From 61011ba5840df8962f09ebc1766c868a950aea37 Mon Sep 17 00:00:00 2001
From: Elias Naur <elias.naur@gmail.com>
Date: Wed, 14 Sep 2016 18:04:50 +0200
Subject: [PATCH] bind: fix error type

Errors was recently converted to use objects as representation instead
of strings. Issue golang/go#17073 exposed a few places that wasn't properly
updated. Fix them and add the test case from the the issue.

Fixes golang/go#17073

Change-Id: I0191993a8427d930540716407fc09032f282fc66
Reviewed-on: https://go-review.googlesource.com/29176
Reviewed-by: David Crawshaw <crawshaw@golang.org>
---
 bind/genjava.go                        | 5 ++++-
 bind/genobjc.go                        | 2 +-
 bind/java/SeqTest.java                 | 6 +++---
 bind/objc/SeqTest.m                    | 9 +++++++++
 bind/testdata/issue12328.java.golden   | 8 ++++----
 bind/testdata/issue12328.objc.h.golden | 4 ++--
 bind/testpkg/testpkg.go                | 4 ++++
 7 files changed, 27 insertions(+), 11 deletions(-)

diff --git a/bind/genjava.go b/bind/genjava.go
index a36333d..9653563 100644
--- a/bind/genjava.go
+++ b/bind/genjava.go
@@ -308,7 +308,7 @@ func (g *JavaGen) javaType(T types.Type) string {
 		// The error type is usually translated into an exception in
 		// Java, however the type can be exposed in other ways, such
 		// as an exported field.
-		return "String"
+		return "java.lang.Exception"
 	}
 	switch T := T.(type) {
 	case *types.Basic:
@@ -906,6 +906,9 @@ func (g *JavaGen) jniClassSigPrefix(pkg *types.Package) string {
 }
 
 func (g *JavaGen) jniSigType(T types.Type) string {
+	if isErrorType(T) {
+		return "Ljava/lang/Exception;"
+	}
 	switch T := T.(type) {
 	case *types.Basic:
 		switch T.Kind() {
diff --git a/bind/genobjc.go b/bind/genobjc.go
index 4a936bf..74045ff 100644
--- a/bind/genobjc.go
+++ b/bind/genobjc.go
@@ -964,7 +964,7 @@ func (g *objcGen) refTypeBase(typ types.Type) string {
 
 func (g *objcGen) objcFieldType(t types.Type) string {
 	if isErrorType(t) {
-		return "NSString*"
+		return "NSError*"
 	}
 	return g.objcType(t)
 }
diff --git a/bind/java/SeqTest.java b/bind/java/SeqTest.java
index c81b682..6348e01 100644
--- a/bind/java/SeqTest.java
+++ b/bind/java/SeqTest.java
@@ -418,9 +418,9 @@ public class SeqTest extends InstrumentationTestCase {
   public void testErrorField() {
     final String want = "an error message";
     Node n = Testpkg.newNode("ErrTest");
-    n.setErr(want);
-    String got = n.getErr();
-    assertEquals("want back the error message we set", want, got);
+    n.setErr(new Exception(want));
+    Exception got = n.getErr();
+    assertEquals("want back the error message we set", want, got.getMessage());
   }
 
   //test if we have JNI local reference table overflow error
diff --git a/bind/objc/SeqTest.m b/bind/objc/SeqTest.m
index 58519bf..7709131 100644
--- a/bind/objc/SeqTest.m
+++ b/bind/objc/SeqTest.m
@@ -294,6 +294,15 @@ static int numI = 0;
 	XCTAssertTrue(GoTestpkgCallIError(num, NO, &error2), @"GoTestpkgCallIError(Number, NO) failed(%@); want success", error2);
 }
 
+- (void)testErrorField {
+	NSString *want = @"an error message";
+	GoTestpkgNode *n = GoTestpkgNewNode(@"ErrTest");
+	n.err = [NSError errorWithDomain:@"SeqTest" code:1 userInfo:@{NSLocalizedDescriptionKey: want}];
+	NSError *got = n.err;
+	NSString *gotMsg = [got.userInfo valueForKey:NSLocalizedDescriptionKey];
+	XCTAssertEqualObjects(gotMsg, want, @"err = %@, want %@", gotMsg, want);
+}
+
 - (void)testVar {
 	NSString *s = GoTestpkg.stringVar;
 	XCTAssertEqualObjects(s, @"a string var", @"GoTestpkg.StringVar = %@, want 'a string var'", s);
diff --git a/bind/testdata/issue12328.java.golden b/bind/testdata/issue12328.java.golden
index 52f0d70..fb92fc0 100644
--- a/bind/testdata/issue12328.java.golden
+++ b/bind/testdata/issue12328.java.golden
@@ -9,16 +9,16 @@ import go.Seq;
 public final class T extends Seq.Proxy {
     private T(go.Seq.Ref ref) { super(ref); }
     
-    public final native String getErr();
-    public final native void setErr(String v);
+    public final native java.lang.Exception getErr();
+    public final native void setErr(java.lang.Exception v);
     
     @Override public boolean equals(Object o) {
         if (o == null || !(o instanceof T)) {
             return false;
         }
         T that = (T)o;
-        String thisErr = getErr();
-        String thatErr = that.getErr();
+        java.lang.Exception thisErr = getErr();
+        java.lang.Exception thatErr = that.getErr();
         if (thisErr == null) {
             if (thatErr != null) {
                 return false;
diff --git a/bind/testdata/issue12328.objc.h.golden b/bind/testdata/issue12328.objc.h.golden
index 6ab1b99..5e36fc8 100644
--- a/bind/testdata/issue12328.objc.h.golden
+++ b/bind/testdata/issue12328.objc.h.golden
@@ -16,8 +16,8 @@
 @property(strong, readonly) id _ref;
 
 - (id)initWithRef:(id)ref;
-- (NSString*)err;
-- (void)setErr:(NSString*)v;
+- (NSError*)err;
+- (void)setErr:(NSError*)v;
 @end
 
 #endif
diff --git a/bind/testpkg/testpkg.go b/bind/testpkg/testpkg.go
index 0df80e4..a812e9e 100644
--- a/bind/testpkg/testpkg.go
+++ b/bind/testpkg/testpkg.go
@@ -533,3 +533,7 @@ func NewInitCaller() *InitCaller {
 }
 
 func (ic *InitCaller) Init() {}
+
+type Issue17073 interface {
+	OnError(err error)
+}