debugger

src/cmd/db/command.c

@@ -0,0 +1,311 @@
+/*
+ *
+ *	debugger
+ *
+ */
+
+#include "defs.h"
+#include "fns.h"
+
+char	BADEQ[] = "unexpected `='";
+
+BOOL	executing;
+extern	char	*lp;
+
+char	eqformat[ARB] = "z";
+char	stformat[ARB] = "zMi";
+
+ADDR	ditto;
+
+ADDR	dot;
+WORD	dotinc;
+WORD	adrval, cntval, loopcnt;
+int	adrflg, cntflg;
+
+/* command decoding */
+
+int
+command(char *buf, int defcom)
+{
+	char	*reg;
+	char	savc;
+	char	*savlp=lp;
+	char	savlc = lastc;
+	char	savpc = peekc;
+	static char lastcom = '=', savecom = '=';
+
+	if (defcom == 0)
+		defcom = lastcom;
+	if (buf) {
+		if (*buf==EOR)
+			return(FALSE);
+		clrinp();
+		lp=buf;
+	}
+	do {
+		adrflg=expr(0);		/* first address */
+		if (adrflg){
+			dot=expv;
+			ditto=expv;
+		}
+		adrval=dot;
+
+		if (rdc()==',' && expr(0)) {	/* count */
+			cntflg=TRUE;
+			cntval=expv;
+		} else {
+			cntflg=FALSE;
+			cntval=1;
+			reread();
+		}
+
+		if (!eol(rdc()))
+			lastcom=lastc;		/* command */
+		else {
+			if (adrflg==0)
+				dot=inkdot(dotinc);
+			reread();
+			lastcom=defcom;
+		}
+		switch(lastcom) {
+		case '/':
+		case '=':
+		case '?':
+			savecom = lastcom;
+			acommand(lastcom);
+			break;
+
+		case '>':
+			lastcom = savecom; 
+			savc=rdc();
+			if (reg=regname(savc))
+				rput(correg, reg, dot);
+			else	
+				error("bad variable");
+			break;
+
+		case '!':
+			lastcom=savecom;
+			shell(); 
+			break;
+
+		case '$':
+			lastcom=savecom;
+			printdollar(nextchar()); 
+			break;
+
+		case ':':
+			if (!executing) { 
+				executing=TRUE;
+				subpcs(nextchar());
+				executing=FALSE;
+				lastcom=savecom;
+			}
+			break;
+
+		case 0:
+			prints(DBNAME);
+			break;
+
+		default: 
+			error("bad command");
+		}
+		flushbuf();
+	} while (rdc()==';');
+	if (buf == 0)
+		reread();
+	else {
+		clrinp();
+		lp=savlp;
+		lastc = savlc;
+		peekc = savpc;
+	}
+
+	if(adrflg)
+		return dot;
+	return 1;
+}
+
+/*
+ * [/?][wml]
+ */
+
+void
+acommand(int pc)
+{
+	int eqcom;
+	Map *map;
+	char *fmt;
+	char buf[512];
+
+	if (pc == '=') {
+		eqcom = 1;
+		fmt = eqformat;
+		map = dotmap;
+	} else {
+		eqcom = 0;
+		fmt = stformat;
+		if (pc == '/')
+			map = cormap;
+		else
+			map = symmap;
+	}
+	if (!map) {
+		sprint(buf, "no map for %c", pc);
+		error(buf);
+	}
+
+	switch (rdc())
+	{
+	case 'm':
+		if (eqcom)
+			error(BADEQ); 
+		cmdmap(map);
+		break;
+
+	case 'L':
+	case 'l':
+		if (eqcom)
+			error(BADEQ); 
+		cmdsrc(lastc, map);
+		break;
+
+	case 'W':
+	case 'w':
+		if (eqcom)
+			error(BADEQ); 
+		cmdwrite(lastc, map);
+		break;
+
+	default:
+		reread();
+		getformat(fmt);
+		scanform(cntval, !eqcom, fmt, map, eqcom);
+	}
+}
+
+void
+cmdsrc(int c, Map *map)
+{
+	u32int w;
+	long locval, locmsk;
+	ADDR savdot;
+	ushort sh;
+	char buf[512];
+	int ret;
+
+	if (c == 'L')
+		dotinc = 4;
+	else
+		dotinc = 2;
+	savdot=dot;
+	expr(1); 
+	locval=expv;
+	if (expr(0))
+		locmsk=expv; 
+	else
+		locmsk = ~0;
+	if (c == 'L')
+		while ((ret = get4(map, dot, &w)) > 0 &&  (w&locmsk) != locval)
+			dot = inkdot(dotinc);
+	else
+		while ((ret = get2(map, dot, &sh)) > 0 && (sh&locmsk) != locval)
+			dot = inkdot(dotinc);
+	if (ret < 0) { 
+		dot=savdot; 
+		error("%r");
+	}
+	symoff(buf, 512, dot, CANY);
+	dprint(buf);
+}
+
+static char badwrite[] = "can't write process memory or text image";
+
+void
+cmdwrite(int wcom, Map *map)
+{
+	ADDR savdot;
+	char *format;
+	int pass;
+
+	if (wcom == 'w')
+		format = "x";
+	else
+		format = "X";
+	expr(1);
+	pass = 0;
+	do {
+		pass++;  
+		savdot=dot;
+		exform(1, 1, format, map, 0, pass);
+		dot=savdot;
+		if (wcom == 'W') {
+			if (put4(map, dot, expv) <= 0)
+				error(badwrite);
+		} else {
+			if (put2(map, dot, expv) <= 0)
+				error(badwrite);
+		}
+		savdot=dot;
+		dprint("=%8t"); 
+		exform(1, 0, format, map, 0, pass);
+		newline();
+	} while (expr(0));
+	dot=savdot;
+}
+
+/*
+ * collect a register name; return register offset
+ * this is not what i'd call a good division of labour
+ */
+
+char *
+regname(int regnam)
+{
+	static char buf[64];
+	char *p;
+	int c;
+
+	p = buf;
+	*p++ = regnam;
+	while (isalnum(c = readchar())) {
+		if (p >= buf+sizeof(buf)-1)
+			error("register name too long");
+		*p++ = c;
+	}
+	*p = 0;
+	reread();
+	return (buf);
+}
+
+/*
+ * shell escape
+ */
+
+void
+shell(void)
+{
+	int	rc, unixpid;
+	char *argp = lp;
+
+	while (lastc!=EOR)
+		rdc();
+	if ((unixpid=fork())==0) {
+		*lp=0;
+		execl("/bin/rc", "rc", "-c", argp, 0);
+		exits("execl");				/* botch */
+	} else if (unixpid == -1) {
+		error("cannot fork");
+	} else {
+		mkfault = 0;
+		while ((rc = waitpid()) != unixpid){
+			if(rc == -1 && mkfault){
+				mkfault = 0;
+				continue;
+			}
+			break;
+		}
+		prints("!"); 
+		reread();
+	}
+}