Create builds configured for ARM and AARCH64.

tools/relocation_packer/src/run_length_encoder.cc

 // Copyright 2014 The Chromium Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-// TODO(simonb): Extend for 64-bit target libraries.
-
 #include "run_length_encoder.h"
 
-#include <string.h>
-#include <string>
 #include <vector>
 
 #include "debug.h"
+#include "elf_traits.h"
 
 namespace relocation_packer {
 
 namespace {
 
 // Generate a vector of deltas between the r_offset fields of adjacent
-// R_ARM_RELATIVE relocations.
-void GetDeltas(const std::vector<Elf32_Rel>& relocations,
-               std::vector<Elf32_Addr>* deltas) {
+// ARM relative relocations.
+void GetDeltas(const std::vector<ELF::Rel>& relocations,
+               std::vector<ELF::Addr>* deltas) {
   CHECK(relocations.size() >= 2);
 
   for (size_t i = 0; i < relocations.size() - 1; ++i) {
-    const Elf32_Addr first = relocations[i].r_offset;
-    const Elf32_Addr second = relocations[i + 1].r_offset;
+    const ELF::Addr first = relocations[i].r_offset;
+    const ELF::Addr second = relocations[i + 1].r_offset;
     // Requires that offsets are 'strictly increasing'.  The packing
     // algorithm fails if this does not hold.
     CHECK(second > first);
     deltas->push_back(second - first);
   }
 }
 
 // Condense a set of r_offset deltas into a run-length encoded packing.
 // Represented as count-delta pairs, where count is the run length and
 // delta the common difference between adjacent r_offsets.
-void Condense(const std::vector<Elf32_Addr>& deltas,
-              std::vector<Elf32_Word>* packed) {
+void Condense(const std::vector<ELF::Addr>& deltas,
+              std::vector<ELF::Xword>* packed) {
   CHECK(!deltas.empty());
   size_t count = 0;
-  Elf32_Addr current = deltas[0];
+  ELF::Addr current = deltas[0];
 
   // Identify spans of identically valued deltas.
   for (size_t i = 0; i < deltas.size(); ++i) {
-    const Elf32_Addr delta = deltas[i];
+    const ELF::Addr delta = deltas[i];
     if (delta == current) {
       count++;
     } else {
       // We reached the end of a span of identically valued deltas.
       packed->push_back(count);
       packed->push_back(current);
       current = delta;
       count = 1;
     }
   }
 
   // Write the final span.
   packed->push_back(count);
   packed->push_back(current);
 }
 
 // Uncondense a set of r_offset deltas from a run-length encoded packing.
 // The initial address for uncondensing, the start index for the first
 // condensed slot in packed, and the count of pairs are provided.
-void Uncondense(Elf32_Addr addr,
-                const std::vector<Elf32_Word>& packed,
+void Uncondense(ELF::Addr addr,
+                const std::vector<ELF::Xword>& packed,
                 size_t start_index,
                 size_t end_index,
-                std::vector<Elf32_Rel>* relocations) {
+                std::vector<ELF::Rel>* relocations) {
   // The first relocation is just one created from the initial address.
-  const Elf32_Rel initial = {addr, R_ARM_RELATIVE};
+  ELF::Rel initial;
+  initial.r_offset = addr;
+  initial.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode);
   relocations->push_back(initial);
 
   // Read each count and delta pair, beginning at the start index and
   // finishing at the end index.
   for (size_t i = start_index; i < end_index; i += 2) {
     size_t count = packed[i];
-    const Elf32_Addr delta = packed[i + 1];
+    const ELF::Addr delta = packed[i + 1];
     CHECK(count > 0 && delta > 0);
 
     // Generate relocations for this count and delta pair.
     while (count) {
       addr += delta;
-      const Elf32_Rel relocation = {addr, R_ARM_RELATIVE};
+      ELF::Rel relocation;
+      relocation.r_offset = addr;
+      relocation.r_info = ELF_R_INFO(0, ELF::kRelativeRelocationCode);
       relocations->push_back(relocation);
       count--;
     }
   }
 }
 
 }  // namespace
 
-// Encode R_ARM_RELATIVE relocations into a run-length encoded (packed)
+// Encode ARM relative relocations into a run-length encoded (packed)
 // representation.
-void RelocationRunLengthCodec::Encode(const std::vector<Elf32_Rel>& relocations,
-                                      std::vector<Elf32_Word>* packed) {
+void RelocationRunLengthCodec::Encode(const std::vector<ELF::Rel>& relocations,
+                                      std::vector<ELF::Xword>* packed) {
   // If we have zero or one relocation only then there is no packing
   // possible; a run-length encoding needs a run.
   if (relocations.size() < 2)
     return;
 
-  std::vector<Elf32_Addr> deltas;
+  std::vector<ELF::Addr> deltas;
   GetDeltas(relocations, &deltas);
 
   // Reserve space for the element count.
   packed->push_back(0);
 
   // Initialize the packed data with the first offset, then follow up with
   // the condensed deltas vector.
   packed->push_back(relocations[0].r_offset);
   Condense(deltas, packed);
 
   // Fill in the packed pair count.
   packed->at(0) = (packed->size() - 2) >> 1;
 }
 
-// Decode R_ARM_RELATIVE reloctions from a run-length encoded (packed)
+// Decode ARM relative relocations from a run-length encoded (packed)
 // representation.
-void RelocationRunLengthCodec::Decode(const std::vector<Elf32_Word>& packed,
-                                      std::vector<Elf32_Rel>* relocations) {
-  // We need at least one packed pair after the packed pair count to be
-  // able to unpack.
-  if (packed.size() < 3)
+void RelocationRunLengthCodec::Decode(const std::vector<ELF::Xword>& packed,
+                                      std::vector<ELF::Rel>* relocations) {
+  // We need at least one packed pair after the packed pair count and start
+  // address to be able to unpack.
+  if (packed.size() < 4)
     return;
 
   // Ensure that the packed data offers enough pairs.  There may be zero
   // padding on it that we ignore.
   CHECK(packed[0] <= (packed.size() - 2) >> 1);
 
   // The first packed vector element is the pairs count and the second the
   // initial address.  Start uncondensing pairs at the third, and finish
   // at the end of the pairs data.
   const size_t pairs_count = packed[0];
-  const Elf32_Addr addr = packed[1];
+  const ELF::Addr addr = packed[1];
   Uncondense(addr, packed, 2, 2 + (pairs_count << 1), relocations);
 }
 
 }  // namespace relocation_packer