ref: eb1be5b4df533c4e5100296fb042e274da435b5b
dir: /sys/src/ape/cmd/pdksh/syn.c/
/* * shell parser (C version) */ #include "sh.h" #include "c_test.h" struct nesting_state { int start_token; /* token than began nesting (eg, FOR) */ int start_line; /* line nesting began on */ }; static void yyparse ARGS((void)); static struct op *pipeline ARGS((int cf)); static struct op *andor ARGS((void)); static struct op *c_list ARGS((int multi)); static struct ioword *synio ARGS((int cf)); static void musthave ARGS((int c, int cf)); static struct op *nested ARGS((int type, int smark, int emark)); static struct op *get_command ARGS((int cf)); static struct op *dogroup ARGS((void)); static struct op *thenpart ARGS((void)); static struct op *elsepart ARGS((void)); static struct op *caselist ARGS((void)); static struct op *casepart ARGS((int endtok)); static struct op *function_body ARGS((char *name, int ksh_func)); static char ** wordlist ARGS((void)); static struct op *block ARGS((int type, struct op *t1, struct op *t2, char **wp)); static struct op *newtp ARGS((int type)); static void syntaxerr ARGS((const char *what)) GCC_FUNC_ATTR(noreturn); static void nesting_push ARGS((struct nesting_state *save, int tok)); static void nesting_pop ARGS((struct nesting_state *saved)); static int assign_command ARGS((char *s)); static int inalias ARGS((struct source *s)); #ifdef KSH static int dbtestp_isa ARGS((Test_env *te, Test_meta meta)); static const char *dbtestp_getopnd ARGS((Test_env *te, Test_op op, int do_eval)); static int dbtestp_eval ARGS((Test_env *te, Test_op op, const char *opnd1, const char *opnd2, int do_eval)); static void dbtestp_error ARGS((Test_env *te, int offset, const char *msg)); #endif /* KSH */ static struct op *outtree; /* yyparse output */ static struct nesting_state nesting; /* \n changed to ; */ static int reject; /* token(cf) gets symbol again */ static int symbol; /* yylex value */ #define REJECT (reject = 1) #define ACCEPT (reject = 0) #define token(cf) \ ((reject) ? (ACCEPT, symbol) : (symbol = yylex(cf))) #define tpeek(cf) \ ((reject) ? (symbol) : (REJECT, symbol = yylex(cf))) static void yyparse() { int c; ACCEPT; outtree = c_list(source->type == SSTRING); c = tpeek(0); if (c == 0 && !outtree) outtree = newtp(TEOF); else if (c != '\n' && c != 0) syntaxerr((char *) 0); } static struct op * pipeline(cf) int cf; { register struct op *t, *p, *tl = NULL; t = get_command(cf); if (t != NULL) { while (token(0) == '|') { if ((p = get_command(CONTIN)) == NULL) syntaxerr((char *) 0); if (tl == NULL) t = tl = block(TPIPE, t, p, NOWORDS); else tl = tl->right = block(TPIPE, tl->right, p, NOWORDS); } REJECT; } return (t); } static struct op * andor() { register struct op *t, *p; register int c; t = pipeline(0); if (t != NULL) { while ((c = token(0)) == LOGAND || c == LOGOR) { if ((p = pipeline(CONTIN)) == NULL) syntaxerr((char *) 0); t = block(c == LOGAND? TAND: TOR, t, p, NOWORDS); } REJECT; } return (t); } static struct op * c_list(multi) int multi; { register struct op *t = NULL, *p, *tl = NULL; register int c; int have_sep; while (1) { p = andor(); /* Token has always been read/rejected at this point, so * we don't