[evolution-data-server] [CamelDebug] Change when backtraces are demangled in pointer tracker

[Milan Crha <mcrha src gnome org>]

commit 6e130c43ac6a45c18ed434448c24aa2886e0186b
Author: Milan Crha <mcrha redhat com>
Date:   Wed Jul 18 17:13:25 2018 +0200

    [CamelDebug] Change when backtraces are demangled in pointer tracker

 src/camel/camel-debug.c | 167 +++++++++++++++++++++++++++++++++++++++++-------
 src/camel/camel-debug.h |   2 +
 2 files changed, 146 insertions(+), 23 deletions(-)
---
diff --git a/src/camel/camel-debug.c b/src/camel/camel-debug.c
index 132c73dbb..e51dd2764 100644
--- a/src/camel/camel-debug.c
+++ b/src/camel/camel-debug.c
@@ -284,6 +284,8 @@ free_pt_data (gpointer ptr)
        g_free (ptd);
 }
 
+static void demangle_bt (GString *bt);
+
 static void
 dump_left_ptrs_cb (gpointer key,
                    gpointer value,
@@ -294,7 +296,11 @@ dump_left_ptrs_cb (gpointer key,
        gboolean have_info = ptd && ptd->info;
        gboolean have_bt = ptd && ptd->backtrace && ptd->backtrace->str && *ptd->backtrace->str;
 
+       if (have_bt)
+               demangle_bt (ptd->backtrace);
+
        *left = (*left) - 1;
+
        g_print ("      %p %s%s%s%s%s%s\n", key, have_info ? "(" : "", have_info ? ptd->info : "", have_info 
? ")" : "", have_bt ? "\n" : "", have_bt ? ptd->backtrace->str : "", have_bt && *left > 0 ? "\n" : "");
 }
 
@@ -337,6 +343,9 @@ dump_by_backtrace_cb (gpointer key,
                gboolean have_info = ptd && ptd->info;
                gboolean have_bt = ptd && ptd->backtrace && ptd->backtrace->str && *ptd->backtrace->str;
 
+               if (have_bt)
+                       demangle_bt (ptd->backtrace);
+
                *left = (*left) - 1;
 
                g_print ("      %d x %s%s%s%s%s%s\n", count, have_info ? "(" : "", have_info ? ptd->info : 
"", have_info ? ")" : "", have_bt ? "\n" : "", have_bt ? ptd->backtrace->str : "", have_bt && *left > 0 ? 
"\n" : "");
@@ -519,6 +528,81 @@ addr_lookup (gpointer addr,
 
 #endif /* HAVE_BACKTRACE_SYMBOLS */
 
+static void
+demangle_bt (GString *bt)
+{
+#ifdef HAVE_BACKTRACE_SYMBOLS
+       gchar **btparts;
+       gint ii;
+       gboolean any_changed = FALSE;
+
+       if (!bt || !bt->len)
+               return;
+
+       btparts = g_strsplit (bt->str, "\n", -1);
+       if (!btparts)
+               return;
+
+       g_string_truncate (bt, 0);
+
+       for (ii = 0; btparts[ii]; ii++) {
+               gint lineno = -1;
+               const gchar *file_path = NULL;
+               const gchar *str, *bt_sym;
+               gpointer btptr = NULL;
+
+               if (!g_str_has_prefix (btparts[ii], "0x") ||
+                   !strchr (btparts[ii], '\t') ||
+                   sscanf (btparts[ii], "%p\t", &btptr) != 1) {
+                       btptr = NULL;
+               }
+
+               if (btptr) {
+                       bt_sym = strchr (btparts[ii], '\t');
+                       if (bt_sym)
+                               bt_sym++;
+               } else {
+                       bt_sym = NULL;
+               }
+
+               if (!bt_sym || !*bt_sym) {
+                       if (bt->len)
+                               g_string_append_c (bt, '\n');
+                       g_string_append (bt, btparts[ii]);
+                       continue;
+               }
+
+               str = addr_lookup (btptr, &file_path, &lineno, bt_sym);
+
+               if (!str) {
+                       str = btparts[ii];
+                       file_path = NULL;
+                       lineno = -1;
+               }
+
+               if (!str)
+                       continue;
+
+               any_changed = TRUE;
+               if (bt->len)
+                       g_string_append (bt, "\n\t   by ");
+               g_string_append (bt, str);
+               if (str != btparts[ii])
+                       g_string_append (bt, "()");
+
+               if (file_path && lineno > 0) {
+                       const gchar *lastsep = strrchr (file_path, G_DIR_SEPARATOR);
+                       g_string_append_printf (bt, " at %s:%d", lastsep ? lastsep + 1 : file_path, lineno);
+               }
+       }
+
+       g_strfreev (btparts);
+
+       if (bt->len != 0 && any_changed)
+               g_string_insert (bt, 0, "\t   at ");
+#endif /* HAVE_BACKTRACE_SYMBOLS */
+}
+
 static GString *
 get_current_backtrace (void)
 {
@@ -539,27 +623,9 @@ get_current_backtrace (void)
 
