[cssimplify] add a fix for contextual type conversion for function type

Author: theblixguy

lib/Sema/CSDiag.cpp

@@ -2315,64 +2315,6 @@ bool FailureDiagnosis::diagnoseContextualConversionError(
       exprType->isEqual(contextualType)) {
     return false;
   }
-  
-  // If we're trying to convert something of type "() -> T" to T, then we
-  // probably meant to call the value.
-  if (auto srcFT = exprType->getAs<AnyFunctionType>()) {
-    if (srcFT->getParams().empty() &&
-        !isUnresolvedOrTypeVarType(srcFT->getResult()) &&
-        CS.TC.isConvertibleTo(srcFT->getResult(), contextualType, CS.DC)) {
-      diagnose(expr->getLoc(), diag::missing_nullary_call, srcFT->getResult())
-        .highlight(expr->getSourceRange())
-        .fixItInsertAfter(expr->getEndLoc(), "()");
-
-      // It is possible that we're looking at a stored property being
-      // initialized with a closure. Something like:
-      //
-      // var foo: Int = { return 0 }
-      //
-      // Let's offer another fix-it to remove the '=' to turn the stored
-      // property into a computed property. If the variable is immutable, then
-      // replace the 'let' with a 'var'
-
-      // First, check if the variable is declared top level or not. If it is
-      // not, then it means we're inside a decl like a class or an extension.
-      PatternBindingDecl *PBD = nullptr;
-
-      if (auto TLCD = dyn_cast<TopLevelCodeDecl>(CS.DC)) {
-        if (TLCD->getBody()->isImplicit()) {
-          if (auto decl = TLCD->getBody()->getElement(0).dyn_cast<Decl *>()) {
-            if (auto binding = dyn_cast<PatternBindingDecl>(decl)) {
-              PBD = binding;
-            }
-          }
-        }
-      } else if (auto PBI = dyn_cast<PatternBindingInitializer>(CS.DC)) {
-        PBD = PBI->getBinding();
-      }
-
-      if (PBD) {
-        if (auto VD = PBD->getSingleVar()) {
-          auto entry = PBD->getPatternEntryForVarDecl(VD);
-
-          if (!VD->isStatic() &&
-              !VD->getAttrs().getAttribute<DynamicReplacementAttr>() &&
-              entry.getInit() && isa<ClosureExpr>(entry.getInit())) {
-            auto diag = CS.TC.diagnose(expr->getLoc(),
-                                       diag::extension_stored_property_fixit,
-                                       VD->getName());
-            diag.fixItRemove(entry.getEqualLoc());
-
-            if (VD->isLet()) {
-              diag.fixItReplace(PBD->getStartLoc(), getTokenText(tok::kw_var));
-            }
-          }
-        }
-      }
-
-      return true;
-    }
-  }
 
   // If this is a conversion from T to () in a call argument context, it is
   // almost certainly an extra argument being passed in.

lib/Sema/CSDiagnostics.cpp

@@ -22,6 +22,7 @@
 #include "swift/AST/Decl.h"
 #include "swift/AST/Expr.h"
 #include "swift/AST/GenericSignature.h"
+#include "swift/AST/Initializer.h"
 #include "swift/AST/ParameterList.h"
 #include "swift/AST/Pattern.h"
 #include "swift/AST/ProtocolConformance.h"
@@ -1348,6 +1349,51 @@ bool ContextualFailure::diagnoseMissingFunctionCall() const {
                  srcFT->getResult())
       .highlight(anchor->getSourceRange())
       .fixItInsertAfter(anchor->getEndLoc(), "()");
+
+  // It is possible that we're looking at a stored property being
+  // initialized with a closure. Something like:
+  //
+  // var foo: Int = { return 0 }
+  //
+  // Let's offer another fix-it to remove the '=' to turn the stored
+  // property into a computed property. If the variable is immutable, then
+  // replace the 'let' with a 'var'
+
+  // First, check if the variable is declared top level or not. If it is
+  // not, then it means we're inside a decl like a class or an extension.
+  PatternBindingDecl *PBD = nullptr;
+
+  if (auto TLCD = dyn_cast<TopLevelCodeDecl>(getDC())) {
+    if (TLCD->getBody()->isImplicit()) {
+      if (auto decl = TLCD->getBody()->getElement(0).dyn_cast<Decl *>()) {
+        if (auto binding = dyn_cast<PatternBindingDecl>(decl)) {
+          PBD = binding;
+        }
+      }
+    }
+  } else if (auto PBI = dyn_cast<PatternBindingInitializer>(getDC())) {
+    PBD = PBI->getBinding();
+  }
+
+  if (PBD) {
+    if (auto VD = PBD->getSingleVar()) {
+      auto entry = PBD->getPatternEntryForVarDecl(VD);
+
+      if (!VD->isStatic() &&
+          !VD->getAttrs().getAttribute<DynamicReplacementAttr>() &&
+          entry.getInit() && isa<ClosureExpr>(entry.getInit())) {
+        auto diag =
+            TC.diagnose(anchor->getLoc(), diag::extension_stored_property_fixit,
+                        VD->getName());
+        diag.fixItRemove(entry.getEqualLoc());
+
+        if (VD->isLet()) {
+          diag.fixItReplace(PBD->getStartLoc(), getTokenText(tok::kw_var));
+        }
+      }
+    }
+  }
+
   return true;
 }
 

lib/Sema/CSSimplify.cpp

@@ -1989,6 +1989,17 @@ repairFailures(ConstraintSystem &cs, Type lhs, Type rhs,
     break;
   }
 
+  case ConstraintLocator::ContextualType: {
+    if (lhs->is<FunctionType>() && !rhs->is<AnyFunctionType>()) {
+      auto *fix = ContextualMismatch::create(cs, lhs, rhs,
+                                             cs.getConstraintLocator(locator));
+      conversionsOrFixes.push_back(fix);
+      break;
+    }
+
+    return;
+  }
+
   default:
     return;
   }