gh-94801: Use custom flags to check for headers and libs (#94802)

3 files changed, 407 insertions, 318 deletions

diff --git a/Misc/NEWS.d/next/Build/2022-07-13-10-13-10.gh-issue-94801.3xUB24.rst b/Misc/NEWS.d/next/Build/2022-07-13-10-13-10.gh-issue-94801.3xUB24.rst
new file mode 100644
index 0000000..5caf84f
--- /dev/null
+++ b/Misc/NEWS.d/next/Build/2022-07-13-10-13-10.gh-issue-94801.3xUB24.rst
@@ -0,0 +1,2 @@
+``configure`` now uses custom flags like ``ZLIB_CFLAGS`` and ``ZLIB_LIBS``
+when searching for headers and libraries.
diff --git a/configure b/configure
index 55d0518..df6b193 100755
--- a/configure
+++ b/configure
@@ -3090,6 +3090,10 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
 
 
 
+
+
+
+
 if test "$srcdir" != . -a "$srcdir" != "$(pwd)"; then
     # If we're building out-of-tree, we need to make sure the following
     # resources get picked up before their $srcdir counterparts.
@@ -11263,7 +11267,15 @@ fi
 	echo "$LIBUUID_PKG_ERRORS" >&5
 
 
-      for ac_header in uuid/uuid.h
+      save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+        CPPFLAGS="$CFLAGS $LIBUUID_CFLAGS"
+        LDFLAGS="$LDFLAGS $LIBUUID_LIBS"
+        for ac_header in uuid/uuid.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "uuid/uuid.h" "ac_cv_header_uuid_uuid_h" "$ac_includes_default"
 if test "x$ac_cv_header_uuid_uuid_h" = xyes; then :
@@ -11271,11 +11283,7 @@ if test "x$ac_cv_header_uuid_uuid_h" = xyes; then :
 #define HAVE_UUID_UUID_H 1
 _ACEOF
 
-        save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
+          py_check_lib_save_LIBS=$LIBS
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for uuid_generate_time in -luuid" >&5
 $as_echo_n "checking for uuid_generate_time in -luuid... " >&6; }
 if ${ac_cv_lib_uuid_uuid_generate_time+:} false; then :
@@ -11316,20 +11324,10 @@ if test "x$ac_cv_lib_uuid_uuid_generate_time" = xyes; then :
   have_uuid=yes
 fi
 
+LIBS=$py_check_lib_save_LIBS
 
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
-        save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking for uuid_generate_time_safe in -luuid" >&5
+          py_check_lib_save_LIBS=$LIBS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for uuid_generate_time_safe in -luuid" >&5
 $as_echo_n "checking for uuid_generate_time_safe in -luuid... " >&6; }
 if ${ac_cv_lib_uuid_uuid_generate_time_safe+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -11366,19 +11364,18 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_uuid_uuid_generate_time_safe" >&5
 $as_echo "$ac_cv_lib_uuid_uuid_generate_time_safe" >&6; }
 if test "x$ac_cv_lib_uuid_uuid_generate_time_safe" = xyes; then :
-
-            have_uuid=yes
+  have_uuid=yes
             $as_echo "#define HAVE_UUID_GENERATE_TIME_SAFE 1" >>confdefs.h
 
 
 fi
 
+LIBS=$py_check_lib_save_LIBS
 
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
 
+fi
+
+done
 
         if test "x$have_uuid" = xyes; then :
 
@@ -11387,9 +11384,11 @@ LIBS=$save_LIBS
 
 fi
 
-fi
+CFLAGS=$save_CFLAGS
+CPPFLAGS=$save_CPPFLAGS
+LDFLAGS=$save_LDFLAGS
+LIBS=$save_LIBS
 
-done
 
 
 
@@ -11397,7 +11396,15 @@ elif test $pkg_failed = untried; then
      	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 
-      for ac_header in uuid/uuid.h
+      save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+        CPPFLAGS="$CFLAGS $LIBUUID_CFLAGS"
+        LDFLAGS="$LDFLAGS $LIBUUID_LIBS"
+        for ac_header in uuid/uuid.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "uuid/uuid.h" "ac_cv_header_uuid_uuid_h" "$ac_includes_default"
 if test "x$ac_cv_header_uuid_uuid_h" = xyes; then :
@@ -11405,11 +11412,7 @@ if test "x$ac_cv_header_uuid_uuid_h" = xyes; then :
 #define HAVE_UUID_UUID_H 1
 _ACEOF
 
-        save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
+          py_check_lib_save_LIBS=$LIBS
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for uuid_generate_time in -luuid" >&5
 $as_echo_n "checking for uuid_generate_time in -luuid... " >&6; }
 if ${ac_cv_lib_uuid_uuid_generate_time+:} false; then :
@@ -11450,20 +11453,10 @@ if test "x$ac_cv_lib_uuid_uuid_generate_time" = xyes; then :
   have_uuid=yes
 fi
 
+LIBS=$py_check_lib_save_LIBS
 
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
-
-
-        save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-          { $as_echo "$as_me:${as_lineno-$LINENO}: checking for uuid_generate_time_safe in -luuid" >&5
+          py_check_lib_save_LIBS=$LIBS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for uuid_generate_time_safe in -luuid" >&5
 $as_echo_n "checking for uuid_generate_time_safe in -luuid... " >&6; }
 if ${ac_cv_lib_uuid_uuid_generate_time_safe+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -11500,19 +11493,18 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_uuid_uuid_generate_time_safe" >&5
 $as_echo "$ac_cv_lib_uuid_uuid_generate_time_safe" >&6; }
 if test "x$ac_cv_lib_uuid_uuid_generate_time_safe" = xyes; then :
-
-            have_uuid=yes
+  have_uuid=yes
             $as_echo "#define HAVE_UUID_GENERATE_TIME_SAFE 1" >>confdefs.h
 
 
 fi
 
+LIBS=$py_check_lib_save_LIBS
 
-CFLAGS=$save_CFLAGS
-CPPFLAGS=$save_CPPFLAGS
-LDFLAGS=$save_LDFLAGS
-LIBS=$save_LIBS
 
