bind: accept implicit self parameters in all methods

This is the ObjC equiivalent to CL 30276. It expands support for
implicit `self` parameters to every exported method.

Change-Id: Iff8a956b38448213866a93dc02ca59cac592feef
Reviewed-on: https://go-review.googlesource.com/30277
Reviewed-by: David Crawshaw <crawshaw@golang.org>

bind/genobjc.go

@@ -405,7 +405,7 @@ type funcSummary struct {
 	ret               string
 	sig               *types.Signature
 	params, retParams []paramInfo
-	hasthis           bool
+	hasself           bool
 }
 
 type paramInfo struct {
@@ -429,31 +429,25 @@ func (g *ObjcGen) funcSummary(oinf *objcClassInfo, obj *types.Func) *funcSummary
 	}
 	params := sig.Params()
 	first := 0
-	if om != nil {
-		// Check the implicit this argument and the argument count of the overridden method
-		excess := params.Len() - len(om.Params)
-		if excess < 0 {
-			g.errorf("method %s has fewer arguments than the method it overrides", obj.Name())
-		} else if excess > 1 {
-			g.errorf("overriding method %s has more arguments than the method it overrides", obj.Name())
-		} else if excess == 1 {
-			s.hasthis = true
-			first = 1
-			t := params.At(0).Type()
-			if !isObjcType(t) {
-				g.errorf("the `this` argument to method %s is not a ObjC type", obj.Name())
-				return s
-			} else {
-				ot := g.wrapMap[t.(*types.Named).Obj().Name()]
-				found := false
-				for _, sup := range oinf.supers {
-					if ot == sup {
-						found = true
-						break
+	if oinf != nil {
+		if params.Len() > 0 {
+			v := params.At(0)
+			if v.Name() == "self" {
+				t := v.Type()
+				if isObjcType(t) {
+					s.hasself = true
+					first = 1
+					ot := g.wrapMap[t.(*types.Named).Obj().Name()]
+					found := false
+					for _, sup := range oinf.supers {
+						if ot == sup {
+							found = true
+							break
+						}
+					}
+					if !found {
+						g.errorf("the type %s of the `this` argument to method %s is not a super class of the enclosing struct", ot.Name, obj.Name())
 					}
-				}
-				if !found {
-					g.errorf("the type %s of the `this` argument to method %s is not a super class of the enclosing struct", ot.Name, obj.Name())
 				}
 			}
 		}
@@ -740,7 +734,7 @@ func (g *ObjcGen) genRead(toName, fromName string, t types.Type, mode varMode) {
 func (g *ObjcGen) genFunc(s *funcSummary, objName string) {
 	if objName != "" {
 		g.Printf("int32_t refnum = go_seq_go_to_refnum(self._ref);\n")
-		if s.hasthis {
+		if s.hasself {
 			g.genRefWrite("self")
 		}
 	}
@@ -759,7 +753,7 @@ func (g *ObjcGen) genFunc(s *funcSummary, objName string) {
 	g.Printf("proxy%s_%s_%s(", g.pkgPrefix, objName, s.goname)
 	if objName != "" {
 		g.Printf("refnum")
-		if s.hasthis {
+		if s.hasself {
 			g.Printf(", _self")
 		}
 	}

bind/objc/SeqWrappers.m

@@ -62,9 +62,9 @@
 
 - (void)testClass {
 	GoObjcpkgGoNSDate *d = [[GoObjcpkgGoNSDate alloc] init];
-	NSString *desc = [d description]; // Also stores this
-	XCTAssertEqual(d, [d this], "GoNSDate this not identical");
-	XCTAssertEqual(GoObjcpkgHash, [d hash], "GoNSDate this not identical");
+	NSString *desc = [d description];
+	XCTAssertEqual(d, [d getSelf], "GoNSDate self not identical");
+	XCTAssertEqual(GoObjcpkgHash, [d hash], "GoNSDate hash not identical");
 	XCTAssertTrue([desc isEqualToString:GoObjcpkgDescriptionStr], "GoNSDate description mismatch: %@", desc);
 	GoObjcpkgGoUIResponder *resp = [[GoObjcpkgGoUIResponder alloc] init];
 	[resp pressesBegan:nil withEvent:nil];
@@ -79,7 +79,7 @@
 	};
 	NSString *superDesc = ((NSString *(*)(struct objc_super*, SEL))objc_msgSendSuper)(&_super, @selector(description));
 	XCTAssertTrue([superDesc isEqualToString:[o description]], "GoNSObject description mismatch");
-	[o setUseThis:TRUE];
+	[o setUseSelf:TRUE];
 	XCTAssertTrue([GoObjcpkgDescriptionStr isEqualToString:[o description]], "GoNSObject description mismatch");
 }
 

bind/testpkg/objcpkg/classes.go

@@ -16,24 +16,22 @@ const (
 
 type GoNSDate struct {
 	Foundation.NSDate
-	this Foundation.NSDate
 }
 
-func (d *GoNSDate) Hash(this Foundation.NSDate) int {
+func (d *GoNSDate) Hash(self Foundation.NSDate) int {
 	return Hash
 }
 
-func (d *GoNSDate) Description(this Foundation.NSDate) string {
-	// Test this call
-	if h := this.Hash(); h != Hash {
+func (d *GoNSDate) Description(self Foundation.NSDate) string {
+	// Test self call
+	if h := self.Hash(); h != Hash {
 		panic("hash mismatch")
 	}
-	d.this = this
 	return DescriptionStr
 }
 
-func (d *GoNSDate) This() Foundation.NSDate {
-	return d.this
+func (d *GoNSDate) GetSelf(self Foundation.NSDate) Foundation.NSDate {
+	return self
 }
 
 func NewGoNSDate() *GoNSDate {
@@ -43,14 +41,14 @@ func NewGoNSDate() *GoNSDate {
 type GoNSObject struct {
 	C       Foundation.NSObjectC // The class
 	P       Foundation.NSObjectP // The protocol
-	UseThis bool
+	UseSelf bool
 }
 
-func (o *GoNSObject) Description(this Foundation.NSObjectC) string {
-	if o.UseThis {
+func (o *GoNSObject) Description(self Foundation.NSObjectC) string {
+	if o.UseSelf {
 		return DescriptionStr
 	} else {
-		return this.Super().Description()
+		return self.Super().Description()
 	}
 }