Commit | Line | Data |
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d89e5cdd BJ |
1 | # |
2 | /* | |
3 | * | |
4 | * UNIX debugger | |
5 | * | |
6 | */ | |
7 | ||
8 | #include "defs.h" | |
9 | SCCSID(@(#)expr.c 2.5); | |
10 | ||
11 | ||
12 | MSG BADSYM; | |
13 | MSG BADVAR; | |
14 | MSG BADKET; | |
15 | MSG BADSYN; | |
16 | MSG NOCFN; | |
17 | MSG NOADR; | |
18 | MSG BADLOC; | |
19 | ||
20 | SYMTAB symbol; | |
21 | ADDR lastframe; | |
22 | ADDR savlastf; | |
23 | ADDR savframe; | |
24 | ADDR savpc; | |
25 | ADDR callpc; | |
26 | ||
27 | ||
28 | ||
29 | CHAR *lp; | |
30 | INT radix; | |
31 | STRING errflg; | |
32 | L_INT localval; | |
33 | CHAR isymbol[8]; | |
34 | ||
35 | CHAR lastc,peekc; | |
36 | char u[ctob(UPAGES)]; /* struct user u; */ | |
37 | ||
38 | L_INT dot; | |
39 | L_INT ditto; | |
40 | INT dotinc; | |
41 | L_INT var[]; | |
42 | L_INT expv; | |
43 | ||
44 | ||
45 | ||
46 | ||
47 | expr(a) | |
48 | { /* term | term dyadic expr | */ | |
49 | INT rc; | |
50 | L_INT lhs; | |
51 | ||
52 | rdc(); lp--; rc=term(a); | |
53 | ||
54 | WHILE rc | |
55 | DO lhs = expv; | |
56 | ||
57 | switch ((int)readchar()) { | |
58 | ||
59 | case '+': | |
60 | term(a|1); expv += lhs; break; | |
61 | ||
62 | case '-': | |
63 | term(a|1); expv = lhs - expv; break; | |
64 | ||
65 | case '#': | |
66 | term(a|1); expv = round(lhs,expv); break; | |
67 | ||
68 | case '*': | |
69 | term(a|1); expv *= lhs; break; | |
70 | ||
71 | case '%': | |
72 | term(a|1); expv = lhs/expv; break; | |
73 | ||
74 | case '&': | |
75 | term(a|1); expv &= lhs; break; | |
76 | ||
77 | case '|': | |
78 | term(a|1); expv |= lhs; break; | |
79 | ||
80 | case ')': | |
81 | IF (a&2)==0 THEN error(BADKET); FI | |
82 | ||
83 | default: | |
84 | lp--; | |
85 | return(rc); | |
86 | } | |
87 | OD | |
88 | return(rc); | |
89 | } | |
90 | ||
91 | term(a) | |
92 | { /* item | monadic item | (expr) | */ | |
93 | ||
94 | switch ((int)readchar()) { | |
95 | ||
96 | case '*': | |
97 | term(a|1); expv=chkget(expv,DSP); return(1); | |
98 | ||
99 | case '@': | |
100 | term(a|1); expv=chkget(expv,ISP); return(1); | |
101 | ||
102 | case '-': | |
103 | term(a|1); expv = -expv; return(1); | |
104 | ||
105 | case '~': | |
106 | term(a|1); expv = ~expv; return(1); | |
107 | ||
108 | case '(': | |
109 | expr(2); | |
110 | IF *lp!=')' | |
111 | THEN error(BADSYN); | |
112 | ELSE lp++; return(1); | |
113 | FI | |
114 | ||
115 | default: | |
116 | lp--; | |
117 | return(item(a)); | |
118 | } | |
119 | } | |
120 | ||
121 | item(a) | |
122 | { /* name [ . local ] | number | . | ^ | <var | <register | 'x | | */ | |
123 | INT base, d, regptr; | |
124 | CHAR savc; | |
125 | BOOL hex; | |
126 | L_INT frame; | |
127 | SYMPTR symp; | |
128 | ||
129 | hex=FALSE; | |
