Merge commit 'origin/master' into pr6429-comp-unwindsyms

* commit 'origin/master':
  Fix assignment optimization expected results.
  PR6538: more testsuite tweaks for read-only warnings
  PR6538: more tapset fixes
  PR6538: explain why absentstats.stp logs will contain warnings
  PR6538: fix treatment of initialized globals
  Use pointer_arg to fetch arguments for syscall.utime and compat_utime.
  Optimize compound and binary expression assignments.
  Check new (sub) functions of _struct_utimbuf_* and _struct_compat_utimbuf_*.
  PR6538: tapset changes
  PR6538: testsuite changes
  PR5001: fix test suite collateral damage
  PR6538: warn about read-only variables
  Add some scripts and descriptions to the systemtap.examples.
  PR5001: Remove _stp_ctime and always use ctime.
  Use tr1/unordered_map instead of the deprecated ext/hash_map.
  PR6524: ctime() on bad values hangs system.
  Optimize away assignments in other contexts.
  Optimize away assignments in other contexts.
  dummy commit for testing systemtap-cvs notification
  Remove sa_restorer initialization.

1 files changed, 35 insertions, 3 deletions

diff --git a/staptree.cxx b/staptree.cxx
index 02a6c8dc..347d799f 100644
--- a/staptree.cxx
+++ b/staptree.cxx
@@ -1713,6 +1713,15 @@ varuse_collecting_visitor::visit_symbol (symbol *e)
   if (e->referent == 0)
     throw semantic_error ("symbol without referent", e->tok);
 
+  // We could handle initialized globals by marking them as "written".
+  // However, this current visitor may be called for a function or
+  // probe body, from the point of view of which this global is
+  // already initialized, so not written.
+  /*
+  if (e->referent->init)
+    written.insert (e->referent);
+  */
+
   if (current_lvalue == e || current_lrvalue == e)
     {
       written.insert (e->referent);
@@ -1789,10 +1798,19 @@ varuse_collecting_visitor::visit_post_crement (post_crement *e)
 void
 varuse_collecting_visitor::visit_foreach_loop (foreach_loop* s)
 {
-  functioncall_traversing_visitor::visit_foreach_loop (s);
+  // NB: we duplicate so don't bother call
+  // functioncall_traversing_visitor::visit_foreach_loop (s);
+
+  symbol *array = NULL;  
+  hist_op *hist = NULL;
+  classify_indexable (s->base, array, hist);
+  if (array)
+    array->visit(this);
+  else
+    hist->visit(this);
+
   // If the collection is sorted, imply a "write" access to the
-  // array in addition to the "read" one already noted in the
-  // base class call above.
+  // array in addition to the "read" one already noted above.
   if (s->sort_direction)
     {
       symbol *array = NULL;  
@@ -1801,6 +1819,20 @@ varuse_collecting_visitor::visit_foreach_loop (foreach_loop* s)
       if (array) this->written.insert (array->referent);
       // XXX: Can hist_op iterations be sorted?
     }
+
+  // NB: don't forget to visit the index expressions, which are lvalues.
+  for (unsigned i=0; i<s->indexes.size(); i++)
+    {
+      expression* last_lvalue = current_lvalue;
+      current_lvalue = s->indexes[i]; // leave a mark for ::visit_symbol
+      s->indexes[i]->visit (this);
+      current_lvalue = last_lvalue;
+    }
+
+  if (s->limit)
+    s->limit->visit (this);
+
+  s->block->visit (this);
 }