Unify no-component assertions on target variables

There are several tapsets that can't deal with component dereferences on
their target variables, and they all check-and-throw in the same way.
This refactors the checks into a target_symbol member.

* staptree.cxx (target_symbol::assert_no_components): New.
* tapsets.cxx (tracepoint_var_expanding_visitor::visit_target_symbol_arg,
  tracepoint_var_expanding_visitor::visit_target_symbol_context): Use
  the new assertion function to check for no components.
* tapset-mark.cxx (mark_var_expanding_visitor::visit_target_symbol_arg,
  mark_var_expanding_visitor::visit_target_symbol_context): Ditto.
* tapset-perfmon.cxx (perfmon_var_expanding_visitor::visit_target_symbol): Ditto.
* tapset-procfs.cxx (procfs_var_expanding_visitor::visit_target_symbol): Ditto.
* tapset-utrace.cxx (utrace_var_expanding_visitor::visit_target_symbol_arg,
  utrace_var_expanding_visitor::visit_target_symbol_context): Ditto.

7 files changed, 34 insertions, 131 deletions

diff --git a/staptree.cxx b/staptree.cxx
index 1231f74d..321650eb 100644
--- a/staptree.cxx
+++ b/staptree.cxx
@@ -186,6 +186,30 @@ operator << (ostream& o, const exp_type& e)
 }
 
 
+void
+target_symbol::assert_no_components(const std::string& tapset)
+{
+  if (components.empty())
+    return;
+
+  switch (components[0].type)
+    {
+    case target_symbol::comp_literal_array_index:
+      throw semantic_error(tapset + " variable '" + base_name +
+                           "' may not be used as array",
+                           components[0].tok);
+    case target_symbol::comp_struct_member:
+      throw semantic_error(tapset + " variable '" + base_name +
+                           "' may not be used as a structure",
+                           components[0].tok);
+    default:
+      throw semantic_error ("invalid use of " + tapset +
+                            " variable '" + base_name + "'",
+                            components[0].tok);
+    }
+}
+
+
 // ------------------------------------------------------------------------
 // parse tree printing
 
diff --git a/staptree.h b/staptree.h
index 70746f31..9ade2a42 100644
--- a/staptree.h
+++ b/staptree.h
@@ -252,6 +252,7 @@ struct target_symbol: public symbol
   target_symbol(): addressof(false), saved_conversion_error (0) {}
   void print (std::ostream& o) const;
   void visit (visitor* u);
+  void assert_no_components(const std::string& tapset);
 };
 
 std::ostream& operator << (std::ostream& o, const target_symbol::component& c);
diff --git a/tapset-mark.cxx b/tapset-mark.cxx
index fcde9ed5..59334729 100644
--- a/tapset-mark.cxx
+++ b/tapset-mark.cxx
@@ -103,23 +103,7 @@ mark_var_expanding_visitor::visit_target_symbol_arg (target_symbol* e)
   if (is_active_lvalue (e))
     throw semantic_error("write to marker parameter not permitted", e->tok);
 
-  if (e->components.size() > 0)
-    {
-      switch (e->components[0].type)
-	{
-	case target_symbol::comp_literal_array_index:
-	  throw semantic_error("marker argument may not be used as array",
-			       e->tok);
-	  break;
-	case target_symbol::comp_struct_member:
-	  throw semantic_error("marker argument may not be used as a structure",
-			       e->tok);
-	  break;
-	default:
-	  throw semantic_error ("invalid marker argument use", e->tok);
-	  break;
-	}
-    }
+  e->assert_no_components("marker");
 
   // Remember that we've seen a target variable.
   target_symbol_seen = true;
@@ -138,23 +122,7 @@ mark_var_expanding_visitor::visit_target_symbol_context (target_symbol* e)
   if (is_active_lvalue (e))
     throw semantic_error("write to marker '" + sname + "' not permitted", e->tok);
 
-  if (e->components.size() > 0)
-    {
-      switch (e->components[0].type)
-	{
-	case target_symbol::comp_literal_array_index:
-	  throw semantic_error("marker '" + sname + "' may not be used as array",
-			       e->tok);
-	  break;
-	case target_symbol::comp_struct_member:
-	  throw semantic_error("marker '" + sname + "' may not be used as a structure",
-			       e->tok);
-	  break;
-	default:
-	  throw semantic_error ("invalid marker '" + sname + "' use", e->tok);
-	  break;
-	}
-    }
+  e->assert_no_components("marker");
 
   if (e->base_name == "$format" || e->base_name == "$name") {
      string fname;
diff --git a/tapset-perfmon.cxx b/tapset-perfmon.cxx
index dfdc55e6..d524aa03 100644
--- a/tapset-perfmon.cxx
+++ b/tapset-perfmon.cxx
@@ -67,24 +67,7 @@ perfmon_var_expanding_visitor::visit_target_symbol (target_symbol *e)
   if (e->addressof)
     throw semantic_error("cannot take address of perfmon variable", e->tok);
 
