Merge memory checking from sandbox

Change-id: Ibce845d0

1 files changed, 202 insertions, 0 deletions

diff --git a/elff/dwarf_die.h b/elff/dwarf_die.h
new file mode 100644
index 0000000..21dea37
--- /dev/null
+++ b/elff/dwarf_die.h
@@ -0,0 +1,202 @@
+/* Copyright (C) 2007-2010 The Android Open Source Project

+**

+** This software is licensed under the terms of the GNU General Public

+** License version 2, as published by the Free Software Foundation, and

+** may be copied, distributed, and modified under those terms.

+**

+** This program is distributed in the hope that it will be useful,

+** but WITHOUT ANY WARRANTY; without even the implied warranty of

+** MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

+** GNU General Public License for more details.

+*/

+

+/*

+ * Contains declarations of classes defined for a variety of DWARF objects.

+ */

+

+#ifndef ELFF_DWARF_DIE_H_

+#define ELFF_DWARF_DIE_H_

+

+#include "dwarf_defs.h"

+#include "elf_alloc.h"

+

+class ElfFile;

+class DwarfCU;

+

+/* Encapsulates an object that wraps up a DIE, cached during

+ * ELF file parsing.

+ */

+class DIEObject : public DwarfAllocBase {

+ public:

+  /* Constructs DIEObject intance.

+   * Param:

+   *  die - DIE represented with this instance.

+   *  parent_cu - Compilation unit this DIE belongs to.

+   *  parent_die - Parent DIE object for this DIE. This parameter can be NULL

+   *    only for compilation unit DIEs.

+   */

+  DIEObject(const Dwarf_DIE* die, DwarfCU* parent_cu, DIEObject* parent_die)

+      : die_(die),

+        parent_cu_(parent_cu),

+        parent_die_(parent_die),

+        prev_sibling_(NULL),

+        last_child_(NULL) {

+  }

+

+  /* Destructs DIEObject intance. */

+  ~DIEObject();

+

+  /* Gets ELF file this DIE belongs to. */

+  ElfFile* elf_file() const;

+

+  /* Gets DWARF tag (DW_TAG_Xxx) for the DIE represented with this instance. */

+  Dwarf_Tag get_tag() const;

+

+  /* Gets the best name for this DIE.

+   * Some DIEs (such as inline routine DIEs) may have no DW_AT_name property,

+   * but may reference to another DIE that may contain DIE name. This method

+   * tries its best to get DIE name by iterating through different methods of

+   * naming the DIE.

+   * Return:

+   *  Name for this DIE, or NULL if it was not possible to find a relevant DIE

+   *  with DW_AT_name property.

+   */

+  const char* get_name() const;

+

+  /* Gets DIE's attribute by its ID.

+   * Param:

+   *  at_id - ID (DW_AT_Xxx) of the attribute to get.

+   *  attr - Upon successful return contains requested attribute information.

+   * Return:

+   *  true on success, or false if attribute for the given ID doesn't exist

+   *  in the DIE's attribute list.

+   */

+  bool get_attrib(Dwarf_At at, DIEAttrib* attr) const;

+

+  /* Gets the leaf DIE object containing given address.

+   * See DwarfCU::get_leaf_die_for_address() for method details.

+   * See DIEObject::contains_address() for implementation details.

+   */

+  DIEObject* get_leaf_for_address(Elf_Xword address);

+

+  /* Finds a DIE object for the given die in the branch starting with

+   * this DIE object.

+   */

+  DIEObject* find_die_object(const Dwarf_DIE* die_to_find);

+

+  /* Dumps this object to stdout.

+   * Param:

+   *  only_this - If true, only this object will be dumped. If this parameter

+   *    is false, all the childs and siblings of this object will be dumped

+   *    along with this object.

+   */

+  void dump(bool only_this) const;

+

+ protected:

+  /* Checks if this DIE object containing given address.

