From: lum <lum@openbsd.org>
Date: Sat, 20 Mar 2021 19:39:30 +0000 (+0000)
Subject: Looking at loading all expressions initially, working towards multi
X-Git-Url: http://artulab.com/gitweb/?a=commitdiff_plain;h=bbed9a29562e65f2d4b3ceb3968f51f8e8c42ace;p=openbsd

Looking at loading all expressions initially, working towards multi
line. Next to look at "values" (quotes around values).

Current regress tests pass.
---

diff --git a/usr.bin/mg/interpreter.c b/usr.bin/mg/interpreter.c
index 1100237d836..3fb64508bea 100644
--- a/usr.bin/mg/interpreter.c
+++ b/usr.bin/mg/interpreter.c
@@ -1,4 +1,4 @@
-/*      $OpenBSD: interpreter.c,v 1.9 2021/03/08 20:01:43 lum Exp $	*/
+/*      $OpenBSD: interpreter.c,v 1.10 2021/03/20 19:39:30 lum Exp $	*/
 /*
  * This file is in the public domain.
  *
@@ -35,9 +35,8 @@
  * 1. multiline parsing - currently only single lines supported.
  * 2. parsing for '(' and ')' throughout whole string and evaluate correctly.
  * 3. conditional execution.
- * 4. define single value variables (define i 0)
- * 5. deal with quotes around a string: "x x"
- * 6. oh so many things....
+ * 4. deal with quotes around a string: "x x"
+ * 5. oh so many things....
  * [...]
  * n. implement user definable functions.
  */
@@ -60,6 +59,18 @@ static int	 multiarg(char *);
 static int	 isvar(char **, char **, int);
 static int	 foundvar(char *);
 static int	 doregex(char *, char *);
+static int	 parseexp(char *);
+static void	 clearexp(void);
+
+struct expentry {
+	SLIST_ENTRY(expentry) eentry;
+	char	*exp;		/* The string found between paraenthesis. */
+	int	 par1;		/* Parenthesis at start of string (=1	  */
+	int	 par2;		/* Parenthesis at end of string   )=2     */
+	int	 expctr;	/* An incremental counter:+1 for each exp */
+	int	 blkid;		/* Which block are we in?		  */
+};
+SLIST_HEAD(elisthead, expentry) exphead = SLIST_HEAD_INITIALIZER(exphead);
 
 /*
  * Structure for variables during buffer evaluation.
@@ -72,6 +83,163 @@ struct varentry {
 };
 SLIST_HEAD(vlisthead, varentry) varhead = SLIST_HEAD_INITIALIZER(varhead);
 
