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#
#
# The Nimrod Compiler
# (c) Copyright 2014 Andreas Rumpf
#
# See the file "copying.txt", included in this
# distribution, for details about the copyright.
#
# This module does the instantiation of generic types.
import ast, astalgo, msgs, types, magicsys, semdata, renderer
const
tfInstClearedFlags = {tfHasMeta}
proc sharedPtrCheck(info: TLineInfo, t: PType) =
if t.kind == tyPtr and t.len > 1:
if t.sons[0].sym.magic in {mShared, mGuarded}:
incl(t.flags, tfShared)
if t.sons[0].sym.magic == mGuarded: incl(t.flags, tfGuarded)
if tfHasGCedMem in t.flags or t.isGCedMem:
localError(info, errGenerated,
"shared memory may not refer to GC'ed thread local memory")
proc checkPartialConstructedType(info: TLineInfo, t: PType) =
if tfAcyclic in t.flags and skipTypes(t, abstractInst).kind != tyObject:
localError(info, errInvalidPragmaX, "acyclic")
elif t.kind == tyVar and t.sons[0].kind == tyVar:
localError(info, errVarVarTypeNotAllowed)
else:
sharedPtrCheck(info, t)
proc checkConstructedType*(info: TLineInfo, typ: PType) =
var t = typ.skipTypes({tyDistinct})
if t.kind in tyTypeClasses: discard
elif tfAcyclic in t.flags and skipTypes(t, abstractInst).kind != tyObject:
localError(info, errInvalidPragmaX, "acyclic")
elif t.kind == tyVar and t.sons[0].kind == tyVar:
localError(info, errVarVarTypeNotAllowed)
elif computeSize(t) == szIllegalRecursion:
localError(info, errIllegalRecursionInTypeX, typeToString(t))
else:
sharedPtrCheck(info, t)
when false:
if t.kind == tyObject and t.sons[0] != nil:
if t.sons[0].kind != tyObject or tfFinal in t.sons[0].flags:
localError(info, errInheritanceOnlyWithNonFinalObjects)
proc searchInstTypes*(key: PType): PType =
let genericTyp = key.sons[0]
internalAssert genericTyp.kind == tyGenericBody and
key.sons[0] == genericTyp and
genericTyp.sym != nil
if genericTyp.sym.typeInstCache == nil:
return
for inst in genericTyp.sym.typeInstCache:
if inst.id == key.id: return inst
if inst.sons.len < key.sons.len:
# XXX: This happens for prematurely cached
# types such as TChannel[empty]. Why?
# See the notes for PActor in handleGenericInvokation
return
block matchType:
for j in 1 .. high(key.sons):
# XXX sameType is not really correct for nested generics?
if not compareTypes(inst.sons[j], key.sons[j],
flags = {ExactGenericParams}):
break matchType
return inst
proc cacheTypeInst*(inst: PType) =
# XXX: add to module's generics
# update the refcount
let genericTyp = inst.sons[0]
genericTyp.sym.typeInstCache.safeAdd(inst)
type
TReplTypeVars* {.final.} = object
c*: PContext
typeMap*: TIdTable # map PType to PType
symMap*: TIdTable # map PSym to PSym
localCache*: TIdTable # local cache for remembering alraedy replaced
# types during instantiation of meta types
# (they are not stored in the global cache)
info*: TLineInfo
allowMetaTypes*: bool # allow types such as seq[Number]
# i.e. the result contains unresolved generics
proc replaceTypeVarsTAux(cl: var TReplTypeVars, t: PType): PType
proc replaceTypeVarsS(cl: var TReplTypeVars, s: PSym): PSym
proc replaceTypeVarsN*(cl: var TReplTypeVars, n: PNode): PNode
template checkMetaInvariants(cl: TReplTypeVars, t: PType) =
when false:
if t != nil and tfHasMeta in t.flags and
cl.allowMetaTypes == false:
echo "UNEXPECTED META ", t.id, " ", instantiationInfo(-1)
debug t
writeStackTrace()
quit 1
proc replaceTypeVarsT*(cl: var TReplTypeVars, t: PType): PType =
result = replaceTypeVarsTAux(cl, t)
checkMetaInvariants(cl, result)
proc prepareNode(cl: var TReplTypeVars, n: PNode): PNode =
