Merge pull request xtensor-stack#197 from PerretB/explicit_long_long_allocator_instanciation

JohanMabille · web-flow · commit 9e577981c0db · 2019-05-09T22:04:42.000+02:00
Explicit long long allocator instantiation
diff --git a/docs/source/compilers.rst b/docs/source/compilers.rst
@@ -0,0 +1,20 @@
+.. Copyright (c) 2016, Johan Mabille, Sylvain Corlay and Wolf Vollprecht
+
+   Distributed under the terms of the BSD 3-Clause License.
+
+   The full license is in the file LICENSE, distributed with this software.
+
+Compiler workarounds
+====================
+
+This page tracks the workarounds for the various compiler issues that we
+encountered in the development. This is mostly of interest for developers
+interested in contributing to xtensor-python.
+
+GCC and ``std::allocator<long long>``
+-------------------------------------
+
+GCC sometimes fails to automatically instantiate the ``std::allocator``
+class template for the types ``long long`` and ``unsigned long long``.
+Those allocators are thus explicitly instantiated in the dummy function
+``void long_long_allocator()`` in the file ``py_container.hpp``.
diff --git a/docs/source/index.rst b/docs/source/index.rst
@@ -73,6 +73,7 @@ This software is licensed under the BSD-3-Clause license. See the LICENSE file f
 .. toctree::
    :caption: DEVELOPER ZONE
 
+   compilers
    releasing
 
 .. _NumPy: http://www.numpy.org
diff --git a/include/xtensor-python/pycontainer.hpp b/include/xtensor-python/pycontainer.hpp
@@ -455,6 +455,18 @@ namespace xt
         }
 #endif
     }
+
+#if defined(__GNUC__) && !defined(__clang__)
+    namespace workaround
+    {
+        // Fixes "undefined symbol" issues
+        inline void long_long_allocator()
+        {
+            std::allocator<long long> a;
+            std::allocator<unsigned long long> b;
+        }
+    }
+#endif
 }
 
 #endif

Original file line number	Diff line number	Diff line change
`@@ -455,6 +455,18 @@ namespace xt`
`455`	`455`	`}`
`456`	`456`	`#endif`
`457`	`457`	`}`
	`458`	`+`
	`459`	`+#if defined(__GNUC__) && !defined(__clang__)`
	`460`	`+ namespace workaround`
	`461`	`+ {`
	`462`	`+ // Fixes "undefined symbol" issues`
	`463`	`+ inline void long_long_allocator()`
	`464`	`+ {`
	`465`	`+ std::allocator<long long> a;`
	`466`	`+ std::allocator<unsigned long long> b;`
	`467`	`+ }`
	`468`	`+ }`
	`469`	`+#endif`
`458`	`470`	`}`
`459`	`471`
`460`	`472`	`#endif`