[SE-0290] Cleanup BuilderTransform for #unavailable

Author: rockbruno

lib/Sema/BuilderTransform.cpp

@@ -505,16 +505,16 @@ class BuilderClosureVisitor
     Expr *thenVarRefExpr = buildVarRef(
         thenVar, ifStmt->getThenStmt()->getEndLoc());
 
-    /// If there is a #available in the condition, wrap the 'then' in a call to 
-    /// buildLimitedAvailability(_:).
+    // If there is a #available in the condition, wrap the 'then' in a call to
+    // buildLimitedAvailability(_:).
     auto availabilityCond = findAvailabilityCondition(ifStmt->getCond());
-    bool supportsAvailable = availabilityCond && 
-                             builderSupports(ctx.Id_buildLimitedAvailability);
-    auto apiAvailability = availabilityCond->getAvailability();
-    if (supportsAvailable && !apiAvailability->isUnavailability()) {
-      thenVarRefExpr = buildCallIfWanted(
-          ifStmt->getThenStmt()->getEndLoc(), ctx.Id_buildLimitedAvailability,
-          { thenVarRefExpr }, { Identifier() });
+    bool supportsAvailability =
+        availabilityCond && builderSupports(ctx.Id_buildLimitedAvailability);
+    if (supportsAvailability &&
+        !availabilityCond->getAvailability()->isUnavailability()) {
+      thenVarRefExpr = buildCallIfWanted(ifStmt->getThenStmt()->getEndLoc(),
+                                         ctx.Id_buildLimitedAvailability,
+                                         {thenVarRefExpr}, {Identifier()});
     }
 
     // Prepare the `then` operand by wrapping it to produce a chain result.
@@ -530,25 +530,29 @@ class BuilderClosureVisitor
       assert(isOptional);
       elseLoc = ifStmt->getEndLoc();
       elseExpr = buildNoneExpr(elseLoc);
-    } else {
+
+    // - If there's an `else if`, the chain expression from that
+    //   should already be producing a chain result.
+    } else if (isElseIf) {
+      elseExpr = buildVarRef(*elseChainVar, ifStmt->getEndLoc());
       elseLoc = ifStmt->getElseLoc();
-      Expr *elseVarRefExpr = buildVarRef(*elseChainVar, ifStmt->getEndLoc());
-      /// If there is a #unavailable in the condition, wrap the 'else' in a call
-      /// to buildLimitedAvailability(_:).
-      if (supportsAvailable && apiAvailability->isUnavailability()) {
-        elseVarRefExpr = buildCallIfWanted(
-            ifStmt->getEndLoc(), ctx.Id_buildLimitedAvailability,
-            { elseVarRefExpr }, { Identifier() });
-      }
-      // - If there's an `else if`, the chain expression from that
-      //   should already be producing a chain result.
-      if (isElseIf) {
-        elseExpr = elseVarRefExpr;
+
       // - Otherwise, wrap it to produce a chain result.
-      } else {
-        elseExpr = buildWrappedChainPayload(
-            elseVarRefExpr, payloadIndex + 1, numPayloads, isOptional);
+    } else {
+      Expr *elseVarRefExpr = buildVarRef(*elseChainVar, ifStmt->getEndLoc());
+
+      // If there is a #unavailable in the condition, wrap the 'else' in a call
+      // to buildLimitedAvailability(_:).
+      if (supportsAvailability &&
+          availabilityCond->getAvailability()->isUnavailability()) {
+        elseVarRefExpr = buildCallIfWanted(ifStmt->getEndLoc(),
+                                           ctx.Id_buildLimitedAvailability,
+                                           {elseVarRefExpr}, {Identifier()});
       }
+
+      elseExpr = buildWrappedChainPayload(elseVarRefExpr, payloadIndex + 1,
+                                          numPayloads, isOptional);
+      elseLoc = ifStmt->getElseLoc();
     }
 
     // The operand should have optional type if we had optional results,

lib/Sema/TypeCheckAvailability.cpp

@@ -795,14 +795,15 @@ class TypeRefinementContextBuilder : private ASTWalker {
       FalseRefinement = FalseFlow;
     }
 