130 | ||
131 | readchar(); | |
132 | IF symchar(0) | |
133 | THEN readsym(); | |
134 | IF lastc=='.' | |
135 | THEN frame= *(ADDR *)(((ADDR)&u[0])+FP); lastframe=0; | |
136 | callpc= *(ADDR *)(((ADDR)&u[0])+PC); | |
137 | WHILE errflg==0 | |
138 | DO savpc=callpc; | |
139 | findsym(callpc,ISYM); | |
140 | IF eqsym(symbol.symc,isymbol,'~') | |
141 | THEN break; | |
142 | FI | |
143 | callpc=get(frame+16, DSP); | |
144 | lastframe=frame; | |
145 | frame=get(frame+12,DSP)&EVEN; | |
146 | IF frame==0 | |
147 | THEN error(NOCFN); | |
148 | FI | |
149 | OD | |
150 | savlastf=lastframe; savframe=frame; | |
151 | readchar(); | |
152 | IF symchar(0) | |
153 | THEN chkloc(expv=frame); | |
154 | FI | |
155 | ELIF (symp=lookupsym(isymbol))==0 THEN error(BADSYM); | |
156 | ELSE expv = symp->symv; | |
157 | FI | |
158 | lp--; | |
159 | ||
160 | ||
161 | ELIF getnum(readchar) | |
162 | THEN ; | |
163 | ELIF lastc=='.' | |
164 | THEN readchar(); | |
165 | IF symchar(0) | |
166 | THEN lastframe=savlastf; callpc=savpc; | |
167 | chkloc(savframe); | |
168 | ELSE expv=dot; | |
169 | FI | |
170 | lp--; | |
171 | ||
172 | ELIF lastc=='"' | |
173 | THEN expv=ditto; | |
174 | ||
175 | ELIF lastc=='+' | |
176 | THEN expv=inkdot(dotinc); | |
177 | ||
178 | ELIF lastc=='^' | |
179 | THEN expv=inkdot(-dotinc); | |
180 | ||
181 | ELIF lastc=='<' | |
182 | THEN savc=rdc(); | |
183 | IF regptr=getreg(savc) | |
184 | THEN expv= * (ADDR *)(((ADDR)&u[0])+regptr); | |
185 | ELIF (base=varchk(savc)) != -1 | |
186 | THEN expv=var[base]; | |
187 | ELSE error(BADVAR); | |
188 | FI | |
189 | ||
190 | ELIF lastc=='\'' | |
191 | THEN d=4; expv=0; | |
192 | WHILE quotchar() | |
193 | DO IF d-- | |
194 | THEN IF d==1 THEN expv <<=16; FI | |
195 | expv |= ((d&1)?lastc:lastc<<8); | |
196 | ELSE error(BADSYN); | |
197 | FI | |
198 | OD | |
199 | ||
200 | ELIF a | |
201 | THEN error(NOADR); | |
202 | ELSE lp--; return(0); | |
203 | FI | |
204 | return(1); | |
205 | } | |
206 | ||
207 | /* service routines for expression reading */ | |
208 | getnum(rdf) int (*rdf)(); | |
209 | { | |
210 | INT base,d,frpt; | |
211 | BOOL hex; | |
212 | UNION{REAL r; L_INT i;} real; | |
213 | IF digit(lastc) ORF (hex=TRUE, lastc=='#' ANDF hexdigit((*rdf)())) | |
214 | THEN expv = 0; | |
215 | base = (hex ? 16 : radix); | |
216 | WHILE (base>10 ? hexdigit(lastc) : digit(lastc)) | |
217 | DO expv = (base==16 ? expv<<4 : expv*base); | |
218 | IF (d=convdig(lastc))>=base THEN error(BADSYN); FI | |
219 | expv += d; (*rdf)(); | |
220 | IF expv==0 | |
221 | THEN IF (lastc=='x' ORF lastc=='X') | |
222 | THEN hex=TRUE; base=16; (*rdf)(); | |
223 | ELIF (lastc=='t' ORF lastc=='T') | |
224 | THEN hex=FALSE; base=10; (*rdf)(); | |
225 | ELIF (lastc=='o' ORF lastc=='O') | |