+fi
+
+done
 
         if test "x$have_uuid" = xyes; then :
 
@@ -11521,9 +11513,11 @@ LIBS=$save_LIBS
 
 fi
 
-fi
+CFLAGS=$save_CFLAGS
+CPPFLAGS=$save_CPPFLAGS
+LDFLAGS=$save_LDFLAGS
+LIBS=$save_LIBS
 
-done
 
 
 
@@ -12122,15 +12116,17 @@ fi
 	echo "$LIBFFI_PKG_ERRORS" >&5
 
 
-    ac_fn_c_check_header_mongrel "$LINENO" "ffi.h" "ac_cv_header_ffi_h" "$ac_includes_default"
-if test "x$ac_cv_header_ffi_h" = xyes; then :
-
-      save_CFLAGS=$CFLAGS
+    save_CFLAGS=$CFLAGS
 save_CPPFLAGS=$CPPFLAGS
 save_LDFLAGS=$LDFLAGS
 save_LIBS=$LIBS
 
 
+      CPPFLAGS="$CFLAGS $LIBFFI_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBFFI_LIBS"
+      ac_fn_c_check_header_mongrel "$LINENO" "ffi.h" "ac_cv_header_ffi_h" "$ac_includes_default"
+if test "x$ac_cv_header_ffi_h" = xyes; then :
+
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ffi_call in -lffi" >&5
 $as_echo_n "checking for ffi_call in -lffi... " >&6; }
 if ${ac_cv_lib_ffi_ffi_call+:} false; then :
@@ -12170,13 +12166,18 @@ $as_echo "$ac_cv_lib_ffi_ffi_call" >&6; }
 if test "x$ac_cv_lib_ffi_ffi_call" = xyes; then :
 
           have_libffi=yes
-          LIBFFI_LIBS="-lffi"
+          LIBFFI_CFLAGS=${LIBFFI_CFLAGS-""}
+          LIBFFI_LIBS=${LIBFFI_LIBS-"-lffi"}
 
 else
   have_libffi=no
 fi
 
 
+fi
+
+
+
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
 LDFLAGS=$save_LDFLAGS
@@ -12184,23 +12185,21 @@ LIBS=$save_LIBS
 
 
 
-fi
-
-
-
 elif test $pkg_failed = untried; then
      	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 
-    ac_fn_c_check_header_mongrel "$LINENO" "ffi.h" "ac_cv_header_ffi_h" "$ac_includes_default"
-if test "x$ac_cv_header_ffi_h" = xyes; then :
-
-      save_CFLAGS=$CFLAGS
+    save_CFLAGS=$CFLAGS
 save_CPPFLAGS=$CPPFLAGS
 save_LDFLAGS=$LDFLAGS
 save_LIBS=$LIBS
 
 
+      CPPFLAGS="$CFLAGS $LIBFFI_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBFFI_LIBS"
+      ac_fn_c_check_header_mongrel "$LINENO" "ffi.h" "ac_cv_header_ffi_h" "$ac_includes_default"
+if test "x$ac_cv_header_ffi_h" = xyes; then :
+
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ffi_call in -lffi" >&5
 $as_echo_n "checking for ffi_call in -lffi... " >&6; }
 if ${ac_cv_lib_ffi_ffi_call+:} false; then :
@@ -12240,13 +12239,18 @@ $as_echo "$ac_cv_lib_ffi_ffi_call" >&6; }
 if test "x$ac_cv_lib_ffi_ffi_call" = xyes; then :
 
           have_libffi=yes
-          LIBFFI_LIBS="-lffi"
+          LIBFFI_CFLAGS=${LIBFFI_CFLAGS-""}
+          LIBFFI_LIBS=${LIBFFI_LIBS-"-lffi"}
 
 else
   have_libffi=no
 fi
 
 
+fi
+
+
+
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
 LDFLAGS=$save_LDFLAGS
@@ -12254,10 +12258,6 @@ LIBS=$save_LIBS
 
 
 
-fi
-
-
-
 else
 	LIBFFI_CFLAGS=$pkg_cv_LIBFFI_CFLAGS
 	LIBFFI_LIBS=$pkg_cv_LIBFFI_LIBS
@@ -12905,6 +12905,19 @@ case $ac_sys_system in #(
 esac
 
 
+
+
+  if test "$ac_sys_system" = "Emscripten" -a -z "$LIBSQLITE3_CFLAGS" -a -z "$LIBSQLITE3_LIBS"; then :
+
+    LIBSQLITE3_CFLAGS="-sUSE_SQLITE3"
+    LIBSQLITE3_LIBS="-sUSE_SQLITE3"
+
+fi
+
+
+
+
+
 pkg_failed=no
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for LIBSQLITE3" >&5
 $as_echo_n "checking for LIBSQLITE3... " >&6; }
@@ -16513,6 +16526,19 @@ fi
 
 
 
+
+
+  if test "$ac_sys_system" = "Emscripten" -a -z "$ZLIB_CFLAGS" -a -z "$ZLIB_LIBS"; then :
+
+    ZLIB_CFLAGS="-sUSE_ZLIB"
+    ZLIB_LIBS="-sUSE_ZLIB"
+
+fi
+
+
+
+
+
 pkg_failed=no
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for ZLIB" >&5
 $as_echo_n "checking for ZLIB... " >&6; }
@@ -16572,7 +16598,15 @@ fi
 	echo "$ZLIB_PKG_ERRORS" >&5
 
