version.c: show +JIT when --jit is passed

in version output.
version.h: ditto
ruby.c: propagate option for it
common.mk: updated dependency for version.c

mjit.c: overwrites the RUBY_DESCRIPTION to have +JIT when --jit is passed

test/ruby/test_rubyoptions.rb: add test for them

Only `ruby --jit -v` will have "+JIT", but this is intentional.
This may not be convenient for debugging by ticket with `ruby -v`,
but it's convenient for benchmark tools that pass options (--jit)
when showing it. At least such behavior is planned for benchmark_driver.gem
and this behavior is designed for it. Other benchmark tools are
recommended to follow the behavior too if they show version.
RUBY_DESCRIPTION might be useful for it too.

The position of "+JIT" is changed from original proposal because other
platforms like JRuby and TruffleRuby end it with archtecture.
It's made similar to JRuby, but it's upper-cased because Matz made approval
for "+JIT" in the ticket.

Example:
$ ruby -v
ruby 2.6.0dev (2018-02-22 trunk 62529) [x86_64-linux]
$ ruby --jit -v
ruby 2.6.0dev (2018-02-22 trunk 62529) +JIT [x86_64-linux]

After --jit is made default in the future, this output may be removed.
So do not rely on this output if possible.

[Feature #14462]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@62530 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 10 insertions, 1 deletions

diff --git a/version.c b/version.c
index 4c7b1abb40..ec0dee91f0 100644
--- a/version.c
+++ b/version.c
@@ -11,6 +11,8 @@
 
 #include "ruby/ruby.h"
 #include "version.h"
+#include "vm_core.h"
+#include "mjit.h"
 #include <stdio.h>
 
 #ifndef EXIT_SUCCESS
@@ -31,6 +33,7 @@ const char ruby_release_date[] = RUBY_RELEASE_DATE;
 const char ruby_platform[] = RUBY_PLATFORM;
 const int ruby_patchlevel = RUBY_PATCHLEVEL;
 const char ruby_description[] = RUBY_DESCRIPTION;
+const char ruby_description_with_jit[] = RUBY_DESCRIPTION_WITH_JIT;
 const char ruby_copyright[] = RUBY_COPYRIGHT;
 const char ruby_engine[] = "ruby";
 
@@ -65,6 +68,7 @@ Init_version(void)
     rb_define_global_const("RUBY_REVISION", MKINT(revision));
     /*
      * The full ruby version string, like <tt>ruby -v</tt> prints'
+     * This might be overwritten by mjit_init().
      */
     rb_define_global_const("RUBY_DESCRIPTION", MKSTR(description));
     /*
@@ -86,7 +90,12 @@ Init_version(void)
 void
 ruby_show_version(void)
 {
-    PRINT(description);
+    if (mjit_opts.on) {
+        PRINT(description_with_jit);
+    }
+    else {
+        PRINT(description);
+    }
 #ifdef RUBY_LAST_COMMIT_TITLE
     fputs("last_commit=" RUBY_LAST_COMMIT_TITLE, stdout);
 #endif