EVM to eWasm translator.

This commit is contained in:
chriseth 2019-05-09 17:56:25 +02:00
parent 1cc8475309
commit 67f11104c1
9 changed files with 446 additions and 6 deletions

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@ -42,6 +42,8 @@ add_library(yul
backends/evm/EVMMetrics.h
backends/evm/NoOutputAssembly.h
backends/evm/NoOutputAssembly.cpp
backends/wasm/EVMToEWasmTranslator.cpp
backends/wasm/EVMToEWasmTranslator.h
backends/wasm/EWasmCodeTransform.cpp
backends/wasm/EWasmCodeTransform.h
backends/wasm/EWasmObjectCompiler.cpp

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@ -0,0 +1,376 @@
/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* Translates Yul code from EVM dialect to eWasm dialect.
*/
#include <libyul/backends/wasm/EVMToEWasmTranslator.h>
#include <libyul/backends/wasm/WordSizeTransform.h>
#include <libyul/backends/wasm/WasmDialect.h>
#include <libyul/optimiser/ExpressionSplitter.h>
#include <libyul/optimiser/FunctionGrouper.h>
#include <libyul/optimiser/MainFunction.h>
#include <libyul/optimiser/FunctionHoister.h>
#include <libyul/optimiser/Disambiguator.h>
#include <libyul/optimiser/NameDisplacer.h>
#include <libyul/AsmParser.h>
#include <libyul/AsmAnalysis.h>
#include <libyul/AsmAnalysisInfo.h>
#include <libyul/Object.h>
#include <liblangutil/ErrorReporter.h>
#include <liblangutil/Scanner.h>
#include <liblangutil/SourceReferenceFormatter.h>
using namespace std;
using namespace dev;
using namespace yul;
using namespace langutil;
namespace
{
static string const polyfill{R"({
function or_bool(a, b, c, d) -> r {
r := i64.ne(0, i64.or(i64.or(a, b), i64.or(c, d)))
}
// returns a + y + c plus carry value on 64 bit values.
// c should be at most 2
function add_carry(x, y, c) -> r, r_c {
let t := i64.add(x, y)
r := i64.add(t, c)
r_c := i64.or(
i64.lt_u(t, x),
i64.lt_u(r, t)
)
}
function add(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
let carry
r4, carry := add_carry(x4, y4, 0)
r3, carry := add_carry(x3, y3, carry)
r2, carry := add_carry(x2, y2, carry)
r1, carry := add_carry(x1, y1, carry)
}
function bit_negate(x) -> y {
y := i64.xor(x, 0xffffffffffffffff)
}
function sub(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
// x - y = x + (~y + 1)
let carry
r4, carry := add_carry(x4, bit_negate(y4), 1)
r3, carry := add_carry(x3, bit_negate(y3), i64.add(carry, 1))
r2, carry := add_carry(x2, bit_negate(y2), i64.add(carry, 1))
r1, carry := add_carry(x1, bit_negate(y1), i64.add(carry, 1))
}
function split(x) -> hi, lo {
hi := i64.shr_u(x, 32)
lo := i64.and(x, 0xffffffff)
}
// Multiplies two 64 bit values resulting in a 128 bit
// value split into two 64 bit values.
function mul_64x64_128(x, y) -> hi, lo {
let xh, xl := split(x)
let yh, yl := split(y)
let t0 := i64.mul(xl, yl)
let t1 := i64.mul(xh, yl)
let t2 := i64.mul(xl, yh)
let t3 := i64.mul(xh, yh)
let t0h, t0l := split(t0)
let u1 := i64.add(t1, t0h)
let u1h, u1l := split(u1)
let u2 := i64.add(t2, u1l)
lo := i64.or(i64.shl(u2, 32), t0l)
hi := i64.add(t3, i64.add(i64.shr_u(u2, 32), u1h))
}
// Add three 64-bit values plus carry (at most 2).
// Return the sum and the new carry value.
function add3_carry(a, b, c, carr) -> x, carry {
let c1, c2
x, c1 := add_carry(a, b, carr)
x, c2 := add_carry(x, c, 0)
carry := i64.add(c1, c2)
}
// Multiplies two 128 bit values resulting in a 256 bit
// value split into four 64 bit values.
function mul_128x128_256(x1, x2, y1, y2) -> r1, r2, r3, r4 {
let ah, al := mul_64x64_128(x1, y1)
let bh, bl := mul_64x64_128(x1, y2)
let ch, cl := mul_64x64_128(x2, y1)
let dh, dl := mul_64x64_128(x2, y2)
let carry
r4 := dl
r3, carry := add3_carry(bl, cl, dh, 0)
r2, carry := add3_carry(al, bh, ch, carry)
r1 := i64.add(ah, carry)
}
