pycparser的语法树节点可由_c_ast.cfg配置并生成，默认情况下其提供了以下节点(Node)：
在该文件的原文中是按照如下规则标记属性值的：
# Each entry is a Node sub-class name, listing the attributes
# and child nodes of the class:
# <name>* - a child node
# <name>** - a sequence of child nodes
# <name> - an attribute
即：
<name>* 的，是一个子节点
<name>** 的，是子节点序列
<name> 的，是一个属性值
数组声明，其拥有以下属性值：
当其为一位数组时，该
type
是一个Node，TODO
dim
是一个Node，是维度，TODO
Demo
int length = 10;
int arr[5][length] = { 0 };
FileAST(ext=[Decl(name='length',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='length',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=Constant(type='int',
value='10'
),
bitsize=None
),
Decl(name='arr',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=ArrayDecl(type=ArrayDecl(type=TypeDecl(declname='arr',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
dim=ID(name='length'
),
dim_quals=[
]
),
dim=Constant(type='int',
value='5'
),
dim_quals=[
]
),
init=InitList(exprs=[Constant(type='int',
value='0'
)
]
),
bitsize=None
)
]
)
数组值引用，其拥有以下属性值：
name
subscript
Demo
int array[10] = { 0 };
int val = array[5];
FileAST(ext=[Decl(name='array',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=ArrayDecl(type=TypeDecl(declname='array',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
dim=Constant(type='int',
value='10'
),
dim_quals=[
]
),
init=InitList(exprs=[Constant(type='int',
value='0'
)
]
),
bitsize=None
),
Decl(name='val',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='val',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=ArrayRef(name=ID(name='array'
),
subscript=Constant(type='int',
value='5'
)
),
bitsize=None
)
]
)
赋值操作符，有以下几种：
=*=/=%=+=-=<<=>>=&=|=^=其拥有以下属性值：
op
类型为字符串，是上述操作符的字符串形式
lvalue
左值
rvalue
右值
Demo
void func()
{
int val = 0;
val += 1;
}
FileAST(ext=[FuncDef(decl=Decl(name='func',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=FuncDecl(args=None,
type=TypeDecl(declname='func',
quals=[
],
align=None,
type=IdentifierType(names=['void'
]
)
)
),
init=None,
bitsize=None
),
param_decls=None,
body=Compound(block_items=[Decl(name='val',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='val',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=Constant(type='int',
value='0'
),
bitsize=None
),
Assignment(op='+=',
lvalue=ID(name='val'
),
rvalue=Constant(type='int',
value='1'
)
)
]
)
)
]
)
字节对齐，即C11中的 _Alignas ，C标准学习笔记 > 6 7 5 字节对齐说明符，其拥有以下属性：
alignment
是一个Node，含义为对齐参数
Demo
int _Alignas(8) a;
int b;
FileAST(ext=[Decl(name='a',
quals=[
],
align=[Alignas(alignment=Constant(type='int',
value='8'
)
)
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
),
Decl(name='b',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='b',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
)
]
)
二进制运算符，有以下几种：
+-*/%|&~^<<>>||&&!<><=>===!=Dataview (inline field '='): Error:
-- PARSING FAILED --------------------------------------------------
> 1 | =
| ^
Expected one of the following:
'(', 'null', boolean, date, duration, file link, list ('[1, 2, 3]'), negated field, number, object ('{ a: 1, b: 2 }'), string, variable
其拥有如下属性：
op
类型为字符串，是上述操作符的字符串形式
TODO.
Demo
int a = 1;
int b = a == 1;
FileAST(ext=[Decl(name='a',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=Constant(type='int',
value='1'
),
bitsize=None
),
Decl(name='b',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='b',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=BinaryOp(op='==',
left=ID(name='a'
),
right=Constant(type='int',
value='1'
)
),
bitsize=None
)
]
)
Demo
void func()
{
while(1)
{
break;
}
}
FileAST(ext=[FuncDef(decl=Decl(name='func',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=FuncDecl(args=None,
type=TypeDecl(declname='func',
quals=[
],
align=None,
type=IdentifierType(names=['void'
]
)
)
),
init=None,
bitsize=None
),
param_decls=None,
body=Compound(block_items=[While(cond=Constant(type='int',
value='1'
),
stmt=Compound(block_items=[Break()
]
)
)
]
)
)
]
)
Demo
int *p = (int[]) { 1, 2, 3 };
FileAST(ext=[Decl(name='p',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=PtrDecl(quals=[
],
type=TypeDecl(declname='p',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
)
),
init=CompoundLiteral(type=Typename(name=None,
quals=[
],
align=None,
type=ArrayDecl(type=TypeDecl(declname=None,
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
dim=None,
dim_quals=[
]
)
),
init=InitList(exprs=[Constant(type='int',
value='1'
),
Constant(type='int',
value='2'
),
Constant(type='int',
value='3'
)
]
)
),
bitsize=None
)
]
)
即常量，其属性有：
type
value
Demo
const int a = 1;
int b = 0;
FileAST(ext=[Decl(name='a',
quals=['const'
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=['const'
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=Constant(type='int',
value='1'
),
bitsize=None
),
Decl(name='b',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='b',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=Constant(type='int',
value='1'
),
bitsize=None
)
]
)
所有声明语句均为Decl，
其属性有：
namename 仅为声明对象的名字，类型为字符串
qualsquals 为对象的限定符，包含：