 
-  for ac_header in zlib.h
+  save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+    CPPFLAGS="$CFLAGS $ZLIB_CFLAGS"
+    LDFLAGS="$LDFLAGS $ZLIB_LIBS"
+    for ac_header in zlib.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "zlib.h" "ac_cv_header_zlib_h" "$ac_includes_default"
 if test "x$ac_cv_header_zlib_h" = xyes; then :
@@ -16580,13 +16614,8 @@ if test "x$ac_cv_header_zlib_h" = xyes; then :
 #define HAVE_ZLIB_H 1
 _ACEOF
 
-    save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for gzread in -lz" >&5
+      py_check_lib_save_LIBS=$LIBS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gzread in -lz" >&5
 $as_echo_n "checking for gzread in -lz... " >&6; }
 if ${ac_cv_lib_z_gzread+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -16623,11 +16652,26 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_z_gzread" >&5
 $as_echo "$ac_cv_lib_z_gzread" >&6; }
 if test "x$ac_cv_lib_z_gzread" = xyes; then :
+  have_zlib=yes
+else
+  have_zlib=no
+fi
+
+LIBS=$py_check_lib_save_LIBS
+
+
+else
+  have_zlib=no
+fi
 
-        have_zlib=yes
-        ZLIB_CFLAGS=${ZLIB_CFLAGS-""}
-        ZLIB_LIBS=${ZLIB_LIBS-"-lz"}
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for inflateCopy in -lz" >&5
+done
+
+    if test "x$have_zlib" = xyes; then :
+
+      ZLIB_CFLAGS=${ZLIB_CFLAGS-""}
+      ZLIB_LIBS=${ZLIB_LIBS-"-lz"}
+      py_check_lib_save_LIBS=$LIBS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for inflateCopy in -lz" >&5
 $as_echo_n "checking for inflateCopy in -lz... " >&6; }
 if ${ac_cv_lib_z_inflateCopy+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -16668,14 +16712,11 @@ if test "x$ac_cv_lib_z_inflateCopy" = xyes; then :
 
 fi
 
+LIBS=$py_check_lib_save_LIBS
 
-else
-
-        have_zlib=no
 
 fi
 
-
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
 LDFLAGS=$save_LDFLAGS
@@ -16683,18 +16724,19 @@ LIBS=$save_LIBS
 
 
 
-else
-  have_zlib=no
-fi
-
-done
-
-
 elif test $pkg_failed = untried; then
      	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 
-  for ac_header in zlib.h
+  save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+    CPPFLAGS="$CFLAGS $ZLIB_CFLAGS"
+    LDFLAGS="$LDFLAGS $ZLIB_LIBS"
+    for ac_header in zlib.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "zlib.h" "ac_cv_header_zlib_h" "$ac_includes_default"
 if test "x$ac_cv_header_zlib_h" = xyes; then :
@@ -16702,13 +16744,8 @@ if test "x$ac_cv_header_zlib_h" = xyes; then :
 #define HAVE_ZLIB_H 1
 _ACEOF
 
-    save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
-      { $as_echo "$as_me:${as_lineno-$LINENO}: checking for gzread in -lz" >&5
+      py_check_lib_save_LIBS=$LIBS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gzread in -lz" >&5
 $as_echo_n "checking for gzread in -lz... " >&6; }
 if ${ac_cv_lib_z_gzread+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -16745,11 +16782,26 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_z_gzread" >&5
 $as_echo "$ac_cv_lib_z_gzread" >&6; }
 if test "x$ac_cv_lib_z_gzread" = xyes; then :
+  have_zlib=yes
+else
+  have_zlib=no
+fi
+
+LIBS=$py_check_lib_save_LIBS
 
-        have_zlib=yes
-        ZLIB_CFLAGS=${ZLIB_CFLAGS-""}
-        ZLIB_LIBS=${ZLIB_LIBS-"-lz"}
-        { $as_echo "$as_me:${as_lineno-$LINENO}: checking for inflateCopy in -lz" >&5
+
+else
+  have_zlib=no
+fi
+
+done
+
+    if test "x$have_zlib" = xyes; then :
+
+      ZLIB_CFLAGS=${ZLIB_CFLAGS-""}
+      ZLIB_LIBS=${ZLIB_LIBS-"-lz"}
+      py_check_lib_save_LIBS=$LIBS
+{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for inflateCopy in -lz" >&5
 $as_echo_n "checking for inflateCopy in -lz... " >&6; }
 if ${ac_cv_lib_z_inflateCopy+:} false; then :
   $as_echo_n "(cached) " >&6
@@ -16790,14 +16842,11 @@ if test "x$ac_cv_lib_z_inflateCopy" = xyes; then :
 
 fi
 
+LIBS=$py_check_lib_save_LIBS
 
-else
-
-        have_zlib=no
 
 fi
 
-
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
 LDFLAGS=$save_LDFLAGS
@@ -16806,13 +16855,6 @@ LIBS=$save_LIBS
 
 
 else
-  have_zlib=no
-fi
-
-done
-
-
-else
 	ZLIB_CFLAGS=$pkg_cv_ZLIB_CFLAGS
 	ZLIB_LIBS=$pkg_cv_ZLIB_LIBS
         { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
@@ -16824,11 +16866,6 @@ $as_echo "yes" >&6; }
 
 fi
 
-if test "$have_zlib" = "yes" -a "$ac_sys_system" = "Emscripten" -a "$ZLIB_LIBS" = "-lz"; then
-  ZLIB_CFLAGS="-sUSE_ZLIB"
-  ZLIB_LIBS="-sUSE_ZLIB"
-fi
-
 if test "x$have_zlib" = xyes; then :
 