+/*
+ * Line has a '(' as the first non-white char.
+ * Do some very basic parsing of line.
+ * Multi-line not supported at the moment, To do.
+ */
+int
+foundparen(char *funstr)
+{
+	struct expentry *e1 = NULL;
+	char		*p, *valp, *endp = NULL, *regs;
+	char		 expbuf[BUFSIZE], tmpbuf[BUFSIZE];
+	int     	 ret, pctr, fndstart, expctr, blkid, fndchr, fndend;
+
+	pctr = fndstart = expctr = fndchr = fndend = 0;
+	blkid = 1;
+	/*
+	 * Check for blocks of code with opening and closing ().
+	 * One block = (cmd p a r a m)
+	 * Two blocks = (cmd p a r a m s)(hola)
+	 * Two blocks = (cmd p a r (list a m s))(hola)
+	 * Only single line at moment, but more for multiline.
+	 */
+	p = funstr;
+
+	/*
+	 * Currently can't do () or (( at the moment,
+	 * just drop out - stops a segv. TODO.
+	 */
+	regs = "[(]+[\t ]*[)]+";
+        if (doregex(regs, funstr))
+		return(dobeep_msg("Empty lists not supported at moment"));
+	regs = "[(]+[\t ]*[(]+";
+        if (doregex(regs, funstr))
+		return(dobeep_msg("Multiple left parantheses found"));
+	/*
+	 * load expressions into a list called 'expentry', to be processd
+	 * when all are obtained.
+	 * Not really live code at the moment. Just part of the process of
+	 * working out what needs to be done.
+	 */
+	while (*p != '\0') {
+		if (*p == '(') {
+			if (fndstart == 1) {
+				if (endp == NULL)
+					*p = '\0';
+				else
+					*endp = '\0';
+				e1->par2 = 1;
+	                        if ((e1->exp = strndup(valp, BUFSIZE)) == NULL)
+        	                        return(dobeep_msg("strndup error"));
+			}
+			if ((e1 = malloc(sizeof(struct expentry))) == NULL)
+                               	return (dobeep_msg("malloc Error"));
+                       	SLIST_INSERT_HEAD(&exphead, e1, eentry);
+			e1->exp = NULL;
+                       	e1->expctr = ++expctr;
+			e1->blkid = blkid;
+                       	e1->par1 = 1; 
+			fndstart = 1;
+			fndend = 0;
+			fndchr = 0;
+			endp = NULL;
+			pctr++;
+		} else if (*p == ')') {
+			if (endp == NULL)
+				*p = '\0';
+			else
+				*endp = '\0';
+			if ((e1->exp = strndup(valp, BUFSIZE)) == NULL)
+				return(dobeep_msg("strndup error"));
+			fndstart = 0;
+			pctr--;
+		} else if (*p != ' ' && *p != '\t') {
+			if (fndchr == 0) {
+				valp = p;
+				fndchr = 1;
+			}
+			fndend = 0;
+			endp = NULL;
+		} else if (fndend == 0 && (*p == ' ' || *p == '\t')) {
+			*p = ' ';
+			fndend = 1;
+			endp = p;
+		} else if (*p == '\t') /* need to check not between "" */
+			*p = ' ';
+		if (pctr == 0)
+			blkid++;
+		p++;
+	}
+	expbuf[0] = tmpbuf[0] = '\0';
+
+	/*
+	 * Join expressions together for the moment, to progess.
+	 * This needs to be totally redone and
+	 * iterate in-to-out, evaluating as we go. Eventually.
+	 */
+	SLIST_FOREACH(e1, &exphead, eentry) {
+		if (strlcpy(tmpbuf, expbuf, sizeof(tmpbuf)) >= sizeof(tmpbuf))
+			return (dobeep_msg("strlcpy error"));
+		expbuf[0] = '\0';
+		if (strlcpy(expbuf, e1->exp, sizeof(expbuf)) >= sizeof(expbuf))
+                	return (dobeep_msg("strlcat error"));
+		if (*tmpbuf != '\0')
+			if (strlcat(expbuf, " ", sizeof(expbuf)) >=
+			    sizeof(expbuf))
+				return (dobeep_msg("strlcat error"));
+		if (strlcat(expbuf, tmpbuf, sizeof(expbuf)) >= sizeof(expbuf))
+			return (dobeep_msg("strlcat error"));
+#ifdef MGLOG
+		mglog_misc("exp|%s|\n", e1->exp);
+#endif
+	}
+	if (pctr != 0) {
+		clearexp();
+		return(dobeep_msg("Opening and closing parentheses error"));
+	}
+	
+	ret = parseexp(expbuf);
+	clearexp();
+
+	return (ret);
+}
+
+/*
+ * At the moment, only paring list defines. Much more to do.
+ */
+static int
+parseexp(char *funstr)
+{
+	char    *regs;
+
+        /* Does the line have a list 'define' like: */
+        /* (define alist(list 1 2 3 4)) */
+        regs = "^define[ ]+.*[ ]+list[ ]+.*[ ]*";
+        if (doregex(regs, funstr))
+                return(foundvar(funstr));
+
+        /* Does the line have a incorrect variable 'define' like: */
+        /* (define i y z) */
+        regs = "^define[ ]+.*[ ]+.*[ ]+.*$";
+        if (doregex(regs, funstr))
+                return(dobeep_msg("Invalid use of define."));
+
+        /* Does the line have a single variable 'define' like: */
+        /* (define i 0) */
+        regs = "^define[ ]+.*[ ]+.*$";
+        if (doregex(regs, funstr))
+                return(foundvar(funstr));
+
+        /* Does the line have an unrecognised 'define' */
+        regs = "^define[\t ]+";
+        if (doregex(regs, funstr))
+                return(dobeep_msg("Invalid use of define"));
+
+	return(multiarg(funstr));
+}
+
 /*
  * Pass a list of arguments to a function.
  */
@@ -79,42 +247,17 @@ static int
 multiarg(char *funstr)
 {
 	PF	 funcp;
-	char	 excbuf[BUFSIZE], argbuf[BUFSIZE], *contbuf, tmpbuf[BUFSIZE];
-	char	*cmdp, *argp, *fendp, *endp, *p, *t, *s = " ";
-	int	 singlecmd = 0, spc, numparams, numspc;
-	int	 inlist, foundlst = 0, eolst, rpar, sizof, fin;
+	char	 excbuf[BUFSIZE], argbuf[BUFSIZE];
+	char	 contbuf[BUFSIZE], varbuf[BUFSIZE];
+	char	*cmdp = NULL, *argp, *fendp = NULL, *endp, *p, *v, *s = " ";
+	int	 spc, numparams, numspc;
+	int	 inlist, sizof, fin;
 	
