[tenfingers]

The number of warnings that GCC can generate can cover some very speculative grounds, which are sometimes legitimate code. In fact many C idioms that were considered commonplace are now "warnings" because of the subtle semantics.

Take assignment/evaluation in a condition:

  if(a = [expr])

was not so frowned upon before, because it was sort of implicit that "a" was also needed in the nested block that followed. Now it's a warning without a double parenthesis, because it's also common the typo of using = instead of ==.

The list goes on and on. In fact, the level of diagnostics that you get in C is pretty bit, and probably one of the best in class compared to any other language thanks to the maturity of the toolchain.