   BINASCII_CFLAGS="-DUSE_ZLIB_CRC32 $ZLIB_CFLAGS"
@@ -16837,6 +16874,19 @@ if test "x$have_zlib" = xyes; then :
 fi
 
 
+
+
+  if test "$ac_sys_system" = "Emscripten" -a -z "$BZIP2_CFLAGS" -a -z "$BZIP2_LIBS"; then :
+
+    BZIP2_CFLAGS="-sUSE_BZIP2"
+    BZIP2_LIBS="-sUSE_BZIP2"
+
+fi
+
+
+
+
+
 pkg_failed=no
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for BZIP2" >&5
 $as_echo_n "checking for BZIP2... " >&6; }
@@ -16896,7 +16946,15 @@ fi
 	echo "$BZIP2_PKG_ERRORS" >&5
 
 
-  for ac_header in bzlib.h
+  save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+    CPPFLAGS="$CFLAGS $BZIP2_CFLAGS"
+    LDFLAGS="$LDFLAGS $BZIP2_LIBS"
+    for ac_header in bzlib.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "bzlib.h" "ac_cv_header_bzlib_h" "$ac_includes_default"
 if test "x$ac_cv_header_bzlib_h" = xyes; then :
@@ -16904,12 +16962,6 @@ if test "x$ac_cv_header_bzlib_h" = xyes; then :
 #define HAVE_BZLIB_H 1
 _ACEOF
 
-    save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
       { $as_echo "$as_me:${as_lineno-$LINENO}: checking for BZ2_bzCompress in -lbz2" >&5
 $as_echo_n "checking for BZ2_bzCompress in -lbz2... " >&6; }
 if ${ac_cv_lib_bz2_BZ2_bzCompress+:} false; then :
@@ -16947,15 +16999,24 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_bz2_BZ2_bzCompress" >&5
 $as_echo "$ac_cv_lib_bz2_BZ2_bzCompress" >&6; }
 if test "x$ac_cv_lib_bz2_BZ2_bzCompress" = xyes; then :
+  have_bzip2=yes
+else
+  have_bzip2=no
+fi
 
-        have_bzip2=yes
-        BZIP2_CFLAGS=${BZIP2_CFLAGS-""}
-        BZIP2_LIBS=${BZIP2_LIBS-"-lbz2"}
 
 else
   have_bzip2=no
 fi
 
+done
+
+    if test "x$have_bzip2" = xyes; then :
+
+      BZIP2_CFLAGS=${BZIP2_CFLAGS-""}
+      BZIP2_LIBS=${BZIP2_LIBS-"-lbz2"}
+
+fi
 
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
@@ -16964,18 +17025,19 @@ LIBS=$save_LIBS
 
 
 
-else
-  have_bzip2=no
-fi
-
-done
-
-
 elif test $pkg_failed = untried; then
      	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 
-  for ac_header in bzlib.h
+  save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+    CPPFLAGS="$CFLAGS $BZIP2_CFLAGS"
+    LDFLAGS="$LDFLAGS $BZIP2_LIBS"
+    for ac_header in bzlib.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "bzlib.h" "ac_cv_header_bzlib_h" "$ac_includes_default"
 if test "x$ac_cv_header_bzlib_h" = xyes; then :
@@ -16983,12 +17045,6 @@ if test "x$ac_cv_header_bzlib_h" = xyes; then :
 #define HAVE_BZLIB_H 1
 _ACEOF
 
-    save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
       { $as_echo "$as_me:${as_lineno-$LINENO}: checking for BZ2_bzCompress in -lbz2" >&5
 $as_echo_n "checking for BZ2_bzCompress in -lbz2... " >&6; }
 if ${ac_cv_lib_bz2_BZ2_bzCompress+:} false; then :
@@ -17026,15 +17082,24 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_bz2_BZ2_bzCompress" >&5
 $as_echo "$ac_cv_lib_bz2_BZ2_bzCompress" >&6; }
 if test "x$ac_cv_lib_bz2_BZ2_bzCompress" = xyes; then :
+  have_bzip2=yes
+else
+  have_bzip2=no
+fi
 
-        have_bzip2=yes
-        BZIP2_CFLAGS=${BZIP2_CFLAGS-""}
-        BZIP2_LIBS=${BZIP2_LIBS-"-lbz2"}
 
 else
   have_bzip2=no
 fi
 
+done
+
+    if test "x$have_bzip2" = xyes; then :
+
+      BZIP2_CFLAGS=${BZIP2_CFLAGS-""}
+      BZIP2_LIBS=${BZIP2_LIBS-"-lbz2"}
+
+fi
 
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
@@ -17044,13 +17109,6 @@ LIBS=$save_LIBS
 
 
 else
-  have_bzip2=no
-fi
-
-done
-
-
-else
 	BZIP2_CFLAGS=$pkg_cv_BZIP2_CFLAGS
 	BZIP2_LIBS=$pkg_cv_BZIP2_LIBS
         { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
@@ -17058,12 +17116,6 @@ $as_echo "yes" >&6; }
 	have_bzip2=yes
 fi
 
-if test "$have_bzip2" = "yes" -a "$ac_sys_system" = "Emscripten" -a "$BZIP2_LIBS" = "-lbz2"; then
-  BZIP2_CFLAGS="-sUSE_BZIP2"
-  BZIP2_LIBS="-sUSE_BZIP2"
-fi
-
-
 
 pkg_failed=no
 { $as_echo "$as_me:${as_lineno-$LINENO}: checking for LIBLZMA" >&5
@@ -17124,7 +17176,15 @@ fi
 	echo "$LIBLZMA_PKG_ERRORS" >&5
 
