[SE-0099 Restructuring Condition Clauses] Flip the switch (#3441)

Now that some time has passed, switch the warnings to errors,
completing SE-0099.

Author: milseman

include/swift/AST/DiagnosticsParse.def

@@ -808,13 +808,8 @@ ERROR(expected_comma_stmtcondition,none,
 ERROR(expected_expr_conditional,PointsToFirstBadToken,
       "expected expression in conditional", ())
 
-// FIXME: Upgrade these two diagnostics to errors in Swift 3.
-WARNING(expected_binding_keyword,none,
+ERROR(expected_binding_keyword,none,
       "expected '%0' in conditional", (StringRef))
-// FIXME: just replace with expected_comma_stmtcondition
-WARNING(expected_comma_stmtcondition_w,none,
-        "expected ',' joining parts of a multi-clause condition", ())
-
 
 ERROR(expected_expr_conditional_var,PointsToFirstBadToken,
       "expected expression after '=' in conditional binding", ())

lib/Parse/ParseStmt.cpp

@@ -1188,7 +1188,7 @@ ParserStatus Parser::parseStmtCondition(StmtCondition &Condition,
     // they were in Swift 2 and earlier.
     SourceLoc whereLoc;
     if (consumeIf(tok::kw_where, whereLoc)) {
-      diagnose(whereLoc, diag::expected_comma_stmtcondition_w)
+      diagnose(whereLoc, diag::expected_comma_stmtcondition)
         .fixItReplace(whereLoc, ",");
       return true;
     }

test/Parse/recovery.swift

@@ -558,7 +558,7 @@ func f1() {
 
 // <rdar://problem/20489838> QoI: Nonsensical error and fixit if "let" is missing between 'if let ... where' clauses
 func testMultiPatternConditionRecovery(x: Int?) {
-  // expected-warning@+1 {{expected ',' joining parts of a multi-clause condition}} {{16-21=,}}
+  // expected-error@+1 {{expected ',' joining parts of a multi-clause condition}} {{16-21=,}}
   if let y = x where y == 0, let z = x {
     _ = y
     _ = z
@@ -568,7 +568,7 @@ func testMultiPatternConditionRecovery(x: Int?) {
     z = y; y = z
   }
 
-  if var y = x, z = x { // expected-warning {{expected 'var' in conditional}} {{17-17=var }}
+  if var y = x, z = x { // expected-error {{expected 'var' in conditional}} {{17-17=var }}
     z = y; y = z
   }
 

test/SILGen/if_while_binding.swift

@@ -134,7 +134,7 @@ func while_loop_multi() {
   // CHECK: br [[LOOP_EXIT0]]
 
   // CHECK: [[LOOP_BODY]]([[B:%[0-9]+]] : $String):
-  while let a = foo(), b = bar() {
+  while let a = foo(), let b = bar() {
     // CHECK:   debug_value [[B]] : $String, let, name "b"
     // CHECK:   debug_value [[A]] : $String, let, name "c"
     // CHECK:   release_value [[B]]
@@ -229,7 +229,7 @@ func if_multi_where() {
   // CHECK:   strong_release [[BBOX]]
   // CHECK:   release_value [[A]]
   // CHECK:   br [[IF_DONE:bb[0-9]+]]
-  if let a = foo(), var b = bar() where a == b {
+  if let a = foo(), var b = bar(), a == b {
     // CHECK: [[IF_BODY]]:
     // CHECK:   strong_release [[BBOX]]
     // CHECK:   release_value [[A]]

test/stmt/if_while_var.swift

@@ -61,7 +61,7 @@ if let x = opt, let y = opt, x != y,
 
 // Leading boolean conditional.
 if 1 != 2, let x = opt,
-   y = opt,  // expected-warning {{expected 'let' in conditional}} {{4-4=let }}
+   y = opt,  // expected-error {{expected 'let' in conditional}} {{4-4=let }}
    x != y,
    let a = opt, var b = opt {
 }