[CodeExtractor] Store outputs at the first valid insertion point

When CodeExtractor outlines values which are used by the original
function, it must store those values in some in-out parameter. This
store instruction must not be inserted in between a PHI and an EH pad
instruction, as that results in invalid IR.

This fixes the following verifier failure seen while outlining within
ObjC methods with live exit values:

  The unwind destination does not have an exception handling instruction!
    %call35 = invoke i8* bitcast (i8* (i8*, i8*, ...)* @objc_msgSend to i8* (i8*, i8*)*)(i8* %exn.adjusted, i8* %1)
            to label %invoke.cont34 unwind label %lpad33, !dbg !4183
  The unwind destination does not have an exception handling instruction!
    invoke void @objc_exception_throw(i8* %call35) #12
            to label %invoke.cont36 unwind label %lpad33, !dbg !4184
  LandingPadInst not the first non-PHI instruction in the block.
    %3 = landingpad { i8*, i32 }
            catch i8* null, !dbg !1411

rdar://46540815

llvm-svn: 348562

1 files changed, 68 insertions, 0 deletions

diff --git a/llvm/unittests/Transforms/Utils/CodeExtractorTest.cpp b/llvm/unittests/Transforms/Utils/CodeExtractorTest.cpp
index 42448fd8fd0..7e3512f56f3 100644
--- a/llvm/unittests/Transforms/Utils/CodeExtractorTest.cpp
+++ b/llvm/unittests/Transforms/Utils/CodeExtractorTest.cpp
@@ -127,4 +127,72 @@ TEST(CodeExtractor, ExitPHIOnePredFromRegion) {
   EXPECT_FALSE(verifyFunction(*Outlined));
   EXPECT_FALSE(verifyFunction(*Func));
 }
+
+TEST(CodeExtractor, StoreOutputInvokeResultAfterEHPad) {
+  LLVMContext Ctx;
+  SMDiagnostic Err;
+  std::unique_ptr<Module> M(parseAssemblyString(R"invalid(
+    declare i8 @hoge()
+
+    define i32 @foo() personality i8* null {
+      entry:
+        %call = invoke i8 @hoge()
+                to label %invoke.cont unwind label %lpad
+
+      invoke.cont:                                      ; preds = %entry
+        unreachable
+
+      lpad:                                             ; preds = %entry
+        %0 = landingpad { i8*, i32 }
+                catch i8* null
+        br i1 undef, label %catch, label %finally.catchall
+
+      catch:                                            ; preds = %lpad
+        %call2 = invoke i8 @hoge()
+                to label %invoke.cont2 unwind label %lpad2
+
+      invoke.cont2:                                    ; preds = %catch
+        %call3 = invoke i8 @hoge()
+                to label %invoke.cont3 unwind label %lpad2
+
+      invoke.cont3:                                    ; preds = %invoke.cont2
+        unreachable
+
+      lpad2:                                           ; preds = %invoke.cont2, %catch
+        %ex.1 = phi i8* [ undef, %invoke.cont2 ], [ null, %catch ]
+        %1 = landingpad { i8*, i32 }
+                catch i8* null
+        br label %finally.catchall
+
+      finally.catchall:                                 ; preds = %lpad33, %lpad
+        %ex.2 = phi i8* [ %ex.1, %lpad2 ], [ null, %lpad ]
+        unreachable
+    }
+  )invalid", Err, Ctx));
+
+	if (!M) {
+    Err.print("unit", errs());
+    exit(1);
+  }
+
+  Function *Func = M->getFunction("foo");
+  EXPECT_FALSE(verifyFunction(*Func, &errs()));
+
+  SmallVector<BasicBlock *, 2> ExtractedBlocks{
+    getBlockByName(Func, "catch"),
+    getBlockByName(Func, "invoke.cont2"),
+    getBlockByName(Func, "invoke.cont3"),
+    getBlockByName(Func, "lpad2")
+  };
+
+  DominatorTree DT(*Func);
+  CodeExtractor CE(ExtractedBlocks, &DT);
+  EXPECT_TRUE(CE.isEligible());
+
+  Function *Outlined = CE.extractCodeRegion();
+  EXPECT_TRUE(Outlined);
+  EXPECT_FALSE(verifyFunction(*Outlined, &errs()));
+  EXPECT_FALSE(verifyFunction(*Func, &errs()));
+}
+
 } // end anonymous namespace