function mul(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
}
function div(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {}
function mod(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {}
function smod(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {}
function exp(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {}
function byte(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
if i64.eqz(i64.or(i64.or(x1, x2), x3)) {
let component
switch i64.div_u(x4, 8)
case 0 { component := y1 }
case 1 { component := y2 }
case 2 { component := y3 }
case 3 { component := y4 }
x4 := i64.mul(i64.rem_u(x4, 8), 8)
r4 := i64.shr_u(component, i64.sub(56, x4))
r4 := i64.and(0xff, r4)
}
}
function xor(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
r1 := i64.xor(x1, y1)
r2 := i64.xor(x2, y2)
r3 := i64.xor(x3, y3)
r4 := i64.xor(x4, y4)
}
function or(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
r1 := i64.or(x1, y1)
r2 := i64.or(x2, y2)
r3 := i64.or(x3, y3)
r4 := i64.or(x4, y4)
}
function and(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
r1 := i64.and(x1, y1)
r2 := i64.and(x2, y2)
r3 := i64.and(x3, y3)
r4 := i64.and(x4, y4)
}
function not(x1, x2, x3, x4) -> r1, r2, r3, r4 {
let mask := 0xffffffffffffffff
r1, r2, r3, r4 := xor(x1, x2, x3, x4, mask, mask, mask, mask)
}
function iszero(x1, x2, x3, x4) -> r1, r2, r3, r4 {
r4 := i64.eqz(i64.or(i64.or(x1, x2), i64.or(x3, x4)))
}
function eq(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
if i64.eq(x1, y1) {
if i64.eq(x2, y2) {
if i64.eq(x3, y3) {
if i64.eq(x4, y4) {
r4 := 1
}
}
}
}
}
// TODO
function lt(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function gt(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function slt(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function sgt(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function shl(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function shr(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function sar(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function addmod(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function mulmod(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function signextend(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function keccak256(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {}
function address() -> z1, z2, z3, z4 {}
function balance(x1, x2, x3, x4) -> z1, z2, z3, z4 {}
function origin() -> z1, z2, z3, z4 {}
function caller() -> z1, z2, z3, z4 {}
function callvalue() -> z1, z2, z3, z4 {}
function calldataload(x1, x2, x3, x4) -> z1, z2, z3, z4 {}
function calldatasize() -> z1, z2, z3, z4 {}
function calldatacopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {}
// Needed?
function codesize() -> z1, z2, z3, z4 {}
function codecopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {}
function datacopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {}
function gasprice() -> z1, z2, z3, z4 {}
function extcodesize(x1, x2, x3, x4) -> z1, z2, z3, z4 {}
function extcodehash(x1, x2, x3, x4) -> z1, z2, z3, z4 {}
function extcodecopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {}
function returndatasize() -> z1, z2, z3, z4 {}
function returndatacopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {}
function blockhash(x1, x2, x3, x4) -> z1, z2, z3, z4 {}
function coinbase() -> z1, z2, z3, z4 {}
function timestamp() -> z1, z2, z3, z4 {}
function number() -> z1, z2, z3, z4 {}
function difficulty() -> z1, z2, z3, z4 {}
function gaslimit() -> z1, z2, z3, z4 {}
function pop(x1, x2, x3, x4) {}
function mload(x1, x2, x3, x4) -> z1, z2, z3, z4 {}
function mstore(x1, x2, x3, x4, y1, y2, y3, y4) {}
function mstore8(x1, x2, x3, x4, y1, y2, y3, y4) {}