let t = replaceTypeVarsT(cl, n.typ)
if t != nil and t.kind == tyStatic and t.n != nil:
return t.n
result = copyNode(n)
result.typ = t
if result.kind == nkSym: result.sym = replaceTypeVarsS(cl, n.sym)
let isCall = result.kind in nkCallKinds
for i in 0 .. <n.safeLen:
# XXX HACK: ``f(a, b)``, avoid to instantiate `f`
if isCall and i == 0: result.add(n[i])
else: result.add(prepareNode(cl, n[i]))
proc isTypeParam(n: PNode): bool =
# XXX: generic params should use skGenericParam instead of skType
return n.kind == nkSym and
(n.sym.kind == skGenericParam or
(n.sym.kind == skType and sfFromGeneric in n.sym.flags))
proc hasGenericArguments*(n: PNode): bool =
if n.kind == nkSym:
return n.sym.kind == skGenericParam or
(n.sym.kind == skType and
n.sym.typ.flags * {tfGenericTypeParam, tfImplicitTypeParam} != {})
else:
for i in 0.. <n.safeLen:
if hasGenericArguments(n.sons[i]): return true
return false
proc reResolveCallsWithTypedescParams(cl: var TReplTypeVars, n: PNode): PNode =
# This is needed fo tgenericshardcases
# It's possible that a generic param will be used in a proc call to a
# typedesc accepting proc. After generic param substitution, such procs
# should be optionally instantiated with the correct type. In order to
# perform this instantiation, we need to re-run the generateInstance path
# in the compiler, but it's quite complicated to do so at the moment so we
# resort to a mild hack; the head symbol of the call is temporary reset and
# overload resolution is executed again (which may trigger generateInstance).
if n.kind in nkCallKinds and sfFromGeneric in n[0].sym.flags:
var needsFixing = false
for i in 1 .. <n.safeLen:
if isTypeParam(n[i]): needsFixing = true
if needsFixing:
n.sons[0] = newSymNode(n.sons[0].sym.owner)
return cl.c.semOverloadedCall(cl.c, n, n, {skProc})
for i in 0 .. <n.safeLen:
n.sons[i] = reResolveCallsWithTypedescParams(cl, n[i])
return n
proc replaceTypeVarsN(cl: var TReplTypeVars, n: PNode): PNode =
if n == nil: return
result = copyNode(n)
if n.typ != nil:
result.typ = replaceTypeVarsT(cl, n.typ)
checkMetaInvariants(cl, result.typ)
case n.kind
of nkNone..pred(nkSym), succ(nkSym)..nkNilLit:
discard
of nkSym:
result.sym = replaceTypeVarsS(cl, n.sym)
if result.sym.typ.kind == tyEmpty:
# don't add the 'void' field
result = newNode(nkRecList, n.info)
of nkRecWhen:
var branch: PNode = nil # the branch to take
for i in countup(0, sonsLen(n) - 1):
var it = n.sons[i]
if it == nil: illFormedAst(n)
case it.kind
of nkElifBranch:
checkSonsLen(it, 2)
var cond = prepareNode(cl, it.sons[0])
var e = cl.c.semConstExpr(cl.c, cond)
if e.kind != nkIntLit:
internalError(e.info, "ReplaceTypeVarsN: when condition not a bool")
if e.intVal != 0 and branch == nil: branch = it.sons[1]
of nkElse:
checkSonsLen(it, 1)
if branch == nil: branch = it.sons[0]
else: illFormedAst(n)
if branch != nil:
result = replaceTypeVarsN(cl, branch)
else:
result = newNodeI(nkRecList, n.info)
of nkStaticExpr:
var n = prepareNode(cl, n)
n = reResolveCallsWithTypedescParams(cl, n)
result = if cl.allowMetaTypes: n
else: cl.c.semExpr(cl.c, n)
else:
var length = sonsLen(n)
if length > 0:
newSons(result, length)
for i in countup(0, length - 1):
result.sons[i] = replaceTypeVarsN(cl, n.sons[i])
proc replaceTypeVarsS(cl: var TReplTypeVars, s: PSym): PSym =
if s == nil: return nil
result = PSym(idTableGet(cl.symMap, s))
if result == nil:
result = copySym(s, false)
incl(result.flags, sfFromGeneric)
idTablePut(cl.symMap, s, result)
result.owner = s.owner
result.typ = replaceTypeVarsT(cl, s.typ)
