https://github.com/gnustep/tools-make/pull/56

From 4b67844896e3d51bbd1b432eac443434a083dccf Mon Sep 17 00:00:00 2001
From: Niels Grewe <niels@zasta.de>
Date: Tue, 2 Sep 2025 07:23:29 +0200
Subject: [PATCH] feat: Support Swift's libBlocksRuntime

--- a/aclocal.m4
+++ b/aclocal.m4
@@ -294,3 +294,4 @@ m4_include([m4/gs_gcc_version.m4])
 m4_include([m4/gs_library_combo.m4])
 m4_include([m4/gs_objc_runtime.m4])
 m4_include([m4/gs_runtime_abi.m4])
+m4_include([m4/gs_blocks_support.m4])
--- a/config.make.in
+++ b/config.make.in
@@ -67,6 +67,7 @@ CLANG_CC = @CLANG_CC@
 OPTFLAG  = @CFLAGS@
 OBJCFLAGS= @OBJCFLAGS@
 OBJC_LIB_FLAG = @OBJC_LIB_FLAG@
+BLOCKS_LIB_FLAG = @BLOCKS_LIBS@
 CPPFLAGS = @CPPFLAGS@
 CPP      = @CPP@
 CCFLAGS  = @CXXFLAGS@
old mode 100755
new mode 100644
--- a/configure
+++ b/configure
@@ -645,6 +645,7 @@ OBJ_MERGE_CMD_FLAG
 USE_ARC
 ac_cv_objc_threaded
 objc_threaded
+BLOCKS_LIBS
 libobjc_LIBS
 libobjc_CFLAGS
 PKG_CONFIG_LIBDIR
@@ -5824,53 +5825,7 @@ fi
 
 
 else
-  if test "$OBJC_RUNTIME_LIB" = ng; then
-    #
-    # Detect compiler support for Blocks; perhaps someday -fblocks won't be
-    # required, in which case we'll need to change this.
-    #
-    saveCFLAGS="$CFLAGS"
-    CFLAGS="$CFLAGS -fblocks"
-    ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-
-cat confdefs.h - <<_ACEOF >conftest.$ac_ext
-/* end confdefs.h.  */
-
-int
-main (void)
-{
-(void)^{int i; i = 0; }();
-  ;
-  return 0;
-}
-_ACEOF
-if ac_fn_c_try_compile "$LINENO"
-then :
-
-      ac_cv_blocks="yes"
-
-else $as_nop
-
-      ac_cv_blocks="no"
 
-fi
-rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
-    CFLAGS="$saveCFLAGS"
-    ac_ext=c
-ac_cpp='$CPP $CPPFLAGS'
-ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
-ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
-ac_compiler_gnu=$ac_cv_c_compiler_gnu
-
-    if test "$ac_cv_blocks" = no; then
-      as_fn_error $? "Your compiler doesn't appear to support blocks. To fix this use the CC environment varibale to specify a different compiler (or use a different library-combo)" "$LINENO" 5;
-    fi
-  fi
   # Extract the first word of "ar", so it can be a program name with args.
 set dummy ar; ac_word=$2
 { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
@@ -8152,7 +8107,7 @@ printf "%s\n" "$gs_cv_libobjc_domain_ng" >&6; }
 
         if test ! x"$libobjc_LIBS" = x""; then
         OBJC_CPPFLAGS=$libobjc_CFLAGS
-        OBCJ_LDFLAGS=""
+        OBJC_LDFLAGS=""
         OBJC_FINAL_LIB_FLAG=$libobjc_LIBS
         elif test ! x"$gs_cv_libobjc_domain_ng" = x""; then
         if test x"$gs_cv_libobjc_domain_ng" = x"SYSTEM"; then
@@ -8219,7 +8174,8 @@ printf "%s\n" "$gs_cv_libobjc_domain_ng" >&6; }
 
 
 
-      ac_fn_c_check_func "$LINENO" "objc_test_capability" "ac_cv_func_objc_test_capability"
+
+ac_fn_c_check_func "$LINENO" "objc_test_capability" "ac_cv_func_objc_test_capability"
 if test "x$ac_cv_func_objc_test_capability" = xyes
 then :
 
@@ -8666,7 +8622,7 @@ printf "%s\n" "$gs_cv_libobjc_domain_dflt" >&6; }
 
         if test ! x"$libobjc_LIBS" = x""; then
         OBJC_CPPFLAGS=$libobjc_CFLAGS
-        OBCJ_LDFLAGS=""
+        OBJC_LDFLAGS=""
         OBJC_FINAL_LIB_FLAG=$libobjc_LIBS
         elif test ! x"$gs_cv_libobjc_domain_dflt" = x""; then
         if test x"$gs_cv_libobjc_domain_dflt" = x"SYSTEM"; then
@@ -8730,6 +8686,122 @@ printf "%s\n" "$gs_cv_libobjc_domain_dflt" >&6; }
 
 
 