-  if (e->components.size() > 0)
-    {
-      switch (e->components[0].type)
-        {
-        case target_symbol::comp_literal_array_index:
-          throw semantic_error("perfmon probe '$counter' variable may not be used as array",
-                               e->tok);
-          break;
-        case target_symbol::comp_struct_member:
-          throw semantic_error("perfmon probe '$counter' variable may not be used as a structure",
-                               e->tok);
-          break;
-        default:
-          throw semantic_error ("invalid use of perfmon probe '$counter' variable",
-                                e->tok);
-          break;
-        }
-    }
+  e->assert_no_components("perfmon");
 
   ec->code = "THIS->__retvalue = _pfm_pmd_x[" +
           lex_cast<string>(counter_number) + "].reg_num;";
diff --git a/tapset-procfs.cxx b/tapset-procfs.cxx
index 58bb0f0d..3302057c 100644
--- a/tapset-procfs.cxx
+++ b/tapset-procfs.cxx
@@ -358,24 +358,7 @@ procfs_var_expanding_visitor::visit_target_symbol (target_symbol* e)
     throw semantic_error ("invalid target symbol for procfs probe, $value expected",
                           e->tok);
 
-  if (e->components.size() > 0)
-    {
-      switch (e->components[0].type)
-        {
-        case target_symbol::comp_literal_array_index:
-          throw semantic_error("procfs target variable '$value' may not be used as array",
-                               e->tok);
-          break;
-        case target_symbol::comp_struct_member:
-          throw semantic_error("procfs target variable '$value' may not be used as a structure",
-                               e->tok);
-          break;
-        default:
-          throw semantic_error ("invalid use of procfs target variable '$value'",
-                                e->tok);
-          break;
-        }
-    }
+  e->assert_no_components("procfs");
 
   bool lvalue = is_active_lvalue(e);
   if (write_probe && lvalue)
diff --git a/tapset-utrace.cxx b/tapset-utrace.cxx
index 3befcbd5..87053f7d 100644
--- a/tapset-utrace.cxx
+++ b/tapset-utrace.cxx
@@ -455,24 +455,7 @@ utrace_var_expanding_visitor::visit_target_symbol_arg (target_symbol* e)
         string argnum_s = e->base_name.substr(4,e->base_name.length()-4);
         int argnum = lex_cast<int>(argnum_s);
 
-        if (e->components.size() > 0)
-         {
-           switch (e->components[0].type)
-     	    {
-	     case target_symbol::comp_literal_array_index:
-	       throw semantic_error("utrace target variable '$argN' may not be used as array",
-	   		            e->tok);
-	       break;
-	     case target_symbol::comp_struct_member:
-	       throw semantic_error("utrace target variable '$argN' may not be used as a structure",
-			            e->tok);
-	       break;
-  	     default:
-	       throw semantic_error ("invalid use of utrace target variable '$argN'",
-	  			     e->tok);
-	      break;
-	    }
-         }
+        e->assert_no_components("utrace");
 
         // FIXME: max argnument number should not be hardcoded.
         if (argnum < 1 || argnum > 6)
@@ -505,24 +488,7 @@ utrace_var_expanding_visitor::visit_target_symbol_context (target_symbol* e)
 {
   string sname = e->base_name;
 
-  if (e->components.size() > 0)
-    {
-      switch (e->components[0].type)
-	{
-	case target_symbol::comp_literal_array_index:
-	  throw semantic_error("utrace target variable '" + sname + "' may not be used as array",
-			       e->tok);
-	  break;
-	case target_symbol::comp_struct_member:
-	  throw semantic_error("utrace target variable '" + sname + "' may not be used as a structure",
-			       e->tok);
-	  break;
-	default:
-	  throw semantic_error ("invalid use of utrace target variable '" + sname + "'",
-				e->tok);
-	  break;
-	}
-    }
+  e->assert_no_components("utrace");
 
   bool lvalue = is_active_lvalue(e);
   if (lvalue)
diff --git a/tapsets.cxx b/tapsets.cxx
index 70edc7d8..537c33e7 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -5261,19 +5261,8 @@ tracepoint_var_expanding_visitor::visit_target_symbol_arg (target_symbol* e)
     }
 
   // make sure we're not dereferencing base types
-  if (!e->components.empty() && !arg->isptr)
-    switch (e->components[0].type)
-      {
-      case target_symbol::comp_literal_array_index:
-        throw semantic_error("tracepoint variable '" + e->base_name
-                             + "' may not be used as array", e->tok);
-      case target_symbol::comp_struct_member:
-        throw semantic_error("tracepoint variable '" + e->base_name
-                             + "' may not be used as a structure", e->tok);
-      default:
-        throw semantic_error("invalid use of tracepoint variable '"
-                             + e->base_name + "'", e->tok);
-      }
+  if (!arg->isptr)
+    e->assert_no_components("tracepoint");
 
   // we can only write to dereferenced fields, and only if guru mode is on
   bool lvalue = is_active_lvalue(e);
@@ -5393,18 +5382,7 @@ tracepoint_var_expanding_visitor::visit_target_symbol_context (target_symbol* e)
   if (is_active_lvalue (e))
     throw semantic_error("write to tracepoint '" + e->base_name + "' not permitted", e->tok);
 
-  if (!e->components.empty())
-    switch (e->components[0].type)
-      {
-      case target_symbol::comp_literal_array_index:
-        throw semantic_error("tracepoint '" + e->base_name + "' may not be used as array",
-                             e->tok);
-      case target_symbol::comp_struct_member:
-        throw semantic_error("tracepoint '" + e->base_name + "' may not be used as a structure",
-                             e->tok);
-      default:
-        throw semantic_error("invalid tracepoint '" + e->base_name + "' use", e->tok);
-      }
+  e->assert_no_components("tracepoint");
 
   if (e->base_name == "$$name")
     {