-	contbuf = NULL;
-	endp = strrchr(funstr, ')');
-	if (endp == NULL) {
-		ewprintf("No closing parenthesis found");
-		return(FALSE);
-	}
-	p = endp + 1;
-	if (*p != '\0')
-		*p = '\0';
-	/* we now know that string starts with '(' and ends with ')' */
-        if (doregex("^[(][\t ]*[)]$", funstr))
-                return(dobeep_msg("No command found"));
-
-        if (doregex("^[(][\t ]*[A-Za-z-]+[\t ]*[)]$", funstr))
-		singlecmd = 1;
-
-	p = funstr + 1;		/* move past first '(' char.	*/
-	cmdp = skipwhite(p);	/* find first char of command.	*/
-
-	if (singlecmd) {
-		/* remove ')', then check for spaces at the end */
-		cmdp[strlen(cmdp) - 1] = '\0'; 
-		if ((fendp = strchr(cmdp, ' ')) != NULL)
-			*fendp = '\0';
-		else if ((fendp = strchr(cmdp, '\t')) != NULL)
-			*fendp = '\0';
-		return(excline(cmdp));
-	}
-	if ((fendp = strchr(cmdp, ' ')) == NULL) 
-		fendp = strchr(cmdp, '\t');
+        if (doregex("^[A-Za-z-]+$", funstr))
+		return(excline(funstr));
 
+	cmdp = funstr;
+	fendp = strchr(cmdp, ' ');
 	*fendp = '\0';
 	/*
 	 * If no extant mg command found, just return.
@@ -127,101 +270,79 @@ multiarg(char *funstr)
 		return (dobeep_msgs("Command takes no arguments: ", cmdp));
 
 	/* now find the first argument */
-	if (fendp)
-		p = fendp + 1;
-	else
-		p = "";
+	p = fendp + 1;
 	p = skipwhite(p);
+
 	if (strlcpy(argbuf, p, sizeof(argbuf)) >= sizeof(argbuf))
 		return (dobeep_msg("strlcpy error"));
 	argp = argbuf;
 	numspc = spc = 1; /* initially fake a space so we find first argument */
-	inlist = eolst = fin = rpar = 0;
+	inlist = fin = 0;
 
