1+ //! Intermediate representation for attributes.
2+ use std:: str;
3+
4+ use clang:: Cursor ;
5+ use clang_sys:: { CXCursor_UnexposedAttr , CXChildVisit_Continue } ;
6+ use cexpr:: token:: { Token , Kind } ;
7+
8+ use super :: context:: BindgenContext ;
9+
10+ /// The special attribute
11+ #[ derive( Clone , Debug ) ]
12+ pub enum Attribute {
13+ /// This attribute results in a warning if the type is used anywhere in the source file.
14+ Deprecated ( Option < String > ) ,
15+ /// This attribute means that variables of that type are meant to appear possibly unused.
16+ Unused ,
17+ /// This attribute attached to a function, means that code must be emitted for the function
18+ /// even if it appears that the function is not referenced.
19+ Used ,
20+ /// This attribute on functions is used to inform the compiler that the function is unlikely to be executed.
21+ Cold ,
22+ /// Many functions do not examine any values except their arguments,
23+ /// and have no effects except the return value.
24+ Const ,
25+ /// This attribute causes the function to be called automatically before execution enters main ().
26+ Constructor ( Option < isize > ) ,
27+ /// This attribute causes the function to be called automatically after main () completes or exit () is called.
28+ Destructor ( Option < isize > ) ,
29+ /// This attribute specifies a minimum alignment (in bytes)
30+ Aligned ( Vec < Token > ) ,
31+ /// An attribute whose specific kind is not exposed via this interface.
32+ Unexposed ( String , Vec < Token > )
33+ }
34+
35+ impl Attribute {
36+ /// Construct a new `Attribute`.
37+ pub fn new ( tokens : Vec < Token > ) -> Self {
38+ // https://gcc.gnu.org/onlinedocs/gcc/Attribute-Syntax.html#Attribute-Syntax
39+ assert ! ( !tokens. is_empty( ) ) ;
40+
41+ let ( token, args) = tokens. split_first ( ) . unwrap ( ) ;
42+
43+ assert_eq ! ( token. kind, Kind :: Identifier ) ;
44+
45+ let name = unsafe { str:: from_utf8_unchecked ( & token. raw ) } ;
46+
47+ debug ! ( "__attribute__(({}({:?})))" , name, args) ;
48+
49+ match name {
50+ "deprecated" => {
51+ let text = if args. len ( ) == 3 &&
52+ args[ 0 ] . kind == Kind :: Punctuation && args[ 0 ] . raw . as_ref ( ) == b"(" &&
53+ args[ 1 ] . kind == Kind :: Literal &&
54+ args[ 2 ] . kind == Kind :: Punctuation && args[ 2 ] . raw . as_ref ( ) == b")" {
55+ str:: from_utf8 ( args[ 1 ] . raw . as_ref ( ) ) . ok ( ) . map ( String :: from)
56+ } else {
57+ None
58+ } ;
59+
60+ Attribute :: Deprecated ( text)
61+ }
62+ "unused" => Attribute :: Unused ,
63+ "used" => Attribute :: Used ,
64+ "cold" => Attribute :: Cold ,
65+ "const" => Attribute :: Const ,
66+ "constructor" => {
67+ let priority = if args. len ( ) == 3 &&
68+ args[ 0 ] . kind == Kind :: Punctuation && args[ 0 ] . raw . as_ref ( ) == b"(" &&
69+ args[ 1 ] . kind == Kind :: Literal &&
70+ args[ 2 ] . kind == Kind :: Punctuation && args[ 2 ] . raw . as_ref ( ) == b")" {
71+ str:: from_utf8 ( args[ 1 ] . raw . as_ref ( ) ) . ok ( ) . and_then ( |s| s. parse :: < isize > ( ) . ok ( ) )
72+ } else {
73+ None
74+ } ;
75+
76+ Attribute :: Constructor ( priority)
77+ }
78+ "destructor" => {
79+ let priority = if args. len ( ) == 3 &&
80+ args[ 0 ] . kind == Kind :: Punctuation && args[ 0 ] . raw . as_ref ( ) == b"(" &&
81+ args[ 1 ] . kind == Kind :: Literal &&
82+ args[ 2 ] . kind == Kind :: Punctuation && args[ 2 ] . raw . as_ref ( ) == b")" {
83+ str:: from_utf8 ( args[ 1 ] . raw . as_ref ( ) ) . ok ( ) . and_then ( |s| s. parse :: < isize > ( ) . ok ( ) )
84+ } else {
85+ None
86+ } ;
87+
88+ Attribute :: Destructor ( priority)
89+ }
90+ "aligned" => Attribute :: Aligned ( Vec :: from ( args) ) ,
91+ _ => Attribute :: Unexposed ( String :: from ( name) , Vec :: from ( args) ) ,
92+ }
93+ }
94+
95+ /// Parse a `Cursor` for `Vec<Attribute>`.
96+ pub fn parse ( cur : & Cursor , ctx : & BindgenContext ) -> Vec < Self > {
97+ let mut attributes = vec ! [ ] ;
98+
99+ if let Some ( tokens) = ctx. translation_unit ( ) . cexpr_tokens ( & cur) {
100+ let mut c = 0 ;
101+ let mut iter = tokens. iter ( ) ;
102+
103+ while c >= 0 {
104+ let tokens = iter. by_ref ( ) . take_while ( |ref token| {
105+ if token. kind == Kind :: Punctuation {
106+ c += match token. raw . as_ref ( ) {
107+ b"(" => 1 ,
108+ b")" => -1 ,
109+ b"," if c == 0 => return false ,
110+ _ => 0 ,
111+ }
112+ }
113+
114+ c >= 0
115+ } ) . map ( |token| token. clone ( ) ) . collect :: < Vec < Token > > ( ) ;
116+
117+ if tokens. is_empty ( ) {
118+ break
119+ } else {
120+ attributes. push ( Attribute :: new ( tokens) ) ;
121+ }
122+ }
123+ }
124+
125+ attributes
126+ }
127+
128+ /// Extract `Vec<Attribute>` from cursor's children.
129+ pub fn extract ( cur : & Cursor , ctx : & BindgenContext ) -> Vec < Self > {
130+ let mut attributes = vec ! [ ] ;
131+
132+ cur. visit ( |cur| {
133+ match cur. kind ( ) {
134+ CXCursor_UnexposedAttr => {
135+ attributes. append ( & mut Attribute :: parse ( & cur, ctx) )
136+ }
137+ _ => { }
138+ }
139+ CXChildVisit_Continue
140+ } ) ;
141+
142+ attributes
143+ }
144+
145+ /// Whether this attribute whose specific kind is not exposed.
146+ pub fn is_unexposed ( & self ) -> bool {
147+ match * self {
148+ Attribute :: Unexposed ( ..) |
149+ Attribute :: Aligned ( ..) => true ,
150+ _ => false ,
151+ }
152+ }
153+ }
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