Add logic to detect and discriminate C++-11.

.travis.yml

@@ -11,24 +11,30 @@ dist: trusty
 
 language: cpp
 
-env:
-  matrix:
-  - PYTHON=python CCFLAGS=-std=c++98
-  - PYTHON=python CCFLAGS=-std=c++11
-  - PYTHON=python3 CCFLAGS=-std=c++98
-  - PYTHON=python3 CCFLAGS=-std=c++11
-  - PYTHON=python DOC=1
+matrix:
+  include:
+  - compiler: gcc
+    env: CXX=g++ PYTHON=python CXXFLAGS=-std=c++98
+  - compiler: gcc
+    env: CXX=g++ PYTHON=python CXXFLAGS=-std=c++11
+  - compiler: gcc
+    env: CXX=g++ PYTHON=python3 CXXFLAGS=-std=c++98
+  - compiler: gcc
+    env: CXX=g++ PYTHON=python3 CXXFLAGS=-std=c++11
+  - compiler: clang
+    env: CXX=clang++ PYTHON=python3 CXXFLAGS=-std=c++98
+  - compiler: clang
+    env: CXX=clang++ PYTHON=python3 CXXFLAGS=-std=c++11
+  - env: PYTHON=python DOC=1
   global:
   - secure: mqoxglbUN/At/r8O7nLVccGldnB1jvhLHNyYjfCXrdOD0GNX+TY2TS1+kIEv9Deg/P6X/QvrBa/ZzbDNryn3mDXBfOSy400ebSIUHHP3HtGHJShOGDyXedY3hZ/dqmxdV3p9hIxv4lcx1HPyC96s4wpiR0S9F1JBzD6scIabezM=
 
-compiler:
-- gcc
-
 addons:
   apt:
     sources:
     - ubuntu-toolchain-r-test
     packages:
+    - scons
     - gcc-4.8
     - g++-4.8
     - clang
@@ -46,11 +52,14 @@ before_install:
 - sudo pip install future
 
 install:
-- if [ "$CXX" = "g++" ]; then export CXX="g++-4.8" CC="gcc-4.8"; fi
+
+before_script:
+- scons --version
 
 script:
 - scons config --python=$PYTHON
 - if [ "$DOC" ]; then scons doc; else scons && scons test; fi
 
 after_success:
-- if [ "$DOC" -a "$TRAVIS_PULL_REQUEST" = "false" ]; then .ci/upload_docs.sh; fi
+# Upload docs only when building upstream.
+- if [ "$DOC" -a "$TRAVIS_REPO_SLUG" = "boostorg/python" -a "$TRAVIS_PULL_REQUEST" = "false" ]; then .ci/upload_docs.sh; fi

SConstruct

@@ -12,7 +12,8 @@ import config
 import config.ui
 import platform
 import os
-
+import subprocess
+import re
 
 #
 # We try to mimic the typical autotools-workflow.
@@ -35,10 +36,23 @@ if not os.path.exists('bin.SCons/'):
 vars = Variables('bin.SCons/config.py', ARGUMENTS)
 config.add_options(vars)
 arch = ARGUMENTS.get('arch', platform.machine())
+env_vars = {}
+if 'CXX' in os.environ: env_vars['CXX'] = os.environ['CXX']
+if 'CXXFLAGS' in os.environ: env_vars['CXXFLAGS'] = os.environ['CXXFLAGS'].split()
 env = Environment(toolpath=['config/tools'],
                   tools=['default', 'libs', 'tests', 'doc'],
                   variables=vars,
-                  TARGET_ARCH=arch)
+                  TARGET_ARCH=arch,
+                  **env_vars)
+if 'gcc' in env['TOOLS']:
+    # Earlier SCons versions (~ 2.3.0) can't handle CXX=clang++.
+    version = subprocess.check_output([env['CXX'], '--version'])
+    match = re.search(r'[0-9]+(\.[0-9]+)+', version)
+    if match:
+        version = match.group(0)
+    else:
+        version = 'unknown'
+    env['CXXVERSION'] = version
 
