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
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
|
This is a "function" patch for msh which is in use by some busybox
users. Unfortunately it is far too buggy to be applied, but maybe
it's a useful starting point for future work.
Function-related code is delimited by comments of the form
//funccode:start
...
//funccode:end
for ease of grepping
An example of buggy behavior:
#f() {
# echo foo
# echo test`echo bar >&2`
# echo END f
#}
function g {
# echo 2 foo
# echo 2 test`echo 2 bar >&2`
# f
echo END g
# echo "1:'$1' 2:'$2'"
}
# Even this first block fails - it does not even call functions!
# (replacing "echo END g" above with "echo END" makes it run ok)
echo DRY RUN
echo 2 foo
echo 2 test`echo 2 bar >&2`
echo END g
echo "1:'$1' 2:'$2'"
echo foo
echo test`echo bar >&2`
echo END f
echo END DRY RUN
exit
# This would fail too
g "$1-one" "two$2"
echo DONE
diff -d -urpN busybox.7/shell/msh.c busybox.8/shell/msh.c
--- busybox.7/shell/msh.c 2008-06-09 09:34:45.000000000 +0200
+++ busybox.8/shell/msh.c 2008-06-09 09:38:17.000000000 +0200
@@ -89,6 +89,14 @@ static char *itoa(int n)
//#define MSHDEBUG 4
+/* Used only in "function" support code */
+#ifdef KSDBG //funccode:start
+ #define KSDBG_PRINT_FUNCNAME fprintf(stderr, "in %s\n", __FUNCTION__)
+#else
+ #define KSDBG_PRINT_FUNCNAME ((void)0)
+#endif
+//funccode:end
+
#ifdef MSHDEBUG
static int mshdbg = MSHDEBUG;
@@ -220,6 +228,9 @@ struct op {
#define TASYNC 16 /* c & */
/* Added to support "." file expansion */
#define TDOT 17
+#define TFUNC 18 //funccode:start
+#define TRETURN 19
+ //funccode:end
/* Strings for names to make debug easier */
#ifdef MSHDEBUG
@@ -319,6 +330,27 @@ struct region {
int area;
};
+static int func_finished; //funccode:start
+struct func {
+ char* name;
+ int begin_addr; /* pos in buffer of function */
+ int end_addr;
+};
+#define MAX_FUNCS 100
+
+static struct func funcs[MAX_FUNCS];
+
+/* the max DEPTH of function call */
+#define MAX_DEPTH 100
+static struct _frame_s {
+ int argc;
+ char **argv;
+ int saved_return_addr;
+} frame[MAX_DEPTH];
+
+static void register_func(int begin, int end);
+static struct func* find_func(char* name);
+static void exec_func(struct func* f); //funccode:end
/* -------- grammar stuff -------- */
typedef union {
@@ -347,6 +379,8 @@ typedef union {
#define IN 272
/* Added for "." file expansion */
#define DOT 273
+#define FUNC 274 //funccode:start
+#define RETURN 275 //funccode:end
#define YYERRCODE 300
@@ -1722,6 +1756,40 @@ static struct op *simple(void)
(void) synio(0);
break;
+ case FUNC: { //funccode:start
+ int stop_flag;
+ int number_brace;
+ int func_begin;
+ int func_end;
+ int c;
+ while ((c = my_getc(0)) == ' ' || c == '\t'|| c == '\n') /* skip whitespace */
+ continue;
+ stop_flag = 1;
+ number_brace = 0;
+ func_begin = global_env.iobase->argp->afpos;
+ while (stop_flag) {
+ if (c == '{')
+ number_brace++;
+ if (c == '}')
+ number_brace--;
+ if (!number_brace) /* if we reach the brace of most outsite */
+ stop_flag = 0;
+ c = my_getc(0);
+ }
+ unget(c);
+ unget(c);
+ func_end = global_env.iobase->argp->afpos;
+ register_func(func_begin, func_end);
+ peeksym = 0;
+ t = NULL;
+ return t;
+ }
+ case RETURN:
+ func_finished = 1;
+ peeksym = 0;
+ t = NULL;
+ return t; //funccode:end
+
case WORD:
if (t == NULL) {
t = newtp();
@@ -2265,6 +2333,13 @@ static int yylex(int cf)
case ')':
startl = 1;
return c;
+ case '{': //funccode:start
+ c = collect(c, '}');
+ if (c != '\0')
+ return c;
+ break;
+ case '}':
+ return RETURN; //funccode:end
}
unget(c);
@@ -2293,9 +2368,172 @@ static int yylex(int cf)
}
yylval.cp = strsave(line, areanum);
+ /* To identify a subroutine */ //funccode:start
+ c = my_getc(0);
+ if (c && any(c, "(")) {
+ c = my_getc(0);
+ if (c && any(c, ")"))
+ return FUNC;
+ zzerr();
+ } else
+ unget(c);
+ /* read the first char */
+ /* To identify a function */
+ if (strcmp(yylval.cp, "function") == 0) {
+ int ret = yylex(0);
+ /* read the function name after "function" */
+ if (ret == WORD)
+ return (FUNC);
+ zzerr();
+ }
+ {
+ struct func* f = find_func(yylval.cp);
+ if (f != NULL) {
+ exec_func(f);
+ return RETURN;
+ }
+ }
