Just to be clear, I am always referring to the standard C assert() function/macro.
Not the unconditional NuttX ASSERT() macro. Notice the capitalization! (Which is another confusing point worth improving... +1 for NX_ASSERT() ) On Wed, Jan 3, 2024 at 7:32 PM Fotis Panagiotopoulos <f.j.pa...@gmail.com> wrote: > I am sorry, but I still don't see the difference. > > See this line here: > https://github.com/apache/nuttx/blob/master/include/assert.h#L119 > > When NDEBUG is defined, assert also compiles to nothing. > As it ought to do. > > (NDEBUG definition is also controlled by Kconfig, with CONFIG_NDEBUG) > > So, is there an actual difference that I currently have overseen? > > On Wed, Jan 3, 2024 at 6:54 PM Tomek CEDRO <to...@cedro.info> wrote: > >> +1 :-) >> >> -- >> CeDeROM, SQ7MHZ, http://www.tomek.cedro.info >> >> On Wed, Jan 3, 2024, 17:44 Gregory Nutt <spudan...@gmail.com> wrote: >> >> > +1 >> > >> > On 1/3/2024 10:43 AM, Nathan Hartman wrote: >> > > On Wed, Jan 3, 2024 at 11:22 AM Gregory Nutt <spudan...@gmail.com> >> > wrote: >> > >> On 1/3/2024 10:11 AM, Fotis Panagiotopoulos wrote: >> > >>>> That would seem a little odd since there was a PR a few years ago >> to >> > >>> change all instances of assert/ASSERT to DEBUGASSERT to save code >> size. >> > >>> >> > >>> How is that so? >> > >>> >> > >>> As I see here: >> > >>> https://github.com/apache/nuttx/blob/master/include/assert.h#L122 >> > >>> assert defined exactly as DEBUGASSERT. >> > >>> >> > >>> There shouldn't be any code size difference at all. >> > >> When CONFIG_DEBUG_ASSERTIONS is not defined, then all occurrences of >> > >> DEBUGASSERT compile to nothing (actually the current version >> compiles to >> > >> an expression that is optimized out): >> > >> >> > >> #undef DEBUGASSERT /* Like ASSERT, but only if >> > >> CONFIG_DEBUG_ASSERTIONS is defined */ >> > >> >> > >> #ifdef CONFIG_DEBUG_ASSERTIONS >> > >> # define DEBUGASSERT(f) _ASSERT(f, __DEBUG_ASSERT_FILE__, >> > >> __DEBUG_ASSERT_LINE__) >> > >> #else >> > >> # define DEBUGASSERT(f) ((void)(1 || (f))) >> > >> #endif >> > >> >> > >> This value, ((void)(1 || (f))), is completely removed by the >> optimizer >> > >> because of short-circuiting and dead code removal. So the code is >> much >> > >> smaller if CONFIG_DEBUG_ASSERTIONS is not enabled. If DEBUGASSERT() >> is >> > >> replaced with assert() than that code bloat would be unconditional, >> > >> although somewhat less than when assertions are enabled. >> > >> >> > >> This same kind of logic also applies to DEBUGPANIC and DEBUGVERIFY. >> > >> >> > >> Xiao Xiang made that change to reduce the size as needed by their >> > >> products. He is the person you should be talking to. >> > > >> > > Maybe we need NX_DEBUGASSERT, NX_DEBUGPANIC, NX_DEBUGVERIFY. The NX >> > > prefix would make it more clear that this is NuttX-specific. These >> > > would be used in the OS only, not in applications, and >> > > CONFIG_DEBUG_ASSERTIONS would continue to control if these are real or >> > > optimized out. >> > > >> > > Applications that need their own specific, Kconfig-controlled debug >> > > assertion, should define one themselves, and their own Kconfig to >> > > optimize it out. Rationale: If you are debugging an application, >> > > enable assertions only in that application, not everywhere throughout >> > > the system. >> > > >> > > Cheers >> > > Nathan >> > >> > >> > >> >
