Cloning a bunch of stuff from the native_client repository at r6528

ppapi/native_client/src/shared/ppapi_proxy/utility.cc

+/*
+ * Copyright (c) 2011 The Native Client 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 "native_client/src/shared/ppapi_proxy/utility.h"
+
+#include <stdarg.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include "native_client/src/shared/platform/nacl_check.h"
+#include "native_client/src/include/nacl_assert.h"
+
+namespace ppapi_proxy {
+
+const int foo = 5;
+
+void DebugPrintf(const char* format, ...) {
+  static bool printf_enabled = (getenv("NACL_PPAPI_PROXY_DEBUG") != NULL);
+  if (printf_enabled) {
+    va_list argptr;
+    va_start(argptr, format);
+#ifdef __native_client__
+    fprintf(stdout, "PPAPI_PROXY_PLUGIN : ");
+#else
+    fprintf(stdout, "PPAPI_PROXY_BROWSER: ");
+#endif
+    vfprintf(stdout, format, argptr);
+    va_end(argptr);
+    fflush(stdout);
+  }
+}
+
+bool StringIsUtf8(const char* data, uint32_t len) {
+  for (uint32_t i = 0; i < len; i++) {
+    if ((data[i] & 0x80) == 0) {
+      // Single-byte symbol.
+      continue;
+    } else if ((data[i] & 0xc0) == 0x80) {
+      // Invalid first byte.
+      DebugPrintf("Invalid first byte %02x\n", data[i]);
+      return false;
+    }
+    // This is a multi-byte symbol.
+    DebugPrintf("Multi-byte %02x\n", data[i]);
+    // Discard the uppermost bit.  The remaining high-order bits are the
+    // unary count of continuation bytes (up to 5 of them).
+    char first = data[i] << 1;
+    uint32_t continuation_bytes = 0;
+    const uint32_t kMaxContinuationBytes = 5;
+    while (first & 0x80) {
+      if (++i >= len) {
+        DebugPrintf("String ended before enough continuation bytes"
+                    "were found.\n");
+        return false;
+      } else if (++continuation_bytes > kMaxContinuationBytes) {
+        DebugPrintf("Too many continuation bytes were requested.\n");
+        return false;
+      } else if ((data[i] & 0xc0) != 0x80) {
+        DebugPrintf("Invalid continuation byte.\n");
+        return false;
+      }
+      first <<= 1;
+    }
+  }
+  return true;
+}
+
+}  // namespace ppapi_proxy