[move-only] Make sure we mark local function inout parameters with mark_must_check.

Originally, we were relying on capture info to determine if we needed to insert
this mark_must_check. This ignored that the way that we are handling
escaping/non-escaping is something that is approximated in the AST but actually
determined at SIL level. With that in mind, rather than relying on the capture
info here, just rely on us having an inout argument. The later SIL level
checking for inout escapes is able to handle mark_must_check and knows how to
turn off noncopyable errors in the closure where we detect the error to prevent
us from emitting further errors due to the mark_must_check here.

I discovered this while playing with the previous commit.

rdar://112555589

Author: gottesmm

lib/SILGen/SILGenProlog.cpp

@@ -1141,11 +1141,14 @@ static void emitCaptureArguments(SILGenFunction &SGF,
     fArg->setClosureCapture(true);
     arg = SILValue(fArg);
 
-    // If our capture is no escape and we have a noncopyable value, insert a
-    // consumable and assignable. If we have an escaping closure, we are going
-    // to emit an error later in SIL since it is illegal to capture an inout
-    // value in an escaping closure.
-    if (isInOut && ty.isPureMoveOnly() && capture.isNoEscape()) {
+    // If we have an inout noncopyable paramter, insert a consumable and
+    // assignable.
+    //
+    // NOTE: If we have an escaping closure, we are going to emit an error later
+    // in SIL since it is illegal to capture an inout value in an escaping
+    // closure. The later code knows how to handle that we have the
+    // mark_must_check here.
+    if (isInOut && ty.isPureMoveOnly()) {
       arg = SGF.B.createMarkMustCheckInst(
           Loc, arg, MarkMustCheckInst::CheckKind::ConsumableAndAssignable);
     }

test/SILGen/moveonly_escaping_closure.swift

@@ -614,7 +614,8 @@ func testConsumingEscapeClosureCaptureLet(_ f: consuming @escaping () -> ()) {
 // CHECK: } // end sil function '$s16moveonly_closure29testGlobalClosureCaptureInOutyyAA9SingleEltVzF'
 
 // CHECK-LABEL: sil private [ossa] @$s16moveonly_closure29testGlobalClosureCaptureInOutyyAA9SingleEltVzFyycfU_ : $@convention(thin) (@inout_aliasable SingleElt) -> () {
-// CHECK: bb0([[PROJECT:%.*]] : @closureCapture
+// CHECK: bb0([[ARG:%.*]] : @closureCapture
+// CHECK:   [[PROJECT:%.*]] = mark_must_check [consumable_and_assignable] [[ARG]]
 //
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK:   [[LOADED:%.*]] = load [copy] [[ACCESS]]
@@ -657,7 +658,8 @@ func testGlobalClosureCaptureInOut(_ x: inout SingleElt) {
 // CHECK: } // end sil function '$s16moveonly_closure31testLocalLetClosureCaptureInOutyyAA9SingleEltVzF'
 //
 // CHECK-LABEL: sil private [ossa] @$s16moveonly_closure31testLocalLetClosureCaptureInOutyyAA9SingleEltVzFyycfU_ : $@convention(thin) (@inout_aliasable SingleElt) -> () {
-// CHECK: bb0([[PROJECT:%.*]] : @closureCapture
+// CHECK: bb0([[ARG:%.*]] : @closureCapture
+// CHECK:   [[PROJECT:%.*]] = mark_must_check [consumable_and_assignable] [[ARG]]
 //
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK:   [[LOADED:%.*]] = load [copy] [[ACCESS]]
@@ -704,7 +706,8 @@ func testLocalLetClosureCaptureInOut(_ x: inout SingleElt) {
 // CHECK: } // end sil function '$s16moveonly_closure31testLocalVarClosureCaptureInOutyyAA9SingleEltVzF'
 //
 // CHECK-LABEL: sil private [ossa] @$s16moveonly_closure31testLocalVarClosureCaptureInOutyyAA9SingleEltVzFyycfU_ : $@convention(thin) (@inout_aliasable SingleElt) -> () {
-// CHECK: bb0([[PROJECT:%.*]] : @closureCapture
+// CHECK: bb0([[ARG:%.*]] : @closureCapture
+// CHECK:   [[PROJECT:%.*]] = mark_must_check [consumable_and_assignable] [[ARG]]
 //
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK:   [[LOADED:%.*]] = load [copy] [[ACCESS]]
@@ -752,7 +755,8 @@ func testLocalVarClosureCaptureInOut(_ x: inout SingleElt) {
 // CHECK: } // end sil function '$s16moveonly_closure026testInOutVarClosureCapturedE0yyyycz_AA9SingleEltVztF'
 //
 // CHECK-LABEL: sil private [ossa] @$s16moveonly_closure026testInOutVarClosureCapturedE0yyyycz_AA9SingleEltVztFyycfU_ : $@convention(thin) (@inout_aliasable SingleElt) -> () {
-// CHECK: bb0([[PROJECT:%.*]] : @closureCapture
+// CHECK: bb0([[ARG:%.*]] : @closureCapture
+// CHECK:   [[PROJECT:%.*]] = mark_must_check [consumable_and_assignable] [[ARG]]
 //
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK:   [[LOADED:%.*]] = load [copy] [[ACCESS]]
@@ -807,7 +811,8 @@ func testInOutVarClosureCaptureInOut(_ f: inout () -> (), _ x: inout SingleElt)
 // CHECK: } // end sil function '$s16moveonly_closure38testConsumingEscapeClosureCaptureInOutyyyycn_AA9SingleEltVztF'
 //
 // CHECK-LABEL: sil private [ossa] @$s16moveonly_closure38testConsumingEscapeClosureCaptureInOutyyyycn_AA9SingleEltVztFyycfU_ : $@convention(thin) (@inout_aliasable SingleElt) -> () {
-// CHECK: bb0([[PROJECT:%.*]] : @closureCapture
+// CHECK: bb0([[ARG:%.*]] : @closureCapture
+// CHECK:   [[PROJECT:%.*]] = mark_must_check [consumable_and_assignable] [[ARG]]
 //
 // CHECK:   [[ACCESS:%.*]] = begin_access [read] [unknown] [[PROJECT]]
 // CHECK:   [[LOADED:%.*]] = load [copy] [[ACCESS]]

test/SILOptimizer/moveonly_self_captures.swift

@@ -28,8 +28,17 @@ struct Test : ~Copyable {
         e = E()
         e2 = E2()
         func capture() {
-            let _ = self // expected-error {{copy of noncopyable typed value}}
-            let _ = self.e2 // expected-error {{copy of noncopyable typed value}}
+            let _ = self
+            let _ = self.e2 // expected-error {{cannot partially consume 'self'}}
+        }
+        capture()
+    }
+
+    init(y: ()) { // expected-error {{missing reinitialization of closure capture 'self' after consume}}
+        e = E()
+        e2 = E2()
+        func capture() {
+            let _ = self // expected-note {{consumed here}}
         }
         capture()
     }