result.ast = replaceTypeVarsN(cl, s.ast)
proc lookupTypeVar(cl: TReplTypeVars, t: PType): PType =
result = PType(idTableGet(cl.typeMap, t))
if result == nil:
if cl.allowMetaTypes or tfRetType in t.flags: return
localError(t.sym.info, errCannotInstantiateX, typeToString(t))
result = errorType(cl.c)
elif result.kind == tyGenericParam and not cl.allowMetaTypes:
internalError(cl.info, "substitution with generic parameter")
proc instCopyType*(cl: var TReplTypeVars, t: PType): PType =
# XXX: relying on allowMetaTypes is a kludge
result = copyType(t, t.owner, cl.allowMetaTypes)
result.flags.incl tfFromGeneric
result.flags.excl tfInstClearedFlags
proc handleGenericInvokation(cl: var TReplTypeVars, t: PType): PType =
# tyGenericInvokation[A, tyGenericInvokation[A, B]]
# is difficult to handle:
var body = t.sons[0]
if body.kind != tyGenericBody: internalError(cl.info, "no generic body")
var header: PType = t
# search for some instantiation here:
if cl.allowMetaTypes:
result = PType(idTableGet(cl.localCache, t))
else:
result = searchInstTypes(t)
if result != nil: return
for i in countup(1, sonsLen(t) - 1):
var x = t.sons[i]
if x.kind == tyGenericParam:
x = lookupTypeVar(cl, x)
if x != nil:
if header == t: header = instCopyType(cl, t)
header.sons[i] = x
propagateToOwner(header, x)
else:
propagateToOwner(header, x)
if header != t:
# search again after first pass:
result = searchInstTypes(header)
if result != nil: return
else:
header = instCopyType(cl, t)
result = newType(tyGenericInst, t.sons[0].owner)
result.flags = header.flags
# be careful not to propagate unnecessary flags here (don't use rawAddSon)
result.sons = @[header.sons[0]]
# ugh need another pass for deeply recursive generic types (e.g. PActor)
# we need to add the candidate here, before it's fully instantiated for
# recursive instantions:
if not cl.allowMetaTypes:
cacheTypeInst(result)
else:
idTablePut(cl.localCache, t, result)
for i in countup(1, sonsLen(t) - 1):
var x = replaceTypeVarsT(cl, t.sons[i])
assert x.kind != tyGenericInvokation
header.sons[i] = x
propagateToOwner(header, x)
idTablePut(cl.typeMap, body.sons[i-1], x)
for i in countup(1, sonsLen(t) - 1):
# if one of the params is not concrete, we cannot do anything
# but we already raised an error!
rawAddSon(result, header.sons[i])
var newbody = replaceTypeVarsT(cl, lastSon(body))
newbody.flags = newbody.flags + (t.flags + body.flags - tfInstClearedFlags)
result.flags = result.flags + newbody.flags
newbody.callConv = body.callConv
# This type may be a generic alias and we want to resolve it here.
# One step is enough, because the recursive nature of
# handleGenericInvokation will handle the alias-to-alias-to-alias case
if newbody.isGenericAlias: newbody = newbody.skipGenericAlias
rawAddSon(result, newbody)
checkPartialConstructedType(cl.info, newbody)
proc eraseVoidParams*(t: PType) =
if t.sons[0] != nil and t.sons[0].kind == tyEmpty:
t.sons[0] = nil
for i in 1 .. <t.sonsLen:
# don't touch any memory unless necessary
if t.sons[i].kind == tyEmpty:
var pos = i
for j in i+1 .. <t.sonsLen:
if t.sons[j].kind != tyEmpty:
t.sons[pos] = t.sons[j]
t.n.sons[pos] = t.n.sons[j]
inc pos
setLen t.sons, pos
setLen t.n.sons, pos
return
proc skipIntLiteralParams*(t: PType) =
for i in 0 .. <t.sonsLen:
let p = t.sons[i]
if p == nil: continue
let skipped = p.skipIntLit
if skipped != p:
t.sons[i] = skipped
if i > 0: t.n.sons[i].sym.typ = skipped
# when the typeof operator is used on a static input
# param, the results gets infected with static as well:
if t.sons[0] != nil and t.sons[0].kind == tyStatic:
