Bug 139222 – Fix cast-align warning in StringImpl.h

• Component: New Bugs
• Status: RESOLVED FIXED

[Csaba Osztrogonác]

Fix cast-align warning in StringImpl.h

[Csaba Osztrogonác]

warning log on ARM Linux build:

../../Source/WTF/wtf/text/StringImpl.h: In instantiation of ‘T* WTF::StringImpl::tailPointer() [with T = short unsigned int]’:
../../Source/WTF/wtf/text/StringImpl.h:182:39:   required from here
../../Source/WTF/wtf/text/StringImpl.h:749:87: warning: cast from ‘uint8_t* {aka unsigned char*}’ to ‘short unsigned int*’ increases required alignment of target type [-Wcast-align]
         return reinterpret_cast_ptr<T*>(reinterpret_cast<uint8_t*>(this) + tailOffset<T>());
                                                                                       ^
../../Source/WTF/wtf/text/StringImpl.h: In instantiation of ‘const T* WTF::StringImpl::tailPointer() const [with T = short unsigned int]’:
../../Source/WTF/wtf/text/StringImpl.h:720:47:   required from here
../../Source/WTF/wtf/text/StringImpl.h:743:99: warning: cast from ‘const uint8_t* {aka const unsigned char*}’ to ‘const short unsigned int*’ increases required alignment of target type [-Wcast-align]
         return reinterpret_cast_ptr<const T*>(reinterpret_cast<const uint8_t*>(this) + tailOffset<T>());
                                                                                                   ^
../../Source/WTF/wtf/text/StringImpl.h: In instantiation of ‘const T* WTF::StringImpl::tailPointer() const [with T = WTF::StringImpl*]’:
../../Source/WTF/wtf/text/StringImpl.h:756:42:   required from here
../../Source/WTF/wtf/text/StringImpl.h:743:99: warning: cast from ‘const uint8_t* {aka const unsigned char*}’ to ‘WTF::StringImpl* const*’ increases required alignment of target type [-Wcast-align]
../../Source/WTF/wtf/text/StringImpl.h: In instantiation of ‘T* WTF::StringImpl::tailPointer() [with T = WTF::StringImpl*]’:
../../Source/WTF/wtf/text/StringImpl.h:763:42:   required from here
../../Source/WTF/wtf/text/StringImpl.h:749:87: warning: cast from ‘uint8_t* {aka unsigned char*}’ to ‘WTF::StringImpl**’ increases required alignment of target type [-Wcast-align]
         return reinterpret_cast_ptr<T*>(reinterpret_cast<uint8_t*>(this) + tailOffset<T>());
                                                                                       ^


These casts are safe, tailOffset guarantees the alignment.

[Csaba Osztrogonác]

cc-ing Anders and Andreas, because https://trac.webkit.org/changeset/163341
touched these lines last time.

[Csaba Osztrogonác]

Created attachment 242490 [details]
Patch

[WebKit Commit Bot]

Comment on attachment 242490 [details]
Patch

Clearing flags on attachment: 242490

Committed r176805: <http://trac.webkit.org/changeset/176805>

[WebKit Commit Bot]

All reviewed patches have been landed.  Closing bug.