sys-devel/autoconf: backport K&R decls fix to 2.13

Backport the K&R decls fix to 2.13 to avoid configure tests
failing (often "silently", i.e. doesn't fail the build of
the package overall, just leads to wrong results) with
newer compilers like the upcoming Clang 16.

A consequence of this whole fuss is that we're going to
have to eautoreconf in a bunch of older packages, but
as Ionen pointed out on IRC, this means we get some
other stuff for free like Python 3.10 fixes, so it's
not all bad.

Undecided how to handle any packages with a generated
configure from autoconfs not in tree. We may just
patch the configure manually. Will see.

See linked bug 870412 and the Discourse thread therein for
details if unfamiliar.

As I remarked on IRC, it's unfortunate to have to backport anything
which will then infect generated configure, as it's somewhat
a repeat of the --runstatedir situation, and it leads to confusion/hassle
when sending patches upstream where a generated/bootstrapped configure
is required.

But this is different - it's a (serious) bug being fixed
rather than a gratuitous (although) understandable given we weren't
sure if we'd ever see another autoconf release backport of a new
feature.

Bug: https://bugs.gentoo.org/806376
Bug: https://bugs.gentoo.org/870412
Thanks-to: Arsen Arsenovic <arsen@aarsen.me>
Signed-off-by: Sam James <sam@gentoo.org>

