From: Josh Stone <jistone@redhat.com>
Date: Thu, 12 Apr 2012 19:51:24 +0000 (-0700)
Subject: sdt_query: initialize probe_type/loc as unknown.
X-Git-Tag: release-1.8~173
X-Git-Url: https://sourceware.org/git/?a=commitdiff_plain;h=d61ea6024b0a465f786b11122c5bc73a11f84a93;p=systemtap.git

sdt_query: initialize probe_type/loc as unknown.

The fields, probe_type and probe_loc, are meaningless to start, and are
later set as the queried module is examined.  Commit 74fe61bc tried to
make sure that all POD types in this class are initialized, but these
two were essentially self-assigned.  Gcc misses this uninitialized use,
but clang caught it:

  CXX    stap-tapsets.o
../tapsets.cxx:6058:38: error: field is uninitialized when used here [-Werror,-Wuninitialized]
  base_query(dw, params), probe_type(probe_type), probe_loc(probe_loc), base_probe(base_probe),
                                     ^
../tapsets.cxx:6058:61: error: field is uninitialized when used here [-Werror,-Wuninitialized]
  base_query(dw, params), probe_type(probe_type), probe_loc(probe_loc), base_probe(base_probe),
                                                            ^

Values for "unknown" are now added to these enum types to initialize
with, and dealt with where needed.
---

diff --git a/sdt_types.h b/sdt_types.h
index 461da4c06..74ef02a38 100644
--- a/sdt_types.h
+++ b/sdt_types.h
@@ -18,7 +18,8 @@ typedef enum
     kprobe1_type = KPROBE1_TYPE,
     uprobe2_type = UPROBE2_TYPE,
     kprobe2_type = KPROBE2_TYPE,
-    uprobe3_type = UPROBE3_TYPE
+    uprobe3_type = UPROBE3_TYPE,
+    unknown_probe_type = -1,
   } stap_sdt_probe_type;
 
 typedef struct
diff --git a/tapsets.cxx b/tapsets.cxx
index 97cedc0c7..b998805a5 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -6009,7 +6009,7 @@ struct sdt_query : public base_query
 
 private:
   stap_sdt_probe_type probe_type;
-  enum {probe_section=0, note_section=1} probe_loc;
+  enum { probe_section=0, note_section=1, unknown_section=-1 } probe_loc;
   probe * base_probe;
   probe_point * base_loc;
   literal_map_t const & params;
@@ -6055,7 +6055,8 @@ private:
 sdt_query::sdt_query(probe * base_probe, probe_point * base_loc,
                      dwflpp & dw, literal_map_t const & params,
                      vector<derived_probe *> & results, const string user_lib):
-  base_query(dw, params), probe_type(probe_type), probe_loc(probe_loc), base_probe(base_probe),
+  base_query(dw, params), probe_type(unknown_probe_type),
+  probe_loc(unknown_section), base_probe(base_probe),
   base_loc(base_loc), params(params), results(results), user_lib(user_lib),
   probe_scn_offset(0), probe_scn_addr(0), arg_count(0), base(0), pc(0),
   semaphore(0)
@@ -6107,6 +6108,9 @@ sdt_query::handle_probe_entry()
 	case kprobe2_type:
 	  clog << "kprobe2" << endl;
 	  break;
+	default:
+	  clog << "unknown!" << endl;
+	  break;
 	}
     }
 
@@ -6218,7 +6222,7 @@ sdt_query::handle_query_module()
 	base = 0;
       dw.iterate_over_notes ((void*) this, &sdt_query::setup_note_probe_entry_callback);
     }
-  else
+  else if (probe_loc == probe_section)
     iterate_over_probe_entries ();
 }