merge revision(s) 54492,54494,54495,54496,54499,54503: [Backport #12249]

	* math.c (ruby_tgamma): fix tgamma(-0.0) on mingw.
	  [ruby-core:74817] [Bug #12249]

	* math.c (ruby_lgamma_r): fix lgamma(-0.0) on mingw and OSX.

	* math.c (ruby_lgamma_r): mswin's lgamma_r also seems to be wrong.
	  cf. [Bug #12249]

	* math.c (ruby_lgamma_r): missing/lgamma_r.c is used on Windows,
	  since msvcrt does not provide it.

	* missing/lgamma_r.c (lgamma_r): fix lgamma(-0.0).
	  [ruby-core:74823] [Bug #12249]

	* configure.in (rb_cv_lgamma_r_m0): check if lgamma_r(-0.0)
	  returns negative infinity.  [Bug #12249]

	* math.c (ruby_lgamma_r): define by the configured result.

	* configure.in (rb_cv_lgamma_r_m0): fix the condition for
	  lgamma_r(-0.0).  [Bug #12249]


git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/branches/ruby_2_3@54643 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 35 insertions, 0 deletions

diff --git a/configure.in b/configure.in
index 1f714db1c9..1d083ea0a3 100644
--- a/configure.in
+++ b/configure.in
@@ -2438,6 +2438,41 @@ main(int argc, char **argv)
 ])
 AS_IF([test "x$rb_cv_atan2_inf_c99" = xyes], [AC_DEFINE(ATAN2_INF_C99)])
 
+AS_IF([test "x$ac_cv_func_lgamma_r" = xyes], [
+    AC_CACHE_CHECK(whether lgamma_r handles -0.0, rb_cv_lgamma_r_m0, [
+	AC_TRY_RUN([
+@%:@include <math.h>
+@%:@ifdef HAVE_UNISTD_H
+@%:@include <unistd.h>
+@%:@endif
+@%:@ifndef EXIT_SUCCESS
+@%:@define EXIT_SUCCESS 0
+@%:@endif
+@%:@ifndef EXIT_FAILURE
+@%:@define EXIT_FAILURE 1
+@%:@endif
+
+int
+main(int argc, char **argv)
+{
+    int sign;
+    double x = lgamma_r(-0.0, &sign);
+
+    /* should be [+inf, -1] */
+    if (x <= 0) return EXIT_FAILURE;
+    if (!isinf(x)) return EXIT_FAILURE;
+    if (sign != -1) return EXIT_FAILURE;
+    return EXIT_SUCCESS;
+}
+],
+	[rb_cv_lgamma_r_m0=yes],
+	[rb_cv_lgamma_r_m0=no],
+	[rb_cv_lgamma_r_m0=yes]
+	)
+    ])
+    AS_IF([test "x$rb_cv_lgamma_r_m0" = xno], [AC_DEFINE(LGAMMA_R_M0_FIX)])
+])
+
 # Some platform need -lrt for clock_gettime, but the other don't.
 if test x"$ac_cv_func_clock_gettime" != xyes; then
     # glibc 2.17 moves clock_* functions from librt to the main C library.