svgpic: new program to convert pic to svg

This is an experiment.
Like tpic it's a copy-and-paste fork of pic.

Change-Id: Ia22772bd5881c7904a6d8f8e0b46fde8cea89cbd
Reviewed-on: https://plan9port-review.googlesource.com/2920
Reviewed-by: Russ Cox <rsc@swtch.com>

1 files changed, 104 insertions, 0 deletions

diff --git a/src/cmd/svgpic/symtab.c b/src/cmd/svgpic/symtab.c
new file mode 100644
index 00000000..059d3be7
--- /dev/null
+++ b/src/cmd/svgpic/symtab.c
@@ -0,0 +1,104 @@
+#include <stdio.h>
+#include <stdlib.h>
+#include <ctype.h>
+#include <string.h>
+#include "pic.h"
+#include "y.tab.h"
+
+YYSTYPE getvar(char *s)	/* return value of variable s (usually pointer) */
+{
+	struct symtab *p;
+	static YYSTYPE bug;
+
+	p = lookup(s);
+	if (p == NULL) {
+		if (islower((int) s[0]))
+			ERROR "no such variable as %s", s WARNING;
+		else
+			ERROR "no such place as %s", s WARNING;
+		return(bug);
+	}
+	return(p->s_val);
+}
+
+double getfval(char *s)	/* return float value of variable s */
+{
+	YYSTYPE y;
+
+	y = getvar(s);
+	return y.f;
+}
+
+void setfval(char *s, double f)	/* set variable s to f */
+{
+	struct symtab *p;
+
+	if ((p = lookup(s)) != NULL)
+		p->s_val.f = f;
+}
+
+struct symtab *makevar(char *s, int t, YYSTYPE v)	/* make variable named s in table */
+		/* assumes s is static or from tostring */
+{
+	struct symtab *p;
+
+	for (p = stack[nstack].p_symtab; p != NULL; p = p->s_next)
+		if (strcmp(s, p->s_name) == 0)
+			break;
+	if (p == NULL) {	/* it's a new one */
+		p = (struct symtab *) malloc(sizeof(struct symtab));
+		if (p == NULL)
+			ERROR "out of symtab space with %s", s FATAL;
+		p->s_next = stack[nstack].p_symtab;
+		stack[nstack].p_symtab = p;	/* stick it at front */
+	}
+	p->s_name = s;
+	p->s_type = t;
+	p->s_val = v;
+	return(p);
+}
+
+struct symtab *lookup(char *s)	/* find s in symtab */
+{
+	int i;
+	struct symtab *p;
+
+	for (i = nstack; i >= 0; i--)	/* look in each active symtab */
+		for (p = stack[i].p_symtab; p != NULL; p = p->s_next)
+			if (strcmp(s, p->s_name) == 0)
+				return(p);
+	return(NULL);
+}
+
+void freesymtab(struct symtab *p)	/* free space used by symtab at p */
+{
+	struct symtab *q;
+
+	for ( ; p != NULL; p = q) {
+		q = p->s_next;
+		free(p->s_name);	/* assumes done with tostring */
+		free((char *)p);
+	}
+}
+
+void freedef(char *s)	/* free definition for string s */
+{
+	struct symtab *p, *q, *op;
+
+	for (p = op = q = stack[nstack].p_symtab; p != NULL; p = p->s_next) {
+		if (strcmp(s, p->s_name) == 0) { 	/* got it */
+			if (p->s_type != DEFNAME)
+				break;
+			if (p == op)	/* 1st elem */
+				stack[nstack].p_symtab = p->s_next;
+			else
+				q->s_next = p->s_next;
+			free(p->s_name);
+			free(p->s_val.p);
+			free((char *)p);
+			return;
+		}
+		q = p;
+	}
+	/* ERROR "%s is not defined at this point", s WARNING; */
+}