[Buildroot] [PATCH 2/2] host-m4: fix build when -std=gnu99 and inline functions are used

[Lada Trimasova <Lada.Trimasova@synopsys.com>]

A lot of the glibc header files use extern inline, which causes
GCC to emit a symbol for each extern inline functions and it causes
functions multiple definition error when "-std=gnu99" is used.
To fix this problem it's necessary to use "-fgnu89-inline" option which
tells GCC to use the traditional GNU semantics for inline functions when
in C99 mode.

Signed-off-by: Lada Trimasova <ltrimas@synopsys.com>
Cc: Alexey Brodkin <abrodkin@synopsys.com>
Cc: Thomas Petazzoni <thomas.petazzoni@free-electrons.com>
Cc: Peter Korsgaard <peter@korsgaard.com>
---
 package/m4/m4.mk | 1 +
 1 file changed, 1 insertion(+)

diff --git a/package/m4/m4.mk b/package/m4/m4.mk
index 9b5d2d1..2644bb1 100644
--- a/package/m4/m4.mk
+++ b/package/m4/m4.mk
@@ -10,5 +10,6 @@ M4_SITE = $(BR2_GNU_MIRROR)/m4
 M4_LICENSE = GPLv3+
 M4_LICENSE_FILES = COPYING
 HOST_M4_CONF_OPTS = --disable-static
+HOST_M4_MAKE_OPTS = CFLAGS="-fgnu89-inline"
 
 $(eval $(host-autotools-package))
-- 
2.5.0