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Diffstat (limited to 'compiler/semmagic.nim')
| -rw-r--r-- | compiler/semmagic.nim | 709 |
1 files changed, 709 insertions, 0 deletions
diff --git a/compiler/semmagic.nim b/compiler/semmagic.nim new file mode 100644 index 000000000..a12e933e7 --- /dev/null +++ b/compiler/semmagic.nim @@ -0,0 +1,709 @@ +# +# +# The Nim Compiler +# (c) Copyright 2015 Andreas Rumpf +# +# See the file "copying.txt", included in this +# distribution, for details about the copyright. +# + +# This include file implements the semantic checking for magics. +# included from sem.nim + +proc semObjConstr(c: PContext, n: PNode, flags: TExprFlags; expectedType: PType = nil): PNode + + +proc addDefaultFieldForNew(c: PContext, n: PNode): PNode = + result = n + let typ = result[1].typ # new(x) + if typ.skipTypes({tyGenericInst, tyAlias, tySink}).kind == tyRef and typ.skipTypes({tyGenericInst, tyAlias, tySink})[0].kind == tyObject: + var asgnExpr = newTree(nkObjConstr, newNodeIT(nkType, result[1].info, typ)) + asgnExpr.typ = typ + var t = typ.skipTypes({tyGenericInst, tyAlias, tySink})[0] + while true: + asgnExpr.sons.add defaultFieldsForTheUninitialized(c, t.n, false) + let base = t.baseClass + if base == nil: + break + t = skipTypes(base, skipPtrs) + + if asgnExpr.sons.len > 1: + result = newTree(nkAsgn, result[1], asgnExpr) + +proc semAddr(c: PContext; n: PNode): PNode = + result = newNodeI(nkAddr, n.info) + let x = semExprWithType(c, n) + if x.kind == nkSym: + x.sym.flags.incl(sfAddrTaken) + if isAssignable(c, x) notin {arLValue, arLocalLValue, arAddressableConst, arLentValue}: + localError(c.config, n.info, errExprHasNoAddress) + result.add x + result.typ = makePtrType(c, x.typ) + +proc semTypeOf(c: PContext; n: PNode): PNode = + var m = BiggestInt 1 # typeOfIter + if n.len == 3: + let mode = semConstExpr(c, n[2]) + if mode.kind != nkIntLit: + localError(c.config, n.info, "typeof: cannot evaluate 'mode' parameter at compile-time") + else: + m = mode.intVal + result = newNodeI(nkTypeOfExpr, n.info) + inc c.inTypeofContext + defer: dec c.inTypeofContext # compiles can raise an exception + let typExpr = semExprWithType(c, n[1], if m == 1: {efInTypeof} else: {}) + result.add typExpr + if typExpr.typ.kind == tyFromExpr: + typExpr.typ.flags.incl tfNonConstExpr + result.typ = makeTypeDesc(c, typExpr.typ) + +type + SemAsgnMode = enum asgnNormal, noOverloadedSubscript, noOverloadedAsgn + +proc semAsgn(c: PContext, n: PNode; mode=asgnNormal): PNode +proc semSubscript(c: PContext, n: PNode, flags: TExprFlags): PNode + +proc semArrGet(c: PContext; n: PNode; flags: TExprFlags): PNode = + result = newNodeI(nkBracketExpr, n.info) + for i in 1..<n.len: result.add(n[i]) + result = semSubscript(c, result, flags) + if result.isNil: + let x = copyTree(n) + x[0] = newIdentNode(getIdent(c.cache, "[]"), n.info) + if c.inGenericContext > 0: + for i in 0..<n.len: + let a = n[i] + if a.typ != nil and a.typ.kind in {tyGenericParam, tyFromExpr}: + # expression is compiled early in a generic body + result = semGenericStmt(c, x) + result.typ = makeTypeFromExpr(c, copyTree(result)) + result.typ.flags.incl tfNonConstExpr + return + bracketNotFoundError(c, x, flags) + #localError(c.config, n.info, "could not resolve: " & $n) + result = errorNode(c, n) + +proc semArrPut(c: PContext; n: PNode; flags: TExprFlags): PNode = + # rewrite `[]=`(a, i, x) back to ``a[i] = x``. + let b = newNodeI(nkBracketExpr, n.info) + b.add(n[1].skipHiddenAddr) + for i in 2..