Assume C99 or later.

* lib/stdarg.in.h, lib/stdbool.in.h, m4/stdarg.m4, m4/stdbool.m4:
Remove.
* configure.ac (_AC_PROG_CC_C89): Define a dummy, to keep 'configure'
smaller.
(gl_PROG_CC_C99): Use this to get C99 or later.
* lib/gnulib.mk, m4/gnulib-comp.m4: Regenerate.
* admin/merge-gnulib (GNULIB_MODULES): Remove stdarg, stdbool.
(GNULIB_TOOL_FLAGS): Avoid stdarg, stdbool.
* doc/lispref/internals.texi (C Dialect): Document this.
* etc/NEWS: Document this.
* nt/gnulib.mk: Remove stdarg and stdbool modules.
* src/bytecode.c (B__dummy__): Remove.
* src/conf_post.h (bool_bf) [!NS_IMPL_GNUSTEP]: Use bool.
(FLEXIBLE_ARRAY_MEMBER): Now always empty.
* src/dbusbind.c (XD_DEBUG_MESSAGE) [!DBUS_DEBUG]:
* src/regex.c (DEBUG_PRINT): Assume varargs macros.
* src/lisp.h (DEFUN_FUNCTION_INIT): Remove.  All uses now assume C99.

Fixes: debbugs:17487

7 files changed, 23 insertions, 31 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index a89d14bbe23..31fe13e074c 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,13 @@
+2014-05-17  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Assume C99 or later (Bug#17487).
+        * bytecode.c (B__dummy__): Remove.
+        * conf_post.h (bool_bf) [!NS_IMPL_GNUSTEP]: Use bool.
+        (FLEXIBLE_ARRAY_MEMBER): Now always empty.
+        * dbusbind.c (XD_DEBUG_MESSAGE) [!DBUS_DEBUG]:
+        * regex.c (DEBUG_PRINT): Assume varargs macros.
+        * lisp.h (DEFUN_FUNCTION_INIT): Remove.  All uses now assume C99.
+
 2014-05-17  Fabrice Popineau  <fabrice.popineau@gmail.com>
 
         * buffer.c (init_buffer) [USE_MMAP_FOR_BUFFERS]: Always map new
diff --git a/src/bytecode.c b/src/bytecode.c
index f1bdfd9d9c5..f489c74a144 100644
--- a/src/bytecode.c
+++ b/src/bytecode.c
@@ -292,8 +292,6 @@ enum byte_code_op
     Bscan_buffer = 0153, /* No longer generated as of v18.  */
     Bset_mark = 0163, /* this loser is no longer generated as of v18 */
 #endif
-
-    B__dummy__ = 0  /* Pacify C89.  */
 };
 
 /* Whether to maintain a `top' and `bottom' field in the stack frame.  */
diff --git a/src/conf_post.h b/src/conf_post.h
index 95b028a66ee..123f4803da5 100644
--- a/src/conf_post.h
+++ b/src/conf_post.h
@@ -34,9 +34,10 @@ along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
 
 #include <stdbool.h>
 
-/* The pre-C99 <stdbool.h> emulation doesn't work for bool bitfields.
-   Nor does compiling Objective-C with standard GCC.  */
-#if __STDC_VERSION__ < 199901 || NS_IMPL_GNUSTEP
+/* The type of bool bitfields.  Needed to compile Objective-C with
+   standard GCC.  It was also needed to port to pre-C99 compilers,
+   although we don't care about that any more.  */
+#if NS_IMPL_GNUSTEP
 typedef unsigned int bool_bf;
 #else
 typedef bool bool_bf;
@@ -293,14 +294,11 @@ extern void _DebPrint (const char *fmt, ...);
 
 /* To use the struct hack with N elements, declare the struct like this:
      struct s { ...; t name[FLEXIBLE_ARRAY_MEMBER]; };
-   and allocate (offsetof (struct s, name) + N * sizeof (t)) bytes.  */
-#if 199901 <= __STDC_VERSION__
-# define FLEXIBLE_ARRAY_MEMBER
-#elif __GNUC__ && !defined __STRICT_ANSI__
-# define FLEXIBLE_ARRAY_MEMBER 0
-#else
-# define FLEXIBLE_ARRAY_MEMBER 1
-#endif
+   and allocate (offsetof (struct s, name) + N * sizeof (t)) bytes.
+
+   This macro used to expand to something different on pre-C99 compilers.
+   FIXME: Remove it, and remove all uses.  */
+#define FLEXIBLE_ARRAY_MEMBER
 