// Needed?
function msize() -> z1, z2, z3, z4 {}
function sload(x1, x2, x3, x4) -> z1, z2, z3, z4 {}
function sstore(x1, x2, x3, x4, y1, y2, y3, y4) {}
// Needed?
function pc() -> z1, z2, z3, z4 {}
function gas() -> z1, z2, z3, z4 {}
function log0(p1, p2, p3, p4, s1, s2, s3, s4) {}
function log1(
p1, p2, p3, p4, s1, s2, s3, s4,
t11, t12, t13, t14
) {}
function log2(
p1, p2, p3, p4, s1, s2, s3, s4,
t11, t12, t13, t14,
t21, t22, t23, t24
) {}
function log3(
p1, p2, p3, p4, s1, s2, s3, s4,
t11, t12, t13, t14,
t21, t22, t23, t24,
t31, t32, t33, t34
) {}
function log4(
p1, p2, p3, p4, s1, s2, s3, s4,
t11, t12, t13, t14,
t21, t22, t23, t24,
t31, t32, t33, t34,
t41, t42, t43, t44,
) {}
function create(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) -> a1, a2, a3, a4 {}
function call(
a1, a2, a3, a4,
b1, b2, b3, b4,
c1, c2, c3, c4,
d1, d2, d3, d4,
e1, e2, e3, e4,
f1, f2, f3, f4,
g1, g2, g3, g4
) -> x1, x2, x3, x4 {}
function callcode(
a1, a2, a3, a4,
b1, b2, b3, b4,
c1, c2, c3, c4,
d1, d2, d3, d4,
e1, e2, e3, e4,
f1, f2, f3, f4,
g1, g2, g3, g4
) -> x1, x2, x3, x4 {}
function delegatecall(
a1, a2, a3, a4,
b1, b2, b3, b4,
c1, c2, c3, c4,
d1, d2, d3, d4,
e1, e2, e3, e4,
f1, f2, f3, f4
) -> x1, x2, x3, x4 {}
function staticcall(
a1, a2, a3, a4,
b1, b2, b3, b4,
c1, c2, c3, c4,
d1, d2, d3, d4,
e1, e2, e3, e4,
f1, f2, f3, f4
) -> x1, x2, x3, x4 {}
function create2(
a1, a2, a3, a4,
b1, b2, b3, b4,
c1, c2, c3, c4,
d1, d2, d3, d4
) -> x1, x2, x3, x4 {}
function selfdestruct(a1, a2, a3, a4) {}
function return(x1, x2, x3, x4, y1, y2, y3, y4) {}
function revert(x1, x2, x3, x4, y1, y2, y3, y4) {}
function invalid() {
unreachable()
}
})"};
}
Object EVMToEWasmTranslator::run(Object const& _object)
{
if (!m_polyfill)
parsePolyfill();
Block ast = boost::get<Block>(Disambiguator(m_dialect, *_object.analysisInfo)(*_object.code));
NameDispenser nameDispenser{m_dialect, ast};
FunctionHoister{}(ast);
FunctionGrouper{}(ast);
MainFunction{}(ast);
ExpressionSplitter{m_dialect, nameDispenser}(ast);
WordSizeTransform::run(m_dialect, ast, nameDispenser);
NameDisplacer{nameDispenser, m_polyfillFunctions}(ast);
for (auto const& st: m_polyfill->statements)
ast.statements.emplace_back(ASTCopier{}.translate(st));
Object ret;
ret.code = make_shared<Block>(move(ast));
ret.analysisInfo = make_shared<AsmAnalysisInfo>();
ErrorList errors;
ErrorReporter errorReporter(errors);
AsmAnalyzer analyzer(*ret.analysisInfo, errorReporter, boost::none, WasmDialect::instance());
if (!analyzer.analyze(*ret.code))
{
// TODO the errors here are "wrong" because they have invalid source references!
string message;
for (auto const& err: errors)
message += langutil::SourceReferenceFormatter::formatErrorInformation(*err);
yulAssert(false, message);
}
for (auto const& subObjectNode: _object.subObjects)
if (Object const* subObject = dynamic_cast<Object const*>(subObjectNode.get()))
ret.subObjects.push_back(make_shared<Object>(run(*subObject)));
else
ret.subObjects.push_back(make_shared<Data>(dynamic_cast<Data const&>(*subObjectNode)));
ret.subIndexByName = _object.subIndexByName;
return ret;
}
void EVMToEWasmTranslator::parsePolyfill()
{
ErrorList errors;
ErrorReporter errorReporter(errors);
shared_ptr<Scanner> scanner{make_shared<Scanner>(CharStream(polyfill, ""))};
m_polyfill = Parser(errorReporter, WasmDialect::instance()).parse(scanner, false);
if (!errors.empty())
{
string message;
for (auto const& err: errors)
message += langutil::SourceReferenceFormatter::formatErrorInformation(*err);
yulAssert(false, message);
}
m_polyfillFunctions.clear();
for (auto const& statement: m_polyfill->statements)
m_polyfillFunctions.insert(boost::get<FunctionDefinition>(statement).name);
}

