It the first member of your struct has a scalar type, use STRUCTA array[MAX] = {{ 0 }}; If the first member of your struct happens to be another struct object, whose first member has scalar type, then you’ll have to use STRUCTA array[MAX] = {{{ 0 }}}; and so on. Basically, you have to … Read more
request_mem_region tells the kernel that your driver is going to use this range of I/O addresses, which will prevent other drivers to make any overlapping call to the same region through request_mem_region. This mechanism does not do any kind of mapping, it’s a pure reservation mechanism, which relies on the fact that all kernel device … Read more
With code::blocks you can set your command line arguments like this in the menu: Project > Set programs’ arguments… This opens a window where you can insert your parameters.
Any C library which defines a macro named max in its standard headers is broken beyond imagination. Fortunately, an easy workaround if you need to support such platforms is to #undef max (and any other problematic macros it defines) after including the system headers and before any of your own headers/code. Note that everyone else … Read more
Using Matt Joiner’s example: if (b > a) b = a; You could also do the following, without having to dig into assembly code: bool if_else = b > a; b = a * if_else + b * !if_else;
Take a look at -ftrapv and -fwrapv: -ftrapv This option generates traps for signed overflow on addition, subtraction, multiplication operations. -fwrapv This option instructs the compiler to assume that signed arithmetic overflow of addition, subtraction and multiplication wraps around using twos-complement representation. This flag enables some optimizations and disables other. This option is enabled by … Read more
There is no standard library function to do this, but it’s not too hard to roll your own. There is an existing question on SO about doing this that was answered with source code.
fclose requires as its argument a FILE pointer obtained either by fopen, one of the standard streams stdin, stdout, or stderr, or in some other implementation-defined way. A null pointer is not one of these, so the behavior is undefined, just like fclose((FILE *)0xdeadbeef) would be. NULL is not special in C; aside from the … Read more
You can do it two ways: char r = 0, g = 0, b = 0; or char r, g, b; r = g = b = 0;
When a function is prepended with the descriptor __weak it basically means that if you (the coder) do not define it, it is defined here. Let us take a look at my arch-nemesis “HAL_UART_RxCpltCallback()”. This function exists within the HAL of the STM32F4-HAL code base that you can download from ST-Micro. Within the file stm32f4xx_hal_uart.c … Read more