Changed method of getting the value of $syscall.

2008-07-14  David Smith  <dsmith@redhat.com>

	* tapsets.cxx
	(utrace_var_expanding_copy_visitor::visit_target_symbol):
	Synthesize a function to get the value of $syscall.

2008-07-14  David Smith  <dsmith@redhat.com>

	* i686/registers.stp: Removed syscall_nr function.
	* x86_64/registers.stp: Ditto.

1 files changed, 23 insertions, 3 deletions

diff --git a/tapsets.cxx b/tapsets.cxx
index 21c9fb54..2f9dd2d0 100644
--- a/tapsets.cxx
+++ b/tapsets.cxx
@@ -5355,11 +5355,15 @@ struct utrace_var_expanding_copy_visitor: public var_expanding_copy_visitor
   string probe_name;
   enum utrace_derived_probe_flags flags;
   bool target_symbol_seen;
+  static bool syscall_function_added;
 
   void visit_target_symbol (target_symbol* e);
 };
 
 
+bool utrace_var_expanding_copy_visitor::syscall_function_added = false;
+
+
 utrace_derived_probe::utrace_derived_probe (systemtap_session &s,
                                             probe* p, probe_point* l,
                                             bool hp, string &pn, int64_t pd,
@@ -5426,11 +5430,27 @@ utrace_var_expanding_copy_visitor::visit_target_symbol (target_symbol* e)
   // Remember that we've seen a target variable.
   target_symbol_seen = true;
 
-  // We're going to substitute a synthesized 'syscall_nr' function
-  // call for the '$syscall' reference.
+  // Synthesize a function to grab the syscall .
+  if (! syscall_function_added)
+    {
+      functiondecl *fdecl = new functiondecl;
+      fdecl->tok = e->tok;
+      embeddedcode *ec = new embeddedcode;
+      ec->tok = e->tok;
+      ec->code = string("THIS->__retvalue = __stp_user_syscall_nr(CONTEXT->regs); /* pure */");
+
+      fdecl->name = string("_syscall_nr_get");
+      fdecl->body = ec;
+      fdecl->type = pe_long;
+      sess.functions.push_back(fdecl);
+      syscall_function_added = true;
+    }
+
+  // We're going to substitute a synthesized '_syscall_nr_get'
+  // function call for the '$syscall' reference.
   functioncall* n = new functioncall;
   n->tok = e->tok;
-  n->function = "syscall_nr";
+  n->function = "_syscall_nr_get";
   n->referent = 0; // NB: must not resolve yet, to ensure inclusion in session
 
   provide <functioncall*> (this, n);