diff options
Diffstat (limited to 'tapsets.cxx')
| -rw-r--r-- | tapsets.cxx | 69 |
1 files changed, 43 insertions, 26 deletions
diff --git a/tapsets.cxx b/tapsets.cxx index 46cc3a65..ca439ede 100644 --- a/tapsets.cxx +++ b/tapsets.cxx @@ -1846,8 +1846,8 @@ struct dwarf_var_expanding_visitor: public var_expanding_visitor dwarf_var_expanding_visitor(dwarf_query & q, Dwarf_Die *sd, Dwarf_Addr a): q(q), scope_die(sd), addr(a), add_block(NULL), add_call_probe(NULL), saved_longs(0), saved_strings(0), visited(false) {} - expression* gen_mapped_saved_return(target_symbol* e); - expression* gen_kretprobe_saved_return(target_symbol* e); + expression* gen_mapped_saved_return(expression* e, const string& base_name); + expression* gen_kretprobe_saved_return(expression* e, const string& base_name); void visit_target_symbol_saved_return (target_symbol* e); void visit_target_symbol_context (target_symbol* e); void visit_target_symbol (target_symbol* e); @@ -2014,12 +2014,27 @@ dwarf_var_expanding_visitor::visit_target_symbol_saved_return (target_symbol* e) return; } + // Attempt the expansion directly first, so if there's a problem with the + // variable we won't have a bogus entry probe lying around. Like in + // saveargs(), we pretend for a moment that we're not in a .return. + bool saved_has_return = q.has_return; + q.has_return = false; + expression *repl = e; + replace (repl); + q.has_return = saved_has_return; + target_symbol* n = dynamic_cast<target_symbol*>(repl); + if (n && n->saved_conversion_error) + { + provide (repl); + return; + } + expression *exp; if (!q.has_process && strverscmp(q.sess.kernel_base_release.c_str(), "2.6.25") >= 0) - exp = gen_kretprobe_saved_return(e); + exp = gen_kretprobe_saved_return(repl, e->base_name); else - exp = gen_mapped_saved_return(e); + exp = gen_mapped_saved_return(repl, e->base_name); // Provide the variable to our parent so it can be used as a // substitute for the target symbol. @@ -2032,7 +2047,8 @@ dwarf_var_expanding_visitor::visit_target_symbol_saved_return (target_symbol* e) } expression* -dwarf_var_expanding_visitor::gen_mapped_saved_return(target_symbol* e) +dwarf_var_expanding_visitor::gen_mapped_saved_return(expression* e, + const string& base_name) { // We've got to do several things here to handle target // variables in return probes. @@ -2046,7 +2062,7 @@ dwarf_var_expanding_visitor::gen_mapped_saved_return(target_symbol* e) // _dwarf_tvar_{name}_{num}_ctr string aname = (string("_dwarf_tvar_") - + e->base_name.substr(1) + + base_name.substr(1) + "_" + lex_cast(tick++)); vardecl* vd = new vardecl; vd->name = aname; @@ -2267,7 +2283,8 @@ dwarf_var_expanding_visitor::gen_mapped_saved_return(target_symbol* e) expression* -dwarf_var_expanding_visitor::gen_kretprobe_saved_return(target_symbol* e) +dwarf_var_expanding_visitor::gen_kretprobe_saved_return(expression* e, + const string& base_name) { // The code for this is simple. // @@ -2286,7 +2303,7 @@ dwarf_var_expanding_visitor::gen_kretprobe_saved_return(target_symbol* e) // character is a '$', then we're looking at a $$vars, $$parms, or $$locals. // XXX We need real type resolution here, especially if we are ever to // support an @entry construct. - if (e->base_name[1] == '$') + if (base_name[1] == '$') { index = saved_strings++; setfn = "_set_kretprobe_string"; @@ -2450,14 +2467,14 @@ dwarf_var_expanding_visitor::visit_target_symbol (target_symbol *e) bool defined_being_checked = (defined_ops.size() > 0 && (defined_ops.top()->operand == e)); // In this mode, we avoid