The fact that GCC issues a warning usually has nothing to do with whether the construct is legal C, but whether the GCC developers consider it either a likely indication that you meant something other than what you write, or just bad style. Here are some examples: if (x = 0) — you almost surely … Read more
You should remove the braces: { and } around single values. struct TECH lut_model_1[2] = {{296.001465, 74.216972, 2.025908, 1.516384, 1, {0.001746, 0.000256, 0.006216, 0.005249, -0.001668, -0.001377, 0.009865, 0.010454, -0.000288, -0.005853, 0.010584, 0.015440, 0.000465, -0.000602, 0.004330, 0.005700, 0.017120, 0.233015, 0.034154, 0.244022, 0.007644, 0.385683, 0.042960, 0.406633, -0.007811, 0.346931, 0.040123, 0.387361, 0.007030, 0.225309, 0.017897, 0.241024, 0.003700, 0.103601, 0.060748, … Read more
Forget casts. Use memcpy. float xhalf = 0.5f*x; uint32_t i; assert(sizeof(x) == sizeof(i)); std::memcpy(&i, &x, sizeof(i)); i = 0x5f375a86 – (i>>1); std::memcpy(&x, &i, sizeof(i)); x = x*(1.5f – xhalf*x*x); return x; The original code tries to initialize the int32_t by first accessing the float object through an int32_t pointer, which is where the rules are … Read more
Use __attribute__ ((fallthrough)) switch (condition) { case 1: printf(“1 “); __attribute__ ((fallthrough)); case 2: printf(“2 “); __attribute__ ((fallthrough)); case 3: printf(“3\n”); break; }
This is GCC bug # 53119: http://gcc.gnu.org/bugzilla/show_bug.cgi?id=53119 If you want to see it fixed, post a followup to the bug report indicating that it’s a problem for you.
Well, first of all, deleting a derived object through a base pointer when the base class does not have a virtual destructor is undefined behavior. Compilers are not required to diagnose undefined behavior… That being said, the reason why this warning does not appear when using std::unique_ptr is most likely due to the fact that … Read more
There was no long long type yet in ISO C90 and C++98. It has only been added in ISO C99 and C++11. GCC provided it as an extension prior to standardization, though.
A quick hacky fix might just to cast to long instead of int. On a lot of systems, sizeof(long) == sizeof(void *). A better idea might be to use intptr_t. int threadnumber = (intptr_t) param; and pthread_create(&(tid[i]), &attr, runner, (void *)(intptr_t)i);
I’m not sure what the correct warning is, but once you’ve found it, you can change its disposition with the following (using ‘format’ as the example): #pragma GCC diagnostic error “-Wformat” Or as strager points out: gcc -Werror=format … I’ve checked the gcc source for this and this specific warning cannot be disabled via command … Read more
I believe this could be the case here: in the first code, GCC notices that you don’t need the entire char array at all, just b[9], so it can replace the code with char b_9; // = ??? printf(“b[9] = %d\n”, b_9); Now, this is a completely legal transform, because as the array was accessed … Read more