On Wed, 2020-06-17 at 08:54 -0400, Tony Camuso wrote: > Sorry for the noise, if this has already been reported or corrected. > > tboot is built with the -Wextra Cflag, which is an alias for a > collection of warning flags. tboot's make interprets warnings as errors. > > From GCC 7 forward, the -Wextra Cflag includes -Wimplicit-fallthrough. > > The GCC 7+ switch statement requires a break statement after each case. > Without a break statement after a case, then an "implicit fallthrough" > condition exists, where the matched case is executed, and the following > case is also executed. If none of the fallthrough cases has a statement, > and if the last statement in the fallthrough cascade is a break, all is > forgiven, and the GCC 7+ compiler will move on. > > Otherwise, GCC 7+ with -Wextra will issue the following error when > -Werror is set, as it is in the tboot make. > > error: this statement may fall through [-Werror=implicit-fallthrough=] > > That means case statements with implicit fallthroughs will be flagged > as compile errors and crater the build. There exists a number of > compiler specific ways to tell the compiler that the fallthrough is > there by design, but the simplest way to avert this problem is to add > the -Wno-implicit-fallthrough flag to the CFLAGS_WARN variable in tboot's > Config.mk file. >
Hi Tony Thank you for your patch. This is already fixed in a6180f9e9e86. In general we want to have -Wimplicit-fallthrough enabled, however there was a bug where different CFLAGS value was passed to safestringlib Makefile depends on building environment. Sometimes safestringlib was build with -Werror -Wextra, sometimes not. [1] Could you please check if with that commit you can build TBOOT without errors? [1] https://sourceforge.net/p/tboot/mailman/message/37005286/ Thanks, Lukasz _______________________________________________ tboot-devel mailing list tboot-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/tboot-devel
