Silence 64 to 32 bit truncation errors on WTF strings.

strlen returns size_t which can be 64 bits yet all of the WTF strings
use 32 storage lengths. Add a helper function string_unsigned which
returns the strlen with a SafeCast to unsigned. Place it in an
implementation file to avoid increase in binary size due to inlining.

BUG=588506

Change-Id: I3b5025c1fee9b1eda9cd017af6bdfc66d808e802
Reviewed-on: https://chromium-review.googlesource.com/1096133Reviewed-by: Kentaro Hara <haraken@chromium.org>
Reviewed-by: Yuta Kitamura <yutak@chromium.org>
Commit-Queue: Dave Tapuska <dtapuska@chromium.org>
Cr-Commit-Position: refs/heads/master@{#566415}

third_party/blink/renderer/platform/wtf/BUILD.gn

@@ -125,6 +125,7 @@ jumbo_component("wtf") {
     "stack_util.h",
     "static_constructors.h",
     "std_lib_extras.h",
+    "string_extras.cc",
     "string_extras.h",
     "string_hasher.h",
     "terminated_array.h",

third_party/blink/renderer/platform/wtf/string_extras.cc

+// Copyright 2018 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 "third_party/blink/renderer/platform/wtf/string_extras.h"
+
+#include "third_party/blink/renderer/platform/wtf/std_lib_extras.h"
+
+namespace WTF {
+
+unsigned strlen_unsigned(const char* string) {
+  return SafeCast<unsigned>(strlen(string));
+}
+
+}  // namespace WTF

third_party/blink/renderer/platform/wtf/string_extras.h

@@ -28,6 +28,7 @@
 
 #include <string.h>
 #include "build/build_config.h"
+#include "third_party/blink/renderer/platform/wtf/wtf_export.h"
 
 #if defined(OS_POSIX)
 #include <strings.h>
@@ -46,4 +47,11 @@ inline int strcasecmp(const char* s1, const char* s2) {
 
 #endif  // defined(COMPILER_MSVC)
 
+namespace WTF {
+
+// Wrapper around strlen with a SafeCast to unsigned from size_t.
+WTF_EXPORT unsigned strlen_unsigned(const char* string);
+
+}  // namespace WTF
+
 #endif  // THIRD_PARTY_BLINK_RENDERER_PLATFORM_WTF_STRING_EXTRAS_H_

third_party/blink/renderer/platform/wtf/text/atomic_string.h

@@ -27,6 +27,7 @@
 #include "build/build_config.h"
 #include "third_party/blink/renderer/platform/wtf/allocator.h"
 #include "third_party/blink/renderer/platform/wtf/hash_table_deleted_value_type.h"
+#include "third_party/blink/renderer/platform/wtf/string_extras.h"
 #include "third_party/blink/renderer/platform/wtf/text/cstring.h"
 #include "third_party/blink/renderer/platform/wtf/text/string_view.h"
 #include "third_party/blink/renderer/platform/wtf/text/wtf_string.h"
@@ -58,8 +59,9 @@ class WTF_EXPORT AtomicString {
 
   AtomicString() = default;
   AtomicString(const LChar* chars)
-      : AtomicString(chars,
-                     chars ? strlen(reinterpret_cast<const char*>(chars)) : 0) {
+      : AtomicString(
+            chars,
+            chars ? strlen_unsigned(reinterpret_cast<const char*>(chars)) : 0) {
   }
   AtomicString(const char* chars)
       : AtomicString(reinterpret_cast<const LChar*>(chars)) {}

third_party/blink/renderer/platform/wtf/text/string_concatenate.h

@@ -28,6 +28,7 @@
 
 #include <string.h>
 #include "third_party/blink/renderer/platform/wtf/allocator.h"
+#include "third_party/blink/renderer/platform/wtf/string_extras.h"
 
 #ifndef WTFString_h
 #include "third_party/blink/renderer/platform/wtf/text/atomic_string.h"
@@ -101,7 +102,7 @@ class WTF_EXPORT StringTypeAdapter<char*> {
 
  public:
   explicit StringTypeAdapter<char*>(char* buffer)
-      : buffer_(buffer), length_(strlen(buffer)) {}
+      : buffer_(buffer), length_(strlen_unsigned(buffer)) {}
 
   unsigned length() const { return length_; }
   bool Is8Bit() const { return true; }

third_party/blink/renderer/platform/wtf/text/string_hash.h

@@ -24,6 +24,7 @@
 
 #include "third_party/blink/renderer/platform/wtf/allocator.h"
 #include "third_party/blink/renderer/platform/wtf/hash_traits.h"
+#include "third_party/blink/renderer/platform/wtf/string_extras.h"
 #include "third_party/blink/renderer/platform/wtf/string_hasher.h"
 #include "third_party/blink/renderer/platform/wtf/text/atomic_string.h"
 
@@ -102,7 +103,7 @@ class CaseFoldingHash {
 
   static inline unsigned GetHash(const char* data) {
     return CaseFoldingHash::GetHash(reinterpret_cast<const LChar*>(data),
-                                    strlen(data));
+                                    strlen_unsigned(data));
   }
 
   static inline bool Equal(const StringImpl* a, const StringImpl* b) {

third_party/blink/renderer/platform/wtf/text/string_view.h

@@ -11,6 +11,7 @@
 #include "base/memory/scoped_refptr.h"
 #endif
 #include <cstring>
+#include "third_party/blink/renderer/platform/wtf/string_extras.h"
 #include "third_party/blink/renderer/platform/wtf/text/string_impl.h"
 #include "third_party/blink/renderer/platform/wtf/text/unicode.h"
 
@@ -73,7 +74,8 @@ class WTF_EXPORT StringView {
       : StringView(reinterpret_cast<const LChar*>(chars), length) {}
   StringView(const LChar* chars)
       : StringView(chars,
-                   chars ? strlen(reinterpret_cast<const char*>(chars)) : 0) {}
+                   chars ? strlen_unsigned(reinterpret_cast<const char*>(chars))
+                         : 0) {}
   StringView(const char* chars)
       : StringView(reinterpret_cast<const LChar*>(chars)) {}
 

third_party/blink/renderer/platform/wtf/text/wtf_string.h

@@ -30,6 +30,7 @@
 #include "third_party/blink/renderer/platform/wtf/allocator.h"
 #include "third_party/blink/renderer/platform/wtf/compiler.h"
 #include "third_party/blink/renderer/platform/wtf/hash_table_deleted_value_type.h"
+#include "third_party/blink/renderer/platform/wtf/string_extras.h"
 #include "third_party/blink/renderer/platform/wtf/text/ascii_fast_path.h"
 #include "third_party/blink/renderer/platform/wtf/text/string_impl.h"
 #include "third_party/blink/renderer/platform/wtf/text/string_view.h"
@@ -92,7 +93,7 @@ class WTF_EXPORT String {
   String(const LChar* characters)
       : String(reinterpret_cast<const char*>(characters)) {}
   String(const char* characters)
-      : String(characters, characters ? strlen(characters) : 0) {}
+      : String(characters, characters ? strlen_unsigned(characters) : 0) {}
 
   // Construct a string referencing an existing StringImpl.
   String(StringImpl* impl) : impl_(impl) {}