-	for (p = argp; fin == 0; p++) {
-#ifdef  MGLOG
-		mglog_execbuf("", excbuf, argbuf, argp, eolst, inlist, cmdp,
-		    p, contbuf);
-#endif
-		if (foundlst) {
-			foundlst = 0;
-			p--;	/* otherwise 1st arg is missed from list. */
-		}
-		if (*p == ')') {
-			rpar = 1;
-			*p = '\0';
+	for (p = argbuf; *p != '\0'; p++) {
+		if (*(p + 1) == '\0')
+			fin = 1;
+
+		if (*p != ' ') {
+			if (spc == 1)
+				argp = p;
+			spc = 0;
 		}
-		if (*p == ' ' || *p == '\t' || *p == '\0') {
+		if (*p == ' ' || fin) {
 			if (spc == 1)
 				continue;
-			if (spc == 0 && (numspc % numparams == 0)) {
-				if (*p == '\0')
-					eolst = 1;
-				else
-					eolst = 0;
-				*p = '\0'; 	/* terminate arg string */
-				endp = p + 1;			
-				excbuf[0] = '\0';
-				/* Is arg a var? */
-				if (!inlist) {
-					sizof = sizeof(tmpbuf);
-					t = tmpbuf;
-					if (isvar(&argp, &t, sizof)) {
-						if ((contbuf = strndup(endp,
-						    BUFSIZE)) == NULL)
-							return(FALSE);
-						*p = ' ';
-						(void)(strlcpy(argbuf, tmpbuf,
-						    sizof) >= sizof);
-						p = argp = argbuf;
-						spc = 1;
-						foundlst = inlist = 1;
-						continue;
-					}
-				}				
-				if (strlcpy(excbuf, cmdp, sizeof(excbuf))
-				     >= sizeof(excbuf))
-					return (dobeep_msg("strlcpy error"));
-				if (strlcat(excbuf, s, sizeof(excbuf))
-				    >= sizeof(excbuf))
-					return (dobeep_msg("strlcat error"));
-				if (strlcat(excbuf, argp, sizeof(excbuf))
-				    >= sizeof(excbuf))
-					return (dobeep_msg("strlcat error"));
-
-				excline(excbuf);
-#ifdef  MGLOG
-				mglog_execbuf("  ", excbuf, argbuf, argp,
-				    eolst, inlist, cmdp, p, contbuf);
-#endif
-				*p = ' ';	/* so 'for' loop can continue */
-				if (eolst) {
-					if (contbuf != NULL) {
-						(void)strlcpy(argbuf, contbuf,
-						    sizeof(argbuf));
-						free(contbuf);
-						contbuf = NULL;
-						p = argp = argbuf;
-						foundlst = 1;
-						inlist = 0;
-						if (rpar)
-							fin = 1;
-						continue;
-					}
-					spc = 1;
-					inlist = 0;
+
+			if (*p == ' ') {
+				*p = '\0';	/* terminate arg string */
+			}
+			endp = p + 1;
+			excbuf[0] = '\0';
+			varbuf[0] = '\0';
+			contbuf[0] = '\0';			
+			sizof = sizeof(varbuf);
+			v = varbuf;
+			if (isvar(&argp, &v, sizof)) {
+				(void)(strlcat(varbuf, " ",
+                                    sizof) >= sizof);
+
+				*p = ' ';
+
+				(void)(strlcpy(contbuf, endp,
+				    sizeof(contbuf)) >= sizeof(contbuf));
+
+				(void)(strlcat(varbuf, contbuf,
+				    sizof) >= sizof);
+
+				(void)(strlcpy(argbuf, varbuf,
+				    sizof) >= sizof);
+
+				p = argp = argbuf;
+				while (*p != ' ') {
+					if (*p == '\0')
+						break;
+					p++;
 				}
-				if (eolst && rpar)
-					fin = 1;
+				*p = '\0';
+				spc = 1;
+				fin = 0;
 			}
-			numspc++;
+			if (strlcpy(excbuf, cmdp, sizeof(excbuf))
+			    >= sizeof(excbuf))
+				return (dobeep_msg("strlcpy error"));
+			if (strlcat(excbuf, s, sizeof(excbuf))
+			    >= sizeof(excbuf))
+				return (dobeep_msg("strlcat error"));
+			if (strlcat(excbuf, argp, sizeof(excbuf))
+			    >= sizeof(excbuf))
+				return (dobeep_msg("strlcat error"));
+
+			excline(excbuf);
+
+			if (fin)
+				break;
+
+			*p = ' ';		/* unterminate arg string */
 			spc = 1;
-		} else {
-			if (spc == 1)
-				if ((numparams == 1) ||
-				    ((numspc + 1) % numparams) == 0)
-					argp = p;
-			spc = 0;
 		}
 	}
 	return (TRUE);
@@ -232,18 +353,18 @@ multiarg(char *funstr)
  * Is an item a value or a variable?
  */
 static int
-isvar(char **argp, char **tmpbuf, int sizof)
+isvar(char **argp, char **varbuf, int sizof)
 {
 	struct varentry *v1 = NULL;
 
