BLD: check for CBLAS header in "unoptimized" blas

Allows building against system installed blas library that might be
optimized.

1 files changed, 25 insertions, 1 deletions

diff --git a/numpy/distutils/system_info.py b/numpy/distutils/system_info.py
index 75c2c0ea5..ddb1513c4 100644
--- a/numpy/distutils/system_info.py
+++ b/numpy/distutils/system_info.py
@@ -1560,9 +1560,33 @@ class blas_info(system_info):
         info = self.check_libs(lib_dirs, blas_libs, [])
         if info is None:
             return
-        info['language'] = 'f77'  # XXX: is it generally true?
+        if self.has_cblas():
+            info['language'] = 'c'
+            info['define_macros'] = [('HAVE_CBLAS', None)]
+        else:
+            info['language'] = 'f77'  # XXX: is it generally true?
         self.set_info(**info)
 
+    def has_cblas(self):
+        # primitive cblas check by looking for the header
+        res = False
+        c = distutils.ccompiler.new_compiler()
+        tmpdir = tempfile.mkdtemp()
+        s = """#include <cblas.h>"""
+        src = os.path.join(tmpdir, 'source.c')
+        try:
+            with open(src, 'wt') as f:
+                f.write(s)
+            try:
+                c.compile([src], output_dir=tmpdir,
+                          include_dirs=self.get_include_dirs())
+                res = True
+            except distutils.ccompiler.CompileError:
+                res = False
+        finally:
+            shutil.rmtree(tmpdir)
+        return res
+
 
 class openblas_info(blas_info):
     section = 'openblas'