diff --git a/srcxray.py b/srcxray.py
new file mode 100755
index 0000000..203d7b7
--- /dev/null
+++ b/srcxray.py
@@ -0,0 +1,172 @@
+#!/usr/bin/python3
+#
+# srcxray - source code X-ray
+#
+# Analyzes interconnections between functions and structures in source code.
+#
+# Uses cscope and git grep --show-function to
+# reveal references between identifiers.
+#
+# 2018 Constantine Shulyupin, const@MakeLinux.com
+#
+
+import inspect, random, os, sys, collections, subprocess, re
+
+black_list = ['aligned', '__attribute__', 'unlikely', 'typeof',
+        'u32',
+        'PVOP_CALLEE0', 'PVOP_VCALLEE0', 'PVOP_VCALLEE1', 'trace_hardirqs_off']
+
+level_limit = 7
+limit = 10000
+n = 0
+
+def print_limited(a):
+    print(a)
+    global n
+    n +=1
+    if n > limit:
+        print('Reached limit')
+        sys.exit(1)
+
+def log(*args, **kwargs):
+    print(inspect.stack()[1][3], str(*args).rstrip(), file=sys.stderr, **kwargs)
+    pass
+
+def popen(p):
+    return subprocess.Popen(p, shell=True, stdout=subprocess.PIPE, encoding="utf-8").stdout
+
+def extract_referer(line):
+    line = re.sub(r'__ro_after_init', '', line)
+    line = re.sub(r'FNAME\((\w+)\)', r'\1', line)
+    line = re.sub(r'.*TRACE_EVENT.*', '', line)
+    m = re.match(r'^[^\s]+=[^,]*\(\*(\b\w+)\)\s*[\(\[=][^;]*$', line)
+    if not m:
+        m = re.match(r'^[^\s]+=[^,]*(\b\w+)\s*[\(\[=][^;]*$', line)
+    if m:
+        return m.group(1)
+
+def extract_referer_test():
+    for a in {
+            "fs=good2()",
+            "f=static int fastop(struct x86_emulate_ctxt *ctxt, void (*fop)(struct fastop *))",
+            "f=int good(a, bad (*func)(arg))",
+            "f=EXPORT_SYMBOL_GPL(bad);",
+            "f=bad (*good)()",
+            "f=int FNAME(good)(a)",
+            "f=TRACE_EVENT(a)",
+            "f: a=in bad()" }:
+        print(a, '->', extract_referer(a))
+
+def func_referers_git_grep(name):
+    res = []
+    r = None
+    for line in popen(r'git grep --no-index --word-regexp --show-function "^\s.*\b%s"'%(name)):
+        # Filter out names in comment afer function, when comment start from ' *'
+        # To see the problem try "git grep -p and"
+        if re.match(r'.*: \* ', line):
+            r = None
+        if r and r != name and not r in black_list:
+            res.append(r)
+            r = None
+        r = extract_referer(line)
+    return res
+
+cscope_warned = False
+
+def func_referers_cscope(name):
+    global cscope_warned
+    if not os.path.isfile('cscope.out'):
+        if not cscope_warned:
+            print("Recommended: cscope -bkR", file=sys.stderr)
+            cscope_warned = True
+        return []
+    res = [ l.split()[1] for l in popen(r'cscope -d -L3 "%s"'%(name)) if not l in black_list]
+    if not res:
+        res = func_referers_git_grep(name)
+    return res
+
+def func_referers_all(name):
+    return set(func_referers_git_grep(name) + func_referers_cscope(name))
+
+def referers_tree(name, referer = None, printed = None, level = 0):
+    if not referer:
+        if os.path.isfile('cscope.out'):
+            referer = func_referers_cscope
+        else:
+            print("Using git grep only, recommended to run: cscope -bkR", file=sys.stderr)
+            referer = func_referers_git_grep
+    if isinstance(referer, str):
+        referer = eval(referer)
+    if not printed: printed = set()
+    if name in printed:
+        print_limited(level*'\t' + name + ' ^')
+        return
+    else:
+        print_limited(level*'\t' + name)
+    printed.add(name)
+    if level > level_limit - 2:
+        print_limited((level + 1)*'\t' + '...')
+        return ''
+    listed = set()
+    for a in referer(name):
+        if a in listed:
+            continue
+        referers_tree(a, referer, printed, level + 1)
+        listed.add(a)
+    return ''
+
+def call_tree(node, printed = None, level = 0):
+    if not os.path.isfile('cscope.out'):
+            print("Please run: cscope -bkR", file=sys.stderr)
+            return False
+    if printed == None: printed = set()
+    if node in printed:
+        limit= - 1
+        print_limited(level*'\t' + node + '^')
+        return
+    else:
+        print_limited(level*'\t' + node)
+    printed.add(node)
+    if level > level_limit - 2 :
+        print_limited((level + 1)*'\t' + '...')
+        return ''
+    local_printed = set()
+    for line in popen('cscope -d -L2 "%s"'%(node)):
+        I = line.split()[1];
+        if I in local_printed or I in black_list: continue;
+        local_printed.add(I)
+        try:
+            call_tree(line.split()[1], printed, level + 1);
+        except:
+            pass
+    return ''
+
+me = os.path.basename(sys.argv[0])
+
+def usage():
+    print(me, "referers_tree", "<identifier>")
+    print(me, "call_tree", "<identifier>")
+    print("Try this:")
+    print("cd linux/init")
+    print(me, "referers_tree nfs_root_data")
+    print(me, "call_tree start_kernel")
+    print(me, "Emergency termination: ^Z, kill %1")
+
+def main():
+    try:
+        ret = False
+        if len(sys.argv) == 1:
+            print('Run', me, 'usage')
+        else:
+            if  '(' in sys.argv[1]:
+                ret = eval(sys.argv[1])
+            else:
+                ret = eval(sys.argv[1] + '(' + ', '.join("'%s'"%(a) for a in sys.argv[2:]) + ')')
+        if type(ret) == type(False) and ret == False:
+            sys.exit(os.EX_CONFIG)
+        print(ret)
+    except KeyboardInterrupt:
+        warning("\nInterrupted")
+
+if __name__ == "__main__":
+    main()