template-ify iterate_over_modules()

diff --git a/dwflpp.cxx b/dwflpp.cxx
index 2730096fcf1233fd9d5298ba2bef4ddf86f44a3c..3b6585f5d30b21696b05053d5027b696d36aec7b 100644 (file)
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -390,11 +390,13 @@ dwflpp::setup_user(const vector<string>& modules, bool debuginfo_needed)
                            dwfl_ptr.get()->dwfl);
 }
 
-void
-dwflpp::iterate_over_modules(int (* callback)(Dwfl_Module *, void **,
-                                              const char *, Dwarf_Addr,
-                                              void *),
-                             void *data)
+template<> void
+dwflpp::iterate_over_modules<void>(int (*callback)(Dwfl_Module*,
+                                                   void**,
+                                                   const char*,
+                                                   Dwarf_Addr,
+                                                   void*),
+                                   void *data)
 {
   dwfl_getmodules (dwfl_ptr.get()->dwfl, callback, data, 0);
 

diff --git a/dwflpp.h b/dwflpp.h
index 839cfb79cbc29141b6cedf6e7f10416a2113920a..8e5b6685e567d348efeeb042d644a8428b563a6b 100644 (file)
--- a/dwflpp.h
+++ b/dwflpp.h
@@ -203,10 +203,28 @@ struct dwflpp
   bool function_name_matches(const std::string& pattern);
   bool function_scope_matches(const std::vector<std::string>& scopes);
 
-  void iterate_over_modules(int (* callback)(Dwfl_Module *, void **,
-                                             const char *, Dwarf_Addr,
-                                             void *),
-                            void *data);
+  template<typename T>
+  void iterate_over_modules(int (* callback)(Dwfl_Module*,
+                                             void**,
+                                             const char*,
+                                             Dwarf_Addr,
+                                             T*),
+                            T *data)
+    {
+      /* We're using templates here to enforce type-safety between the data arg
+       * we're requested to pass to callback, and the data arg that the callback
+       * actually takes. Rather than putting the implementation here, we simply
+       * call the <void> specialization, which does the real work.
+       *    As a result, we need to cast the data arg in the callback signature
+       * and the one passed to void* (which is what elfutils also works with).
+       * */
+      iterate_over_modules<void>((int (*)(Dwfl_Module*,
+                                          void**,
+                                          const char*,
+                                          Dwarf_Addr,
+                                          void *))callback,
+                                  (void*)data);
+    }
 
   void iterate_over_cus (int (*callback)(Dwarf_Die * die, void * arg),
                          void * data, bool want_types);
@@ -379,6 +397,8 @@ private:
   static int global_alias_caching_callback(Dwarf_Die *die, bool has_inner_types,
                                            const std::string& prefix, void *arg);
   static int global_alias_caching_callback_cus(Dwarf_Die *die, void *arg);
+
+
   static int iterate_over_globals (Dwarf_Die *,
                                    int (* callback)(Dwarf_Die *, bool,
                                                     const std::string&, void *),
@@ -475,6 +495,14 @@ public:
   Dwarf_Addr pr15123_retry_addr (Dwarf_Addr pc, Dwarf_Die* var);
 };
 
+template<> void
+dwflpp::iterate_over_modules<void>(int (*callback)(Dwfl_Module*,
+                                                   void**,
+                                                   const char*,
+                                                   Dwarf_Addr,
+                                                   void*),
+                                   void *data);
+
 #endif // DWFLPP_H
 
