4 files changed, 22 insertions, 20 deletions

diff --git a/src/cmd/cgo/doc.go b/src/cmd/cgo/doc.go
index 63413825a..a4219867c 100644
--- a/src/cmd/cgo/doc.go
+++ b/src/cmd/cgo/doc.go
@@ -92,5 +92,8 @@ process of using cgo.  See $GOROOT/misc/cgo/stdio and
 $GOROOT/misc/cgo/gmp for examples.
 
 Cgo does not yet work with gccgo.
+
+See "C? Go? Cgo!" for an introduction to using cgo:
+http://blog.golang.org/2011/03/c-go-cgo.html
 */
 package documentation
diff --git a/src/cmd/gc/obj.c b/src/cmd/gc/obj.c
index 456aabb88..f99f93bda 100644
--- a/src/cmd/gc/obj.c
+++ b/src/cmd/gc/obj.c
@@ -127,7 +127,6 @@ static void
 outhist(Biobuf *b)
 {
 	Hist *h;
-	int i, depth = 0;
 	char *p, ds[] = {'c', ':', '/', 0};
 
 	for(h = hist; h != H; h = h->link) {
@@ -164,14 +163,7 @@ outhist(Biobuf *b)
 					outzfile(b, p);
 				}
 			}
-			if(h->offset > 0) {
-				//line directive
-				depth++;
-			}
-		} else if(depth > 0) {
-			for(i = 0; i < depth; i++)
-				zhist(b, h->line, h->offset);
-			depth = 0;
+		
 		}
 		zhist(b, h->line, h->offset);
 	}
diff --git a/src/cmd/godoc/doc.go b/src/cmd/godoc/doc.go
index dc98b0eca..088889d2a 100644
--- a/src/cmd/godoc/doc.go
+++ b/src/cmd/godoc/doc.go
@@ -126,5 +126,8 @@ one may run godoc as follows:
 
 	godoc -http=:6060 -zip=go.zip -goroot=$HOME/go
 
+
+See "Godoc: documenting Go code" for how to write good comments for godoc:
+http://blog.golang.org/2011/03/godoc-documenting-go-code.html
 */
 package documentation
diff --git a/src/cmd/ld/dwarf.c b/src/cmd/ld/dwarf.c
index d8ca27ace..77536018a 100644
--- a/src/cmd/ld/dwarf.c
+++ b/src/cmd/ld/dwarf.c
@@ -1578,13 +1578,16 @@ addhistfile(char *zentry)
 		histfile[histfilesize++] = "<eof>";
 
 	fname = decodez(zentry);
+//	print("addhistfile %d: %s\n", histfilesize, fname);
 	if (fname == 0)
 		return -1;
+
 	// Don't fill with duplicates (check only top one).
 	if (strcmp(fname, histfile[histfilesize-1]) == 0) {
 		free(fname);
 		return histfilesize - 1;
 	}
+
 	histfile[histfilesize++] = fname;
 	return histfilesize - 1;
 }
@@ -1608,11 +1611,13 @@ finddebugruntimepath(void)
 }
 
 // Go's runtime C sources are sane, and Go sources nest only 1 level,
-// so 16 should be plenty.
+// so a handful would be plenty, if it weren't for the fact that line
+// directives can push an unlimited number of them.
 static struct {
 	int file;
 	vlong line;
-} includestack[16];
+} *includestack;
+static int includestacksize;
 static int includetop;
 static vlong absline;
 
@@ -1629,17 +1634,15 @@ static Linehist *linehist;
 static void
 checknesting(void)
 {
-	int i;
-
 	if (includetop < 0) {
 		diag("dwarf: corrupt z stack");
 		errorexit();
 	}
-	if (includetop >= nelem(includestack)) {
-		diag("dwarf: nesting too deep");
-		for (i = 0; i < nelem(includestack); i++)
-			diag("\t%s", histfile[includestack[i].file]);
-		errorexit();
+	if (includetop >= includestacksize) {
+		includestacksize += 1;
+		includestacksize <<= 2;
+//		print("checknesting: growing to %d\n", includestacksize);
+		includestack = realloc(includestack, includestacksize * sizeof *includestack);	       
 	}
 }
 
@@ -1669,6 +1672,7 @@ inithist(Auto *a)
 	// Clear the history.
 	clearhistfile();
 	includetop = 0;
+	checknesting();
 	includestack[includetop].file = 0;
 	includestack[includetop].line = -1;
 	absline = 0;
@@ -1682,10 +1686,10 @@ inithist(Auto *a)
 	for (; a; a = a->link) {
 		if (a->type == D_FILE) {  // 'z'
 			int f = addhistfile(a->asym->name);
-			if (f < 0) {	   // pop file
+			if (f < 0) {	// pop file
 				includetop--;
 				checknesting();
-			} else if(f != includestack[includetop].file) { // pushed a new file
+			} else {	// pushed a file (potentially same)
 				includestack[includetop].line += a->aoffset - absline;
 				includetop++;
 				checknesting();