Stop defining `RUBY_ABI_VERSION` if released versions

As commented in include/ruby/internal/abi.h, since teeny versions of
Ruby should guarantee ABI compatibility, `RUBY_ABI_VERSION` has no role
in released versions of Ruby.

configure.ac

@@ -88,7 +88,9 @@ AC_SUBST(GIT)
 AC_SUBST(HAVE_GIT)
 
 eval `sed -n -e ['s/^@%:@define RUBY_[A-Z_]*VERSION_\([A-Z][A-Z][A-Z_0-9]*\) \([0-9][0-9]*\)$/\1=\2/p'] \
+      -e ['s/^@%:@define \(RUBY_ABI_VERSION\) \([0-9][0-9]*\).*/\1=\2/p'] \
       -e ['s/^@%:@define \(RUBY_PATCHLEVEL\) \(.*\)/\1=\2/p'] \
+     $srcdir/include/ruby/internal/abi.h \
      $srcdir/include/ruby/version.h $srcdir/version.h`
 for v in MAJOR MINOR TEENY; do
     AS_IF([eval "test \"\$$v\" = ''"], [
@@ -100,6 +102,9 @@ AC_SUBST(MINOR)
 AC_SUBST(TEENY)
 AC_SUBST(RUBY_API_VERSION, '$(MAJOR).$(MINOR)')
 AC_SUBST(RUBY_PROGRAM_VERSION, '$(MAJOR).$(MINOR).$(TEENY)')
+AS_CASE([$RUBY_PATCHLEVEL], [-*], [
+    AC_DEFINE_UNQUOTED(RUBY_ABI_VERSION, [${RUBY_ABI_VERSION}])
+], [RUBY_ABI_VERSION=])
 
 AS_IF([test "$program_prefix" = NONE], [
   program_prefix=
@@ -4118,6 +4123,7 @@ AS_CASE(["$ruby_version"],
 AS_IF([test ${RUBY_LIB_VERSION_STYLE+set}], [
     {
     echo "#define RUBY_LIB_VERSION_STYLE $RUBY_LIB_VERSION_STYLE"
+    echo '@%:@include "confdefs.h"'
     echo '#define STRINGIZE(x) x'
     test -f revision.h -o -f "${srcdir}/revision.h" || echo '#define RUBY_REVISION 0'
     echo '#include "version.h"'

ext/-test-/abi/extconf.rb

@@ -1,3 +1,4 @@
 # frozen_string_literal: false
+return unless RUBY_PATCHLEVEL < 0
 require_relative "../auto_ext.rb"
 auto_ext(inc: true)

include/ruby/internal/abi.h

@@ -1,6 +1,8 @@
 #ifndef RUBY_ABI_H
 #define RUBY_ABI_H
 
+#ifdef RUBY_ABI_VERSION /* should match the definition in config.h */
+
 /* This number represents Ruby's ABI version.
  *
  * In development Ruby, it should be bumped every time an ABI incompatible
@@ -19,7 +21,7 @@
  * - Backwards compatible refactors.
  * - Editing comments.
  *
- * In released versions of Ruby, this number should not be changed since teeny
+ * In released versions of Ruby, this number is not defined since teeny
  * versions of Ruby should guarantee ABI compatibility.
  */
 #define RUBY_ABI_VERSION 2
@@ -49,3 +51,5 @@ ruby_abi_version(void)
 #endif
 
 #endif
+
+#endif

test/-ext-/test_abi.rb

@@ -1,5 +1,7 @@
 # frozen_string_literal: true
 
+return unless RUBY_PATCHLEVEL < 0
+
 class TestABI < Test::Unit::TestCase
   def test_require_lib_with_incorrect_abi_on_dev_ruby
     omit "ABI is not checked" unless abi_checking_supported?

version.h

@@ -38,18 +38,25 @@
 #define RUBY_RELEASE_DAY_STR STRINGIZE(RUBY_RELEASE_DAY)
 #endif
 
