mirror of
https://github.com/golang/go
synced 2024-09-05 07:54:46 +00:00
gc: detect type switch variable not used cases.
Fixes #873 Fixes #2162 R=rsc CC=golang-dev https://golang.org/cl/5341043
This commit is contained in:
parent
f2dc50b48d
commit
aac144b120
|
@ -418,9 +418,7 @@ simple_stmt:
|
|||
| expr_list LCOLAS expr_list
|
||||
{
|
||||
if($3->n->op == OTYPESW) {
|
||||
Node *n;
|
||||
|
||||
n = N;
|
||||
$$ = nod(OTYPESW, N, $3->n->right);
|
||||
if($3->next != nil)
|
||||
yyerror("expr.(type) must be alone in list");
|
||||
if($1->next != nil)
|
||||
|
@ -428,8 +426,7 @@ simple_stmt:
|
|||
else if($1->n->op != ONAME && $1->n->op != OTYPE && $1->n->op != ONONAME)
|
||||
yyerror("invalid variable name %N in type switch", $1->n);
|
||||
else
|
||||
n = $1->n;
|
||||
$$ = nod(OTYPESW, n, $3->n->right);
|
||||
$$->left = dclname($1->n->sym); // it's a colas, so must not re-use an oldname.
|
||||
break;
|
||||
}
|
||||
$$ = colas($1, $3);
|
||||
|
@ -448,7 +445,7 @@ simple_stmt:
|
|||
case:
|
||||
LCASE expr_or_type_list ':'
|
||||
{
|
||||
Node *n;
|
||||
Node *n, *nn;
|
||||
|
||||
// will be converted to OCASE
|
||||
// right will point to next case
|
||||
|
@ -458,12 +455,13 @@ case:
|
|||
$$->list = $2;
|
||||
if(typesw != N && typesw->right != N && (n=typesw->right->left) != N) {
|
||||
// type switch - declare variable
|
||||
n = newname(n->sym);
|
||||
n->used = 1; // TODO(rsc): better job here
|
||||
declare(n, dclcontext);
|
||||
$$->nname = n;
|
||||
nn = newname(n->sym);
|
||||
declare(nn, dclcontext);
|
||||
$$->nname = nn;
|
||||
|
||||
// keep track of the instances for reporting unused
|
||||
nn->defn = typesw->right;
|
||||
}
|
||||
break;
|
||||
}
|
||||
| LCASE expr_or_type_list '=' expr ':'
|
||||
{
|
||||
|
@ -494,16 +492,18 @@ case:
|
|||
}
|
||||
| LDEFAULT ':'
|
||||
{
|
||||
Node *n;
|
||||
Node *n, *nn;
|
||||
|
||||
markdcl();
|
||||
$$ = nod(OXCASE, N, N);
|
||||
if(typesw != N && typesw->right != N && (n=typesw->right->left) != N) {
|
||||
// type switch - declare variable
|
||||
n = newname(n->sym);
|
||||
n->used = 1; // TODO(rsc): better job here
|
||||
declare(n, dclcontext);
|
||||
$$->nname = n;
|
||||
nn = newname(n->sym);
|
||||
declare(nn, dclcontext);
|
||||
$$->nname = nn;
|
||||
|
||||
// keep track of the instances for reporting unused
|
||||
nn->defn = typesw->right;
|
||||
}
|
||||
}
|
||||
|
||||
|
|
|
@ -63,7 +63,6 @@ walk(Node *fn)
|
|||
{
|
||||
char s[50];
|
||||
NodeList *l;
|
||||
Node *n;
|
||||
int lno;
|
||||
|
||||
curfn = fn;
|
||||
|
@ -77,15 +76,33 @@ walk(Node *fn)
|
|||
yyerror("function ends without a return statement");
|
||||
|
||||
lno = lineno;
|
||||
|
||||
// Final typecheck for any unused variables.
|
||||
// It's hard to be on the heap when not-used, but best to be consistent about &~PHEAP here and below.
|
||||
for(l=fn->dcl; l; l=l->next)
|
||||
if(l->n->op == ONAME && (l->n->class&~PHEAP) == PAUTO)
|
||||
typecheck(&l->n, Erv | Easgn);
|
||||
|
||||
// Propagate the used flag for typeswitch variables up to the NONAME in it's definition.
