1 /*
2 	This file is part of solidity.
3 
4 	solidity is free software: you can redistribute it and/or modify
5 	it under the terms of the GNU General Public License as published by
6 	the Free Software Foundation, either version 3 of the License, or
7 	(at your option) any later version.
8 
9 	solidity is distributed in the hope that it will be useful,
10 	but WITHOUT ANY WARRANTY; without even the implied warranty of
11 	MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
12 	GNU General Public License for more details.
13 
14 	You should have received a copy of the GNU General Public License
15 	along with solidity.  If not, see <http://www.gnu.org/licenses/>.
16 */
17 // SPDX-License-Identifier: GPL-3.0
18 /**
19  * Common code generator for translating Yul / inline assembly to Wasm.
20  */
21 
22 #pragma once
23 
24 #include <libyul/backends/wasm/WasmAST.h>
25 #include <libyul/ASTForward.h>
26 #include <libyul/Dialect.h>
27 #include <libyul/optimiser/NameDispenser.h>
28 #include <libyul/optimiser/TypeInfo.h>
29 
30 #include <libsolutil/Common.h>
31 #include <libsolutil/Numeric.h>
32 
33 #include <stack>
34 #include <map>
35 
36 namespace solidity::yul
37 {
38 struct AsmAnalysisInfo;
39 
40 class WasmCodeTransform
41 {
42 public:
43 	static wasm::Module run(Dialect const& _dialect, yul::Block const& _ast);
44 
45 public:
46 	wasm::Expression operator()(yul::Literal const& _literal);
47 	wasm::Expression operator()(yul::Identifier const& _identifier);
48 	wasm::Expression operator()(yul::FunctionCall const&);
49 	wasm::Expression operator()(yul::ExpressionStatement const& _statement);
50 	wasm::Expression operator()(yul::Assignment const& _assignment);
51 	wasm::Expression operator()(yul::VariableDeclaration const& _varDecl);
52 	wasm::Expression operator()(yul::If const& _if);
53 	wasm::Expression operator()(yul::Switch const& _switch);
54 	wasm::Expression operator()(yul::FunctionDefinition const&);
55 	wasm::Expression operator()(yul::ForLoop const&);
56 	wasm::Expression operator()(yul::Break const&);
57 	wasm::Expression operator()(yul::Continue const&);
58 	wasm::Expression operator()(yul::Leave const&);
59 	wasm::Expression operator()(yul::Block const& _block);
60 
61 private:
WasmCodeTransform(Dialect const & _dialect,Block const & _ast,TypeInfo & _typeInfo)62 	WasmCodeTransform(
63 		Dialect const& _dialect,
64 		Block const& _ast,
65 		TypeInfo& _typeInfo
66 	):
67 		m_dialect(_dialect),
68 		m_nameDispenser(_dialect, _ast),
69 		m_typeInfo(_typeInfo)
70 	{}
71 
72 	std::unique_ptr<wasm::Expression> visit(yul::Expression const& _expression);
73 	wasm::Expression visitReturnByValue(yul::Expression const& _expression);
74 	std::vector<wasm::Expression> visit(std::vector<yul::Expression> const& _expressions);
75 	wasm::Expression visit(yul::Statement const& _statement);
76 	std::vector<wasm::Expression> visit(std::vector<yul::Statement> const& _statements);
77 
78 	/// Returns an assignment or a block containing multiple assignments.
79 	/// @param _variableNames the names of the variables to assign to
80 	/// @param _firstValue the value to be assigned to the first variable. If there
81 	///        is more than one variable, the values are taken from m_globalVariables.
82 	wasm::Expression generateMultiAssignment(
83 		std::vector<std::string> _variableNames,
84 		std::unique_ptr<wasm::Expression> _firstValue
85 	);
86 
87 	wasm::FunctionDefinition translateFunction(yul::FunctionDefinition const& _funDef);
88 
89 	/// Imports an external function into the current module.
90 	/// @param _builtin _builtin the builtin that will be imported into the current module.
91 	/// @param _module _module the module name under which the external function can be found.
92 	/// @param _externalName the name of the external function within the module _module.
93 	/// @param _internalName the name of the internal function under that the external function is accessible.
94 	void importBuiltinFunction(BuiltinFunction const* _builtin, std::string const& _module, std::string const& _externalName, std::string const& _internalName);
95 
96 	std::string newLabel();
97 	/// Selects a subset of global variables matching specified sequence of variable types.
98 	/// Defines more global variables of a given type if there's not enough.
99 	std::vector<size_t> allocateGlobals(std::vector<wasm::Type> const& _typesForGlobals);
100 
101 	static wasm::Type translatedType(yul::Type _yulType);
102 	static wasm::Literal makeLiteral(wasm::Type _type, u256 _value);
103 
104 	Dialect const& m_dialect;
105 	NameDispenser m_nameDispenser;
106 
107 	std::vector<wasm::VariableDeclaration> m_localVariables;
108 	std::vector<wasm::GlobalVariableDeclaration> m_globalVariables;
109 	std::map<YulString, wasm::FunctionImport> m_functionsToImport;
110 	std::string m_functionBodyLabel;
111 	std::stack<std::pair<std::string, std::string>> m_breakContinueLabelNames;
112 	TypeInfo& m_typeInfo;
113 };
114 
115 }
116