+#ifdef RUBY_ABI_VERSION
+# define RUBY_ABI_VERSION_SUFFIX "+"STRINGIZE(RUBY_ABI_VERSION)
+#else
+# define RUBY_ABI_VERSION_SUFFIX ""
+#endif
 #if !defined RUBY_LIB_VERSION && defined RUBY_LIB_VERSION_STYLE
 # if RUBY_LIB_VERSION_STYLE == 3
 #   define RUBY_LIB_VERSION STRINGIZE(RUBY_API_VERSION_MAJOR)"."STRINGIZE(RUBY_API_VERSION_MINOR) \
-        "."STRINGIZE(RUBY_API_VERSION_TEENY)"+"STRINGIZE(RUBY_ABI_VERSION)
+        "."STRINGIZE(RUBY_API_VERSION_TEENY) RUBY_ABI_VERSION_SUFFIX
 # elif RUBY_LIB_VERSION_STYLE == 2
 #   define RUBY_LIB_VERSION STRINGIZE(RUBY_API_VERSION_MAJOR)"."STRINGIZE(RUBY_API_VERSION_MINOR) \
-    "+"STRINGIZE(RUBY_ABI_VERSION)
+        RUBY_ABI_VERSION_SUFFIX
 # endif
 #endif
 
 #if RUBY_PATCHLEVEL == -1
 #define RUBY_PATCHLEVEL_STR "dev"
+#elif defined RUBY_ABI_VERSION
+#error RUBY_ABI_VERSION is defined in non-development branch
 #else
 #define RUBY_PATCHLEVEL_STR ""
 #endif

win32/Makefile.sub

@@ -148,7 +148,10 @@ PLATFORM_DIR = win32
 arch = $(ARCH)-$(PLATFORM)
 sitearch = $(ARCH)-$(RT)
 !if !defined(ruby_version)
-ruby_version = $(MAJOR).$(MINOR).0+$(ABI_VERSION)
+ruby_version = $(MAJOR).$(MINOR).0
+!endif
+!if defined(ABI_VERSION)
+ruby_version = $(ruby_version)+$(ABI_VERSION)
 !endif
 !if !defined(RUBY_VERSION_NAME)
 RUBY_VERSION_NAME = $(RUBY_BASE_NAME)-$(ruby_version)
@@ -624,6 +627,9 @@ $(CONFIG_H): $(MKFILES) $(srcdir)/win32/Makefile.sub $(win_srcdir)/Makefile.sub
 #endif
 !endif
 #define RUBY_MSVCRT_VERSION $(RT_VER)
+!if defined(ABI_VERSION)
+#define RUBY_ABI_VERSION $(ABI_VERSION)
+!endif
 #define STDC_HEADERS 1
 #define HAVE_SYS_TYPES_H 1
 #define HAVE_SYS_STAT_H 1

win32/setup.mak

@@ -178,6 +178,7 @@ main(void)
 -version-: nul verconf.mk
 
 verconf.mk: nul
+	@findstr /R /C:"^#define RUBY_ABI_VERSION " $(srcdir:/=\)\include\ruby\internal\abi.h > $(@)
 	@$(CPP) -I$(srcdir) -I$(srcdir)/include <<"Creating $(@)" > $(*F).bat && cmd /c $(*F).bat > $(@)
 @echo off
 #define RUBY_REVISION 0
@@ -198,8 +199,9 @@ echo RUBY_RELEASE_DAY = %ruby_release_day:~-2%
 echo MAJOR = RUBY_VERSION_MAJOR
 echo MINOR = RUBY_VERSION_MINOR
 echo TEENY = RUBY_VERSION_TEENY
-echo ABI_VERSION = RUBY_ABI_VERSION
 #if defined RUBY_PATCHLEVEL && RUBY_PATCHLEVEL < 0
+#include "$(@F)"
+echo ABI_VERSION = RUBY_ABI_VERSION
 #endif
 set /a MSC_VER = _MSC_VER
 #if _MSC_VER >= 1920