constvolatilerestrictalign即C语言中的字节对齐说明符：C标准学习笔记 > 6 7 5 字节对齐说明符
Demo
_Alignas(char) int a;
FileAST(ext=[Decl(name='a',
quals=[
],
align=[Alignas(alignment=Typename(name=None,
quals=[
],
align=None,
type=TypeDecl(declname=None,
quals=[
],
align=None,
type=IdentifierType(names=['char'
]
)
)
)
)
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
)
]
)
_Alignas(2) int a;
FileAST(ext=[Decl(name='a',
quals=[
],
align=[Alignas(alignment=Constant(type='int',
value='2'
)
)
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
)
]
)
storgestorage` 为C语言的储存类型说明符，详见：C标准学习笔记 > 6.7.1 储存类型说明符
typedefexternstatic_Thread_localautoregisterfuncspec 为C语言的函数说明符，详见：C标准学习笔记 > 6.7.4 函数说明符
最小示例：
int a;
FileAST(ext=[Decl(name='a',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
)
]
)
变量示例：
int a, b;
int mprint(char* fmt, ...);
;
Demo
enum enum_type { a, b, c };
enum enum_type obj;
则其中的 obj 即为 Enum ， a 则为 Enumerator ， { a, b, c } 则为 EnumeratorList
FileAST(ext=[Decl(name=None,
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=Enum(name='enum_type',
values=EnumeratorList(enumerators=[Enumerator(name='a',
value=None
),
Enumerator(name='b',
value=None
),
Enumerator(name='c',
value=None
)
]
)
),
init=None,
bitsize=None
),
Decl(name='obj',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='obj',
quals=[
],
align=None,
type=Enum(name='enum_type',
values=None
)
),
init=None,
bitsize=None
)
]
)
Demo
enum enum_type { a, b, c };
enum enum_type obj;
则其中的 obj 即为 Enum ， a 则为 Enumerator ， { a, b, c } 则为 EnumeratorList
FileAST(ext=[Decl(name=None,
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=Enum(name='enum_type',
values=EnumeratorList(enumerators=[Enumerator(name='a',
value=None
),
Enumerator(name='b',
value=None
),
Enumerator(name='c',
value=None
)
]
)
),
init=None,
bitsize=None
),
Decl(name='obj',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='obj',
quals=[
],
align=None,
type=Enum(name='enum_type',
values=None
)
),
init=None,
bitsize=None
)
]
)
Demo
enum enum_type { a, b, c };
enum enum_type obj;
则其中的 obj 即为 Enum ， a 则为 Enumerator ， { a, b, c } 则为 EnumeratorList
FileAST(ext=[Decl(name=None,
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=Enum(name='enum_type',
values=EnumeratorList(enumerators=[Enumerator(name='a',
value=None
),
Enumerator(name='b',
value=None
),
Enumerator(name='c',
value=None
)
]
)
),
init=None,
bitsize=None
),
Decl(name='obj',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='obj',
quals=[
],
align=None,
type=Enum(name='enum_type',
values=None
)
),
init=None,
bitsize=None
)
]
)
Demo
int a, b, c = (a = 1, b = 2);
expression list以逗号为分隔，其表达式值为最后一个语句的值，此时的 a 、 b 、 c 分别为 1 、 2 、 2 。
FileAST(ext=[Decl(name='a',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
),
Decl(name='b',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='b',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
),
Decl(name='c',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='c',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=ExprList(exprs=[Assignment(op='=',
lvalue=ID(name='a'
),
rvalue=Constant(type='int',
value='1'
)
),
Assignment(op='=',
lvalue=ID(name='b'
),
rvalue=Constant(type='int',
value='2'
)
)
]
),
bitsize=None
)
]
)
FileAST作为AST的顶部，表示经过预处理后的单个C文件，也是C语言标准中的术语 翻译单元 ，其包含外部声明列表("external-declaration"s)，即声明(Decl)、Typedef或函数定义(FuncDef)。
其拥有属性值：
ext
是子节点序列，元素即为上述的"external-declaration"s
argstypeint a;
FileAST(ext=[Decl(name='a',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
)
]
)
Demo
int a[3] = { 1, 2, 3 };
FileAST(ext=[Decl(name='a',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=ArrayDecl(type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
dim=Constant(type='int',
value='3'
),
dim_quals=[
]
),
init=InitList(exprs=[Constant(type='int',
value='1'
),
Constant(type='int',
value='2'
),
Constant(type='int',
value='3'
)
]
),
bitsize=None
)
]
)
Demo
struct { int a; int b; } obj = { .a = 1, .b = 2 };
FileAST(ext=[Decl(name='obj',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='obj',
quals=[
],
align=None,
type=Struct(name=None,
decls=[Decl(name='a',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
),
Decl(name='b',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='b',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
),
init=None,
bitsize=None
)
]
)
),
init=InitList(exprs=[NamedInitializer(name=[ID(name='a'
)
],
expr=Constant(type='int',
value='1'
)
),
NamedInitializer(name=[ID(name='b'
)
],
expr=Constant(type='int',
value='2'
)
)
]
),
bitsize=None
)
]
)
Demo
int *a;
FileAST(ext=[Decl(name='a',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=PtrDecl(quals=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['int'
]
)
)
),
init=None,
bitsize=None
)
]
)
Demo
void func(int);
Demo
char a = ! 0xf0;
FileAST(ext=[Decl(name='a',
quals=[
],
align=[
],
storage=[
],
funcspec=[
],
type=TypeDecl(declname='a',
quals=[
],
align=None,
type=IdentifierType(names=['char'
]
)
),
init=UnaryOp(op='!',
expr=Constant(type='int',
value='0xf0'
)
),
bitsize=None
)
]
)