_global_value(ir::GlobalValueData::Load {
base: vmctx,
offset: (vm::Ctx::offset_tables() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let table_struct_offset =
local_table_index.index() * vm::LocalTable::size() as usize;
let table_struct_addr = func.create_global_value(ir::GlobalValueData::IAddImm {
base: tables_base,
offset: (table_struct_offset as i64).into(),
global_type: ptr_type,
});
let table_base = func.create_global_value(ir::GlobalValueData::Load {
base: table_struct_addr,
offset: (vm::LocalTable::offset_base() as i32).into(),
global_type: ptr_type,
// we will support growing tables, so this cannot be readonly.
readonly: false,
});
let table_bound = func.create_global_value(ir::GlobalValueData::Load {
base: table_struct_addr,
offset: (vm::LocalTable::offset_current_elements() as i32).into(),
// the number of elements in a table will always fit in an `i32`.
global_type: ir::types::I32,
readonly: false,
});
func.create_table(ir::TableData {
base_gv: table_base,
min_size: (self.env.module.tables[local_table_index].min as u64).into(),
bound_gv: table_bound,
element_size: (vm::Anyfunc::size() as u64).into(),
index_type: ir::types::I32,
})
}
LocalOrImport::Import(imported_table_index) => {
let imported_tables_base = func.create_global_value(ir::GlobalValueData::Load {
base: vmctx,
offset: (vm::Ctx::offset_imported_memories() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let imported_table_struct_offset =
imported_table_index.index() * vm::ImportedTable::size() as usize;
let imported_table_struct_addr =
func.create_global_value(ir::GlobalValueData::IAddImm {
base: imported_tables_base,
offset: (imported_table_struct_offset as i64).into(),
global_type: ptr_type,
});
let local_table_struct_addr = func.create_global_value(ir::GlobalValueData::Load {
base: imported_table_struct_addr,
offset: (vm::ImportedTable::offset_table() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let local_table_base = func.create_global_value(ir::GlobalValueData::Load {
base: local_table_struct_addr,
offset: (vm::LocalTable::offset_base() as i32).into(),
global_type: ptr_type,
readonly: false,
});
let local_table_bound = func.create_global_value(ir::GlobalValueData::Load {
base: local_table_struct_addr,
offset: (vm::LocalTable::offset_current_elements() as i32).into(),
global_type: ir::types::I32,
readonly: false,
});
func.create_table(ir::TableData {
base_gv: local_table_base,
min_size: (self.env.module.imported_tables[imported_table_index].1.min as u64)
.into(),
bound_gv: local_table_bound,
element_size: (vm::Anyfunc::size() as u64).into(),
index_type: ir::types::I32,
})
}
}
}
/// Sets up a signature definition in `func`'s preamble.
///
/// Signature may contain additional argument, but arguments marked as ArgumentPurpose::Normal`
/// must correspond to the arguments in the wasm signature
fn make_indirect_sig(
&mut self,
func: &mut ir::Function,
index: cranelift_wasm::SignatureIndex,
) -> ir::SigRef {
// Create a signature reference out of specified signature (with VMContext param added).
func.import_signature(self.generate_signature(index))
}
/// Sets up an external function definition in the preamble of `func` that can be used to
/// directly call the function `index`.
///
/// The index space covers both imported functions and functions defined in the current module.
fn make_direct_func(
&mut self,
func: &mut ir::Function,
func_index: cranelift_wasm::FuncIndex,
) -> ir::FuncRef {
// Get signature of function.
let signature_index = self.env.get_func_type(func_index);
// Create a signature reference from specified signature (with VMContext param added).
let signature = func.import_signature(self.generate_signature(signature_index));
// Get name of function.
let name = ir::ExternalName::user(0, func_index.as_u32());
// Create function reference from fuction data.
func.import_function(ir::ExtFuncData {
name,
signature,
colocated: false,
})
}
/// Generates an indirect call IR with `callee` and `call_args`.
///
/// Inserts instructions at `pos` to the function `callee` in the table
/// `table_index` with WebAssembly signature `sig_index`
#[cfg_attr(feature = "cargo-clippy", allow(clippy::too_many_arguments))]
fn translate_call_indirect(
&mut self,
mut pos: FuncCursor,
_table_index: cranelift_wasm::TableIndex,
table: ir::Table,
sig_index: cranelift_wasm::SignatureIndex,
sig_ref: ir::SigRef,
callee: ir::Value,
call_args: &[ir::Value],
) -> cranelift_wasm::WasmResult<ir::Inst> {
// Get the pointer type based on machine's pointer size.
let ptr_type = self.pointer_type();
// The `callee` value is an index into a table of Anyfunc structures.
let entry_addr = pos.ins().table_addr(ptr_type, table, callee, 0);
let mflags = ir::MemFlags::trusted();
let func_ptr = pos.ins().load(
ptr_type,
mflags,
entry_addr,
vm::Anyfunc::offset_func() as i32,
);
let vmctx_ptr = pos.ins().load(
ptr_type,
mflags,
entry_addr,
vm::Anyfunc::offset_vmctx() as i32,
);
let found_sig = pos.ins().load(
ir::types::I32,
mflags,
entry_addr,
vm::Anyfunc::offset_sig_id() as i32,
);
pos.ins().trapz(func_ptr, ir::TrapCode::IndirectCallToNull);
let deduplicated_sig_index = self
.env
.module
.sig_registry
.lookup_deduplicated_sigindex(Converter(sig_index).into());
let expected_sig = pos
.ins()
.iconst(ir::types::I32, deduplicated_sig_index.index() as i64);
let not_equal_flags = pos.ins().ifcmp(found_sig, expected_sig);
pos.ins().trapif(
ir::condcodes::IntCC::NotEqual,
not_equal_flags,
ir::TrapCode::BadSignature,
);
// Build a value list for the indirect call instruction containing the call_args
// and the vmctx parameter.
