1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
|
/*
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/>.
*/
/**
* @date 2017
* Abstract assembly interface, subclasses of which are to be used with the generic
* bytecode generator.
*/
#pragma once
#include <libdevcore/Common.h>
#include <libdevcore/CommonData.h>
#include <functional>
#include <memory>
namespace langutil
{
struct SourceLocation;
}
namespace dev
{
namespace solidity
{
enum class Instruction: uint8_t;
}
}
namespace yul
{
struct Instruction;
struct Identifier;
///
/// Assembly class that abstracts both the libevmasm assembly and the new Yul assembly.
///
class AbstractAssembly
{
public:
using LabelID = size_t;
using SubID = size_t;
virtual ~AbstractAssembly() = default;
/// Set a new source location valid starting from the next instruction.
virtual void setSourceLocation(langutil::SourceLocation const& _location) = 0;
/// Retrieve the current height of the stack. This does not have to be zero
/// at the beginning.
virtual int stackHeight() const = 0;
/// Append an EVM instruction.
virtual void appendInstruction(dev::solidity::Instruction _instruction) = 0;
/// Append a constant.
virtual void appendConstant(dev::u256 const& _constant) = 0;
/// Append a label.
virtual void appendLabel(LabelID _labelId) = 0;
/// Append a label reference.
virtual void appendLabelReference(LabelID _labelId) = 0;
/// Generate a new unique label.
virtual LabelID newLabelId() = 0;
/// Returns a label identified by the given name. Creates it if it does not yet exist.
virtual LabelID namedLabel(std::string const& _name) = 0;
/// Append a reference to a to-be-linked symbol.
/// Currently, we assume that the value is always a 20 byte number.
virtual void appendLinkerSymbol(std::string const& _name) = 0;
/// Append a jump instruction.
/// @param _stackDiffAfter the stack adjustment after this instruction.
/// This is helpful to stack height analysis if there is no continuing control flow.
virtual void appendJump(int _stackDiffAfter) = 0;
/// Append a jump-to-immediate operation.
/// @param _stackDiffAfter the stack adjustment after this instruction.
virtual void appendJumpTo(LabelID _labelId, int _stackDiffAfter = 0) = 0;
/// Append a jump-to-if-immediate operation.
virtual void appendJumpToIf(LabelID _labelId) = 0;
/// Start a subroutine identified by @a _labelId that takes @a _arguments
/// stack slots as arguments.
virtual void appendBeginsub(LabelID _labelId, int _arguments) = 0;
/// Call a subroutine identified by @a _labelId, taking @a _arguments from the
/// stack upon call and putting @a _returns arguments onto the stack upon return.
virtual void appendJumpsub(LabelID _labelId, int _arguments, int _returns) = 0;
/// Return from a subroutine.
/// @param _stackDiffAfter the stack adjustment after this instruction.
virtual void appendReturnsub(int _returns, int _stackDiffAfter = 0) = 0;
/// Append the assembled size as a constant.
virtual void appendAssemblySize() = 0;
/// Creates a new sub-assembly, which can be referenced using dataSize and dataOffset.
virtual std::pair<std::shared_ptr<AbstractAssembly>, SubID> createSubAssembly() = 0;
/// Appends the offset of the given sub-assembly or data.
virtual void appendDataOffset(SubID _sub) = 0;
/// Appends the size of the given sub-assembly or data.
virtual void appendDataSize(SubID _sub) = 0;
/// Appends the given data to the assembly and returns its ID.
virtual SubID appendData(dev::bytes const& _data) = 0;
};
enum class IdentifierContext { LValue, RValue };
/// Object that is used to resolve references and generate code for access to identifiers external
/// to inline assembly (not used in standalone assembly mode).
struct ExternalIdentifierAccess
{
using Resolver = std::function<size_t(Identifier const&, IdentifierContext, bool /*_crossesFunctionBoundary*/)>;
/// Resolve an external reference given by the identifier in the given context.
/// @returns the size of the value (number of stack slots) or size_t(-1) if not found.
Resolver resolve;
using CodeGenerator = std::function<void(Identifier const&, IdentifierContext, yul::AbstractAssembly&)>;
/// Generate code for retrieving the value (rvalue context) or storing the value (lvalue context)
/// of an identifier. The code should be appended to the assembly. In rvalue context, the value is supposed
/// to be put onto the stack, in lvalue context, the value is assumed to be at the top of the stack.
CodeGenerator generateCode;
};
}
|
