This patch adds a new third-party library that implements an ELF dynamic linker.

third_party/crazy_linker/crazy_linker/src/crazy_linker_line_reader.cpp

Index: third_party/crazy_linker/crazy_linker/src/crazy_linker_line_reader.cpp
diff --git a/third_party/crazy_linker/crazy_linker/src/crazy_linker_line_reader.cpp b/third_party/crazy_linker/crazy_linker/src/crazy_linker_line_reader.cpp
new file mode 100644
index 0000000000000000000000000000000000000000..eedd2c82c62ab86cc36a929171d0a0fa7238da3a
--- /dev/null
+++ b/third_party/crazy_linker/crazy_linker/src/crazy_linker_line_reader.cpp
@@ -0,0 +1,127 @@
+// Copyright (c) 2013 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 "crazy_linker_line_reader.h"
+
+#include "crazy_linker_debug.h"
+
+// Set to 1 to enable debug logs here.
+#define DEBUG_LINE_READER 0
+
+#define LLOG(...)  LOG_IF(DEBUG_LINE_READER, __VA_ARGS__)
+
+namespace crazy {
+
+LineReader::LineReader() : fd_(), buff_(buff0_) {
+  Reset();
+  eof_ = true;
+}
+
+LineReader::LineReader(const char* path) : fd_(), buff_(buff0_) {
+  Open(path);
+}
+
+LineReader::~LineReader() {
+  Reset();
+}
+
+void LineReader::Open(const char* path) {
+  Reset();
+  eof_ = !fd_.OpenReadOnly(path);
+}
+
+void LineReader::Reset() {
+  if (buff_ != buff0_)
+    ::free(buff_);
+
+  eof_ = false;
+  line_start_ = 0;
+  line_len_ = 0;
+  buff_size_ = 0;
+  buff_capacity_ = sizeof buff0_;
+  buff_ = buff0_;
+}
+
+bool LineReader::GetNextLine() {
+  // Eat previous line.
+  line_start_ += line_len_;
+  line_len_ = 0;
+
+  for (;;) {
+    LLOG("%s: LOOP line_start=%d buff_size=%d buff_capacity=%d\n",
+         __FUNCTION__, line_start_, buff_size_, buff_capacity_);
+
+    // Find the end of the current line in the current buffer.
+    const char* line = buff_ + line_start_;
+    const char* line_end = reinterpret_cast<const char*>(
+        ::memchr(line, '\n', buff_size_ - line_start_));
+    if (line_end != NULL) {
+      // Found one, return it directly.
+      line_len_ = static_cast<size_t>(line_end + 1 - line);
+      LLOG("%s: LINE line_start=%d line_len=%d '%.*s'\n",
+           __FUNCTION__, line_start_, line_len_, line_len_,
+           buff_ + line_start_);
+      return true;
+    }
+
+    // Eat the start of the buffer
+    if (line_start_ > 0) {
+      ::memmove(buff_, buff_ + line_start_, buff_size_ - line_start_);
+      buff_size_ -= line_start_;
+      line_start_ = 0;
+      LLOG("%s: MOVE buff_size=%d\n", __FUNCTION__, buff_size_);
+    }
+
+    // Handle end of input now.
+    if (eof_) {
+      // If there is a last line that isn't terminated by a newline, and
+      // there is room for it in the buffer. Manually add a \n and return
+      // the line.
+      if (buff_size_ > 0 && buff_size_ < buff_capacity_) {
+        buff_[buff_size_++] = '\n';
+        line_len_ = buff_size_;
+        LLOG("%s: EOF_LINE buff_size=%d '%.*s'\n",
+             __FUNCTION__, buff_size_, buff_size_, buff_);
+        return true;
+      }
+      // Otherwise, ignore the last line.
+      LLOG("%s: EOF\n", __FUNCTION__);
+      return false;
+    }
+
+    // Before reading more data, grow the buffer if needed.
+    if (buff_size_ == buff_capacity_) {
+      size_t new_capacity = buff_capacity_ * 2;
+      void* old_buff = (buff_ == buff0_) ? NULL : buff_;
+      buff_ = static_cast<char*>(::realloc(old_buff, new_capacity));
+      if (old_buff != buff_)
+        ::memcpy(buff_, buff0_, buff_capacity_);
+
+      buff_capacity_ = new_capacity;
+      LLOG("%s: GROW buff_size=%d buff_capacity=%d '%.*s'\n",
+           __FUNCTION__, buff_size_, buff_capacity_, buff_size_, buff_);
+    }
+
+    // Try to fill the rest of buffer after current content.
+    size_t avail = buff_capacity_ - buff_size_;
+    int ret = fd_.Read(buff_ + buff_size_, avail);
+    LLOG("%s: READ buff_size=%d buff_capacity=%d avail=%d ret=%d\n",
+         __FUNCTION__, buff_size_, buff_capacity_, avail, ret);
+    if (ret <= 0) {
+      eof_ = true;
+      ret = 0;
+    }
+    buff_size_ += static_cast<size_t>(ret);
+  }
+}
+
+const char* LineReader::line() const {
+  return buff_ + line_start_;
+}
+
+size_t LineReader::length() const {
+  return line_len_;
+}
+
+}  // namespace crazy