jyapayne/Nim
1
0
Fork 0
Code Issues Pull requests Projects Releases Packages Wiki Activity Actions

got rid of unsound co/contravariance in procvars

Browse source
This commit is contained in:
Araq 2011-06-17 01:04:33 +02:00
commit 849208d779
6 changed files with 122 additions and 56 deletions
Download patch file Download diff file Expand all files Collapse all files

67
compiler/sigmatch.nim
View file

@ -189,6 +189,39 @@ proc constraintRel(mapping: var TIdTable, f, a: PType): TTypeRelation =
result = isNone
if f.kind == a.kind: result = isGeneric
proc procTypeRel(mapping: var TIdTable, f, a: PType): TTypeRelation =
proc inconsistentVarTypes(f, a: PType): bool {.inline.} =
result = f.kind != a.kind and (f.kind == tyVar or a.kind == tyVar)
case a.kind
of tyNil: result = isSubtype
of tyProc:
if sonsLen(f) != sonsLen(a) or f.callconv != a.callconv: return
# Note: We have to do unification for the parameters before the
# return type!
result = isEqual # start with maximum; also correct for no
# params at all
for i in countup(1, sonsLen(f)-1):
var m = typeRel(mapping, f.sons[i], a.sons[i])
if m <= isSubtype or inconsistentVarTypes(f.sons[i], a.sons[i]):
return isNone
else: result = minRel(m, result)
if f.sons[0] != nil:
if a.sons[0] != nil:
var m = typeRel(mapping, f.sons[0], a.sons[0])
# Subtype is sufficient for return types!
if m < isSubtype or inconsistentVarTypes(f.sons[0], a.sons[0]):
result = isNone
elif m == isSubtype: result = isConvertible
else: result = minRel(m, result)
else:
result = isNone
elif a.sons[0] != nil:
result = isNone
if tfNoSideEffect in f.flags and tfNoSideEffect notin a.flags:
result = isNone
else: nil
proc typeRel(mapping: var TIdTable, f, a: PType): TTypeRelation =
# is a subtype of f?
result = isNone
@ -316,39 +349,7 @@ proc typeRel(mapping: var TIdTable, f, a: PType): TTypeRelation =
of tyNil: result = isSubtype
else: nil
of tyProc:
case a.kind
of tyNil: result = isSubtype
of tyProc:
if (sonsLen(f) == sonsLen(a)) and (f.callconv == a.callconv):
# Note: We have to do unification for the parameters before the
# return type!
result = isEqual # start with maximum; also correct for no
# params at all
var m: TTypeRelation
for i in countup(1, sonsLen(f) - 1):
m = typeRel(mapping, f.sons[i], a.sons[i])
if (m == isNone) and
(typeRel(mapping, a.sons[i], f.sons[i]) == isSubtype):
# allow ``f.son`` as subtype of ``a.son``!
result = isConvertible
elif m < isSubtype:
return isNone
else:
result = minRel(m, result)
if f.sons[0] != nil:
if a.sons[0] != nil:
m = typeRel(mapping, f.sons[0], a.sons[0])
# Subtype is sufficient for return types!
if m < isSubtype: result = isNone
elif m == isSubtype: result = isConvertible
else: result = minRel(m, result)
else:
result = isNone
elif a.sons[0] != nil:
result = isNone
if (tfNoSideEffect in f.flags) and not (tfNoSideEffect in a.flags):
result = isNone
else: nil
result = procTypeRel(mapping, f, a)
of tyPointer:
case a.kind
of tyPointer: result = isEqual