109004 2013-02-05 20:19:11 -0800 Fix EnumClass so that it can be used with switch statements. 2013-02-05 20:33:13 -0800 1 1 1 Unclassified WebKit Web Template Framework 528+ (Nightly build) Unspecified Unspecified RESOLVED FIXED P2 Normal --- 1 mark.lam mark.lam andersca benjamin ojan.autocc sam webkit.review.bot oldest_to_newest 826045 0 mark.lam 2013-02-05 20:19:11 -0800 When we use the ENUM_CLASS() macro on platforms that don't support C++11 strong enums, ENUM_CLASS will be implemented using the EnumClass template. Currently, if we declare an enum list like this (without C++11 support): ENUM_CLASS(MyEnum) { Enum1, Enum2 } ENUM_CLASS_END(MyEnum); ... and we use it like this: void foo(MyEnum value) { switch(value) { // <========== Compilation error. case Enum1: // do something. case Enum2: // do something else. } } In this example, the switch statement will result in a compilation error. To fix this, EnumClass needs to add a cast operator for Value (where Value is the type of the enumerated values): operator Value() { return m_value; } In addition, we also need to add the following comparison operators: bool operator==(const Value value) { return m_value == value; } bool operator!=(const Value value) { return m_value != value; } bool operator<(const Value value) { return m_value < value; } bool operator<=(const Value value) { return m_value <= value; } bool operator>(const Value value) { return m_value > value; } bool operator>=(const Value value) { return m_value >= value; } Note: the EnumClass template already has comparison operators for comparing against another EnumClass. It also has a conversion constructor that takes a Value argument. The reason for adding these comparison operators that compare against a Value is because when an instance of EnumClass is compared against a Value (or an int), there is an ambiguity in terms of how the C++ compiler can realize that comparison. Here are the 2 ways: 1. Convert the EnumClass to a Value (i.e. int) using the cast operator, and then do an int comparison. 2. Convert the other int value int an EnumClass instance, and then use one of the pre-existing comparison operators to do the comparison. By adding these comparison operators that take a Value argument, we provide an explicit approach to compare between an EnumClass and a Value, and therefore removed the ambiguity above. 826048 1 186751 mark.lam 2013-02-05 20:28:53 -0800 Created attachment 186751 the fix. 826053 2 mark.lam 2013-02-05 20:33:02 -0800 Reviewed by Sam. Landed in r141965: <http://trac.webkit.org/changeset/141965>. 