2 files changed, 397 insertions, 0 deletions

diff --git a/sys-devel/autoconf/autoconf-2.13-r3.ebuild b/sys-devel/autoconf/autoconf-2.13-r3.ebuild
new file mode 100644
index 000000000000..89c4e8c53c6d
--- /dev/null
+++ b/sys-devel/autoconf/autoconf-2.13-r3.ebuild
@@ -0,0 +1,51 @@
+# Copyright 1999-2022 Gentoo Authors
+# Distributed under the terms of the GNU General Public License v2
+
+EAPI=7
+
+inherit toolchain-autoconf
+
+DESCRIPTION="Used to create autoconfiguration files"
+HOMEPAGE="https://www.gnu.org/software/autoconf/autoconf.html"
+SRC_URI="mirror://gnu/${PN}/${P}.tar.gz"
+
+LICENSE="GPL-2"
+SLOT="${PV:0:3}"
+KEYWORDS="~alpha ~amd64 ~arm ~arm64 ~hppa ~ia64 ~loong ~m68k ~mips ~ppc ~ppc64 ~riscv ~s390 ~sparc ~x86 ~amd64-linux ~x86-linux ~ppc-macos ~x64-macos ~sparc-solaris ~x64-solaris ~x86-solaris"
+
+BDEPEND="
+	sys-devel/m4
+	dev-lang/perl"
+RDEPEND="${BDEPEND}
+	sys-apps/texinfo
+	>=sys-devel/autoconf-wrapper-13"
+
+PATCHES=(
+	"${FILESDIR}"/${P}-gentoo.patch
+	"${FILESDIR}"/${P}-destdir.patch
+	"${FILESDIR}"/${P}-test-fixes.patch #146592
+	"${FILESDIR}"/${P}-perl-5.26.patch
+	"${FILESDIR}"/${P}-K-R-decls-clang.patch
+)
+
+src_configure() {
+	# make sure configure is newer than configure.in
+	touch configure || die
+
+	# need to include --exec-prefix and --bindir or our
+	# DESTDIR patch will trigger sandbox hate :(
+	#
+	# need to force locale to C to avoid bugs in the old
+	# configure script breaking the install paths #351982
+	#
+	# force to `awk` so that we don't encode another awk that
+	# happens to currently be installed, but might later be
+	# uninstalled (like mawk).  same for m4.
+	ac_cv_path_M4="m4" \
+	ac_cv_prog_AWK="awk" \
+	LC_ALL=C \
+	econf \
+		--exec-prefix="${EPREFIX}"/usr \
+		--bindir="${EPREFIX}"/usr/bin \
+		--program-suffix="-${PV}"
+}
diff --git a/sys-devel/autoconf/files/autoconf-2.13-K-R-decls-clang.patch b/sys-devel/autoconf/files/autoconf-2.13-K-R-decls-clang.patch
new file mode 100644
index 000000000000..874712cea102
--- /dev/null
+++ b/sys-devel/autoconf/files/autoconf-2.13-K-R-decls-clang.patch
@@ -0,0 +1,346 @@
+https://bugs.gentoo.org/870412
+https://git.savannah.gnu.org/cgit/autoconf.git/commit/?id=8b5e2016c7ed2d67f31b03a3d2e361858ff5299b
+
+Backport the K&R decls fix to 2.69 to avoid configure tests
+failing (often "silently", i.e. doesn't fail the build of
+the package overall, just leads to wrong results) with
+newer compilers like the upcoming Clang 16.
+
+From d8ad1096be4352c588b9bc1e16b6758f4f32b96a Mon Sep 17 00:00:00 2001
+From: =?UTF-8?q?Arsen=20Arsenovi=C4=87?= <arsen@aarsen.me>
+Date: Mon, 19 Sep 2022 01:38:29 +0200
+Subject: [PATCH] ac{general,specific}: declare void param lists, where apt
+
+--- a/acgeneral.m4
++++ b/acgeneral.m4
+@@ -1542,7 +1542,7 @@ extern "C"
+ ])dnl
+ [/* We use char because int might match the return type of a gcc2
+     builtin and then its argument prototype would still apply.  */
+-char $1();
++char $1(void);
+ ]),
+ [$1()],
+ [$2],
+@@ -1597,7 +1597,7 @@ extern "C"
+ ])dnl
+ [/* We use char because int might match the return type of a gcc2
+     builtin and then its argument prototype would still apply.  */
+-char $2();
++char $2(void);
+ ])),
+ 	    [$2()],
+ 	    eval "ac_cv_lib_$ac_lib_var=yes",
+@@ -1733,7 +1733,7 @@ dnl [#]line __oline__ "[$]0"
+ [#]line __oline__ "configure"
+ #include "confdefs.h"
+ [$1]
+-int main() {
++int main(void) {
+ [$2]
+ ; return 0; }
+ ])EOF
+@@ -1777,7 +1777,7 @@ dnl [#]line __oline__ "[$]0"
+ [#]line __oline__ "configure"
