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/*
* Copyright 2017 WebAssembly Community Group participants
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
//
// Instruments the build with code to intercept all local reads and writes.
//
// gets:
//
// Before:
// (local.get $x)
//
// After:
// (call $get_TYPE
// (i32.const n) // call id
// (i32.const n) // local id
// (local.get $x)
// )
//
// sets:
//
// Before:
// (local.set $x (i32.const 1))
//
// After:
// (local.set $x
// (call $set_TYPE
// (i32.const n) // call id
// (i32.const n) // local id
// (i32.const 1) // value
// )
// )
#include "asmjs/shared-constants.h"
#include "shared-constants.h"
#include <pass.h>
#include <wasm-builder.h>
#include <wasm.h>
namespace wasm {
Name get_i32("get_i32");
Name get_i64("get_i64");
Name get_f32("get_f32");
Name get_f64("get_f64");
Name get_v128("get_v128");
Name get_funcref("get_funcref");
Name get_externref("get_externref");
Name set_i32("set_i32");
Name set_i64("set_i64");
Name set_f32("set_f32");
Name set_f64("set_f64");
Name set_v128("set_v128");
Name set_funcref("set_funcref");
Name set_externref("set_externref");
struct InstrumentLocals : public WalkerPass<PostWalker<InstrumentLocals>> {
// Adds calls to new imports.
bool addsEffects() override { return true; }
void visitLocalGet(LocalGet* curr) {
Builder builder(*getModule());
Name import;
if (curr->type.isRef()) {
auto heapType = curr->type.getHeapType();
if (heapType == HeapType::func && curr->type.isNullable()) {
import = get_funcref;
} else if (heapType == HeapType::ext && curr->type.isNullable()) {
import = get_externref;
} else {
WASM_UNREACHABLE("TODO: general reference types");
}
} else {
TODO_SINGLE_COMPOUND(curr->type);
switch (curr->type.getBasic()) {
case Type::i32:
import = get_i32;
break;
case Type::i64:
return; // TODO
case Type::f32:
import = get_f32;
break;
case Type::f64:
import = get_f64;
break;
case Type::v128:
import = get_v128;
break;
case Type::none:
case Type::unreachable:
WASM_UNREACHABLE("unexpected type");
}
}
replaceCurrent(builder.makeCall(import,
{builder.makeConst(int32_t(id++)),
builder.makeConst(int32_t(curr->index)),
curr},
curr->type));
}
void visitLocalSet(LocalSet* curr) {
// We don't instrument pop instructions. They are automatically deleted when
// writing binary and generated when reading binary, so they don't work with
// local set/get instrumentation.
if (curr->value->is<Pop>()) {
return;
}
Builder builder(*getModule());
Name import;
auto type = curr->value->type;
if (type.isFunction() && type.getHeapType() != HeapType::func) {
// FIXME: support typed function references
return;
}
if (type.isRef()) {
auto heapType = type.getHeapType();
if (heapType == HeapType::func && type.isNullable()) {
import = set_funcref;
} else if (heapType == HeapType::ext && type.isNullable()) {
import = set_externref;
} else {
WASM_UNREACHABLE("TODO: general reference types");
}
} else {
TODO_SINGLE_COMPOUND(curr->value->type);
switch (type.getBasic()) {
case Type::i32:
import = set_i32;
break;
case Type::i64:
return; // TODO
case Type::f32:
import = set_f32;
break;
case Type::f64:
import = set_f64;
break;
case Type::v128:
import = set_v128;
break;
case Type::unreachable:
return; // nothing to do here
case Type::none:
WASM_UNREACHABLE("unexpected type");
}
}
curr->value = builder.makeCall(import,
{builder.makeConst(int32_t(id++)),
builder.makeConst(int32_t(curr->index)),
curr->value},
curr->value->type);
}
void visitModule(Module* curr) {
addImport(curr, get_i32, {Type::i32, Type::i32, Type::i32}, Type::i32);
addImport(curr, get_i64, {Type::i32, Type::i32, Type::i64}, Type::i64);
addImport(curr, get_f32, {Type::i32, Type::i32, Type::f32}, Type::f32);
addImport(curr, get_f64, {Type::i32, Type::i32, Type::f64}, Type::f64);
addImport(curr, set_i32, {Type::i32, Type::i32, Type::i32}, Type::i32);
addImport(curr, set_i64, {Type::i32, Type::i32, Type::i64}, Type::i64);
addImport(curr, set_f32, {Type::i32, Type::i32, Type::f32}, Type::f32);
addImport(curr, set_f64, {Type::i32, Type::i32, Type::f64}, Type::f64);
if (curr->features.hasReferenceTypes()) {
Type func = Type(HeapType::func, Nullable);
Type ext = Type(HeapType::ext, Nullable);
addImport(curr, get_funcref, {Type::i32, Type::i32, func}, func);
addImport(curr, set_funcref, {Type::i32, Type::i32, func}, func);
addImport(curr, get_externref, {Type::i32, Type::i32, ext}, ext);
addImport(curr, set_externref, {Type::i32, Type::i32, ext}, ext);
}
if (curr->features.hasSIMD()) {
addImport(curr, get_v128, {Type::i32, Type::i32, Type::v128}, Type::v128);
addImport(curr, set_v128, {Type::i32, Type::i32, Type::v128}, Type::v128);
}
}
private:
Index id = 0;
void addImport(Module* wasm, Name name, Type params, Type results) {
auto import = Builder::makeFunction(name, Signature(params, results), {});
import->module = ENV;
import->base = name;
wasm->addFunction(std::move(import));
}
};
Pass* createInstrumentLocalsPass() { return new InstrumentLocals(); }
} // namespace wasm
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