diff options
Diffstat (limited to 'chapter25/src/main')
10 files changed, 125 insertions, 70 deletions
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/Parser.java b/chapter25/src/main/java/com/seaofnodes/simple/Parser.java index 19894357..42c83f93 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/Parser.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/Parser.java @@ -217,13 +217,17 @@ public class Parser { * Parses a function body, assuming the header is parsed. */ private ReturnNode parseFunctionBody( TypeFunPtr sig, Lexer loc, String[] ids) { + return parseFunctionBody(sig, loc, null, ids); + } + + private ReturnNode parseFunctionBody( TypeFunPtr sig, Lexer loc, java.util.BitSet finals, String[] ids) { // Record & restore the existing scope vars. The function parse might // update fields, so when the parse is done reset back to the pre-parse // state. Node[] preParse = _scope.save(); // Parse function body normally - ReturnNode ret = _parseFunctionBody(null, sig,loc,ids); + ReturnNode ret = _parseFunctionBody(null, sig,loc,finals,ids); // Reset all fields to pre-parse days _scope.restore(preParse); @@ -246,6 +250,10 @@ public class Parser { // Unstack the {break,continue,return} scopes. private ReturnNode _parseFunctionBody( String funName, TypeFunPtr sig, Lexer loc, String[] ids) { + return _parseFunctionBody(funName, sig, loc, null, ids); + } + + private ReturnNode _parseFunctionBody( String funName, TypeFunPtr sig, Lexer loc, java.util.BitSet finals, String[] ids) { boolean isInit = FunNode.isInit(funName); boolean isCtor = isInit || isExplicitConstructorName(funName); String typeName = isCtor ? ((TypeMemPtr)sig._sig[0])._obj._name : null; @@ -278,7 +286,7 @@ public class Parser { for( int i=0; i<ids.length; i++ ) { Type t = sig.arg(i); // Args take a default input if called from Start/external-world - _scope.define(ids[i], t, i==0 && ids[0]=="self", new ParmNode(ids[i],i+2,t,fun,ConstantNode.seed(t).peephole()).peephole(), loc); + _scope.define(ids[i], t, (i==0 && ids[0]=="self") || (finals!=null && finals.get(i)), new ParmNode(ids[i],i+2,t,fun,ConstantNode.seed(t).peephole()).peephole(), loc); } // Parse the function body. @@ -434,7 +442,7 @@ public class Parser { // value; otherwise a user constructor must initialize it. Node val = _returnScope.in(vidx); if( upgrade && v._uninit && - !(val._type instanceof TypeNil tn && tn.notNull() && !val._type.isHigh()) ) continue; + !initialized(val._type) ) continue; // Store value into extended struct Node prior = mmm.keep(); Node st = peep(new StoreNode(null, fld._fname, fld._alias, fld._t, null, prior, self, off(tself,fld._fname), val, fld._final)); @@ -455,6 +463,10 @@ public class Parser { // Validate each user constructor, or an implicit empty one, before the // declaration scope goes away. Later fields use their declaration defaults. + private static boolean initialized(Type t) { + return t!=Type.BOTTOM && !t.isHigh() && (!(t instanceof TypeNil tn) || tn.notNull()); + } + private void checkInitFields(TypeStruct ts, int base) { if( _returnScope==null || _returnScope.ctrl()._type.isHigh() ) return; boolean implicit = _ctorExits.isEmpty(); @@ -467,7 +479,7 @@ public class Parser { Var v = _scope.var(idx); if( !v._uninit || v._fref ) continue; Type t = exit.getOrDefault(v,_returnScope.in(idx)._type); - if( !(t instanceof TypeNil tn && tn.notNull() && !t.isHigh()) ) + if( !initialized(t) ) throw error("'"+ts._name+"' is not fully initialized, field '"+fld._fname+ (implicit ? "' needs to be set in a constructor" : "' is only partially set in the constructor"),v._loc); @@ -1025,6 +1037,10 @@ public class Parser { // Widen ints to floats; narrow wide int types. // Early error if types do not match variable. private Node convertExpr( Node expr, Type t ) { + if( !expr._type.accessISA(t) ) + throw error("Type "+expr._type.str()+" is not of declared type "+t.str()); + if( t instanceof TypeMemPtr tmp && tmp.isFinal() ) + expr = peep(new ReadOnlyNode(expr)); // A FunPtr carries the semantic edge to its function's Return. Do not // hide that edge behind a Convert which can fold to a plain constant. if( expr instanceof FunPtrNode && t instanceof TypeFunPtr ) @@ -1090,17 +1106,24 @@ public class Parser { return require(n,";"); } - /** Parse final: [!]var['=' asgn] + // The binding modifier sits immediately before the name. It never + // changes permissions on the referenced object. + private boolean bindingFinal(Type t) { + if( match("!") ) return false; + if( match("~") ) return true; + return t==Type.TOP || t instanceof TypeNil; + } + + /** Parse final: [!|~]var['=' asgn] */ private Node parseDeclaration(Type t) { assert t!