worry about what flags to pass token() */ c = token(0); have_sep = 1; if (c == '\n' && (multi || inalias(source))) { if (!p) /* ignore blank lines */ continue; } else if (!p) break; else if (c == '&' || c == COPROC) p = block(c == '&' ? TASYNC : TCOPROC, p, NOBLOCK, NOWORDS); else if (c != ';') have_sep = 0; if (!t) t = p; else if (!tl) t = tl = block(TLIST, t, p, NOWORDS); else tl = tl->right = block(TLIST, tl->right, p, NOWORDS); if (!have_sep) break; } REJECT; return t; } static struct ioword * synio(cf) int cf; { register struct ioword *iop; int ishere; if (tpeek(cf) != REDIR) return NULL; ACCEPT; iop = yylval.iop; ishere = (iop->flag&IOTYPE) == IOHERE; musthave(LWORD, ishere ? HEREDELIM : 0); if (ishere) { iop->delim = yylval.cp; if (*ident != 0) /* unquoted */ iop->flag |= IOEVAL; if (herep >= &heres[HERES]) yyerror("too many <<'s\n"); *herep++ = iop; } else iop->name = yylval.cp; return iop; } static void musthave(c, cf) int c, cf; { if ((token(cf)) != c) syntaxerr((char *) 0); } static struct op * nested(type, smark, emark) int type, smark, emark; { register struct op *t; struct nesting_state old_nesting; nesting_push(&old_nesting, smark); t = c_list(TRUE); musthave(emark, KEYWORD|ALIAS); nesting_pop(&old_nesting); return (block(type, t, NOBLOCK, NOWORDS)); } static struct op * get_command(cf) int cf; { register struct op *t; register int c, iopn = 0, syniocf; struct ioword *iop, **iops; XPtrV args, vars; struct nesting_state old_nesting; iops = (struct ioword **) alloc(sizeofN(struct ioword *, NUFILE+1), ATEMP); XPinit(args, 16); XPinit(vars, 16); syniocf = KEYWORD|ALIAS; switch (c = token(cf|KEYWORD|ALIAS|VARASN)) { default: REJECT; afree((void*) iops, ATEMP); XPfree(args); XPfree(vars); return NULL; /* empty line */ case LWORD: case REDIR: REJECT; syniocf &= ~(KEYWORD|ALIAS); t = newtp(TCOM); t->lineno = source->line; while (1) { cf = (t->u.evalflags ? ARRAYVAR : 0) | (XPsize(args) == 0 ? ALIAS|VARASN : CMDWORD); switch (tpeek(cf)) { case REDIR: if (iopn >= NUFILE) yyerror("too many redirections\n"); iops[iopn++] = synio(cf); break; case LWORD: ACCEPT; /* the iopn == 0 and XPsize(vars) == 0 are * dubious but at&t ksh acts this way */ if (iopn == 0 && XPsize(vars) == 0 && XPsize(args) == 0 && assign_command(ident)) t->u.evalflags = DOVACHECK; if ((XPsize(args) == 0 || Flag(FKEYWORD)) && is_wdvarassign(yylval.cp)) XPput(vars, yylval.cp); else XPput(args, yylval.cp); break; case '(': /* Check for "> foo (echo hi)", which at&t ksh * allows (not POSIX, but not disallowed) */ afree(t, ATEMP); if (XPsize(args) == 0 && XPsize(vars) == 0) { ACCEPT; goto Subshell; } /* Must be a function */ if (iopn != 0 || XPsize(args) != 1 || XPsize(vars) != 0) syntaxerr((char *) 0); ACCEPT; /*(*/ musthave(')', 0); t = function_body(XPptrv(args)[0], FALSE); goto Leave; default: goto Leave; } } Leave: break; Subshell: case '(': t = nested(TPAREN, '(', ')'); break; case '{': /*}*/ t = nested(TBRACE, '{', '}'); break; #ifdef KSH case MDPAREN: { static const char let_cmd[] = { CHAR, 'l', CHAR, 'e', CHAR, 't', EOS }; /* Leave KEYWORD in syniocf (allow if (( 1 )) then ...) */ t = newtp(TCOM); t->lineno = source->line; ACCEPT; XPput(args, wdcopy(let_cmd, ATEMP)); musthave(LWORD,LETEXPR); XPput(args, yylval.cp); break; } #endif /* KSH */ #ifdef KSH case DBRACKET: /* [[ .. ]] */ /* Leave KEYWORD in syniocf (allow if [[ -n 1 ]] then ...) */ t = newtp(TDBRACKET); ACCEPT; { Test_env te; te.flags = TEF_DBRACKET; te.pos.av = &args; te.isa = dbtestp_isa; te.getopnd = dbtestp_getopnd; te.eval = dbtestp_eval; te.error = dbtestp_error; test_parse(&te); } break; #endif /* KSH */ case FOR: case SELECT: t = newtp((c == FOR) ? TFOR : TSELECT); musthave(LWORD, ARRAYVAR); if (!is_wdvarname(yylval.cp, TRUE)) yyerror("%s: bad identifier\n", c == FOR ? "for" : "select"); t->str = str_save(ident, ATEMP); nesting_push(&old_nesting, c); t->vars = wordlist(); t->left = dogroup(); nesting_pop(&old_nesting); break; case WHILE: case UNTIL: nesting_push(&old_nesting, c); t = newtp((c == WHILE) ? TWHILE : TUNTIL); t->left = c_list(TRUE); t->right = dogroup(); nesting_pop(&old_nesting); break; case CASE: t = newtp(TCASE); musthave(LWORD, 0); t->str = yylval.cp; nesting_push(&old_nesting, c); t->left = caselist(); nesting_pop(&old_nesting); break; case IF: nesting_push(&old_nesting, c); t = newtp(TIF); t->left = c_list(TRUE); t->right = thenpart(); musthave(FI, KEYWORD|ALIAS); nesting_pop(&old_nesting); break; case BANG: syniocf &= ~(KEYWORD|ALIAS); t = pipeline(0); if (t == (struct op *) 0) syntaxerr((char *) 0); t = block(TBANG, NOBLOCK, t, NOWORDS); break; case TIME: syniocf &= ~(KEYWORD|ALIAS); t = pipeline(0); t = block(TTIME, t, NOBLOCK, NOWORDS); break; case FUNCTION: musthave(LWORD, 0); t = function_body(yylval.cp, TRUE); break; } while ((iop = synio(syniocf)) != NULL) { if (iopn >= NUFILE) yyerror("too many redirections\n"); iops[iopn++] = iop; } if (iopn == 0) { afree((void*) iops, ATEMP); t->ioact = NULL; } else { iops[iopn++] = NULL; iops = (struct ioword **) aresize((void*) iops, sizeofN(struct ioword *, iopn), ATEMP); t->ioact = iops; } if (t->type == TCOM || t->type == TDBRACKET) { XPput(args, NULL); t->args = (char **) XPclose(args); XPput(vars, NULL); t->vars = (char **) XPclose(vars); } else { XPfree(args); XPfree(vars); } return t; } static struct op * dogroup() { register int c; register struct op *list; c = token(CONTIN|KEYWORD|ALIAS); /* A {...} can be used instead of do...done for for/select loops * but not for while/until loops - we don't need to check if it * is a while loop because it would have been parsed as part of * the conditional command list... */ if (c == DO) c = DONE; else if (c == '{') c = '}'; else syntaxerr((char *) 0); list = c_list(TRUE); musthave(c, KEYWORD|ALIAS); return list; } static struct op * thenpart() { register struct op *t; musthave(THEN, KEYWORD|ALIAS); t = newtp(0); t->left = c_list(TRUE); if (t->left == NULL) syntaxerr((char *) 0); t->right = elsepart(); return (t); } static struct op * elsepart() { register struct op *t; switch (token(KEYWORD|ALIAS|VARASN)) { case ELSE: if ((t = c_list(TRUE)) == NULL) syntaxerr((char *) 0); return (t); case ELIF: t = newtp(TELIF); t->left = c_list(TRUE); t->right = thenpart(); return (t); default: REJECT; } return NULL; } static struct op * caselist() { register struct op *t, *tl; int c; c = token(CONTIN|KEYWORD|ALIAS); /* A {...