Em Sun, 14 Mar 2021 22:51:41 +0100 Gregor Jasny <gjasny@xxxxxxxxxxxxxx> escreveu: > Hello Hans, > > On 04.03.21 17:25, Gregor Jasny wrote: > > qv4l fails to build with GCC 11: > > https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=984381 > > > > The reason is that min/max are defined as macros here: > > https://git.linuxtv.org/v4l-utils.git/tree/utils/common/v4l2-tpg.patch#n200 > > <https://git.linuxtv.org/v4l-utils.git/tree/utils/common/v4l2-tpg.patch#n200> > > > > should I apply a fix which prefixes the min/max/3 macros with libv4l_? > > Could you please take a look at the patch below and tell me if I should > apply it to v4l-utils master (or of cause, apply it yourself)? > > https://sources.debian.org/patches/v4l-utils/1.20.0-3/fix-gcc-11-ftbfs.diff/ My 2 cents: I don't like the fix: #ifndef libv4l_min #define libv4l_min(a,b) ((a) < (b) ? (a) : (b)) #define libv4l_max(a,b) ((a) > (b) ? (a) : (b)) #endif /* !libv4l_min */ The #ifndef there is useless, as no other includes should ever add it. The culprit here is that the headers are expecting max() and min() to be a macro, but on the build, it is using std::min and std::max functions instead. As v4l2-ctl-common.cpp has: #include <algorithm> This causes a problem. IMHO, the right solution would be to move the #include for it to be at utils/common/v4l2-tpg.h, and replace min/max by std::min/std::max at the headers. Thanks, Mauro
