Merge pull request #11009 from jckarter/unused-try-exit-block-4.0

[4.0] SILGen: Remove unused catch block for a try? expr using SGF.eraseBasicBlock().
apple · Jul 18, 2017 · dd684ea · dd684ea
2 parents c184647 + 31af652
commit dd684ea
Show file tree

Hide file tree

Showing 2 changed files with 10 additions and 1 deletion.
diff --git a/lib/SILGen/SILGenExpr.cpp b/lib/SILGen/SILGenExpr.cpp
@@ -1212,7 +1212,7 @@ RValue RValueEmitter::visitOptionalTryExpr(OptionalTryExpr *E, SGFContext C) {
   // If it turns out there are no uses of the catch block, just drop it.
   if (catchBB->pred_empty()) {
     // Remove the dead failureBB.
-    catchBB->eraseFromParent();
+    SGF.eraseBasicBlock(catchBB);
 
     // The value we provide is the one we've already got.
     if (!isByAddress)

diff --git a/test/SILGen/errors.swift b/test/SILGen/errors.swift
@@ -778,6 +778,15 @@ func testOptionalTry() {
   _ = try? make_a_cat()
 }
 
+func sudo_make_a_cat() {}
+
+// CHECK-LABEL: sil hidden @{{.*}}testOptionalTryThatNeverThrows
+func testOptionalTryThatNeverThrows() {
+  guard let _ = try? sudo_make_a_cat() else { // expected-warning{{no calls to throwing}}
+    return
+  }
+}
+
 // CHECK-LABEL: sil hidden @_T06errors18testOptionalTryVaryyF
 // CHECK-NEXT: bb0:
 // CHECK-NEXT: [[BOX:%.+]] = alloc_box ${ var Optional<Cat> }