 
-  for ac_header in lzma.h
+  save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+    CPPFLAGS="$CFLAGS $LIBLZMA_CFLAGS"
+    LDFLAGS="$LDFLAGS $LIBLZMA_LIBS"
+    for ac_header in lzma.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "lzma.h" "ac_cv_header_lzma_h" "$ac_includes_default"
 if test "x$ac_cv_header_lzma_h" = xyes; then :
@@ -17132,12 +17192,6 @@ if test "x$ac_cv_header_lzma_h" = xyes; then :
 #define HAVE_LZMA_H 1
 _ACEOF
 
-    save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
       { $as_echo "$as_me:${as_lineno-$LINENO}: checking for lzma_easy_encoder in -llzma" >&5
 $as_echo_n "checking for lzma_easy_encoder in -llzma... " >&6; }
 if ${ac_cv_lib_lzma_lzma_easy_encoder+:} false; then :
@@ -17175,15 +17229,24 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_lzma_lzma_easy_encoder" >&5
 $as_echo "$ac_cv_lib_lzma_lzma_easy_encoder" >&6; }
 if test "x$ac_cv_lib_lzma_lzma_easy_encoder" = xyes; then :
+  have_liblzma=yes
+else
+  have_liblzma=no
+fi
 
-        have_liblzma=yes
-        LIBLZMA_CFLAGS=${LIBLZMA_CFLAGS-""}
-        LIBLZMA_LIBS=${LIBLZMA_LIBS-"-llzma"}
 
 else
   have_liblzma=no
 fi
 
+done
+
+    if test "x$have_liblzma" = xyes; then :
+
+      LIBLZMA_CFLAGS=${LIBLZMA_CFLAGS-""}
+      LIBLZMA_LIBS=${LIBLZMA_LIBS-"-llzma"}
+
+fi
 
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
@@ -17192,18 +17255,19 @@ LIBS=$save_LIBS
 
 
 
-else
-  have_liblzma=no
-fi
-
-done
-
-
 elif test $pkg_failed = untried; then
      	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 
-  for ac_header in lzma.h
+  save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+    CPPFLAGS="$CFLAGS $LIBLZMA_CFLAGS"
+    LDFLAGS="$LDFLAGS $LIBLZMA_LIBS"
+    for ac_header in lzma.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "lzma.h" "ac_cv_header_lzma_h" "$ac_includes_default"
 if test "x$ac_cv_header_lzma_h" = xyes; then :
@@ -17211,12 +17275,6 @@ if test "x$ac_cv_header_lzma_h" = xyes; then :
 #define HAVE_LZMA_H 1
 _ACEOF
 
-    save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
       { $as_echo "$as_me:${as_lineno-$LINENO}: checking for lzma_easy_encoder in -llzma" >&5
 $as_echo_n "checking for lzma_easy_encoder in -llzma... " >&6; }
 if ${ac_cv_lib_lzma_lzma_easy_encoder+:} false; then :
@@ -17254,15 +17312,24 @@ fi
 { $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_lzma_lzma_easy_encoder" >&5
 $as_echo "$ac_cv_lib_lzma_lzma_easy_encoder" >&6; }
 if test "x$ac_cv_lib_lzma_lzma_easy_encoder" = xyes; then :
+  have_liblzma=yes
+else
+  have_liblzma=no
+fi
 
-        have_liblzma=yes
-        LIBLZMA_CFLAGS=${LIBLZMA_CFLAGS-""}
-        LIBLZMA_LIBS=${LIBLZMA_LIBS-"-llzma"}
 
 else
   have_liblzma=no
 fi
 
+done
+
+    if test "x$have_liblzma" = xyes; then :
+
+      LIBLZMA_CFLAGS=${LIBLZMA_CFLAGS-""}
+      LIBLZMA_LIBS=${LIBLZMA_LIBS-"-llzma"}
+
+fi
 
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
@@ -17272,13 +17339,6 @@ LIBS=$save_LIBS
 
 
 else
-  have_liblzma=no
-fi
-
-done
-
-
-else
 	LIBLZMA_CFLAGS=$pkg_cv_LIBLZMA_CFLAGS
 	LIBLZMA_LIBS=$pkg_cv_LIBLZMA_LIBS
         { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
@@ -20615,7 +20675,15 @@ fi
 	echo "$LIBREADLINE_PKG_ERRORS" >&5
 
 
-    for ac_header in readline/readline.h
+    save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+      CPPFLAGS="$CFLAGS $LIBREADLINE_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBREADLINE_LIBS"
+      for ac_header in readline/readline.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "readline/readline.h" "ac_cv_header_readline_readline_h" "$ac_includes_default"
 if test "x$ac_cv_header_readline_readline_h" = xyes; then :
@@ -20623,12 +20691,6 @@ if test "x$ac_cv_header_readline_readline_h" = xyes; then :
 #define HAVE_READLINE_READLINE_H 1
 _ACEOF
 
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for readline in -lreadline" >&5
 $as_echo_n "checking for readline in -lreadline... " >&6; }
 if ${ac_cv_lib_readline_readline+:} false; then :
@@ -20672,11 +20734,16 @@ if test "x$ac_cv_lib_readline_readline" = xyes; then :
           READLINE_LIBS=${LIBREADLINE_LIBS-"-lreadline"}
 
 else
+  with_readline=no
+fi
 
-          with_readline=no
 
+else
+  with_readline=no
 fi
 
+done
+
 
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
@@ -20685,18 +20752,19 @@ LIBS=$save_LIBS
 
 
 
