* dwarf.c (struct unit): Add filename and abs_filename fields.

	(build_address_map): Set new fields when reading unit.
	(dwarf_lookup_pc): If we don't find an entry in the line table,
	just return the main file name.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@195257 138bc75d-0d04-0410-961f-82ee72b054a4

2 files changed, 58 insertions, 2 deletions

diff --git a/libbacktrace/ChangeLog b/libbacktrace/ChangeLog
index 30382287f1c..25a56d92e22 100644
--- a/libbacktrace/ChangeLog
+++ b/libbacktrace/ChangeLog
@@ -1,3 +1,10 @@
+2013-01-16  Ian Lance Taylor  <iant@google.com>
+
+	* dwarf.c (struct unit): Add filename and abs_filename fields.
+	(build_address_map): Set new fields when reading unit.
+	(dwarf_lookup_pc): If we don't find an entry in the line table,
+	just return the main file name.
+
 2013-01-14  Richard Sandiford  <rdsandiford@googlemail.com>
 
 	Update copyright years.
diff --git a/libbacktrace/dwarf.c b/libbacktrace/dwarf.c
index 87392ddec8b..ce12bdc48a3 100644
--- a/libbacktrace/dwarf.c
+++ b/libbacktrace/dwarf.c
@@ -283,8 +283,12 @@ struct unit
   int addrsize;
   /* Offset into line number information.  */
   off_t lineoff;
+  /* Primary source file.  */
+  const char *filename;
   /* Compilation command working directory.  */
   const char *comp_dir;
+  /* Absolute file name, only set if needed.  */
+  const char *abs_filename;
   /* The abbreviations for this unit.  */
   struct abbrevs abbrevs;
 
@@ -1288,6 +1292,7 @@ build_address_map (struct backtrace_state *state, uintptr_t base_address,
       int have_ranges;
       uint64_t lineoff;
       int have_lineoff;
+      const char *filename;
       const char *comp_dir;
 
       if (info.reported_underflow)
@@ -1346,6 +1351,7 @@ build_address_map (struct backtrace_state *state, uintptr_t base_address,
       have_ranges = 0;
       lineoff = 0;
       have_lineoff = 0;
+      filename = NULL;
       comp_dir = NULL;
       for (i = 0; i < abbrev->num_attrs; ++i)
 	{
@@ -1394,6 +1400,10 @@ build_address_map (struct backtrace_state *state, uintptr_t base_address,
 		  have_lineoff = 1;
 		}
 	      break;
+	    case DW_AT_name:
+	      if (val.encoding == ATTR_VAL_STRING)
+		filename = val.u.string;
+	      break;
 	    case DW_AT_comp_dir:
 	      if (val.encoding == ATTR_VAL_STRING)
 		comp_dir = val.u.string;
@@ -1421,7 +1431,9 @@ build_address_map (struct backtrace_state *state, uintptr_t base_address,
 	  u->version = version;
 	  u->is_dwarf64 = is_dwarf64;
 	  u->addrsize = addrsize;
+	  u->filename = filename;
 	  u->comp_dir = comp_dir;
+	  u->abs_filename = NULL;
 	  u->lineoff = lineoff;
 	  u->abbrevs = abbrevs;
 	  memset (&abbrevs, 0, sizeof abbrevs);
@@ -2701,8 +2713,45 @@ dwarf_lookup_pc (struct backtrace_state *state, struct dwarf_data *ddata,
 				sizeof (struct line), line_search);
   if (ln == NULL)
     {
-      error_callback (data, "inconsistent DWARF line number info", 0);
-      return 0;
+      /* The PC is between the low_pc and high_pc attributes of the
+	 compilation unit, but no entry in the line table covers it.
+	 This implies that the start of the compilation unit has no
+	 line number information.  */
+
+      if (entry->u->abs_filename == NULL)
+	{
+	  const char *filename;
+
+	  filename = entry->u->filename;
+	  if (filename != NULL
+	      && !IS_ABSOLUTE_PATH (filename)
+	      && entry->u->comp_dir != NULL)
+	    {
+	      size_t filename_len;
+	      const char *dir;
+	      size_t dir_len;
+	      char *s;
+
+	      filename_len = strlen (filename);
+	      dir = entry->u->comp_dir;
+	      dir_len = strlen (dir);
+	      s = (char *) backtrace_alloc (state, dir_len + filename_len + 2,
+					    error_callback, data);
+	      if (s == NULL)
+		{
+		  *found = 0;
+		  return 0;
+		}
+	      memcpy (s, dir, dir_len);
+	      /* FIXME: Should use backslash if DOS file system.  */
+	      s[dir_len] = '/';
+	      memcpy (s + dir_len + 1, filename, filename_len + 1);
+	      filename = s;
+	    }
+	  entry->u->abs_filename = filename;
+	}
+
+      return callback (data, pc, entry->u->abs_filename, 0, NULL);
     }
 
   /* Search for function name within this unit.  */