solidity/libyul/backends/wasm/EVMToEWasmTranslator.cpp
2019-07-16 14:51:43 +02:00

696 lines
18 KiB
C++

/*
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 1
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), carry)
r2, carry := add_carry(x2, bit_negate(y2), carry)
r1, carry := add_carry(x1, bit_negate(y1), carry)
}
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))
}
// 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)
r4 := dl
let carry1, carry2
let t1, t2
r3, carry1 := add_carry(bl, cl, 0)
r3, carry2 := add_carry(r3, dh, 0)
t1, carry1 := add_carry(bh, ch, carry1)
r2, carry2 := add_carry(t1, al, carry2)
r1 := i64.add(i64.add(ah, carry1), carry2)
}
function mul(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
// TODO it would actually suffice to have mul_128x128_128 for the first two.
let b1, b2, b3, b4 := mul_128x128_256(x3, x4, y1, y2)
let c1, c2, c3, c4 := mul_128x128_256(x1, x2, y3, y4)
let d1, d2, d3, d4 := mul_128x128_256(x3, x4, y3, y4)
r4 := d4
r3 := d3
let t1, t2
t1, t2, r1, r2 := add(0, 0, b3, b4, 0, 0, c3, c4)
t1, t2, r1, r2 := add(0, 0, r1, r2, 0, 0, d1, d2)
}
function div(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
// TODO implement properly
r4 := i64.div_u(x4, y4)
}
function mod(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
// TODO implement properly
r4 := i64.rem_u(x4, y4)
}
function smod(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
// TODO implement properly
r4 := i64.rem_u(x4, y4)
}
function exp(x1, x2, x3, x4, y1, y2, y3, y4) -> r1, r2, r3, r4 {
// TODO implement properly
unreachable()
}
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
}
}
}
}
}
// returns 0 if a == b, -1 if a < b and 1 if a > b
function cmp(a, b) -> r {
switch i64.lt_u(a, b)
case 1 { r := 0xffffffffffffffff }
default {
switch i64.gt_u(a, b)
case 1 { r := 1 }
default { r := 0 }
}
}
function lt(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
switch cmp(x1, y1)
case 0 {
switch cmp(x2, y2)
case 0 {
switch cmp(x3, y3)
case 0 {
switch cmp(x4, y4)
case 0 { z4 := 0 }
case 1 { z4 := 0 }
default { z4 := 1 }
}
case 1 { z4 := 0 }
default { z4 := 1 }
}
case 1 { z4 := 0 }
default { z4 := 1 }
}
case 1 { z4 := 0 }
default { z4 := 1 }
}
function gt(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
z1, z2, z3, z4 := lt(y1, y2, y3, y4, x1, x2, x3, x4)
}
function slt(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
// TODO correct?
x1 := i64.add(x1, 0x8000000000000000)
y1 := i64.add(y1, 0x8000000000000000)
z1, z2, z3, z4 := lt(x1, x2, x3, x4, y1, y2, y3, y4)
}
function sgt(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
z1, z2, z3, z4 := slt(y1, y2, y3, y4, x1, x2, x3, x4)
}
function shl(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function shr(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function sar(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function addmod(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function mulmod(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function signextend(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function u256_to_i64(x1, x2, x3, x4) -> v {
if i64.ne(0, i64.or(i64.or(x1, x2), x3)) { invalid() }
v := x4
}
function u256_to_i32(x1, x2, x3, x4) -> v {
if i64.ne(0, i64.or(i64.or(x1, x2), x3)) { invalid() }
if i64.ne(0, i64.shr_u(x4, 32)) { invalid() }
v := x4
}
function u256_to_i32ptr(x1, x2, x3, x4) -> v {
v := u256_to_i32(x1, x2, x3, x4)
}
function keccak256(x1, x2, x3, x4, y1, y2, y3, y4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function address() -> z1, z2, z3, z4 {
let t1, t2, t3, t4 := save_temp_mem_32()
eth.getAddress(0)
z1, z2, z3, z4 := mload(0, 0, 0, 0)
restore_temp_mem_32(t1, t2, t3, t4)
}
function balance(x1, x2, x3, x4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function origin() -> z1, z2, z3, z4 {
let t1, t2, t3, t4 := save_temp_mem_32()
eth.getTxOrigin(0)
z1, z2, z3, z4 := mload(0, 0, 0, 0)
restore_temp_mem_32(t1, t2, t3, t4)
}
function caller() -> z1, z2, z3, z4 {
let t1, t2, t3, t4 := save_temp_mem_32()
eth.getCaller(0)
z1, z2, z3, z4 := mload(0, 0, 0, 0)
restore_temp_mem_32(t1, t2, t3, t4)
}
function callvalue() -> z1, z2, z3, z4 {
let t1, t2, t3, t4 := save_temp_mem_32()
eth.getCallValue(0)
z1, z2, z3, z4 := mload(0, 0, 0, 0)
restore_temp_mem_32(t1, t2, t3, t4)
}
function calldataload(x1, x2, x3, x4) -> z1, z2, z3, z4 {
let t1, t2, t3, t4 := save_temp_mem_32()
eth.callDataCopy(0, u256_to_i32(x1, x2, x3, x4), 32)
z1, z2, z3, z4 := mload(0, 0, 0, 0)
restore_temp_mem_32(t1, t2, t3, t4)
}
function calldatasize() -> z1, z2, z3, z4 {
z4 := eth.getCallDataSize()
}
function calldatacopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {
eth.callDataCopy(
u256_to_i32ptr(x1, x2, x3, x4),
u256_to_i32(y1, y2, y3, y4),
u256_to_i32(z1, z2, z3, z4)
)
}
// Needed?