 /* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */

diff --git a/tapsets.cxx b/tapsets.cxx
index 31c4d6f7eba08485e1f118883f77b3709efa743c..80047e32904ce1b103c914762b116732b0a20c7c 100644 (file)
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -2139,10 +2139,8 @@ query_module (Dwfl_Module *mod,
               void **,
              const char *name,
               Dwarf_Addr addr,
-             void *arg)
+             base_query *q)
 {
-  base_query *q = static_cast<base_query *>(arg);
-
   try
     {
       module_info* mi = q->sess.module_cache->cache[name];
@@ -4207,7 +4205,7 @@ void dwarf_cast_expanding_visitor::visit_cast_op (cast_op* e)
        }
 
       dwarf_cast_query q (*dw, module, *e, lvalue, userspace_p, result);
-      dw->iterate_over_modules(&query_module, &q);
+      dw->iterate_over_modules<base_query>(&query_module, &q);
     }
 
   if (!result)
@@ -4378,7 +4376,7 @@ dwarf_atvar_expanding_visitor::visit_atvar_op (atvar_op* e)
         }
 
       dwarf_atvar_query q (*dw, module, *e, userspace_p, lvalue, result, tick);
-      dw->iterate_over_modules(&query_module, &q);
+      dw->iterate_over_modules<base_query>(&query_module, &q);
 
       if (result)
         {
@@ -6532,7 +6530,7 @@ sdt_query::handle_probe_entry()
   // V1 probes always need dwarf info
   // V2+ probes need dwarf info in case of a variable reference
   if (have_debuginfo_uprobe(need_debug_info))
-    dw.iterate_over_modules(&query_module, &q);
+    dw.iterate_over_modules<base_query>(&query_module, &q);
 
   // For V2+ probes, if variable references weren't used or failed (PR14369),
   // then try with the more direct approach.  Unresolved $vars might still
@@ -7426,7 +7424,7 @@ dwarf_builder::build(systemtap_session & sess,
   if (get_param(parameters, TOK_MARK, dummy_mark_name))
     {
       sdt_query sdtq(base, location, *dw, filled_parameters, finished_results, user_lib);
-      dw->iterate_over_modules(&query_module, &sdtq);
+      dw->iterate_over_modules<base_query>(&query_module, &sdtq);
 
       // We need to update modules_seen with the modules we've visited
       modules_seen.insert(sdtq.visited_modules.begin(),
@@ -7475,7 +7473,7 @@ dwarf_builder::build(systemtap_session & sess,
       return;
     }
 
-  dw->iterate_over_modules(&query_module, &q);
+  dw->iterate_over_modules<base_query>(&query_module, &q);
 
   // We need to update modules_seen with the modules we've visited
   modules_seen.insert(q.visited_modules.begin(),
@@ -10748,7 +10746,7 @@ tracepoint_builder::build(systemtap_session& s,
 
   tracepoint_query q(*dw, tracepoint, base, location, finished_results);
   unsigned results_pre = finished_results.size();
-  dw->iterate_over_modules(&query_module, &q);
+  dw->iterate_over_modules<base_query>(&query_module, &q);
   unsigned results_post = finished_results.size();
 
   // Did we fail to find a match? Let's suggest something!

diff --git a/translate.cxx b/translate.cxx
index 7ef4c86e0a17c71294470f180a221eb9b984ef18..1214dd0f9e12dbee15891e6affdf90f9c863d40c 100644 (file)
--- a/translate.cxx
+++ b/translate.cxx
@@ -6376,9 +6376,9 @@ query_module (Dwfl_Module *mod,
               void **,
               const char *,
               Dwarf_Addr,
-              void *arg)
+              struct dwflpp *dwflpp)
 {
-  ((struct dwflpp*)arg)->focus_on_module(mod, NULL);
+  dwflpp->focus_on_module(mod, NULL);
   return DWARF_CB_OK;
 }
 
@@ -6397,7 +6397,7 @@ add_unwindsym_ldd (systemtap_session &s)
       if (! is_user_module (modname)) continue;
 
       struct dwflpp *mod_dwflpp = new dwflpp(s, modname, false);
-      mod_dwflpp->iterate_over_modules (&query_module, mod_dwflpp);
+      mod_dwflpp->iterate_over_modules(&query_module, mod_dwflpp);
       if (mod_dwflpp->module) // existing binary
         {
           assert (mod_dwflpp->module_name != "");