solidity/libyul/backends/wasm/WasmDialect.cpp
2021-08-12 16:37:21 +02:00

284 lines
9.5 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/>.
*/
// SPDX-License-Identifier: GPL-3.0
/**
* Dialects for Wasm.
*/
#include <libyul/backends/wasm/WasmDialect.h>
#include <libyul/AST.h>
#include <libyul/Exceptions.h>
using namespace std;
using namespace solidity::yul;
WasmDialect::WasmDialect()
{
YulString i64 = "i64"_yulstring;
YulString i32 = "i32"_yulstring;
defaultType = i64;
boolType = i32;
types = {i64, i32};
for (auto t: types)
for (auto const& name: {
"add",
"sub",
"mul",
// TODO: div_s
"div_u",
// TODO: rem_s
"rem_u",
"and",
"or",
"xor",
"shl",
// TODO: shr_s
"shr_u",
// TODO: rotl
// TODO: rotr
})
addFunction(t.str() + "." + name, {t, t}, {t});
for (auto t: types)
for (auto const& name: {
"eq",
"ne",
// TODO: lt_s
"lt_u",
// TODO: gt_s
"gt_u",
// TODO: le_s
"le_u",
// TODO: ge_s
"ge_u"
})
addFunction(t.str() + "." + name, {t, t}, {i32});
addFunction("i32.eqz", {i32}, {i32});
addFunction("i64.eqz", {i64}, {i32});
for (auto t: types)
for (auto const& name: {
"clz",
"ctz",
"popcnt",
})
addFunction(t.str() + "." + name, {t}, {t});
addFunction("i32.wrap_i64", {i64}, {i32});
addFunction("i64.extend_i32_u", {i32}, {i64});
addFunction("i32.store", {i32, i32}, {}, false);
m_functions["i32.store"_yulstring].sideEffects.storage = SideEffects::None;
m_functions["i32.store"_yulstring].sideEffects.otherState = SideEffects::None;
addFunction("i64.store", {i32, i64}, {}, false);
// TODO: add i32.store16, i64.store8, i64.store16, i64.store32
m_functions["i64.store"_yulstring].sideEffects.storage = SideEffects::None;
m_functions["i64.store"_yulstring].sideEffects.otherState = SideEffects::None;
addFunction("i32.store8", {i32, i32}, {}, false);
m_functions["i32.store8"_yulstring].sideEffects.storage = SideEffects::None;
m_functions["i32.store8"_yulstring].sideEffects.otherState = SideEffects::None;
addFunction("i64.store8", {i32, i64}, {}, false);
m_functions["i64.store8"_yulstring].sideEffects.storage = SideEffects::None;
m_functions["i64.store8"_yulstring].sideEffects.otherState = SideEffects::None;
addFunction("i32.load", {i32}, {i32}, false);
m_functions["i32.load"_yulstring].sideEffects.canBeRemoved = true;
m_functions["i32.load"_yulstring].sideEffects.canBeRemovedIfNoMSize = true;
m_functions["i32.load"_yulstring].sideEffects.storage = SideEffects::None;
m_functions["i32.load"_yulstring].sideEffects.memory = SideEffects::Read;
m_functions["i32.load"_yulstring].sideEffects.otherState = SideEffects::None;
addFunction("i64.load", {i32}, {i64}, false);
// TODO: add i32.load8, i32.load16, i64.load8, i64.load16, i64.load32
m_functions["i64.load"_yulstring].sideEffects.canBeRemoved = true;
m_functions["i64.load"_yulstring].sideEffects.canBeRemovedIfNoMSize = true;
m_functions["i64.load"_yulstring].sideEffects.storage = SideEffects::None;
m_functions["i64.load"_yulstring].sideEffects.memory = SideEffects::Read;
m_functions["i64.load"_yulstring].sideEffects.otherState = SideEffects::None;
// Drop is actually overloaded for all types, but Yul does not support that.
// Because of that, we introduce "i32.drop" and "i64.drop".
addFunction("i32.drop", {i32}, {});
addFunction("i64.drop", {i64}, {});
// Select is also overloaded.
addFunction("i32.select", {i32, i32, i32}, {i32});
addFunction("i64.select", {i64, i64, i32}, {i64});
addFunction("nop", {}, {});
addFunction("unreachable", {}, {}, false);
m_functions["unreachable"_yulstring].sideEffects.storage = SideEffects::None;
m_functions["unreachable"_yulstring].sideEffects.memory = SideEffects::None;
m_functions["unreachable"_yulstring].sideEffects.otherState = SideEffects::None;
m_functions["unreachable"_yulstring].controlFlowSideEffects.terminates = true;
m_functions["unreachable"_yulstring].controlFlowSideEffects.reverts = true;
addFunction("datasize", {i64}, {i64}, true, {LiteralKind::String});
addFunction("dataoffset", {i64}, {i64}, true, {LiteralKind::String});
addExternals();
}
BuiltinFunction const* WasmDialect::builtin(YulString _name) const
{
auto it = m_functions.find(_name);
if (it != m_functions.end())
return &it->second;
else
return nullptr;
}
BuiltinFunction const* WasmDialect::discardFunction(YulString _type) const
{
if (_type == "i32"_yulstring)
return builtin("i32.drop"_yulstring);
yulAssert(_type == "i64"_yulstring, "");
return builtin("i64.drop"_yulstring);
}
BuiltinFunction const* WasmDialect::equalityFunction(YulString _type) const
{
if (_type == "i32"_yulstring)
return builtin("i32.eq"_yulstring);
yulAssert(_type == "i64"_yulstring, "");
return builtin("i64.eq"_yulstring);
}
WasmDialect const& WasmDialect::instance()
{
static std::unique_ptr<WasmDialect> dialect;
static YulStringRepository::ResetCallback callback{[&] { dialect.reset(); }};
if (!dialect)
dialect = make_unique<WasmDialect>();
return *dialect;
}
void WasmDialect::addExternals()
{
// These are not YulStrings because that would be too complicated with regards
// to the YulStringRepository reset.
