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, 3 insertions, 6 deletions

diff --git a/src/nvim/os_unix_defs.h b/src/nvim/os_unix_defs.h
index 6a3934b0c8..5ba9d2d98d 100644
--- a/src/nvim/os_unix_defs.h
+++ b/src/nvim/os_unix_defs.h
@@ -41,17 +41,14 @@
 
 #ifdef SIGHASARG
 # ifdef SIGHAS3ARGS
-#  define SIGPROTOARG   (int, int, struct sigcontext *)
-#  define SIGDEFARG(s)  (s, sig2, scont) int s, sig2; struct sigcontext *scont;
+#  define SIGDEFARG(s)  (int s, int sig2, struct sigcontext *scont)
 #  define SIGDUMMYARG   0, 0, (struct sigcontext *)0
 # else
-#  define SIGPROTOARG   (int)
-#  define SIGDEFARG(s)  (s) int s;
+#  define SIGDEFARG(s)  (int s)
 #  define SIGDUMMYARG   0
 # endif
 #else
-# define SIGPROTOARG   (void)
-# define SIGDEFARG(s)  ()
+# define SIGDEFARG(s)  (void)
 # define SIGDUMMYARG
 #endif