186751 2013-02-05 20:28:53 -0800 2013-02-05 20:28:53 -0800 the fix. bug-109004.patch text/plain 2043 mark.lam SW5kZXg6IFNvdXJjZS9XVEYvQ2hhbmdlTG9nCj09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0tIFNvdXJjZS9XVEYvQ2hh bmdlTG9nCShyZXZpc2lvbiAxNDE5NjMpCisrKyBTb3VyY2UvV1RGL0NoYW5nZUxvZwkod29ya2lu ZyBjb3B5KQpAQCAtMSwzICsxLDIwIEBACisyMDEzLTAyLTA1ICBNYXJrIExhbSAgPG1hcmsubGFt QGFwcGxlLmNvbT4KKworICAgICAgICBGaXggRW51bUNsYXNzIHNvIHRoYXQgaXQgY2FuIGJlIHVz ZWQgd2l0aCBzd2l0Y2ggc3RhdGVtZW50cy4KKyAgICAgICAgaHR0cHM6Ly9idWdzLndlYmtpdC5v cmcvc2hvd19idWcuY2dpP2lkPTEwOTAwNC4KKworICAgICAgICBSZXZpZXdlZCBieSBTYW0gV2Vp bmlnLgorCisgICAgICAgICogd3RmL0VudW1DbGFzcy5oOgorICAgICAgICAoV1RGOjpFbnVtQ2xh c3M6Om9wZXJhdG9yPT0pOgorICAgICAgICAoV1RGOjpFbnVtQ2xhc3M6Om9wZXJhdG9yIT0pOgor ICAgICAgICAoV1RGOjpFbnVtQ2xhc3M6Om9wZXJhdG9yPCk6CisgICAgICAgIChXVEY6OkVudW1D bGFzczo6b3BlcmF0b3I8PSk6CisgICAgICAgIChXVEY6OkVudW1DbGFzczo6b3BlcmF0b3I+KToK KyAgICAgICAgKFdURjo6RW51bUNsYXNzOjpvcGVyYXRvcj49KToKKyAgICAgICAgKEVudW1DbGFz cyk6CisgICAgICAgIChXVEY6OkVudW1DbGFzczo6b3BlcmF0b3IgVmFsdWUpOgorCiAyMDEzLTAy LTA1ICBPbGl2ZXIgSHVudCAgPG9saXZlckBhcHBsZS5jb20+CiAKICAgICAgICAgRGlzYWJsZSBU Q01hbGxvYyBoYXJkZW5pbmcgYXMgaXQncyBicmVha2luZyBsZWFrcy4KSW5kZXg6IFNvdXJjZS9X VEYvd3RmL0VudW1DbGFzcy5oCj09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09PT09 PT09PT09PT09PT09PT09PT09PT09PT09PT09PT0KLS0tIFNvdXJjZS9XVEYvd3RmL0VudW1DbGFz cy5oCShyZXZpc2lvbiAxNDE5NTYpCisrKyBTb3VyY2UvV1RGL3d0Zi9FbnVtQ2xhc3MuaAkod29y a2luZyBjb3B5KQpAQCAtNTQsNiArNTQsNyBAQCBuYW1lc3BhY2UgV1RGIHsKIC8vIE90aGVyd2lz ZSwgaXQgd2lsbCB1c2UgdGhlIEVudW1DbGFzcyB0ZW1wbGF0ZSBiZWxvdy4KIAogI2lmIENPTVBJ TEVSX1NVUFBPUlRTKENYWF9TVFJPTkdfRU5VTVMpCisKICNkZWZpbmUgRU5VTV9DTEFTUyhfX2Vu dW1OYW1lKSBcCiAgICAgZW51bSBjbGFzcyBfX2VudW1OYW1lCiAKQEAgLTEwMCw2ICsxMDEsMTUg QEAgcHVibGljOgogICAgIEFMV0FZU19JTkxJTkUgYm9vbCBvcGVyYXRvcj4oY29uc3QgRW51bUNs YXNzIG90aGVyKSB7IHJldHVybiBtX3ZhbHVlID4gb3RoZXIubV92YWx1ZTsgfQogICAgIEFMV0FZ U19JTkxJTkUgYm9vbCBvcGVyYXRvcj49KGNvbnN0IEVudW1DbGFzcyBvdGhlcikgeyByZXR1cm4g bV92YWx1ZSA+PSBvdGhlci5tX3ZhbHVlOyB9CiAKKyAgICBBTFdBWVNfSU5MSU5FIGJvb2wgb3Bl cmF0b3I9PShjb25zdCBWYWx1ZSB2YWx1ZSkgeyByZXR1cm4gbV92YWx1ZSA9PSB2YWx1ZTsgfQor ICAgIEFMV0FZU19JTkxJTkUgYm9vbCBvcGVyYXRvciE9KGNvbnN0IFZhbHVlIHZhbHVlKSB7IHJl dHVybiBtX3ZhbHVlICE9IHZhbHVlOyB9CisgICAgQUxXQVlTX0lOTElORSBib29sIG9wZXJhdG9y PChjb25zdCBWYWx1ZSB2YWx1ZSkgeyByZXR1cm4gbV92YWx1ZSA8IHZhbHVlOyB9CisgICAgQUxX QVlTX0lOTElORSBib29sIG9wZXJhdG9yPD0oY29uc3QgVmFsdWUgdmFsdWUpIHsgcmV0dXJuIG1f dmFsdWUgPD0gdmFsdWU7IH0KKyAgICBBTFdBWVNfSU5MSU5FIGJvb2wgb3BlcmF0b3I+KGNvbnN0 IFZhbHVlIHZhbHVlKSB7IHJldHVybiBtX3ZhbHVlID4gdmFsdWU7IH0KKyAgICBBTFdBWVNfSU5M SU5FIGJvb2wgb3BlcmF0b3I+PShjb25zdCBWYWx1ZSB2YWx1ZSkgeyByZXR1cm4gbV92YWx1ZSA+ PSB2YWx1ZTsgfQorCisgICAgQUxXQVlTX0lOTElORSBvcGVyYXRvciBWYWx1ZSgpIHsgcmV0dXJu IG1fdmFsdWU7IH0KKwogcHJpdmF0ZToKICAgICBWYWx1ZSBtX3ZhbHVlOwogfTsK