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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 memory reads and writes.
// This can be useful in building tools that analyze memory access behaviour.
//
// Before:
// (i32.load8_s align=1 offset=2 (i32.const 3))
//
// After:
// (call $load_val_i32
// (i32.const n) // ID
// (i32.load8_s align=1 offset=2
// (call $load_ptr
// (i32.const n) // ID
// (i32.const 1) // bytes
// (i32.const 2) // offset
// (i32.const 3) // address
// )
// )
// )
// Stores: store(id, bytes, offset, address) => address
//
// Before:
// (i32.store8 align=1 offset=2 (i32.const 3) (i32.const 4))
//
// After:
// (i32.store16 align=1 offset=2
// (call $store_ptr
// (i32.const n) // ID
// (i32.const 1) // bytes
// (i32.const 2) // offset
// (i32.const 3) // address
// )
// (call $store_val_i32
// (i32.const n) // ID
// (i32.const 4)
// )
// )
#include "asm_v_wasm.h"
#include "asmjs/shared-constants.h"
#include "shared-constants.h"
#include <pass.h>
#include <wasm-builder.h>
#include <wasm.h>
namespace wasm {
static Name load_ptr("load_ptr");
static Name load_val_i32("load_val_i32");
static Name load_val_i64("load_val_i64");
static Name load_val_f32("load_val_f32");
static Name load_val_f64("load_val_f64");
static Name store_ptr("store_ptr");
static Name store_val_i32("store_val_i32");
static Name store_val_i64("store_val_i64");
static Name store_val_f32("store_val_f32");
static Name store_val_f64("store_val_f64");
// TODO: Add support for atomicRMW/cmpxchg
struct InstrumentMemory : public WalkerPass<PostWalker<InstrumentMemory>> {
void visitLoad(Load* curr) {
id++;
Builder builder(*getModule());
curr->ptr =
builder.makeCall(load_ptr,
{builder.makeConst(Literal(int32_t(id))),
builder.makeConst(Literal(int32_t(curr->bytes))),
builder.makeConst(Literal(int32_t(curr->offset.addr))),
curr->ptr},
i32);
Name target;
switch (curr->type) {
case i32:
target = load_val_i32;
break;
case i64:
target = load_val_i64;
break;
case f32:
target = load_val_f32;
break;
case f64:
target = load_val_f64;
break;
default:
return; // TODO: other types, unreachable, etc.
}
replaceCurrent(builder.makeCall(
target, {builder.makeConst(Literal(int32_t(id))), curr}, curr->type));
}
void visitStore(Store* curr) {
id++;
Builder builder(*getModule());
curr->ptr =
builder.makeCall(store_ptr,
{builder.makeConst(Literal(int32_t(id))),
builder.makeConst(Literal(int32_t(curr->bytes))),
builder.makeConst(Literal(int32_t(curr->offset.addr))),
curr->ptr},
i32);
Name target;
switch (curr->value->type) {
case i32:
target = store_val_i32;
break;
case i64:
target = store_val_i64;
break;
case f32:
target = store_val_f32;
break;
case f64:
target = store_val_f64;
break;
default:
return; // TODO: other types, unreachable, etc.
}
curr->value =
builder.makeCall(target,
{builder.makeConst(Literal(int32_t(id))), curr->value},
curr->value->type);
}
void visitModule(Module* curr) {
addImport(
curr, load_ptr, {Type::i32, Type::i32, Type::i32, Type::i32}, Type::i32);
addImport(curr, load_val_i32, {Type::i32, Type::i32}, Type::i32);
addImport(curr, load_val_i64, {Type::i32, Type::i64}, Type::i64);
addImport(curr, load_val_f32, {Type::i32, Type::f32}, Type::f32);
addImport(curr, load_val_f64, {Type::i32, Type::f64}, Type::f64);
addImport(
curr, store_ptr, {Type::i32, Type::i32, Type::i32, Type::i32}, Type::i32);
addImport(curr, store_val_i32, {Type::i32, Type::i32}, Type::i32);
addImport(curr, store_val_i64, {Type::i32, Type::i64}, Type::i64);
addImport(curr, store_val_f32, {Type::i32, Type::f32}, Type::f32);
addImport(curr, store_val_f64, {Type::i32, Type::f64}, Type::f64);
}
private:
Index id;
void addImport(Module* curr, Name name, Type params, Type results) {
auto import = new Function;
import->name = name;
import->module = ENV;
import->base = name;
import->sig = Signature(params, results);
curr->addFunction(import);
}
};
Pass* createInstrumentMemoryPass() { return new InstrumentMemory(); }
} // namespace wasm
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