gc: bug299, bug300

R=ken2
CC=golang-dev
https://golang.org/cl/1731057

src/cmd/gc/go.h

@@ -209,6 +209,7 @@ struct	Node
 	uchar	dodata;		// compile literal assignment as data statement
 	uchar	used;
 	uchar	isddd;
+	uchar	paren;	// was parenthesized
 	uchar	pun;		// dont registerize variable ONAME
 
 	// most nodes

src/cmd/gc/go.y

@@ -832,6 +832,7 @@ pexpr:
 |	'(' expr_or_type ')'
 	{
 		$$ = $2;
+		$$->paren++;
 	}
 |	pexpr '.' '(' expr_or_type ')'
 	{
@@ -874,6 +875,8 @@ pexpr:
 	}
 |	pexpr '{' braced_keyval_list '}'
 	{
+		if($1->paren)
+			yyerror("cannot parenthesize type in composite literal");
 		// composite expression
 		$$ = nod(OCOMPLIT, N, $1);
 		$$->list = $3;
@@ -963,6 +966,7 @@ ntype:
 |	'(' ntype ')'
 	{
 		$$ = $2;
+		$$->paren++;
 	}
 
 non_expr_type:
@@ -982,6 +986,7 @@ non_recvchantype:
 |	'(' ntype ')'
 	{
 		$$ = $2;
+		$$->paren++;
 	}
 
 convtype:
@@ -1141,6 +1146,8 @@ fndcl:
 			yyerror("bad receiver in method");
 			break;
 		}
+		if(rcvr->right->paren || (rcvr->right->op == OIND && rcvr->right->left->paren))
+			yyerror("cannot parenthesize receiver type");
 
 		$$ = nod(ODCLFUNC, N, N);
 		$$->nname = methodname1(name, rcvr->right);
@@ -1273,12 +1280,32 @@ structdcl:
 		$1->val = $2;
 		$$ = list1($1);
 	}
+|	'(' embed ')' oliteral
+	{
+		$2->val = $4;
+		$$ = list1($2);
+		yyerror("cannot parenthesize embedded type");
+	}
 |	'*' embed oliteral
 	{
 		$2->right = nod(OIND, $2->right, N);
 		$2->val = $3;
 		$$ = list1($2);
 	}
+|	'(' '*' embed ')' oliteral
+	{
+		$3->right = nod(OIND, $3->right, N);
+		$3->val = $5;
+		$$ = list1($3);
+		yyerror("cannot parenthesize embedded type");
+	}
+|	'*' '(' embed ')' oliteral
+	{
+		$3->right = nod(OIND, $3->right, N);
+		$3->val = $5;
+		$$ = list1($3);
+		yyerror("cannot parenthesize embedded type");
+	}
 
 packname:
 	LNAME
@@ -1319,6 +1346,11 @@ interfacedcl:
 	{
 		$$ = nod(ODCLFIELD, N, oldname($1));
 	}
+|	'(' packname ')'
+	{
+		$$ = nod(ODCLFIELD, N, oldname($2));
+		yyerror("cannot parenthesize embedded type");
+	}
 
