ref: 4821c261c4cea895ddcbd7c70bc71103c9a2763b
dir: /sys/src/cmd/acid/lex.c/
#include <u.h> #include <libc.h> #include <bio.h> #include <ctype.h> #include <mach.h> #define Extern extern #include "acid.h" #include "y.tab.h" struct keywd { char *name; int terminal; } keywds[] = { "do", Tdo, "if", Tif, "then", Tthen, "else", Telse, "while", Twhile, "loop", Tloop, "head", Thead, "tail", Ttail, "append", Tappend, "defn", Tfn, "return", Tret, "local", Tlocal, "aggr", Tcomplex, "union", Tcomplex, "adt", Tcomplex, "complex", Tcomplex, "delete", Tdelete, "whatis", Twhat, "eval", Teval, "builtin", Tbuiltin, 0, 0 }; char cmap[256] = { ['0'] '\0'+1, ['n'] '\n'+1, ['r'] '\r'+1, ['t'] '\t'+1, ['b'] '\b'+1, ['f'] '\f'+1, ['a'] '\a'+1, ['v'] '\v'+1, ['\\'] '\\'+1, ['"'] '"'+1, }; void kinit(void) { int i; for(i = 0; keywds[i].name; i++) enter(keywds[i].name, keywds[i].terminal); } typedef struct IOstack IOstack; struct IOstack { char *name; int line; char *text; char *ip; Biobuf *fin; IOstack *prev; }; IOstack *lexio; void pushfile(char *file) { Biobuf *b; IOstack *io; if(file) b = Bopen(file, OREAD); else{ b = Bopen("/fd/0", OREAD); file = "<stdin>"; } if(b == 0) error("pushfile: %s: %r", file); io = malloc(sizeof(IOstack)); if(io == 0) fatal("no memory"); io->name = strdup(file); if(io->name == 0) fatal("no memory"); io->line = line; line = 1; io->text = 0; io->fin = b; io->prev = lexio; lexio = io; } void pushstr(Node *s) { IOstack *io; io = malloc(sizeof(IOstack)); if(io == 0) fatal("no memory"); io->line = line; line = 1; io->name = strdup("<string>"); if(io->name == 0) fatal("no memory"); io->line = line; line = 1; io->text = strdup(s->string->string); if(io->text == 0) fatal("no memory"); io->ip = io->text; io->fin = 0; io->prev = lexio; lexio = io; } void restartio(void) { Bflush(lexio->fin); Binit(lexio->fin, 0, OREAD); } int popio(void) { IOstack *s; if(lexio == 0) return 0; if(lexio->prev == 0){ if(lexio->fin) restartio(); return 0; } if(lexio->fin) Bterm(lexio->fin); else free(lexio->text); free(lexio->name); line = lexio->line; s = lexio; lexio = s->prev; free(s); return 1; } int Lfmt(Fmt *f) { int i; char buf[1024]; IOstack *e; e = lexio; if(e) { i = snprint(buf, sizeof(buf), "%s:%d", e->name, line); while(e->prev) { e = e->prev; if(initialising && e->prev == 0) break; i += snprint(buf+i, sizeof(buf)-i, " [%s:%d]", e->name, e->line); } } else snprint(buf, sizeof(buf), "no file:0"); fmtstrcpy(f, buf); return 0; } void unlexc(int s) { if(s == '\n') line--; if(lexio->fin) Bungetc(lexio->fin); else lexio->ip--; } int lexc(void) { int c; if(lexio->fin) { c = Bgetc(lexio->fin); if(gotint) error("interrupt"); return c; } c = *lexio->ip++; if(c == 0) return -1; return c; } int escchar(char c) { int n; char buf[Strsize]; if(c >= '0' && c <= '9') { n = 1; buf[0] = c; for(;;) { c = lexc(); if(c == Eof) error("%d: <eof> in escape sequence", line); if(strchr("0123456789xX", c) == 0) { unlexc(c); break; } if(n >= Strsize) error("string escape too long"); buf[n++] = c; } buf[n] = '\0'; return strtol(buf, 0, 0); } n = cmap[c]; if(n == 0) return c; return n-1; } void eatstring(void) { int esc, c, cnt; char buf[Strsize]; esc = 0; for(cnt = 0;;) { c = lexc(); switch(c) { case Eof: error("%d: <eof> in string constant", line); case '\n': error("newline in string constant"); goto done; case '\\': if(esc) goto Default; esc = 1; break; case '"': if(esc == 0) goto done; /* Fall through */ default: Default: if(esc) { c = escchar(c); esc = 0; } buf[cnt++] = c; break; } if(cnt >= Strsize) error("string token too long"); } done: buf[cnt] = '\0'; yylval.string = strnode(buf); } void eatnl(void) { int c; line++; for(;;) { c = lexc(); if(c == Eof) error("eof in comment"); if(c == '\n') return; } } int yylex(void) { int c; extern char vfmt[]; loop: Bflush(bout); c = lexc(); switch(c) { case Eof: if(gotint) { gotint = 0; stacked = 0; Bprint(bout, "\nacid: "); goto loop; } return Eof; case '"': eatstring(); return Tstring; case ' ': case '\t': goto loop; case '/': c = lexc(); if(c != '/'){ unlexc(c); return '/'; } eatnl(); case '\n': line++; if(interactive == 0) goto loop; if(stacked) { print("\t"); goto loop; } return ';'; case '.': c = lexc(); unlexc(c); if(isdigit(c)) return numsym('.'); return '.'; case '(': case ')': case '[': case ']': case ';': case ':': case ',': case '~': case '?': case '*': case '@': case '^': case '%': return c; case '{': stacked++; return c; case '}': stacked--; return c; case '\\': c = lexc(); if(strchr(vfmt, c) == 0) { unlexc(c); return '\\'; } yylval.ival = c; return Tfmt; case '!': c = lexc(); if(c == '=') return Tneq; unlexc(c); return '!'; case '+': c = lexc(); if(c == '+') return Tinc; unlexc(c); return '+'; case '\'': c = lexc(); if(c == '\\') yylval.ival = escchar(lexc()); else yylval.ival = c; c = lexc(); if(c != '\'') { error("missing '"); unlexc(c); } return Tconst; case '&': c = lexc(); if(c == '&') return Tandand; unlexc(c); return '&'; case '=': c = lexc(); if(c == '=') return Teq; unlexc(c); return '='; case '|': c = lexc(); if(c == '|') return Toror; unlexc(c); return '|'; case '<': c = lexc(); if(c == '=') return Tleq; if(c == '<') return Tlsh; unlexc(c); return '<'; case '>': c = lexc(); if(c == '=') return Tgeq; if(c == '>') return Trsh; unlexc(c); return '>'; case '-': c = lexc(); if(c == '>') return Tindir; if(c == '-') return Tdec; unlexc(c); return '-'; default: return numsym(c); } } int numsym(char first) { int c, isbin, isfloat, ishex; char *sel, *p; Lsym *s; symbol[0] = first; p = symbol; ishex = 0; isbin = 0; isfloat = 0; if(first == '.') isfloat = 1; if(isdigit(*p++) || isfloat) { for(;;) { c = lexc(); if(c < 0) error("%d: <eof> eating symbols", line); if(c == '\n') line++; sel = "01234567890.xb"; if(ishex) sel = "01234567890abcdefABCDEF"; else if(isbin) sel = "01"; else if(isfloat) sel = "01234567890eE-+"; if(strchr(sel, c) == 0) { unlexc(c); break; } if(c == '.') isfloat = 1; if(!isbin && c == 'x') ishex = 1; if(!ishex && c == 'b') isbin = 1; *p++ = c; } *p = '\0'; if(isfloat) { yylval.fval = atof(symbol); return Tfconst; } if(isbin) yylval.ival = strtoull(symbol+2, 0, 2); else yylval.ival = strtoull(symbol, 0, 0); return Tconst; } for(;;) { c = lexc(); if(c < 0) error("%d <eof> eating symbols", line); if(c == '\n') line++; if(c != '_' && c != '$' && c <= '~' && !isalnum(c)) { /* checking against ~ lets UTF names through */ unlexc(c); break; } *p++ = c; } *p = '\0'; s = look(symbol); if(s == 0) s = enter(symbol, Tid); yylval.sym = s; return s->lexval; } Lsym* enter(char *name, int t) { Lsym *s; uint h; char *p; Value *v; h = 0; for(p = name; *p; p++) h = h*3 + *p; h %= Hashsize; s = gmalloc(sizeof(Lsym)); memset(s, 0, sizeof(Lsym)); s->name = strdup(name); s->hash = hash[h]; hash[h] = s; s->lexval = t; v = gmalloc(sizeof(Value)); memset(v, 0, sizeof(Value)); v->fmt = 'X'; v->type = TINT; s->v = v; return s; } Lsym* look(char *name) { Lsym *s; uint h; char *p; h = 0; for(p = name; *p; p++) h = h*3 + *p; h %= Hashsize; for(s = hash[h]; s; s = s->hash) if(strcmp(name, s->name) == 0) return s; return 0; } Lsym* mkvar(char *s) { Lsym *l; l = look(s); if(l == 0) l = enter(s, Tid); return l; }