function codesize() -> z1, z2, z3, z4 {
let t1, t2, t3, t4 := save_temp_mem_32()
eth.getCodeSize(0)
z1, z2, z3, z4 := mload(0, 0, 0, 0)
restore_temp_mem_32(t1, t2, t3, t4)
}
function codecopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {
eth.codeCopy(
u256_to_i32ptr(x1, x2, x3, x4),
u256_to_i32(y1, y2, y3, y4),
u256_to_i32(z1, z2, z3, z4)
)
}
function datacopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {
// TODO correct?
codecopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4)
}
function gasprice() -> z1, z2, z3, z4 {
let t1, t2, t3, t4 := save_temp_mem_32()
eth.getTxGasPrice(0)
z1, z2, z3, z4 := mload(0, 0, 0, 0)
restore_temp_mem_32(t1, t2, t3, t4)
}
function extcodesize(x1, x2, x3, x4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function extcodehash(x1, x2, x3, x4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function extcodecopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {
// TODO implement
unreachable()
}
function returndatasize() -> z1, z2, z3, z4 {
z4 := eth.getReturnDataSize()
}
function returndatacopy(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) {
eth.returnDataCopy(
u256_to_i32ptr(x1, x2, x3, x4),
u256_to_i32(y1, y2, y3, y4),
u256_to_i32(z1, z2, z3, z4)
)
}
function blockhash(x1, x2, x3, x4) -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function coinbase() -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function timestamp() -> z1, z2, z3, z4 {
z4 := eth.getBlockTimestamp()
}
function number() -> z1, z2, z3, z4 {
z4 := eth.getBlockNumber()
}
function difficulty() -> z1, z2, z3, z4 {
let t1, t2, t3, t4 := save_temp_mem_32()
eth.getBlockDifficulty(0)
z1, z2, z3, z4 := mload(0, 0, 0, 0)
restore_temp_mem_32(t1, t2, t3, t4)
}
function gaslimit() -> z1, z2, z3, z4 {
z4 := eth.getBlockGasLimit()
}
function pop(x1, x2, x3, x4) {
}
function endian_swap_16(x) -> y {
let hi := i64.and(i64.shl(x, 8), 0xff00)
let lo := i64.and(i64.shr_u(x, 8), 0xff)
y := i64.or(hi, lo)
}
function endian_swap_32(x) -> y {
let hi := i64.shl(endian_swap_16(x), 16)
let lo := endian_swap_16(i64.shr_u(x, 16))
y := i64.or(hi, lo)
}
function endian_swap(x) -> y {
let hi := i64.shl(endian_swap_32(x), 32)
let lo := endian_swap_32(i64.shr_u(x, 32))
y := i64.or(hi, lo)
}
function save_temp_mem_32() -> t1, t2, t3, t4 {
t1 := i64.load(0)
t2 := i64.load(8)
t3 := i64.load(16)
t4 := i64.load(24)
}
function restore_temp_mem_32(t1, t2, t3, t4) {
i64.store(0, t1)
i64.store(8, t2)
i64.store(16, t3)
i64.store(24, t4)
}
function save_temp_mem_64() -> t1, t2, t3, t4, t5, t6, t7, t8 {
t1 := i64.load(0)
t2 := i64.load(8)
t3 := i64.load(16)
t4 := i64.load(24)
t5 := i64.load(32)
t6 := i64.load(40)
t7 := i64.load(48)
t8 := i64.load(54)
}
function restore_temp_mem_64(t1, t2, t3, t4, t5, t6, t7, t8) {
i64.store(0, t1)
i64.store(8, t2)
i64.store(16, t3)
i64.store(24, t4)
i64.store(32, t5)
i64.store(40, t6)
i64.store(48, t7)
i64.store(54, t8)
}
function mload(x1, x2, x3, x4) -> z1, z2, z3, z4 {
