elaborate.h

   1 // -*- C++ -*-
   2 // Copyright (C) 2005-2010 Red Hat Inc.
   3 //
   4 // This file is part of systemtap, and is free software.  You can
   5 // redistribute it and/or modify it under the terms of the GNU General
   6 // Public License (GPL); either version 2, or (at your option) any
   7 // later version.
   8
   9 #ifndef ELABORATE_H
  10 #define ELABORATE_H
  11
  12 #include "staptree.h"
  13 #include "parse.h"
  14 #include <string>
  15 #include <vector>
  16 //#include <iostream>
  17 #include <iosfwd>
  18 #include <sstream>
  19 #include <map>
  20 #include <list>
  21
  22 extern "C" {
  23 #include <elfutils/libdw.h>
  24 }
  25
  26 // ------------------------------------------------------------------------
  27
  28 struct derived_probe;
  29 struct match_node;
  30
  31 struct symresolution_info: public traversing_visitor
  32 {
  33 protected:
  34   systemtap_session& session;
  35
  36 public:
  37   functiondecl* current_function;
  38   derived_probe* current_probe;
  39   symresolution_info (systemtap_session& s);
  40
  41   vardecl* find_var (const std::string& name, int arity, const token *tok);
  42   functiondecl* find_function (const std::string& name, unsigned arity);
  43
  44   void visit_block (block *s);
  45   void visit_symbol (symbol* e);
  46   void visit_foreach_loop (foreach_loop* e);
  47   void visit_arrayindex (arrayindex* e);
  48   void visit_functioncall (functioncall* e);
  49   void visit_delete_statement (delete_statement* s);
  50 };
  51
  52
  53 struct typeresolution_info: public visitor
  54 {
  55   typeresolution_info (systemtap_session& s);
  56   systemtap_session& session;
  57   unsigned num_newly_resolved;
  58   unsigned num_still_unresolved;
  59   bool assert_resolvability;
  60   functiondecl* current_function;
  61   derived_probe* current_probe;
  62   std::vector <const token*> resolved_toks; // account for type mis-
  63   std::vector <const token*> printed_toks;  // matches (BZ 9719)
  64
  65   void check_arg_type (exp_type wanted, expression* arg);
  66   void check_local (vardecl* v);
  67   void mismatch (const token* tok, exp_type t1, exp_type t2);
  68   void unresolved (const token* tok);
  69   void resolved (const token* tok, exp_type t);
  70   void invalid (const token* tok, exp_type t);
  71
  72   exp_type t; // implicit parameter for nested visit call; may clobber
  73
  74   void visit_block (block* s);
  75   void visit_try_block (try_block* s);
  76   void visit_embeddedcode (embeddedcode* s);
  77   void visit_null_statement (null_statement* s);
  78   void visit_expr_statement (expr_statement* s);
  79   void visit_if_statement (if_statement* s);
  80   void visit_for_loop (for_loop* s);
  81   void visit_foreach_loop (foreach_loop* s);
  82   void visit_return_statement (return_statement* s);
  83   void visit_delete_statement (delete_statement* s);
  84   void visit_next_statement (next_statement* s);
  85   void visit_break_statement (break_statement* s);
  86   void visit_continue_statement (continue_statement* s);
  87   void visit_literal_string (literal_string* e);
  88   void visit_literal_number (literal_number* e);
  89   void visit_embedded_expr (embedded_expr* e);
  90   void visit_binary_expression (binary_expression* e);
  91   void visit_unary_expression (unary_expression* e);
  92   void visit_pre_crement (pre_crement* e);
  93   void visit_post_crement (post_crement* e);
  94   void visit_logical_or_expr (logical_or_expr* e);
  95   void visit_logical_and_expr (logical_and_expr* e);
  96   void visit_array_in (array_in* e);
  97   void visit_comparison (comparison* e);
  98   void visit_concatenation (concatenation* e);
  99   void visit_ternary_expression (ternary_expression* e);
 100   void visit_assignment (assignment* e);
 101   void visit_symbol (symbol* e);
 102   void visit_target_symbol (target_symbol* e);
 103   void visit_arrayindex (arrayindex* e);
 104   void visit_functioncall (functioncall* e);
 105   void visit_print_format (print_format* e);
 106   void visit_stat_op (stat_op* e);
 107   void visit_hist_op (hist_op* e);
 108   void visit_cast_op (cast_op* e);
 109   void visit_defined_op (defined_op* e);
 110 };
 111
 112
 113 // ------------------------------------------------------------------------
 114
 115
 116 // A derived_probe is a probe that has been elaborated by
 117 // binding to a matching provider.  The locations std::vector
 118 // may be smaller or larger than the base probe, since a
 119 // provider may transform it.
