diff options
Diffstat (limited to 'compiler/semdestruct.nim')
| -rw-r--r-- | compiler/semdestruct.nim | 158 |
1 files changed, 91 insertions, 67 deletions
diff --git a/compiler/semdestruct.nim b/compiler/semdestruct.nim index 797d8895e..791bef823 100644 --- a/compiler/semdestruct.nim +++ b/compiler/semdestruct.nim @@ -9,26 +9,39 @@ ## This module implements destructors. +# included from sem.nim # special marker values that indicates that we are # 1) AnalyzingDestructor: currently analyzing the type for destructor # generation (needed for recursive types) # 2) DestructorIsTrivial: completed the analysis before and determined # that the type has a trivial destructor -var AnalyzingDestructor, DestructorIsTrivial: PSym -new(AnalyzingDestructor) -new(DestructorIsTrivial) +var analyzingDestructor, destructorIsTrivial: PSym +new(analyzingDestructor) +new(destructorIsTrivial) var destructorName = getIdent"destroy_" destructorParam = getIdent"this_" - destructorPragma = newIdentNode(getIdent"destructor", UnknownLineInfo()) + destructorPragma = newIdentNode(getIdent"destructor", unknownLineInfo()) rangeDestructorProc*: PSym -proc instantiateDestructor(c: PContext, typ: PType): bool +proc instantiateDestructor(c: PContext, typ: PType): PType proc doDestructorStuff(c: PContext, s: PSym, n: PNode) = - let t = s.typ.sons[1].skipTypes({tyVar}) + var t = s.typ.sons[1].skipTypes({tyVar}) + if t.kind == tyGenericInvokation: + for i in 1 .. <t.sonsLen: + if t.sons[i].kind != tyGenericParam: + localError(n.info, errDestructorNotGenericEnough) + return + t = t.base + elif t.kind == tyCompositeTypeClass: + t = t.base + if t.kind != tyGenericBody: + localError(n.info, errDestructorNotGenericEnough) + return + t.destructor = s # automatically insert calls to base classes' destructors if n.sons[bodyPos].kind != nkEmpty: @@ -36,15 +49,19 @@ proc doDestructorStuff(c: PContext, s: PSym, n: PNode) = # when inheriting directly from object # there will be a single nil son if t.sons[i] == nil: continue - if instantiateDestructor(c, t.sons[i]): + let destructableT = instantiateDestructor(c, t.sons[i]) + if destructableT != nil: n.sons[bodyPos].addSon(newNode(nkCall, t.sym.info, @[ - useSym(t.sons[i].destructor), + useSym(destructableT.destructor), n.sons[paramsPos][1][0]])) -proc destroyField(c: PContext, field: PSym, holder: PNode): PNode = - if instantiateDestructor(c, field.typ): +proc destroyFieldOrFields(c: PContext, field: PNode, holder: PNode): PNode + +proc destroySym(c: PContext, field: PSym, holder: PNode): PNode = + let destructableT = instantiateDestructor(c, field.typ) + if destructableT != nil: result = newNode(nkCall, field.info, @[ - useSym(field.typ.destructor), + useSym(destructableT.destructor), newNode(nkDotExpr, field.info, @[holder, useSym(field)])]) proc destroyCase(c: PContext, n: PNode, holder: PNode): PNode = @@ -55,78 +72,83 @@ proc destroyCase(c: PContext, n: PNode, holder: PNode): PNode = for i in countup(1, n.len - 1): # of A, B: var caseBranch = newNode(n[i].kind, n[i].info, n[i].sons[0 .. -2]) - let recList = n[i].lastSon - var destroyRecList = newNode(nkStmtList, n[i].info, @[]) - template addField(f: expr): stmt = - let stmt = destroyField(c, f, holder) - if stmt != nil: - destroyRecList.addSon(stmt) - inc nonTrivialFields - - case recList.kind - of nkSym: - addField(recList.sym) - of nkRecList: - for j in countup(0, recList.len - 1): - addField(recList[j].sym) + + let stmt = destroyFieldOrFields(c, n[i].lastSon, holder) + if stmt == nil: + caseBranch.addSon(newNode(nkStmtList, n[i].info, @[])) else: - internalAssert false - - caseBranch.addSon(destroyRecList) + caseBranch.addSon(stmt) + nonTrivialFields += stmt.len + result.addSon(caseBranch) + # maybe no fields were destroyed? if nonTrivialFields == 0: result = nil - + +proc destroyFieldOrFields(c: PContext, field: PNode, holder: PNode): PNode = + template maybeAddLine(e: expr): stmt = + let stmt = e + if stmt != nil: + if result == nil: result = newNode(nkStmtList) + result.addSon(stmt) + + case field.kind + of nkRecCase: + maybeAddLine destroyCase(c, field, holder) + of nkSym: + maybeAddLine destroySym(c, field.sym, holder) + of nkRecList: + for son in field: + maybeAddLine destroyFieldOrFields(c, son, holder) + else: + internalAssert false + proc generateDestructor(c: PContext, t: PType): PNode = ## generate a destructor for a user-defined object or tuple type ## returns nil if the destructor turns out to be trivial - template addLine(e: expr): stmt = - if result == nil: result = newNode(nkStmtList) - result.addSon(e) - # XXX: This may be true for some C-imported types such as # Tposix_spawnattr if t.n == nil or t.n.sons == nil: return internalAssert t.n.kind == nkRecList - let destructedObj = newIdentNode(destructorParam, UnknownLineInfo()) + let destructedObj = newIdentNode(destructorParam, unknownLineInfo()) # call the destructods of all fields - for s in countup(0, t.n.sons.len - 1): - case t.n.sons[s].kind - of nkRecCase: - let stmt = destroyCase(c, t.n.sons[s], destructedObj) - if stmt != nil: addLine(stmt) - of nkSym: - let stmt = destroyField(c, t.n.sons[s].sym, destructedObj) - if stmt != nil: addLine(stmt) - else: - internalAssert false + result = destroyFieldOrFields(c, t.n, destructedObj) # base classes' destructors will be automatically called by # semProcAux for both auto-generated and user-defined destructors -proc instantiateDestructor(c: PContext, typ: PType): bool = - # returns true if the type already had a user-defined - # destructor or if the compiler generated a default - # member-wise one - var t = skipTypes(typ, {tyConst, tyMutable}) +proc instantiateDestructor(c: PContext, typ: PType): PType = + # returns nil if a variable of type `typ` doesn't require a + # destructor. Otherwise, returns the type, which holds the + # destructor that must be used for the varialbe. + # The destructor is either user-defined or automatically + # generated by the compiler in a member-wise fashion. + var t = skipTypes(typ, {tyConst, tyMutable}).skipGenericAlias + let typeHoldingUserDefinition = if t.kind == tyGenericInst: t.base + else: t - if t.destructor != nil: + if typeHoldingUserDefinition.destructor != nil: # XXX: This is not entirely correct for recursive types, but we need # it temporarily to hide the "destroy is already defined" problem - return t.destructor notin [AnalyzingDestructor, DestructorIsTrivial] + if typeHoldingUserDefinition.destructor notin + [analyzingDestructor, destructorIsTrivial]: + return typeHoldingUserDefinition + else: + return nil + t = t.skipTypes({tyGenericInst}) case t.kind of tySequence, tyArray, tyArrayConstr, tyOpenArray, tyVarargs: - if instantiateDestructor(c, t.sons[0]): + if instantiateDestructor(c, t.sons[0]) != nil: if rangeDestructorProc == nil: rangeDestructorProc = searchInScopes(c, getIdent"nimDestroyRange") t.destructor = rangeDestructorProc - return true + return t else: - return false + return nil of tyTuple, tyObject: - t.destructor = AnalyzingDestructor + t.destructor = analyzingDestructor let generated = generateDestructor(c, t) if generated != nil: internalAssert t.sym != nil @@ -139,21 +161,21 @@ proc instantiateDestructor(c: PContext, typ: PType): bool = emptyNode, newNode(nkIdentDefs, i, @[ newIdentNode(destructorParam, i), - useSym(t.sym), + symNodeFromType(c, makeVarType(c, t), t.sym.info), emptyNode]), ]), newNode(nkPragma, i, @[destructorPragma]), emptyNode, generated ]) - discard semProc(c, fullDef) - internalAssert t.destructor != nil - return true + let semantizedDef = semProc(c, fullDef) + t.destructor = semantizedDef[namePos].sym + return t else: - t.destructor = DestructorIsTrivial - return false + t.destructor = destructorIsTrivial + return nil else: - return false + return nil proc insertDestructors(c: PContext, varSection: PNode): tuple[outer, inner: PNode] = @@ -179,9 +201,11 @@ proc insertDestructors(c: PContext, varId = varSection[j][0] varTyp = varId.sym.typ info = varId.info - - if varTyp != nil and instantiateDestructor(c, varTyp) and - sfGlobal notin varId.sym.flags: + + if varTyp == nil or sfGlobal in varId.sym.flags: continue + let destructableT = instantiateDestructor(c, varTyp) + + if destructableT != nil: var tryStmt = newNodeI(nkTryStmt, info) if j < totalVars - 1: @@ -198,11 +222,11 @@ proc insertDestructors(c: PContext, else: result.inner = newNodeI(nkStmtList, info) tryStmt.addSon(result.inner) - + tryStmt.addSon( newNode(nkFinally, info, @[ semStmt(c, newNode(nkCall, info, @[ - useSym(varTyp.destructor), + useSym(destructableT.destructor), useSym(varId.sym)]))])) result.outer = newNodeI(nkStmtList, info) |