From: Lang Hames <lhames@gmail.com>
Date: Tue, 6 Oct 2015 22:55:05 +0000 (+0000)
Subject: [Orc] Teach the CompileOnDemand layer to clone aliases.
X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=commitdiff_plain;h=3ce6a234699f2cb088b9d666c6e5021af7e85d54

[Orc] Teach the CompileOnDemand layer to clone aliases.

This allows modules containing aliases to be lazily jit'd. Previously these
failed with missing symbol errors because the aliases weren't cloned from the
original module.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@249481 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/include/llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h b/include/llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h
index 9694b80d192..714ca2374dc 100644
--- a/include/llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h
+++ b/include/llvm/ExecutionEngine/Orc/CompileOnDemandLayer.h
@@ -217,6 +217,10 @@ private:
       if (!GV.isDeclaration())
         cloneGlobalVariableDecl(*GVsAndStubsM, GV, &VMap);
 
+    // And the aliases.
+    for (auto &Alias : SrcM->aliases())
+      cloneGlobalAlias(*GVsAndStubsM, Alias, VMap, &GDMat);
+
     // Then clone the initializers.
     for (auto &GV : SrcM->globals())
       if (!GV.isDeclaration())
diff --git a/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h b/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h
index 4b7fc5e84b9..e5cd0d2559c 100644
--- a/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h
+++ b/include/llvm/ExecutionEngine/Orc/IndirectionUtils.h
@@ -289,6 +289,10 @@ void moveGlobalVariableInitializer(GlobalVariable &OrigGV,
                                    ValueMaterializer *Materializer = nullptr,
                                    GlobalVariable *NewGV = nullptr);
 
+GlobalAlias* cloneGlobalAlias(Module &Dst, const GlobalAlias &OrigA,
+                              ValueToValueMapTy &VMap,
+                              ValueMaterializer *Materializer = nullptr);
+
 } // End namespace orc.
 } // End namespace llvm.
 
diff --git a/lib/ExecutionEngine/Orc/IndirectionUtils.cpp b/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
index b439810ed33..ddd1921657b 100644
--- a/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
+++ b/lib/ExecutionEngine/Orc/IndirectionUtils.cpp
@@ -177,5 +177,19 @@ void moveGlobalVariableInitializer(GlobalVariable &OrigGV,
                                  nullptr, Materializer));
 }
 
+GlobalAlias* cloneGlobalAlias(Module &Dst, const GlobalAlias &OrigA,
+                              ValueToValueMapTy &VMap,
+                              ValueMaterializer *Materializer) {
+  assert(OrigA.getAliasee() && "Original alias doesn't have an aliasee?");
+  auto *NewA = GlobalAlias::create(OrigA.getValueType(),
+                                   OrigA.getType()->getPointerAddressSpace(),
+                                   OrigA.getLinkage(), OrigA.getName(), &Dst);
+  NewA->copyAttributesFrom(&OrigA);
+  VMap[&OrigA] = NewA;
+  NewA->setAliasee(cast<Constant>(MapValue(OrigA.getAliasee(), VMap, RF_None,
+                                           nullptr, Materializer)));
+  return NewA;
+}
+
 } // End namespace orc.
 } // End namespace llvm.
diff --git a/test/ExecutionEngine/OrcLazy/global_aliases.ll b/test/ExecutionEngine/OrcLazy/global_aliases.ll
new file mode 100644
index 00000000000..61fde4bebf8
--- /dev/null
+++ b/test/ExecutionEngine/OrcLazy/global_aliases.ll
@@ -0,0 +1,21 @@
+; RUN: lli -jit-kind=orc-lazy %s
+;
+; Test handling of global aliases for function and variables.
+
+@x = global i32 42, align 4
+@y = alias i32, i32* @x
+
+define i32 @foo() {
+entry:
+  %0 = load i32, i32* @y, align 4
+  ret i32 %0
+}
+
+@bar = alias i32(), i32()* @foo
+
+define i32 @main(i32 %argc, i8** %argv) {
+entry:
+  %0 = call i32() @bar()
+  %1 = sub i32 %0, 42
+  ret i32 %1
+}