<n.len-1: b.add(n[i]) + result = newNodeI(nkAsgn, n.info, 2) + result[0] = b + result[1] = n.lastSon + result = semAsgn(c, result, noOverloadedSubscript) + +proc semAsgnOpr(c: PContext; n: PNode; k: TNodeKind): PNode = + result = newNodeI(k, n.info, 2) + result[0] = n[1] + result[1] = n[2] + result = semAsgn(c, result, noOverloadedAsgn) + +proc semIsPartOf(c: PContext, n: PNode, flags: TExprFlags): PNode = + var r = isPartOf(n[1], n[2]) + result = newIntNodeT(toInt128(ord(r)), n, c.idgen, c.graph) + +proc expectIntLit(c: PContext, n: PNode): int = + let x = c.semConstExpr(c, n) + case x.kind + of nkIntLit..nkInt64Lit: result = int(x.intVal) + else: + result = 0 + localError(c.config, n.info, errIntLiteralExpected) + +proc semInstantiationInfo(c: PContext, n: PNode): PNode = + result = newNodeIT(nkTupleConstr, n.info, n.typ) + let idx = expectIntLit(c, n[1]) + let useFullPaths = expectIntLit(c, n[2]) + let info = getInfoContext(c.config, idx) + var filename = newNodeIT(nkStrLit, n.info, getSysType(c.graph, n.info, tyString)) + filename.strVal = if useFullPaths != 0: toFullPath(c.config, info) else: toFilename(c.config, info) + var line = newNodeIT(nkIntLit, n.info, getSysType(c.graph, n.info, tyInt)) + line.intVal = toLinenumber(info) + var column = newNodeIT(nkIntLit, n.info, getSysType(c.graph, n.info, tyInt)) + column.intVal = toColumn(info) + # filename: string, line: int, column: int + result.add(newTree(nkExprColonExpr, n.typ.n[0], filename)) + result.add(newTree(nkExprColonExpr, n.typ.n[1], line)) + result.add(newTree(nkExprColonExpr, n.typ.n[2], column)) + +proc toNode(t: PType, i: TLineInfo): PNode = + result = newNodeIT(nkType, i, t) + +const + # these are types that use the bracket syntax for instantiation + # they can be subjected to the type traits `genericHead` and + # `Uninstantiated` + tyUserDefinedGenerics* = {tyGenericInst, tyGenericInvocation, + tyUserTypeClassInst} + + tyMagicGenerics* = {tySet, tySequence, tyArray, tyOpenArray} + + tyGenericLike* = tyUserDefinedGenerics + + tyMagicGenerics + + {tyCompositeTypeClass} + +proc uninstantiate(t: PType): PType = + result = case t.kind + of tyMagicGenerics: t + of tyUserDefinedGenerics: t.base + of tyCompositeTypeClass: uninstantiate t.firstGenericParam + else: t + +proc getTypeDescNode(c: PContext; typ: PType, sym: PSym, info: TLineInfo): PNode = + var resType = newType(tyTypeDesc, c.idgen, sym) + rawAddSon(resType, typ) + result = toNode(resType, info) + +proc buildBinaryPredicate(kind: TTypeKind; c: PContext; context: PSym; a, b: sink PType): PType = + result = newType(kind, c.idgen, context) + result.rawAddSon a + result.rawAddSon b + +proc buildNotPredicate(c: PContext; context: PSym; a: sink PType): PType = + result = newType(tyNot, c.idgen, context, a) + +proc evalTypeTrait(c: PContext; traitCall: PNode, operand: PType, context: PSym): PNode = + const skippedTypes = {tyTypeDesc, tyAlias, tySink} + let trait = traitCall[0] + internalAssert c.config, trait.kind == nkSym + var operand = operand.skipTypes(skippedTypes) + + template operand2: PType = + traitCall[2].typ.skipTypes({tyTypeDesc}) + + if operand.kind == tyGenericParam