Factor out duplicated code to setup user/module Dwfl from dwflpp/translate.

* setupdwfl.h: Add setup_dwfl_user() and is_user_module().
* setupdwfl.cxx: Likewise.
* dwflpp.cxx (setup_user): Use setup_dwfl_user().
* translate.cxx (emit_symbol_data): Likewise and is_user_module().
* tapsets.cxx (dwarf_cast_expanding_visitor::visit_cast_op):
  Use is_user_module().

5 files changed, 92 insertions, 74 deletions

diff --git a/dwflpp.cxx b/dwflpp.cxx
index cc882e5d..b8e39b69 100644
--- a/dwflpp.cxx
+++ b/dwflpp.cxx
@@ -354,54 +354,17 @@ dwflpp::setup_user(const vector<string>& modules, bool debuginfo_needed)
   if (! sess.module_cache)
     sess.module_cache = new module_cache ();
 
-  static const char *debuginfo_path_arr = "+:.debug:/usr/lib/debug:build";
-  static const char *debuginfo_env_arr = getenv("SYSTEMTAP_DEBUGINFO_PATH");
-  // NB: kernel_build_tree doesn't enter into this, as it's for
-  // kernel-side modules only.
-  static const char *debuginfo_path = (debuginfo_env_arr ?: debuginfo_path_arr);
-
-  static const Dwfl_Callbacks user_callbacks =
-    {
-      NULL, /* dwfl_linux_kernel_find_elf, */
-      dwfl_standard_find_debuginfo,
-      dwfl_offline_section_address,
-      (char **) & debuginfo_path
-    };
-
-  dwfl = dwfl_begin (&user_callbacks);
-  if (!dwfl)
-    throw semantic_error ("cannot open dwfl");
-  dwfl_report_begin (dwfl);
-
-  vector<string>::const_iterator it;
-  for (it = modules.begin(); it != modules.end(); ++it)
-    {
-      // XXX: should support buildid-based naming
-
-      const string& module_name = *it;
-      Dwfl_Module *mod = dwfl_report_offline (dwfl,
-                                    module_name.c_str(),
-                                    module_name.c_str(),
-                                    -1);
-
-      if (debuginfo_needed)
-        dwfl_assert (string("missing process ") +
-                     module_name +
-                     string(" ") +
-                     sess.architecture +
-                     string(" debuginfo"),
-                     mod);
-    }
-
-  // NB: the result of an _offline call is the assignment of
-  // virtualized addresses to relocatable objects such as
-  // modules.  These have to be converted to real addresses at
-  // run time.  See the dwarf_derived_probe ctor and its caller.
-
-  dwfl_assert ("dwfl_report_end", dwfl_report_end(dwfl, NULL, NULL));
+  vector<string>::const_iterator it = modules.begin();
+  dwfl = setup_dwfl_user(it, modules.end(), debuginfo_needed);
+  if (debuginfo_needed && it != modules.end())
+    dwfl_assert (string("missing process ") +
+		 *it +
+		 string(" ") +
+		 sess.architecture +
+		 string(" debuginfo"),
+		 dwfl);
 }
 
-
 void
 dwflpp::iterate_over_modules(int (* callback)(Dwfl_Module *, void **,
                                               const char *, Dwarf_Addr,
diff --git a/setupdwfl.cxx b/setupdwfl.cxx
index 49667152..33d481ef 100644
--- a/setupdwfl.cxx
+++ b/setupdwfl.cxx
@@ -25,6 +25,12 @@ static const char *debuginfo_path_arr = "+:.debug:/usr/lib/debug:build";
 static const char *debuginfo_env_arr = getenv("SYSTEMTAP_DEBUGINFO_PATH");
 static const char *debuginfo_path = (debuginfo_env_arr ?: debuginfo_path_arr);
 
+// NB: kernel_build_tree doesn't enter into this, as it's for
+// kernel-side modules only.
+static const char *debuginfo_usr_path_arr = "+:.debug:/usr/lib/debug";
+static const char *debuginfo_usr_path = (debuginfo_env_arr
+					 ?: debuginfo_usr_path_arr);
+
 static const Dwfl_Callbacks kernel_callbacks =
   {
     dwfl_linux_kernel_find_elf,
@@ -33,6 +39,15 @@ static const Dwfl_Callbacks kernel_callbacks =
     (char **) & debuginfo_path
   };
 
+static const Dwfl_Callbacks user_callbacks =
+  {
+    NULL,
+    dwfl_standard_find_debuginfo,
+    NULL, /* ET_REL not supported for user space, only ET_EXEC and ET_DYN.
+	     dwfl_offline_section_address, */
+    (char **) & debuginfo_usr_path
+  };
+
 using namespace std;
 