 /* Use this to suppress gcc's `...may be used before initialized' warnings. */
 #ifdef lint
diff --git a/src/dbusbind.c b/src/dbusbind.c
index 8ebc56c72c4..8997e01b068 100644
--- a/src/dbusbind.c
+++ b/src/dbusbind.c
@@ -142,10 +142,7 @@ static bool xd_in_read_queued_messages = 0;
   } while (0)
 
 #else /* !DBUS_DEBUG */
-# if __STDC_VERSION__ < 199901
-#  define XD_DEBUG_MESSAGE (void) /* Pre-C99 compilers cannot debug.  */
-# else
-#  define XD_DEBUG_MESSAGE(...)                                         \
+# define XD_DEBUG_MESSAGE(...)                                          \
   do {                                                                  \
     if (!NILP (Vdbus_debug))                                            \
       {                                                                 \
@@ -154,7 +151,6 @@ static bool xd_in_read_queued_messages = 0;
         message ("%s: %s", __func__, s);                                \
       }                                                                 \
   } while (0)
-# endif
 # define XD_DEBUG_VALID_LISP_OBJECT_P(object)
 #endif
 
diff --git a/src/emacs.c b/src/emacs.c
index deebb2280c7..16d91de84a4 100644
--- a/src/emacs.c
+++ b/src/emacs.c
@@ -214,7 +214,7 @@ int initial_argc;
 static void sort_args (int argc, char **argv);
 static void syms_of_emacs (void);
 
-/* C89 needs each string be at most 509 characters, so the usage
+/* C99 needs each string to be at most 4095 characters, and the usage
    strings below are split to not overflow this limit.  */
 static char const *const usage_message[] =
   { "\
diff --git a/src/lisp.h b/src/lisp.h
index f47fb0c2a24..67b26ef91c7 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -2654,16 +2654,11 @@ CHECK_NUMBER_CDR (Lisp_Object x)
        minargs, maxargs, lname, intspec, 0};                            \
    Lisp_Object fnname
 #else  /* not _MSC_VER */
-# if __STDC_VERSION__ < 199901
-#  define DEFUN_FUNCTION_INIT(fnname, maxargs) (Lisp_Object (*) (void)) fnname
-# else
-#  define DEFUN_FUNCTION_INIT(fnname, maxargs) .a ## maxargs = fnname
-# endif
 #define DEFUN(lname, fnname, sname, minargs, maxargs, intspec, doc)     \
    Lisp_Object fnname DEFUN_ARGS_ ## maxargs ;                          \
    static struct Lisp_Subr alignas (GCALIGNMENT) sname =                \
      { { PVEC_SUBR << PSEUDOVECTOR_AREA_BITS },                         \
-       { DEFUN_FUNCTION_INIT (fnname, maxargs) },                       \
+       { .a ## maxargs = fnname },                                      \
        minargs, maxargs, lname, intspec, 0};                            \
    Lisp_Object fnname
 #endif
diff --git a/src/regex.c b/src/regex.c
index 622db708b98..ac71b797fbd 100644
--- a/src/regex.c
+++ b/src/regex.c
@@ -1190,12 +1190,7 @@ print_double_string (re_char *where, re_char *string1, ssize_t size1,
 # define assert(e)
 
 # define DEBUG_STATEMENT(e)
-# if __STDC_VERSION__ < 199901L
-#  define DEBUG_COMPILES_ARGUMENTS
-#  define DEBUG_PRINT /* 'DEBUG_PRINT (x, y)' discards X and Y.  */ (void)
-# else
-#  define DEBUG_PRINT(...)
-# endif
+# define DEBUG_PRINT(...)
 # define DEBUG_PRINT_COMPILED_PATTERN(p, s, e)
 # define DEBUG_PRINT_DOUBLE_STRING(w, s1, sz1, s2, sz2)