diff options
| -rw-r--r-- | tapsets.cxx | 16 |
1 files changed, 13 insertions, 3 deletions
diff --git a/tapsets.cxx b/tapsets.cxx index 103c39fa..a8653d8a 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -9242,7 +9242,7 @@ mark_builder::build(systemtap_session & sess, struct tracepoint_arg { - string name, c_type; + string name, c_type, typecast; bool usable, used, isptr; Dwarf_Die type_die; tracepoint_arg(): usable(false), used(false), isptr(false) {} @@ -9345,6 +9345,9 @@ tracepoint_var_expanding_visitor::visit_target_symbol_arg (target_symbol* e) if (lvalue && (!dw.sess.guru_mode || e->components.empty())) throw semantic_error("write to tracepoint variable '" + e->base_name + "' not permitted", e->tok); + // XXX: if a struct/union arg is passed by value, then writing to its fields + // is also meaningless until you dereference past a pointer member. It's + // harder to detect and prevent that though... if (e->components.empty()) { @@ -9685,6 +9688,14 @@ resolve_tracepoint_arg_type(tracepoint_arg& arg) if (dwarf_attr_integrate(&arg.type_die, DW_AT_type, &type_attr) && dwarf_formref_die(&type_attr, &arg.type_die)) arg.isptr = true; + arg.typecast = "(intptr_t)"; + return true; + case DW_TAG_structure_type: + case DW_TAG_union_type: + // for structs/unions which are passed by value, we turn it into + // a pointer that can be dereferenced. + arg.isptr = true; + arg.typecast = "(intptr_t)&"; return true; default: // should we consider other types too? @@ -9787,8 +9798,7 @@ tracepoint_derived_probe_group::emit_module_decls (systemtap_session& s) { s.op->newline() << "c->locals[0]." << p->name << ".__tracepoint_arg_" << p->args[j].name << " = (int64_t)"; - if (p->args[j].isptr) - s.op->line() << "(intptr_t)"; + s.op->line() << p->args[j].typecast; s.op->line() << "__tracepoint_arg_" << p->args[j].name << ";"; } s.op->newline() << p->name << " (c);"; |