From: akamch@... Date: 2018-06-04T11:37:23+00:00 Subject: [ruby-core:87389] [Ruby trunk Bug#14816] Extension build failure on a system with musl libc Issue #14816 has been updated by akamch (Anatoly Kamchatnov). > I guess this is not our fault? Not entirely. Most likely it's nobody's fault but you can always blame autoconf :) Alpine's author thinks that "the configure script does not detect isnan/isinf as macros, call ruby devs". Autoconf's doc says ~~~ isinf isnan The C99 standard says that isinf and isnan are macros. On some systems just macros are available (e.g., HP-UX and Solaris 10), on some systems both macros and functions (e.g., glibc 2.3.2), and on some systems only functions (e.g., IRIX 6 and Solaris 9). In some cases these functions are declared in nonstandard headers like and defined in non-default libraries like -lm or -lsunmath. The C99 isinf and isnan macros work correctly with long double arguments, but pre-C99 systems that use functions typically assume double arguments. On such a system, isinf incorrectly returns true for a finite long double argument that is outside the range of double. The best workaround for these issues is to use gnulib modules isinf and isnan (see Gnulib). But a lighter weight solution involves code like the following. #include #ifndef isnan # define isnan(x) \ (sizeof (x) == sizeof (long double) ? isnan_ld (x) \ : sizeof (x) == sizeof (double) ? isnan_d (x) \ : isnan_f (x)) static inline int isnan_f (float x) { return x != x; } static inline int isnan_d (double x) { return x != x; } static inline int isnan_ld (long double x) { return x != x; } #endif #ifndef isinf # define isinf(x) \ (sizeof (x) == sizeof (long double) ? isinf_ld (x) \ : sizeof (x) == sizeof (double) ? isinf_d (x) \ : isinf_f (x)) static inline int isinf_f (float x) { return !isnan (x) && isnan (x - x); } static inline int isinf_d (double x) { return !isnan (x) && isnan (x - x); } static inline int isinf_ld (long double x) { return !isnan (x) && isnan (x - x); } #endif ~~~ https://www.gnu.org/software/autoconf/manual/autoconf.html#Function-Portability Looks like musl is not unlike HP-UX and Solaris 10 in that regard. The question is where one should fix this: some ruby routines around extconf.rb, gem in question, anywhere else? That I don't know, but the first option still seems plausible to me. ---------------------------------------- Bug #14816: Extension build failure on a system with musl libc https://bugs.ruby-lang.org/issues/14816#change-72375 * Author: akamch (Anatoly Kamchatnov) * Status: Open * Priority: Normal * Assignee: * Target version: * ruby -v: ruby 2.6.0preview2 (2018-05-31 trunk 63539) [x86_64-linux] * Backport: 2.3: UNKNOWN, 2.4: UNKNOWN, 2.5: UNKNOWN ---------------------------------------- Some extensions fail to build on a Linux with musl (Void Linux). Build of unf_ext is an example. isinf() and isnan() are defined as macros in musl: https://git.musl-libc.org/cgit/musl/tree/include/math.h https://github.com/gliderlabs/docker-alpine/issues/261 "Cannot build native extensions for unf_ext gem" seems to be a related issue. ~~~ $ gem install unf_ext Building native extensions. This could take a while... ERROR: Error installing unf_ext: ERROR: Failed to build gem native extension. current directory: /home/rev/.gem/ruby/2.6.0/gems/unf_ext-0.0.7.5/ext/unf_ext /home/rev/.rbenv/versions/2.6.0-preview2/bin/ruby -r ./siteconf20180603-29655-wgzu56.rb extconf.rb checking for -lstdc++... yes creating Makefile current directory: /home/rev/.gem/ruby/2.6.0/gems/unf_ext-0.0.7.5/ext/unf_ext make "DESTDIR=" clean current directory: /home/rev/.gem/ruby/2.6.0/gems/unf_ext-0.0.7.5/ext/unf_ext make "DESTDIR=" compiling unf.cc cc1plus: warning: command line option '-Wimplicit-int' is valid for C/ObjC but not for C++ cc1plus: warning: command line option '-Wdeclaration-after-statement' is valid for C/ObjC but not for C++ cc1plus: warning: command line option '-Wimplicit-function-declaration' is valid for C/ObjC but not for C++ In file included from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/defines.h:153:0, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/ruby.h:29, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby.h:33, from unf.cc:3: /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/missing.h:172:29: error: 'int isinf(double)' conflicts with a previous declaration RUBY_EXTERN int isinf(double); ^ In file included from /usr/include/c++/7.3/math.h:36:0, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/missing.h:23, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/defines.h:153, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/ruby.h:29, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby.h:33, from unf.cc:3: /usr/include/c++/7.3/cmath:599:3: note: previous declaration 'constexpr bool std::isinf(double)' isinf(double __x) ^~~~~ In file included from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/defines.h:153:0, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/ruby.h:29, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby.h:33, from unf.cc:3: /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/missing.h:179:29: error: 'int isnan(double)' conflicts with a previous declaration RUBY_EXTERN int isnan(double); ^ In file included from /usr/include/c++/7.3/math.h:36:0, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/missing.h:23, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/defines.h:153, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby/ruby.h:29, from /home/rev/.rbenv/versions/2.6.0-preview2/include/ruby-2.6.0/ruby.h:33, from unf.cc:3: /usr/include/c++/7.3/cmath:626:3: note: previous declaration 'constexpr bool std::isnan(double)' isnan(double __x) ^~~~~ cc1plus: warning: unrecognized command line option '-Wno-cast-function-type' cc1plus: warning: unrecognized command line option '-Wno-self-assign' cc1plus: warning: unrecognized command line option '-Wno-constant-logical-operand' cc1plus: warning: unrecognized command line option '-Wno-parentheses-equality' make: *** [Makefile:211: unf.o] Error 1 make failed, exit code 2 ~~~ -- https://bugs.ruby-lang.org/ Unsubscribe: