gold/attributes.h

   1 // attributes.h -- object attributes for gold   -*- C++ -*-
   2
   3 // Copyright (C) 2009-2019 Free Software Foundation, Inc.
   4 // Written by Doug Kwan <dougkwan@google.com>.
   5 // This file contains code adapted from BFD.
   6
   7 // This file is part of gold.
   8
   9 // This program is free software; you can redistribute it and/or modify
  10 // it under the terms of the GNU General Public License as published by
  11 // the Free Software Foundation; either version 3 of the License, or
  12 // (at your option) any later version.
  13
  14 // This program is distributed in the hope that it will be useful,
  15 // but WITHOUT ANY WARRANTY; without even the implied warranty of
  16 // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17 // GNU General Public License for more details.
  18
  19 // You should have received a copy of the GNU General Public License
  20 // along with this program; if not, write to the Free Software
  21 // Foundation, Inc., 51 Franklin Street - Fifth Floor, Boston,
  22 // MA 02110-1301, USA.
  23
  24 // Handle object attributes.
  25
  26 #ifndef GOLD_ATTRIBUTES_H
  27 #define GOLD_ATTRIBUTES_H
  28
  29 #include <map>
  30
  31 #include "parameters.h"
  32 #include "target.h"
  33 #include "output.h"
  34 #include "reduced_debug_output.h"
  35
  36 namespace gold
  37 {
  38
  39 // Object attribute values.  The attribute tag is not stored in this object.
  40
  41 class Object_attribute
  42 {
  43  public:
  44   // The value of an object attribute.  The type indicates whether the
  45   // attribute holds and integer, a string, or both.  It can also indicate that
  46   // there can be no default (i.e. all values must be written to file, even
  47   // zero).
  48   enum
  49   {
  50     ATTR_TYPE_FLAG_INT_VAL = (1 << 0),
  51     ATTR_TYPE_FLAG_STR_VAL = (1 << 1),
  52     ATTR_TYPE_FLAG_NO_DEFAULT = (1 << 2)
  53   };
  54
  55   // Object attributes may either be defined by the processor ABI, index
  56   // OBJ_ATTR_PROC in the *_obj_attributes arrays, or be GNU-specific
  57   // (and possibly also processor-specific), index OBJ_ATTR_GNU.
  58   enum
  59   {
  60     OBJ_ATTR_PROC,
  61     OBJ_ATTR_GNU,
  62     OBJ_ATTR_FIRST = OBJ_ATTR_PROC,
  63     OBJ_ATTR_LAST = OBJ_ATTR_GNU
  64   };
  65
  66   // The following object attribute tags are taken as generic, for all
  67   // targets and for "gnu" where there is no target standard.
  68   enum
  69   {
  70     Tag_NULL = 0,
  71     Tag_File = 1,
  72     Tag_Section = 2,
  73     Tag_Symbol = 3,
  74     Tag_compatibility = 32
  75   };
  76
  77   Object_attribute()
  78    : type_(0), int_value_(0), string_value_()
  79   { }
  80
  81   // Copying constructor.  We need to implement this to copy the string value.
  82   Object_attribute(const Object_attribute& oa)
  83    : type_(oa.type_), int_value_(oa.int_value_), string_value_(oa.string_value_)
  84   { }
  85
  86   ~Object_attribute()
  87   { }
  88
  89   // Assignment operator.  We need to implement this to copy the string value.
  90   Object_attribute&
  91   operator=(const Object_attribute& source)
  92   {
  93     this->type_ = source.type_;
  94     this->int_value_ = source.int_value_;
  95     this->string_value_ = source.string_value_;
  96     return *this;
  97   }
  98
  99   // Return attribute type.
 100   int
 101   type() const
 102   { return this->type_; }
 103
 104   // Set attribute type.
 105   void
 106   set_type(int type)
 107   { this->type_ = type; }
 108
 109   // Return integer value.
 110   unsigned int
 111   int_value() const
 112   { return this->int_value_; }
 113
 114   // Set integer value.
 115   void
 116   set_int_value(unsigned int i)
 117   { this->int_value_ = i; }
 118
 119   // Return string value.
 120   const std::string&
 121   string_value() const
 122   { return this->string_value_; }
 123
 124   // Set string value.
 125   void
 126   set_string_value(const std::string& s)
 127   { this->string_value_ = s; }
 128
 129   void
 130   set_string_value(const char* s)
 131   { this->string_value_ = s; }
 132
 133   // Whether attribute type has integer value.
 134   static bool
 135   attribute_type_has_int_value(int type)
 136   { return (type & ATTR_TYPE_FLAG_INT_VAL) != 0; }
 137
 138   // Whether attribute type has string value.
 139   static bool
 140   attribute_type_has_string_value(int type)
 141   { return (type & ATTR_TYPE_FLAG_STR_VAL) != 0; }
 142
 143   // Whether attribute type has no default value.
