BLD: add check for C99 restrict keyword

Define it as NPY_RESTRICT
Restrict indicates a memory block does not alias, gcc supports it in c89
with the __restrict__ keyword.

1 files changed, 17 insertions, 0 deletions

diff --git a/numpy/distutils/command/autodist.py b/numpy/distutils/command/autodist.py
index 5a9470b9b..af53c5104 100644
--- a/numpy/distutils/command/autodist.py
+++ b/numpy/distutils/command/autodist.py
@@ -28,6 +28,23 @@ static %(inline)s int static_func (void)
 
     return ''
 
+def check_restrict(cmd):
+    """Return the restrict identifier (may be empty)."""
+    cmd._check_compiler()
+    body = """
+static int static_func (char * %(restrict)s a)
+{
+    return 0;
+}
+"""
+
+    for kw in ['restrict', '__restrict__', '__restrict']:
+        st = cmd.try_compile(body % {'restrict': kw}, None, None)
+        if st:
+            return kw
+
+    return ''
+
 def check_compiler_gcc4(cmd):
     """Return True if the C compiler is GCC 4.x."""
     cmd._check_compiler()