226 | THEN hex=FALSE; base=8; (*rdf)(); | |
227 | FI | |
228 | FI | |
229 | OD | |
230 | IF lastc=='.' ANDF (base==10 ORF expv==0) ANDF !hex | |
231 | THEN real.r=expv; frpt=0; base=10; | |
232 | WHILE digit((*rdf)()) | |
233 | DO real.r *= base; frpt++; | |
234 | real.r += lastc-'0'; | |
235 | OD | |
236 | WHILE frpt-- | |
237 | DO real.r /= base; OD | |
238 | expv = real.i; | |
239 | FI | |
240 | peekc=lastc; | |
241 | /* lp--; */ | |
242 | return(1); | |
243 | ELSE return(0); | |
244 | FI | |
245 | } | |
246 | ||
247 | readsym() | |
248 | { | |
249 | REG char *p; | |
250 | ||
251 | p = isymbol; | |
252 | REP IF p < &isymbol[8] | |
253 | THEN *p++ = lastc; | |
254 | FI | |
255 | readchar(); | |
256 | PER symchar(1) DONE | |
257 | WHILE p < &isymbol[8] DO *p++ = 0; OD | |
258 | } | |
259 | ||
260 | SYMPTR lookupsym(symstr) | |
261 | STRING symstr; | |
262 | { | |
263 | SYMPTR symp; | |
264 | symset(); | |
265 | WHILE (symp=symget()) | |
266 | #ifndef EDDT | |
267 | DO IF (symp->symf&SYMCHK)==symp->symf | |
268 | ANDF eqsym(symp->symc, symstr,'_') | |
269 | #else | |
270 | DO IF eqsym(symp->symc, symstr, '_') | |
271 | #endif | |
272 | THEN return(symp); | |
273 | FI | |
274 | OD | |
275 | return(0); | |
276 | } | |
277 | ||
278 | hexdigit(c) | |
279 | CHAR c; | |
280 | { return((c>='0' ANDF c<='9') ORF (c>='a' ANDF c<='f')); | |
281 | } | |
282 | ||
283 | convdig(c) | |
284 | CHAR c; | |
285 | { | |
286 | IF digit(c) | |
287 | THEN return(c-'0'); | |
288 | ELIF hexdigit(c) | |
289 | THEN return(c-'a'+10); | |
290 | ELSE return(17); | |
291 | FI | |
292 | } | |
293 | ||
294 | digit(c) char c; {return(c>='0' ANDF c<='9');} | |
295 | ||
296 | letter(c) char c; {return(c>='a' ANDF c<='z' ORF c>='A' ANDF c<='Z');} | |
297 | ||
298 | symchar(dig) | |
299 | { | |
300 | IF lastc=='\\' THEN readchar(); return(TRUE); FI | |
301 | return( letter(lastc) ORF lastc=='_' ORF dig ANDF digit(lastc) ); | |
302 | } | |
303 | ||
304 | varchk(name) | |
305 | { | |
306 | IF digit(name) THEN return(name-'0'); FI | |
307 | IF letter(name) THEN return((name&037)-1+10); FI | |
308 | return(-1); | |
309 | } | |
310 | ||
311 | chkloc(frame) | |
312 | L_INT frame; | |
313 | { | |
314 | readsym(); | |
315 | REP IF localsym(frame)==0 THEN error(BADLOC); FI | |
316 | expv=localval; | |
317 | PER !eqsym(symbol.symc,isymbol,'~') DONE | |
318 | } | |
319 | ||
320 | eqsym(s1, s2, c) | |
321 | REG STRING s1, s2; | |
322 | CHAR c; | |
323 | { | |
324 | IF eqstr(s1,s2) | |
325 | THEN return(TRUE); | |
326 | ELIF *s1==c | |
327 | THEN CHAR s3[8]; | |
328 | REG INT i; | |
329 | ||
330 | s3[0]=c; | |
331 | FOR i=1; i<8; i++ | |
332 | DO s3[i] = *s2++; OD | |
333 | ||
334 | return(eqstr(s1,s3)); | |
335 | FI | |
336 | } |