Commit 4b536c1e authored by Russ Cox's avatar Russ Cox

test for and fix bug involving reflect v.Interface() and ==.

R=r
DELTA=156  (149 added, 2 deleted, 5 changed)
OCL=26973
CL=26973
parent 8f628f49
...@@ -459,6 +459,8 @@ ifacehash(Iface a) ...@@ -459,6 +459,8 @@ ifacehash(Iface a)
// calling nohash will throw too, // calling nohash will throw too,
// but we can print a better error. // but we can print a better error.
printf("hash of unhashable type %s\n", sigt->name); printf("hash of unhashable type %s\n", sigt->name);
if(alg == AFAKE)
throw("fake interface hash");
throw("interface hash"); throw("interface hash");
} }
if(wid <= sizeof(a.data)) if(wid <= sizeof(a.data))
...@@ -502,6 +504,8 @@ ifaceeq(Iface i1, Iface i2) ...@@ -502,6 +504,8 @@ ifaceeq(Iface i1, Iface i2)
// calling noequal will throw too, // calling noequal will throw too,
// but we can print a better error. // but we can print a better error.
printf("comparing uncomparable type %s\n", i1.type->sigt->name); printf("comparing uncomparable type %s\n", i1.type->sigt->name);
if(alg == AFAKE)
throw("fake interface compare");
throw("interface compare"); throw("interface compare");
} }
...@@ -594,16 +598,18 @@ extern int32 ngotypesigs; ...@@ -594,16 +598,18 @@ extern int32 ngotypesigs;
// vv.Interface() returns the result of sys.Unreflect with // vv.Interface() returns the result of sys.Unreflect with
// a typestring of "[]int". If []int is not used with interfaces // a typestring of "[]int". If []int is not used with interfaces
// in the rest of the program, there will be no signature in gotypesigs // in the rest of the program, there will be no signature in gotypesigs
// for "[]int", so we have to invent one. The only requirements // for "[]int", so we have to invent one. The requirements
// on the fake signature are: // on the fake signature are:
// //
// (1) any interface conversion using the signature will fail // (1) any interface conversion using the signature will fail
// (2) calling sys.Reflect() returns the args to unreflect // (2) calling sys.Reflect() returns the args to unreflect
// (3) the right algorithm type is used, for == and map insertion
// //
// (1) is ensured by the fact that we allocate a new Sigt, // (1) is ensured by the fact that we allocate a new Sigt,
// so it will necessarily be != any Sigt in gotypesigs. // so it will necessarily be != any Sigt in gotypesigs.
// (2) is ensured by storing the type string in the signature // (2) is ensured by storing the type string in the signature
// and setting the width to force the correct value of the bool indir. // and setting the width to force the correct value of the bool indir.
// (3) is ensured by sniffing the type string.
// //
// Note that (1) is correct behavior: if the program had tested // Note that (1) is correct behavior: if the program had tested
// for .([]int) instead of .(string) above, then there would be a // for .([]int) instead of .(string) above, then there would be a
...@@ -613,6 +619,47 @@ extern int32 ngotypesigs; ...@@ -613,6 +619,47 @@ extern int32 ngotypesigs;
static Sigt* fake[1009]; static Sigt* fake[1009];
static int32 nfake; static int32 nfake;
enum
{
SizeofInt = 4,
SizeofFloat = 4,
};
// Table of prefixes of names of comparable types.
static struct {
int8 *s;
int8 n;
int8 alg;
int8 w;
} cmp[] =
{
// basic types
"int", 3+1, AMEM, SizeofInt, // +1 is NUL
"uint", 4+1, AMEM, SizeofInt,
"int8", 4+1, AMEM, 1,
"uint8", 5+1, AMEM, 1,
"int16", 5+1, AMEM, 2,
"uint16", 6+1, AMEM, 2,
"int32", 5+1, AMEM, 4,
"uint32", 6+1, AMEM, 4,
"int64", 5+1, AMEM, 8,
"uint64", 6+1, AMEM, 8,
"uintptr", 7+1, AMEM, sizeof(uintptr),
"float", 5+1, AMEM, SizeofFloat,
"float32", 7+1, AMEM, 4,
"float64", 7+1, AMEM, 8,
"bool", 4+1, AMEM, sizeof(bool),
// string compare is special
"string", 6+1, ASTRING, sizeof(string),
// generic types, identified by prefix
"*", 1, AMEM, sizeof(uintptr),
"chan ", 5, AMEM, sizeof(uintptr),
"func(", 5, AMEM, sizeof(uintptr),
"map[", 4, AMEM, sizeof(uintptr),
};
static Sigt* static Sigt*
fakesigt(string type, bool indir) fakesigt(string type, bool indir)
{ {
...@@ -648,10 +695,22 @@ fakesigt(string type, bool indir) ...@@ -648,10 +695,22 @@ fakesigt(string type, bool indir)
sigt = mal(sizeof(*sigt)); sigt = mal(sizeof(*sigt));
sigt->name = mal(type->len + 1); sigt->name = mal(type->len + 1);
mcpy(sigt->name, type->str, type->len); mcpy(sigt->name, type->str, type->len);
sigt->alg = AFAKE; sigt->alg = AFAKE;
sigt->width = 1; // small width sigt->width = 1; // small width
if(indir) if(indir)
sigt->width = 2*sizeof(niliface.data); // big width sigt->width = 2*sizeof(niliface.data); // big width
// AFAKE is like ANOEQ; check whether the type
// should have a more capable algorithm.
