blob: 4df72d4f4d1f4e6ef747a955cf6be417caf77bdb (
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
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
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
|
/*-------------------------------------------------------------------------
* A stack of automaton states to handle nested conditionals.
*
* Copyright (c) 2000-2020, PostgreSQL Global Development Group
*
* src/fe_utils/conditional.c
*
*-------------------------------------------------------------------------
*/
#include "postgres_fe.h"
#include "fe_utils/conditional.h"
/*
* create stack
*/
ConditionalStack
conditional_stack_create(void)
{
ConditionalStack cstack = pg_malloc(sizeof(ConditionalStackData));
cstack->head = NULL;
return cstack;
}
/*
* destroy stack
*/
void
conditional_stack_destroy(ConditionalStack cstack)
{
while (conditional_stack_pop(cstack))
continue;
free(cstack);
}
/*
* Create a new conditional branch.
*/
void
conditional_stack_push(ConditionalStack cstack, ifState new_state)
{
IfStackElem *p = (IfStackElem *) pg_malloc(sizeof(IfStackElem));
p->if_state = new_state;
p->query_len = -1;
p->paren_depth = -1;
p->next = cstack->head;
cstack->head = p;
}
/*
* Destroy the topmost conditional branch.
* Returns false if there was no branch to end.
*/
bool
conditional_stack_pop(ConditionalStack cstack)
{
IfStackElem *p = cstack->head;
if (!p)
return false;
cstack->head = cstack->head->next;
free(p);
return true;
}
/*
* Returns current stack depth, for debugging purposes.
*/
int
conditional_stack_depth(ConditionalStack cstack)
{
if (cstack == NULL)
return -1;
else
{
IfStackElem *p = cstack->head;
int depth = 0;
while (p != NULL)
{
depth++;
p = p->next;
}
return depth;
}
}
/*
* Fetch the current state of the top of the stack.
*/
ifState
conditional_stack_peek(ConditionalStack cstack)
{
if (conditional_stack_empty(cstack))
return IFSTATE_NONE;
return cstack->head->if_state;
}
/*
* Change the state of the topmost branch.
* Returns false if there was no branch state to set.
*/
bool
conditional_stack_poke(ConditionalStack cstack, ifState new_state)
{
if (conditional_stack_empty(cstack))
return false;
cstack->head->if_state = new_state;
return true;
}
/*
* True if there are no active \if-blocks.
*/
bool
conditional_stack_empty(ConditionalStack cstack)
{
return cstack->head == NULL;
}
/*
* True if we should execute commands normally; that is, the current
* conditional branch is active, or there is no open \if block.
*/
bool
conditional_active(ConditionalStack cstack)
{
ifState s = conditional_stack_peek(cstack);
return s == IFSTATE_NONE || s == IFSTATE_TRUE || s == IFSTATE_ELSE_TRUE;
}
/*
* Save current query buffer length in topmost stack entry.
*/
void
conditional_stack_set_query_len(ConditionalStack cstack, int len)
{
Assert(!conditional_stack_empty(cstack));
cstack->head->query_len = len;
}
/*
* Fetch last-recorded query buffer length from topmost stack entry.
* Will return -1 if no stack or it was never saved.
*/
int
conditional_stack_get_query_len(ConditionalStack cstack)
{
if (conditional_stack_empty(cstack))
return -1;
return cstack->head->query_len;
}
/*
* Save current parenthesis nesting depth in topmost stack entry.
*/
void
conditional_stack_set_paren_depth(ConditionalStack cstack, int depth)
{
Assert(!conditional_stack_empty(cstack));
cstack->head->paren_depth = depth;
}
/*
* Fetch last-recorded parenthesis nesting depth from topmost stack entry.
* Will return -1 if no stack or it was never saved.
*/
int
conditional_stack_get_paren_depth(ConditionalStack cstack)
{
if (conditional_stack_empty(cstack))
return -1;
return cstack->head->paren_depth;
}
|
