Reorganize iterate_over_labels

I noticed that iterate_over_labels was using a static variable as a
recursion variable, which isn't a safe thing to do since it will only be
initialized once.  While fixing that, I also reorganized the function
quite a bit.

* dwflpp.cxx (dwflpp::iterate_over_labels): Take the current function as
  a parameter instead of using a static local.  Rewrite some of the code
  as well to try to make it more obvious.
* tapsets.cxx (add_label_name): Remove in favor of query_label.
  (query_label): New, to check decl_file and fix probe listing.
  (query_srcfile_label, query_cu): Adjust to iterate_over_labels change
  and start using query_label as the callback.

3 files changed, 80 insertions, 71 deletions

diff --git a/dwflpp.cxx b/dwflpp.cxx
index 9ec7a7de..7e9894e1 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -918,18 +918,18 @@ dwflpp::iterate_over_srcfile_lines (char const * srcfile,
 
 void
 dwflpp::iterate_over_labels (Dwarf_Die *begin_die,
-                             const char *sym,
-                             const char *symfunction,
-                             void *data,
+                             const string& sym,
+                             const string& symfunction,
+                             dwarf_query *q,
                              void (* callback)(const string &,
                                                const char *,
+                                               const char *,
                                                int,
                                                Dwarf_Die *,
                                                Dwarf_Addr,
-                                               dwarf_query *))
+                                               dwarf_query *),
+                             const string& current_function)
 {
-  dwarf_query * q __attribute__ ((unused)) = static_cast<dwarf_query *>(data) ;
-
   get_module_dwarf();
 
   Dwarf_Die die;
@@ -937,63 +937,54 @@ dwflpp::iterate_over_labels (Dwarf_Die *begin_die,
   if (res != 0)
     return;  // die without children, bail out.
 
-  static string function_name = dwarf_diename (begin_die);
+  bool function_match =
+    (current_function == symfunction
+     || (name_has_wildcard(symfunction)
+         && function_name_matches_pattern (current_function, symfunction)));
+
   do
     {
       int tag = dwarf_tag(&die);
       const char *name = dwarf_diename (&die);
+      bool subfunction = false;
+
       switch (tag)
         {
         case DW_TAG_label:
-          if (name)
-            break;
-          else
-            continue; // Cannot handle unnamed label.
+          if (function_match && name &&
+              (name == sym
+               || (name_has_wildcard(sym)
+                   && function_name_matches_pattern (name, sym))))
+            {
+              // Get the file/line number for this label
+              int dline;
+              const char *file = dwarf_decl_file (&die);
+              dwarf_decl_line (&die, &dline);
+
+              // Don't try to be smart. Just drop no addr labels.
+              Dwarf_Addr stmt_addr;
+              if (dwarf_lowpc (&die, &stmt_addr) == 0)
+                {
+                  Dwarf_Die *scopes;
+                  int nscopes = dwarf_getscopes_die (&die, &scopes);
+                  if (nscopes > 1)
+                    callback(current_function, name, file, dline,
+                             &scopes[1], stmt_addr, q);
+                }
+            }
           break;
+
         case DW_TAG_subprogram:
-          if (!dwarf_hasattr(&die, DW_AT_declaration) && name)
-            function_name = name;
-          else
-            continue;
+          if (dwarf_hasattr(&die, DW_AT_declaration) || !name)
+            break;
         case DW_TAG_inlined_subroutine:
-            if (name)
-              function_name = name;
+          if (name)
+            subfunction = true;
         default:
           if (dwarf_haschildren (&die))
-            iterate_over_labels (&die, sym, symfunction, q, callback);
-          continue;
-        }
-
-      if (strcmp(function_name.c_str(), symfunction) == 0
-          || (name_has_wildcard(symfunction)
-              && function_name_matches (symfunction)))
-        {
-        }
-      else
-        continue;
-      if (strcmp(name, sym) == 0
-          || (name_has_wildcard(sym)
-              && function_name_matches_pattern (name, sym)))
-        {
-          const char *file = dwarf_decl_file (&die);
-
-          // Get the line number for this label
-          int dline;
-          dwarf_decl_line (&die, &dline);
-
-          Dwarf_Addr stmt_addr;
-          if (dwarf_lowpc (&die, &stmt_addr) != 0)
-            continue; // Don't try to be smart. Just drop no addr labels.
-
-          Dwarf_Die *scopes;
-          int nscopes = 0;
-          nscopes = dwarf_getscopes_die (&die, &scopes);
-          if (nscopes > 1)
-            {
-              callback(function_name.c_str(), file,
-                       dline, &scopes[1], stmt_addr, q);
-              add_label_name(q, name);
-            }
+            iterate_over_labels (&die, sym, symfunction, q, callback,
+                                 subfunction ? name : current_function);
+          break;
         }
     }
   while (dwarf_siblingof (&die, &die) == 0);
diff --git a/dwflpp.h b/dwflpp.h
index 1c7c9215..073b9bfc 100644
--- a/dwflpp.h
+++ b/dwflpp.h
@@ -78,7 +78,6 @@ typedef std::vector<inline_instance_info> inline_instance_map_t;
 /* XXX FIXME functions that dwflpp needs from tapsets.cxx */
 func_info_map_t *get_filtered_functions(dwarf_query *q);
 inline_instance_map_t *get_filtered_inlines(dwarf_query *q);
-void add_label_name(dwarf_query *q, const char *name);
 
