Bug 197087 – narrowing errors with clang-8.0

• Component: WebCore Misc.
• Status: NEW

[Khem Raj]

Following error is reported by clang on arm

In file included from DerivedSources/WebCore/unified-sources/UnifiedSource-5037b3e8-3.cpp:2:
/mnt/a/yoe/build/tmp/work/cortexa7t2hf-neon-vfpv4-yoe-linux-gnueabi/webkitgtk/2.24.0-r0/webkitgtk-2.24.0/Source/WebCore/contentextensions/NFAToDFA.cpp:352:43: error: non-constant-expression cannot be narrowed from type 'char' to 'signed char' in initializer list [-Wc++11-narrowing]
            dfa.transitionRanges.append({ range.first, range.last });
                                          ^~~~~~~~~~~
/mnt/a/yoe/build/tmp/work/cortexa7t2hf-neon-vfpv4-yoe-linux-gnueabi/webkitgtk/2.24.0-r0/webkitgtk-2.24.0/Source/WebCore/contentextensions/NFAToDFA.cpp:352:43: note: insert an explicit cast to silence this issue
            dfa.transitionRanges.append({ range.first, range.last });
                                          ^~~~~~~~~~~
                                          static_cast<signed char>( )
/mnt/a/yoe/build/tmp/work/cortexa7t2hf-neon-vfpv4-yoe-linux-gnueabi/webkitgtk/2.24.0-r0/webkitgtk-2.24.0/Source/WebCore/contentextensions/NFAToDFA.cpp:352:56: error: non-constant-expression cannot be narrowed from type 'char' to 'signed char' in initializer list [-Wc++11-narrowing]
            dfa.transitionRanges.append({ range.first, range.last });
                                                       ^~~~~~~~~~
/mnt/a/yoe/build/tmp/work/cortexa7t2hf-neon-vfpv4-yoe-linux-gnueabi/webkitgtk/2.24.0-r0/webkitgtk-2.24.0/Source/WebCore/contentextensions/NFAToDFA.cpp:352:56: note: insert an explicit cast to silence this issue
            dfa.transitionRanges.append({ range.first, range.last });
                                                       ^~~~~~~~~~
                                                       static_cast<signed char>( )
2 errors generated.

[Khem Raj]

Created attachment 367781 [details]
proposed fix

[Fujii Hironori]

Did you read this? https://webkit.org/contributing-code/

[Ahmad Saleem]

https://github.com/WebKit/WebKit/blob/256590954964b0f4ead4ad3aa3289bb97bc1f5c4/Source/WebCore/contentextensions/NFAToDFA.cpp#L349

^ Do we need this or we do even have clang 8 supported or we moved to newer version and don't need this?