Fix constructing a ThreadSafeModule from a Module in a different Ctx. (#474)

Author: maleadt

src/executionengine/ts_module.jl

@@ -37,8 +37,23 @@ end
 Base.unsafe_convert(::Type{API.LLVMOrcThreadSafeModuleRef}, mod::ThreadSafeModule) = mod.ref
 
 function ThreadSafeModule(mod::Module)
+    if context(mod) != context(ts_context())
+        # XXX: the C API doesn't expose the convenience method to create a TSModule from a
+        #      Module and a regular Context, only a method to create one from a Module
+        #      and a pre-existing TSContext, which isn't useful...
+        # TODO: expose the other convenience method?
+        # XXX: work around this by serializing/deserializing the module in the correct contex
+        bitcode = convert(MemoryBuffer, mod)
+        mod = context!(context(ts_context())) do
+            parse(Module, bitcode)
+        end
+    end
+    @assert context(mod) == context(ts_context())
+
     ref = API.LLVMOrcCreateNewThreadSafeModule(mod, ts_context())
-    ThreadSafeModule(ref)
+    tsm = ThreadSafeModule(ref)
+    mark_dispose(mod)
+    return tsm
 end
 
 function ThreadSafeModule(name::String)
@@ -48,9 +63,7 @@ function ThreadSafeModule(name::String)
     mod = context!(ctx) do
         Module(name)
     end
-    tsm = ThreadSafeModule(mod)
-    mark_dispose(mod)
-    return tsm
+    ThreadSafeModule(mod)
 end
 
 function dispose(mod::ThreadSafeModule)

test/orc_tests.jl

@@ -24,6 +24,22 @@ end
             true
         end
     end
+
+    @dispose ctx=Context() ts_ctx=ThreadSafeContext() begin
+        src_mod = LLVM.Module("SomeModule")
+        ts_mod = ThreadSafeModule(src_mod)
+        ts_mod() do copied_mod
+            # XXX: this is a very specific test to check the current implementation of the
+            #      ThreadSafeModule constructor, which currently copies the source module
+            #      from its context into the thread safe one. This is questionable; maybe
+            #      it should create a ThreadSafeModule in a ThreadSafeContext matching the
+            #      source context. However, that would result in a TSMod that doesn't match
+            #      the currently-active ts_context()...
+            @test context(copied_mod) != context(src_mod)
+            @test context(copied_mod) == context(ts_context())
+        end
+        dispose(ts_mod)
+    end
 end
 
 @testset "JITDylib" begin