build-aux: rewrite mock inline checker in Python

As part of a goal to eliminate Perl from libvirt build tools,
rewrite the mock-noinline.pl tool in Python.

This was a straight conversion, manually going line-by-line to
change the syntax from Perl to Python. Thus the overall structure
of the file and approach is the same.

Tested-by: Cole Robinson <crobinso@redhat.com>
Reviewed-by: Ján Tomko <jtomko@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>

scripts/mock-noinline.py

@@ -0,0 +1,84 @@
+#!/usr/bin/env python
+#
+# Copyright (C) 2017-2019 Red Hat, Inc.
+#
+# This library is free software; you can redistribute it and/or
+# modify it under the terms of the GNU Lesser General Public
+# License as published by the Free Software Foundation; either
+# version 2.1 of the License, or (at your option) any later version.
+#
+# This library is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+# Lesser General Public License for more details.
+#
+# You should have received a copy of the GNU Lesser General Public
+# License along with this library.  If not, see
+# <http://www.gnu.org/licenses/>.
+
+from __future__ import print_function
+
+import re
+import sys
+
+noninlined = {}
+mocked = {}
+
+# Functions in public header don't get the noinline annotation
+# so whitelist them here
+noninlined["virEventAddTimeout"] = True
+# This one confuses the script as its defined in the mock file
+# but is actually just a local helper
+noninlined["virMockStatRedirect"] = True
+
+
+def scan_annotations(filename):
+    with open(filename, "r") as fh:
+        func = None
+        for line in fh:
+            m = re.search(r'''^\s*(\w+)\(''', line)
+            if m is None:
+                m = re.search(r'''^(?:\w+\*?\s+)+(?:\*\s*)?(\w+)\(''', line)
+            if m is not None:
+                name = m.group(1)
+                if "ATTRIBUTE" not in name and "G_GNUC_" not in name:
+                    func = name
+            elif line.isspace():
+                func = None
+
+            if "G_GNUC_NO_INLINE" in line:
+                if func is not None:
+                    noninlined[func] = True
+
+
+def scan_overrides(filename):
+    with open(filename, "r") as fh:
+        lineno = 0
+        for line in fh:
+            lineno = lineno + 1
+
+            m = re.search(r'''^(\w+)\(''', line)
+            if m is None:
+                m = re.search(r'''^\w+\s*(?:\*\s*)?(\w+)\(''', line)
+            if m is not None:
+                name = m.group(1)
+                if name.startswith("vir"):
+                    mocked[name] = "%s:%d" % (filename, lineno)
+
+
+for filename in sys.argv[1:]:
+    if filename.endswith(".h"):
+        scan_annotations(filename)
+    elif filename.endswith("mock.c"):
+        scan_overrides(filename)
+
+warned = False
+for func in mocked.keys():
+    if func not in noninlined:
+        warned = True
+        print("%s is mocked at %s but missing noinline annotation" %
+              (func, mocked[func]), file=sys.stderr)
+
+if warned:
+    sys.exit(1)
+sys.exit(0)