or (traitCall.len > 2 and operand2.kind == tyGenericParam): + return traitCall ## too early to evaluate + + let s = trait.sym.name.s + case s + of "or", "|": + return buildBinaryPredicate(tyOr, c, context, operand, operand2).toNode(traitCall.info) + of "and": + return buildBinaryPredicate(tyAnd, c, context, operand, operand2).toNode(traitCall.info) + of "not": + return buildNotPredicate(c, context, operand).toNode(traitCall.info) + of "typeToString": + var prefer = preferTypeName + if traitCall.len >= 2: + let preferStr = traitCall[2].strVal + prefer = parseEnum[TPreferedDesc](preferStr) + result = newStrNode(nkStrLit, operand.typeToString(prefer)) + result.typ = getSysType(c.graph, traitCall[1].info, tyString) + result.info = traitCall.info + of "name", "$": + result = newStrNode(nkStrLit, operand.typeToString(preferTypeName)) + result.typ = getSysType(c.graph, traitCall[1].info, tyString) + result.info = traitCall.info + of "arity": + result = newIntNode(nkIntLit, operand.len - ord(operand.kind==tyProc)) + result.typ = newType(tyInt, c.idgen, context) + result.info = traitCall.info + of "genericHead": + var arg = operand + case arg.kind + of tyGenericInst: + result = getTypeDescNode(c, arg.base, operand.owner, traitCall.info) + # of tySequence: # this doesn't work + # var resType = newType(tySequence, operand.owner) + # result = toNode(resType, traitCall.info) # doesn't work yet + else: + localError(c.config, traitCall.info, "expected generic type, got: type $2 of kind $1" % [arg.kind.toHumanStr, typeToString(operand)]) + result = newType(tyError, c.idgen, context).toNode(traitCall.info) + of "stripGenericParams": + result = uninstantiate(operand).toNode(traitCall.info) + of "supportsCopyMem": + let t = operand.skipTypes({tyVar, tyLent, tyGenericInst, tyAlias, tySink, tyInferred}) + let complexObj = containsGarbageCollectedRef(t) or + hasDestructor(t) + result = newIntNodeT(toInt128(ord(not complexObj)), traitCall, c.idgen, c.graph) + of "hasDefaultValue": + result = newIntNodeT(toInt128(ord(not operand.requiresInit)), traitCall, c.idgen, c.graph) + of "isNamedTuple": + var operand = operand.skipTypes({tyGenericInst}) + let cond = operand.kind == tyTuple and operand.n != nil + result = newIntNodeT(toInt128(ord(cond)), traitCall, c.idgen, c.graph) + of "tupleLen": + var operand = operand.skipTypes({tyGenericInst}) + assert operand.kind == tyTuple, $operand.kind + result = newIntNodeT(toInt128(operand.len), traitCall, c.idgen, c.graph) + of "distinctBase": + var arg = operand.skipTypes({tyGenericInst}) + let rec = semConstExpr(c, traitCall[2]).intVal != 0 + while arg.kind == tyDistinct: + arg = arg.base.skipTypes(skippedTypes + {tyGenericInst}) + if not rec: break + result = getTypeDescNode(c, arg, operand.owner, traitCall.info) + of "rangeBase": + # return the base type of a range type + var arg = operand.skipTypes({tyGenericInst}) + if arg.kind == tyRange: + arg = arg.base + result = getTypeDescNode(c, arg, operand.owner, traitCall.info) + of "isCyclic": + var operand = operand.skipTypes({tyGenericInst}) + let isCyclic = canFormAcycle(c.graph, operand) + result = newIntNodeT(toInt128(ord(isCyclic)), traitCall, c.idgen, c.graph) + else: + localError(c.config, traitCall.info, "unknown trait: " & s) + result = newNodeI(nkEmpty, traitCall.info) + +proc