db: fix build with clang 16

The configure scripts frequently use `main` returning an implicit `int`,
which causes spurious failures when CC is clang 16+. This is fixed by
patching the provided macros and regenerating the scripts with
autoreconfHook, though it requires some manual processing (see below).

The upstream `configure.ac` is written in such a way that it requires
fixups and post-processing.

* Fixups are required because the original build process just cats the
  macros together into one file. When `aclocal` is run, it does not pick
  up all of them. This is worked around by catting the missing macros to
  a file that is picked up by autoreconfHook.
* Post-processing is required to populate the version information. This
  is done in a subshell to avoid polluting the environment with the
  contents of `RELEASE`. Otherwise, the build will fail because the
  version C macros it expects will not be defined.

pkgs/development/libraries/db/clang-4.8.patch

@@ -139,3 +139,67 @@ index f3922e0..e40fcdf 100644
  		} else {
  			DB_ASSERT(env, sharecount > 0);
  			MEMBAR_EXIT();
+diff -ur a/dist/aclocal/clock.m4 b/dist/aclocal/clock.m4
+--- a/dist/aclocal/clock.m4	1969-12-31 19:00:01.000000000 -0500
++++ b/dist/aclocal/clock.m4	2023-06-05 19:14:02.007080500 -0400
+@@ -21,6 +21,7 @@
+ AC_CACHE_CHECK([for clock_gettime monotonic clock], db_cv_clock_monotonic, [
+ AC_TRY_RUN([
+ #include <sys/time.h>
++int
+ main() {
+ 	struct timespec t;
+ 	return (clock_gettime(CLOCK_MONOTONIC, &t) != 0);
+diff -ur a/dist/aclocal/mutex.m4 b/dist/aclocal/mutex.m4
+--- a/dist/aclocal/mutex.m4	1969-12-31 19:00:01.000000000 -0500
++++ b/dist/aclocal/mutex.m4	2023-06-05 19:14:47.214158196 -0400
+@@ -4,6 +4,7 @@
+ AC_DEFUN(AM_PTHREADS_SHARED, [
+ AC_TRY_RUN([
+ #include <pthread.h>
++int
+ main() {
+ 	pthread_cond_t cond;
+ 	pthread_mutex_t mutex;
+@@ -46,6 +47,7 @@
+ AC_DEFUN(AM_PTHREADS_PRIVATE, [
+ AC_TRY_RUN([
+ #include <pthread.h>
++int
+ main() {
+ 	pthread_cond_t cond;
+ 	pthread_mutex_t mutex;
+diff -ur a/dist/aclocal/sequence.m4 b/dist/aclocal/sequence.m4
+--- a/dist/aclocal/sequence.m4	1969-12-31 19:00:01.000000000 -0500
++++ b/dist/aclocal/sequence.m4	2023-06-05 19:14:02.007869956 -0400
+@@ -43,6 +43,9 @@
+ 	# test, which won't test for the appropriate printf format strings.
+ 	if test "$db_cv_build_sequence" = "yes"; then
+ 		AC_TRY_RUN([
++		#include <string.h>
++		#include <stdio.h>
++		int
+ 		main() {
+ 			$db_cv_seq_type l;
+ 			unsigned $db_cv_seq_type u;
+@@ -59,7 +62,9 @@
+				return (1);
+ 			return (0);
+ 		}],, [db_cv_build_sequence="no"],
+-		AC_TRY_LINK(,[
++		AC_TRY_LINK([
++			#include <string.h>
++			#include <stdio.h>],[
+ 			$db_cv_seq_type l;
+ 			unsigned $db_cv_seq_type u;
+ 			char buf@<:@100@:>@;
+diff -ur a/dist/RELEASE b/dist/RELEASE
+--- a/dist/RELEASE	1969-12-31 19:00:01.000000000 -0500
++++ b/dist/RELEASE	2023-07-02 17:32:34.703953049 -0400
+@@ -7,5 +7,5 @@
+ 
+ DB_VERSION_UNIQUE_NAME=`printf "_%d%03d" $DB_VERSION_MAJOR $DB_VERSION_MINOR`
+ 
+-DB_RELEASE_DATE=`date "+%B %e, %Y"`
++DB_RELEASE_DATE="April  9, 2010"
+ DB_VERSION_STRING="Berkeley DB $DB_VERSION: ($DB_RELEASE_DATE)"