 	if (SLIST_EMPTY(&varhead))
 		return (FALSE);
 #ifdef  MGLOG
-	mglog_isvar(*tmpbuf, *argp, sizof);
+	mglog_isvar(*varbuf, *argp, sizof);
 #endif
 	SLIST_FOREACH(v1, &varhead, entry) {
 		if (strcmp(*argp, v1->name) == 0) {
-			(void)(strlcpy(*tmpbuf, v1->vals, sizof) >= sizof);
+			(void)(strlcpy(*varbuf, v1->vals, sizof) >= sizof);
 			return (TRUE);
 		}
 	}
@@ -252,7 +373,7 @@ isvar(char **argp, char **tmpbuf, int sizof)
 
 
 /*
- * The (define string _must_ adhere to the regex in foundparen.
+ * The define string _must_ adhere to the regex in parsexp().
  * This is not the correct way to do parsing but it does highlight
  * the issues.
  */
@@ -260,28 +381,22 @@ static int
 foundvar(char *defstr)
 {
 	struct varentry *vt, *v1 = NULL;
-	const char	 e[2] = "e", t[2] = "t";
-	char		*p, *vnamep, *vendp = NULL, *valp, *o;
-	int		 spc, foundlist = 0;
-
-	p = defstr + 1;         /* move past first '(' char.    */
-	p = skipwhite(p);    	/* find first char of 'define'. */
-	p = strstr(p, e);	/* find first 'e' in 'define'.	*/
-	p = strstr(++p, e);	/* find second 'e' in 'define'.	*/
-	p++;			/* move past second 'e'.	*/
-	vnamep = skipwhite(p);  /* find first char of var name. */
+	const char	 t[2] = "t";
+	char		*p, *vnamep, *vendp = NULL, *valp;
+	int		 spc;
+
+	p = strstr(defstr, " ");        /* move to first ' ' char.    */
+	vnamep = skipwhite(p);  	/* find first char of var name. */
 	vendp = vnamep;
 
 	/* now find the end of the list name */
 	while (1) {
 		++vendp;
-		if (*vendp == '(') {
-			foundlist = 1;
-			break;
-		} else if (*vendp == ' ' || *vendp == '\t')
+		if (*vendp == ' ')
 			break;
 	}
 	*vendp = '\0';
+
 	/*
 	 * Check list name is not an existing function.
 	 * Although could this be allowed? Shouldn't context dictate?
@@ -291,7 +406,8 @@ foundvar(char *defstr)
 