 Help(config.ui.help(vars, env) + """
 Variables are saved in bin.SCons/config.py and persist between scons invocations.

config/__init__.py

@@ -11,6 +11,7 @@ from SCons.Script import AddOption
 from collections import OrderedDict
 import platform
 from . import ui
+from . import cxx
 from . import python
 from . import boost
 
@@ -19,14 +20,17 @@ def add_options(vars):
     python.add_options(vars)
     boost.add_options(vars)
 
+    vars.Add('CXX')
     vars.Add('CPPPATH', converter=lambda v:v.split())
     vars.Add('CCFLAGS', converter=lambda v:v.split())
+    vars.Add('CXXFLAGS', converter=lambda v:v.split())
     vars.Add('LIBPATH', converter=lambda v:v.split())
     vars.Add('LIBS', converter=lambda v:v.split())
     vars.Add('PYTHON')
     vars.Add('PYTHONLIBS')
     vars.Add('prefix')
-    vars.Add('boostbook_prefix')
+    vars.Add('boostbook_prefix',
+    vars.Add('CXX11'))
 
     ui.add_variable(vars, ("arch", "target architeture", platform.machine()))
     ui.add_variable(vars, ("toolchain", "toolchain to use", 'gcc'))
@@ -40,6 +44,7 @@ def add_options(vars):
 
 def get_checks():
   checks = OrderedDict()
+  checks['cxx'] = cxx.check
   checks['python'] = python.check
   checks['boost'] = boost.check
   return checks
@@ -64,7 +69,10 @@ def boost_suffix(env):
 
     if env["layout"] == "versioned":
         if "gcc" in env["TOOLS"]:
-            suffix += "-gcc" + "".join(env["CCVERSION"].split(".")[0:2])
+            if env['CXX'] in ('clang', 'clang++'):
+                suffix += "-clang" + "".join(env["CXXVERSION"].split(".")[0:2])
+            else: # assume g++
+                suffix += "-gcc" + "".join(env["CXXVERSION"].split(".")[0:2])
     if env["THREADING"] == "multi":
         suffix += "-mt"
     if env["DEBUG"]:
@@ -80,10 +88,15 @@ def prepare_build_dir(env):
     vars = {}
     env["boost_suffix"] = boost_suffix
     build_dir="bin.SCons"
+    # FIXME: Support 'toolchain' variable properly.
+    #        For now, we simply check whether $CXX refers to clang or gcc.
     if "gcc" in env["TOOLS"]:
-        build_dir+="/gcc-%s"%env["CCVERSION"]
-        vars['CXXFLAGS'] = ['-ftemplate-depth-128', '-Wall']
-
+        if env['CXX'] in ('clang', 'clang++'):
+            build_dir+="/clang-%s"%env["CXXVERSION"]
+        else: # assume g++
+            build_dir+="/gcc-%s"%env["CXXVERSION"]
+        default_cxxflags = ['-ftemplate-depth-128', '-Wall', '-g', '-O2']
+        vars['CXXFLAGS'] = env.get('CXXFLAGS', default_cxxflags)
     elif "msvc" in env["TOOLS"]:
         build_dir+="/msvc-%s"%env["MSVS_VERSION"]
     vars['BOOST_BUILD_DIR'] = build_dir

config/cxx.py

@@ -0,0 +1,30 @@
+#
+# Copyright (c) 2016 Stefan Seefeld
+# All rights reserved.
+#
+# Distributed under the Boost Software License, Version 1.0.
+# (See accompanying file LICENSE_1_0.txt or copy at
+# http://www.boost.org/LICENSE_1_0.txt)
+
+from . import ui
+import os
+
+def add_options(vars):
+
+    pass
+
+def check(context):
+
+    source = r"""#if __cplusplus < 201103L
+#error no C++11
+#endif"""
+
+    context.Message('Checking for C++11 support...')
+
+    if not context.TryCompile(source, '.cpp'):
+        context.env['CXX11'] = False
+        context.Result(0)
+    else:
+        context.env['CXX11'] = True
+        context.Result(1)
+    return True