let mut args = Vec::with_capacity(call_args.len() + 1);
args.extend(call_args.iter().cloned());
args.push(vmctx_ptr);
Ok(pos.ins().call_indirect(sig_ref, func_ptr, &args))
}
/// Generates a call IR with `callee` and `call_args` and inserts it at `pos`
/// TODO: add support for imported functions
fn translate_call(
&mut self,
mut pos: FuncCursor,
clif_callee_index: cranelift_wasm::FuncIndex,
callee: ir::FuncRef,
call_args: &[ir::Value],
) -> cranelift_wasm::WasmResult<ir::Inst> {
let callee_index: FuncIndex = Converter(clif_callee_index).into();
match callee_index.local_or_import(self.env.module) {
LocalOrImport::Local(_) => {
// this is an internal function
let vmctx = pos
.func
.special_param(ir::ArgumentPurpose::VMContext)
.expect("missing vmctx parameter");
let mut args = Vec::with_capacity(call_args.len() + 1);
args.extend(call_args.iter().cloned());
args.push(vmctx);
Ok(pos.ins().call(callee, &args))
}
LocalOrImport::Import(imported_func_index) => {
let ptr_type = self.pointer_type();
// this is an imported function
let vmctx = pos.func.create_global_value(ir::GlobalValueData::VMContext);
let imported_funcs = pos.func.create_global_value(ir::GlobalValueData::Load {
base: vmctx,
offset: (vm::Ctx::offset_imported_funcs() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let imported_func_offset =
imported_func_index.index() * vm::ImportedFunc::size() as usize;
let imported_func_struct_addr =
pos.func.create_global_value(ir::GlobalValueData::IAddImm {
base: imported_funcs,
offset: (imported_func_offset as i64).into(),
global_type: ptr_type,
});
let imported_func_addr = pos.func.create_global_value(ir::GlobalValueData::Load {
base: imported_func_struct_addr,
offset: (vm::ImportedFunc::offset_func() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let imported_vmctx_addr = pos.func.create_global_value(ir::GlobalValueData::Load {
base: imported_func_struct_addr,
offset: (vm::ImportedFunc::offset_vmctx() as i32).into(),
global_type: ptr_type,
readonly: true,
});
let imported_func_addr = pos.ins().global_value(ptr_type, imported_func_addr);
let imported_vmctx_addr = pos.ins().global_value(ptr_type, imported_vmctx_addr);
let sig_ref = pos.func.dfg.ext_funcs[callee].signature;
let mut args = Vec::with_capacity(call_args.len() + 1);
args.extend(call_args.iter().cloned());
args.push(imported_vmctx_addr);
Ok(pos
.ins()
.call_indirect(sig_ref, imported_func_addr, &args[..]))
}
}
}
/// Generates code corresponding to wasm `memory.grow`.
///
/// `index` refers to the linear memory to query.
///
/// `heap` refers to the IR generated by `make_heap`.
///
/// `val` refers the value to grow the memory by.
fn translate_memory_grow(
&mut self,
mut pos: FuncCursor,
index: cranelift_wasm::MemoryIndex,
_heap: ir::Heap,
val: ir::Value,
) -> cranelift_wasm::WasmResult<ir::Value> {
let signature = pos.func.import_signature(ir::Signature {
call_conv: self.target_config().default_call_conv,
params: vec![
ir::AbiParam::new(ir::types::I32),
ir::AbiParam::new(ir::types::I32),
ir::AbiParam::special(self.pointer_type(), ir::ArgumentPurpose::VMContext),
],
returns: vec![ir::AbiParam::new(ir::types::I32)],
});
let grow_mem_func = pos.func.import_function(ir::ExtFuncData {
// `ir::ExternalName` for static_grow_memory`
name: ir::ExternalName::user(1, 0),
signature,
colocated: false,
});
// Create a memory index value.
let memory_index = pos.ins().iconst(ir::types::I32, index.index() as i64);
// Create a VMContext value.
let vmctx = pos
.func
.special_param(ir::ArgumentPurpose::VMContext)
.expect("missing vmctx parameter");
// Insert call instructions for `grow_memory`.
let call_inst = pos.ins().call(grow_mem_func, &[memory_index, val, vmctx]);
// Return value.
Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
}
/// Generates code corresponding to wasm `memory.size`.
///
/// `index` refers to the linear memory to query.
///
/// `heap` refers to the IR generated by `make_heap`.
fn translate_memory_size(
&mut self,
mut pos: FuncCursor,
index: cranelift_wasm::MemoryIndex,
_heap: ir::Heap,
) -> cranelift_wasm::WasmResult<ir::Value> {
let signature = pos.func.import_signature(ir::Signature {
call_conv: self.target_config().default_call_conv,
params: vec![
ir::AbiParam::new(ir::types::I32),
ir::AbiParam::special(self.pointer_type(), ir::ArgumentPurpose::VMContext),
],
returns: vec![ir::AbiParam::new(ir::types::I32)],
});
let size_mem_func = pos.func.import_function(ir::ExtFuncData {
// `ir::ExternalName` for static_grow_memory`
name: ir::ExternalName::user(1, 1),
signature,
colocated: false,
});
// Create a memory index value.
let memory_index = pos.ins().iconst(ir::types::I32, index.index() as i64);
// Create a VMContext value.
let vmctx = pos
.func
.special_param(ir::ArgumentPurpose::VMContext)
.expect("missing vmctx parameter");
// Insert call instructions for `grow_memory`.
let call_inst = pos.ins().call(size_mem_func, &[memory_index, vmctx]);
// Return value.
Ok(*pos.func.dfg.inst_results(call_inst).first().unwrap())
}
}