From 6bd0764167a0fbebb5ee90bf1a9c30e8d119442b Mon Sep 17 00:00:00 2001
From: cinap_lenrek <cinap_lenrek@felloff.net>
Date: Thu, 22 Nov 2018 15:09:54 +0100
Subject: [PATCH] snap: add debug flag, make debug less verbose

---
 sys/src/cmd/snap/read.c   | 23 ++++++++++++++---------
 sys/src/cmd/snap/snap.c   |  5 ++++-
 sys/src/cmd/snap/snapfs.c |  2 +-
 sys/src/cmd/snap/take.c   |  6 ++++++
 4 files changed, 25 insertions(+), 11 deletions(-)

diff --git a/sys/src/cmd/snap/read.c b/sys/src/cmd/snap/read.c
index 035deebf1..ad3188008 100644
--- a/sys/src/cmd/snap/read.c
+++ b/sys/src/cmd/snap/read.c
@@ -124,7 +124,7 @@ readdata(Biobuf *b)
 }
 
 static Seg*
-readseg(Seg **ps, Biobuf *b, Proc *plist)
+readseg(Seg **ps, Biobuf *b, Proc *plist, char *name)
 {
 	Seg *s;
 	Page **pp;
@@ -141,6 +141,9 @@ readseg(Seg **ps, Biobuf *b, Proc *plist)
 	|| Breaduvlong(b, &s->len) < 0)
 		sysfatal("error reading segment: %r");
 
+	if(debug)
+		fprint(2, "readseg %.8llux - %.8llux %s\n", s->offset, s->offset + s->len, name);
+
 	npg = (s->len + Pagesize-1)/Pagesize;
 	s->npg = npg;
 
@@ -159,7 +162,7 @@ readseg(Seg **ps, Biobuf *b, Proc *plist)
 		switch(t = Bgetc(b)) {
 		case 'z':
 			pp[i] = datapage(zeros, len);
-			if(debug)
+			if(debug > 1)
 				fprint(2, "0x%.8llux all zeros\n", s->offset+(uvlong)i*Pagesize);
 			break;
 		case 'm':
@@ -170,7 +173,7 @@ readseg(Seg **ps, Biobuf *b, Proc *plist)
 			pp[i] = findpage(plist, pid, t, off);
 			if(pp[i] == nil)
 				sysfatal("bad page reference in snapshot");
-			if(debug)
+			if(debug > 1)
 				fprint(2, "0x%.8llux same as %s pid %lud 0x%.8llux\n",
 					s->offset+(uvlong)i*Pagesize, t=='m'?"mem":"text", pid, off);
 			break;
@@ -178,7 +181,7 @@ readseg(Seg **ps, Biobuf *b, Proc *plist)
 			if((n=Bread(b, buf, len)) != len)
 				sysfatal("short read of segment %d/%d at %llx: %r", n, len, Boffset(b));
 			pp[i] = datapage(buf, len);
-			if(debug)
+			if(debug > 1)
 				fprint(2, "0x%.8llux is raw data\n", s->offset+(uvlong)i*Pagesize);
 			break;
 		default:
@@ -233,11 +236,13 @@ readsnap(Biobuf *b)
 				sysfatal("bad segment count: %d", n);
 			p->nseg = n;
 			p->seg = emalloc(n*sizeof(*p->seg));
-			for(i=0; i<n; i++)
-				readseg(&p->seg[i], b, plist);
-		} else if(strcmp(q, "text") == 0)
-			readseg(&p->text, b, plist);
-		else
+			for(i=0; i<n; i++){
+				snprint(buf, sizeof(buf), "[%d]", i);
+				readseg(&p->seg[i], b, plist, buf);
+			}
+		} else if(strcmp(q, "text") == 0) {
+			readseg(&p->text, b, plist, q);
+		} else
 			sysfatal("unknown section");
 	}
 	return plist;
diff --git a/sys/src/cmd/snap/snap.c b/sys/src/cmd/snap/snap.c
index a64d688aa..2cce28af6 100644
--- a/sys/src/cmd/snap/snap.c
+++ b/sys/src/cmd/snap/snap.c
@@ -6,7 +6,7 @@
 void
 usage(void)
 {
-	fprint(2, "usage: %s [-o snapfile] pid...\n", argv0);
+	fprint(2, "usage: %s [-d] [-o snapfile] pid...\n", argv0);
 	exits("usage");
 }
 
@@ -22,6 +22,9 @@ main(int argc, char **argv)
 
 	ofile = "/fd/1";
 	ARGBEGIN{
+	case 'd':
+		debug++;
+		break;
 	case 'o':
 		ofile = ARGF();
 		break;
diff --git a/sys/src/cmd/snap/snapfs.c b/sys/src/cmd/snap/snapfs.c
index 6b695f572..cfae7683c 100644
--- a/sys/src/cmd/snap/snapfs.c
+++ b/sys/src/cmd/snap/snapfs.c
@@ -139,7 +139,7 @@ main(int argc, char **argv)
 		chatty9p++;
 		break;
 	case 'd':
-		debug = 1;
+		debug++;
 		break;
 	case 'a':
 		mflag = MAFTER;
diff --git a/sys/src/cmd/snap/take.c b/sys/src/cmd/snap/take.c
index 64a454fbf..bb139ef11 100644
--- a/sys/src/cmd/snap/take.c
+++ b/sys/src/cmd/snap/take.c
@@ -89,6 +89,9 @@ readseg(int fd, uvlong off, uvlong len, char *name)
 	Seg *s;
 	int n;
 
+	if(debug)
+		fprint(2, "readseg %.8llux - %.8llux %s\n", off, off+len, name);
+
 	s = emalloc(sizeof(*s));
 	s->name = estrdup(name);
 	if(seek(fd, off, 0) < 0) {
@@ -263,6 +266,9 @@ snap(long pid, int usetext)
 	/* stack hack: figure sp so don't need to page in the whole segment */
 	if(stacklen) {
 		sp = stackptr(proc, fd);
+		if(debug)
+			fprint(2, "stackseg %.8llux - %.8llux sp %.8llux\n",
+				stackoff, stackoff+stacklen, sp);
 		if(stackoff <= sp && sp < stackoff+stacklen) {
 			off = sp - 8*1024;
 		} else {	/* stack pointer not in segment.  thread library? */