+ #include "confdefs.h"
+ [$1]
+-int main() {
++int main(void) {
+ [$2]
+ ; return 0; }
+ ])EOF
+@@ -1934,7 +1934,7 @@ extern "C"
+ ])dnl
+ [/* We use char because int might match the return type of a gcc2
+     builtin and then its argument prototype would still apply.  */
+-char $1();
++char $1(void);
+ ], [
+ /* The GNU C library defines this for functions which it implements
+     to always fail with ENOSYS.  Some functions are actually named
+@@ -1988,7 +1988,7 @@ changequote([, ])dnl
+ AC_MSG_CHECKING(size of $1)
+ AC_CACHE_VAL(AC_CV_NAME,
+ [AC_TRY_RUN([#include <stdio.h>
+-main()
++main(void)
+ {
+   FILE *f=fopen("conftestval", "w");
+   if (!f) exit(1);
+--- a/acspecific.m4
++++ b/acspecific.m4
+@@ -202,7 +202,7 @@ AC_DEFUN(AC_PROG_CC_WORKS,
+ [AC_MSG_CHECKING([whether the C compiler ($CC $CFLAGS $LDFLAGS) works])
+ AC_LANG_SAVE
+ AC_LANG_C
+-AC_TRY_COMPILER([main(){return(0);}], ac_cv_prog_cc_works, ac_cv_prog_cc_cross)
++AC_TRY_COMPILER([int main(void){return(0);}], ac_cv_prog_cc_works, ac_cv_prog_cc_cross)
+ AC_LANG_RESTORE
+ AC_MSG_RESULT($ac_cv_prog_cc_works)
+ if test $ac_cv_prog_cc_works = no; then
+@@ -217,7 +217,7 @@ AC_DEFUN(AC_PROG_CXX_WORKS,
+ [AC_MSG_CHECKING([whether the C++ compiler ($CXX $CXXFLAGS $LDFLAGS) works])
+ AC_LANG_SAVE
+ AC_LANG_CPLUSPLUS
+-AC_TRY_COMPILER([int main(){return(0);}], ac_cv_prog_cxx_works, ac_cv_prog_cxx_cross)
++AC_TRY_COMPILER([int main(void){return(0);}], ac_cv_prog_cxx_works, ac_cv_prog_cxx_cross)
+ AC_LANG_RESTORE
+ AC_MSG_RESULT($ac_cv_prog_cxx_works)
+ if test $ac_cv_prog_cxx_works = no; then
+@@ -300,7 +300,7 @@ fi])])
+ 
+ AC_DEFUN(AC_PROG_CC_G,
+ [AC_CACHE_CHECK(whether ${CC-cc} accepts -g, ac_cv_prog_cc_g,
+-[echo 'void f(){}' > conftest.c
++[echo 'void f(void){}' > conftest.c
+ if test -z "`${CC-cc} -g -c conftest.c 2>&1`"; then
+   ac_cv_prog_cc_g=yes
+ else
+@@ -311,7 +311,7 @@ rm -f conftest*
+ 
+ AC_DEFUN(AC_PROG_CXX_G,
+ [AC_CACHE_CHECK(whether ${CXX-g++} accepts -g, ac_cv_prog_cxx_g,
+-[echo 'void f(){}' > conftest.cc
++[echo 'void f(void){}' > conftest.cc
+ if test -z "`${CXX-g++} -g -c conftest.cc 2>&1`"; then
+   ac_cv_prog_cxx_g=yes
+ else
+@@ -371,7 +371,7 @@ changequote(, )dnl
+ 		       sed -e 's/[^a-zA-Z0-9_]/_/g' -e 's/^[0-9]/_/'`"
+ changequote([, ])dnl
+ AC_CACHE_VAL(ac_cv_prog_cc_${ac_cc}_c_o,
+-[echo 'foo(){}' > conftest.c
++[echo 'foo(void){}' > conftest.c
+ # Make sure it works both with $CC and with simple cc.
+ # We do the test twice because some compilers refuse to overwrite an
+ # existing .o file with -o, though they will create one.
+@@ -709,7 +709,7 @@ AC_TRY_RUN([#include <ctype.h>
+ #define ISLOWER(c) ('a' <= (c) && (c) <= 'z')
+ #define TOUPPER(c) (ISLOWER(c) ? 'A' + ((c) - 'a') : (c))
+ #define XOR(e, f) (((e) && !(f)) || (!(e) && (f)))
+-int main () { int i; for (i = 0; i < 256; i++)
++int main (void) { int i; for (i = 0; i < 256; i++)
+ if (XOR (islower (i), ISLOWER (i)) || toupper (i) != TOUPPER (i)) exit(2);
+ exit (0); }
+ ], , ac_cv_header_stdc=no, :)
+@@ -820,7 +820,7 @@ esac
+ AC_CACHE_CHECK(whether closedir returns void, ac_cv_func_closedir_void,
+ [AC_TRY_RUN([#include <sys/types.h>
+ #include <$ac_header_dirent>
+-int closedir(); main() { exit(closedir(opendir(".")) != 0); }],
++int closedir(...); int main(void) { exit(closedir(opendir(".")) != 0); }],
+   ac_cv_func_closedir_void=no, ac_cv_func_closedir_void=yes, ac_cv_func_closedir_void=yes)])
+ if test $ac_cv_func_closedir_void = yes; then
+   AC_DEFINE(VOID_CLOSEDIR)
