getdeps: refine makefiles matcher for cmake reconfigure

Summary:
Only run cmake reconfigure for .cmake, .cmake.in and CMakeLists.txt
files changes.

Previously we would reconfigure for any change to a file with a path that
matched `cmake` which could result in false positives in cases where
you may be iterating on .py or .c files in shared cmake directories.

This also reclassifies non-cmake files under fbcode_builder/CMake as source
files so that we run cmake for those; previously they would cause a
reconfigure and build, now they just cause a build.

Reviewed By: xavierd

Differential Revision: D21364133

fbshipit-source-id: a1231f657d6c6056b269656c677d3449d8715cf6

build/fbcode_builder/getdeps/fetcher.py

@@ -35,6 +35,16 @@ except ImportError:
     from urllib.request import urlretrieve
 
 
+def file_name_is_cmake_file(file_name):
+    file_name = file_name.lower()
+    base = os.path.basename(file_name)
+    return (
+        base.endswith(".cmake")
+        or base.endswith(".cmake.in")
+        or base == "cmakelists.txt"
+    )
+
+
 class ChangeStatus(object):
     """ Indicates the nature of changes that happened while updating
     the source directory.  There are two broad uses:
@@ -71,11 +81,12 @@ class ChangeStatus(object):
         might need to rebuild, so we ignore it.
         Otherwise we record the file as a source file change. """
 
-        if "cmake" in file_name.lower():
+        file_name = file_name.lower()
+        if file_name_is_cmake_file(file_name):
             self.make_files += 1
-            return
-        if "/fbcode_builder/" in file_name:
-            return
+        elif "/fbcode_builder/cmake" in file_name:
+            self.source_files += 1
+        elif "/fbcode_builder/" not in file_name:
             self.source_files += 1
 
     def sources_changed(self):