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@ -0,0 +1,46 @@
/*
This file is part of solidity.
solidity is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
solidity is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with solidity. If not, see <http://www.gnu.org/licenses/>.
*/
/**
* Translates Yul code from EVM dialect to eWasm dialect.
*/
#pragma once
#include <libyul/AsmDataForward.h>
#include <libyul/optimiser/ASTWalker.h>
#include <libyul/Dialect.h>
namespace yul
{
struct Object;
class EVMToEWasmTranslator: public ASTModifier
{
public:
EVMToEWasmTranslator(Dialect const& _evmDialect): m_dialect(_evmDialect) {}
Object run(Object const& _object);
private:
void parsePolyfill();
Dialect const& m_dialect;
std::shared_ptr<Block> m_polyfill;
std::set<YulString> m_polyfillFunctions;
};
}

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@ -48,7 +48,8 @@ string EWasmCodeTransform::run(Dialect const& _dialect, yul::Block const& _ast)
statement.type() == typeid(yul::FunctionDefinition),
"Expected only function definitions at the highest level."
);
functions.emplace_back(transform.translateFunction(boost::get<yul::FunctionDefinition>(statement)));
if (statement.type() == typeid(yul::FunctionDefinition))
functions.emplace_back(transform.translateFunction(boost::get<yul::FunctionDefinition>(statement)));
}
return EWasmToText{}.run(transform.m_globalVariables, functions);
@ -65,6 +66,8 @@ wasm::Expression EWasmCodeTransform::generateMultiAssignment(
if (_variableNames.size() == 1)
return { std::move(assignment) };
allocateGlobals(_variableNames.size() - 1);
wasm::Block block;
block.statements.emplace_back(move(assignment));
for (size_t i = 1; i < _variableNames.size(); ++i)
@ -141,7 +144,7 @@ wasm::Expression EWasmCodeTransform::operator()(Identifier const& _identifier)
wasm::Expression EWasmCodeTransform::operator()(Literal const& _literal)
{
u256 value = valueOfLiteral(_literal);
yulAssert(value <= numeric_limits<uint64_t>::max(), "");
yulAssert(value <= numeric_limits<uint64_t>::max(), "Literal too large: " + value.str());
return wasm::Literal{uint64_t(value)};
}

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@ -52,6 +52,9 @@ WasmDialect::WasmDialect():
addFunction("drop", 1, 0);
addFunction("unreachable", 0, 0);
addFunction("datasize", 1, 4, true);
addFunction("dataoffset", 1, 4, true);
}
BuiltinFunction const* WasmDialect::builtin(YulString _name) const
@ -72,7 +75,7 @@ WasmDialect const& WasmDialect::instance()
return *dialect;
}
void WasmDialect::addFunction(string _name, size_t _params, size_t _returns)
void WasmDialect::addFunction(string _name, size_t _params, size_t _returns, bool _literalArguments)
{
YulString name{move(_name)};
BuiltinFunction& f = m_functions[name];
@ -85,5 +88,5 @@ void WasmDialect::addFunction(string _name, size_t _params, size_t _returns)
f.isMSize = false;
f.invalidatesStorage = true;
f.invalidatesMemory = true;
f.literalArguments = false;
f.literalArguments = _literalArguments;
}

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@ -53,7 +53,7 @@ struct WasmDialect: public Dialect
static WasmDialect const& instance();
private:
void addFunction(std::string _name, size_t _params, size_t _returns);
void addFunction(std::string _name, size_t _params, size_t _returns, bool _literalArguments = false);
std::map<YulString, BuiltinFunction> m_functions;
};

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@ -81,6 +81,5 @@ void NameDisplacer::checkAndReplace(YulString& _name) const
{
if (m_translations.count(_name))
_name = m_translations.at(_name);
yulAssert(!m_namesToFree.count(_name), "");
}

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@ -33,6 +33,9 @@ struct Dialect;
/**
* Optimiser component that renames identifiers to free up certain names.
*
* Only replaces names that have been defined inside the code. If the code uses
* names to be freed but does not define them, they remain unchanged.
*
* Prerequisites: Disambiguator
*/
class NameDisplacer: public ASTModifier

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@ -50,6 +50,7 @@
#include <libyul/AsmData.h>
#include <libyul/AsmPrinter.h>
#include <libyul/backends/wasm/WasmDialect.h>
#include <libyul/backends/evm/NoOutputAssembly.h>
#include <libdevcore/CommonData.h>
@ -215,6 +216,13 @@ void OptimiserSuite::run(
yulAssert(_meter, "");
ConstantOptimiser{*dialect, *_meter}(ast);
}
else if (dynamic_cast<WasmDialect const*>(&_dialect))
{
// If the first statement is an empty block, remove it.
// We should only have function definitions after that.
if (ast.statements.size() > 1 && boost::get<Block>(ast.statements.front()).statements.empty())
ast.statements.erase(ast.statements.begin());
}
VarNameCleaner{ast, _dialect, reservedIdentifiers}(ast);
yul::AsmAnalyzer::analyzeStrictAssertCorrect(_dialect, ast);