Remove personality for declarations in CloneModule.

[eugenis]

Summary

Personality is copied as part of copyFunctionAttributes, but it is
invalid on a declaration. Remove the personality attribute it the
function body is not cloned.

Also add a verifier run over output modules in the llvm-split tool.

[pcc]

Instead of doing this, we should probably fix the module splitter to not set the personality attribute on a function declaration.

What does the verifier make of this?

[eugenis]

In D18486#383911, @pcc wrote:

Instead of doing this, we should probably fix the module splitter to not set the personality attribute on a function declaration.

Done.

What does the verifier make of this?

Verifier is not happy about this, but it is not being run. I've added a verifier pass to llvm-split, do you think it's a good idea?

[pcc]

LGTM

I've added a verifier pass to llvm-split, do you think it's a good idea?

Yes, the modules we get from the splitter should verify.

[eugenis]

r264667

lib/Transforms/Utils/CloneModule.cpp

std::unique_ptr<Module> llvm::CloneModule(
 
   // Similarly, copy over function bodies now...
   //
   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
     Function *F = cast<Function>(VMap[&*I]);
     if (!ShouldCloneDefinition(&*I)) {
       // Skip after setting the correct linkage for an external reference.
       F->setLinkage(GlobalValue::ExternalLinkage);
+      // Personality function is not valid on a declaration.
+      F->setPersonalityFn(nullptr);
       continue;
     }
     if (!I->isDeclaration()) {
       Function::arg_iterator DestI = F->arg_begin();
       for (Function::const_arg_iterator J = I->arg_begin(); J != I->arg_end();
            ++J) {
         DestI->setName(J->getName());
         VMap[&*J] = &*DestI++;

test/tools/llvm-split/personality.ll

+; Test that "personality" attributes are correctly updated when cloning modules.
+; RUN: llvm-split -o %t %s
+; RUN: llvm-dis -o - %t0 | FileCheck --check-prefix=CHECK0 %s
+; RUN: llvm-dis -o - %t1 | FileCheck --check-prefix=CHECK1 %s
+
+; CHECK0: define void @foo()
+; CHECK1: declare void @foo()
+define void @foo() {
+  ret void
+}
+
+; CHECK0: declare void @bar()
+; CHECK0-NOT: personality
+; CHECK1: define void @bar() personality i8* bitcast (void ()* @foo to i8*)
+define void @bar() personality i8* bitcast (void ()* @foo to i8*)
+{
+  ret void
+}

tools/llvm-split/llvm-split.cpp

 //===-- llvm-split: command line tool for testing module splitter ---------===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 //
 // This program can be used to test the llvm::SplitModule function.
 //
 //===----------------------------------------------------------------------===//
 
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/Bitcode/ReaderWriter.h"
 #include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Verifier.h"
 #include "llvm/IRReader/IRReader.h"
 #include "llvm/Support/CommandLine.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/SourceMgr.h"
 #include "llvm/Support/ToolOutputFile.h"
 #include "llvm/Support/raw_ostream.h"
 #include "llvm/Transforms/Utils/SplitModule.h"
 
SplitModule(std::move(M), NumOutputs, [&](std::unique_ptr<Module> MPart) {
     std::error_code EC;
     std::unique_ptr<tool_output_file> Out(new tool_output_file(
         OutputFilename + utostr(I++), EC, sys::fs::F_None));
     if (EC) {
       errs() << EC.message() << '\n';
       exit(1);
     }
 
+    verifyModule(*MPart);
     WriteBitcodeToFile(MPart.get(), Out->os());
 
     // Declare success.
     Out->keep();
   }, PreserveLocals);
 
   return 0;
 }