let pos := u256_to_i32ptr(x1, x2, x3, x4)
z1 := endian_swap(i64.load(pos))
z2 := endian_swap(i64.load(i64.add(pos, 8)))
z3 := endian_swap(i64.load(i64.add(pos, 16)))
z4 := endian_swap(i64.load(i64.add(pos, 24)))
}
function mstore(x1, x2, x3, x4, y1, y2, y3, y4) {
let pos := u256_to_i32ptr(x1, x2, x3, x4)
i64.store(pos, endian_swap(x1))
i64.store(i64.add(pos, 8), endian_swap(x2))
i64.store(i64.add(pos, 16), endian_swap(x3))
i64.store(i64.add(pos, 24), endian_swap(x4))
}
function mstore8(x1, x2, x3, x4, y1, y2, y3, y4) {
// TODO implement
unreachable()
}
// Needed?
function msize() -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function sload(x1, x2, x3, x4) -> z1, z2, z3, z4 {
let t1, t2, t3, t4, t5, t6, t7, t8 := save_temp_mem_64()
mstore(0, 0, 0, 0, x1, x2, x3, x4)
eth.storageLoad(0, 16)
z1, z2, z3, z4 := mload(0, 0, 0, 16)
restore_temp_mem_64(t1, t2, t3, t4, t5, t6, t7, t8)
}
function sstore(x1, x2, x3, x4, y1, y2, y3, y4) {
let t1, t2, t3, t4, t5, t6, t7, t8 := save_temp_mem_64()
mstore(0, 0, 0, 0, x1, x2, x3, x4)
mstore(0, 0, 0, 32, y1, y2, y3, y4)
eth.storageStore(0, 32)
restore_temp_mem_64(t1, t2, t3, t4, t5, t6, t7, t8)
}
// Needed?
function pc() -> z1, z2, z3, z4 {
// TODO implement
unreachable()
}
function gas() -> z1, z2, z3, z4 {
z4 := eth.getGasLeft()
}
function log0(p1, p2, p3, p4, s1, s2, s3, s4) {
// TODO implement
unreachable()
}
function log1(
p1, p2, p3, p4, s1, s2, s3, s4,
t11, t12, t13, t14
) {
// TODO implement
unreachable()
}
function log2(
p1, p2, p3, p4, s1, s2, s3, s4,
t11, t12, t13, t14,
t21, t22, t23, t24
) {
// TODO implement
unreachable()
}
function log3(
p1, p2, p3, p4, s1, s2, s3, s4,
t11, t12, t13, t14,
t21, t22, t23, t24,
t31, t32, t33, t34
) {
// TODO implement
unreachable()
}
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,
) {
// TODO implement
unreachable()
}
function create(x1, x2, x3, x4, y1, y2, y3, y4, z1, z2, z3, z4) -> a1, a2, a3, a4 {
// TODO implement
unreachable()
}
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 {
// TODO implement
unreachable()
}
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 {
// TODO implement
unreachable()
}
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 {
// TODO implement
unreachable()
}
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 {
// TODO implement
unreachable()
}
function create2(
a1, a2, a3, a4,
b1, b2, b3, b4,
c1, c2, c3, c4,
d1, d2, d3, d4
) -> x1, x2, x3, x4 {
// TODO implement
unreachable()
}
function selfdestruct(a1, a2, a3, a4) {
mstore(0, 0, 0, 0, a1, a2, a3, a4)
// In EVM, addresses are padded to 32 bytes, so discard the first 12.
eth.selfDestruct(12)
}
function return(x1, x2, x3, x4, y1, y2, y3, y4) {
eth.finish(
u256_to_i32ptr(x1, x2, x3, x4),
u256_to_i32(y1, y2, y3, y4)
)
}
function revert(x1, x2, x3, x4, y1, y2, y3, y4) {
eth.revert(
u256_to_i32ptr(x1, x2, x3, x4),
u256_to_i32(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(), {}, _object.dataNames());
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);
}