t.sons[0] = t.sons[0].base
proc propagateFieldFlags(t: PType, n: PNode) =
# This is meant for objects and tuples
# The type must be fully instantiated!
internalAssert n.kind != nkRecWhen
case n.kind
of nkSym:
propagateToOwner(t, n.sym.typ)
of nkRecList, nkRecCase, nkOfBranch, nkElse:
for son in n:
propagateFieldFlags(t, son)
else: discard
proc replaceTypeVarsTAux(cl: var TReplTypeVars, t: PType): PType =
result = t
if t == nil: return
if t.kind in {tyStatic, tyGenericParam, tyIter} + tyTypeClasses:
let lookup = PType(idTableGet(cl.typeMap, t))
if lookup != nil: return lookup
case t.kind
of tyGenericInvokation:
result = handleGenericInvokation(cl, t)
of tyGenericBody:
localError(cl.info, errCannotInstantiateX, typeToString(t))
result = t
#result = replaceTypeVarsT(cl, lastSon(t))
of tyFromExpr:
if cl.allowMetaTypes: return
var n = prepareNode(cl, t.n)
n = cl.c.semConstExpr(cl.c, n)
if n.typ.kind == tyTypeDesc:
# XXX: sometimes, chained typedescs enter here.
# It may be worth investigating why this is happening,
# because it may cause other bugs elsewhere.
result = n.typ.skipTypes({tyTypeDesc})
# result = n.typ.base
else:
if n.typ.kind != tyStatic:
# XXX: In the future, semConstExpr should
# return tyStatic values to let anyone make
# use of this knowledge. The patching here
# won't be necessary then.
result = newTypeS(tyStatic, cl.c)
result.sons = @[n.typ]
result.n = n
else:
result = n.typ
of tyInt:
result = skipIntLit(t)
# XXX now there are also float literals
of tyTypeDesc:
let lookup = PType(idTableGet(cl.typeMap, t)) # lookupTypeVar(cl, t)
if lookup != nil:
result = lookup
if tfUnresolved in t.flags: result = result.base
elif t.sons[0].kind != tyNone:
result = makeTypeDesc(cl.c, replaceTypeVarsT(cl, t.sons[0]))
of tyUserTypeClass:
result = t
of tyGenericInst:
result = instCopyType(cl, t)
for i in 1 .. <result.sonsLen:
result.sons[i] = replaceTypeVarsT(cl, result.sons[i])
propagateToOwner(result, result.lastSon)
else:
if containsGenericType(t):
result = instCopyType(cl, t)
result.size = -1 # needs to be recomputed
for i in countup(0, sonsLen(result) - 1):
if result.sons[i] != nil:
result.sons[i] = replaceTypeVarsT(cl, result.sons[i])
propagateToOwner(result, result.sons[i])
result.n = replaceTypeVarsN(cl, result.n)
case result.kind
of tyArray:
let idx = result.sons[0]
internalAssert idx.kind != tyStatic
of tyObject, tyTuple:
propagateFieldFlags(result, result.n)
of tyProc:
eraseVoidParams(result)
skipIntLiteralParams(result)
else: discard
proc initTypeVars*(p: PContext, pt: TIdTable, info: TLineInfo): TReplTypeVars =
initIdTable(result.symMap)
copyIdTable(result.typeMap, pt)
initIdTable(result.localCache)
result.info = info
result.c = p
proc replaceTypesInBody*(p: PContext, pt: TIdTable, n: PNode): PNode =
var cl = initTypeVars(p, pt, n.info)
pushInfoContext(n.info)
result = replaceTypeVarsN(cl, n)
popInfoContext()
proc generateTypeInstance*(p: PContext, pt: TIdTable, info: TLineInfo,
t: PType): PType =
var cl = initTypeVars(p, pt, info)
pushInfoContext(info)
result = replaceTypeVarsT(cl, t)
popInfoContext()
template generateTypeInstance*(p: PContext, pt: TIdTable, arg: PNode,
t: PType): expr =
generateTypeInstance(p, pt, arg.info, t)
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