} can be used instead of in...esac for case statements */ if (c == IN) c = ESAC; else if (c == '{') c = '}'; else syntaxerr((char *) 0); t = tl = NULL; while ((tpeek(CONTIN|KEYWORD|ESACONLY)) != c) { /* no ALIAS here */ struct op *tc = casepart(c); if (tl == NULL) t = tl = tc, tl->right = NULL; else tl->right = tc, tl = tc; } musthave(c, KEYWORD|ALIAS); return (t); } static struct op * casepart(endtok) int endtok; { register struct op *t; register int c; XPtrV ptns; XPinit(ptns, 16); t = newtp(TPAT); c = token(CONTIN|KEYWORD); /* no ALIAS here */ if (c != '(') REJECT; do { musthave(LWORD, 0); XPput(ptns, yylval.cp); } while ((c = token(0)) == '|'); REJECT; XPput(ptns, NULL); t->vars = (char **) XPclose(ptns); musthave(')', 0); t->left = c_list(TRUE); /* Note: Posix requires the ;; */ if ((tpeek(CONTIN|KEYWORD|ALIAS)) != endtok) musthave(BREAK, CONTIN|KEYWORD|ALIAS); return (t); } static struct op * function_body(name, ksh_func) char *name; int ksh_func; /* function foo { ... } vs foo() { .. } */ { char *sname, *p; struct op *t; int old_func_parse; sname = wdstrip(name); /* Check for valid characters in name. posix and ksh93 say only * allow [a-zA-Z_0-9] but this allows more as old pdksh's have * allowed more (the following were never allowed: * nul space nl tab $ ' " \ ` ( ) & | ; = < > * C_QUOTE covers all but = and adds # [ ? *) */ for (p = sname; *p; p++) if (ctype(*p, C_QUOTE) || *p == '=') yyerror("%s: invalid function name\n", sname); t = newtp(TFUNCT); t->str = sname; t->u.ksh_func = ksh_func; t->lineno = source->line; /* Note that POSIX allows only compound statements after foo(), sh and * at&t ksh allow any command, go with the later since it shouldn't * break anything. However, for function foo, at&t ksh only accepts * an open-brace. */ if (ksh_func) { musthave('{', CONTIN|KEYWORD|ALIAS); /* } */ REJECT; } old_func_parse = e->flags & EF_FUNC_PARSE; e->flags |= EF_FUNC_PARSE; if ((t->left = get_command(CONTIN)) == (struct op *) 0) { /* * Probably something like foo() followed by eof or ;. * This is accepted by sh and ksh88. * To make "typset -f foo" work reliably (so its output can * be used as input), we pretend there is a colon here. */ t->left = newtp(TCOM); t->left->args = (char **) alloc(sizeof(char *) * 2, ATEMP); t->left->args[0] = alloc(sizeof(char) * 3, ATEMP); t->left->args[0][0] = CHAR; t->left->args[0][1] = ':'; t->left->args[0][2] = EOS; t->left->args[1] = (char *) 0; t->left->vars = (char **) alloc(sizeof(char *), ATEMP); t->left->vars[0] = (char *) 0; t->left->lineno = 1; } if (!old_func_parse) e->flags &= ~EF_FUNC_PARSE; return t; } static char ** wordlist() { register int c; XPtrV args; XPinit(args, 16); /* Posix does not do alias expansion here... */ if ((c = token(CONTIN|KEYWORD|ALIAS)) != IN) { if (c != ';') /* non-POSIX, but at&t ksh accepts a ; here */ REJECT; return NULL; } while ((c = token(0)) == LWORD) XPput(args, yylval.cp); if (c != '\n' && c != ';') syntaxerr((char *) 0); if (XPsize(args) == 0) { XPfree(args); return NULL; } else { XPput(args, NULL); return (char **) XPclose(args); } } /* * supporting functions */ static struct op * block(type, t1, t2, wp) int type; struct op *t1, *t2; char **wp; { register struct op *t; t = newtp(type); t->left = t1; t->right = t2; t->vars = wp; return (t); } const struct tokeninfo { const char *name; short val; short reserved; } tokentab[] = { /* Reserved words */ { "if", IF, TRUE }, { "then", THEN, TRUE }, { "else", ELSE, TRUE }, { "elif", ELIF, TRUE }, { "fi", FI, TRUE }, { "case", CASE, TRUE }, { "esac", ESAC, TRUE }, { "for", FOR, TRUE }, #ifdef KSH { "select", SELECT, TRUE }, #endif /* KSH */ { "while", WHILE, TRUE }, { "until", UNTIL, TRUE }, { "do", DO, TRUE }, { "done", DONE, TRUE }, { "in", IN, TRUE }, { "function", FUNCTION, TRUE }, { "time", TIME, TRUE }, { "{", '{', TRUE }, { "}", '}', TRUE }, { "!", BANG, TRUE }, #ifdef KSH { "[[", DBRACKET, TRUE }, #endif /* KSH */ /* Lexical tokens (0[EOF], LWORD and REDIR handled specially) */ { "&&", LOGAND, FALSE }, { "||", LOGOR, FALSE }, { ";;", BREAK, FALSE }, #ifdef KSH { "((", MDPAREN, FALSE }, { "|&", COPROC, FALSE }, #endif /* KSH */ /* and some special cases... */ { "newline", '\n', FALSE }, { 0 } }; void initkeywords() { register struct tokeninfo const *tt; register struct tbl *p; tinit(&keywords, APERM, 32); /* must be 2^n (currently 20 keywords) */ for (tt = tokentab; tt->name; tt++) { if (tt->reserved) { p = tenter(&keywords, tt->name, hash(tt->name)); p->flag |= DEFINED|ISSET; p->type = CKEYWD; p->val.i = tt->val; } } } static void syntaxerr(what) const char *what; { char redir[6]; /* 2<<- is the longest redirection, I think */ const char *s; struct tokeninfo const *tt; int c; if (!what) what = "unexpected"; REJECT; c = token(0); Again: switch (c) { case 0: if (nesting.start_token) { c = nesting.start_token; source->errline = nesting.start_line; what = "unmatched"; goto Again; } /* don't quote the EOF */ yyerror("syntax error: unexpected EOF\n"); /*NOTREACHED*/ case LWORD: s = snptreef((char *) 0, 32, "%S", yylval.cp); break; case REDIR: s = snptreef(redir, sizeof(redir), "%R", yylval.iop); break; default: for (tt = tokentab; tt->name; tt++) if (tt->val == c) break; if (tt->name) s = tt->name; else { if (c > 0 && c < 256) { redir[0] = c; redir[1] = '\0'; } else shf_snprintf(redir, sizeof(redir), "?%d", c); s = redir; } } yyerror("syntax error: `%s' %s\n", s, what); } static void nesting_push(save, tok) struct nesting_state *save; int tok; { *save = nesting; nesting.start_token = tok; nesting.start_line = source->line; } static void nesting_pop(saved) struct nesting_state *saved; { nesting = *saved; } static struct op * newtp(type) int type; { register struct op *t; t = (struct op *) alloc(sizeof(*t), ATEMP); t->type = type; t->u.evalflags = 0; t->args = t->vars = NULL; t->ioact = NULL; t->left = t->right = NULL; t->str = NULL; return (t); } struct op * compile(s) Source *s; { nesting.start_token = 0; nesting.start_line = 0; herep = heres; source = s; yyparse(); return outtree; } /* This kludge exists to take care of sh/at&t ksh oddity in which * the arguments of alias/export/readonly/typeset have no field * splitting, file globbing, or (normal) tilde expansion done. * at&t ksh seems to do something similar to this since * $ touch a=a; typeset a=[ab]; echo "$a" * a=[ab] * $ x=typeset; $x a=[ab]; echo "$a" * a=a * $ */ static int assign_command(s) char *s; { char c = *s; if (Flag(FPOSIX) || !