Having the -Wall flag enabled by default can potentially save lots of time and headaches when
programming in C/C++. Same other usefull flags are :
-Wduplicated-cond: Warn about duplicated condition in if-else-if chains.-Wduplicated-branches: Warn when an if-else has identical branches.-Wlogical-op: Warn about use of logical operations where a bitwise operation probably was intended.-Wnull-dereference: Warn when the compiler detects paths that dereferences a null pointer.-Wjump-misses-init: Warn if a goto statement or a switch statement jumps forward across the initialization of a variable, or jumps backward to a label after the variable has been initialized.