ref: 83246e296ea433b65b9d295b5e08fedd39ff1ab7
dir: /appl/cmd/limbo/lex.b/
Leof: con -1; Linestart: con 0; Mlower, Mupper, Munder, Mdigit, Msign, Mexp, Mhex, Mradix: con byte 1 << iota; Malpha: con Mupper|Mlower|Munder; HashSize: con 1024; Keywd: adt { name: string; token: int; }; # # internals # savec: int; files: array of ref File; # files making up the module, sorted by absolute line nfiles: int; lastfile := 0; # index of last file looked up incpath := array[MaxIncPath] of string; symbols := array[HashSize] of ref Sym; strings := array[HashSize] of ref Sym; map := array[256] of byte; bins := array [MaxInclude] of ref Iobuf; bin: ref Iobuf; linestack := array[MaxInclude] of (int, int); lineno: int; linepos: int; bstack: int; lasttok: int; lastyylval: YYSTYPE; dowarn: int; maxerr: int; dosym: int; toterrors: int; fabort: int; srcdir: string; outfile: string; stderr: ref Sys->FD; dontinline: int; escmap := array[256] of { '\'' => '\'', '"' => '"', '\\' => '\\', 'a' => '\a', 'b' => '\b', 'f' => '\f', 'n' => '\n', 'r' => '\r', 't' => '\t', 'v' => '\v', '0' => '\u0000', * => -1 }; unescmap := array[256] of { '\'' => '\'', '"' => '"', '\\' => '\\', '\a' => 'a', '\b' => 'b', '\f' => 'f', '\n' => 'n', '\r' => 'r', '\t' => 't', '\v' => 'v', '\u0000' => '0', * => 0 }; keywords := array [] of { Keywd("adt", Ladt), Keywd("alt", Lalt), Keywd("array", Larray), Keywd("big", Ltid), Keywd("break", Lbreak), Keywd("byte", Ltid), Keywd("case", Lcase), Keywd("chan", Lchan), Keywd("con", Lcon), Keywd("continue", Lcont), Keywd("cyclic", Lcyclic), Keywd("do", Ldo), Keywd("dynamic", Ldynamic), Keywd("else", Lelse), Keywd("exception", Lexcept), Keywd("exit", Lexit), Keywd("fixed", Lfix), Keywd("fn", Lfn), Keywd("for", Lfor), Keywd("hd", Lhd), Keywd("if", Lif), Keywd("implement", Limplement), Keywd("import", Limport), Keywd("include", Linclude), Keywd("int", Ltid), Keywd("len", Llen), Keywd("list", Llist), Keywd("load", Lload), Keywd("module", Lmodule), Keywd("nil", Lnil), Keywd("of", Lof), Keywd("or", Lor), Keywd("pick", Lpick), Keywd("raise", Lraise), Keywd("raises", Lraises), Keywd("real", Ltid), Keywd("ref", Lref), Keywd("return", Lreturn), Keywd("self", Lself), Keywd("spawn", Lspawn), Keywd("string", Ltid), Keywd("tagof", Ltagof), Keywd("tl", Ltl), Keywd("to", Lto), Keywd("type", Ltype), Keywd("while", Lwhile), }; tokwords := array[] of { Keywd("&=", Landeq), Keywd("|=", Loreq), Keywd("^=", Lxoreq), Keywd("<<=", Llsheq), Keywd(">>=", Lrsheq), Keywd("+=", Laddeq), Keywd("-=", Lsubeq), Keywd("*=", Lmuleq), Keywd("/=", Ldiveq), Keywd("%=", Lmodeq), Keywd("**=", Lexpeq), Keywd(":=", Ldeclas), Keywd("||", Loror), Keywd("&&", Landand), Keywd("::", Lcons), Keywd("==", Leq), Keywd("!