merge revision(s) d732bc51bdbfe7d66038731d42e01a511d13b5f8,633a1f15d8228236094ddee12e4e169d655ec49e,95f387f61a4a4ea92635da760b7de5b1e09bb84e,528a3a17977aa1843a26630c96635c3cb161e729,261569d4aac440f25de588cca365163ecf1124a2,e4a9e926f0fe0acf2fbe61da6e075a95d34be066,318be1cb2f9c6f04403c063a5618c6267012ee51,e1855100e46040e73630b378974c17764e0cccee,9cfa811b0f209d714f89fe0de6778c71f77556c7,b68dab866724aacc1cbc6b7d5e1f555dec092346: [Backport #17202]

	Revert "Revert "Revert "[ruby/fiddle] Use ffi_closure_free by
	 default. (#20)"""

	This reverts commit 87f6154bb4c67ca77ee353bb1fe25a922036c0e5.

	It turned out that the change fails to build on macOS

	https://rubyci.org/logs/rubyci.s3.amazonaws.com/osx1014/ruby-master/log/20200304T074503Z.fail.html.gz
	```
	+ make 'TESTS=--hide-skip -v fiddle' RUBYOPT=-w test-all
	dyld: lazy symbol binding failed: Symbol not found: _ffi_closure_alloc
	  Referenced from: /Users/hsbt/Documents/cb/tmp/build/20200304T074503Z/ruby/.ext/x86_64-darwin18/fiddle.bundle
	  Expected in: flat namespace

	dyld: Symbol not found: _ffi_closure_alloc
	  Referenced from: /Users/hsbt/Documents/cb/tmp/build/20200304T074503Z/ruby/.ext/x86_64-darwin18/fiddle.bundle
	  Expected in: flat namespace

	make: *** [yes-test-all] Abort trap: 6
	```

	[ruby/fiddle] Use ffi_closure_free if available

	[ruby/fiddle] ffi_closure_free is available in the bundled libffi

	[ruby/fiddle] use ffi_closure_alloc only with 3.2 or later

	[ruby/fiddle] always use ffi_closure_alloc on Windows

	Fixed a typo

	Show libffi version only if set

	ext/fiddle/extconf.rb: check if ffi_closure_alloc is available

	to define HAVE_FFI_CLOSURE_ALLOC.
	The macro is used in closure.c, so have_func check is needed.

	If pkg-config is not installed, extconf.rb fails to detect the version
	of libffi, and does not add "-DUSE_FFI_CLOSURE_ALLOC=1" even when system
	libffi version is >= 3.2.

	If USE_FFI_CLOSURE_ALLOC is not defined, closure.c attempts to check if
	HAVE_FFI_CLOSURE_ALLOC is defined or not, but have_func was removed with
	528a3a17977aa1843a26630c96635c3cb161e729, so the macro is always not
	defined.

	This resulted in this deprecation warning:

	https://rubyci.org/logs/rubyci.s3.amazonaws.com/ubuntu2004/ruby-master/log/20200512T123003Z.log.html.gz
	```
	compiling closure.c
	closure.c: In function 'initialize':
	closure.c:265:5: warning: 'ffi_prep_closure' is deprecated: use ffi_prep_closure_loc instead [-Wdeprecated-declarations]
	  265 |     result = ffi_prep_closure(pcl, cif, callback, (void *)self);
	      |     ^~~~~~
	In file included from ./fiddle.h:42,
	                 from closure.c:1:
	/usr/include/x86_64-linux-gnu/ffi.h:334:1: note: declared here
	  334 | ffi_prep_closure (ffi_closure*,
	      | ^~~~~~~~~~~~~~~~
	```

	Do not try ffi_closure_alloc if libffi is <= 3.1

	Maybe due to e1855100e46040e73630b378974c17764e0cccee, CentOS, RHEL, and
	Fedora CIs have started failing with SEGV.  Try to avoid
	ffi_closure_alloc on those environments.