 120
 121 class translator_output;
 122 class derived_probe_group;
 123
 124 struct derived_probe: public probe
 125 {
 126   derived_probe (probe* b);
 127   derived_probe (probe* b, probe_point* l);
 128   probe* base; // the original parsed probe
 129   virtual const probe* basest () const { return base->basest(); }
 130   virtual const probe* almost_basest () const { return base->almost_basest() ?: this; }
 131   virtual ~derived_probe () {}
 132   virtual void join_group (systemtap_session& s) = 0;
 133   virtual probe_point* sole_location () const;
 134   virtual probe_point* script_location () const;
 135   virtual void printsig (std::ostream &o) const;
 136   // return arguments of probe if there
 137   virtual void getargs (std::list<std::string> &arg_set) const {}
 138   void printsig_nested (std::ostream &o) const;
 139   virtual void collect_derivation_chain (std::vector<probe*> &probes_list);
 140
 141   virtual void print_dupe_stamp(std::ostream&) {}
 142   // To aid duplication elimination, print a stamp which uniquely identifies
 143   // the code that will be added to the probe body.  (Doesn't need to be the
 144   // actual code...)
 145
 146   virtual void initialize_probe_context_vars (translator_output*) {}
 147   // From within unparser::emit_probe, initialized any extra variables
 148   // in this probe's context locals.
 149
 150   virtual void emit_probe_local_init (translator_output*) {}
 151   // From within unparser::emit_probe, emit any extra processing block
 152   // for this probe.
 153
 154   virtual void emit_unprivileged_assertion (translator_output*);
 155   // From within unparser::emit_probe, emit any unprivileged mode
 156   // checking for this probe.
 157
 158 public:
 159   static void emit_common_header (translator_output* o);
 160   // from c_unparser::emit_common_header
 161   // XXX: probably can move this stuff to a probe_group::emit_module_decls
 162
 163   static void emit_process_owner_assertion (translator_output*);
 164   // From within unparser::emit_probe, emit a check that the current
 165   // process belongs to the user.
 166
 167   static void print_dupe_stamp_unprivileged(std::ostream& o);
 168   static void print_dupe_stamp_unprivileged_process_owner(std::ostream& o);
 169
 170   virtual bool needs_global_locks () { return true; }
 171   // by default, probes need locks around global variables
 172
 173   // Location of semaphores to activate sdt probes
 174   Dwarf_Addr sdt_semaphore_addr;
 175 };
 176
 177 // ------------------------------------------------------------------------
 178
 179 struct unparser;
 180
 181 // Various derived classes derived_probe_group manage the
 182 // registration/invocation/unregistration of sibling probes.
 183 struct derived_probe_group
 184 {
 185   virtual ~derived_probe_group () {}
 186
 187   virtual void emit_module_decls (systemtap_session& s) = 0;
 188   // The _decls-generated code may assume that declarations such as
 189   // the context, embedded-C code, function and probe handler bodies
 190   // are all already generated.  That is, _decls is called near the
 191   // end of the code generation process.  It should minimize the
 192   // number of separate variables (and to a lesser extent, their
 193   // size).
 194
 195   virtual void emit_module_init (systemtap_session& s) = 0;
 196   // The _init-generated code may assume that it is called only once.