        bt_str = g_string_new ("");
        for (ii = 2; ii < nptrs; ii++) {
-               gint lineno = -1;
-               const gchar *file_path = NULL;
-               const gchar *str = addr_lookup (bt[ii], &file_path, &lineno, bt_syms[ii]);
-               if (!str) {
-                       str = bt_syms[ii];
-                       file_path = NULL;
-                       lineno = -1;
-               }
-               if (!str)
-                       continue;
-
                if (bt_str->len)
-                       g_string_append (bt_str, "\n\t   by ");
-               g_string_append (bt_str, str);
-               if (str != bt_syms[ii])
-                       g_string_append (bt_str, "()");
-
-               if (file_path && lineno > 0) {
-                       const gchar *lastsep = strrchr (file_path, G_DIR_SEPARATOR);
-                       g_string_append_printf (bt_str, " at %s:%d", lastsep ? lastsep + 1 : file_path, 
lineno);
-               }
+                       g_string_append (bt_str, "\n");
+               g_string_append_printf (bt_str, "%p\t%s", bt[ii], bt_syms[ii]);
        }
 
        g_free (bt_syms);
@@ -567,8 +633,6 @@ get_current_backtrace (void)
        if (bt_str->len == 0) {
                g_string_free (bt_str, TRUE);
                bt_str = NULL;
-       } else {
-               g_string_insert (bt_str, 0, "\t   at ");
        }
 
        return bt_str;
@@ -681,21 +745,78 @@ camel_pointer_tracker_dump (void)
 /**
  * camel_debug_get_backtrace:
  *
- * Gets current backtrace leading to this function call.
+ * Gets current backtrace leading to this function call and demangles it.
  *
  * Returns: Current backtrace, or %NULL, if cannot determine it.
  *
  * Note: Getting backtraces only works if the library was
  * configured with --enable-backtraces.
  *
+ * See also camel_debug_get_raw_backtrace()
+ *
  * Since: 3.12
  **/
 GString *
 camel_debug_get_backtrace (void)
+{
+       GString *bt;
+
+       bt = get_current_backtrace ();
+
+       if (!bt)
+               return NULL;
+
+       demangle_bt (bt);
+
+       return bt;
+}
+
+/**
+ * camel_debug_get_raw_backtrace:
+ *
+ * Gets current raw backtrace leading to this function call.
+ * This is quicker than camel_debug_get_backtrace(), because it
+ * doesn't demangle the backtrace. To demangle it (replace addresses
+ * with actual function calls and eventually line numbers, if
+ * available) call camel_debug_demangle_backtrace().
+ *
+ * Returns: Current raw backtrace, or %NULL, if cannot determine it.
+ *
+ * Note: Getting backtraces only works if the library was
+ * configured with --enable-backtraces.
+ *
+ * See also camel_debug_get_backtrace()
+ *
+ * Since: 3.30
+ **/
+GString *
+camel_debug_get_raw_backtrace (void)
 {
        return get_current_backtrace ();
 }
 
+/**
+ * camel_debug_demangle_backtrace:
+ * @bt: (inout) (nullable): a #GString with a raw backtrace, or %NULL
+ *
+ * Demangles @bt, possibly got from camel_debug_get_raw_backtrace(), by
+ * replacing addresses with actual function calls and eventually line numbers, if
+ * available. It modifies lines of @bt, but skips those it cannot parse.
+ *
+ * Note: Getting backtraces only works if the library was
+ * configured with --enable-backtraces.
+ *
+ * See also camel_debug_get_raw_backtrace()
+ *
+ * Since: 3.30
+ **/
+void
+camel_debug_demangle_backtrace (GString *bt)
+{
+       if (bt)
+               demangle_bt (bt);
+}
+
 G_LOCK_DEFINE_STATIC (ref_unref_backtraces);
 static GQueue *ref_unref_backtraces = NULL;
 static guint total_ref_unref_backtraces = 0;
diff --git a/src/camel/camel-debug.h b/src/camel/camel-debug.h
index 62163e383..416a84146 100644
--- a/src/camel/camel-debug.h
+++ b/src/camel/camel-debug.h
@@ -147,6 +147,8 @@ void                camel_pointer_tracker_untrack   (gpointer ptr);
 void           camel_pointer_tracker_dump      (void);
 
 GString *      camel_debug_get_backtrace       (void);
+GString *      camel_debug_get_raw_backtrace   (void);
+void           camel_debug_demangle_backtrace  (GString *bt);
 
 void           camel_debug_ref_unref_push_backtrace
                                                (const GString *backtrace,