Hello: ----- 元のメッセージ ----- > 差出人: "Orcan Ogetbil" > 宛先: "RPM Fusion developers discussion list" > Cc: kaffeine-owner(a)rpmfusion.org > 送信済み: 2016年6月29日, 水曜日 11:43:39 > 件名: Re: [kaffeine] Patch for gcc6 and cmake changes > > On 27 June 2016 at 02:57, Leigh Scott wrote: > > commit ed8b668fc05a7f626d5d34e779f58be200b7884c > > Author: leigh123linux > > Date: Mon Jun 27 07:57:17 2016 +0100 > > > +- char cmd[] = { 0xe0, 0x31, 0x6b, config->lnbNumber }; > > ++ char cmd[] = { char(0xe0), 0x31, 0x6b, > > char(config->lnbNumber) }; > > Hi, this looks like a compiler bug to me. I don't see anything > ambiguous in the first line. Are we sure the compilation error is the > intended behavior? > > Thanks, > Orcan > I guess kaffeine is C++ and converting 0xe0 (this is (int)224) to char is narrowing conversion, and implicit narrowing conversion on array initialization is forbidden with gcc6 (i.e. C++14), so now gcc now makes the original error. Regards, Mamoru

Hello, again: > 差出人: "Orcan Ogetbil" > On 29 June 2016 at 00:10, Mamoru TASAKA wrote: > > Hello: > >> 差出人: "Orcan Ogetbil" > >> On 27 June 2016 at 02:57, Leigh Scott wrote: > >> > commit ed8b668fc05a7f626d5d34e779f58be200b7884c > >> > Author: leigh123linux > >> > Date: Mon Jun 27 07:57:17 2016 +0100 > >> > >> > +- char cmd[] = { 0xe0, 0x31, 0x6b, config->lnbNumber }; > >> > ++ char cmd[] = { char(0xe0), 0x31, 0x6b, > >> > char(config->lnbNumber) }; > >> > >> Hi, this looks like a compiler bug to me. I don't see anything > >> ambiguous in the first line. Are we sure the compilation error is the > >> intended behavior? > >> > >> Thanks, > >> Orcan > >> > > > > I guess kaffeine is C++ and converting 0xe0 (this is (int)224) to char is > > narrowing conversion, and implicit narrowing conversion on array > > initialization > > is forbidden with gcc6 (i.e. C++14), so now gcc now makes the original > > error. > > I see. That makes sense. But I think the problem is with > config->lnbNumber instead of 0xe0 (I didn't look into the source code, > this is my guess). > The standard [1] says (page 239): > > "A narrowing conversion is an implicit conversion > (7.4) > from an integer type or unscoped enumeration type to an integer type > that cannot represent all the > values of the original type, except where the source is a constant > expression whose value after integral > promotions will fit into the target type." > > Constant int 224 is within range for char as far as I know so it would > fit into char. Thus, if my interpretation is right, it should not be > considered narrowing conversion. Well, "char" is signed by default on x86_64, so char range is -128 <= char <= 127. So (int)224 is out of char range. Note that char is unsigned by default on arm, so char foo[] = {-1, -1}; fails with C++14 on arm (but not on x86_64).