Add $name context variable support on marker probes

8 files changed, 112 insertions, 29 deletions

diff --git a/ChangeLog b/ChangeLog
index 09f661ae..cb5a6f4b 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,16 @@
+2008-09-09  Masami Hiramatsu  <mhiramat@redhat.com>
+
+	* stapprobes.5.in : Added a line for $name context variable.
+	* translate.cxx (c_unparser::emit_common_header): Add marker_name and
+	marker_format fields to context.
+	* tapsets.cxx (common_probe_entryfn_prologue) : Ditto.
+	(mark_derived_probe_group::emit_module_decls) : Ditto.
+	(mark_var_expanding_copy_visitor) : change visit_target_symbol_format
+	to visit_target_symbol_context.
+	(mark_var_expanding_copy_visitor::visit_target_symbol_context): handle
+	not only $format but also $name.
+	(mark_var_expanding_copy_visitor::visit_target_symbol): Ditto.
+
 2008-09-07  Frank Ch. Eigler  <fche@elastic.org>
 
 	* tapsets.cxx (build_blacklist): Add some x86 raw port-io spots.
diff --git a/stapprobes.5.in b/stapprobes.5.in
index 5281c40e..ecc6956c 100644
--- a/stapprobes.5.in
+++ b/stapprobes.5.in
@@ -520,6 +520,8 @@ and string parameters are passed in a type-safe manner.
 
 The marker format string associated with a marker is available in
 .BR $format .
+And also the marker name string is avalable in
+.BR $name .
 
 .SS PERFORMANCE MONITORING HARDWARE
 
diff --git a/tapset/ChangeLog b/tapset/ChangeLog
index 39b6b93b..d3117620 100644
--- a/tapset/ChangeLog
+++ b/tapset/ChangeLog
@@ -1,3 +1,7 @@
+2008-09-09  Masami Hiramatsu  <mhiramat@redhat.com>
+
+	* marker.stp : New file, including marker context variable accessors.
+
 2008-09-01  Frank Ch. Eigler  <fche@elastic.org>
 
 	PR4225 merge.
diff --git a/tapset/marker.stp b/tapset/marker.stp
new file mode 100644
index 00000000..593ffaea
--- /dev/null
+++ b/tapset/marker.stp
@@ -0,0 +1,22 @@
+//
+// kernel marker tapset
+//
+// This file is part of systemtap, and is free software.  You can
+// redistribute it and/or modify it under the terms of the GNU General
+// Public License (GPL); either version 2, or (at your option) any
+// later version.
+
+/* marker-only context accessors */
+
+
+function _mark_name_get:string () %{
+	strlcpy (THIS->__retvalue,
+		 (CONTEXT->marker_name)?CONTEXT->marker_name:"",
+		 MAXSTRINGLEN); /* pure */
+%}
+
+function _mark_format_get:string () %{
+	strlcpy (THIS->__retvalue,
+		 (CONTEXT->marker_format)?CONTEXT->marker_format:"",
+		 MAXSTRINGLEN); /* pure */
+%}
diff --git a/tapsets.cxx b/tapsets.cxx
index 64fa9d34..4774c0f6 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -221,6 +221,8 @@ common_probe_entryfn_prologue (translator_output* o, string statestr,
   // reset unwound address cache
   o->newline() << "c->pi = 0;";
   o->newline() << "c->regparm = 0;";
+  o->newline() << "c->marker_name = NULL;";
+  o->newline() << "c->marker_format = NULL;";
   o->newline() << "c->probe_point = 0;";
   if (! interruptible)
     o->newline() << "c->actionremaining = MAXACTION;";
@@ -7758,7 +7760,7 @@ struct mark_var_expanding_copy_visitor: public var_expanding_copy_visitor
 
   void visit_target_symbol (target_symbol* e);
   void visit_target_symbol_arg (target_symbol* e);
-  void visit_target_symbol_format (target_symbol* e);
+  void visit_target_symbol_context (target_symbol* e);
 };
 
 
@@ -7865,48 +7867,37 @@ mark_var_expanding_copy_visitor::visit_target_symbol_arg (target_symbol* e)
 
 
 void
-mark_var_expanding_copy_visitor::visit_target_symbol_format (target_symbol* e)
+mark_var_expanding_copy_visitor::visit_target_symbol_context (target_symbol* e)
 {
-  static bool function_synthesized = false;
+  string sname = e->base_name;
 
   if (is_active_lvalue (e))
-    throw semantic_error("write to marker format not permitted", e->tok);
+    throw semantic_error("write to marker '" + sname + "' not permitted", e->tok);
 
   if (e->components.size() > 0)
     {
       switch (e->components[0].first)
 	{
 	case target_symbol::comp_literal_array_index:
-	  throw semantic_error("marker format may not be used as array",
+	  throw semantic_error("marker '" + sname + "' may not be used as array",
 			       e->tok);
 	  break;
 	case target_symbol::comp_struct_member:
-	  throw semantic_error("marker format may not be used as a structure",
+	  throw semantic_error("marker '" + sname + "' may not be used as a structure",
 			       e->tok);
 	  break;
 	default:
-	  throw semantic_error ("invalid marker format use", e->tok);
+	  throw semantic_error ("invalid marker '" + sname + "' use", e->tok);
 	  break;
 	}
     }
 
