From c0e9dedc9048e7849b767c193542ef507d21f8c0 Mon Sep 17 00:00:00 2001
From: Siu Kwan Lam <michael.lam.sk@gmail.com>
Date: Wed, 31 Jul 2013 17:50:30 -0500
Subject: [PATCH] add binding to dynamiclibrary namespace for multimodule
 linking

---
 llvm/ee.py          | 14 ++++++++++++++
 llvm/test_llvmpy.py | 37 +++++++++++++++++++++++++++++++++++++
 2 files changed, 51 insertions(+)

diff --git a/llvm/ee.py b/llvm/ee.py
index 583201b..fe21ea2 100644
--- a/llvm/ee.py
+++ b/llvm/ee.py
@@ -195,6 +195,9 @@ class ExecutionEngine(llvm.Wrapper):
         ptr = self._ptr.runFunction(fn._ptr, list(map(lambda x: x._ptr, args)))
         return GenericValue(ptr)
 
+    def get_pointer_to_named_function(self, name, abort=True):
+        return self._ptr.getPointerToNamedFunction(name, abort)
+
     def get_pointer_to_function(self, fn):
         return self._ptr.getPointerToFunction(fn._ptr)
 
@@ -371,3 +374,14 @@ class TargetMachine(llvm.Wrapper):
     def feature_string(self):
         return self._ptr.getTargetFeatureString()
 
+
+
+#===----------------------------------------------------------------------===
+# Dynamic Library
+#===----------------------------------------------------------------------===
+
+def dylib_add_symbol(name, ptr):
+    api.llvm.sys.DynamicLibrary.AddSymbol(name, ptr)
+
+def dylib_address_of_symbol(name):
+    return api.llvm.sys.DynamicLibrary.SearchForAddressOfSymbol(name)
diff --git a/llvm/test_llvmpy.py b/llvm/test_llvmpy.py
index 8d38ed0..19c402c 100644
--- a/llvm/test_llvmpy.py
+++ b/llvm/test_llvmpy.py
@@ -1373,6 +1373,43 @@ class TestMCJIT(TestCase):
         callee = CFUNCTYPE(c_int, c_int, c_int)(ptr)
         self.assertEqual(321 + 123, callee(321, 123))
 
+    def test_multi_module_linking(self):
+        # generate external library module
+        m = Module.new('external-library-module')
+        fnty = Type.function(Type.int(), [Type.int(), Type.int()])
+        libfname = 'myadd'
+        func = m.add_function(fnty, libfname)
+        bb = func.append_basic_block('')
+        bldr = Builder.new(bb)
+        bldr.ret(bldr.add(*func.args))
+        func.verify()
+
+        # JIT the lib module and bind dynamic symbol
+        libengine = EngineBuilder.new(m).mcjit(True).create()
+        myadd_ptr = libengine.get_pointer_to_function(func)
+        le.dylib_add_symbol(libfname, myadd_ptr)
+
+        # reference external library
+        m = Module.new('user')
+        fnty = Type.function(Type.int(), [Type.int(), Type.int()])
+        func = m.add_function(fnty, 'foo')
+        bb = func.append_basic_block('')
+        bldr = Builder.new(bb)
+        extadd = m.get_or_insert_function(fnty, name=libfname)
+        bldr.ret(bldr.call(extadd, func.args))
+        func.verify()
+
+        # JIT the user module
+        engine = EngineBuilder.new(m).mcjit(True).create()
+        ptr = engine.get_pointer_to_function(func)
+        self.assertEqual(myadd_ptr,
+                         engine.get_pointer_to_named_function(libfname))
+
+        from ctypes import c_int, CFUNCTYPE
+        callee = CFUNCTYPE(c_int, c_int, c_int)(ptr)
+        self.assertEqual(321 + 123, callee(321, 123))
+
+
 if llvm.version >= (3, 3):
     # MCJIT broken in 3.2
     # The test will segfault in OSX?