 144   static bool
 145   attribute_type_has_no_default(int type)
 146   { return (type & ATTR_TYPE_FLAG_NO_DEFAULT) != 0; }
 147
 148   // Whether this has default value (0/"").
 149   bool
 150   is_default_attribute() const;
 151
 152   // Return ULEB128 encoded size of tag and attribute.
 153   size_t
 154   size(int tag) const;
 155
 156   // Whether this matches another object attribute in merging.
 157   bool
 158   matches(const Object_attribute& oa) const;
 159
 160   // Write to attribute with tag to BUFFER.
 161   void
 162   write(int tag, std::vector<unsigned char>* buffer) const;
 163
 164   // Determine what arguments an attribute tag takes.
 165   static int
 166   arg_type(int vendor, int tag)
 167   {
 168     switch (vendor)
 169       {
 170       case OBJ_ATTR_PROC:
 171         return parameters->target().attribute_arg_type(tag);
 172       case OBJ_ATTR_GNU:
 173         return Object_attribute::gnu_arg_type(tag);
 174       default:
 175         gold_unreachable();
 176      }
 177   }
 178
 179  private:
 180   // Determine whether a GNU object attribute tag takes an integer, a
 181   // string or both.  */
 182   static int
 183   gnu_arg_type(int tag)
 184   {
 185     // Except for Tag_compatibility, for GNU attributes we follow the
 186     // same rule ARM ones > 32 follow: odd-numbered tags take strings
 187     // and even-numbered tags take integers.  In addition, tag & 2 is
 188     // nonzero for architecture-independent tags and zero for
 189     // architecture-dependent ones.
 190     if (tag == Object_attribute::Tag_compatibility)
 191       return ATTR_TYPE_FLAG_INT_VAL | ATTR_TYPE_FLAG_STR_VAL;
 192     else
 193       return (tag & 1) != 0 ? ATTR_TYPE_FLAG_STR_VAL : ATTR_TYPE_FLAG_INT_VAL;
 194   }
 195
 196   // Attribute type.
 197   int type_;
 198   // Integer value.
 199   int int_value_;
 200   // String value.
 201   std::string string_value_;
 202 };
 203
 204 // This class contains attributes of a particular vendor.
 205
 206 class Vendor_object_attributes
 207 {
 208  public:
 209   // The maximum number of known object attributes for any target.
 210   static const int NUM_KNOWN_ATTRIBUTES = 71;
 211
 212   Vendor_object_attributes(int vendor)
 213     : vendor_(vendor), other_attributes_()
 214   { }
 215
 216   // Copying constructor.
 217   Vendor_object_attributes(const Vendor_object_attributes&);
 218
 219   ~Vendor_object_attributes()
 220   {
 221     for (Other_attributes::iterator p = this->other_attributes_.begin();
 222          p != this->other_attributes_.end();
 223          ++p)
 224       delete p->second;
 225   }
 226
 227   // Size of this in number of bytes.
 228   size_t
 229   size() const;
 230
 231   // Name of this written vendor subsection.
 232   const char*
 233   name() const
 234   {
 235     return (this->vendor_ == Object_attribute::OBJ_ATTR_PROC
 236             ? parameters->target().attributes_vendor()
 237             : "gnu");
 238   }
 239
 240   // Return an array of known attributes.
 241   Object_attribute*
 242   known_attributes()
 243   { return &this->known_attributes_[0]; }
 244
 245   const Object_attribute*
 246   known_attributes() const
 247   { return &this->known_attributes_[0]; }
 248
 249   typedef std::map<int, Object_attribute*> Other_attributes;
 250
 251   // Return attributes other than the known ones.
 252   Other_attributes*
 253   other_attributes()
 254   { return &this->other_attributes_; }
 255
 256   const Other_attributes*
 257   other_attributes() const
 258   { return &this->other_attributes_; }
 259
 260   // Return a new attribute associated with TAG.
 261   Object_attribute*
 262   new_attribute(int tag);
 263
 264   // Get an attribute
 265   Object_attribute*
 266   get_attribute(int tag);
 267
 268   const Object_attribute*
 269   get_attribute(int tag) const;
 270
 271   // Write to BUFFER.
 272   void
 273   write(std::vector<unsigned char>* buffer) const;
 274
 275  private:
 276   // Vendor of the object attributes.
 277   int vendor_;
 278   // Attributes with known tags.  There are store in an array for fast
 279   // access.
 280   Object_attribute known_attributes_[NUM_KNOWN_ATTRIBUTES];
 281   // Attributes with known tags.  There are stored in a sorted container.
 282   Other_attributes other_attributes_;
 283 };
 284
 285 // This class contains contents of an attributes section.
