CloneModule: Map global initializers after mapping the function

Global initializers may contain references to blockaddresses, which
won't have their VMap entries until after the function body is processed.
Fixes emitting broken initializers in llvm-reduce when functions using
blockaddress are deleted.

Author: arsenm

llvm/lib/Transforms/Utils/CloneModule.cpp

@@ -124,32 +124,6 @@ std::unique_ptr<Module> llvm::CloneModule(
     VMap[&I] = GI;
   }
 
-  // Now that all of the things that global variable initializer can refer to
-  // have been created, loop through and copy the global variable referrers
-  // over...  We also set the attributes on the global now.
-  //
-  for (const GlobalVariable &G : M.globals()) {
-    GlobalVariable *GV = cast<GlobalVariable>(VMap[&G]);
-
-    SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
-    G.getAllMetadata(MDs);
-    for (auto MD : MDs)
-      GV->addMetadata(MD.first, *MapMetadata(MD.second, VMap));
-
-    if (G.isDeclaration())
-      continue;
-
-    if (!ShouldCloneDefinition(&G)) {
-      // Skip after setting the correct linkage for an external reference.
-      GV->setLinkage(GlobalValue::ExternalLinkage);
-      continue;
-    }
-    if (G.hasInitializer())
-      GV->setInitializer(MapValue(G.getInitializer(), VMap));
-
-    copyComdat(GV, &G);
-  }
-
   // Similarly, copy over function bodies now...
   //
   for (const Function &I : M) {
@@ -212,6 +186,32 @@ std::unique_ptr<Module> llvm::CloneModule(
       NewNMD->addOperand(MapMetadata(N, VMap));
   }
 
+  // Now that all of the things that global variable initializer can refer to
+  // have been created, loop through and copy the global variable referrers
+  // over...  We also set the attributes on the global now.
+  //
+  for (const GlobalVariable &G : M.globals()) {
+    GlobalVariable *GV = cast<GlobalVariable>(VMap[&G]);
+
+    SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
+    G.getAllMetadata(MDs);
+    for (auto MD : MDs)
+      GV->addMetadata(MD.first, *MapMetadata(MD.second, VMap));
+
+    if (G.isDeclaration())
+      continue;
+
+    if (!ShouldCloneDefinition(&G)) {
+      // Skip after setting the correct linkage for an external reference.
+      GV->setLinkage(GlobalValue::ExternalLinkage);
+      continue;
+    }
+    if (G.hasInitializer())
+      GV->setInitializer(MapValue(G.getInitializer(), VMap));
+
+    copyComdat(GV, &G);
+  }
+
   return New;
 }
 

llvm/test/tools/llvm-reduce/reduce-functions-blockaddress-wrong-function.ll

@@ -1,14 +1,10 @@
 ; RUN: llvm-reduce --abort-on-invalid-reduction --delta-passes=functions --test FileCheck --test-arg --check-prefixes=INTERESTING --test-arg %s --test-arg --input-file %s -o %t
 ; RUN: FileCheck --check-prefixes=RESULT --input-file=%t %s
 
-; FIXME: This testcase exhibits nonsensical behavior. The first
-; function has blockaddress references. When the second function is
-; deleted, it causes the blockreferences from the first to be replaced
-; with inttoptr.
-
 ; INTERESTING: @blockaddr.table.other
 
-; RESULT: @blockaddr.table.other = private unnamed_addr constant [2 x ptr] [ptr inttoptr (i32 1 to ptr), ptr inttoptr (i32 1 to ptr)]
+; RESULT: @blockaddr.table.other = private unnamed_addr constant [2 x ptr] [ptr blockaddress(@bar, %L1), ptr blockaddress(@bar, %L2)]
+
 
 @blockaddr.table.other = private unnamed_addr constant [2 x ptr] [ptr blockaddress(@bar, %L1), ptr blockaddress(@bar, %L2)]