Refactor rel32 searching process for x64 to make it more similar to x86.

courgette/rel32_finder_win32_x86.cc

Index: courgette/rel32_finder_win32_x86.cc
diff --git a/courgette/rel32_finder_win32_x86.cc b/courgette/rel32_finder_win32_x86.cc
deleted file mode 100644
index 61ff9696d5ac19174d514c8930111e64c326342e..0000000000000000000000000000000000000000
--- a/courgette/rel32_finder_win32_x86.cc
+++ /dev/null
@@ -1,113 +0,0 @@
-// Copyright 2015 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.
-
-#include <stdint.h>
-
-#include "courgette/rel32_finder_win32_x86.h"
-
-namespace courgette {
-
-Rel32FinderWin32X86::Rel32FinderWin32X86(RVA relocs_start_rva,
-                                         RVA relocs_end_rva)
-    : relocs_start_rva_(relocs_start_rva), relocs_end_rva_(relocs_end_rva) {
-}
-
-Rel32FinderWin32X86::~Rel32FinderWin32X86() {
-}
-
-void Rel32FinderWin32X86::SwapRel32Locations(std::vector<RVA>* dest) {
-  dest->swap(rel32_locations_);
-}
-
-#if COURGETTE_HISTOGRAM_TARGETS
-void Rel32FinderWin32X86::SwapRel32TargetRVAs(std::map<RVA, int>* dest) {
-  dest->swap(rel32_target_rvas_);
-}
-#endif
-
-Rel32FinderWin32X86_Basic::Rel32FinderWin32X86_Basic(RVA relocs_start_rva,
-                                                     RVA relocs_end_rva)
-    : Rel32FinderWin32X86(relocs_start_rva, relocs_end_rva) {
-}
-
-Rel32FinderWin32X86_Basic::~Rel32FinderWin32X86_Basic() {
-}
-
-void Rel32FinderWin32X86_Basic::Find(const uint8_t* start_pointer,
-                                     const uint8_t* end_pointer,
-                                     RVA start_rva,
-                                     RVA end_rva,
-                                     const std::vector<RVA>& abs32_locations) {
-  // Quick way to convert from Pointer to RVA within a single Section is to
-  // subtract 'pointer_to_rva'.
-  const uint8_t* const adjust_pointer_to_rva = start_pointer - start_rva;
-
-  std::vector<RVA>::const_iterator abs32_pos = abs32_locations.begin();
-
-  // Find the rel32 relocations.
-  const uint8_t* p = start_pointer;
-  while (p < end_pointer) {
-    RVA current_rva = static_cast<RVA>(p - adjust_pointer_to_rva);
-
-    // Skip the base reloation table if we encounter it.
-    // Note: We're not bothering to handle the edge case where a Rel32 pointer
-    // collides with |relocs_start_rva_| by being {1, 2, 3}-bytes before it.
-    if (current_rva == relocs_start_rva_) {
-      if (relocs_start_rva_ < relocs_end_rva_) {
-        p += relocs_end_rva_ - relocs_start_rva_;
-        continue;
-      }
-    }
-
-    // Heuristic discovery of rel32 locations in instruction stream: are the
-    // next few bytes the start of an instruction containing a rel32
-    // addressing mode?
-    const uint8_t* rel32 = nullptr;
-
-    if (p + 5 <= end_pointer) {
-      if (*p == 0xE8 || *p == 0xE9) {  // jmp rel32 and call rel32
-        rel32 = p + 1;
-      }
-    }
-    if (p + 6 <= end_pointer) {
-      if (*p == 0x0F  &&  (*(p+1) & 0xF0) == 0x80) {  // Jcc long form
-        if (p[1] != 0x8A && p[1] != 0x8B)  // JPE/JPO unlikely
-          rel32 = p + 2;
-      }
-    }
-    if (rel32) {
-      RVA rel32_rva = static_cast<RVA>(rel32 - adjust_pointer_to_rva);
-
-      // Is there an abs32 reloc overlapping the candidate?
-      while (abs32_pos != abs32_locations.end() && *abs32_pos < rel32_rva - 3)
-        ++abs32_pos;
-      // Now: (*abs32_pos > rel32_rva - 4) i.e. the lowest addressed 4-byte
-      // region that could overlap rel32_rva.
-      if (abs32_pos != abs32_locations.end()) {
-        if (*abs32_pos < rel32_rva + 4) {
-          // Beginning of abs32 reloc is before end of rel32 reloc so they
-          // overlap. Skip four bytes past the abs32 reloc.
-          p += (*abs32_pos + 4) - current_rva;
-          continue;
-        }
-      }
-
-      // + 4 since offset is relative to start of next instruction.
-      RVA target_rva = rel32_rva + 4 + Read32LittleEndian(rel32);
-      // Valid, rel32 target must be within image, and within this section.
-      // Subsumes |target_rva| != |kUnassignedRVA|.
-      if (start_rva <= target_rva && target_rva < end_rva) {
-        rel32_locations_.push_back(rel32_rva);
-#if COURGETTE_HISTOGRAM_TARGETS
-        ++rel32_target_rvas_[target_rva];
-#endif
-        p = rel32 + 4;
-        continue;
-      }
-    }
-    p += 1;
-  }
-}
-
-}  // namespace courgette