-  string fname = string("_mark_format_get");
-
-  // Synthesize a function (if not already synthesized).
-  if (! function_synthesized)
-    {
-      function_synthesized = true;
-      functiondecl *fdecl = new functiondecl;
-      fdecl->tok = e->tok;
-      embeddedcode *ec = new embeddedcode;
-      ec->tok = e->tok;
-
-      ec->code = string("strlcpy (THIS->__retvalue, CONTEXT->data, MAXSTRINGLEN); /* pure */");
-      fdecl->name = fname;
-      fdecl->body = ec;
-      fdecl->type = pe_string;
-      sess.functions.push_back(fdecl);
-    }
+  string fname;
+  if (e->base_name == "$format") {
+    fname = string("_mark_format_get");
+  } else {
+    fname = string("_mark_name_get");
+  }
 
   // Synthesize a functioncall.
   functioncall* n = new functioncall;
@@ -7923,10 +7914,10 @@ mark_var_expanding_copy_visitor::visit_target_symbol (target_symbol* e)
 
   if (e->base_name.substr(0,4) == "$arg")
     visit_target_symbol_arg (e);
-  else if (e->base_name == "$format")
-    visit_target_symbol_format (e);
+  else if (e->base_name == "$format" || e->base_name == "$name")
+    visit_target_symbol_context (e);
   else
-    throw semantic_error ("invalid target symbol for marker, $argN or $format expected",
+    throw semantic_error ("invalid target symbol for marker, $argN, $name or $format expected",
 			  e->tok);
 }
 
@@ -8225,8 +8216,8 @@ mark_derived_probe_group::emit_module_decls (systemtap_session& s)
   s.op->newline(1) << "struct stap_marker_probe *smp = (struct stap_marker_probe *)probe_data;";
   common_probe_entryfn_prologue (s.op, "STAP_SESSION_RUNNING");
   s.op->newline() << "c->probe_point = smp->pp;";
-  s.op->newline() << "c->data = (char *)smp->format;";
-
+  s.op->newline() << "c->marker_name = smp->name;";
+  s.op->newline() << "c->marker_format = smp->format;";
   s.op->newline() << "c->mark_va_list = args;";
   s.op->newline() << "(*smp->ph) (c);";
   s.op->newline() << "c->mark_va_list = NULL;";
diff --git a/testsuite/ChangeLog b/testsuite/ChangeLog
index 045772a3..52892e8d 100644
--- a/testsuite/ChangeLog
+++ b/testsuite/ChangeLog
@@ -1,3 +1,7 @@
+2008-09-09  Masami Hiramatsu  <mhiramat@redhat.com>
+
+	* systemtap.base/marker.exp : Added testcases of $name.
+
 2008-09-06  Frank Ch. Eigler  <fche@elastic.org>
 
 	* systemtap.base/cmd_parse.exp: Adapt to sh-c-less "stap -c"
diff --git a/testsuite/systemtap.base/marker.exp b/testsuite/systemtap.base/marker.exp
index 89c0b8c3..0cacf60d 100644
--- a/testsuite/systemtap.base/marker.exp
+++ b/testsuite/systemtap.base/marker.exp
@@ -230,3 +230,48 @@ if {$kernel_markers_found == 0} {
 		    [lindex $kernel_marker_names 0] "foo"]
     stap_compile $TEST_NAME 0 $script
 }
+
+set TEST_NAME "K_MARKER18"
+if {$kernel_markers_found == 0} {
+    untested "$TEST_NAME : no kernel markers present"
+} else {
+    # Try compiling a script that prints the name string of a
+    # marker.
+    set script [format $kernel_script_arg \
+		    [lindex $kernel_marker_names 0] {\$name}]
+    stap_compile $TEST_NAME 1 $script
+}
+
+set TEST_NAME "K_MARKER19"
+if {$kernel_markers_found == 0} {
+    untested "$TEST_NAME : no kernel markers present"
+} else {
+    # Try compiling a script that writes to a marker name string
+    # (which isn't allowed).
+    set script [format $kernel_script_arg2 \
+		    [lindex $kernel_marker_names 0] {\$name}]
+    stap_compile $TEST_NAME 0 $script
+}
+
+set TEST_NAME "K_MARKER20"
+if {$kernel_markers_found == 0} {
+    untested "$TEST_NAME : no kernel markers present"
+} else {
+    # Try compiling a script that treats the marker name string as a
+    # structure (which isn't allowed).
+    set script [format $kernel_script_arg \
+		    [lindex $kernel_marker_names 0] {\$name->foo}]
+    stap_compile $TEST_NAME 0 $script
+}
+
+set TEST_NAME "K_MARKER21"
+if {$kernel_markers_found == 0} {
+    untested "$TEST_NAME : no kernel markers present"
+} else {
+    # Try compiling a script that treats the marker name string like
+    # an array (which isn't allowed).
+    set script [format $kernel_script_arg \
+		    [lindex $kernel_marker_names 0] {\$name\[0\]}]
+    stap_compile $TEST_NAME 0 $script
+}
+
diff --git a/translate.cxx b/translate.cxx
index 2fe33314..e5435fac 100644
--- a/translate.cxx
+++ b/translate.cxx
@@ -881,6 +881,8 @@ c_unparser::emit_common_header ()
   o->newline() << "struct kretprobe_instance *pi;";
   o->newline() << "int regparm;";
   o->newline() << "va_list *mark_va_list;";
+  o->newline() << "const char * marker_name;";
+  o->newline() << "const char * marker_format;";
   o->newline() << "void *data;";
   o->newline() << "#ifdef STP_TIMING";
   o->newline() << "Stat *statp;";