Ruby

Imported from #3330

うっかりruby-listに投げてしまったきしもとです

[ruby-list:47092] で振ってみた話題に関係して、なのですが（ツリーになりませんでしたが）、
mkmf に C++ のヘッダをチェックする機能を追加するパッチです。

Index: configure.in =================================================================== --- configure.in	(revision 27940) +++ configure.in	(working copy) @@ -243,6 +243,7 @@ fi AC_PROG_CC AC_PROG_CXX +AC_PROG_CXXCPP  AC_PROG_GCC_TRADITIONAL AC_SUBST(GCC) if test "$GCC" = yes; then Index: lib/mkmf.rb =================================================================== --- lib/mkmf.rb	(revision 27940) +++ lib/mkmf.rb	(working copy) @@ -408,6 +408,14 @@ conf) end  +def cxxcpp_command(outfile, opt="") + conf = RbConfig::CONFIG.merge('hdrdir' => $hdrdir.quote, 'srcdir' => $srcdir.quote, + 'arch_hdrdir' => "#$arch_hdrdir", + 'top_srcdir' => $top_srcdir.quote) + RbConfig::expand("$(CXXCPP) #$INCFLAGS #$CPPFLAGS #$CXXFLAGS #{opt} #{CONFTEST_C} #{outfile}", + conf) +end +  def libpathflag(libpath=$DEFLIBPATH|$LIBPATH) libpath.map{|x| case x @@ -454,8 +462,15 @@ rm_f "conftest*" end  +def try_cxxcpp(src, opt="", &b) + try_do(src, cxxcpp_command(CPPOUTFILE, opt), &b) +ensure + rm_f "conftest*" +end +  class Object alias_method :try_header, (config_string('try_header') || :try_cpp) + alias_method :try_cxx_header, (config_string('try_cxx_header') || :try_cxxcpp)  end   def cpp_include(header) @@ -840,6 +855,24 @@ end end  +# Returns whether or not the given C plus plus +header+ file can be found on +# your system. If found, a macro is passed as a preprocessor constant to the +# compiler using the header file name, in uppercase, prepended with 'HAVE_'. +# +# For example, if have_header('foo.h') returned true, then the HAVE_FOO_H +# preprocessor macro would be passed to the compiler. +# +def have_cxx_header(header, preheaders = nil, &b) + checking_for header do + if try_cxx_header(cpp_include(preheaders)+cpp_include(header), &b) + $defs.push(format("-DHAVE_%s", header.tr_cpp)) + true + else + false + end + end +end +  # Instructs mkmf to search for the given +header+ in any of the +paths+ # provided, and returns whether or not it was found in those paths. # @@ -867,6 +900,33 @@ end end  +# Instructs mkmf to search for the given C plus plus +header+ in any of the +# +paths+ provided, and returns whether or not it was found in those paths. +# +# If the header is found then the path it was found on is added to the list +# of included directories that are sent to the compiler (via the -I switch). +# +def find_cxx_header(header, *paths) + message = checking_message(header, paths) + header = cpp_include(header) + checking_for message do + if try_cxx_header(header) + true + else + found = false + paths.each do |dir| + opt = "-I#{dir}".quote + if try_cxx_header(header, opt) + $INCFLAGS << " " << opt + found = true + break + end + end + found + end + end +end +  # Returns whether or not the struct of type +type+ contains +member+. If # it does not, or the struct type can't be found, then false is returned. You # may optionally specify additional +headers+ in which to look for the struct 

望み薄なので一旦閉じます。
今でも必要とお思いでしたら、議論を進める材料（lang: "C++" の方針でのパッチとか）を用意すると良いかも知れません。