[Multi-expression closures] Add support for break & continue statements.

Author: DougGregor

lib/Sema/CSClosure.cpp

@@ -172,6 +172,9 @@ class ClosureConstraintGenerator
     visit(whileStmt->getBody());
   }
 
+  void visitBreakStmt(BreakStmt *breakStmt) { }
+  void visitContinueStmt(ContinueStmt *continueStmt) { }
+
 #define UNSUPPORTED_STMT(STMT) void visit##STMT##Stmt(STMT##Stmt *) { \
       llvm_unreachable("Unsupported statement kind " #STMT);          \
   }
@@ -180,8 +183,6 @@ class ClosureConstraintGenerator
   UNSUPPORTED_STMT(DoCatch)
   UNSUPPORTED_STMT(Switch)
   UNSUPPORTED_STMT(Case)
-  UNSUPPORTED_STMT(Break)
-  UNSUPPORTED_STMT(Continue)
   UNSUPPORTED_STMT(Fallthrough)
   UNSUPPORTED_STMT(Fail)
   UNSUPPORTED_STMT(Throw)
@@ -213,6 +214,10 @@ class ClosureConstraintApplication
   RewriteTargetFn rewriteTarget;
   bool isSingleExpression;
 
+  ASTContext &getASTContext() const {
+    return solution.getConstraintSystem().getASTContext();
+  }
+
 public:
   /// Whether an error was encountered while generating constraints.
   bool hadError = false;
@@ -412,6 +417,29 @@ class ClosureConstraintApplication
     return whileStmt;
   }
 
+  ASTNode visitBreakStmt(BreakStmt *breakStmt) {
+    if (auto target = findBreakOrContinueStmtTarget(
+            getASTContext(), closure->getParentSourceFile(), breakStmt->getLoc(),
+            breakStmt->getTargetName(), breakStmt->getTargetLoc(),
+            /*isContinue=*/false, closure, { })) {
+      breakStmt->setTarget(target);
+    }
+
+    return breakStmt;
+  }
+
+  ASTNode visitContinueStmt(ContinueStmt *continueStmt) {
+    if (auto target = findBreakOrContinueStmtTarget(
+            getASTContext(), closure->getParentSourceFile(),
+            continueStmt->getLoc(), continueStmt->getTargetName(),
+            continueStmt->getTargetLoc(), /*isContinue=*/true,
+            closure, { })) {
+      continueStmt->setTarget(target);
+    }
+
+    return continueStmt;
+  }
+
 #define UNSUPPORTED_STMT(STMT) ASTNode visit##STMT##Stmt(STMT##Stmt *) { \
       llvm_unreachable("Unsupported statement kind " #STMT);          \
   }
@@ -420,8 +448,6 @@ class ClosureConstraintApplication
   UNSUPPORTED_STMT(DoCatch)
   UNSUPPORTED_STMT(Switch)
   UNSUPPORTED_STMT(Case)
-  UNSUPPORTED_STMT(Break)
-  UNSUPPORTED_STMT(Continue)
   UNSUPPORTED_STMT(Fallthrough)
   UNSUPPORTED_STMT(Fail)
   UNSUPPORTED_STMT(Throw)

lib/Sema/TypeCheckStmt.cpp

@@ -401,7 +401,7 @@ static LabeledStmt *findUnlabeledBreakOrContinueStmtTarget(
 ///
 /// \returns the target, if one was found, or \c nullptr if no such target
 /// exists.
-static LabeledStmt *findBreakOrContinueStmtTarget(
+LabeledStmt *swift::findBreakOrContinueStmtTarget(
     ASTContext &ctx, SourceFile *sourceFile,
     SourceLoc loc, Identifier targetName, SourceLoc targetLoc,
     bool isContinue, DeclContext *dc,

lib/Sema/TypeChecker.h

@@ -1365,6 +1365,16 @@ bool areGenericRequirementsSatisfied(const DeclContext *DC,
                                      SubstitutionMap Substitutions,
                                      bool isExtension);
 
+/// Find the target of a break or continue statement.
+///
+/// \returns the target, if one was found, or \c nullptr if no such target
+/// exists.
+LabeledStmt *findBreakOrContinueStmtTarget(
+    ASTContext &ctx, SourceFile *sourceFile,
+    SourceLoc loc, Identifier targetName, SourceLoc targetLoc,
+    bool isContinue, DeclContext *dc,
+    ArrayRef<LabeledStmt *> oldActiveLabeledStmts);
+
 /// Check for restrictions on the use of the @unknown attribute on a
 /// case statement.
 void checkUnknownAttrRestrictions(

test/expr/closure/multi_statement.swift

@@ -29,11 +29,19 @@ func mapWithMoreStatements(ints: [Int]) {
       actualValue += 1
     }
 
+  my_repeat:
     repeat {
       print("still here")
+
+      if i % 7 == 0 {
+        break my_repeat
+      }
     } while random(i)
 
     for j in 0..<i where j % 2 == 0 {
+      if j % 7 == 0 {
+        continue
+      }
       print("even")
     }