Add set/show debug dwarf-line.

gdb/ChangeLog:

	* NEWS: Mention "set debug dwarf-line".
	* dwarf2read.c (dwarf_line_debug): New static global.
	(add_include_dir): Add debug dwarf-line support.
	(add_file_name, dwarf_record_line, dwarf_finish_line): Ditto.
	(_initialize_dwarf2_read): New parameter "debug dwarf-line".

gdb/doc/ChangeLog:

	* gdb.texinfo (Debugging Output): Mention set/show debug dwarf-line.

5 files changed, 65 insertions, 2 deletions

diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 8122b98..e531727 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,5 +1,13 @@
 2015-05-27  Doug Evans  <dje@google.com>
 
+	* NEWS: Mention "set debug dwarf-line".
+	* dwarf2read.c (dwarf_line_debug): New static global.
+	(add_include_dir): Add debug dwarf-line support.
+	(add_file_name, dwarf_record_line, dwarf_finish_line): Ditto.
+	(_initialize_dwarf2_read): New parameter "debug dwarf-line".
+
+2015-05-27  Doug Evans  <dje@google.com>
+
 	* cp-namespace.c (cp_lookup_nested_symbol): New arg "domain".
 	All callers updated.
 	(cp_lookup_nested_symbol_1, find_symbol_in_baseclass): Ditto.
diff --git a/gdb/NEWS b/gdb/NEWS
index 4c4e28c..bbfb55d 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -112,6 +112,10 @@ maint set dwarf max-cache-age
 maint show dwarf max-cache-age
   Renamed from "maint show dwarf2 max-cache-age".
 
+set debug dwarf-line
+show debug dwarf-line
+  Control display of debugging info regarding DWARF line processing.
+
 set max-completions
 show max-completions
   Set the maximum number of candidates to be considered during
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index 490afe2..171d30e 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,7 @@
+2015-05-27  Doug Evans  <dje@google.com>
+
+	* gdb.texinfo (Debugging Output): Mention set/show debug dwarf-line.
+
 2015-05-26  Doug Evans  <dje@google.com>
 
 	* gdb.texinfo (Debugging Output): Update for DWARF "set debug"
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 6cc6c7e..9ea846a 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -23417,6 +23417,14 @@ The value is the number of nesting levels to print.
 A value of zero turns off the display.
 @item show debug dwarf-die
 Show the current state of DWARF DIE debugging.
+@item set debug dwarf-line
+@cindex DWARF Line Tables
+Turns on or off display of debugging messages related to reading
+DWARF line tables.  The default is 0 (off).
+A value of 1 provides basic information.
+A value greater than 1 provides more verbose information.
+@item show debug dwarf-line
+Show the current state of DWARF line table debugging.
 @item set debug dwarf-read
 @cindex DWARF Reading
 Turns on or off display of debugging messages related to reading
diff --git a/gdb/dwarf2read.c b/gdb/dwarf2read.c
index 8e30ff3..e6d6b30 100644
--- a/gdb/dwarf2read.c
+++ b/gdb/dwarf2read.c
@@ -84,6 +84,9 @@ static unsigned int dwarf_read_debug = 0;
 /* When non-zero, dump DIEs after they are read in.  */
 static unsigned int dwarf_die_debug = 0;
 
+/* When non-zero, dump line number entries as they are read in.  */
+static unsigned int dwarf_line_debug = 0;
+
 /* When non-zero, cross-check physname against demangler.  */
 static int check_physname = 0;
 
@@ -17152,6 +17155,10 @@ free_line_header_voidp (void *arg)
 static void
 add_include_dir (struct line_header *lh, const char *include_dir)
 {
+  if (dwarf_line_debug >= 2)
+    fprintf_unfiltered (gdb_stdlog, "Adding dir %u: %s\n",
+			lh->num_include_dirs + 1, include_dir);
+
   /* Grow the array if necessary.  */
   if (lh->include_dirs_size == 0)
     {
@@ -17181,6 +17188,10 @@ add_file_name (struct line_header *lh,
 {
   struct file_entry *fe;
 
+  if (dwarf_line_debug >= 2)
+    fprintf_unfiltered (gdb_stdlog, "Adding file %u: %s\n",
+			lh->num_file_names + 1, name);
+
   /* Grow the array if necessary.  */
   if (lh->file_names_size == 0)
     {
@@ -17529,6 +17540,14 @@ dwarf_record_line (struct gdbarch *gdbarch, struct subfile *subfile,
 {
   CORE_ADDR addr = gdbarch_addr_bits_remove (gdbarch, address);
 
+  if (dwarf_line_debug)
+    {
+      fprintf_unfiltered (gdb_stdlog,
+			  "Recording line %u, file %s, address %s\n",
+			  line, lbasename (subfile->name),
+			  paddress (gdbarch, address));
+    }
+
   (*p_record_line) (subfile, line, addr);
 }
 
@@ -17541,8 +17560,18 @@ static void
 dwarf_finish_line (struct gdbarch *gdbarch, struct subfile *subfile,
 		   CORE_ADDR address, record_line_ftype p_record_line)
 {
-  if (subfile != NULL)
-    dwarf_record_line (gdbarch, subfile, 0, address, p_record_line);
+  if (subfile == NULL)
+    return;
+
+  if (dwarf_line_debug)
+    {
+      fprintf_unfiltered (gdb_stdlog,
+			  "Finishing current line, file %s, address %s\n",
+			  lbasename (subfile->name),
+			  paddress (gdbarch, address));
+    }
+
+  dwarf_record_line (gdbarch, subfile, 0, address, p_record_line);
 }
 
 /* Subroutine of dwarf_decode_lines to simplify it.
@@ -23321,6 +23350,16 @@ The value is the maximum depth to print."),
 			     NULL,
 			     &setdebuglist, &showdebuglist);
 
+  add_setshow_zuinteger_cmd ("dwarf-line", no_class, &dwarf_line_debug, _("\
+Set debugging of the dwarf line reader."), _("\
+Show debugging of the dwarf line reader."), _("\
+When enabled (non-zero), line number entries are dumped as they are read in.\n\
+A value of 1 (one) provides basic information.\n\
+A value greater than 1 provides more verbose information."),
+			     NULL,
+			     NULL,
+			     &setdebuglist, &showdebuglist);
+
   add_setshow_boolean_cmd ("check-physname", no_class, &check_physname, _("\
 Set cross-checking of \"physname\" code against demangler."), _("\
 Show cross-checking of \"physname\" code against demangler."), _("\