+
+
+    BLOCKS_LIBS=""
+    if test "$OBJC_RUNTIME_LIB" = ng; then
+    #
+    # Detect compiler support for Blocks; perhaps someday -fblocks won't be
+    # required, in which case we'll need to change this.
+    #
+    saveCFLAGS="$CFLAGS"
+    CFLAGS="$CFLAGS -fblocks"
+
+    ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for blocks support in compiler" >&5
+printf %s "checking for blocks support in compiler... " >&6; }
+    cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+int
+main (void)
+{
+(void)^{int i; i = 0; }();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_compile "$LINENO"
+then :
+
+      ac_cv_blocks="yes"
+
+else $as_nop
+
+      ac_cv_blocks="no"
+
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam conftest.$ac_ext
+    { printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_blocks" >&5
+printf "%s\n" "$ac_cv_blocks" >&6; }
+    CFLAGS="$saveCFLAGS"
+    if test "$ac_cv_blocks" = yes; then
+      saveLIBS="$LIBS"
+      LIBS="$LIBS $OBJC_FINAL_LIB_FLAG"
+      ac_fn_c_check_func "$LINENO" "_Block_copy" "ac_cv_func__Block_copy"
+if test "x$ac_cv_func__Block_copy" = xyes
+then :
+
+fi
+
+      LIBS="$saveLIBS"
+      if test "$ac_cv_func__Block_copy" = no; then
+        { printf "%s\n" "$as_me:${as_lineno-$LINENO}: checking for _Block_copy in -lBlocksRuntime" >&5
+printf %s "checking for _Block_copy in -lBlocksRuntime... " >&6; }
+if test ${ac_cv_lib_BlocksRuntime__Block_copy+y}
+then :
+  printf %s "(cached) " >&6
+else $as_nop
+  ac_check_lib_save_LIBS=$LIBS
+LIBS="-lBlocksRuntime  $LIBS"
+cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h.  */
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+char _Block_copy ();
+int
+main (void)
+{
+return _Block_copy ();
+  ;
+  return 0;
+}
+_ACEOF
+if ac_fn_c_try_link "$LINENO"
+then :
+  ac_cv_lib_BlocksRuntime__Block_copy=yes
+else $as_nop
+  ac_cv_lib_BlocksRuntime__Block_copy=no
+fi
+rm -f core conftest.err conftest.$ac_objext conftest.beam \
+    conftest$ac_exeext conftest.$ac_ext
+LIBS=$ac_check_lib_save_LIBS
+fi
+{ printf "%s\n" "$as_me:${as_lineno-$LINENO}: result: $ac_cv_lib_BlocksRuntime__Block_copy" >&5
+printf "%s\n" "$ac_cv_lib_BlocksRuntime__Block_copy" >&6; }
+if test "x$ac_cv_lib_BlocksRuntime__Block_copy" = xyes
+then :
+  printf "%s\n" "#define HAVE_LIBBLOCKSRUNTIME 1" >>confdefs.h
+
+  LIBS="-lBlocksRuntime $LIBS"
+
+fi
+
+        if test "$ac_cv_lib_BlocksRuntime__Block_copy" = yes; then
+          BLOCKS_LIBS="-lBlocksRuntime"
+        else
+          as_fn_error $? "Your compiler supports blocks, but the symbols required for blocks support are found neither in libobjc nor in libBlocksRuntime. To fix this, recompile libobjc2 with an embedded blocks runtime, or install libBlocksRuntime/libdispatch with private headers." "$LINENO" 5
+        fi
+      fi
+    else
+      as_fn_error $? "Your compiler doesn't appear to support blocks. To fix this use the CC environment varibale to specify a different compiler (or use a different library-combo)" "$LINENO" 5;
+    fi
+    ac_ext=c
+ac_cpp='$CPP $CPPFLAGS'
+ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
+ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
+ac_compiler_gnu=$ac_cv_c_compiler_gnu
+
+  fi
+
+
 #--------------------------------------------------------------------
 # Check if libobjc was compiled with thread support.
 #--------------------------------------------------------------------
--- a/configure.ac
+++ b/configure.ac
@@ -228,25 +228,7 @@ if test "x$target" != "x$host"; then
   AC_CHECK_PROG(DLLTOOL, "${targetArgument}-dlltool", dnl
                          "${targetArgument}-dlltool", dlltool)
 else
-  if test "$OBJC_RUNTIME_LIB" = ng; then
-    #
-    # Detect compiler support for Blocks; perhaps someday -fblocks won't be
-    # required, in which case we'll need to change this.
-    #
-    saveCFLAGS="$CFLAGS"
-    CFLAGS="$CFLAGS -fblocks"
-    AC_LANG_PUSH(C)
-    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[(void)^{int i; i = 0; }();])], [
-      ac_cv_blocks="yes"
-    ], [
-      ac_cv_blocks="no"
-    ])
-    CFLAGS="$saveCFLAGS"
-    AC_LANG_POP(C)
-    if test "$ac_cv_blocks" = no; then
-      AC_MSG_ERROR([Your compiler doesn't appear to support blocks. To fix this use the CC environment varibale to specify a different compiler (or use a different library-combo)]);
-    fi
-  fi
+
   AC_CHECK_PROG(AR,      ar,      ar)
   AC_CHECK_PROG(DLLTOOL, dlltool, dlltool)
   AC_PROG_RANLIB
@@ -1147,7 +1129,7 @@ fi
 
