1 /*****************************************************************************
2
3 Copyright (c) 1998, 2014, Oracle and/or its affiliates. All Rights Reserved.
4
5 This program is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License, version 2.0,
7 as published by the Free Software Foundation.
8
9 This program is also distributed with certain software (including
10 but not limited to OpenSSL) that is licensed under separate terms,
11 as designated in a particular file or component or in included license
12 documentation. The authors of MySQL hereby grant you an additional
13 permission to link the program and your derivative works with the
14 separately licensed software that they have included with MySQL.
15
16 This program is distributed in the hope that it will be useful,
17 but WITHOUT ANY WARRANTY; without even the implied warranty of
18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
19 GNU General Public License, version 2.0, for more details.
20
21 You should have received a copy of the GNU General Public License along with
22 this program; if not, write to the Free Software Foundation, Inc.,
23 51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA
24
25 *****************************************************************************/
26
27 /**************************************************//**
28 @file eval/eval0proc.cc
29 Executes SQL stored procedures and their control structures
30
31 Created 1/20/1998 Heikki Tuuri
32 *******************************************************/
33
34 #include "eval0proc.h"
35
36 #ifdef UNIV_NONINL
37 #include "eval0proc.ic"
38 #endif
39
40 /**********************************************************************//**
41 Performs an execution step of an if-statement node.
42 @return query thread to run next or NULL */
43 que_thr_t*
if_step(que_thr_t * thr)44 if_step(
45 /*====*/
46 que_thr_t* thr) /*!< in: query thread */
47 {
48 if_node_t* node;
49 elsif_node_t* elsif_node;
50
51 ut_ad(thr);
52
53 node = static_cast<if_node_t*>(thr->run_node);
54 ut_ad(que_node_get_type(node) == QUE_NODE_IF);
55
56 if (thr->prev_node == que_node_get_parent(node)) {
57
58 /* Evaluate the condition */
59
60 eval_exp(node->cond);
61
62 if (eval_node_get_ibool_val(node->cond)) {
63
64 /* The condition evaluated to TRUE: start execution
65 from the first statement in the statement list */
66
67 thr->run_node = node->stat_list;
68
69 } else if (node->else_part) {
70 thr->run_node = node->else_part;
71
72 } else if (node->elsif_list) {
73 elsif_node = node->elsif_list;
74
75 for (;;) {
76 eval_exp(elsif_node->cond);
77
78 if (eval_node_get_ibool_val(
79 elsif_node->cond)) {
80
81 /* The condition evaluated to TRUE:
82 start execution from the first
83 statement in the statement list */
84
85 thr->run_node = elsif_node->stat_list;
86
87 break;
88 }
89
90 elsif_node = static_cast<elsif_node_t*>(
91 que_node_get_next(elsif_node));
92
93 if (elsif_node == NULL) {
94 thr->run_node = NULL;
95
96 break;
97 }
98 }
99 } else {
100 thr->run_node = NULL;
101 }
102 } else {
103 /* Move to the next statement */
104 ut_ad(que_node_get_next(thr->prev_node) == NULL);
105
106 thr->run_node = NULL;
107 }
108
109 if (thr->run_node == NULL) {
110 thr->run_node = que_node_get_parent(node);
111 }
112
113 return(thr);
114 }
115
116 /**********************************************************************//**
117 Performs an execution step of a while-statement node.
118 @return query thread to run next or NULL */
119 que_thr_t*
while_step(que_thr_t * thr)120 while_step(
121 /*=======*/
122 que_thr_t* thr) /*!< in: query thread */
123 {
124 while_node_t* node;
125
126 ut_ad(thr);
127
128 node = static_cast<while_node_t*>(thr->run_node);
129 ut_ad(que_node_get_type(node) == QUE_NODE_WHILE);
130
131 ut_ad((thr->prev_node == que_node_get_parent(node))
132 || (que_node_get_next(thr->prev_node) == NULL));
133
134 /* Evaluate the condition */
135
136 eval_exp(node->cond);
137
138 if (eval_node_get_ibool_val(node->cond)) {
139
140 /* The condition evaluated to TRUE: start execution
141 from the first statement in the statement list */
142
143 thr->run_node = node->stat_list;
144 } else {
145 thr->run_node = que_node_get_parent(node);
146 }
147
148 return(thr);
