[Multi-expression closures] Add support for remaining declarations

Author: DougGregor

lib/Sema/CSClosure.cpp

@@ -43,21 +43,6 @@ class ClosureConstraintGenerator
 
 private:
   void visitDecl(Decl *decl) {
-    // Just ignore #if; the chosen children should appear in the
-    // surrounding context.  This isn't good for source tools but it
-    // at least works.
-    if (isa<IfConfigDecl>(decl))
-      return;
-
-    // Skip #warning/#error; we'll handle them when applying the closure.
-    if (isa<PoundDiagnosticDecl>(decl))
-      return;
-
-    // Ignore variable declarations, because they're always handled within
-    // their enclosing pattern bindings.
-    if (isa<VarDecl>(decl))
-      return;
-
     // Generate constraints for pattern binding declarations.
     if (auto patternBinding = dyn_cast<PatternBindingDecl>(decl)) {
       SolutionApplicationTarget target(patternBinding);
@@ -67,7 +52,12 @@ class ClosureConstraintGenerator
       return;
     }
 
-    llvm_unreachable("Unimplemented case for closure body");
+    // Ignore variable declarations, because they're always handled within
+    // their enclosing pattern bindings.
+    if (isa<VarDecl>(decl))
+      return;
+
+    // Other declarations will be handled at application time.
   }
 
   void visitBraceStmt(BraceStmt *braceStmt) {
@@ -334,7 +324,14 @@ class ClosureConstraintApplication
       return;
     }
 
-    llvm_unreachable("Declarations not supported");
+    // Just ignore #if; the chosen children should appear in the
+    // surrounding context.  This isn't good for source tools but it
+    // at least works.
+    if (isa<IfConfigDecl>(decl))
+      return;
+
+    // Type check the declaration.
+    TypeChecker::typeCheckDecl(decl);
   }
 
   ASTNode visitBraceStmt(BraceStmt *braceStmt) {

test/expr/closure/multi_statement.swift

@@ -80,6 +80,17 @@ func mapWithMoreStatements(ints: [Int], state: State) throws {
 
     #assert(true)
 
+    // expected-warning@+1{{danger zone}}
+    #warning("danger zone")
+
+#if false
+    struct NothingHere { }
+#else
+    struct NestedStruct {
+      var x: Int
+    }
+#endif
+
     do {
       print(try mightThrow())
     } catch let e as MyError {