semTypeTraits(c: PContext, n: PNode): PNode = + checkMinSonsLen(n, 2, c.config) + let t = n[1].typ + internalAssert c.config, t != nil and t.skipTypes({tyAlias}).kind == tyTypeDesc + if t.len > 0: + # This is either a type known to sem or a typedesc + # param to a regular proc (again, known at instantiation) + result = evalTypeTrait(c, n, t, getCurrOwner(c)) + else: + # a typedesc variable, pass unmodified to evals + result = n + +proc semOrd(c: PContext, n: PNode): PNode = + result = n + let parType = n[1].typ + if isOrdinalType(parType, allowEnumWithHoles=true): + discard + else: + localError(c.config, n.info, errOrdinalTypeExpected % typeToString(parType, preferDesc)) + result.typ = errorType(c) + +proc semBindSym(c: PContext, n: PNode): PNode = + result = copyNode(n) + result.add(n[0]) + + let sl = semConstExpr(c, n[1]) + if sl.kind notin {nkStrLit, nkRStrLit, nkTripleStrLit}: + return localErrorNode(c, n, n[1].info, errStringLiteralExpected) + + let isMixin = semConstExpr(c, n[2]) + if isMixin.kind != nkIntLit or isMixin.intVal < 0 or + isMixin.intVal > high(TSymChoiceRule).int: + return localErrorNode(c, n, n[2].info, errConstExprExpected) + + let id = newIdentNode(getIdent(c.cache, sl.strVal), n.info) + let s = qualifiedLookUp(c, id, {checkUndeclared}) + if s != nil: + # we need to mark all symbols: + var sc = symChoice(c, id, s, TSymChoiceRule(isMixin.intVal)) + if not (c.inStaticContext > 0 or getCurrOwner(c).isCompileTimeProc): + # inside regular code, bindSym resolves to the sym-choice + # nodes (see tinspectsymbol) + return sc + result.add(sc) + else: + errorUndeclaredIdentifier(c, n[1].info, sl.strVal) + +proc opBindSym(c: PContext, scope: PScope, n: PNode, isMixin: int, info: PNode): PNode = + if n.kind notin {nkStrLit, nkRStrLit, nkTripleStrLit, nkIdent}: + return localErrorNode(c, n, info.info, errStringOrIdentNodeExpected) + + if isMixin < 0 or isMixin > high(TSymChoiceRule).int: + return localErrorNode(c, n, info.info, errConstExprExpected) + + let id = if n.kind == nkIdent: n + else: newIdentNode(getIdent(c.cache, n.strVal), info.info) + + let tmpScope = c.currentScope + c.currentScope = scope + let s = qualifiedLookUp(c, id, {checkUndeclared}) + if s != nil: + # we need to mark all symbols: + result = symChoice(c, id, s, TSymChoiceRule(isMixin)) + else: + result = nil + errorUndeclaredIdentifier(c, info.info, if n.kind == nkIdent: n.ident.s + else: n.strVal) + c.currentScope = tmpScope + +proc semDynamicBindSym(c: PContext, n: PNode): PNode = + # inside regular code, bindSym resolves to the sym-choice + # nodes (see tinspectsymbol) + if not (c.inStaticContext > 0 or getCurrOwner(c).isCompileTimeProc): + return semBindSym(c, n) + + if c.graph.vm.isNil: + setupGlobalCtx(c.module, c.graph, c.idgen) + + let + vm = PCtx c.graph.vm + # cache the current scope to + # prevent it lost into oblivion + scope = c.currentScope + + # cannot use this + # vm.config.features.incl dynamicBindSym + + proc bindSymWrapper(a: VmArgs) = + # capture PContext and currentScope + # param description: + # 0. ident, a string literal / computed string / or ident node + # 1. bindSym rule + # 2. info node + a.setResult opBindSym(c, scope, a.getNode(0), a.getInt(1).int, a.getNode(2)) + + let + # although we use VM callback here, it is not + # executed like 'normal' VM callback + idx = vm.registerCallback("bindSymImpl", bindSymWrapper) + # dummy node to carry idx information to VM + idxNode = newIntTypeNode(idx, c.graph.getSysType(TLineInfo(), tyInt)) + + result = copyNode(n) + for x in n: result.add x + result.add n # info node + result.add idxNode + +proc semShallowCopy(c: PContext, n: PNode, flags: TExprFlags): PNode + +proc semOf(c: PContext, n: PNode): PNode = + if n.len == 3: + n[1] = semExprWithType(c, n[1]) + n[2] = semExprWithType(c, n[2], {efDetermineType}) + #restoreOldStyleType(n[1]) + #restoreOldStyleType(n[2]) + let a = skipTypes(n[1].typ, abstractPtrs) + let b = skipTypes(n[2].typ, abstractPtrs) + let x = skipTypes(n[1].typ, abstractPtrs-{tyTypeDesc}) + let y = skipTypes(n[2].typ, abstractPtrs-{tyTypeDesc}) + + if x.kind == tyTypeDesc or y.kind != tyTypeDesc: + localError(c.config, n.info, "'of' takes object types") + elif b.kind != tyObject or a.kind != tyObject: + localError(c.config, n.info, "'of' takes object types") + else: + let diff = inheritanceDiff(a, b) + # | returns: 0 iff `a` == `b` + # | returns: -x iff `a` is the x'th direct superclass of `b` + # | returns: +x iff `a` is the x'th direct subclass of `b` + # | returns: `maxint` iff `a` and `b` are not compatible at all + if diff <= 0: + # optimize to true: + message(c.config, n.info, hintConditionAlwaysTrue, renderTree(n)) + result = newIntNode(nkIntLit, 1) + result.info = n.info + result.typ = getSysType(c.graph, n.info, tyBool) + return result + elif diff == high(int): + if commonSuperclass(a, b) == nil: + localError(c.config, n.info, "'$1' cannot be of this subtype" % typeToString(a)) + else: + message(c.config, n.info, hintConditionAlwaysFalse, renderTree(n)) + result = newIntNode(nkIntLit, 0) + result.info = n.info + result.typ = getSysType(c.graph, n.info, tyBool) + else: + localError(c.config, n.info, "'of' takes 2 arguments") + n.typ = getSysType(c.graph, n.info, tyBool) + result = n + +proc semUnown(c: PContext; n: PNode): PNode = + proc unownedType(c: PContext; t: PType): PType = + case t.kind + of tyTuple: + var elems = newSeq[PType](t.len) + var someChange = false + for i in 0..<t.len: + elems[i] = unownedType(c, t[i]) + if elems[i] != t[i]: someChange = true + if someChange: + result = newType(tyTuple, c.idgen, t.owner) + # we have to use 'rawAddSon' here so that type flags are + # properly computed: + for e in elems: result.rawAddSon(e) + else: + result = t + of tyOwned: result = t.elementType + of tySequence, tyOpenArray, tyArray, tyVarargs, tyVar, tyLent, + tyGenericInst, tyAlias: + let b = unownedType(c, t[^1]) + if b != t[^1]: + result = copyType(t, c.idgen, t.owner) + copyTypeProps(c.graph, c.idgen.module, result, t) + + result[^1] = b + result.flags.excl tfHasOwned + else: + result = t + else: + result = t + + result = copyTree(n[1]) + result.typ = unownedType(c, result.typ) + # little hack for injectdestructors.nim (see bug #11350): + #result[0].typ = nil + +proc turnFinalizerIntoDestructor(c: PContext; orig: PSym; info: TLineInfo): PSym = + # We need to do 2 things: Replace n.typ which is a 'ref T' by a 'var T' type. + # Replace nkDerefExpr by nkHiddenDeref + # nkDeref is for 'ref T': x[].field + # nkHiddenDeref is for 'var T': x<hidden deref [] here>.field + proc transform(c: PContext; n: PNode; old, fresh: PType; oldParam, newParam: PSym): PNode = + result = shallowCopy(n) + if sameTypeOrNil(n.typ, old): + result.typ = fresh + if n.kind == nkSym and n.sym == oldParam: + result.sym = newParam + for i in 0 ..