-else
-  with_readline=no
-fi
-
-done
-
-
 elif test $pkg_failed = untried; then
      	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 
-    for ac_header in readline/readline.h
+    save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+      CPPFLAGS="$CFLAGS $LIBREADLINE_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBREADLINE_LIBS"
+      for ac_header in readline/readline.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "readline/readline.h" "ac_cv_header_readline_readline_h" "$ac_includes_default"
 if test "x$ac_cv_header_readline_readline_h" = xyes; then :
@@ -20704,12 +20772,6 @@ if test "x$ac_cv_header_readline_readline_h" = xyes; then :
 #define HAVE_READLINE_READLINE_H 1
 _ACEOF
 
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for readline in -lreadline" >&5
 $as_echo_n "checking for readline in -lreadline... " >&6; }
 if ${ac_cv_lib_readline_readline+:} false; then :
@@ -20753,11 +20815,16 @@ if test "x$ac_cv_lib_readline_readline" = xyes; then :
           READLINE_LIBS=${LIBREADLINE_LIBS-"-lreadline"}
 
 else
+  with_readline=no
+fi
 
-          with_readline=no
 
+else
+  with_readline=no
 fi
 
+done
+
 
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
@@ -20767,13 +20834,6 @@ LIBS=$save_LIBS
 
 
 else
-  with_readline=no
-fi
-
-done
-
-
-else
 	LIBREADLINE_CFLAGS=$pkg_cv_LIBREADLINE_CFLAGS
 	LIBREADLINE_LIBS=$pkg_cv_LIBREADLINE_LIBS
         { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
@@ -20849,7 +20909,15 @@ fi
 	echo "$LIBEDIT_PKG_ERRORS" >&5
 
 
-    for ac_header in editline/readline.h
+    save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+      CPPFLAGS="$CFLAGS $LIBEDIT_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBEDIT_LIBS"
+      for ac_header in editline/readline.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "editline/readline.h" "ac_cv_header_editline_readline_h" "$ac_includes_default"
 if test "x$ac_cv_header_editline_readline_h" = xyes; then :
@@ -20857,12 +20925,6 @@ if test "x$ac_cv_header_editline_readline_h" = xyes; then :
 #define HAVE_EDITLINE_READLINE_H 1
 _ACEOF
 
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for readline in -ledit" >&5
 $as_echo_n "checking for readline in -ledit... " >&6; }
 if ${ac_cv_lib_edit_readline+:} false; then :
@@ -20908,11 +20970,16 @@ if test "x$ac_cv_lib_edit_readline" = xyes; then :
           READLINE_LIBS=${LIBEDIT_LIBS-"-ledit"}
 
 else
+  with_readline=no
+fi
 
-          with_readline=no
 
+else
+  with_readline=no
 fi
 
+done
+
 
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
@@ -20921,18 +20988,19 @@ LIBS=$save_LIBS
 
 
 
-else
-  with_readline=no
-fi
-
-done
-
-
 elif test $pkg_failed = untried; then
      	{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
 $as_echo "no" >&6; }
 
-    for ac_header in editline/readline.h
+    save_CFLAGS=$CFLAGS
+save_CPPFLAGS=$CPPFLAGS
+save_LDFLAGS=$LDFLAGS
+save_LIBS=$LIBS
+
+
+      CPPFLAGS="$CFLAGS $LIBEDIT_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBEDIT_LIBS"
+      for ac_header in editline/readline.h
 do :
   ac_fn_c_check_header_mongrel "$LINENO" "editline/readline.h" "ac_cv_header_editline_readline_h" "$ac_includes_default"
 if test "x$ac_cv_header_editline_readline_h" = xyes; then :
@@ -20940,12 +21008,6 @@ if test "x$ac_cv_header_editline_readline_h" = xyes; then :
 #define HAVE_EDITLINE_READLINE_H 1
 _ACEOF
 
-      save_CFLAGS=$CFLAGS
-save_CPPFLAGS=$CPPFLAGS
-save_LDFLAGS=$LDFLAGS
-save_LIBS=$LIBS
-
-
         { $as_echo "$as_me:${as_lineno-$LINENO}: checking for readline in -ledit" >&5
 $as_echo_n "checking for readline in -ledit... " >&6; }
 if ${ac_cv_lib_edit_readline+:} false; then :
@@ -20991,11 +21053,16 @@ if test "x$ac_cv_lib_edit_readline" = xyes; then :
           READLINE_LIBS=${LIBEDIT_LIBS-"-ledit"}
 
 else
+  with_readline=no
+fi
 
-          with_readline=no
 
+else
+  with_readline=no
 fi
 
+done
+
 
 CFLAGS=$save_CFLAGS
 CPPFLAGS=$save_CPPFLAGS
@@ -21005,13 +21072,6 @@ LIBS=$save_LIBS
 
 
 else
-  with_readline=no
-fi
-
-done
-
-
-else
 	LIBEDIT_CFLAGS=$pkg_cv_LIBEDIT_CFLAGS
 	LIBEDIT_LIBS=$pkg_cv_LIBEDIT_LIBS
         { $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
diff --git a/configure.ac b/configure.ac
index c851659..1aa1c29 100644
--- a/configure.ac
+++ b/configure.ac
@@ -69,6 +69,28 @@ AC_DEFUN([PY_CHECK_FUNC],
   AS_VAR_POPDEF([py_define])
 ])
 