	https://rubyci.org/logs/rubyci.s3.amazonaws.com/centos8/ruby-master/log/20200512T183004Z.fail.html.gz
	https://rubyci.org/logs/rubyci.s3.amazonaws.com/fedora32/ruby-master/log/20200512T183004Z.fail.html.gz
	https://rubyci.org/logs/rubyci.s3.amazonaws.com/rhel8/ruby-master/log/20200512T183003Z.fail.html.gz

	ext/fiddle/extconf.rb: Fix the condition of libffi <= 3.1

	ver is [3, 1, 0] which is not less then or equal to [3, 1]

3 files changed, 53 insertions, 11 deletions

diff --git a/ext/fiddle/closure.c b/ext/fiddle/closure.c
index b997e23f45..2044c836ea 100644
--- a/ext/fiddle/closure.c
+++ b/ext/fiddle/closure.c
@@ -13,11 +13,22 @@ typedef struct {
     ffi_type **argv;
 } fiddle_closure;
 
+#if defined(USE_FFI_CLOSURE_ALLOC)
+#elif !defined(HAVE_FFI_CLOSURE_ALLOC)
+# define USE_FFI_CLOSURE_ALLOC 0
+#else
+# define USE_FFI_CLOSURE_ALLOC 1
+#endif
+
 static void
 dealloc(void * ptr)
 {
     fiddle_closure * cls = (fiddle_closure *)ptr;
+#if USE_FFI_CLOSURE_ALLOC
     ffi_closure_free(cls->pcl);
+#else
+    munmap(cls->pcl, sizeof(*cls->pcl));
+#endif
     if (cls->argv) xfree(cls->argv);
     xfree(cls);
 }
@@ -191,7 +202,12 @@ allocate(VALUE klass)
     VALUE i = TypedData_Make_Struct(klass, fiddle_closure,
 	    &closure_data_type, closure);
 
+#if USE_FFI_CLOSURE_ALLOC
     closure->pcl = ffi_closure_alloc(sizeof(ffi_closure), &closure->code);
+#else
+    closure->pcl = mmap(NULL, sizeof(ffi_closure), PROT_READ | PROT_WRITE,
+        MAP_ANON | MAP_PRIVATE, -1, 0);
+#endif
 
     return i;
 }
@@ -238,8 +254,17 @@ initialize(int rbargc, VALUE argv[], VALUE self)
     if (FFI_OK != result)
 	rb_raise(rb_eRuntimeError, "error prepping CIF %d", result);
 
+#if USE_FFI_CLOSURE_ALLOC
     result = ffi_prep_closure_loc(pcl, cif, callback,
 		(void *)self, cl->code);
+#else
+    result = ffi_prep_closure(pcl, cif, callback, (void *)self);
+    cl->code = (void *)pcl;
+    i = mprotect(pcl, sizeof(*pcl), PROT_READ | PROT_EXEC);
+    if (i) {
+	rb_sys_fail("mprotect");
+    }
+#endif
 
     if (FFI_OK != result)
 	rb_raise(rb_eRuntimeError, "error prepping closure %d", result);
diff --git a/ext/fiddle/extconf.rb b/ext/fiddle/extconf.rb
index 5525b2c808..f8a94d41e7 100644
--- a/ext/fiddle/extconf.rb
+++ b/ext/fiddle/extconf.rb
@@ -7,12 +7,13 @@ bundle = enable_config('bundled-libffi')
 if ! bundle
   dir_config 'libffi'
 
-  pkg_config("libffi")
+  pkg_config("libffi") and
+    ver = pkg_config("libffi", "modversion")
 
   if have_header(ffi_header = 'ffi.h')
     true
   elsif have_header(ffi_header = 'ffi/ffi.h')
-    $defs.push(format('-DUSE_HEADER_HACKS'))
+    $defs.push('-DUSE_HEADER_HACKS')
     true
   end and (have_library('ffi') || have_library('libffi'))
 end or
@@ -27,20 +28,20 @@ begin
     Dir.glob("#{$srcdir}/libffi-*/").each{|dir| FileUtils.rm_rf(dir)}
     extlibs.run(["--cache=#{cache_dir}", ext_dir])
   end
-  libffi_dir = bundle != false &&
+  ver = bundle != false &&
         Dir.glob("#{$srcdir}/libffi-*/")
         .map {|n| File.basename(n)}
         .max_by {|n| n.scan(/\d+/).map(&:to_i)}
-  unless libffi_dir
+  unless ver
     raise "missing libffi. Please install libffi."
   end
 
