Commit 71b3b460 authored by Rémy Oudompheng's avatar Rémy Oudompheng

cmd/gc: accept cases with same value but different types in switch.

Fixes #4781.

R=golang-dev, rsc
CC=golang-dev
https://golang.org/cl/7365056
parent 9e66ee45
......@@ -117,12 +117,15 @@ exprcmp(Case *c1, Case *c2)
n1 = c1->node->left;
n2 = c2->node->left;
// sort by type (for switches on interface)
ct = n1->val.ctype;
if(ct != n2->val.ctype) {
// invalid program, but return a sort
// order so that we can give a better
// error later.
if(ct != n2->val.ctype)
return ct - n2->val.ctype;
if(!eqtype(n1->type, n2->type)) {
if(n1->type->vargen > n2->type->vargen)
return +1;
else
return -1;
}
// sort by constant value
......@@ -379,6 +382,7 @@ mkcaselist(Node *sw, int arg)
case Strue:
case Sfalse:
c->type = Texprvar;
c->hash = typehash(n->left->type);
switch(consttype(n->left)) {
case CTFLT:
case CTINT:
......
......@@ -305,6 +305,35 @@ func main() {
assert(false, "i should be true")
}
// switch on interface with constant cases differing by type.
// was rejected by compiler: see issue 4781
type T int
type B bool
type F float64
type S string
switch i := interface{}(float64(1.0)); i {
case nil:
assert(false, "i should be float64(1.0)")
case (*int)(nil):
assert(false, "i should be float64(1.0)")
case 1:
assert(false, "i should be float64(1.0)")
case T(1):
assert(false, "i should be float64(1.0)")
case F(1.0):
assert(false, "i should be float64(1.0)")
case 1.0:
assert(true, "true")
case "hello":
assert(false, "i should be float64(1.0)")
case S("hello"):
assert(false, "i should be float64(1.0)")
case true, B(false):
assert(false, "i should be float64(1.0)")
case false, B(true):
assert(false, "i should be float64(1.0)")
}
// switch on array.
switch ar := [3]int{1, 2, 3}; ar {
case [3]int{1, 2, 3}:
......
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