From 07d66da57b7829fca938d7e3c5c4b47a981b1d17 Mon Sep 17 00:00:00 2001
From: Lovell Fuller <github@lovell.info>
Date: Wed, 28 Sep 2016 21:40:30 +0100
Subject: [PATCH] Auto-detect C++11 ABI version, remove --sharp-cxx11 flag

---
 binding.gyp       | 15 ++++++++++-----
 docs/changelog.md |  2 ++
 docs/install.md   | 19 +++++--------------
 3 files changed, 17 insertions(+), 19 deletions(-)

diff --git a/binding.gyp b/binding.gyp
index e96cc5b1..bc7e8e74 100644
--- a/binding.gyp
+++ b/binding.gyp
@@ -51,7 +51,6 @@
     ],
     # Nested variables "pattern" borrowed from http://src.chromium.org/viewvc/chrome/trunk/src/build/common.gypi
     'variables': {
-      'sharp_cxx11%': '0',
       'variables': {
         'variables': {
           'conditions': [
@@ -92,10 +91,6 @@
       'src/sharp.cc',
       'src/utilities.cc'
     ],
-    'defines': [
-      '_GLIBCXX_USE_CXX11_ABI=<(sharp_cxx11)',
-      '_ALLOW_KEYWORD_MACROS'
-    ],
     'include_dirs': [
       '<!(node -e "require(\'nan\')")'
     ],
@@ -109,6 +104,10 @@
           }, {
             'libraries': ['<!@(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --libs vips-cpp)']
           }]
+        ],
+        'defines': [
+          # Inspect libvips-cpp.so to determine which C++11 ABI version was used and set _GLIBCXX_USE_CXX11_ABI accordingly. This is quite horrible.
+          '_GLIBCXX_USE_CXX11_ABI=<!(if readelf -Ws "$(PKG_CONFIG_PATH="<(pkg_config_path)" pkg-config --libs-only-L vips-cpp | cut -c 3-)/libvips-cpp.so" | c++filt | grep -qF __cxx11;then echo "1";else echo "0";fi)'
         ]
       }, {
         # Attempt to download pre-built libvips and install locally within node_modules
@@ -119,6 +118,9 @@
         ],
         'conditions': [
           ['OS == "win"', {
+            'defines': [
+              '_ALLOW_KEYWORD_MACROS'
+            ],
             'libraries': [
               '../lib/libvips.lib',
               '../lib/libglib-2.0.lib',
@@ -142,6 +144,9 @@
             'variables': {
               'download_vips': '<!(LDD_VERSION="<!(ldd --version 2>&1 || true)" node -e "require(\'./binding\').download_vips()")'
             },
+            'defines': [
+              '_GLIBCXX_USE_CXX11_ABI=0'
+            ],
             'libraries': [
               '../lib/libvips-cpp.so',
               '../lib/libvips.so',
diff --git a/docs/changelog.md b/docs/changelog.md
index 2e709b2e..abe4f078 100644
--- a/docs/changelog.md
+++ b/docs/changelog.md
@@ -6,6 +6,8 @@ Requires libvips v8.3.3
 
 #### v0.16.1 - TBD
 
+* C++11 ABI version is now auto-detected, remove sharp-cxx11 installation flag.
+
 * Ensure convolution kernel scale is clamped to a minimum value of 1.
   [#561](https://github.com/lovell/sharp/issues/561)
   [@abagshaw](https://github.com/abagshaw)
diff --git a/docs/install.md b/docs/install.md
index 1b1f3002..7b7947fc 100644
--- a/docs/install.md
+++ b/docs/install.md
@@ -22,24 +22,15 @@ Most recent Linux-based operating systems with glibc running on x64 and ARMv6+ C
 * Debian 7, 8
 * Ubuntu 12.04, 14.04, 16.04
 * Centos 7
-* Fedora 22, 23
+* Fedora 23, 24
 * openSUSE 13.2
 * Archlinux
 * Raspbian Jessie
-* Amazon Linux 2016.03
+* Amazon Linux 2016.03, 2016.09
 
-To use your own version of libvips instead of the provided binaries, make sure it is
-at least the version listed under `config.libvips` in the `package.json` file and
-that it can be located using `pkg-config --modversion vips-cpp`.
-
-There are [changes in the C++11 ABI](https://gcc.gnu.org/onlinedocs/libstdc++/manual/using_dual_abi.html)
-when using v5.1+ of the `g++` compiler.
-If you have installed `libvips-dev` via package manager on an OS such as Debian testing/unstable,
-you can pass the required value of the `_GLIBCXX_USE_CXX11_ABI` macro using the `--sharp-cxx11` flag.
-
-```sh
-npm install --sharp-cxx11=1
-```
+To use a globally-installed version of libvips instead of the provided binaries,
+make sure it is at least the version listed under `config.libvips` in the `package.json` file
+and that it can be located using `pkg-config --modversion vips-cpp`.
 
 If you are using non-stadard paths (anything other than `/usr` or `/usr/local`),
 you might need to set `PKG_CONFIG_PATH` during `npm install`