Commit | Line | Data |
---|---|---|
f5f1c911 | 1 | #ifndef lint |
184d26e1 | 2 | static char sccsid[] = "@(#)expr.c 1.2 (Berkeley) %G%"; |
f5f1c911 SL |
3 | #endif |
4 | /* | |
5 | * | |
6 | * UNIX debugger | |
7 | * | |
8 | */ | |
9 | ||
10 | #include "defs.h" | |
11 | ||
12 | MSG BADSYM; | |
13 | MSG BADVAR; | |
14 | MSG BADKET; | |
15 | MSG BADSYN; | |
16 | MSG NOCFN; | |
17 | MSG NOADR; | |
18 | MSG BADLOC; | |
19 | ||
20 | ADDR lastframe; | |
21 | ADDR savlastf; | |
22 | ADDR savframe; | |
23 | ADDR savpc; | |
24 | ADDR callpc; | |
25 | ||
26 | ||
27 | ||
28 | CHAR *lp; | |
29 | INT radix; | |
30 | STRING errflg; | |
31 | ADDR localval; | |
32 | CHAR isymbol[1024]; | |
33 | ||
34 | CHAR lastc,peekc; | |
35 | ||
36 | L_INT dot; | |
37 | L_INT ditto; | |
38 | INT dotinc; | |
39 | L_INT var[]; | |
40 | L_INT expv; | |
41 | ||
42 | ||
43 | ||
44 | ||
45 | expr(a) | |
46 | { /* term | term dyadic expr | */ | |
47 | REG rc; | |
48 | REG L_INT lhs; | |
49 | ||
50 | rdc(); lp--; rc=term(a); | |
51 | ||
52 | WHILE rc | |
53 | DO lhs = expv; | |
54 | ||
55 | switch ((int)readchar()) { | |
56 | ||
57 | case '+': | |
58 | term(a|1); expv += lhs; break; | |
59 | ||
60 | case '-': | |
61 | term(a|1); expv = lhs - expv; break; | |
62 | ||
63 | case '#': | |
64 | term(a|1); expv = round(lhs,expv); break; | |
65 | ||
66 | case '*': | |
67 | term(a|1); expv *= lhs; break; | |
68 | ||
69 | case '%': | |
70 | term(a|1); expv = lhs/expv; break; | |
71 | ||
72 | case '&': | |
73 | term(a|1); expv &= lhs; break; | |
74 | ||
75 | case '|': | |
76 | term(a|1); expv |= lhs; break; | |
77 | ||
78 | case ')': | |
79 | IF (a&2)==0 THEN error(BADKET); FI | |
80 | ||
81 | default: | |
82 | lp--; | |
83 | return(rc); | |
84 | } | |
85 | OD | |
86 | return(rc); | |
87 | } | |
88 | ||
89 | term(a) | |
90 | { /* item | monadic item | (expr) | */ | |
91 | ||
92 | switch ((int)readchar()) { | |
93 | ||
94 | case '*': | |
95 | term(a|1); expv=chkget(expv,DSP); return(1); | |
96 | ||
97 | case '@': | |
98 | term(a|1); expv=chkget(expv,ISP); return(1); | |
99 | ||
100 | case '-': | |
101 | term(a|1); expv = -expv; return(1); | |
102 | ||
103 | case '~': | |
104 | term(a|1); expv = ~expv; return(1); | |
105 | ||
106 | case '#': | |
107 | term(a|1); expv = !expv; return(1); | |
108 | ||
109 | case '(': | |
110 | expr(2); | |
111 | IF *lp!=')' | |
112 | THEN error(BADSYN); | |
113 | ELSE lp++; return(1); | |
114 | FI | |
115 | ||
116 | default: | |
117 | lp--; | |
118 | return(item(a)); | |
119 | } | |
120 | } | |
121 | ||
122 | item(a) | |
123 | { /* name [ . local ] | number | . | ^ | <var | <register | 'x | | */ | |
124 | REG base, d, regptr; | |
125 | CHAR savc; | |
126 | REG L_INT frame; | |
127 | register struct nlist *symp; | |
128 | ||
129 | readchar(); | |
130 | IF symchar(0) | |
131 | THEN readsym(); | |
132 | IF lastc=='.' | |
133 | THEN frame= *(ADDR *)(((ADDR)(&u))+FP); lastframe=0; | |
134 | callpc= *(ADDR *)(((ADDR)(&u))+PC); | |
135 | WHILE errflg==0 | |
136 | DO savpc=callpc; | |
137 | findsym(callpc,ISYM); | |
138 | IF eqsym(cursym->n_un.n_name,isymbol,'~') | |
139 | THEN break; | |
140 | FI | |
141 | callpc=get(frame-8, DSP); | |
142 | lastframe=frame; | |
143 | frame=get(frame, DSP)&ALIGN; | |
144 | IF frame==0 | |
145 | THEN error(NOCFN); | |
146 | FI | |
147 | OD | |
148 | savlastf=lastframe; savframe=frame; | |
149 | readchar(); | |
150 | IF symchar(0) | |
151 | THEN chkloc(expv=frame); | |
152 | FI | |
153 | ELIF (symp=lookup(isymbol))==0 THEN error(BADSYM); | |
154 | ELSE expv = symp->n_value; | |
155 | FI | |
156 | lp--; | |
157 | ||
158 | ||
159 | ELIF getnum() | |
160 | THEN ; | |
161 | ELIF lastc=='.' | |
162 | THEN readchar(); | |
163 | IF symchar(0) | |