+ if (yylval.cp != NULL && strcmp(yylval.cp, "return") == 0) {
+ return RETURN;
+ } //funccode:end
return WORD;
}
+static void register_func(int begin, int end) //funccode:start
+{
+ struct func *p;
+ int i;
+ for (i = 0; i < MAX_FUNCS; i++) {
+ if (funcs[i].name == NULL) {
+ p = &funcs[i];
+ break;
+ }
+ }
+ if (i == MAX_FUNCS) {
+ fprintf(stderr, "Too much functions beyond limit\n");
+ leave();
+ }
+ p->name = xstrdup(yylval.cp);
+ //fprintf(stderr, "register function,%d,%d,%s\n", begin, end, p->name);
+ KSDBG_PRINT_FUNCNAME;
+ /* io stream */
+ p->begin_addr = begin;
+ p->end_addr = end;
+}
+
+static struct func* find_func(char* name)
+{
+ int i;
+ for (i = 0; i < MAX_FUNCS; i++) {
+ if (funcs[i].name == NULL)
+ continue;
+ if (!strcmp(funcs[i].name, name))
+ return &funcs[i];
+ }
+ KSDBG_PRINT_FUNCNAME;
+ //fprintf(stderr, "not found the function %s\n", name);
+ return NULL;
+ //zzerr();
+}
+
+/* Begin to execute the function */
+static int cur_frame = 0;
+
+static void exec_func(struct func* f)
+{
+ int c;
+ int temp_argc;
+ char** temp_argv;
+ struct iobuf *bp;
+
+ /* create a new frame, save the argument and return address to this frame */
+ frame[cur_frame].argc = dolc;
+ frame[cur_frame].argv = dolv;
+
+ cur_frame++;
+ /* do some argment parse and set arguments */
+ temp_argv = xmalloc(sizeof(char *));
+ temp_argv[0] = xstrdup(f->name);
+ temp_argc = 0;
+ global_env.iop->argp->afpos--;
+ global_env.iop->argp->afbuf->bufp--;
+// unget(c);
+ while (((c = yylex(0)) != '\n') && (yylval.cp != NULL)) {
+ temp_argc++;
+ temp_argv = xrealloc(temp_argv, sizeof(char *) * (temp_argc+1));
+ /* parse $ var if passed argument is a variable */
+ if (yylval.cp[0] == '$') {
+ struct var *arg = lookup(&yylval.cp[1]);
+ temp_argv[temp_argc] = xstrdup(arg->value);
+ //fprintf(stderr, "arg->value=%s\n", arg->value);
+ } else {
+ temp_argv[temp_argc] = xstrdup(yylval.cp);
+ //fprintf(stderr, "ARG:%s\n", yylval.cp);
+ }
+ }
+ /*
+ global_env.iop->argp->afpos--;
+ global_env.iop->argp->afbuf->bufp--;
+ */
+ dolc = temp_argc;
+ dolv = temp_argv;
+ //unget(c);
+ //while ((c = my_getc(0)) == ' ' || c == '\t') /* Skip whitespace */
+ // continue;
+ //unget(c);
+ frame[cur_frame].saved_return_addr = global_env.iop->argp->afpos;
+
+ /* get function begin address and execute this function */
+
+ bp = global_env.iop->argp->afbuf;
+ bp->bufp = &(bp->buf[f->begin_addr]);
+ global_env.iop->argp->afpos = f->begin_addr;
+
+ /* func_finished=0 means we are in a function and func_finished=1 means we are executing a function */
+ func_finished = 0;
+
+ //fprintf(stderr, "exec function %s\n", f->name);
+ KSDBG_PRINT_FUNCNAME;
+ for (;;) {
+ //fprintf(stderr, "afpos=%d,%s\n", global_env.iop->argp->afpos, yylval.cp);
+ if (global_env.iop->argp->afpos == f->end_addr)
+ break;
+ onecommand();
+ /* we return from a function, when func_finished = 1 */
+ if (func_finished)
+ break;
+ }
+
+ {
+ //fprintf(stderr, "%s is finished @%d!\n", f->name, global_env.iop->argp->afpos);
+ int ret = frame[cur_frame].saved_return_addr;
+ /* workaround code for \n */
+ if (dolc)
+ ret--;
+ /* get return address from current frame and jump to */
+ global_env.iop->argp->afpos = ret;
+ global_env.iop->argp->afbuf->bufp = &(global_env.iop->argp->afbuf->buf[ret]);
+ }
+ /*
+ fprintf(stderr, "******** after execution ********************\n");
+ fprintf(stderr, " %s \n############# %d\n", global_env.iop->argp->afbuf->bufp, ret);
+ fprintf(stderr, "*******************************\n");
+ */
+ /* we return to previous frame */
+ cur_frame--;
+ /* free some space occupied by argument */
+ while (dolc--)
+ free(dolv[dolc]);
+ free(dolv);
+
+ /* recover argument for last function */
+ dolv = frame[cur_frame].argv;
+ dolc = frame[cur_frame].argc;
+ /* If we are not in the outest frame, we should set
+ * func_finished to 0 that means we still in some function */
+ if (cur_frame != 0)
+ func_finished = 0;
+} //funccode:end
static int collect(int c, int c1)
{
@@ -2601,6 +2839,10 @@ static int execute(struct op *t, int *pi
execute(t->right->right, pin, pout, /* no_fork: */ 0);
}
break;
+ case TFUNC: //funccode:start
+ break;
+ case TRETURN:
+ break; //funccode:end
case TCASE:
cp = evalstr(t->str, DOSUB | DOTRIM);
|