Add a flag for disabling LTO.

QuLogic · QuLogic · commit 9782f7cd959f · 2020-06-12T19:36:09.000-04:00
For developers, it may be useful to disable it to improve build time
when repeatedly re-building.
diff --git a/setup.cfg.template b/setup.cfg.template
@@ -3,6 +3,9 @@
 [egg_info]
 
 [libs]
+# By default, Matplotlib builds with LTO, which may be slow if you re-compile
+# often, and don't need the space saving/speedup.
+#enable_lto = True
 # By default, Matplotlib downloads and builds its own copy of FreeType, and
 # builds its own copy of Qhull.  You may set the following to True to instead
 # link against a system FreeType/Qhull.
diff --git a/setup.py b/setup.py
@@ -103,6 +103,8 @@ def add_optimization_flags(self):
         """
 
         env = os.environ.copy()
+        if not setupext.config.getboolean('libs', 'enable_lto', fallback=True):
+            return env
         if sys.platform == 'win32':
             return env
 
