[Sema] Support pattern binding decls with -require-explicit-availability

Author: xymus

lib/Sema/TypeCheckAvailability.cpp

@@ -2879,19 +2879,19 @@ static bool declNeedsExplicitAvailability(const Decl *decl) {
 }
 
 void swift::checkExplicitAvailability(Decl *decl) {
-  // Check only if the command line option was set.
-  if (!decl->getASTContext().LangOpts.RequireExplicitAvailability)
+  // Skip if the command line option was not set and
+  // accessors as we check the pattern binding decl instead.
+  if (!decl->getASTContext().LangOpts.RequireExplicitAvailability ||
+      isa<AccessorDecl>(decl))
     return;
 
-  // Skip nominal type members as the type should be annotated.
-  auto declContext = decl->getDeclContext();
-  if (isa<NominalTypeDecl>(declContext))
-    return;
+  // Only look at decls at module level or in extensions.
+  // This could be changed to force having attributes on all decls.
+  if (!decl->getDeclContext()->isModuleScopeContext() &&
+      !isa<ExtensionDecl>(decl->getDeclContext())) return;
 
-  ValueDecl *valueDecl = dyn_cast<ValueDecl>(decl);
-  if (valueDecl == nullptr) {
+  if (auto extension = dyn_cast<ExtensionDecl>(decl)) {
     // decl should be either a ValueDecl or an ExtensionDecl.
-    auto extension = cast<ExtensionDecl>(decl);
     auto extended = extension->getExtendedNominal();
     if (!extended || !extended->getFormalAccessScope().isPublic())
       return;
@@ -2916,6 +2916,18 @@ void swift::checkExplicitAvailability(Decl *decl) {
     });
 
     if (!hasMembers && !hasProtocols) return;
+
+  } else if (auto pbd = dyn_cast<PatternBindingDecl>(decl)) {
+    // Check the first var instead.
+    if (pbd->getNumPatternEntries() == 0)
+      return;
+
+    llvm::SmallVector<VarDecl *, 2> vars;
+    pbd->getPattern(0)->collectVariables(vars);
+    if (vars.empty())
+      return;
+
+    decl = vars.front();
   }
 
   if (declNeedsExplicitAvailability(decl)) {

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -1629,6 +1629,8 @@ class DeclChecker : public DeclVisitor<DeclChecker> {
 
     checkAccessControl(PBD);
 
+    checkExplicitAvailability(PBD);
+
     // If the initializers in the PBD aren't checked yet, do so now.
     for (auto i : range(PBD->getNumPatternEntries())) {
       if (!PBD->isInitialized(i))

test/attr/require_explicit_availability.swift

@@ -1,8 +1,7 @@
 // Test the -require-explicit-availability flag
 // REQUIRES: OS=macosx
 
-// RUN: %swiftc_driver -typecheck -parse-stdlib -target x86_64-apple-macosx10.10 -Xfrontend -verify -require-explicit-availability -require-explicit-availability-target "macOS 10.10"  %s
-// RUN: %swiftc_driver -typecheck -parse-stdlib -target x86_64-apple-macosx10.10 -warnings-as-errors %s
+// RUN: %swiftc_driver -typecheck -parse-as-library -target x86_64-apple-macosx10.10 -Xfrontend -verify -require-explicit-availability -require-explicit-availability-target "macOS 10.10"  %s
 
 public struct S { // expected-warning {{public declarations should have an availability attribute when building with -require-explicit-availability}}
   public func method() { }
@@ -91,3 +90,50 @@ public struct spiStruct {
 extension spiStruct {
   public func spiExtensionMethod() {}
 }
+
+public var publicVar = S() // expected-warning {{public declarations should have an availability attribute when building with -require-explicit-availability}} {{1-1=@available(macOS 10.10, *)\n}}
+
+@available(macOS 10.10, *)
+public var publicVarOk = S()
+
+public var (a, b) = (S(), S()) // expected-warning {{public declarations should have an availability attribute when building with -require-explicit-availability}} {{1-1=@available(macOS 10.10, *)\n}}
+
+@available(macOS 10.10, *)
+public var (c, d) = (S(), S())
+
+public var _ = S() // expected-error {{global variable declaration does not bind any variables}}
+
+public var implicitGet: S { // expected-warning {{public declarations should have an availability attribute when building with -require-explicit-availability}} {{1-1=@available(macOS 10.10, *)\n}}
+  return S()
+}
+
+@available(macOS 10.10, *)
+public var implicitGetOk: S {
+  return S()
+}
+
+public var computed: S { // expected-warning {{public declarations should have an availability attribute when building with -require-explicit-availability}} {{1-1=@available(macOS 10.10, *)\n}}
+  get { return S() }
+  set { }
+}
+
+public var computedHalf: S { // expected-warning {{public declarations should have an availability attribute when building with -require-explicit-availability}} {{1-1=@available(macOS 10.10, *)\n}}
+  @available(macOS 10.10, *)
+  get { return S() }
+  set { }
+}
+
+// FIXME the following warning is not needed.
+public var computedOk: S { // expected-warning {{public declarations should have an availability attribute when building with -require-explicit-availability}} {{1-1=@available(macOS 10.10, *)\n}}
+  @available(macOS 10.10, *)
+  get { return S() }
+
+  @available(macOS 10.10, *)
+  set { }
+}
+
+@available(macOS 10.10, *)
+public var computedOk1: S {
+  get { return S() }
+  set { }
+}