< safeLen(n): + result[i] = transform(c, n[i], old, fresh, oldParam, newParam) + #if n.kind == nkDerefExpr and sameType(n[0].typ, old): + # result = + + result = copySym(orig, c.idgen) + result.info = info + result.flags.incl sfFromGeneric + result.owner = orig + let origParamType = orig.typ.firstParamType + let newParamType = makeVarType(result, origParamType.skipTypes(abstractPtrs), c.idgen) + let oldParam = orig.typ.n[1].sym + let newParam = newSym(skParam, oldParam.name, c.idgen, result, result.info) + newParam.typ = newParamType + # proc body: + result.ast = transform(c, orig.ast, origParamType, newParamType, oldParam, newParam) + # proc signature: + result.typ = newProcType(result.info, c.idgen, result) + result.typ.addParam newParam + +proc semQuantifier(c: PContext; n: PNode): PNode = + checkSonsLen(n, 2, c.config) + openScope(c) + result = newNodeIT(n.kind, n.info, n.typ) + result.add n[0] + let args = n[1] + assert args.kind == nkArgList + for i in 0..args.len-2: + let it = args[i] + var valid = false + if it.kind == nkInfix: + let op = considerQuotedIdent(c, it[0]) + if op.id == ord(wIn): + let v = newSymS(skForVar, it[1], c) + styleCheckDef(c, v) + onDef(it[1].info, v) + let domain = semExprWithType(c, it[2], {efWantIterator}) + v.typ = domain.typ + valid = true + addDecl(c, v) + result.add newTree(nkInfix, it[0], newSymNode(v), domain) + if not valid: + localError(c.config, n.info, "<quantifier> 'in' <range> expected") + result.add forceBool(c, semExprWithType(c, args[^1])) + closeScope(c) + +proc semOld(c: PContext; n: PNode): PNode = + if n[1].kind == nkHiddenDeref: + n[1] = n[1][0] + if n[1].kind != nkSym or n[1].sym.kind != skParam: + localError(c.config, n[1].info, "'old' takes a parameter name") + elif n[1].sym.owner != getCurrOwner(c): + localError(c.config, n[1].info, n[1].sym.name.s & " does not belong to " & getCurrOwner(c).name.s) + result = n + +proc semNewFinalize(c: PContext; n: PNode): PNode = + # Make sure the finalizer procedure refers to a procedure + if n[^1].kind == nkSym and n[^1].sym.kind notin {skProc, skFunc}: + localError(c.config, n.info, "finalizer must be a direct reference to a proc") + elif optTinyRtti in c.config.globalOptions: + let nfin = skipConvCastAndClosure(n[^1]) + let fin = case nfin.kind + of nkSym: nfin.sym + of nkLambda, nkDo: nfin[namePos].sym + else: + localError(c.config, n.info, "finalizer must be a direct reference to a proc") + nil + if fin != nil: + if fin.kind notin {skProc, skFunc}: + # calling convention is checked in codegen + localError(c.config, n.info, "finalizer must be a direct reference to a proc") + + # check if we converted this finalizer into a destructor already: + let t = whereToBindTypeHook(c, fin.typ.firstParamType.skipTypes(abstractInst+{tyRef})) + if t != nil and getAttachedOp(c.graph, t, attachedDestructor) != nil and + getAttachedOp(c.graph, t, attachedDestructor).owner == fin: + discard "already turned this one into a finalizer" + else: + if fin.instantiatedFrom != nil and fin.instantiatedFrom != fin.owner: #undo move + fin.owner = fin.instantiatedFrom + let wrapperSym = newSym(skProc, getIdent(c.graph.cache, fin.name.s & "FinalizerWrapper"), c.idgen, fin.owner, fin.info) + let selfSymNode = newSymNode(copySym(fin.ast[paramsPos][1][0].sym, c.idgen)) + selfSymNode.typ = fin.typ.firstParamType + wrapperSym.flags.incl sfUsed + + let wrapper = c.semExpr(c, newProcNode(nkProcDef, fin.info, body = newTree(nkCall, newSymNode(fin), selfSymNode), + params = nkFormalParams.newTree(c.graph.emptyNode, + newTree(nkIdentDefs, selfSymNode, newNodeIT(nkType, + fin.ast[paramsPos][1][1].info, fin.typ.firstParamType), c.graph.emptyNode) + ), + name = newSymNode(wrapperSym), pattern = fin.ast[patternPos], + genericParams = fin.ast[genericParamsPos], pragmas = fin.ast[pragmasPos], exceptions = fin.ast[miscPos]), {}) + + var transFormedSym = turnFinalizerIntoDestructor(c, wrapperSym, wrapper.info) + transFormedSym.owner = fin + if c.config.backend == backendCpp or sfCompileToCpp in c.module.flags: + let origParamType = transFormedSym.ast[bodyPos][1].typ + let selfSymbolType = makePtrType(c, origParamType.skipTypes(abstractPtrs)) + let selfPtr = newNodeI(nkHiddenAddr, transFormedSym.ast[bodyPos][1].info) + selfPtr.add transFormedSym.ast[bodyPos][1] + selfPtr.typ = selfSymbolType + transFormedSym.ast[bodyPos][1] = c.semExpr(c, selfPtr) + # TODO: suppress var destructor warnings; if newFinalizer is not + # TODO: deprecated, try to implement plain T destructor + bindTypeHook(c, transFormedSym, n, attachedDestructor, suppressVarDestructorWarning = true) + result = addDefaultFieldForNew(c, n) + +proc semPrivateAccess(c: PContext, n: PNode): PNode = + let t = n[1].typ.elementType.toObjectFromRefPtrGeneric + if t.kind == tyObject: + assert t.sym != nil + c.currentScope.allowPrivateAccess.add t.sym + result = newNodeIT(nkEmpty, n.info, getSysType(c.graph, n.info, tyVoid)) + +proc checkDefault(c: PContext, n: PNode): PNode = + result = n + c.config.internalAssert result[1].typ.kind == tyTypeDesc + let constructed = result[1].typ.base + if constructed.requiresInit: + message(c.config, n.info, warnUnsafeDefault, typeToString(constructed)) + +proc magicsAfterOverloadResolution(c: PContext, n: PNode, + flags: TExprFlags; expectedType: PType = nil): PNode = + ## This is the preferred code point to implement magics. + ## ``c`` the current module, a symbol table to a very good approximation + ## ``n`` the ast like it would be passed to a real macro + ## ``flags`` Some flags for more contextual information on how the + ## "macro" is calld. + + case n[0].sym.magic + of mAddr: + checkSonsLen(n, 2, c.config) + result = semAddr(c, n[1]) + of mTypeOf: + result = semTypeOf(c, n) + of mSizeOf: + result = foldSizeOf(c.config, n, n) + of mAlignOf: + result = foldAlignOf(c.config, n, n) + of mOffsetOf: + result = foldOffsetOf(c.config, n, n) + of mArrGet: + result = semArrGet(c, n, flags) + of mArrPut: + result = semArrPut(c, n, flags) + of mAsgn: + if n[0].sym.name.s == "=": + result = semAsgnOpr(c, n, nkAsgn) + elif n[0].sym.name.s == "=sink": + result = semAsgnOpr(c, n, nkSinkAsgn) + else: + result = semShallowCopy(c, n, flags) + of mIsPartOf: result = semIsPartOf(c, n, flags) + of mTypeTrait: result = semTypeTraits(c, n) + of mAstToStr: + result = newStrNodeT(renderTree(n[1], {renderNoComments}), n, c.graph) + result.typ = getSysType(c.graph, n.info, tyString) + of mInstantiationInfo: result = semInstantiationInfo(c, n) + of