+   * Template param:

+   *  AddrType - Type of compilation unin address (4, or 8 bytes), defined by

+   *    address_size field of the CU header. Must be Elf_Xword for 8 bytes

+   *    address, or Elf_Word for 4 bytes address.

+   * Param:

+   *  address - Address ti check.

+   * Return:

+   *  True, if this DIE address ranges (including low_pc, high_pc attributes)

+   *  contain given address, or false otherwise.

+   */

+  template <typename AddrType>

+  bool contains_address(Elf_Xword address);

+

+  /* Advances to the DIE's property list.

+   * Param:

+   *  at_abbr - Upon successful return contains a pointer to the beginning of

+   *    DIE attribute abbreviation list. This parameter can be NULL, if the

+   *    caller is not interested in attribute abbreviation list for this DIE.

+   *  tag - Upon successful return contains DIE's tag. This parameter can be

+   *    NULL, if the caller is not interested in the tag value for this DIE.

+   * Return:

+   *  Pointer to the beginning of the DIE attribute list in mapped .debug_info

+   *  section on success, or NULL on failure.

+   */

+  const Elf_Byte* advance(const Dwarf_Abbr_AT** at_abbr, Dwarf_Tag* tag) const;

+

+ public:

+  /* Gets DIE represented with this instance. */

+  const Dwarf_DIE* die() const {

+    return die_;

+  }

+

+  /* Gets compilation unit this DIE belongs to. */

+  DwarfCU* parent_cu() const {

+    return parent_cu_;

+  }

+

+  /* Gets parent DIE object for this die. */

+  DIEObject* parent_die() const {

+    return parent_die_;

+  }

+

+  /* Gets last child object in the list of this DIE's childs. NOTE: for better

+   * performace the list is created in reverse order (relatively to the order,

+   * in which children DIEs have been discovered).

+   */

+  DIEObject* last_child() const {

+    return last_child_;

+  }

+

+  /* Links next child to the list of this DIE childs. */

+  void link_child(DIEObject* child) {

+    last_child_ = child;

+  }

+

+  /* Gets previous sibling of this DIE in the parent's DIE object list. */

+  DIEObject* prev_sibling() const {

+    return prev_sibling_;

+  }

+

+  /* Links next sibling to the list of this DIE siblings. */

+  void link_sibling(DIEObject* sibl) {

+    prev_sibling_ = sibl;

+  }

+

+  /* Checks if this DIE object represents a CU DIE.

+   * We relay here on the fact that only CU DIE objects have no parent

+   * DIE objects.

+   */

+  bool is_cu_die() const {

+    return parent_die_ == NULL;

+  }

+

+  /* Gets this DIE level in the branch.

+   * DIE level defines DIE's distance from the CU DIE in the branch this DIE

+   * belongs to. In other words, DIE level defines how many parent DIEs exist

+   * between this DIE, and the CU DIE. For instance, the CU DIE has level 0,

+   * a subroutine a() in this compilation unit has level 1, a soubroutine b(),

+   * that has been inlined into subroutine a() will have level 2, a try/catch

+   * block in the inlined subroutine b() will have level 3, and so on.

+   */

+  Elf_Word get_level() const {

+    return parent_die_ != NULL ? parent_die_->get_level() + 1 : 0;

+  }

+

+ protected:

+  /* DIE that is represented with this instance. */

+  const Dwarf_DIE*  die_;

+

+  /* Compilation unit this DIE belongs to. */

+  DwarfCU*          parent_cu_;

+

+  /* Parent DIE object for this die. */

+  DIEObject*        parent_die_;

+

+  /* Last child object in the list of this DIE's childs. NOTE: for better

+   * performace the list is created in reverse order (relatively to the order,

+   * in which children DIEs have been discovered).

+   */

+  DIEObject*        last_child_;

+

+  /* Previous sibling of this DIE in the parent's DIE object list. */

+  DIEObject*        prev_sibling_;

+};

+

+#endif  // ELFF_DWARF_DIE_H_