 
 struct
@@ -225,15 +224,17 @@ struct dwflpp
                                    void *data);
 
   void iterate_over_labels (Dwarf_Die *begin_die,
-                            const char *sym,
-                            const char *symfunction,
-                            void *data,
+                            const std::string& sym,
+                            const std::string& symfunction,
+                            dwarf_query *q,
                             void (* callback)(const std::string &,
                                               const char *,
+                                              const char *,
                                               int,
                                               Dwarf_Die *,
                                               Dwarf_Addr,
-                                              dwarf_query *));
+                                              dwarf_query *),
+                            const std::string& current_function);
 
   void collect_srcfiles_matching (std::string const & pattern,
                                   std::set<std::string> & filtered_srcfiles);
diff --git a/tapsets.cxx b/tapsets.cxx
index 9f21bb20..9651426e 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -714,16 +714,6 @@ get_filtered_inlines(dwarf_query *q)
 
 
 void
-add_label_name(dwarf_query *q, const char *name)
-{
-  // this is a kludge to let the listing mode show labels to the user
-  if (q->sess.listing_mode)
-    q->results.back()->locations[0]->components.push_back
-      (new probe_point::component(TOK_LABEL, new literal_string (name)));
-}
-
-
-void
 dwarf_query::query_module_dwarf()
 {
   if (has_function_num || has_statement_num)
@@ -1114,6 +1104,33 @@ query_statement (string const & func,
 }
 
 static void
+query_label (string const & func,
+             char const * label,
+             char const * file,
+             int line,
+             Dwarf_Die *scope_die,
+             Dwarf_Addr stmt_addr,
+             dwarf_query * q)
+{
+  size_t i = q->results.size();
+
+  // weed out functions whose decl_file isn't one of
+  // the source files that we actually care about
+  if ((q->has_statement_str || q->has_function_str) &&
+      q->spec_type != function_alone &&
+      q->filtered_srcfiles.count(file) == 0)
+    return;
+
+  query_statement(func, file, line, scope_die, stmt_addr, q);
+
+  // this is a kludge to let the listing mode show labels to the user
+  if (q->sess.listing_mode)
+    for (; i < q->results.size(); ++i)
+      q->results[i]->locations[0]->components.push_back
+        (new probe_point::component(TOK_LABEL, new literal_string (label)));
+}
+
+static void
 query_inline_instance_info (inline_instance_info & ii,
 			    dwarf_query * q)
 {
@@ -1184,8 +1201,8 @@ query_srcfile_label (const dwarf_line_t& line, void * arg)
   for (func_info_map_t::iterator i = q->filtered_functions.begin();
        i != q->filtered_functions.end(); ++i)
     if (q->dw.die_has_pc (i->die, addr))
-      q->dw.iterate_over_labels (&i->die, q->label_val.c_str(), q->function.c_str(),
-                                 q, query_statement);
+      q->dw.iterate_over_labels (&i->die, q->label_val, q->function,
+                                 q, query_label, i->name);
 }
 
 static void
@@ -1280,7 +1297,7 @@ query_dwarf_func (Dwarf_Die * func, base_query * bq)
   if ((q->has_statement_str || q->has_function_str) &&
       q->spec_type != function_alone &&
       q->filtered_srcfiles.count(dwarf_decl_file(func)?:"") == 0)
-        return DWARF_CB_OK;
+    return DWARF_CB_OK;
 
   try
     {
@@ -1468,8 +1485,8 @@ query_cu (Dwarf_Die * cudie, void * arg)
 	  if (q->has_label)
 	    {
 	      if (q->line[0] == 0)		// No line number specified
-                q->dw.iterate_over_labels (q->dw.cu, q->label_val.c_str(), q->function.c_str(),
-                                           q, query_statement);
+                q->dw.iterate_over_labels (q->dw.cu, q->label_val, q->function,
+                                           q, query_label, "");
 	      else
 		for (set<string>::const_iterator i = q->filtered_srcfiles.begin();
 		     i != q->filtered_srcfiles.end(); ++i)