[Multi-expression closures] Add support for experimental #assert statement

Author: DougGregor

lib/Sema/CSClosure.cpp

@@ -193,6 +193,22 @@ class ClosureConstraintGenerator
     cs.setSolutionApplicationTarget(throwStmt, target);
   }
 
+  void visitPoundAssertStmt(PoundAssertStmt *poundAssertStmt) {
+    auto *boolDecl = cs.getASTContext().getBoolDecl();
+    if (!boolDecl) {
+      hadError = true;
+      return;
+    }
+
+    SolutionApplicationTarget target(
+        poundAssertStmt->getCondition(), closure, CTP_Condition,
+        boolDecl->getDeclaredInterfaceType(), /*isDiscarded=*/false);
+    if (cs.generateConstraints(target, FreeTypeVariableBinding::Disallow))
+      hadError = true;
+
+    cs.setSolutionApplicationTarget(poundAssertStmt, target);
+  }
+
 #define UNSUPPORTED_STMT(STMT) void visit##STMT##Stmt(STMT##Stmt *) { \
       llvm_unreachable("Unsupported statement kind " #STMT);          \
   }
@@ -202,7 +218,6 @@ class ClosureConstraintGenerator
   UNSUPPORTED_STMT(Case)
   UNSUPPORTED_STMT(Fallthrough)
   UNSUPPORTED_STMT(Fail)
-  UNSUPPORTED_STMT(PoundAssert)
 #undef UNSUPPORTED_STMT
 };
 
@@ -467,7 +482,7 @@ class ClosureConstraintApplication
   }
 
   ASTNode visitThrowStmt(ThrowStmt *throwStmt) {
-    // Rewrite the condition.
+    // Rewrite the error.
     auto target = *solution.getConstraintSystem()
         .getSolutionApplicationTarget(throwStmt);
     if (auto result = rewriteTarget(target))
@@ -477,6 +492,17 @@ class ClosureConstraintApplication
     return throwStmt;
   }
 
+  ASTNode visitPoundAssertStmt(PoundAssertStmt *poundAssertStmt) {
+    // Rewrite the condition.
+    auto target = *solution.getConstraintSystem()
+        .getSolutionApplicationTarget(poundAssertStmt);
+    if (auto result = rewriteTarget(target))
+      poundAssertStmt->setCondition(result->getAsExpr());
+    else
+      hadError = true;
+    return poundAssertStmt;
+  }
+
 #define UNSUPPORTED_STMT(STMT) ASTNode visit##STMT##Stmt(STMT##Stmt *) { \
       llvm_unreachable("Unsupported statement kind " #STMT);          \
   }
@@ -486,7 +512,6 @@ class ClosureConstraintApplication
   UNSUPPORTED_STMT(Case)
   UNSUPPORTED_STMT(Fallthrough)
   UNSUPPORTED_STMT(Fail)
-  UNSUPPORTED_STMT(PoundAssert)
 #undef UNSUPPORTED_STMT
 
 };

test/expr/closure/multi_statement.swift

@@ -1,4 +1,4 @@
-// RUN: %target-typecheck-verify-swift -swift-version 5 -experimental-multi-statement-closures
+// RUN: %target-typecheck-verify-swift -swift-version 5 -experimental-multi-statement-closures -enable-experimental-static-assert
 
 func isInt<T>(_ value: T) -> Bool {
   return value is Int
@@ -50,11 +50,13 @@ func mapWithMoreStatements(ints: [Int]) throws {
       if j % 7 == 0 {
         continue
       }
- 
+
       print("even")
       throw MyError.featureIsTooCool
     }
 
+    #assert(true)
+
     return String(value)
   }
 }