static string const i64{"i64"};
static string const i32{"i32"};
static string const i32ptr{"i32"}; // Uses "i32" on purpose.
struct External
{
string module;
string name;
vector<string> parameters;
vector<string> returns;
ControlFlowSideEffects controlFlowSideEffects = ControlFlowSideEffects{};
};
static vector<External> externals{
{"eth", "getAddress", {i32ptr}, {}},
{"eth", "getExternalBalance", {i32ptr, i32ptr}, {}},
{"eth", "getBlockBaseFee", {i32ptr}, {}},
{"eth", "getBlockHash", {i64, i32ptr}, {i32}},
{"eth", "call", {i64, i32ptr, i32ptr, i32ptr, i32}, {i32}},
{"eth", "callDataCopy", {i32ptr, i32, i32}, {}},
{"eth", "getCallDataSize", {}, {i32}},
{"eth", "callCode", {i64, i32ptr, i32ptr, i32ptr, i32}, {i32}},
{"eth", "callDelegate", {i64, i32ptr, i32ptr, i32}, {i32}},
{"eth", "callStatic", {i64, i32ptr, i32ptr, i32}, {i32}},
{"eth", "storageStore", {i32ptr, i32ptr}, {}},
{"eth", "storageLoad", {i32ptr, i32ptr}, {}},
{"eth", "getCaller", {i32ptr}, {}},
{"eth", "getCallValue", {i32ptr}, {}},
{"eth", "codeCopy", {i32ptr, i32, i32}, {}},
{"eth", "getCodeSize", {}, {i32}},
{"eth", "getBlockCoinbase", {i32ptr}, {}},
{"eth", "create", {i32ptr, i32ptr, i32, i32ptr}, {i32}},
{"eth", "getBlockDifficulty", {i32ptr}, {}},
{"eth", "externalCodeCopy", {i32ptr, i32ptr, i32, i32}, {}},
{"eth", "getExternalCodeSize", {i32ptr}, {i32}},
{"eth", "getGasLeft", {}, {i64}},
{"eth", "getBlockGasLimit", {}, {i64}},
{"eth", "getTxGasPrice", {i32ptr}, {}},
{"eth", "log", {i32ptr, i32, i32, i32ptr, i32ptr, i32ptr, i32ptr}, {}},
{"eth", "getBlockNumber", {}, {i64}},
{"eth", "getTxOrigin", {i32ptr}, {}},
{"eth", "finish", {i32ptr, i32}, {}, ControlFlowSideEffects{true, false}},
{"eth", "revert", {i32ptr, i32}, {}, ControlFlowSideEffects{true, true}},
{"eth", "getReturnDataSize", {}, {i32}},
{"eth", "returnDataCopy", {i32ptr, i32, i32}, {}},
{"eth", "selfDestruct", {i32ptr}, {}, ControlFlowSideEffects{true, false}},
{"eth", "getBlockTimestamp", {}, {i64}},
{"debug", "print32", {i32}, {}},
{"debug", "print64", {i64}, {}},
{"debug", "printMem", {i32, i32}, {}},
{"debug", "printMemHex", {i32, i32}, {}},
{"debug", "printStorage", {i32}, {}},
{"debug", "printStorageHex", {i32}, {}},
};
for (External const& ext: externals)
{
YulString name{ext.module + "." + ext.name};
BuiltinFunction& f = m_functions[name];
f.name = name;
for (string const& p: ext.parameters)
f.parameters.emplace_back(YulString(p));
for (string const& p: ext.returns)
f.returns.emplace_back(YulString(p));
// TODO some of them are side effect free.
f.sideEffects = SideEffects::worst();
f.sideEffects.cannotLoop = true;
f.sideEffects.movableApartFromEffects = !ext.controlFlowSideEffects.terminates;
f.controlFlowSideEffects = ext.controlFlowSideEffects;
f.isMSize = false;
f.literalArguments.clear();
static set<string> const writesToStorage{
"storageStore",
"call",
"callcode",
"callDelegate",
"create"
};
static set<string> const readsStorage{"storageLoad", "callStatic"};
if (readsStorage.count(ext.name))
f.sideEffects.storage = SideEffects::Read;
else if (!writesToStorage.count(ext.name))
f.sideEffects.storage = SideEffects::None;
}
}
void WasmDialect::addFunction(
string _name,
vector<YulString> _params,
vector<YulString> _returns,
bool _movable,
vector<optional<LiteralKind>> _literalArguments
)
{
YulString name{move(_name)};
BuiltinFunction& f = m_functions[name];
f.name = name;
f.parameters = std::move(_params);
yulAssert(_returns.size() <= 1, "The Wasm 1.0 specification only allows up to 1 return value.");
f.returns = std::move(_returns);
f.sideEffects = _movable ? SideEffects{} : SideEffects::worst();
f.sideEffects.cannotLoop = true;
// TODO This should be improved when LoopInvariantCodeMotion gets specialized for WASM
f.sideEffects.movableApartFromEffects = _movable;
f.isMSize = false;
f.literalArguments = std::move(_literalArguments);
}