pkgs/development/libraries/db/clang-5.3.patch

@@ -139,3 +139,111 @@ index 106b161..fc4de9d 100644
  		} else {
  			DB_ASSERT(env, sharecount > 0);
  			MEMBAR_EXIT();
+diff -ur a/dist/aclocal/clock.m4 b/dist/aclocal/clock.m4
+--- a/dist/aclocal/clock.m4	1969-12-31 19:00:01.000000000 -0500
++++ b/dist/aclocal/clock.m4	2023-06-05 19:14:02.007080500 -0400
+@@ -21,6 +21,7 @@
+ AC_CACHE_CHECK([for clock_gettime monotonic clock], db_cv_clock_monotonic, [
+ AC_TRY_RUN([
+ #include <sys/time.h>
++int
+ main() {
+ 	struct timespec t;
+ 	return (clock_gettime(CLOCK_MONOTONIC, &t) != 0);
+diff -ur a/dist/aclocal/mmap.m4 b/dist/aclocal/mmap.m4
+--- a/dist/aclocal/mmap.m4	1969-12-31 19:00:01.000000000 -0500
++++ b/dist/aclocal/mmap.m4	2023-06-05 19:14:02.007323624 -0400
+@@ -29,6 +29,8 @@
+      * system to system.
+      */
+     #include <stdio.h>
++    #include <stdlib.h>
++    #include <unistd.h>
+     #include <string.h>
+     #include <sys/types.h>
+     #include <sys/stat.h>
+@@ -42,12 +44,13 @@
+     #define MAP_FAILED (-1)
+     #endif
+
+-    int catch_sig(sig)
++    void catch_sig(sig)
+ 	    int sig;
+     {
+ 	    exit(1);
+     }
+
++    int
+     main() {
+ 	    const char *underlying;
+ 	    unsigned gapsize;
+@@ -88,8 +91,8 @@
+ 		    return (4);
+ 	    }
+
+-	    (void) signal(SIGSEGV, catch_sig);
+-	    (void) signal(SIGBUS, catch_sig);
++	    (void) signal(SIGSEGV, &catch_sig);
++	    (void) signal(SIGBUS, &catch_sig);
+
+ 	    for (i = sizeof(buf); i < total_size; i += gapsize)
+ 		    base[i] = 'A';
+diff -ur a/dist/aclocal/mutex.m4 b/dist/aclocal/mutex.m4
+--- a/dist/aclocal/mutex.m4	1969-12-31 19:00:01.000000000 -0500
++++ b/dist/aclocal/mutex.m4	2023-06-05 19:14:47.214158196 -0400
+@@ -5,6 +5,7 @@
+ AC_TRY_RUN([
+ #include <stdlib.h>
+ #include <pthread.h>
++int
+ main() {
+ 	pthread_cond_t cond;
+ 	pthread_mutex_t mutex;
+@@ -49,6 +50,7 @@
+ AC_TRY_RUN([
+ #include <stdlib.h>
+ #include <pthread.h>
++int
+ main() {
+ 	pthread_cond_t cond;
+ 	pthread_mutex_t mutex;
+@@ -89,6 +91,7 @@
+ AC_TRY_RUN([
+ #include <stdlib.h>
+ #include <pthread.h>
++int
+ main() {
+ 	pthread_cond_t cond;
+ 	pthread_condattr_t condattr;
+@@ -110,6 +113,7 @@
+ AC_TRY_RUN([
+ #include <stdlib.h>
+ #include <pthread.h>
++int
+ main() {
+ 	pthread_rwlock_t rwlock;
+ 	pthread_rwlockattr_t rwlockattr;
+diff -ur a/dist/aclocal/sequence.m4 b/dist/aclocal/sequence.m4
+--- a/dist/aclocal/sequence.m4	1969-12-31 19:00:01.000000000 -0500
++++ b/dist/aclocal/sequence.m4	2023-06-05 19:14:02.007869956 -0400
+@@ -43,6 +43,9 @@
+ 	# test, which won't test for the appropriate printf format strings.
+ 	if test "$db_cv_build_sequence" = "yes"; then
+ 		AC_TRY_RUN([
++		#include <string.h>
++		#include <stdio.h>
++		int
+ 		main() {
+ 			$db_cv_seq_type l;
+ 			unsigned $db_cv_seq_type u;
+@@ -59,7 +62,9 @@
+				return (1);
+ 			return (0);
+ 		}],, [db_cv_build_sequence="no"],
+-		AC_TRY_LINK(,[
++		AC_TRY_LINK([
++			#include <string.h>
++			#include <stdio.h>],[
+ 			$db_cv_seq_type l;
+ 			unsigned $db_cv_seq_type u;
+ 			char buf@<:@100@:>@;