 	p = ++vendp;
 	p = skipwhite(p);
-	if (foundlist) {
+
+	if ((*p == 'l') && (*(p + 1) == 'i') && (*(p + 2) == 's')) {
 		p = strstr(p, t);	/* find 't' in 'list'.	*/
 		valp = skipwhite(++p);	/* find first value	*/
 	} else
@@ -319,36 +435,25 @@ foundvar(char *defstr)
 	spc = 1;
 	/* now loop through values in list value string while counting them */
 	for (p = valp; *p != '\0'; p++) {
-		if (*p == ' ' || *p == '\t') {
-			if (spc == 0)
-				vendp = p;
-			spc = 1;
-		} else if (*p == ')') {
-			o = p - 1;
-			if (*o != ' ' && *o != '\t')
-				vendp = p;
-			break;
-		} else {
+		if (*p != ' ' && *p != '\t') {
 			if (spc == 1)
 				v1->count++;
 			spc = 0;
 		}
 	}
-	if (vendp)
-		*vendp = '\0';
-
 	if ((v1->vals = strndup(valp, BUFSIZE)) == NULL)
 		return(dobeep_msg("strndup error"));
 
 #ifdef  MGLOG
-        mglog_misc("var:%s\t#items:%d\tvals:%s\n", vnamep, v1->count, v1->vals);
+        mglog_misc("var:%s\t#items:%d\tvals:|%s|\n", vnamep, v1->count, v1->vals);
 #endif
 
 	return (TRUE);
 }
 
 /*
- * Finished with evaluation, so clean up any vars.
+ * Finished with buffer evaluation, so clean up any vars.
+ * Perhaps keeps them in mg even after use,...
  */
 int
 clearvars(void)
@@ -366,62 +471,26 @@ clearvars(void)
 }
 
 /*
- * Line has a '(' as the first non-white char.
- * Do some very basic parsing of line with '(' as the first character.
- * Multi-line not supported at the moment, To do.
+ * Finished with block evaluation, so clean up any expressions.
  */
-int
-foundparen(char *funstr)
+static void
+clearexp(void)
 {
-	char	*regs, *p;
-	int      pctr;
+	struct expentry	*e1 = NULL;
 
-	pctr = 0;
-
-	/*
-	 * Check for blocks of code with opening and closing ().
-	 * One block = (cmd p a r a m)
-	 * Two blocks = (cmd p a r a m s)(hola)
-	 * Two blocks = (cmd p a r (list a m s))(hola)
-	 * Only single line at moment, but more for multiline.
-	 */
-	p = funstr;
-	while (*p != '\0') {
-		if (*p == '(') {
-			pctr++;
-		} else if (*p == ')') {
-			pctr--;
-		}
-		p++;
+	while (!SLIST_EMPTY(&exphead)) {
+		e1 = SLIST_FIRST(&exphead);
+		SLIST_REMOVE_HEAD(&exphead, eentry);
+		free(e1->exp);
+		free(e1);
 	}
-	if (pctr != 0)
-		return(dobeep_msg("Opening and closing parentheses error"));
-
-	/* Does the line have a list 'define' like: */
-	/* (define alist(list 1 2 3 4)) */
-	regs = "^[(][\t ]*define[\t ]+[^\t (]+[\t ]*[(][\t ]*list[\t ]+"\
-		"[^\t ]+.*[)][\t ]*[)]";
-	if (doregex(regs, funstr))
-		return(foundvar(funstr));
-
-	/* Does the line have a single variable 'define' like: */
-	/* (define i 0) */
-	regs = "^[(][\t ]*define[\t ]+[^\t (]+[\t ]*[^\t (]+[\t ]*[)]";
-        if (doregex(regs, funstr))
-                return(foundvar(funstr));
-
-	/* Does the line have an unrecognised 'define' */
-	regs = "^[(][\t ]*define[\t ]+";
-        if (doregex(regs, funstr))
-                return(dobeep_msg("Invalid use of define"));
-
-	return(multiarg(funstr));
+	return;
 }
 
 /*
  * Test a string against a regular expression.
  */
-int
+static int
 doregex(char *r, char *e)
 {
 	regex_t  regex_buff;