=", Lneq), Keywd("<=", Lleq), Keywd(">=", Lgeq), Keywd("<<", Llsh), Keywd(">>", Lrsh), Keywd("<-", Lcomm), Keywd("++", Linc), Keywd("--", Ldec), Keywd("->", Lmdot), Keywd("=>", Llabs), Keywd("**", Lexp), Keywd("EOF", Leof), }; lexinit() { for(i := 0; i < 256; i++){ map[i] = byte 0; if(i == '_' || i > 16ra0) map[i] |= Munder; if(i >= 'A' && i <= 'Z') map[i] |= Mupper; if(i >= 'a' && i <= 'z') map[i] |= Mlower; if(i >= 'A' && i <= 'F' || i >= 'a' && i <= 'f') map[i] |= Mhex; if(i == 'e' || i == 'E') map[i] |= Mexp; if(i == 'r' || i == 'R') map[i] |= Mradix; if(i == '-' || i == '+') map[i] |= Msign; if(i >= '0' && i <= '9') map[i] |= Mdigit; } for(i = 0; i < len keywords; i++) enter(keywords[i].name, keywords[i].token); } cmap(c: int): byte { if(c<0) return byte 0; if(c<256) return map[c]; return Mlower; } lexstart(in: string) { savec = 0; bstack = 0; nfiles = 0; addfile(ref File(in, 1, 0, -1, nil, 0, -1)); bin = bins[bstack]; lineno = 1; linepos = Linestart; (srcdir, nil) = str->splitr(in, "/"); } getc(): int { if(c := savec){ if(savec >= 0){ linepos++; savec = 0; } return c; } c = bin.getc(); if(c < 0){ savec = -1; return savec; } linepos++; return c; } # # dumps '\u0000' chararcters # ungetc(c: int) { if(c > 0) linepos--; savec = c; } addinclude(s: string) { for(i := 0; i < MaxIncPath; i++){ if(incpath[i] == nil){ incpath[i] = s; return; } } fatal("out of include path space"); } addfile(f: ref File): int { if(lastfile >= nfiles) lastfile = 0; if(nfiles >= len files){ nf := array[nfiles+32] of ref File; nf[0:] = files; files = nf; } files[nfiles] = f; return nfiles++; } # # include a new file # includef(file: ref Sym) { linestack[bstack] = (lineno, linepos); bstack++; if(bstack >= MaxInclude) fatal(lineconv(lineno<<PosBits)+": include file depth too great"); buf := file.name; if(buf[0] != '/') buf = srcdir+buf; b := bufio->open(buf, Bufio->OREAD); for(i := 0; b == nil && i < MaxIncPath && incpath[i] != nil && file.name[0] != '/'; i++){ buf = incpath[i] + "/" + file.name; b = bufio->open(buf, Bufio->OREAD); } bins[bstack] = b; if(bins[bstack] == nil){ yyerror("can't include "+file.name+": "+sprint("%r")); bstack--; }else{ addfile(ref File(buf, lineno+1, -lineno, lineno, nil, 0, -1)); lineno++; linepos = Linestart; } bin = bins[bstack]; } # # we hit eof in the current file # revert to the file which included it. # popinclude() { savec = 0; bstack--; bin = bins[bstack]; (oline, opos) := linestack[bstack]; (f, ln) := fline(oline); lineno++; linepos = opos; addfile(ref File(f.name, lineno, ln-lineno, f.in, f.act, f.actoff, -1)); } # # convert an absolute Line into a file and line within the file # fline(absline: int): (ref File, int) { if(absline < files[lastfile].abs || lastfile+1 < nfiles && absline >= files[lastfile+1].abs){ lastfile = 0; l := 0; r := nfiles - 1; while(l <= r){ m := (r + l) / 2; s := files[m].abs; if(s <= absline){ l = m + 1; lastfile = m; }else r = m - 1; } } return (files[lastfile], absline + files[lastfile].off); } # # read a comment; process #line file renamings # lexcom(): int { i := 0; buf := ""; while((c := getc()) != '\n'){ if(c == Bufio->EOF) return -1; buf[i++] = c; } lineno++; linepos = Linestart; if(len buf < 6 || buf[len buf - 1] != '"' || buf[:5] != "line " && buf[:5] != "line\t") return 0; for(s := 