+@@ -911,7 +911,7 @@ changequote(<<, >>)dnl
+ #define NGID 256
+ #undef MAX
+ #define MAX(x, y) ((x) > (y) ? (x) : (y))
+-main()
++int main(void)
+ {
+   gid_t gidset[NGID];
+   int i, n;
+@@ -973,7 +973,7 @@ AC_DEFUN(AC_TYPE_SIGNAL,
+ #ifdef __cplusplus
+ extern "C" void (*signal (int, void (*)(int)))(int);
+ #else
+-void (*signal ()) ();
++void (*signal (void)) (void);
+ #endif
+ ],
+ [int i;], ac_cv_type_signal=void, ac_cv_type_signal=int)])
+@@ -989,7 +989,7 @@ AC_DEFUN(AC_FUNC_CLOSEDIR_VOID,
+ AC_CACHE_CHECK(whether closedir returns void, ac_cv_func_closedir_void,
+ [AC_TRY_RUN([#include <sys/types.h>
+ #include <$ac_header_dirent>
+-int closedir(); main() { exit(closedir(opendir(".")) != 0); }],
++int closedir(...); int main(void) { exit(closedir(opendir(".")) != 0); }],
+   ac_cv_func_closedir_void=no, ac_cv_func_closedir_void=yes, ac_cv_func_closedir_void=yes)])
+ if test $ac_cv_func_closedir_void = yes; then
+   AC_DEFINE(CLOSEDIR_VOID)
+@@ -1001,7 +1001,7 @@ AC_DEFUN(AC_FUNC_FNMATCH,
+ # Some versions of Solaris or SCO have a broken fnmatch function.
+ # So we run a test program.  If we are cross-compiling, take no chance.
+ # Thanks to John Oleynick and Franc,ois Pinard for this test.
+-[AC_TRY_RUN([main() { exit (fnmatch ("a*", "abc", 0) != 0); }],
++[AC_TRY_RUN([int main(void) { exit (fnmatch ("a*", "abc", 0) != 0); }],
+ ac_cv_func_fnmatch_works=yes, ac_cv_func_fnmatch_works=no,
+ ac_cv_func_fnmatch_works=no)])
+ if test $ac_cv_func_fnmatch_works = yes; then
+@@ -1083,11 +1083,11 @@ AC_CACHE_CHECK(for working mmap, ac_cv_func_mmap_fixed_mapped,
+ #ifdef __cplusplus
+ extern "C" { void *malloc(unsigned); }
+ #else
+-char *malloc();
++char *malloc(...);
+ #endif
+ 
+ int
+-main()
++main(void)
+ {
+ 	char *data, *data2, *data3;
+ 	int i, pagesize;
+@@ -1172,7 +1172,7 @@ int     pid;
+ int     pg1, pg2, pg3, pg4;
+ int     ng, np, s, child;
+ 
+-main()
++int main(void)
+ {
+         pid = getpid();
+         pg1 = getpgrp(0);
+@@ -1228,7 +1228,7 @@ AC_TRY_RUN([
+  * If this system has a BSD-style setpgrp, which takes arguments, exit
+  * successfully.
+  */
+-main()
++int main(void)
+ {
+     if (setpgrp(1,1) == -1)
+ 	exit(0);
+@@ -1291,7 +1291,7 @@ sparc_address_test (arg) int arg;
+     }
+   }
+ }
+-main() {
++int main(void) {
+   pid_t parent = getpid ();
+   pid_t child;
+ 
+@@ -1360,7 +1360,7 @@ AC_DEFUN(AC_FUNC_WAIT3,
+ #include <sys/resource.h>
+ #include <stdio.h>
+ /* HP-UX has wait3 but does not fill in rusage at all.  */
+-main() {
++int main(void) {
+   struct rusage r;
+   int i;
+   /* Use a field that we can force nonzero --
+@@ -1416,7 +1416,7 @@ AC_CACHE_CHECK([for alloca], ac_cv_func_alloca_works,
+  #pragma alloca
+ #   else
+ #    ifndef alloca /* predefined by HP cc +Olibcalls */
+-char *alloca ();
++char *alloca (...);
+ #    endif
+ #   endif
+ #  endif
+@@ -1464,7 +1464,7 @@ AC_CACHE_CHECK(stack direction for C alloca, ac_cv_c_stack_direction,
+   else
+     return (&dummy > addr) ? 1 : -1;
+ }
+-main ()
++int main (void)
+ {
+   exit (find_stack_direction() < 0);
+ }], ac_cv_c_stack_direction=1, ac_cv_c_stack_direction=-1,
+@@ -1582,7 +1582,7 @@ AC_DEFUN(AC_FUNC_UTIME_NULL,
+ # Sequent interprets utime(file, 0) to mean use start of epoch.  Wrong.
+ AC_TRY_RUN([#include <sys/types.h>
+ #include <sys/stat.h>
+-main() {
++int main(void) {
+ struct stat s, t;
+ exit(!(stat ("conftestdata", &s) == 0 && utime("conftestdata", (long *)0) == 0
+ && stat("conftestdata", &t) == 0 && t.st_mtime >= s.st_mtime
+@@ -1598,7 +1598,7 @@ fi
