blob: 12bfea6c551d9e158852ede6e024593ca2f159ff (
plain)
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
|
/*
* Coroutine mechanics used in PuTTY's SSH code.
*/
#ifndef PUTTY_SSHCR_H
#define PUTTY_SSHCR_H
/*
* If these macros look impenetrable to you, you might find it helpful
* to read
*
* https://www.chiark.greenend.org.uk/~sgtatham/coroutines.html
*
* which explains the theory behind these macros.
*
* In particular, if you are getting `case expression not constant'
* errors when building with MS Visual Studio, this is because MS's
* Edit and Continue debugging feature causes their compiler to
* violate ANSI C. To disable Edit and Continue debugging:
*
* - click Settings
* - select the C/C++ tab and the General category
* - under `Debug info:', select anything _other_ than `Program
* Database for Edit and Continue'.
*/
#define crBegin(v) do { int *crLine = &v; switch(v) { case 0:
#define crBeginState crBegin(s->crLine)
#define crStateP(t, v) \
struct t *s; \
if (!(v)) { s = (v) = snew(struct t); s->crLine = 0; } \
s = (v);
#define crState(t) crStateP(t, ssh->t)
#define crFinish(z) } *crLine = 0; return (z); } while (0)
#define crFinishV } *crLine = 0; return; } while (0)
#define crFinishFreed(z) } return (z); } while (0)
#define crFinishFreedV } return; } while (0)
#define crFinishFree(z) } sfree(s); return (z); } while (0)
#define crFinishFreeV } sfree(s); return; } while (0)
#define crReturn(z) \
do {\
*crLine =__LINE__; return (z); case __LINE__:;\
} while (0)
#define crReturnV \
do {\
*crLine=__LINE__; return; case __LINE__:;\
} while (0)
#define crStop(z) do{ *crLine = 0; return (z); }while(0)
#define crStopV do{ *crLine = 0; return; }while(0)
/*
* The crMaybeWaitUntil macros could have been more easily written in
* terms of the simple crReturn above, by writing things like
*
* while (!condition) { crReturn(whatever); }
*
* (or do-while in the case of crWaitUntil). But it's better to do it
* directly by writing _once_ to crLine before first testing the
* condition, because this way it's robust against the condition check
* potentially freeing the entire coroutine state structure as a side
* effect (as long as it also evaluates false if it does that),
* because we don't write into crLine between the condition evaluating
* to false and the 'return' statement.
*/
#define crMaybeWaitUntil(c) \
do { \
*crLine =__LINE__; \
case __LINE__: if (!(c)) return 0; \
} while (0)
#define crMaybeWaitUntilV(c) \
do { \
*crLine =__LINE__; \
case __LINE__: if (!(c)) return; \
} while (0)
#define crWaitUntil(c) \
do { \
*crLine =__LINE__; return; \
case __LINE__: if (!(c)) return 0; \
} while (0)
#define crWaitUntilV(c) \
do { \
*crLine =__LINE__; return; \
case __LINE__: if (!(c)) return; \
} while (0)
#endif /* PUTTY_SSHCR_H */
|