 
 GS_CHECK_OBJC_RUNTIME()
-
+GS_BLOCKS_SUPPORT()
 #--------------------------------------------------------------------
 # Check if libobjc was compiled with thread support.
 #--------------------------------------------------------------------
--- a/library-combo.make
+++ b/library-combo.make
@@ -42,7 +42,7 @@ endif
 ifeq ($(OBJC_RUNTIME_LIB), ng)
   OBJC_LDFLAGS =
   OBJC_LIB_DIR =
-  OBJC_LIBS = $(OBJC_LIB_FLAG)
+  OBJC_LIBS = $(OBJC_LIB_FLAG) $(BLOCKS_LIB_FLAG)
   ifeq ($(RUNTIME_VERSION),)
     ifneq ($(DEFAULT_OBJC_RUNTIME_ABI),)
       RUNTIME_VERSION=$(DEFAULT_OBJC_RUNTIME_ABI)
--- /dev/null
+++ b/m4/gs_blocks_support.m4
@@ -0,0 +1,50 @@
+# SYNOPSIS
+#
+#   GS_BLOCKS_SUPPORT()
+#
+# DESCRIPTION
+#
+# This macro determines whether and how blocks are used
+#
+AC_DEFUN([GS_BLOCKS_SUPPORT],dnl
+  [
+    AC_REQUIRE([GS_LIBRARY_COMBO])
+    AC_REQUIRE([GS_CHECK_OBJC_RUNTIME])
+    BLOCKS_LIBS=""
+    if test "$OBJC_RUNTIME_LIB" = ng; then
+    #
+    # Detect compiler support for Blocks; perhaps someday -fblocks won't be
+    # required, in which case we'll need to change this.
+    #
+    saveCFLAGS="$CFLAGS"
+    CFLAGS="$CFLAGS -fblocks"
+
+    AC_LANG_PUSH(C)
+    AC_MSG_CHECKING([for blocks support in compiler])
+    AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[(void)^{int i; i = 0; }();])], [
+      ac_cv_blocks="yes"
+    ], [
+      ac_cv_blocks="no"
+    ])
+    AC_MSG_RESULT([$ac_cv_blocks])
+    CFLAGS="$saveCFLAGS"
+    if test "$ac_cv_blocks" = yes; then
+      saveLIBS="$LIBS"
+      LIBS="$LIBS $OBJC_FINAL_LIB_FLAG"
+      AC_CHECK_FUNC([_Block_copy])
+      LIBS="$saveLIBS"
+      if test "$ac_cv_func__Block_copy" = no; then
+        AC_CHECK_LIB([BlocksRuntime], [_Block_copy])
+        if test "$ac_cv_lib_BlocksRuntime__Block_copy" = yes; then
+          BLOCKS_LIBS="-lBlocksRuntime"
+        else
+          AC_MSG_ERROR([Your compiler supports blocks, but the symbols required for blocks support are found neither in libobjc nor in libBlocksRuntime. To fix this, recompile libobjc2 with an embedded blocks runtime, or install libBlocksRuntime/libdispatch with private headers.])
+        fi
+      fi
+    else
+      AC_MSG_ERROR([Your compiler doesn't appear to support blocks. To fix this use the CC environment varibale to specify a different compiler (or use a different library-combo)]);
+    fi
+    AC_LANG_POP(C)
+  fi
+  AC_SUBST(BLOCKS_LIBS)
+])
--- a/m4/gs_objc_runtime.m4
+++ b/m4/gs_objc_runtime.m4
@@ -164,7 +164,7 @@ AC_DEFUN([GS_OBJC_LIB_FLAG], [
 # Configure the installed Objective-C runtime, if it is installed. This sets up CFLAGS/LDFLAGS/LD_LIBRARY_PATH 
 # as required. Additionally, following variables are set after execution of this macro:
 # * OBJC_CPPFLAGS
-# * OBCJ_LDFLAGS
+# * OBJC_LDFLAGS
 # * OBJC_FINAL_LIB_FLAG
 # * OBJCRT
 #
@@ -185,7 +185,7 @@ AC_DEFUN([GS_CHECK_OBJC_RUNTIME], [
     dnl pkg-config makes it easy for us to configure the flags
     if test ! x"$libobjc_LIBS" = x""; then
         OBJC_CPPFLAGS=$libobjc_CFLAGS
-        OBCJ_LDFLAGS=""
+        OBJC_LDFLAGS=""
         OBJC_FINAL_LIB_FLAG=$libobjc_LIBS
     dnl we need to invest more smarts if
     elif test ! x"$gs_cv_libobjc_domain" = x""; then
@@ -279,4 +279,4 @@ AC_DEFUN([GS_CHECK_RUNTIME_ABI20_SUPPORT], [
             fi
     ])
     AS_VAR_SET([libobjc_SUPPORTS_ABI20], [${gs_cv_libobjc_abi_20}])
-])
\ No newline at end of file
+])