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fixes #4673

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This commit is contained in:
Andreas Rumpf 2016-09-01 13:01:22 +02:00
commit 3a13706d7d
19 changed files with 74 additions and 31 deletions
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25
compiler/sigmatch.nim
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@ -352,18 +352,28 @@ proc handleFloatRange(f, a: PType): TTypeRelation =
else: result = isIntConv
else: result = isNone
proc isObjectSubtype(a, f: PType): int =
proc isObjectSubtype(c: var TCandidate; a, f, fGenericOrigin: PType): int =
var t = a
assert t.kind == tyObject
var depth = 0
var last = a
while t != nil and not sameObjectTypes(f, t):
assert t.kind == tyObject
t = t.sons[0]
if t == nil: break
t = skipTypes(t, {tyGenericInst})
last = t
t = skipTypes(t, skipPtrs)
inc depth
if t != nil:
if fGenericOrigin != nil and last.kind == tyGenericInst and
last.len-1 == fGenericOrigin.len:
for i in countup(1, sonsLen(fGenericOrigin) - 1):
let x = PType(idTableGet(c.bindings, fGenericOrigin.sons[i]))
if x == nil:
put(c, fGenericOrigin.sons[i], last.sons[i])
result = depth
else:
result = -1
type
SkippedPtr = enum skippedNone, skippedRef, skippedPtr
@ -896,7 +906,7 @@ proc typeRel(c: var TCandidate, f, aOrig: PType, doBind = true): TTypeRelation =
result = isEqual
# elif tfHasMeta in f.flags: result = recordRel(c, f, a)
else:
var depth = isObjectSubtype(a, f)
var depth = isObjectSubtype(c, a, f, nil)
if depth > 0:
inc(c.inheritancePenalty, depth)
result = isSubtype
@ -1012,6 +1022,15 @@ proc typeRel(c: var TCandidate, f, aOrig: PType, doBind = true): TTypeRelation =
result = isGeneric
else:
let genericBody = f.sons[0]
var askip = skippedNone
var fskip = skippedNone
let aobj = x.skipToObject(askip)
let fobj = genericBody.lastSon.skipToObject(fskip)
if fobj != nil and aobj != nil and askip == fskip:
let depth = isObjectSubtype(c, aobj, fobj, f)
if depth >= 0:
c.inheritancePenalty += depth
return if depth == 0: isGeneric else: isSubtype
result = typeRel(c, genericBody, x)
if result != isNone:
# see tests/generics/tgeneric3.nim for an example that triggers this