|
||||
for(l=fn->dcl; l; l=l->next)
|
||||
if(l->n->op == ONAME && (l->n->class&~PHEAP) == PAUTO && l->n->defn && l->n->defn->op == OTYPESW && l->n->used)
|
||||
l->n->defn->left->used++;
|
||||
|
||||
for(l=fn->dcl; l; l=l->next) {
|
||||
n = l->n;
|
||||
if(n->op != ONAME || n->class != PAUTO)
|
||||
if(l->n->op != ONAME || (l->n->class&~PHEAP) != PAUTO || l->n->sym->name[0] == '&' || l->n->used)
|
||||
continue;
|
||||
lineno = n->lineno;
|
||||
typecheck(&n, Erv | Easgn); // only needed for unused variables
|
||||
if(!n->used && n->sym->name[0] != '&' && !nsyntaxerrors)
|
||||
yyerror("%S declared and not used", n->sym);
|
||||
}
|
||||
if(l->n->defn && l->n->defn->op == OTYPESW) {
|
||||
if(l->n->defn->left->used)
|
||||
continue;
|
||||
lineno = l->n->defn->left->lineno;
|
||||
yyerror("%S declared and not used", l->n->sym);
|
||||
l->n->defn->left->used = 1; // suppress repeats
|
||||
} else {
|
||||
lineno = l->n->lineno;
|
||||
yyerror("%S declared and not used", l->n->sym);
|
||||
}
|
||||
}
|
||||
|
||||
lineno = lno;
|
||||
if(nerrors != 0)
|
||||
return;
|
||||
|
|
|
@ -617,7 +617,7 @@ func (p *Parser) Skip() error {
|
|||
if err != nil {
|
||||
return err
|
||||
}
|
||||
switch t := tok.(type) {
|
||||
switch tok.(type) {
|
||||
case StartElement:
|
||||
if err := p.Skip(); err != nil {
|
||||
return err
|
||||
|
|
|
@ -131,7 +131,7 @@ func (x Const) Match(y Const) (u, v Const) {
|
|||
// otherwise the result is invalid.
|
||||
func (x Const) Convert(typ *Type) Const {
|
||||
// TODO(gri) implement this
|
||||
switch x := x.val.(type) {
|
||||
switch x.val.(type) {
|
||||
case bool:
|
||||
case *big.Int:
|
||||
case *big.Rat:
|
||||
|
|
|
@ -1131,7 +1131,7 @@ func (p *parser) parseLiteralValue(typ ast.Expr) ast.Expr {
|
|||
|
||||
// checkExpr checks that x is an expression (and not a type).
|
||||
func (p *parser) checkExpr(x ast.Expr) ast.Expr {
|
||||
switch t := unparen(x).(type) {
|
||||
switch unparen(x).(type) {
|
||||
case *ast.BadExpr:
|
||||
case *ast.Ident:
|
||||
case *ast.BasicLit:
|
||||
|
|
|
@ -20,7 +20,7 @@ type Getter interface {
|
|||
|
||||
func f1(p Empty) {
|
||||
switch x := p.(type) {
|
||||
default: println("failed to match interface"); os.Exit(1);
|
||||
default: println("failed to match interface", x); os.Exit(1);
|
||||
case Getter: break;
|
||||
}
|
||||
|
||||
|
|
|
@ -12,7 +12,7 @@ func main() {
|
|||
// and worse, compiled the wrong code
|
||||
// for one of them.
|
||||
var x interface{};
|
||||
switch v := x.(type) {
|
||||
switch x.(type) {
|
||||
case func(int):
|
||||
case func(f int): // ERROR "duplicate"
|
||||
}
|
||||
|
|
|
@ -7,7 +7,7 @@
|
|||
package main
|
||||
func main() {
|
||||
var v interface{} = 0;
|
||||
switch x := v.(type) {
|
||||
switch v.(type) {
|
||||
case int:
|
||||
fallthrough; // ERROR "fallthrough"
|
||||
default:
|
||||
|
|
|
@ -80,7 +80,7 @@ func main() {
|
|||
case 2:
|
||||
i = 3.14
|
||||
}
|
||||
switch k := i.(type) {
|
||||
switch i.(type) {
|
||||
case p0.T:
|
||||
if j != 0 {
|
||||
println("type switch p0.T")
|
||||
|
|
|
@ -15,5 +15,7 @@ func foo(t interface{}, c chan int) {
|
|||
case <-c:
|
||||
// bug was: internal compiler error: var without type, init: v
|
||||
}
|
||||
default:
|
||||
_ = v
|
||||
}
|
||||
}
|
||||
|
|
32
test/fixedbugs/bug373.go
Normal file
32
test/fixedbugs/bug373.go
Normal file
|
@ -0,0 +1,32 @@
|
|||
// errchk $G $D/$F.go
|
||||
|
||||
// Copyright 2011 The Go Authors. All rights reserved.
|
||||
// Use of this source code is governed by a BSD-style
|
||||
// license that can be found in the LICENSE file.
|
||||
|
||||
// Issue 873, 2162
|
||||
|
||||
package foo
|
||||
|
||||
func f(x interface{}) {
|
||||
switch t := x.(type) { // ERROR "declared and not used"
|
||||
case int:
|
||||
}
|
||||
}
|
||||
|
||||
func g(x interface{}) {
|
||||
switch t := x.(type) {
|
||||
case int:
|
||||
case float32:
|
||||
println(t)
|
||||
}
|
||||
}
|
||||
|
||||
func h(x interface{}) {
|
||||
switch t := x.(type) {
|
||||
case int:
|
||||
case float32:
|
||||
default:
|
||||
println(t)
|
||||
}
|
||||
}
|
Loading…
Reference in a new issue