1 files changed, 88 insertions, 0 deletions

diff --git a/gold/layout.h b/gold/layout.h
index ba5fa66..917856e 100644
--- a/gold/layout.h
+++ b/gold/layout.h
@@ -41,6 +41,7 @@ namespace gold
 
 class General_options;
 class Incremental_inputs;
+class Incremental_binary;
 class Input_objects;
 class Mapfile;
 class Symbol_table;
@@ -64,6 +65,69 @@ struct Timespec;
 extern bool
 is_compressed_debug_section(const char* secname);
 
+// Maintain a list of free space within a section, segment, or file.
+// Used for incremental update links.
+
+class Free_list
+{
+ public:
+  Free_list()
+    : list_(), last_remove_(list_.begin()), extend_(false), length_(0)
+  { }
+
+  void
+  init(off_t len, bool extend);
+
+  void
+  remove(off_t start, off_t end);
+
+  off_t
+  allocate(off_t len, uint64_t align, off_t minoff);
+
+  void
+  dump();
+
+  static void
+  print_stats();
+
+ private:
+  struct Free_list_node
+  {
+    Free_list_node(off_t start, off_t end)
+      : start_(start), end_(end)
+    { }
+    off_t start_;
+    off_t end_;
+  };
+  typedef std::list<Free_list_node>::iterator Iterator;
+
+  // The free list.
+  std::list<Free_list_node> list_;
+
+  // The last node visited during a remove operation.
+  Iterator last_remove_;
+
+  // Whether we can extend past the original length.
+  bool extend_;
+
+  // The total length of the section, segment, or file.
+  off_t length_;
+
+  // Statistics:
+  // The total number of free lists used.
+  static unsigned int num_lists;
+  // The total number of free list nodes used.
+  static unsigned int num_nodes;
+  // The total number of calls to Free_list::remove.
+  static unsigned int num_removes;
+  // The total number of nodes visited during calls to Free_list::remove.
+  static unsigned int num_remove_visits;
+  // The total number of calls to Free_list::allocate.
+  static unsigned int num_allocates;
+  // The total number of nodes visited during calls to Free_list::allocate.
+  static unsigned int num_allocate_visits;
+};
+
 // This task function handles mapping the input sections to output
 // sections and laying them out in memory.
 
@@ -401,6 +465,20 @@ class Layout
     delete this->segment_states_;
   }
 
+  // For incremental links, record the base file to be modified.
+  void
+  set_incremental_base(Incremental_binary* base);
+
+  Incremental_binary*
+  incremental_base()
+  { return this->incremental_base_; }
+
+  // For incremental links, record the initial fixed layout of a section
+  // from the base file, and return a pointer to the Output_section.
+  template<int size, bool big_endian>
+  Output_section*
+  init_fixed_output_section(const char*, elfcpp::Shdr<size, big_endian>&);
+
   // Given an input section SHNDX, named NAME, with data in SHDR, from
   // the object file OBJECT, return the output section where this
   // input section should go.  RELOC_SHNDX is the index of a
@@ -414,6 +492,12 @@ class Layout
 	 const char* name, const elfcpp::Shdr<size, big_endian>& shdr,
 	 unsigned int reloc_shndx, unsigned int reloc_type, off_t* offset);
 
+  // For incremental updates, allocate a block of memory from the
+  // free list.  Find a block starting at or after MINOFF.
+  off_t
+  allocate(off_t len, uint64_t align, off_t minoff)
+  { return this->free_list_.allocate(len, align, minoff); }
+
   unsigned int
   find_section_order_index(const std::string&);
 
@@ -1151,6 +1235,10 @@ class Layout
   Unordered_map<std::string, unsigned int> input_section_position_;
   // Vector of glob only patterns in the section_ordering file.
   std::vector<std::string> input_section_glob_;
+  // For incremental links, the base file to be modified.
+  Incremental_binary* incremental_base_;
+  // For incremental links, a list of free space within the file.
+  Free_list free_list_;
 };
 
 // This task handles writing out data in output sections which is not