 286
 287 class Attributes_section_data
 288 {
 289  public:
 290   // Construct an Attributes_section_data object by parsing section contents
 291   // in VIEW of SIZE.
 292   Attributes_section_data(const unsigned char* view, section_size_type size);
 293
 294   // Copying constructor.
 295   Attributes_section_data(const Attributes_section_data& asd)
 296   {
 297     for (int vendor = Object_attribute::OBJ_ATTR_FIRST;
 298          vendor <= Object_attribute::OBJ_ATTR_LAST;
 299          ++vendor)
 300       this->vendor_object_attributes_[vendor] =
 301         new Vendor_object_attributes(*asd.vendor_object_attributes_[vendor]);
 302   }
 303
 304   ~Attributes_section_data()
 305   {
 306     for (int vendor = Object_attribute::OBJ_ATTR_FIRST;
 307          vendor <= Object_attribute::OBJ_ATTR_LAST;
 308          ++vendor)
 309       delete this->vendor_object_attributes_[vendor];
 310   }
 311
 312   // Return the size of this as number of bytes.
 313   size_t
 314   size() const;
 315
 316   // Return an array of known attributes.
 317   Object_attribute*
 318   known_attributes(int vendor)
 319   {
 320     gold_assert(vendor >= OBJ_ATTR_FIRST && vendor <= OBJ_ATTR_LAST);
 321     return this->vendor_object_attributes_[vendor]->known_attributes();
 322   }
 323
 324   const Object_attribute*
 325   known_attributes(int vendor) const
 326   {
 327     gold_assert(vendor >= OBJ_ATTR_FIRST && vendor <= OBJ_ATTR_LAST);
 328     return this->vendor_object_attributes_[vendor]->known_attributes();
 329   }
 330
 331   // Return the other attributes.
 332   Vendor_object_attributes::Other_attributes*
 333   other_attributes(int vendor)
 334   {
 335     gold_assert(vendor >= OBJ_ATTR_FIRST && vendor <= OBJ_ATTR_LAST);
 336     return this->vendor_object_attributes_[vendor]->other_attributes();
 337   }
 338
 339   // Return the other attributes.
 340   const Vendor_object_attributes::Other_attributes*
 341   other_attributes(int vendor) const
 342   {
 343     gold_assert(vendor >= OBJ_ATTR_FIRST && vendor <= OBJ_ATTR_LAST);
 344     return this->vendor_object_attributes_[vendor]->other_attributes();
 345   }
 346
 347   // Return an attribute.
 348   Object_attribute*
 349   get_attribute(int vendor, int tag)
 350   {
 351     gold_assert(vendor >= OBJ_ATTR_FIRST && vendor <= OBJ_ATTR_LAST);
 352     return this->vendor_object_attributes_[vendor]->get_attribute(tag);
 353   }
 354
 355   const Object_attribute*
 356   get_attribute(int vendor, int tag) const
 357   {
 358     gold_assert(vendor >= OBJ_ATTR_FIRST && vendor <= OBJ_ATTR_LAST);
 359     return this->vendor_object_attributes_[vendor]->get_attribute(tag);
 360   }
 361
 362   // Merge target-independent attributes from another Attributes_section_data
 363   // of an object called NAME.
 364   void
 365   merge(const char* name, const Attributes_section_data* pasd);
 366
 367   // Write to byte stream in an unsigned char vector.
 368   void
 369   write(std::vector<unsigned char>*) const;
 370
 371  private:
 372   // For convenience.
 373   static const int OBJ_ATTR_FIRST = Object_attribute::OBJ_ATTR_FIRST;
 374   static const int OBJ_ATTR_LAST = Object_attribute::OBJ_ATTR_LAST;
 375
 376   // Vendor object attributes.
 377   Vendor_object_attributes* vendor_object_attributes_[OBJ_ATTR_LAST+1];
 378 };
 379
 380 // This class is used for writing out an Attribute_section_data.
 381
 382 class Output_attributes_section_data : public Output_section_data
 383 {
 384  public:
 385   Output_attributes_section_data(const Attributes_section_data& asd)
 386     : Output_section_data(1), attributes_section_data_(asd)
 387   { }
 388
 389  protected:
 390   // Write to a map file.
 391   void
 392   do_print_to_mapfile(Mapfile* mapfile) const
 393   { mapfile->print_output_data(this, _("** attributes")); }
 394
 395   // Write the data to the output file.
 396   void
 397   do_write(Output_file*);
 398
 399   // Set final data size.
 400   void
 401   set_final_data_size()
 402   { this->set_data_size(attributes_section_data_.size()); }
 403
 404  private:
 405   // Attributes_section_data corresponding to this.
 406   const Attributes_section_data& attributes_section_data_;
 407 };
 408
 409 } // End namespace gold.
 410
 411 #endif  // !defined(GOLD_ATTRIBUTES_H)