Use strict function prototypes #945

`-Wstrict-prototypes` warn if a function is declared or defined without
specifying the argument types.

This warning disallow function prototypes with empty parameter list.
In C, a function declared with an empty parameter list accepts an
arbitrary number of arguments when being called. This is for historic
reasons; originally, C functions didn't have prototypes, as C evolved
from B, a typeless language. When prototypes were added, the original
typeless declarations were left in the language for backwards
compatibility.
Instead we should provide `void` in argument list to state
that function doesn't have arguments.

Also this warning disallow declaring type of the parameters after the
parentheses because Neovim header generator produce no declarations for
old-stlyle prototypes: it expects to find `{` after prototype.

1 files changed, 2 insertions, 5 deletions

diff --git a/src/nvim/ex_getln.c b/src/nvim/ex_getln.c
index ad0bcdc150..e8e2f61679 100644
--- a/src/nvim/ex_getln.c
+++ b/src/nvim/ex_getln.c
@@ -3932,11 +3932,8 @@ expand_shellcmd (
  * Call "user_expand_func()" to invoke a user defined VimL function and return
  * the result (either a string or a List).
  */
-static void * call_user_expand_func(user_expand_func, xp, num_file, file)
-user_expand_func_T user_expand_func;
-expand_T           *xp;
-int                *num_file;
-char_u             ***file;
+static void * call_user_expand_func(user_expand_func_T user_expand_func,
+                                    expand_T *xp, int *num_file, char_u ***file)
 {
   int keep = 0;
   char_u num[50];