for(i=0; i<nelem(cmp); i++) {
if(mcmp((byte*)sigt->name, (byte*)cmp[i].s, cmp[i].n) == 0) {
sigt->alg = cmp[i].alg;
sigt->width = cmp[i].w;
break;
}
}
sigt->link = fake[h]; sigt->link = fake[h];
fake[h] = sigt; fake[h] = sigt;
......
...@@ -29,7 +29,7 @@ sys·panicl(int32 lno) ...@@ -29,7 +29,7 @@ sys·panicl(int32 lno)
} }
panicking++; panicking++;
printf("\npanic PC=%X [%d]\n", (uint64)(uintptr)&lno, panicking); printf("\npanic PC=%X\n", (uint64)(uintptr)&lno);
sp = (uint8*)&lno; sp = (uint8*)&lno;
if(gotraceback()){ if(gotraceback()){
traceback(sys·getcallerpc(&lno), sp, g); traceback(sys·getcallerpc(&lno), sp, g);
...@@ -54,12 +54,10 @@ sys·throwreturn(void) ...@@ -54,12 +54,10 @@ sys·throwreturn(void)
void void
throw(int8 *s) throw(int8 *s)
{ {
prints("throw: "); printf("throw: %s\n", s);
prints(s);
prints("\n");
sys·panicl(-1); sys·panicl(-1);
*(int32*)0 = 0; *(int32*)0 = 0; // not reached
sys_Exit(1); sys_Exit(1); // even more not reached
} }
void void
......
// $G $D/$F.go && $L $F.$A && ./$A.out
// Copyright 2009 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.
package main
import "reflect"
type T struct {
f float32;
g float32;
s string;
t string;
u uint32;
v uint32;
w uint32;
x uint32;
y uint32;
z uint32;
}
func add(s, t string) string {
return s + t;
}
func assert(b bool) {
if !b {
panic("assert");
}
}
func main() {
var x T;
x.f = 1.0;
x.g = x.f;
x.s = add("abc", "def");
x.t = add("abc", "def");
x.u = 1;
x.v = 2;
x.w = 1<<28;
x.x = 2<<28;
x.y = 0x12345678;
x.z = x.y;
// check mem and string
v := reflect.NewValue(x);
i := v.(reflect.StructValue).Field(0);
j := v.(reflect.StructValue).Field(1);
assert(i.Interface() == j.Interface());
s := v.(reflect.StructValue).Field(2);
t := v.(reflect.StructValue).Field(3);
assert(s.Interface() == t.Interface());
// make sure different values are different.
// make sure whole word is being compared,
// not just a single byte.
i = v.(reflect.StructValue).Field(4);
j = v.(reflect.StructValue).Field(5);
assert(i.Interface() != j.Interface());
i = v.(reflect.StructValue).Field(6);
j = v.(reflect.StructValue).Field(7);
assert(i.Interface() != j.Interface());
i = v.(reflect.StructValue).Field(8);
j = v.(reflect.StructValue).Field(9);
assert(i.Interface() == j.Interface());
}
/*
comparing uncomparable type float32
throw: interface compare
panic PC=0x28ceb8 [1]
throw+0x41 /Users/rsc/goX/src/runtime/runtime.c:54
throw(0x3014a, 0x0)
ifaceeq+0x15c /Users/rsc/goX/src/runtime/iface.c:501
ifaceeq(0x2aa7c0, 0x0, 0x0, 0x0, 0x2aa7c0, ...)
sys·ifaceeq+0x48 /Users/rsc/goX/src/runtime/iface.c:527
sys·ifaceeq(0x2aa7c0, 0x0, 0x0, 0x0, 0x2aa7c0, ...)
main·main+0x190 /Users/rsc/goX/src/cmd/gc/x.go:10
main·main()
mainstart+0xf /Users/rsc/goX/src/runtime/amd64/asm.s:53
mainstart()
sys·Goexit /Users/rsc/goX/src/runtime/proc.c:124
sys·Goexit()
*/
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