164 | THEN lastframe=savlastf; callpc=savpc; | |
165 | chkloc(savframe); | |
166 | ELSE expv=dot; | |
167 | FI | |
168 | lp--; | |
169 | ||
170 | ELIF lastc=='"' | |
171 | THEN expv=ditto; | |
172 | ||
173 | ELIF lastc=='+' | |
174 | THEN expv=inkdot(dotinc); | |
175 | ||
176 | ELIF lastc=='^' | |
177 | THEN expv=inkdot(-dotinc); | |
178 | ||
179 | ELIF lastc=='<' | |
180 | THEN savc=rdc(); | |
184d26e1 | 181 | IF (regptr=getreg(savc)) != -1 |
f5f1c911 SL |
182 | THEN IF kcore THEN expv = *(int *)regptr; |
183 | ELSE expv= *(ADDR *)(((ADDR)(&u))+regptr); FI | |
184 | ELIF (base=varchk(savc)) != -1 | |
185 | THEN expv=var[base]; | |
186 | ELSE error(BADVAR); | |
187 | FI | |
188 | ||
189 | ELIF lastc=='\'' | |
190 | THEN d=4; expv=0; | |
191 | WHILE quotchar() | |
192 | DO IF d-- | |
193 | THEN expv <<= 8; | |
194 | expv |= lastc; | |
195 | ELSE error(BADSYN); | |
196 | FI | |
197 | OD | |
198 | ||
199 | ELIF a | |
200 | THEN error(NOADR); | |
201 | ELSE lp--; return(0); | |
202 | FI | |
203 | return(1); | |
204 | } | |
205 | ||
206 | /* service routines for expression reading */ | |
207 | getnum() | |
208 | { | |
209 | REG base,d,frpt; | |
210 | UNION{REAL r; L_INT i;} real; | |
211 | IF (base = radix) < 0 THEN base = -base; FI | |
212 | IF isdigit(lastc) | |
213 | THEN expv = 0; | |
214 | WHILE (base>10 ? isxdigit(lastc) : isdigit(lastc)) | |
215 | DO | |
216 | REG m; | |
217 | m = MAXINT/base; | |
218 | if(expv>m) | |
219 | /* avoid overflow */ | |
220 | expv = (expv-m)*base+m*base; | |
221 | else | |
222 | expv *= base; | |
223 | IF (d=convdig(lastc))>=base ORF d<0 THEN error(BADSYN); FI | |
224 | expv += d; readchar(); | |
225 | IF expv==0 | |
226 | THEN IF (lastc=='x' ORF lastc=='X') | |
227 | THEN base=16; readchar(); | |
228 | ELIF (lastc=='t' ORF lastc=='T') | |
229 | THEN base=10; readchar(); | |
230 | ELIF (lastc=='o' ORF lastc=='O') | |
231 | THEN base=8; readchar(); | |
232 | FI | |
233 | FI | |
234 | OD | |
235 | IF lastc=='.' ANDF (base==10 ORF expv==0) | |
236 | THEN real.r=expv; frpt=0; base=10; | |
237 | WHILE isdigit(readchar()) | |
238 | DO real.r *= base; frpt++; | |
239 | real.r += lastc-'0'; | |
240 | OD | |
241 | WHILE frpt-- | |
242 | DO real.r /= base; OD | |
243 | expv = real.i; | |
244 | FI | |
245 | peekc=lastc; | |
246 | return(1); | |
247 | ELSE return(0); | |
248 | FI | |
249 | } | |
250 | ||
251 | readsym() | |
252 | { | |
253 | REG char *p; | |
254 | ||
255 | p = isymbol; | |
256 | REP IF p < &isymbol[sizeof(isymbol)-1] | |
257 | THEN *p++ = lastc; | |
258 | FI | |
259 | readchar(); | |
260 | PER symchar(1) DONE | |
261 | *p++ = 0; | |
262 | } | |
263 | ||
264 | convdig(c) | |
265 | CHAR c; | |
266 | { | |
267 | IF isdigit(c) | |
268 | THEN return(c-'0'); | |
269 | ELIF isxdigit(c) | |
270 | THEN return(c-'a'+10); | |
271 | ELSE return(-1); | |
272 | FI | |
273 | } | |
274 | ||
275 | symchar(dig) | |
276 | { | |
277 | IF lastc=='\\' THEN readchar(); return(TRUE); FI | |
278 | return ( isalpha(lastc) ORF lastc=='_' ORF dig ANDF isdigit(lastc) ); | |
279 | } | |
280 | ||
281 | varchk(name) | |
282 | REG name; | |
283 | { | |
284 | IF isdigit(name) THEN return(name-'0'); FI | |
285 | IF isalpha(name) THEN return((name&037)-1+10); FI | |
286 | return(-1); | |
287 | } | |
288 | ||
289 | chkloc(frame) | |
290 | L_INT frame; | |
291 | { | |
292 | readsym(); | |
293 | REP IF localsym(frame)==0 THEN error(BADLOC); FI | |
294 | expv=localval; | |
295 | PER !eqsym(cursym->n_un.n_name,isymbol,'~') DONE | |
296 | } | |
297 | ||
298 | eqsym(s1, s2, c) | |
299 | register char *s1, *s2; | |
300 | { | |
301 | ||
302 | if (!strcmp(s1,s2)) | |
303 | return (1); | |
304 | if (*s1 == c && !strcmp(s1+1, s2)) | |
305 | return (1); | |
306 | return (0); | |
307 | } |