5; buf[s] == ' ' || buf[s] == '\t'; s++) ; if((cmap(buf[s]) & Mdigit) == byte 0) return 0; n := 0; for(; (cmap(c = buf[s]) & Mdigit) != byte 0; s++) n = n * 10 + c - '0'; for(; buf[s] == ' ' || buf[s] == '\t'; s++) ; if(buf[s++] != '"') return 0; buf = buf[s:len buf - 1]; f := files[nfiles - 1]; if(n == f.off+lineno && buf == f.name) return 1; act := f.name; actline := lineno + f.off; if(f.act != nil){ actline += f.actoff; act = f.act; } addfile(ref File(buf, lineno, n-lineno, f.in, act, actline - n, -1)); return 1; } curline(): Line { return (lineno << PosBits) | (linepos & PosMask); } lineconv(line: Line): string { line >>= PosBits; if(line < 0) return "<noline>"; (f, ln) := fline(line); s := ""; if(f.in >= 0){ s = ": " + lineconv(f.in << PosBits); } if(f.act != nil) s = " [ " + f.act + ":" + string(f.actoff+ln) + " ]" + s; return f.name + ":" + string ln + s; } posconv(s: Line): string { if(s < 0) return "nopos"; spos := s & PosMask; s >>= PosBits; (f, ln) := fline(s); return f.name + ":" + string ln + "." + string spos; } srcconv(src: Src): string { s := posconv(src.start); s[len s] = ','; s += posconv(src.stop); return s; } lexid(c: int): int { id := ""; i := 0; for(;;){ if(i < StrSize) id[i++] = c; c = getc(); if(c == Bufio->EOF || (cmap(c) & (Malpha|Mdigit)) == byte 0){ ungetc(c); break; } } sym := enter(id, Lid); t := sym.token; if(t == Lid || t == Ltid) yyctxt.lval.tok.v.idval = sym; return t; } maxfast := array[37] of { 2 => 31, 4 => 15, 8 => 10, 10 => 9, 16 => 7, 32 => 6, * => 0, }; strtoi(t: string, bbase: big): big { # # do the first part in ints # v := 0; bv: big; base := int bbase; n := maxfast[base]; neg := 0; i := 0; if(i < len t && t[i] == '-'){ neg = 1; i++; }else if(i < len t && t[i] == '+') i++; for(; i < len t; i++){ c := t[i]; if(c >= '0' && c <= '9') c -= '0'; else if(c >= 'a' && c <= 'z') c -= 'a' - 10; else c -= 'A' - 10; if(c >= base){ yyerror("digit '"+t[i:i+1]+"' is not radix "+string base); return big -1; } if(i < n) v = v * base + c; else{ if(i == n) bv = big v; bv = bv * bbase + big c; } } if(i <= n) bv = big v; if(neg) return -bv; return bv; } digit(c: int, base: int): int { ck: byte; cc: int; cc = c; ck = cmap(c); if((ck & Mdigit) != byte 0) c -= '0'; else if((ck & Mlower) != byte 0) c = c - 'a' + 10; else if((ck & Mupper) != byte 0) c = c - 'A' + 10; else if((ck & Munder) != byte 0) ; else return -1; if(c >= base){ s := "z"; s[0] = cc; yyerror("digit '" + s + "' not radix " + string base); } return c; } strtodb(t: string, base: int): real { num, dem, rbase: real; neg, eneg, dig, exp, c, d: int; t[len t] = 0; num = 0.0; rbase = real base; neg = 0; dig = 0; exp = 0; eneg = 0; i := 0; c = t[i++]; if(c == '-' || c == '+'){ if(c == '-') neg = 1; c = t[i++]; } while((d = digit(c, base)) >= 0){ num = num*rbase + real d; c = t[i++]; } if(c == '.') c = t[i++]; while((d = digit(c, base)) >= 0){ num = num*rbase + real d; dig++; c = t[i++]; } if(c == 'e' || c == 'E'){ c = t[i++]; if(c == '-' || c == '+'){ if(c == '-'){ dig = -dig; eneg = 1; } c = t[i++]; } while((d = digit(c, base)) >= 0){ exp = exp*base + d; c = t[i++]; } } exp -= dig; if(exp < 0){ exp = -exp; eneg = !eneg; } dem = rpow(rbase, exp); if(eneg) num /= dem; else num *= dem; if(neg) return -num; return num; } # # parse a numeric identifier # format [0-9]+(r[0-9A-Za-z]+)? # or ([0-9]+(\.