 // Setup in setup_dwfl_kernel(), for use in setup_dwfl_report_kernel_p().
@@ -191,3 +206,53 @@ setup_dwfl_kernel(const std::set<std::string> &names,
   offline_search_names = names;
   return setup_dwfl_kernel(found, s);
 }
+
+Dwfl*
+setup_dwfl_user(const std::string &name)
+{
+  Dwfl *dwfl = dwfl_begin (&user_callbacks);
+  dwfl_assert("dwfl_begin", dwfl);
+  dwfl_report_begin (dwfl);
+
+  // XXX: should support buildid-based naming
+  const char *cname = name.c_str();
+  Dwfl_Module *mod = dwfl_report_offline (dwfl, cname, cname, -1);
+  dwfl_assert ("dwfl_report_end", dwfl_report_end(dwfl, NULL, NULL));
+  if (! mod)
+    {
+      dwfl_end(dwfl);
+      dwfl = NULL;
+    }
+  return dwfl;
+}
+
+Dwfl*
+setup_dwfl_user(std::vector<std::string>::const_iterator &begin,
+		const std::vector<std::string>::const_iterator &end,
+		bool all_needed)
+{
+  Dwfl *dwfl = dwfl_begin (&user_callbacks);
+  dwfl_assert("dwfl_begin", dwfl);
+  dwfl_report_begin (dwfl);
+
+  // XXX: should support buildid-based naming
+  while (begin != end && dwfl != NULL)
+    {
+      const char *cname = (*begin).c_str();
+      Dwfl_Module *mod = dwfl_report_offline (dwfl, cname, cname, -1);
+      if (! mod && all_needed)
+	{
+	  dwfl_end(dwfl);
+	  dwfl = NULL;
+	}
+      begin++;
+    }
+  if (dwfl)
+    dwfl_assert ("dwfl_report_end", dwfl_report_end(dwfl, NULL, NULL));
+  return dwfl;
+}
+
+bool is_user_module(const std::string &m)
+{
+  return m[0] == '/' && m.rfind(".ko", m.length() - 1) != m.length() - 3;
+}
diff --git a/setupdwfl.h b/setupdwfl.h
index 7884e4da..67a66397 100644
--- a/setupdwfl.h
+++ b/setupdwfl.h
@@ -14,6 +14,7 @@
 
 #include <set>
 #include <string>
+#include <vector>
 
 extern "C" {
 #include <elfutils/libdwfl.h>
@@ -25,4 +26,13 @@ Dwfl *setup_dwfl_kernel(const std::string &name,
 Dwfl *setup_dwfl_kernel(const std::set<std::string> &names,
 			unsigned *found,
 			systemtap_session &s);
+
+Dwfl* setup_dwfl_user(const std::string &name);
+Dwfl* setup_dwfl_user(std::vector<std::string>::const_iterator &begin,
+		      const std::vector<std::string>::const_iterator &end,
+		      bool all_needed);
+
+// user-space files must be full paths and not end in .ko
+bool is_user_module(const std::string &m);
+
 #endif
diff --git a/tapsets.cxx b/tapsets.cxx
index 4a8432f7..bedb267a 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -21,6 +21,7 @@
 #include "auto_free.h"
 #include "hash.h"
 #include "dwflpp.h"
+#include "setupdwfl.h"
 
 #include <cstdlib>
 #include <algorithm>
@@ -2606,7 +2607,7 @@ void dwarf_cast_expanding_visitor::visit_cast_op (cast_op* e)
       dwflpp* dw;
       try
 	{
-	  if (module.find('/') == string::npos)
+	  if (! is_user_module (module))
 	    {
 	      // kernel or kernel module target
 	      dw = db.get_kern_dw(s, module);
diff --git a/translate.cxx b/translate.cxx
index 1bb6252f..0f53dc78 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -4957,8 +4957,9 @@ emit_symbol_data (systemtap_session& s)
        it++)
     {
       string foo = *it;
-      if (foo[0] != '/') /* Omit user-space, since we're only using this for
-                            kernel space offline searches. */
+      if (! is_user_module (foo)) /* Omit user-space, since we're only
+				     using this for kernel space
+				     offline searches. */
         offline_search_modules.insert (foo);
     }
   Dwfl *dwfl = setup_dwfl_kernel (offline_search_modules, &count, s);
@@ -4978,37 +4979,15 @@ emit_symbol_data (systemtap_session& s)
 
 
   // ---- step 2: process any user modules (files) listed
-  // XXX: see dwflpp::setup_user.
-
-  // XXX: copied from tapsets.cxx dwflpp::, sadly
-  static const char *debuginfo_path_arr = "+:.debug:/usr/lib/debug:build";
-  static const char *debuginfo_env_arr = getenv("SYSTEMTAP_DEBUGINFO_PATH");
-  static const char *debuginfo_path = (debuginfo_env_arr ?: debuginfo_path_arr);
-
-  static const Dwfl_Callbacks user_callbacks =
-    {
-      NULL, /* dwfl_linux_kernel_find_elf, */
-      dwfl_standard_find_debuginfo,
-      NULL, /* ET_REL not supported for user space, only ET_EXEC and ET_DYN.
-              dwfl_offline_section_address, */
-      (char **) & debuginfo_path
-    };
-
   for (std::set<std::string>::iterator it = s.unwindsym_modules.begin();
        it != s.unwindsym_modules.end();
        it++)
     {
       string modname = *it;
       assert (modname.length() != 0);
-      if (modname[0] != '/') continue; // user-space files must be full paths
-      Dwfl *dwfl = dwfl_begin (&user_callbacks);
-      if (!dwfl)
-        throw semantic_error ("cannot create dwfl for " + modname);
-
-      dwfl_report_begin (dwfl);
-      Dwfl_Module* mod = dwfl_report_offline (dwfl, modname.c_str(), modname.c_str(), -1);
-      dwfl_report_end (dwfl, NULL, NULL);
-      if (mod != 0) // tolerate missing data; will warn below
+      if (! is_user_module (modname)) continue;
+      Dwfl *dwfl = setup_dwfl_user (modname);
+      if (dwfl != NULL) // tolerate missing data; will warn below
         {
           ptrdiff_t off = 0;
           do