+dnl PY_CHECK_LIB(LIBRARY, FUNCTION, [ACTION-IF-FOUND], [ACTION-IF-NOT-FOUND], [OTHER-LIBRARIES])
+dnl Like AC_CHECK_LIB() but does not modify LIBS
+AC_DEFUN([PY_CHECK_LIB],
+[AS_VAR_COPY([py_check_lib_save_LIBS], [LIBS])]
+[AC_CHECK_LIB($1, $2, $3, $4, $5)]
+[AS_VAR_COPY([LIBS], [py_check_lib_save_LIBS])]
+)
+
+dnl PY_CHECK_EMSCRIPTEN_PORT(PKG_VAR, [EMPORT_ARGS])
+dnl Use Emscripten port unless user passes ${PKG_VAR}_CFLAGS
+dnl or ${PKG_VAR}_LIBS to configure.
+AC_DEFUN([PY_CHECK_EMSCRIPTEN_PORT], [
+  AS_VAR_PUSHDEF([py_cflags], [$1_CFLAGS])
+  AS_VAR_PUSHDEF([py_libs], [$1_LIBS])
+  AS_IF([test "$ac_sys_system" = "Emscripten" -a -z "$py_cflags" -a -z "$py_libs"], [
+    py_cflags="$2"
+    py_libs="$2"
+  ])
+  AS_VAR_POPDEF([py_cflags])
+  AS_VAR_POPDEF([py_libs])
+])
+
 AC_SUBST(BASECPPFLAGS)
 if test "$srcdir" != . -a "$srcdir" != "$(pwd)"; then
     # If we're building out-of-tree, we need to make sure the following
@@ -3371,12 +3393,12 @@ AS_VAR_IF([have_uuid], [missing], [
       AC_DEFINE([HAVE_UUID_H], [1])
       AC_DEFINE([HAVE_UUID_GENERATE_TIME_SAFE], [1])
     ], [
-      AC_CHECK_HEADERS([uuid/uuid.h], [
-        WITH_SAVE_ENV(
-          [AC_CHECK_LIB([uuid], [uuid_generate_time], [have_uuid=yes])
-        ])
-        WITH_SAVE_ENV([
-          AC_CHECK_LIB([uuid], [uuid_generate_time_safe], [
+      WITH_SAVE_ENV([
+        CPPFLAGS="$CFLAGS $LIBUUID_CFLAGS"
+        LDFLAGS="$LDFLAGS $LIBUUID_LIBS"
+        AC_CHECK_HEADERS([uuid/uuid.h], [
+          PY_CHECK_LIB([uuid], [uuid_generate_time], [have_uuid=yes])
+          PY_CHECK_LIB([uuid], [uuid_generate_time_safe], [
             have_uuid=yes
             AC_DEFINE([HAVE_UUID_GENERATE_TIME_SAFE], [1])
           ])
@@ -3602,11 +3624,14 @@ dnl detect libffi
 have_libffi=missing
 AS_VAR_IF([with_system_ffi], [yes], [
   PKG_CHECK_MODULES([LIBFFI], [libffi], [have_libffi=yes], [
-    AC_CHECK_HEADER([ffi.h], [
-      WITH_SAVE_ENV([
+    WITH_SAVE_ENV([
+      CPPFLAGS="$CFLAGS $LIBFFI_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBFFI_LIBS"
+      AC_CHECK_HEADER([ffi.h], [
         AC_CHECK_LIB([ffi], [ffi_call], [
           have_libffi=yes
-          LIBFFI_LIBS="-lffi"
+          LIBFFI_CFLAGS=${LIBFFI_CFLAGS-""}
+          LIBFFI_LIBS=${LIBFFI_LIBS-"-lffi"}
         ], [have_libffi=no])
       ])
     ])
@@ -3779,6 +3804,9 @@ AS_CASE([$ac_sys_system],
   [OSSAUDIODEV_LIBS=""]
 )
 
+dnl detect sqlite3 from Emscripten emport
+PY_CHECK_EMSCRIPTEN_PORT([LIBSQLITE3], [-sUSE_SQLITE3])
+
 dnl Check for SQLite library. Use pkg-config if available.
 PKG_CHECK_MODULES(
   [LIBSQLITE3], [sqlite3 >= 3.7.15], [], [
@@ -4788,64 +4816,63 @@ fi
 dnl Check for compression libraries
 AH_TEMPLATE([HAVE_ZLIB_COPY], [Define if the zlib library has inflateCopy])
 
+dnl detect zlib from Emscripten emport
+PY_CHECK_EMSCRIPTEN_PORT([ZLIB], [-sUSE_ZLIB])
+
 PKG_CHECK_MODULES([ZLIB], [zlib >= 1.2.0], [
   have_zlib=yes
   dnl zlib 1.2.0 (2003) added inflateCopy
   AC_DEFINE([HAVE_ZLIB_COPY], [1])
 ], [
-  AC_CHECK_HEADERS([zlib.h], [
-    WITH_SAVE_ENV([
-      AC_CHECK_LIB([z], [gzread], [
-        have_zlib=yes
-        ZLIB_CFLAGS=${ZLIB_CFLAGS-""}
-        ZLIB_LIBS=${ZLIB_LIBS-"-lz"}
-        AC_CHECK_LIB([z], [inflateCopy], [AC_DEFINE([HAVE_ZLIB_COPY], [1])])
-      ], [
-        have_zlib=no
-      ])
+  WITH_SAVE_ENV([
+    CPPFLAGS="$CFLAGS $ZLIB_CFLAGS"
+    LDFLAGS="$LDFLAGS $ZLIB_LIBS"
+    AC_CHECK_HEADERS([zlib.h], [
+      PY_CHECK_LIB([z], [gzread], [have_zlib=yes], [have_zlib=no])
+    ], [have_zlib=no])
+    AS_VAR_IF([have_zlib], [yes], [
+      ZLIB_CFLAGS=${ZLIB_CFLAGS-""}
+      ZLIB_LIBS=${ZLIB_LIBS-"-lz"}
+      PY_CHECK_LIB([z], [inflateCopy], [AC_DEFINE([HAVE_ZLIB_COPY], [1])])
     ])
-  ], [have_zlib=no])
+  ])
 ])
 