-    auto makeResult = ^(Optional<AvailabilityContext> TrueRefinement,
-                        Optional<AvailabilityContext> FalseRefinement) {
-      if (isUnavailability.hasValue() && isUnavailability.getValue()) {
-        // If this is an unavailability check, invert the result.
-        return std::make_pair(FalseRefinement, TrueRefinement);
-      }
-      return std::make_pair(TrueRefinement, FalseRefinement);
-    };
+    auto makeResult =
+        [isUnavailability](Optional<AvailabilityContext> TrueRefinement,
+                           Optional<AvailabilityContext> FalseRefinement) {
+          if (isUnavailability.hasValue() && isUnavailability.getValue()) {
+            // If this is an unavailability check, invert the result.
+            return std::make_pair(FalseRefinement, TrueRefinement);
+          }
+          return std::make_pair(TrueRefinement, FalseRefinement);
+        };
 
     if (NestedCount == 0)
       return makeResult(None, FalseRefinement);
@@ -823,9 +824,7 @@ class TypeRefinementContextBuilder : private ASTWalker {
     OtherPlatformAvailabilitySpec *FoundOtherSpec = nullptr;
     PlatformVersionConstraintAvailabilitySpec *BestSpec = nullptr;
 
-    auto Queries = available->getQueries();
-
-    for (auto *Spec : Queries) {
+    for (auto *Spec : available->getQueries()) {
       if (auto *OtherSpec = dyn_cast<OtherPlatformAvailabilitySpec>(Spec)) {
         FoundOtherSpec = OtherSpec;
         continue;

test/Constraints/result_builder_availability.swift

@@ -73,26 +73,32 @@ struct Only10_52 { }
 func globalFuncAvailableOn10_52() -> Only10_52 { .init() }
 
 tuplify(true) { cond in
-  var bool = true
   globalFuncAvailableOn10_9()
   if #available(OSX 10.51, *) {
     globalFuncAvailableOn10_51()
     tuplify(false) { cond2 in
-      if cond, #available(OSX 10.52, *) { // expected-warning{{result builder 'TupleBuilder' does not implement 'buildLimitedAvailability'; this code may crash on earlier versions of the OS}}
+      if cond, #available(OSX 10.52, *) { 
+        // expected-warning@-1{{result builder 'TupleBuilder' does not implement 'buildLimitedAvailability'; this code may crash on earlier versions of the OS}}
         cond2
         globalFuncAvailableOn10_52()
-      } else if bool {
+      } else if true {
+        globalFuncAvailableOn10_52() // expected-error{{'globalFuncAvailableOn10_52()' is only available in macOS 10.52 or newer}}
+        // expected-note@-1{{add 'if #available' version check}}
+      } else if false {
         globalFuncAvailableOn10_52() // expected-error{{'globalFuncAvailableOn10_52()' is only available in macOS 10.52 or newer}}
         // expected-note@-1{{add 'if #available' version check}}
       } else {
         globalFuncAvailableOn10_52() // expected-error{{'globalFuncAvailableOn10_52()' is only available in macOS 10.52 or newer}}
         // expected-note@-1{{add 'if #available' version check}}
       }
-      if cond, #unavailable(OSX 10.52) { // expected-warning{{result builder 'TupleBuilder' does not implement 'buildLimitedAvailability'; this code may crash on earlier versions of the OS}}
+      if cond, #unavailable(OSX 10.52) { 
+        // expected-warning@-1{{result builder 'TupleBuilder' does not implement 'buildLimitedAvailability'; this code may crash on earlier versions of the OS}}
         cond2
         globalFuncAvailableOn10_52() // expected-error{{'globalFuncAvailableOn10_52()' is only available in macOS 10.52 or newer}}
         // expected-note@-1{{add 'if #available' version check}}
-      } else if bool {
+      } else if true {
+        globalFuncAvailableOn10_52()
+      } else if false {
         globalFuncAvailableOn10_52()
       } else {
         globalFuncAvailableOn10_52()
@@ -148,21 +154,12 @@ func tuplifyWithAvailabilityErasure<T>(_ cond: Bool, @TupleBuilderAvailability b
 }
 
 tuplifyWithAvailabilityErasure(true) { cond in
-  var bool = true
   if cond, #available(OSX 10.52, *) {
     globalFuncAvailableOn10_52()
-  } else if bool {
-    globalFuncAvailableOn10_52() // expected-error{{'globalFuncAvailableOn10_52()' is only available in macOS 10.52 or newer}}
-    // expected-note@-1{{add 'if #available' version check}}
-  } else {
-    globalFuncAvailableOn10_52() // expected-error{{'globalFuncAvailableOn10_52()' is only available in macOS 10.52 or newer}}
-    // expected-note@-1{{add 'if #available' version check}}
   }
+
   if cond, #unavailable(OSX 10.52) {
-    globalFuncAvailableOn10_52() // expected-error{{'globalFuncAvailableOn10_52()' is only available in macOS 10.52 or newer}}
-    // expected-note@-1{{add 'if #available' version check}}
-  } else if bool {
-    globalFuncAvailableOn10_52()
+    cond
   } else {
     globalFuncAvailableOn10_52()
   }