 197   // If that code fails at run time, it must set rc=1 and roll back
 198   // any partial initializations, for its _exit friend will NOT be
 199   // invoked.  The generated code may use pre-declared "int i, j;".
 200
 201   virtual void emit_module_exit (systemtap_session& s) = 0;
 202   // The _exit-generated code may assume that it is executed exactly
 203   // zero times (if the _init-generated code failed) or once.  (_exit
 204   // itself may be called a few times, to generate the code in a few
 205   // different places in the probe module.)
 206   // The generated code may use pre-declared "int i, j;".
 207 };
 208
 209
 210 // ------------------------------------------------------------------------
 211
 212 typedef std::map<std::string, literal*> literal_map_t;
 213
 214 struct derived_probe_builder
 215 {
 216   virtual void build(systemtap_session & sess,
 217                      probe* base,
 218                      probe_point* location,
 219                      literal_map_t const & parameters,
 220                      std::vector<derived_probe*> & finished_results) = 0;
 221   virtual ~derived_probe_builder() {}
 222   virtual void build_no_more (systemtap_session &) {}
 223
 224   static bool has_null_param (literal_map_t const & parameters,
 225                               const std::string& key);
 226   static bool get_param (literal_map_t const & parameters,
 227                          const std::string& key, std::string& value);
 228   static bool get_param (literal_map_t const & parameters,
 229                          const std::string& key, int64_t& value);
 230 };
 231
 232
 233 struct
 234 match_key
 235 {
 236   std::string name;
 237   bool have_parameter;
 238   exp_type parameter_type;
 239
 240   match_key(std::string const & n);
 241   match_key(probe_point::component const & c);
 242
 243   match_key & with_number();
 244   match_key & with_string();
 245   std::string str() const;
 246   bool operator<(match_key const & other) const;
 247   bool globmatch(match_key const & other) const;
 248 };
 249
 250
 251 class
 252 match_node
 253 {
 254   typedef std::map<match_key, match_node*> sub_map_t;
 255   typedef std::map<match_key, match_node*>::iterator sub_map_iterator_t;
 256   sub_map_t sub;
 257   std::vector<derived_probe_builder*> ends;
 258
 259  public:
 260   match_node();
 261
 262   void find_and_build (systemtap_session& s,
 263                        probe* p, probe_point *loc, unsigned pos,
 264                        std::vector<derived_probe *>& results);
 265   void build_no_more (systemtap_session &s);
 266
 267   match_node* bind(match_key const & k);
 268   match_node* bind(std::string const & k);
 269   match_node* bind_str(std::string const & k);
 270   match_node* bind_num(std::string const & k);
 271   match_node* bind_unprivileged(bool b = true);
 272   void bind(derived_probe_builder* e);
 273
 274 private:
 275   bool unprivileged_ok;
 276 };
 277
 278 // ------------------------------------------------------------------------
 279
 280 struct
 281 alias_expansion_builder
 282   : public derived_probe_builder
 283 {
 284   probe_alias * alias;
 285
 286   alias_expansion_builder(probe_alias * a)
 287     : alias(a)
 288   {}
 289
 290   virtual void build(systemtap_session & sess,
 291                      probe * use,
 292                      probe_point * location,
 293                      std::map<std::string, literal *> const &,
 294                      std::vector<derived_probe *> & finished_results);
 295
 296   bool checkForRecursiveExpansion (probe *use);
 297 };
 298
 299 // ------------------------------------------------------------------------
 300
 301 /* struct systemtap_session moved to session.h */
 302
 303 int semantic_pass (systemtap_session& s);
 304 void derive_probes (systemtap_session& s,
 305                     probe *p, std::vector<derived_probe*>& dps,
 306                     bool optional = false);
 307
 308 // A helper we use here and in translate, for pulling symbols out of lvalue
 309 // expressions.
 310 symbol * get_symbol_within_expression (expression *e);
 311
 312
 313 struct unparser;
 314
 315
 316 #endif // ELABORATE_H
 317
 318 /* vim: set sw=2 ts=8 cino=>4,n-2,{2,^-2,t0,(0,u0,w1,M1 : */