-if test "$have_zlib" = "yes" -a "$ac_sys_system" = "Emscripten" -a "$ZLIB_LIBS" = "-lz"; then
-  ZLIB_CFLAGS="-sUSE_ZLIB"
-  ZLIB_LIBS="-sUSE_ZLIB"
-fi
-
 dnl binascii can use zlib for optimized crc32.
 AS_VAR_IF([have_zlib], [yes], [
   BINASCII_CFLAGS="-DUSE_ZLIB_CRC32 $ZLIB_CFLAGS"
   BINASCII_LIBS="$ZLIB_LIBS"
 ])
 
+dnl detect bzip2 from Emscripten emport
+PY_CHECK_EMSCRIPTEN_PORT([BZIP2], [-sUSE_BZIP2])
+
 PKG_CHECK_MODULES([BZIP2], [bzip2], [have_bzip2=yes], [
-  AC_CHECK_HEADERS([bzlib.h], [
-    WITH_SAVE_ENV([
-      AC_CHECK_LIB([bz2], [BZ2_bzCompress], [
-        have_bzip2=yes
-        BZIP2_CFLAGS=${BZIP2_CFLAGS-""}
-        BZIP2_LIBS=${BZIP2_LIBS-"-lbz2"}
-      ], [have_bzip2=no])
+  WITH_SAVE_ENV([
+    CPPFLAGS="$CFLAGS $BZIP2_CFLAGS"
+    LDFLAGS="$LDFLAGS $BZIP2_LIBS"
+    AC_CHECK_HEADERS([bzlib.h], [
+      AC_CHECK_LIB([bz2], [BZ2_bzCompress], [have_bzip2=yes], [have_bzip2=no])
+    ], [have_bzip2=no])
+    AS_VAR_IF([have_bzip2], [yes], [
+      BZIP2_CFLAGS=${BZIP2_CFLAGS-""}
+      BZIP2_LIBS=${BZIP2_LIBS-"-lbz2"}
     ])
-  ], [have_bzip2=no])
+  ])
 ])
 
-if test "$have_bzip2" = "yes" -a "$ac_sys_system" = "Emscripten" -a "$BZIP2_LIBS" = "-lbz2"; then
-  BZIP2_CFLAGS="-sUSE_BZIP2"
-  BZIP2_LIBS="-sUSE_BZIP2"
-fi
-
-
 PKG_CHECK_MODULES([LIBLZMA], [liblzma], [have_liblzma=yes], [
-  AC_CHECK_HEADERS([lzma.h], [
-    WITH_SAVE_ENV([
-      AC_CHECK_LIB([lzma], [lzma_easy_encoder], [
-        have_liblzma=yes
-        LIBLZMA_CFLAGS=${LIBLZMA_CFLAGS-""}
-        LIBLZMA_LIBS=${LIBLZMA_LIBS-"-llzma"}
-      ], [have_liblzma=no])
+  WITH_SAVE_ENV([
+    CPPFLAGS="$CFLAGS $LIBLZMA_CFLAGS"
+    LDFLAGS="$LDFLAGS $LIBLZMA_LIBS"
+    AC_CHECK_HEADERS([lzma.h], [
+      AC_CHECK_LIB([lzma], [lzma_easy_encoder], [have_liblzma=yes], [have_liblzma=no])
+    ], [have_liblzma=no])
+    AS_VAR_IF([have_liblzma], [yes], [
+      LIBLZMA_CFLAGS=${LIBLZMA_CFLAGS-""}
+      LIBLZMA_LIBS=${LIBLZMA_LIBS-"-llzma"}
     ])
-  ], [have_liblzma=no])
+  ])
 ])
 
 PY_CHECK_FUNC([hstrerror], [#include <netdb.h>])
@@ -5812,17 +5839,17 @@ AS_VAR_IF([with_readline], [readline], [
     READLINE_CFLAGS=$LIBREADLINE_CFLAGS
     READLINE_LIBS=$LIBREADLINE_LIBS
   ], [
-    AC_CHECK_HEADERS([readline/readline.h], [
-      WITH_SAVE_ENV([
+    WITH_SAVE_ENV([
+      CPPFLAGS="$CFLAGS $LIBREADLINE_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBREADLINE_LIBS"
+      AC_CHECK_HEADERS([readline/readline.h], [
         AC_CHECK_LIB([readline], [readline], [
           LIBREADLINE=readline
           READLINE_CFLAGS=${LIBREADLINE_CFLAGS-""}
           READLINE_LIBS=${LIBREADLINE_LIBS-"-lreadline"}
-        ], [
-          with_readline=no
-        ])
-      ])
-    ], [with_readline=no])
+        ], [with_readline=no])
+      ], [with_readline=no])
+    ])
   ])
 ])
 
@@ -5833,18 +5860,18 @@ AS_VAR_IF([with_readline], [edit], [
     READLINE_CFLAGS=$LIBEDIT_CFLAGS
     READLINE_LIBS=$LIBEDIT_LIBS
   ], [
-    AC_CHECK_HEADERS([editline/readline.h], [
-      WITH_SAVE_ENV([
+    WITH_SAVE_ENV([
+      CPPFLAGS="$CFLAGS $LIBEDIT_CFLAGS"
+      LDFLAGS="$LDFLAGS $LIBEDIT_LIBS"
+      AC_CHECK_HEADERS([editline/readline.h], [
         AC_CHECK_LIB([edit], [readline], [
           LIBREADLINE=edit
           AC_DEFINE([WITH_EDITLINE], [1])
           READLINE_CFLAGS=${LIBEDIT_CFLAGS-""}
           READLINE_LIBS=${LIBEDIT_LIBS-"-ledit"}
-        ], [
-          with_readline=no
-        ])
-      ])
-    ], [with_readline=no])
+        ], [with_readline=no])
+      ], [with_readline=no])
+    ])
   ])
 ])