NFC: Cleanup ClosureScope/AccessEnforcementSelection/Tests.

Per Devin and John's review.

Author: atrick

include/swift/SILOptimizer/Analysis/ClosureScope.h

@@ -95,7 +95,7 @@ class ClosureScopeAnalysis : public SILAnalysis {
     IndexLookupFunc(const std::vector<SILFunction *> &indexedScopes)
         : indexedScopes(indexedScopes) {}
 
-    Optional<SILFunction *> operator()(int &idx) const {
+    Optional<SILFunction *> operator()(int idx) const {
       if (auto funcPtr = indexedScopes[idx]) {
         return funcPtr;
       }

lib/SILOptimizer/Mandatory/AccessEnforcementSelection.cpp

@@ -466,7 +466,7 @@ void SelectEnforcement::updateCapture(AddressCapture capture) {
 namespace {
 
 // Model the kind of access needed based on analyzing the access's source.
-// This is either determined to be static or dynamic, or requries further
+// This is either determined to be static or dynamic, or requires further
 // analysis of a boxed variable.
 struct SourceAccess {
   enum { StaticAccess, DynamicAccess, BoxAccess } kind;
@@ -534,8 +534,10 @@ void AccessEnforcementSelection::processFunction(SILFunction *F) {
 
       if (auto access = dyn_cast<BeginAccessInst>(inst))
         handleAccess(access);
+
       else if (auto access = dyn_cast<BeginUnpairedAccessInst>(inst))
         assert(access->getEnforcement() == SILAccessEnforcement::Dynamic);
+
       else if(auto pa = dyn_cast<PartialApplyInst>(inst))
         handlePartialApply(pa);
     }

test/SILOptimizer/access_enforcement_noescape.swift

@@ -6,11 +6,9 @@
 // (Some static/dynamic enforcement selection is done in SILGen, and some is
 // deferred. That may change over time but we want the outcome to be the same).
 //
-// Each FIXME line is a case that the current implementation misses.
-// The model is currently being refined, so this isn't set in stone.
-//
-// TODO: Ensure that each dynamic case is covered by
-// Interpreter/enforce_exclusive_access.swift.
+// These tests attempt to fully cover the possibilities of reads and
+// modifications to captures along with `inout` arguments on both the caller and
+// callee side.
 
 // Helper
 func doOne(_ f: () -> ()) {
@@ -30,10 +28,8 @@ func reentrantNoescape(fn: (() -> ()) -> ()) {
 }
 
 // Error: Cannot capture nonescaping closure.
-// Verification disabled because it suppresses all the other errors.
-// disabled-note@+1{{parameter 'fn' is implicitly non-escaping}}
+// This triggers an early diagnostics, so it's handled in inout_capture_disgnostics.swift.
 // func reentrantCapturedNoescape(fn: (() -> ()) -> ()) {
-//   disabled-error@+1{{closure use of non-escaping parameter 'fn' may allow it to escape}}
 //   let c = { fn {} }
 //   fn(c)
 // }
@@ -314,8 +310,8 @@ func inoutReadWriteInout(x: inout Int) {
 // CHECK: end_access [[ACCESS]] 
 // CHECK-LABEL: } // end sil function '_T027access_enforcement_noescape19inoutReadWriteInoutySiz1x_tFyycfU_'
 
-// Trap on boxed read + write inout.
-// FIXME: Passing a captured var as inout needs dynamic enforcement.
+// Traps on boxed read + write inout.
+// Covered by Interpreter/enforce_exclusive_access.swift.
 func readBoxWriteInout() {
   var x = 3
   let c = { _ = x }
@@ -339,12 +335,11 @@ func readBoxWriteInout() {
 // CHECK-LABEL: } // end sil function '_T027access_enforcement_noescape17readBoxWriteInoutyyFyycfU_'
 
 // Error: inout cannot be captured.
-// Verification disabled because is suppresses other errors.
-//func inoutReadBoxWriteInout(x: inout Int) {
-//  disabled-error@+1{{escaping closures can only capture inout parameters explicitly by value}}
-//  let c = { _ = x }
-//  doOneInout(c, &x)
-//}
+// This triggers an early diagnostics, so it's handled in inout_capture_disgnostics.swift.
+// func inoutReadBoxWriteInout(x: inout Int) {
+//   let c = { _ = x }
+//   doOneInout(c, &x)
+// }
 
 // Allow aliased noescape write + write.
 func writeWrite() {
@@ -401,9 +396,8 @@ func inoutWriteWrite(x: inout Int) {
 // CHECK: end_access [[ACCESS]] 
 // CHECK-LABEL: } // end sil function '_T027access_enforcement_noescape010inoutWriteE0ySiz1x_tFyycfU0_'
 
-// FIXME: Trap on aliased boxed write + noescape write.
-//
-// See the note above.
+// Traps on aliased boxed write + noescape write.
+// Covered by Interpreter/enforce_exclusive_access.swift.
 func writeWriteBox() {
   var x = 3
   let c = { x = 87 }
@@ -485,8 +479,8 @@ func inoutWriteWriteInout(x: inout Int) {
 // CHECK: end_access [[ACCESS]] 
 // CHECK-LABEL: } // end sil function '_T027access_enforcement_noescape010inoutWriteE5InoutySiz1x_tFyycfU_'
 
-// Trap on boxed write + write inout.
-// FIXME: Passing a captured var as inout needs dynamic enforcement.
+// Traps on boxed write + write inout.
+// Covered by Interpreter/enforce_exclusive_access.swift.
 func writeBoxWriteInout() {
   var x = 3
   let c = { x = 42 }
@@ -510,9 +504,8 @@ func writeBoxWriteInout() {
 // CHECK-LABEL: } // end sil function '_T027access_enforcement_noescape18writeBoxWriteInoutyyFyycfU_'
 
 // Error: Cannot capture inout
-// Verification disabled because it suppresses other errors.
+// This triggers an early diagnostics, so it's handled in inout_capture_disgnostics.swift.
 // func inoutWriteBoxWriteInout(x: inout Int) {
-//   disabled-error@+1{{escaping closures can only capture inout parameters explicitly by value}}
 //   let c = { x = 42 }
 //   doOneInout(c, &x)
 // }

test/SILOptimizer/inout_capture_diagnostics.swift

@@ -0,0 +1,28 @@
+// RUN: %target-swift-frontend -enforce-exclusivity=checked -Onone -emit-sil -swift-version 4 -verify -parse-as-library %s
+//
+// This is an adjunct to access_enforcement_noescape.swift to cover early static diagnostics.
+
+// Helper
+func doOneInout(_: ()->(), _: inout Int) {}
+
+// Error: Cannot capture nonescaping closure.
+// expected-note@+1{{parameter 'fn' is implicitly non-escaping}}
+func reentrantCapturedNoescape(fn: (() -> ()) -> ()) {
+  // expected-error@+1{{closure use of non-escaping parameter 'fn' may allow it to escape}}
+  let c = { fn {} }
+  fn(c)
+}
+
+// Error: inout cannot be captured.
+func inoutReadBoxWriteInout(x: inout Int) {
+  // expected-error@+1{{escaping closures can only capture inout parameters explicitly by value}}
+  let c = { _ = x }
+  doOneInout(c, &x)
+}
+
+// Error: Cannot capture inout
+func inoutWriteBoxWriteInout(x: inout Int) {
+  // expected-error@+1{{escaping closures can only capture inout parameters explicitly by value}}
+  let c = { x = 42 }
+  doOneInout(c, &x)
+}