| From 93582ad85ef48c18ac12f00a9a9e124989b1fcab Mon Sep 17 00:00:00 2001 |
| From: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> |
| Date: Fri, 1 May 2015 12:52:18 +0200 |
| Subject: [PATCH] Link against libm when needed |
| |
| In certain C libraries (e.g uClibc), isnan() and related functions are |
| implemented in libm, so json-c needs to link against it. This commit |
| therefore adds an AC_TRY_LINK() test to check whether a program |
| calling isnan() can be properly linked with no special flags. If not, |
| we assume linking against libm is needed. |
| |
| The json-c.pc.in file is also adjusted so that in the case of static |
| linking against json-c, -lm is also used. |
| |
| Signed-off-by: Thomas Petazzoni <thomas.petazzoni@free-electrons.com> |
| --- |
| Upstream-Status: Backport |
| |
| configure.ac | 4 ++++ |
| json-c.pc.in | 3 ++- |
| 2 files changed, 6 insertions(+), 1 deletion(-) |
| |
| diff --git a/configure.ac b/configure.ac |
| index c50f81b..30e7174 100644 |
| --- a/configure.ac |
| +++ b/configure.ac |
| @@ -50,6 +50,10 @@ AC_CHECK_DECLS([isinf], [], [], [[#include <math.h>]]) |
| AC_CHECK_DECLS([_isnan], [], [], [[#include <float.h>]]) |
| AC_CHECK_DECLS([_finite], [], [], [[#include <float.h>]]) |
| |
| +if test "$ac_cv_have_decl_isnan" = "yes" ; then |
| + AC_TRY_LINK([#include <math.h>], [float f = 0.0; return isnan(f)], [], [LIBS="$LIBS -lm"]) |
| +fi |
| + |
| #check if .section.gnu.warning accepts long strings (for __warn_references) |
| AC_LANG_PUSH([C]) |
| |
| diff --git a/json-c.pc.in b/json-c.pc.in |
| index 037739d..05bfbc8 100644 |
| --- a/json-c.pc.in |
| +++ b/json-c.pc.in |
| @@ -6,6 +6,7 @@ includedir=@includedir@ |
| Name: json-c |
| Description: JSON implementation in C |
| Version: @VERSION@ |
| -Requires: |
| +Requires: |
| +Libs.private: @LIBS@ |
| Libs: -L${libdir} -ljson-c |
| Cflags: -I${includedir}/json-c |
| -- |
| 2.8.1 |
| |