pkgs/development/libraries/db/db-4.8.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, ... } @ args:
+{ lib, stdenv, fetchurl, autoreconfHook, ... } @ args:
 
 import ./generic.nix (args // {
   version = "4.8.30";

pkgs/development/libraries/db/db-5.3.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, ... } @ args:
+{ lib, stdenv, fetchurl, autoreconfHook, ... } @ args:
 
 import ./generic.nix (args // {
   version = "5.3.28";

pkgs/development/libraries/db/db-6.0.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, ... } @ args:
+{ lib, stdenv, fetchurl, autoreconfHook, ... } @ args:
 
 import ./generic.nix (args // {
   version = "6.0.20";

pkgs/development/libraries/db/db-6.2.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl, ... } @ args:
+{ lib, stdenv, fetchurl, autoreconfHook, ... } @ args:
 
 import ./generic.nix (args // {
   version = "6.2.23";

pkgs/development/libraries/db/generic.nix

@@ -1,4 +1,4 @@
-{ lib, stdenv, fetchurl
+{ lib, stdenv, fetchurl, autoreconfHook
 , cxxSupport ? true
 , compat185 ? true
 , dbmSupport ? false
@@ -10,6 +10,9 @@
 , drvArgs ? {}
 }:
 
+let
+  shouldReconfigure = stdenv.cc.isClang;
+in
 stdenv.mkDerivation (rec {
   pname = "db";
   inherit version;
@@ -19,10 +22,48 @@ stdenv.mkDerivation (rec {
     sha256 = sha256;
   };
 
+  # The provided configure script features `main` returning implicit `int`, which causes
+  # configure checks to work incorrectly with clang 16.
+  nativeBuildInputs = lib.optionals stdenv.cc.isClang [ autoreconfHook ];
+
   patches = extraPatches;
 
   outputs = [ "bin" "out" "dev" ];
 
+  # Required when regenerated the configure script to make sure the vendored macros are found.
+  autoreconfFlags = lib.optionalString shouldReconfigure [ "-fi" "-Iaclocal" "-Iaclocal_java" ];
+
+  preAutoreconf = lib.optionalString shouldReconfigure ''
+    pushd dist
+    # Upstream’s `dist/s_config` cats everything into `aclocal.m4`, but that doesn’t work with
+    # autoreconfHook, so cat `config.m4` to another file. Otherwise, it won’t be found by `aclocal`.
+    cat aclocal/config.m4 >> aclocal/options.m4
+  '';
+
+  # This isn’t pretty. The version information is kept separate from the configure script.
+  # After the configure script is regenerated, the version information has to be replaced with the
+  # contents of `dist/RELEASE`.
+  postAutoreconf = lib.optionalString shouldReconfigure ''
+    (
+      declare -a vars=(
+        "DB_VERSION_FAMILY"
+        "DB_VERSION_RELEASE"
+        "DB_VERSION_MAJOR"
+        "DB_VERSION_MINOR"
+        "DB_VERSION_PATCH"
+        "DB_VERSION_STRING"
+        "DB_VERSION_FULL_STRING"
+        "DB_VERSION_UNIQUE_NAME"
+        "DB_VERSION"
+      )
+      source RELEASE
+      for var in "''${vars[@]}"; do
+        sed -e "s/__EDIT_''${var}__/''${!var}/g" -i configure
+      done
+    )
+    popd
+  '';
+
   configureFlags =
     [
       (if cxxSupport then "--enable-cxx" else "--disable-cxx")