From d491d91dd27849eac3bd070f2069fe25fa98e398 Mon Sep 17 00:00:00 2001
From: Siu Kwan Lam <michael.lam.sk@gmail.com>
Date: Thu, 29 Nov 2012 12:36:54 -0600
Subject: [PATCH] Add TBAA Builder

---
 llvm/tbaa.py | 51 +++++++++++++++++++++++++++++++++++++++++++++++++++
 test/tbaa.py | 34 ++++++++++++++++++++++++++++++++++
 2 files changed, 85 insertions(+)
 create mode 100644 llvm/tbaa.py
 create mode 100644 test/tbaa.py

diff --git a/llvm/tbaa.py b/llvm/tbaa.py
new file mode 100644
index 0000000..d8e0074
--- /dev/null
+++ b/llvm/tbaa.py
@@ -0,0 +1,51 @@
+from llvm.core import *
+
+class TBAABuilder(object):
+    '''Simplify creation of TBAA metadata.
+    
+    Each TBAABuidler object operates on a module.  
+    User can create multiple TBAABuilder on a module
+    '''
+    
+    def __init__(self, module, rootid):
+        '''
+        module --- the module to use.
+        root --- string name to identify the TBAA root.
+        '''
+        self.__module = module
+        self.__rootid = rootid
+        self.__rootmd = self.__new_md(rootid)
+
+    @classmethod
+    def new(cls, module, rootid):
+        return cls(module, rootid)
+
+    def get_node(self, name, parent=None, const=False):
+        '''Returns a MetaData object representing a TBAA node.
+
+        Use loadstore_instruction.set_metadata('tbaa', node) to 
+        bind a type to a memory.
+        '''
+        parent = parent or self.root
+        const = Constant.int(Type.int(), int(bool(const)))
+        return self.__new_md(name, parent, const)
+
+    @property
+    def module(self):
+        return self.__module
+
+    @property
+    def root(self):
+        return self.__rootmd
+
+    @property
+    def root_name(self):
+        return self.__rootid
+
+    def __new_md(self, *args):
+        contents = list(args)
+        for i, v in enumerate(contents):
+            if isinstance(v, str):
+                contents[i] = MetaDataString.get(self.module, v)
+        return MetaData.get(self.module, contents)
+
diff --git a/test/tbaa.py b/test/tbaa.py
new file mode 100644
index 0000000..d775a53
--- /dev/null
+++ b/test/tbaa.py
@@ -0,0 +1,34 @@
+from llvm.core import *
+from llvm.tbaa import *
+import unittest
+
+class TestTBAABuilder(unittest.TestCase):
+    def test_tbaa_builder(self):
+        mod = Module.new('test_tbaa_builder')
+        fty = Type.function(Type.void(), [Type.pointer(Type.float())])
+        foo = mod.add_function(fty, 'foo')
+        bb = foo.append_basic_block('entry')
+        bldr = Builder.new(bb)
+
+        tbaa = TBAABuilder.new(mod, "tbaa.root")
+        float = tbaa.get_node('float', const=False)
+        const_float = tbaa.get_node('const float', float, const=True)
+
+
+        tbaa = TBAABuilder.new(mod, "tbaa.root")
+        old_const_float = const_float
+        del const_float
+
+        const_float = tbaa.get_node('const float', float, const=True)
+
+        self.assertIs(old_const_float, const_float)
+
+        ptr = bldr.load(foo.args[0])
+        ptr.set_metadata('tbaa', const_float)
+
+
+        bldr.ret_void()
+        print mod
+
+if __name__ == '__main__':
+    unittest.main()