[Sema] Build TRC for delayed functions bodies

lib/Sema/TypeCheckAvailability.cpp

@@ -916,6 +916,25 @@ void TypeChecker::buildTypeRefinementContextHierarchy(SourceFile &SF) {
   }
 }
 
+void TypeChecker::buildTypeRefinementContextHierarchyDelayed(SourceFile &SF, AbstractFunctionDecl *AFD) {
+  // If there's no TRC for the file, we likely don't want this one either.
+  // RootTRC is not set when availability checking is disabled.
+  TypeRefinementContext *RootTRC = SF.getTypeRefinementContext();
+  if(!RootTRC)
+    return;
+
+  if (AFD->getBodyKind() != AbstractFunctionDecl::BodyKind::Unparsed)
+    return;
+
+  // Parse the function body.
+  AFD->getBody(/*canSynthesize=*/true);
+
+  // Build the refinement context for the function body.
+  ASTContext &Context = SF.getASTContext();
+  TypeRefinementContextBuilder Builder(RootTRC, Context);
+  Builder.build(AFD);
+}
+
 TypeRefinementContext *
 TypeChecker::getOrBuildTypeRefinementContext(SourceFile *SF) {
   TypeRefinementContext *TRC = SF->getTypeRefinementContext();

lib/Sema/TypeChecker.cpp

@@ -252,6 +252,9 @@ static void typeCheckDelayedFunctions(SourceFile &SF) {
   while (currentFunctionIdx < SF.DelayedFunctions.size()) {
     auto *AFD = SF.DelayedFunctions[currentFunctionIdx];
     assert(!AFD->getDeclContext()->isLocalContext());
+
+    TypeChecker::buildTypeRefinementContextHierarchyDelayed(SF, AFD);
+
     (void) AFD->getTypecheckedBody();
     ++currentFunctionIdx;
   }

lib/Sema/TypeChecker.h

@@ -961,6 +961,10 @@ AvailabilityContext overApproximateAvailabilityAtLocation(
 /// Walk the AST to build the hierarchy of TypeRefinementContexts
 void buildTypeRefinementContextHierarchy(SourceFile &SF);
 
+/// Walk the AST to complete the hierarchy of TypeRefinementContexts for
+/// the delayed function body of \p AFD.
+void buildTypeRefinementContextHierarchyDelayed(SourceFile &SF, AbstractFunctionDecl *AFD);
+
 /// Build the hierarchy of TypeRefinementContexts for the entire
 /// source file, if it has not already been built. Returns the root
 /// TypeRefinementContext for the source file.

test/Sema/availability_and_delayed_parsing.swift

@@ -0,0 +1,49 @@
+/// Check for reliable availability checking in inlinable code even when
+/// skipping some function bodies. rdar://82269657
+
+// RUN: %target-swift-frontend -typecheck -dump-type-refinement-contexts %s -target x86_64-apple-macos10.10 2>&1 \
+// RUN:    | %FileCheck %s --check-prefixes TRC-API,TRC-INLINABLE,TRC-WITHTYPES,TRC-FULL
+// RUN: %target-swift-frontend -typecheck -dump-type-refinement-contexts %s -target x86_64-apple-macos10.10 -experimental-skip-non-inlinable-function-bodies-without-types 2>&1 \
+// RUN:    | %FileCheck %s --check-prefixes TRC-API,TRC-INLINABLE,TRC-WITHTYPES,TRC-FULL-NOT
+// RUN: %target-swift-frontend -typecheck -dump-type-refinement-contexts %s -target x86_64-apple-macos10.10 -experimental-skip-non-inlinable-function-bodies 2>&1 \
+// RUN:    | %FileCheck %s --check-prefixes TRC-API,TRC-INLINABLE,TRC-WITHTYPES-NOT,TRC-FULL-NOT
+// RUN: %target-swift-frontend -typecheck -dump-type-refinement-contexts %s -target x86_64-apple-macos10.10 -experimental-skip-all-function-bodies 2>&1 \
+// RUN:    | %FileCheck %s --check-prefixes TRC-API,TRC-INLINABLE-NOT,TRC-WITHTYPES-NOT,TRC-FULL-NOT
+
+// REQUIRES: OS=macosx
+
+@available(macOS 10.12, *)
+public func foo() { }
+// TRC-API: (root versions=[10.10.0,+Inf)
+// TRC-API:   (decl versions=[10.12,+Inf) decl=foo()
+
+@inlinable public func inlinableFunc() {
+    if #available(macOS 10.12, *) {
+        foo()
+    }
+}
+// TRC-INLINABLE:  (condition_following_availability versions=[10.12,+Inf)
+// TRC-INLINABLE:  (if_then versions=[10.12,+Inf)
+// TRC-INLINABLE-NOT-NOT:  (condition_following_availability versions=[10.12,+Inf)
+// TRC-INLINABLE-NOT-NOT:  (if_then versions=[10.12,+Inf)
+
+public func funcWithType() {
+    struct S {}
+    if #available(macOS 10.13, *) {
+        foo()
+    }
+}
+// TRC-WITHTYPES:  (condition_following_availability versions=[10.13,+Inf)
+// TRC-WITHTYPES:  (if_then versions=[10.13,+Inf)
+// TRC-WITHTYPES-NOT-NOT:  (condition_following_availability versions=[10.13,+Inf)
+// TRC-WITHTYPES-NOT-NOT:  (if_then versions=[10.13,+Inf)
+
+public func funcSkippable() {
+    if #available(macOS 10.14, *) {
+        foo()
+    }
+}
+// TRC-FULL:  (condition_following_availability versions=[10.14,+Inf)
+// TRC-FULL:  (if_then versions=[10.14,+Inf)
+// TRC-FULL-NOT-NOT:  (condition_following_availability versions=[10.14,+Inf)
+// TRC-FULL-NOT-NOT:  (if_then versions=[10.14,+Inf)