>From 9ef2e6d2053ea4d0068ecc1761f2ec81d4971790 Mon Sep 17 00:00:00 2001
From: Bruno Haible <address@hidden>
Date: Sat, 17 Dec 2016 20:48:34 +0100
Subject: [PATCH 18/20] tanf: Avoid redefinition error on MSVC.

* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Define REPLACE_TANF.
* m4/tanf.m4 (gl_FUNC_TANF): Set REPLACE_TANF to 1 if the function
may be defined as an inline function.
* modules/math (Makefile.am): Substitute REPLACE_TANF.
* lib/math.in.h (tanf): Override if REPLACE_TANF is 1.
---
 ChangeLog     |  9 +++++++++
 lib/math.in.h | 15 ++++++++++++---
 m4/math_h.m4  |  1 +
 m4/tanf.m4    |  6 +++++-
 modules/math  |  1 +
 5 files changed, 28 insertions(+), 4 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index a6593b1..f16b24e 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,5 +1,14 @@
 2016-12-17  Bruno Haible  <address@hidden>
 
+	tanf: Avoid redefinition error on MSVC.
+	* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Define REPLACE_TANF.
+	* m4/tanf.m4 (gl_FUNC_TANF): Set REPLACE_TANF to 1 if the function
+	may be defined as an inline function.
+	* modules/math (Makefile.am): Substitute REPLACE_TANF.
+	* lib/math.in.h (tanf): Override if REPLACE_TANF is 1.
+
+2016-12-17  Bruno Haible  <address@hidden>
+
 	sqrtf: Avoid redefinition error on MSVC.
 	* m4/math_h.m4 (gl_MATH_H_DEFAULTS): Define REPLACE_SQRTF.
 	* m4/sqrtf.m4 (gl_FUNC_SQRTF): Set REPLACE_SQRTF to 1 if the function
diff --git a/lib/math.in.h b/lib/math.in.h
index 842a636..44b4e88 100644
--- a/lib/math.in.h
+++ b/lib/math.in.h
@@ -2004,11 +2004,20 @@ _GL_WARN_ON_USE (sqrtl, "sqrtl is unportable - "
 
 
 #if @GNULIB_TANF@
-# if address@hidden@
-#  undef tanf
+# if @REPLACE_TANF@
+#  if !(defined __cplusplus && defined GNULIB_NAMESPACE)
+#   undef tanf
+#   define tanf rpl_tanf
+#  endif
+_GL_FUNCDECL_RPL (tanf, float, (float x));
+_GL_CXXALIAS_RPL (tanf, float, (float x));
+# else
+#  if address@hidden@
+#   undef tanf
 _GL_FUNCDECL_SYS (tanf, float, (float x));
-# endif
+#  endif
 _GL_CXXALIAS_SYS (tanf, float, (float x));
+# endif
 _GL_CXXALIASWARN (tanf);
 #elif defined GNULIB_POSIXCHECK
 # undef tanf
diff --git a/m4/math_h.m4 b/m4/math_h.m4
index cb41593..01e23ad 100644
--- a/m4/math_h.m4
+++ b/m4/math_h.m4
@@ -326,6 +326,7 @@ AC_DEFUN([gl_MATH_H_DEFAULTS],
   REPLACE_SINHF=0;             AC_SUBST([REPLACE_SINHF])
   REPLACE_SQRTF=0;             AC_SUBST([REPLACE_SQRTF])
   REPLACE_SQRTL=0;             AC_SUBST([REPLACE_SQRTL])
+  REPLACE_TANF=0;              AC_SUBST([REPLACE_TANF])
   REPLACE_TRUNC=0;             AC_SUBST([REPLACE_TRUNC])
   REPLACE_TRUNCF=0;            AC_SUBST([REPLACE_TRUNCF])
   REPLACE_TRUNCL=0;            AC_SUBST([REPLACE_TRUNCL])
diff --git a/m4/tanf.m4 b/m4/tanf.m4
index fe48da5..92a5f23 100644
--- a/m4/tanf.m4
+++ b/m4/tanf.m4
@@ -1,4 +1,4 @@
-# tanf.m4 serial 2
+# tanf.m4 serial 3
 dnl Copyright (C) 2011-2016 Free Software Foundation, Inc.
 dnl This file is free software; the Free Software Foundation
 dnl gives unlimited permission to copy and/or distribute it,
@@ -22,6 +22,10 @@ AC_DEFUN([gl_FUNC_TANF],
     TANF_LIBM="$TAN_LIBM"
   else
     HAVE_TANF=0
+    dnl If the function is declared but does not appear to exist, it may be
+    dnl defined as an inline function. In order to avoid a conflict, we have
+    dnl to define rpl_tanf, not tanf.
+    AC_CHECK_DECLS([tanf], [REPLACE_TANF=1], , [[#include <math.h>]])
     TANF_LIBM="$TAN_LIBM"
   fi
   AC_SUBST([TANF_LIBM])
diff --git a/modules/math b/modules/math
index a22d369..317e688 100644
--- a/modules/math
+++ b/modules/math
@@ -296,6 +296,7 @@ math.h: math.in.h $(top_builddir)/config.status $(CXXDEFS_H) $(ARG_NONNULL_H) $(
 	      -e 's|@''REPLACE_SINHF''@|$(REPLACE_SINHF)|g' \
 	      -e 's|@''REPLACE_SQRTF''@|$(REPLACE_SQRTF)|g' \
 	      -e 's|@''REPLACE_SQRTL''@|$(REPLACE_SQRTL)|g' \
+	      -e 's|@''REPLACE_TANF''@|$(REPLACE_TANF)|g' \
 	      -e 's|@''REPLACE_TRUNC''@|$(REPLACE_TRUNC)|g' \
 	      -e 's|@''REPLACE_TRUNCF''@|$(REPLACE_TRUNCF)|g' \
 	      -e 's|@''REPLACE_TRUNCL''@|$(REPLACE_TRUNCL)|g' \
-- 
2.6.4