149 }
150
151 /**********************************************************************//**
152 Performs an execution step of an assignment statement node.
153 @return query thread to run next or NULL */
154 que_thr_t*
assign_step(que_thr_t * thr)155 assign_step(
156 /*========*/
157 que_thr_t* thr) /*!< in: query thread */
158 {
159 assign_node_t* node;
160
161 ut_ad(thr);
162
163 node = static_cast<assign_node_t*>(thr->run_node);
164 ut_ad(que_node_get_type(node) == QUE_NODE_ASSIGNMENT);
165
166 /* Evaluate the value to assign */
167
168 eval_exp(node->val);
169
170 eval_node_copy_val(node->var->alias, node->val);
171
172 thr->run_node = que_node_get_parent(node);
173
174 return(thr);
175 }
176
177 /**********************************************************************//**
178 Performs an execution step of a for-loop node.
179 @return query thread to run next or NULL */
180 que_thr_t*
for_step(que_thr_t * thr)181 for_step(
182 /*=====*/
183 que_thr_t* thr) /*!< in: query thread */
184 {
185 for_node_t* node;
186 que_node_t* parent;
187 lint loop_var_value;
188
189 ut_ad(thr);
190
191 node = static_cast<for_node_t*>(thr->run_node);
192
193 ut_ad(que_node_get_type(node) == QUE_NODE_FOR);
194
195 parent = que_node_get_parent(node);
196
197 if (thr->prev_node != parent) {
198
199 /* Move to the next statement */
200 thr->run_node = que_node_get_next(thr->prev_node);
201
202 if (thr->run_node != NULL) {
203
204 return(thr);
205 }
206
207 /* Increment the value of loop_var */
208
209 loop_var_value = 1 + eval_node_get_int_val(node->loop_var);
210 } else {
211 /* Initialize the loop */
212
213 eval_exp(node->loop_start_limit);
214 eval_exp(node->loop_end_limit);
215
216 loop_var_value = eval_node_get_int_val(node->loop_start_limit);
217
218 node->loop_end_value
219 = (int) eval_node_get_int_val(node->loop_end_limit);
220 }
221
222 /* Check if we should do another loop */
223
224 if (loop_var_value > node->loop_end_value) {
225
226 /* Enough loops done */
227
228 thr->run_node = parent;
229 } else {
230 eval_node_set_int_val(node->loop_var, loop_var_value);
231
232 thr->run_node = node->stat_list;
233 }
234
235 return(thr);
236 }
237
238 /**********************************************************************//**
239 Performs an execution step of an exit statement node.
240 @return query thread to run next or NULL */
241 que_thr_t*
exit_step(que_thr_t * thr)242 exit_step(
243 /*======*/
244 que_thr_t* thr) /*!< in: query thread */
245 {
246 exit_node_t* node;
247 que_node_t* loop_node;
248
249 ut_ad(thr);
250
251 node = static_cast<exit_node_t*>(thr->run_node);
252
253 ut_ad(que_node_get_type(node) == QUE_NODE_EXIT);
254
255 /* Loops exit by setting thr->run_node as the loop node's parent, so
256 find our containing loop node and get its parent. */
257
258 loop_node = que_node_get_containing_loop_node(node);
259
260 /* If someone uses an EXIT statement outside of a loop, this will
261 trigger. */
262 ut_a(loop_node);
263
264 thr->run_node = que_node_get_parent(loop_node);
265
266 return(thr);
267 }
268
269 /**********************************************************************//**
270 Performs an execution step of a return-statement node.
271 @return query thread to run next or NULL */
272 que_thr_t*
return_step(que_thr_t * thr)273 return_step(
274 /*========*/
275 que_thr_t* thr) /*!< in: query thread */
276 {
277 return_node_t* node;
278 que_node_t* parent;
279
280 ut_ad(thr);
281
282 node = static_cast<return_node_t*>(thr->run_node);
283
284 ut_ad(que_node_get_type(node) == QUE_NODE_RETURN);
285
286 parent = node;
287
288 while (que_node_get_type(parent) != QUE_NODE_PROC) {
289
290 parent = que_node_get_parent(parent);
291 }
292
293 ut_a(parent);
294
295 thr->run_node = que_node_get_parent(parent);
296
297 return(thr);
298 }
299