static in parameter array declarator void f(int a[static 10]); static here is an indication that parameter a is a pointer to int but that the array objet (where a is a pointer to its first element) has at least 10 elements. A compiler has then the right to assume f argument is not NULL and … 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; }
#define IMPLIES(x, y) (!(x) || (y)) #define COMPARE(x, y) (((x) > (y)) – ((x) < (y))) #define SIGN(x) COMPARE(x, 0) #define ARRAY_SIZE(a) (sizeof(a) / sizeof(*a)) #define SWAP(x, y, T) do { T tmp = (x); (x) = (y); (y) = tmp; } while(0) #define SORT2(a, b, T) do { if ((a) > (b)) SWAP((a), (b), … Read more
MSVC is not a C99 compiler, and does not support variable length arrays. At https://learn.microsoft.com/en-us/cpp/c-language/ansi-conformance MSVC is documented as conforming to C90.
After creating a target such as a library or executable, put a line like this in your CMakeLists.txt file: set_property(TARGET tgt PROPERTY C_STANDARD 99) where tgt is the name of your target. I think this was added in CMake 3.1, and the documentation is here: http://www.cmake.org/cmake/help/latest/prop_tgt/C_STANDARD.html If you need to support versions of CMake older … Read more
Go into project properties. Search for C/C++Build -> Settings. In the Tool Settings tab search for GCC C compiler and then Miscellaneous. In other flags text box add the -std=c99. It should work fine.
The three exceptions where an array does not decay into a pointer are the following: Exception 1. — When the array is the operand of sizeof. int main() { int a[10]; printf(“%zu”, sizeof(a)); /* prints 10 * sizeof(int) */ int* p = a; printf(“%zu”, sizeof(p)); /* prints sizeof(int*) */ } Exception 2. — When the … Read more
Include <stdbool.h> header #include <stdbool.h> int main(void){ bool b = false; } Macros true and false expand to 1 and 0 respectively. Section 7.16 Boolean type and values < stdbool.h > 1 The header <stdbool.h> defines four macros. 2 The macro bool expands to _Bool. 3 The remaining three macros are suitable for use in … Read more
I had this problem when I did a global replace of NSLog with DLog. I foolishly included the #define DLog(…) NSLog(… statements, so I ended up with #define DLog(…) DLog(… which caused the warnings, and a linker error.
It seems you might get this problem in case you are using a Windows compiler which uses Microsoft’s non-compliant CRT (non)standard library. That is: Visual Studio or Mingw64/gcc. I can reproduce it on Mingw/gcc. It’s a well-known problem that the Microsoft CRT is broken and for example doesn’t support various format specifiers introduced in C99. … Read more