*s) return 0; return (c == 'a' && strcmp(s, "alias") == 0) || (c == 'e' && strcmp(s, "export") == 0) || (c == 'r' && strcmp(s, "readonly") == 0) || (c == 't' && strcmp(s, "typeset") == 0); } /* Check if we are in the middle of reading an alias */ static int inalias(s) struct source *s; { for (; s && s->type == SALIAS; s = s->next) if (!(s->flags & SF_ALIASEND)) return 1; return 0; } #ifdef KSH /* Order important - indexed by Test_meta values * Note that ||, &&, ( and ) can't appear in as unquoted strings * in normal shell input, so these can be interpreted unambiguously * in the evaluation pass. */ static const char dbtest_or[] = { CHAR, '|', CHAR, '|', EOS }; static const char dbtest_and[] = { CHAR, '&', CHAR, '&', EOS }; static const char dbtest_not[] = { CHAR, '!', EOS }; static const char dbtest_oparen[] = { CHAR, '(', EOS }; static const char dbtest_cparen[] = { CHAR, ')', EOS }; const char *const dbtest_tokens[] = { dbtest_or, dbtest_and, dbtest_not, dbtest_oparen, dbtest_cparen }; const char db_close[] = { CHAR, ']', CHAR, ']', EOS }; const char db_lthan[] = { CHAR, '<', EOS }; const char db_gthan[] = { CHAR, '>', EOS }; /* Test if the current token is a whatever. Accepts the current token if * it is. Returns 0 if it is not, non-zero if it is (in the case of * TM_UNOP and TM_BINOP, the returned value is a Test_op). */ static int dbtestp_isa(te, meta) Test_env *te; Test_meta meta; { int c = tpeek(ARRAYVAR | (meta == TM_BINOP ? 0 : CONTIN)); int uqword = 0; char *save = (char *) 0; int ret = 0; /* unquoted word? */ uqword = c == LWORD && *ident; if (meta == TM_OR) ret = c == LOGOR; else if (meta == TM_AND) ret = c == LOGAND; else if (meta == TM_NOT) ret = uqword && strcmp(yylval.cp, dbtest_tokens[(int) TM_NOT]) == 0; else if (meta == TM_OPAREN) ret = c == '(' /*)*/; else if (meta == TM_CPAREN) ret = c == /*(*/ ')'; else if (meta == TM_UNOP || meta == TM_BINOP) { if (meta == TM_BINOP && c == REDIR && (yylval.iop->flag == IOREAD || yylval.iop->flag == IOWRITE)) { ret = 1; save = wdcopy(yylval.iop->flag == IOREAD ? db_lthan : db_gthan, ATEMP); } else if (uqword && (ret = (int) test_isop(te, meta, ident))) save = yylval.cp; } else /* meta == TM_END */ ret = uqword && strcmp(yylval.cp, db_close) == 0; if (ret) { ACCEPT; if (meta != TM_END) { if (!save) save = wdcopy(dbtest_tokens[(int) meta], ATEMP); XPput(*te->pos.av, save); } } return ret; } static const char * dbtestp_getopnd(te, op, do_eval) Test_env *te; Test_op op; int do_eval; { int c = tpeek(ARRAYVAR); if (c != LWORD) return (const char *) 0; ACCEPT; XPput(*te->pos.av, yylval.cp); return null; } static int dbtestp_eval(te, op, opnd1, opnd2, do_eval) Test_env *te; Test_op op; const char *opnd1; const char *opnd2; int do_eval; { return 1; } static void dbtestp_error(te, offset, msg) Test_env *te; int offset; const char *msg; { te->flags |= TEF_ERROR; if (offset < 0) { REJECT; /* Kludgy to say the least... */ symbol = LWORD; yylval.cp = *(XPptrv(*te->pos.av) + XPsize(*te->pos.av) + offset); } syntaxerr(msg); } #endif /* KSH */