-  srcdir = "#{$srcdir}/#{libffi_dir}"
+  srcdir = "#{$srcdir}/#{ver}"
   ffi_header = 'ffi.h'
   libffi = Struct.new(*%I[dir srcdir builddir include lib a cflags ldflags opt arch]).new
-  libffi.dir = libffi_dir
+  libffi.dir = ver
   if $srcdir == "."
-    libffi.builddir = "#{libffi_dir}/#{RUBY_PLATFORM}"
+    libffi.builddir = "#{ver}/#{RUBY_PLATFORM}"
     libffi.srcdir = "."
   else
     libffi.builddir = libffi.dir
@@ -51,6 +52,7 @@ begin
   libffi.a = "#{libffi.lib}/libffi_convenience.#{$LIBEXT}"
   nowarn = CONFIG.merge("warnflags"=>"")
   libffi.cflags = RbConfig.expand("$(CFLAGS)".dup, nowarn)
+  ver = ver[/libffi-(.*)/, 1]
 
   FileUtils.mkdir_p(libffi.dir)
   libffi.opt = CONFIG['configure_args'][/'(-C)'/, 1]
@@ -110,6 +112,21 @@ begin
   $INCFLAGS << " -I" << libffi.include
 end
 
+if ver
+  ver = ver.gsub(/-rc\d+/, '') # If ver contains rc version, just ignored.
+  ver = (ver.split('.').map(&:to_i) + [0,0])[0,3]
+  $defs.push(%{-DRUBY_LIBFFI_MODVERSION=#{ '%d%03d%03d' % ver }})
+  warn "libffi_version: #{ver.join('.')}"
+end
+
+case
+when $mswin, $mingw, (ver && (ver <=> [3, 2]) >= 0)
+  $defs << "-DUSE_FFI_CLOSURE_ALLOC=1"
+when (ver && (ver <=> [3, 2]) < 0)
+else
+  have_func('ffi_closure_alloc', ffi_header)
+end
+
 have_header 'sys/mman.h'
 
 if have_header "dlfcn.h"
@@ -134,7 +151,7 @@ types.each do |type, signed|
   if /^\#define\s+SIZEOF_#{type}\s+(SIZEOF_(.+)|\d+)/ =~ config
     if size = $2 and size != 'VOIDP'
       size = types.fetch(size) {size}
-      $defs << format("-DTYPE_%s=TYPE_%s", signed||type, size)
+      $defs << "-DTYPE_#{signed||type}=TYPE_#{size}"
     end
     if signed
       check_signedness(type.downcase, "stddef.h")
diff --git a/version.h b/version.h
index d1e50ce837..0f7d49e797 100644
--- a/version.h
+++ b/version.h
@@ -2,11 +2,11 @@
 # define RUBY_VERSION_MINOR RUBY_API_VERSION_MINOR
 #define RUBY_VERSION_TEENY 1
 #define RUBY_RELEASE_DATE RUBY_RELEASE_YEAR_STR"-"RUBY_RELEASE_MONTH_STR"-"RUBY_RELEASE_DAY_STR
-#define RUBY_PATCHLEVEL 133
+#define RUBY_PATCHLEVEL 134
 
 #define RUBY_RELEASE_YEAR 2020
-#define RUBY_RELEASE_MONTH 9
-#define RUBY_RELEASE_DAY 30
+#define RUBY_RELEASE_MONTH 10
+#define RUBY_RELEASE_DAY 1
 
 #include "ruby/version.h"