From d3a145655a78abac1fe9d24003ed4ed0cbad5676 Mon Sep 17 00:00:00 2001
From: gambas <g4mba5@gmail.com>
Date: Sat, 1 Sep 2018 20:05:44 +0200
Subject: [PATCH] Fix compilation of gb.pdf on old gcc, by checking if the
 '-std=c++11' flag is available.

[INTERPRETER]
* NEW: Write the name of optional libraries in the warning message displayed when not found.

[GB.PDF]
* BUG: Fix compilation of gb.pdf on old gcc, by checking if the '-std=c++11' flag is available.
---
 acinclude.m4           | 12 ++++++++++++
 gb.pdf/src/Makefile.am |  2 +-
 main/configure.ac      |  6 +++---
 3 files changed, 16 insertions(+), 4 deletions(-)

diff --git a/acinclude.m4 b/acinclude.m4
index 7f2513a91..a8f248d2e 100644
--- a/acinclude.m4
+++ b/acinclude.m4
@@ -346,6 +346,17 @@ AC_DEFUN([GB_INIT],
     AC_DEFINE(HAVE_GCC_LTO, 1, [Whether gcc supports -flto])
   fi
   
+  dnl ---- check for -std=c++11 compiler flag
+  
+  GB_CFLAGS_GCC_OPTION([-std=c++11],,
+    [
+      GB_CXXFLAGS_STD_CPP11=" -std=c11x"
+      have_gcc_std_c11x=yes
+    ])
+  
+  if test "$have_gcc_std_cpp11" = "yes"; then
+    AC_DEFINE(HAVE_GCC_STD_CPP11, 1, [Whether g++ supports -std=c++11])
+  fi
   
   dnl ---- Debug flags
 
@@ -376,6 +387,7 @@ AC_DEFUN([GB_INIT],
   AC_SUBST(AM_CXXFLAGS)
   AC_SUBST(AM_CXXFLAGS_OPT)
   AC_SUBST(GB_CFLAGS_LTO)
+  AC_SUBST(GB_CXXFLAGS_STD_CPP11)
 
   rm -f DISABLED DISABLED.*
 ])
diff --git a/gb.pdf/src/Makefile.am b/gb.pdf/src/Makefile.am
index f23192a43..eda3f0f36 100644
--- a/gb.pdf/src/Makefile.am
+++ b/gb.pdf/src/Makefile.am
@@ -5,7 +5,7 @@ gblib_LTLIBRARIES = gb.pdf.la
 
 gb_pdf_la_LIBADD = @POPPLER_LIB@
 gb_pdf_la_LDFLAGS = -module @LD_FLAGS@ @POPPLER_LDFLAGS@
-gb_pdf_la_CXXFLAGS = $(AM_CXXFLAGS) -std=c++11
+gb_pdf_la_CXXFLAGS = $(AM_CXXFLAGS) $(GB_CXXFLAGS_STD_CPP11)
 gb_pdf_la_CPPFLAGS = @POPPLER_INC@
 
 gb_pdf_la_SOURCES = main.h main.cpp \
diff --git a/main/configure.ac b/main/configure.ac
index ee06a6cb0..bd19bd3b8 100644
--- a/main/configure.ac
+++ b/main/configure.ac
@@ -22,7 +22,7 @@ GB_COMPONENT(
   [GB_FIND(libintl.$SHLIBEXT, /opt/local /usr/local /usr /, lib)],
   [-lintl],
   [],
-  [This library may be located inside the system C library, so you can ignore that warning...])
+  [Cannot find 'libintl' library. It may be located inside the system C library, so you can ignore that warning...])
 
 dnl ---- Remove DISABLED file that could have been generated before
 
@@ -36,7 +36,7 @@ GB_COMPONENT(
   [GB_FIND(libiconv.$SHLIBEXT, /opt/local /usr/local /usr, lib)],
   [-liconv],
   [],
-  [This library may be located inside the system C library, so you can ignore that warning...])
+  [Cannot find 'libiconv' library. It may be located inside the system C library, so you can ignore that warning...])
 
 dnl ---- Remove DISABLED file that could have been generated before
 
@@ -52,7 +52,7 @@ GB_COMPONENT(
   [GB_FIND(libgettextlib.$SHLIBEXT, /opt/local /usr/local /usr, lib)],
   [-lgettextlib],
   [],
-  [This library may be located inside the system C library, so you can ignore that warning...])
+  [Cannot find 'libgettextlib' library. It may be located inside the system C library, so you can ignore that warning...])
   
 fi