hiding errors or generating extra code such as for .return saved $vars - try + try { bool lvalue = is_active_lvalue(e); if (lvalue && !q.sess.guru_mode) throw semantic_error("write to target variable not permitted", e->tok); // XXX: process $context vars should be writeable - + // See if we need to generate a new probe to save/access function // parameters from a return probe. PR 1382. if (q.has_return @@ -2478,28 +2495,28 @@ dwarf_var_expanding_visitor::visit_target_symbol (target_symbol *e) { if (lvalue) throw semantic_error("cannot write to context variable", e->tok); - + if (e->addressof) throw semantic_error("cannot take address of context variable", e->tok); - + visit_target_symbol_context(e); return; } - + // Synthesize a function. functiondecl *fdecl = new functiondecl; fdecl->tok = e->tok; embeddedcode *ec = new embeddedcode; ec->tok = e->tok; - + string fname = (string(lvalue ? "_dwarf_tvar_set" : "_dwarf_tvar_get") + "_" + e->base_name.substr(1) + "_" + lex_cast(tick++)); - + // PR10601: adapt to kernel-vs-userspace loc2c-runtime ec->code += "\n#define fetch_register " + string(q.has_process?"u":"k") + "_fetch_register\n"; ec->code += "#define store_register " + string(q.has_process?"u":"k") + "_store_register\n"; - + if (q.has_return && (e->base_name == "$return")) { ec->code += q.dw.literal_stmt_for_return (scope_die, @@ -2529,7 +2546,7 @@ dwarf_var_expanding_visitor::visit_target_symbol (target_symbol *e) fdecl->name = fname; fdecl->body = ec; - + // Any non-literal indexes need to be passed in too. for (unsigned i = 0; i < e->components.size(); ++i) if (e->components[i].type == target_symbol::comp_expression_array_index) @@ -2540,17 +2557,17 @@ dwarf_var_expanding_visitor::visit_target_symbol (target_symbol *e) v->tok = e->tok; fdecl->formal_args.push_back(v); } - + if (lvalue) { // Modify the fdecl so it carries a single pe_long formal // argument called "value". - + // FIXME: For the time being we only support setting target // variables which have base types; these are 'pe_long' in // stap's type vocabulary. Strings and pointers might be // reasonable, some day, but not today. - + vardecl *v = new vardecl; v->type = pe_long; v->name = "value"; @@ -2558,18 +2575,18 @@ dwarf_var_expanding_visitor::visit_target_symbol (target_symbol *e) fdecl->formal_args.push_back(v); } q.sess.functions[fdecl->name]=fdecl; - + // Synthesize a functioncall. functioncall* n = new functioncall; n->tok = e->tok; n->function = fname; n->referent = 0; // NB: must not resolve yet, to ensure inclusion in session - + // Any non-literal indexes need to be passed in too. for (unsigned i = 0; i < e->components.size(); ++i) if (e->components[i].type == target_symbol::comp_expression_array_index) n->args.push_back(require(e->components[i].expr_index)); - + if (lvalue) { // Provide the functioncall to our parent, so that it can be @@ -2578,7 +2595,7 @@ dwarf_var_expanding_visitor::visit_target_symbol (target_symbol *e) assert(!target_symbol_setter_functioncalls.empty()); *(target_symbol_setter_functioncalls.top()) = n; } - + provide (n); } catch (const semantic_error& er) @@ -2599,9 +2616,9 @@ dwarf_var_expanding_visitor::visit_target_symbol (target_symbol *e) // function ("*") { $var } e->chain (saveme); } - else + else { - // Upon user request for ignoring context, the symbol is replaced + // Upon user request for ignoring context, the symbol is replaced // with a literal 0 and a warning message displayed literal_number* ln_zero = new literal_number (0); ln_zero->tok = e->tok; |