[0-9]*)?|\.[0-9]+)([eE][+-]?[0-9]+)? # lexnum(c: int): int { Int, Radix, RadixSeen, Frac, ExpSeen, ExpSignSeen, Exp, FracB: con iota; i := 0; buf := ""; buf[i++] = c; state := Int; if(c == '.') state = Frac; radix := ""; done: for(;;){ c = getc(); if(c == Bufio->EOF){ yyerror("end of file in numeric constant"); return Leof; } ck := cmap(c); case state{ Int => if((ck & Mdigit) != byte 0) break; if((ck & Mexp) != byte 0){ state = ExpSeen; break; } if((ck & Mradix) != byte 0){ radix = buf; buf = ""; i = 0; state = RadixSeen; break; } if(c == '.'){ state = Frac; break; } break done; RadixSeen or Radix => if((ck & (Mdigit|Malpha)) != byte 0){ state = Radix; break; } if(c == '.'){ state = FracB; break; } break done; Frac => if((ck & Mdigit) != byte 0) break; if((ck & Mexp) != byte 0) state = ExpSeen; else break done; FracB => if((ck & (Mdigit|Malpha)) != byte 0) break; break done; ExpSeen => if((ck & Msign) != byte 0){ state = ExpSignSeen; break; } if((ck & Mdigit) != byte 0){ state = Exp; break; } break done; ExpSignSeen or Exp => if((ck & Mdigit) != byte 0){ state = Exp; break; } break done; } buf[i++] = c; } ungetc(c); v: big; case state{ * => yyerror("malformed numerical constant '"+radix+buf+"'"); yyctxt.lval.tok.v.ival = big 0; return Lconst; Radix => v = strtoi(radix, big 10); if(v < big 2 || v > big 36){ yyerror("radix '"+radix+"' is not between 2 and 36"); break; } v = strtoi(buf[1:], v); Int => v = strtoi(buf, big 10); Frac or Exp => yyctxt.lval.tok.v.rval = real buf; return Lrconst; FracB => v = strtoi(radix, big 10); if(v < big 2 || v > big 36){ yyerror("radix '"+radix+"' is not between 2 and 36"); break; } yyctxt.lval.tok.v.rval = strtodb(buf[1:], int v); return Lrconst; } yyctxt.lval.tok.v.ival = v; return Lconst; } escchar(): int { c := getc(); if(c == Bufio->EOF) return Bufio->EOF; if(c == 'u'){ v := 0; for(i := 0; i < 4; i++){ c = getc(); ck := cmap(c); if(c == Bufio->EOF || (ck & (Mdigit|Mhex)) == byte 0){ yyerror("malformed \\u escape sequence"); ungetc(c); break; } if((ck & Mdigit) != byte 0) c -= '0'; else if((ck & Mlower) != byte 0) c = c - 'a' + 10; else if((ck & Mupper) != byte 0) c = c - 'A' + 10; v = v * 16 + c; } return v; } if(c < len escmap && (v := escmap[c]) >= 0) return v; s := ""; s[0] = c; yyerror("unrecognized escape \\"+s); return c; } lexstring() { s := ""; i := 0; Loop: for(;;){ case c := getc(){ '\\' => c = escchar(); if(c != Bufio->EOF) s[i++] = c; Bufio->EOF => yyerror("end of file in string constant"); break Loop; '\n' => yyerror("newline in string constant"); lineno++; linepos = Linestart; break Loop; '"' => break Loop; * => s[i++] = c; } } yyctxt.lval.tok.v.idval = enterstring(s); } lexrawstring() { s := ""; i := 0; startlno := lineno; Loop: for(;;){ case c := getc(){ Bufio->EOF => t := lineno; lineno = startlno; yyerror("end of file in raw string constant"); lineno = t; break Loop; '\n' => s[i++] = c; lineno++; linepos = Linestart; '`' => break Loop; * => s[i++] = c; } } yyctxt.lval.tok.v.idval = enterstring(s); } lex(): int { for(;;){ yyctxt.lval.tok.src.start = (lineno << PosBits) | (linepos & PosMask); case c := getc(){ Bufio->EOF => bin.close(); if(bstack == 0) return Leof; popinclude(); '#' => if(lexcom() < 0){ bin.close(); if(bstack == 0) return Leof; popinclude(); } '\n' => lineno++; linepos = Linestart; ' ' or '\t' or '\r' or '\v' => ; '"' => lexstring(); return Lsconst; '`' => lexrawstring(); return Lsconst; '\'' => c = getc(); if(c == '\\') c = escchar(); if(c == Bufio->EOF){ yyerror("end of file in character constant"); return Bufio->EOF; }else yyctxt.lval.tok.v.ival = big c; c = getc(); if(c != '\''){ yyerror("missing closing '"); ungetc(c); } return Lconst; '(' or ')' or '[' or ']' or '{' or '}' or ',' or ';' or '~' => return c; ':' => c = getc(); if(c == ':') return Lcons; if(c == '=') return Ldeclas; ungetc(c); return ':'; '.' => c = getc(); ungetc(c); if(c != Bufio->EOF && (cmap(c) & Mdigit) != byte 0) return lexnum('.'); return '.'; '|' => c = getc(); if(c == '=') return Loreq; if(c == '|') return Loror; ungetc(c); return '|'; '&' => c = getc(); if(c == '=') return Landeq; if(c == '&') return Landand; ungetc(c); return '&'; '^' => c = getc(); if(c == '=') return Lxoreq; ungetc(c); return '^'; '*' => c = getc(); if(c == '=') return Lmuleq; if(c == '*'){ c = getc(); if(c == '=') return Lexpeq; ungetc(c); return Lexp; } ungetc(c); return '*'; '/' => c = getc(); if(c == '=') return Ldiveq; ungetc(c); return '/'; '%' => c = getc(); if(c == '=') return Lmodeq; ungetc(c); return '%'; '=' => c = getc(); if(c == '=') return Leq; if(c == '>') return Llabs; ungetc(c); return '='; '!' => c = getc(); if(c == '=') return Lneq; ungetc(c); return '!'; '>' => c = getc(); if(c == '=') return Lgeq; if(c == '>'){ c = getc(); if(c == '=') return Lrsheq; ungetc(c); return Lrsh; } ungetc(c); return '>'; '<' => c = getc(); if(c == '=') return Lleq; if(c == '-') return Lcomm; if(c == '<'){ c = getc(); if(c == '=') return Llsheq; ungetc(c); return Llsh; } ungetc(c); return '<'; '+' => c = getc(); if(c == '=') return Laddeq; if(c == '+') return Linc; ungetc(c); return '+'; '-' => c = getc(); if(c == '=') return Lsubeq; if(c == '-') return Ldec; if(c == '>') return Lmdot; ungetc(c); return '-'; '0' to '9' => return lexnum(c); * => if((cmap(c) & Malpha) != byte 0) return lexid(c); s := ""; s[0] = c; yyerror("unknown character '"+s+"'"); } } } YYLEX.lex(nil: self ref YYLEX): int { t := lex(); yyctxt.lval.tok.src.stop = (lineno << PosBits) | (linepos & PosMask); lasttok = t; lastyylval = yyctxt.lval; return t; } toksp(t: int): string { case(t){ Lconst => return sprint("%bd", lastyylval.tok.v.ival); Lrconst => return sprint("%f", lastyylval.tok.v.rval); Lsconst => return sprint("\"%s\"", lastyylval.tok.v.idval.name); Ltid or Lid => return lastyylval.tok.v.idval.name; } for(i := 0; i < len keywords; i++) if(t == keywords[i].token) return keywords[i].name; for(i = 0; i < len tokwords; i++) if(t == tokwords[i].token) return tokwords[i].name; if(t < 0 || t > 255) fatal(sprint("bad token %d in toksp()", t)); buf := "Z"; buf[0] = t; return buf; } enterstring(name: string): ref Sym { h := 0; n := len name; for(i := 0; i < n; i++){ c := d := name[i]; c ^= c << 6; h += (c << 11) ^ (c >> 1); h ^= (d << 14) + (d << 7) + (d << 4) + d; } h &= HashSize-1; for(s := strings[h]; s != nil; s = s.next){ sn := s.name; if(len sn == n && sn == name) return s; } s = ref Sym; s.token = -1; s.name = name; s.hash = h; s.next = strings[h]; strings[h] = s; return s; } stringcat(s, t: ref Sym): ref Sym { return enterstring(s.name+t.name); } enter(name: string, token: int): ref Sym { h := 0; n := len name; for(i := 0; i < n; i++){ c := d := name[i]; c ^= c << 6; h += (c << 11) ^ (c >> 1); h ^= (d << 14) + (d << 7) + (d << 4) + d; } h &= HashSize-1; for(s := symbols[h]; s != nil; s = s.next){ sn := s.name; if(len sn == n && sn == name) return s; } if(token == 0) token = Lid; s = ref Sym; s.token = token; s.name = name; s.hash = h; s.next = symbols[h]; symbols[h] = s; return s; } stringpr(sym: ref Sym): string { s := sym.name; n := len s; if(n > 10) n = 10; sb := "\""; for(i := 0; i < n; i++){ case c := s[i]{ '\\' or '"' or '\n' or '\r' or '\t' or '\b' or '\a' or '\v' or '\u0000' => sb[len sb] = '\\'; sb[len sb] = unescmap[c]; * => sb[len sb] = c; } } if(n != len s) sb += "..."; sb[len sb] = '"'; return sb; } warn(line: Line, msg: string) { if(errors || !dowarn) return; fprint(stderr, "%s: warning: %s\n", lineconv(line), msg); } nwarn(n: ref Node, msg: string) { if(errors || !dowarn) return; fprint(stderr, "%s: warning: %s\n", lineconv(n.src.start), msg); } error(line: Line, msg: string) { errors++; if(errors > maxerr) return; fprint(stderr, "%s: %s\n", lineconv(line), msg); if(errors == maxerr) fprint(stderr, "too many errors, stopping\n"); } nerror(n: ref Node, msg: string) { errors++; if(errors > maxerr) return; fprint(stderr, "%s: %s\n", lineconv(n.src.start), msg); if(errors == maxerr) fprint(stderr, "too many errors, stopping\n"); } YYLEX.error(nil: self ref YYLEX, msg: string) { errors++; if(errors > maxerr) return; if(lasttok != 0) fprint(stderr, "%s: near ` %s ` : %s\n", lineconv(lineno<<PosBits), toksp(lasttok), msg); else fprint(stderr, "%s: %s\n", lineconv(lineno<<PosBits), msg); if(errors == maxerr) fprint(stderr, "too many errors, stopping\n"); } yyerror(msg: string) { yyctxt.error(msg); } fatal(msg: string) { if(errors == 0 || fabort) fprint(stderr, "fatal limbo compiler error: %s\n", msg); if(bout != nil) sys->remove(outfile); if(fabort){ n: ref Node; if(n.ty == nil); # abort } raise "fail:error"; } hex(v, n: int): string { return sprint("%.*ux", n, v); } bhex(v: big, n: int): string { return sprint("%.*bux", n, v); }