 indcl:
 	'(' oarg_type_list_ocomma ')' fnres

src/pkg/reflect/all_test.go

@@ -170,33 +170,31 @@ var valueTests = []pair{
 	pair{(bool)(false), "true"},
 	pair{(*int8)(nil), "*int8(0)"},
 	pair{(**int8)(nil), "**int8(0)"},
-	pair{([5]int32){}, "[5]int32{0, 0, 0, 0, 0}"},
+	pair{[5]int32{}, "[5]int32{0, 0, 0, 0, 0}"},
 	pair{(**integer)(nil), "**reflect_test.integer(0)"},
 	pair{(map[string]int32)(nil), "map[string] int32{<can't iterate on maps>}"},
 	pair{(chan<- string)(nil), "chan<- string"},
-	pair{(struct {
+	pair{struct {
 		c chan *int32
 		d float32
-	}){},
+	}{},
 		"struct { c chan *int32; d float32 }{chan *int32, 0}",
 	},
 	pair{(func(a int8, b int32))(nil), "func(int8, int32)(0)"},
-	pair{(struct {
-		c func(chan *integer, *int8)
-	}){},
+	pair{struct{ c func(chan *integer, *int8) }{},
 		"struct { c func(chan *reflect_test.integer, *int8) }{func(chan *reflect_test.integer, *int8)(0)}",
 	},
-	pair{(struct {
+	pair{struct {
 		a int8
 		b int32
-	}){},
+	}{},
 		"struct { a int8; b int32 }{0, 0}",
 	},
-	pair{(struct {
+	pair{struct {
 		a int8
 		b int8
 		c int32
-	}){},
+	}{},
 		"struct { a int8; b int8; c int32 }{0, 0, 0}",
 	},
 }

test/bugs/bug299.go → test/fixedbugs/bug299.go

@@ -7,21 +7,21 @@
 package main
 
 type T struct {
-	// accepted by both compilers, legal according to spec
+	// legal according to spec
 	x int
 	y (int)
 	int
 	*float
-	// not accepted by both compilers, not legal according to spec
-	(complex)  // ERROR "non-declaration|expected"
-	(*string)  // ERROR "non-declaration|expected"
-	*(bool)    // ERROR "non-declaration|expected"
+	// not legal according to spec
+	(complex)  // ERROR "non-declaration|expected|parenthesize"
+	(*string)  // ERROR "non-declaration|expected|parenthesize"
+	*(bool)    // ERROR "non-declaration|expected|parenthesize"
 }
 
-// accepted by both compilers, legal according to spec
+// legal according to spec
 func (p T) m() {}
 
-// accepted by 6g, not accepted by gccgo, not legal according to spec
-func (p (T)) f() {}   // ERROR "expected"
-func (p *(T)) g() {}  // ERROR "expected"
-func (p (*T)) h() {}  // ERROR "expected"
+// not legal according to spec
+func (p (T)) f() {}   // ERROR "parenthesize"
+func (p *(T)) g() {}  // ERROR "parenthesize"
+func (p (*T)) h() {}  // ERROR "parenthesize"

test/bugs/bug300.go → test/fixedbugs/bug300.go

@@ -20,10 +20,10 @@ func main() {
 	_ = T{}
 
 	// illegal composite literals: parentheses not allowed around literal type
-	_ = (struct{}){}	// ERROR "xxx"
-	_ = ([42]int){}		// ERROR "xxx"
-	_ = ([...]int){}	// ERROR "xxx"
-	_ = ([]int){}		// ERROR "xxx"
-	_ = (map[int]int){}	// ERROR "xxx"
-	_ = (T){}		// ERROR "xxx"
+	_ = (struct{}){}    // ERROR "parenthesize"
+	_ = ([42]int){}     // ERROR "parenthesize"
+	_ = ([...]int){}    // ERROR "parenthesize"
+	_ = ([]int){}       // ERROR "parenthesize"
+	_ = (map[int]int){} // ERROR "parenthesize"
+	_ = (T){}           // ERROR "parenthesize"
 }

test/golden.out

@@ -177,15 +177,3 @@ panic PC=xxx
 =========== bugs/bug260.go
 FAIL
 BUG: bug260 failed
-
-=========== bugs/bug299.go
-BUG: errchk: bugs/bug299.go:25: missing expected error: 'expected'
-errchk: bugs/bug299.go:26: missing expected error: 'expected'
-errchk: bugs/bug299.go:27: missing expected error: 'expected'
-errchk: bugs/bug299.go: unmatched error messages:
-==================================================
-bugs/bug299.go:19: syntax error: unexpected }
-==================================================
-
-=========== bugs/bug300.go
-BUG: errchk: command succeeded unexpectedly