+ AC_DEFUN(AC_FUNC_STRCOLL,
+ [AC_CACHE_CHECK(for working strcoll, ac_cv_func_strcoll_works,
+ [AC_TRY_RUN([#include <string.h>
+-main ()
++int main (void)
+ {
+   exit (strcoll ("abc", "def") >= 0 ||
+ 	strcoll ("ABC", "DEF") >= 0 ||
+@@ -1615,7 +1615,7 @@ AC_DEFUN(AC_FUNC_SETVBUF_REVERSED,
+   ac_cv_func_setvbuf_reversed,
+ [AC_TRY_RUN([#include <stdio.h>
+ /* If setvbuf has the reversed format, exit 0. */
+-main () {
++int main (void) {
+   /* This call has the arguments reversed.
+      A reversed system may check and see that the address of main
+      is not _IOLBF, _IONBF, or _IOFBF, and return nonzero.  */
+@@ -1647,7 +1647,7 @@ LIBS="-lintl $LIBS"])])])
+ AC_DEFUN(AC_FUNC_MEMCMP,
+ [AC_CACHE_CHECK(for 8-bit clean memcmp, ac_cv_func_memcmp_clean,
+ [AC_TRY_RUN([
+-main()
++int main(void)
+ {
+   char c0 = 0x40, c1 = 0x80, c2 = 0x81;
+   exit(memcmp(&c0, &c2, 1) < 0 && memcmp(&c1, &c2, 1) < 0 ? 0 : 1);
+@@ -1805,7 +1805,7 @@ AC_TRY_RUN(
+ #if !defined(__STDC__) || __STDC__ != 1
+ #define volatile
+ #endif
+-main() {
++int main(void) {
+   volatile char c = 255; exit(c < 0);
+ }], ac_cv_c_char_unsigned=yes, ac_cv_c_char_unsigned=no)
+ fi])
+@@ -1819,7 +1819,7 @@ AC_DEFUN(AC_C_LONG_DOUBLE,
+ [if test "$GCC" = yes; then
+   ac_cv_c_long_double=yes
+ else
+-AC_TRY_RUN([int main() {
++AC_TRY_RUN([int main(void) {
+ /* The Stardent Vistra knows sizeof(long double), but does not support it.  */
+ long double foo = 0.0;
+ /* On Ultrix 4.3 cc, long double is 4 and double is 8.  */
+@@ -1834,7 +1834,7 @@ fi
+ AC_DEFUN(AC_INT_16_BITS,
+ [AC_OBSOLETE([$0], [; instead use AC_CHECK_SIZEOF(int)])dnl
+ AC_MSG_CHECKING(whether int is 16 bits)
+-AC_TRY_RUN([main() { exit(sizeof(int) != 2); }],
++AC_TRY_RUN([int main(void) { exit(sizeof(int) != 2); }],
+  [AC_MSG_RESULT(yes)
+  AC_DEFINE(INT_16_BITS)], AC_MSG_RESULT(no))
+ ])
+@@ -1842,7 +1842,7 @@ AC_TRY_RUN([main() { exit(sizeof(int) != 2); }],
+ AC_DEFUN(AC_LONG_64_BITS,
+ [AC_OBSOLETE([$0], [; instead use AC_CHECK_SIZEOF(long)])dnl
+ AC_MSG_CHECKING(whether long int is 64 bits)
+-AC_TRY_RUN([main() { exit(sizeof(long int) != 8); }],
++AC_TRY_RUN([int main(void) { exit(sizeof(long int) != 8); }],
+  [AC_MSG_RESULT(yes)
+  AC_DEFINE(LONG_64_BITS)], AC_MSG_RESULT(no))
+ ])
+@@ -1862,7 +1862,7 @@ AC_TRY_COMPILE([#include <sys/types.h>
+  not big endian
+ #endif], ac_cv_c_bigendian=yes, ac_cv_c_bigendian=no)])
+ if test $ac_cv_c_bigendian = unknown; then
+-AC_TRY_RUN([main () {
++AC_TRY_RUN([int main (void) {
+   /* Are we little or big endian?  From Harbison&Steele.  */
+   union
+   {
+@@ -1885,7 +1885,7 @@ AC_DEFUN(AC_C_INLINE,
+ [AC_CACHE_CHECK([for inline], ac_cv_c_inline,
+ [ac_cv_c_inline=no
+ for ac_kw in inline __inline__ __inline; do
+-  AC_TRY_COMPILE(, [} $ac_kw foo() {], [ac_cv_c_inline=$ac_kw; break])
++  AC_TRY_COMPILE(, [} $ac_kw foo(void) {], [ac_cv_c_inline=$ac_kw; break])
+ done
+ ])
+ case "$ac_cv_c_inline" in
+@@ -2277,7 +2277,7 @@ AC_DEFUN(AC_SYS_RESTARTABLE_SYSCALLS,
+ #include <sys/types.h>
+ #include <signal.h>
+ ucatch (isig) { }
+-main () {
++int main (void) {
+   int i = fork (), status;
+   if (i == 0) { sleep (3); kill (getppid (), SIGINT); sleep (3); exit (0); }
+   signal (SIGINT, ucatch);
+@@ -2654,7 +2654,7 @@ AC_CACHE_VAL(ac_cv_exeext,
+   ac_cv_exeext=.exe
+ else
+   rm -f conftest*
+-  echo 'int main () { return 0; }' > conftest.$ac_ext
++  echo 'int main (void) { return 0; }' > conftest.$ac_ext
+   ac_cv_exeext=
+   if AC_TRY_EVAL(ac_link); then
+     for file in conftest.*; do