mOrd: result = semOrd(c, n) + of mOf: result = semOf(c, n) + of mHigh, mLow: result = semLowHigh(c, n, n[0].sym.magic) + of mShallowCopy: result = semShallowCopy(c, n, flags) + of mNBindSym: + if dynamicBindSym notin c.features: + result = semBindSym(c, n) + else: + result = semDynamicBindSym(c, n) + of mProcCall: + result = n + result.typ = n[1].typ + of mDotDot: + result = n + of mPlugin: + let plugin = getPlugin(c.cache, n[0].sym) + if plugin.isNil: + localError(c.config, n.info, "cannot find plugin " & n[0].sym.name.s) + result = n + else: + result = plugin(c, n) + of mNew: + if n[0].sym.name.s == "unsafeNew": # special case for unsafeNew + result = n + else: + result = addDefaultFieldForNew(c, n) + of mNewFinalize: + result = semNewFinalize(c, n) + of mDestroy: + result = n + let t = n[1].typ.skipTypes(abstractVar) + let op = getAttachedOp(c.graph, t, attachedDestructor) + if op != nil: + result[0] = newSymNode(op) + if op.typ != nil and op.typ.len == 2 and op.typ.firstParamType.kind != tyVar: + if n[1].kind == nkSym and n[1].sym.kind == skParam and + n[1].typ.kind == tyVar: + result[1] = genDeref(n[1]) + else: + result[1] = skipAddr(n[1]) + of mTrace: + result = n + let t = n[1].typ.skipTypes(abstractVar) + let op = getAttachedOp(c.graph, t, attachedTrace) + if op != nil: + result[0] = newSymNode(op) + of mDup: + result = n + let t = n[1].typ.skipTypes(abstractVar) + let op = getAttachedOp(c.graph, t, attachedDup) + if op != nil: + result[0] = newSymNode(op) + if op.typ.len == 3: + let boolLit = newIntLit(c.graph, n.info, 1) + boolLit.typ = getSysType(c.graph, n.info, tyBool) + result.add boolLit + of mWasMoved: + result = n + let t = n[1].typ.skipTypes(abstractVar) + let op = getAttachedOp(c.graph, t, attachedWasMoved) + if op != nil: + result[0] = newSymNode(op) + let addrExp = newNodeIT(nkHiddenAddr, result[1].info, makePtrType(c, t)) + addrExp.add result[1] + result[1] = addrExp + of mUnown: + result = semUnown(c, n) + of mExists, mForall: + result = semQuantifier(c, n) + of mOld: + result = semOld(c, n) + of mSetLengthSeq: + result = n + let seqType = result[1].typ.skipTypes({tyPtr, tyRef, # in case we had auto-dereferencing + tyVar, tyGenericInst, tyOwned, tySink, + tyAlias, tyUserTypeClassInst}) + if seqType.kind == tySequence and seqType.base.requiresInit: + message(c.config, n.info, warnUnsafeSetLen, typeToString(seqType.base)) + of mDefault: + result = checkDefault(c, n) + let typ = result[^1].typ.skipTypes({tyTypeDesc}) + let defaultExpr = defaultNodeField(c, result[^1], typ, false) + if defaultExpr != nil: + result = defaultExpr + of mZeroDefault: + result = checkDefault(c, n) + of mIsolate: + if not checkIsolate(n[1]): + localError(c.config, n.info, "expression cannot be isolated: " & $n[1]) + result = n + of mPrivateAccess: + result = semPrivateAccess(c, n) + of mArrToSeq: + result = n + if result.typ != nil and expectedType != nil and result.typ.kind == tySequence and + expectedType.kind == tySequence and result.typ.elementType.kind == tyEmpty: + result.typ = expectedType # type inference for empty sequence # bug #21377 + of mEnsureMove: + result = n + if n[1].kind in {nkStmtListExpr, nkBlockExpr, + nkIfExpr, nkCaseStmt, nkTryStmt}: + localError(c.config, n.info, "Nested expressions cannot be moved: '" & $n[1] & "'") + else: + result = n |