=null; // Has var/val instead of a user-declared type boolean inferType = t==Type.TOP || t==Type.BOTTOM; - boolean hasBang = match("!"); + boolean xfinal = bindingFinal(t); Lexer loc = loc(); String name = requireId(); // Optional initializing expression follows - boolean xfinal = false; boolean fld_final = false; // Field is final, but not deeply final boolean uninit = false; // Required non-null constructor field Node expr; @@ -1121,18 +1144,6 @@ public class Parser { } else { expr = parseAsgn(); } - // TOP means val and val is always final - xfinal = (t==Type.TOP) || - expr instanceof ExternNode || - // BOTTOM is var and var is always not-final - (t!=Type.BOTTOM && - // no Bang AND - !hasBang && - // not-null (expecting null to be set to not-null) - expr._type != Type.NIL && - // Pointers are final by default; int/flt are not-final by default. - (t instanceof TypeNil)); - // var/val, then type comes from expression if( inferType ) { if( expr._type==Type.NIL ) @@ -1141,12 +1152,6 @@ public class Parser { if( !xfinal ) t = mutableInferredType(t); } - // Final is deep on ptrs - if( xfinal && t instanceof TypeMemPtr tmp ) { - t = tmp.makeRO(); - expr = peep(new ReadOnlyNode(expr)); - } - // expr is a constant function if( t instanceof TypeFunPtr decl && expr._type instanceof TypeFunPtr tfp && tfp.isConstant() ) { t = decl.makeFrom(tfp.fidx()); @@ -1168,8 +1173,8 @@ public class Parser { // Required pointers retain their declared shape, but include // null until every constructor path assigns them. case TypeNil tn -> tn.nullable() ? con(Type.NIL) : con(t.meet(Type.NIL)); - case TypeInteger ti -> _code.ZERO; - case TypeFloat tf -> con(TypeFloat.FZERO); + case TypeInteger ti -> xfinal ? con(Type.BOTTOM) : _code.ZERO; + case TypeFloat tf -> con(xfinal ? Type.BOTTOM : TypeFloat.FZERO); // Bottom signals type inference: they must be initialized in // the constructor and that's when we'll discover the type. case Type tt -> { assert tt==Type.BOTTOM; yield con(tt); } @@ -1177,9 +1182,9 @@ public class Parser { // Every non-null pointer without a default is constructor-required. // Without `!` it is also shallow-final; mutability and definite // initialization are independent properties. - if( t instanceof TypeNil tn && !tn.nullable() ) { + if( (xfinal && !(t instanceof TypeNil)) || (t instanceof TypeNil tn && !tn.nullable()) ) { uninit = true; - if( !hasBang ) fld_final = true; + if( xfinal ) fld_final = true; } } @@ -1430,8 +1435,10 @@ public class Parser { // Otherwise you get a type name int old1 = pos(); + boolean writable = match("!"); + boolean readonly = !writable && match("~"); String tname = _lexer.matchId(); - if( tname==null ) return null; + if( tname==null ) return posT(old1); // Convert the type name to a type. Type t0 = TYPES.get(tname), t1 = t0; @@ -1544,6 +1551,13 @@ public class Parser { if( t1 instanceof TypeStruct ts1 ) t1 = TypeMemPtr.make(ts1); + // A qualifier before the name applies to the struct reference, not + // to an enclosing array. Arrays have their own [] / [~] qualifier. + if( t1 instanceof TypeMemPtr tmp ) { + if( readonly || !writable ) t1 = tmp.makeRO(); + } else if( writable || readonly ) + return posT(old1); + // Nest arrays and '?' as needed Type t2 = t1; while( true ) { @@ -1554,7 +1568,7 @@ public class Parser { } else throw error("Type "+t0+" cannot be null"); } else if( match("[~]") ) { - t2 = TypeMemPtr.make(typeAry(t2,true)); + t2 = TypeMemPtr.make(typeAry(t2,true)).makeRO(); } else if( match("[]") ) { t2 = TypeMemPtr.make(typeAry(t2,false)); } else @@ -1566,7 +1580,7 @@ public class Parser { // Check valid forward ref, after parsing all the type extra bits. // Cannot check earlier, because cannot find required 'id' until after "[]?" syntax int old2 = pos(); - match("!"); + if( !match("!") ) match("~"); String id = _lexer.matchId(); if( !(peek(',') || peek(';') || peek('=') || match("->")) || id==null ) return posT(old1); // Reset lexer to reparse @@ -1616,9 +1630,8 @@ public class Parser { ta = TypeStruct.makeAry(tname,TypeInteger.U32,_code.alias(rcname),t,_code.alias(rcname), false ); TYPES.put(tname,ta); } - if( !efinal ) return ta; // Already have the aliases, just efinal is wrong - return TypeStruct.makeAry(tname,TypeInteger.U32,ta._fields[0]._alias,t,ta._fields[1]._alias,true ); + return TypeStruct.makeAry(tname,TypeInteger.U32,ta._fields[0]._alias,t,ta._fields[1]._alias,efinal ); } private Type implicitSelfType() { @@ -2187,7 +2200,7 @@ public class Parser { // array body. TypeMemPtr str = TypeMemPtr.make((byte)2,TypeStruct.makeAry("[]u8", slen, lenAlias, body, elemAlias, true),true); assert str.isConstant(); - return con(str); + return con(str.makeRO()); } /** @@ -2305,6 +2318,8 @@ public class Parser { Node mem = mem(); // Store to field mem.keep(); + if( expr._type instanceof TypeMemPtr view && view._ro && ctrl()._type!=Type.XCONTROL ) + throw error("Cannot modify final field '"+name+"'"); Node st = new StoreNode(loc(), name, alias, decl, ctrl(), mem, expr.unkeep(), off.unkeep(), lift, false).peephole().keep(); storeMem(st,alias,mem); st.unkeep(); @@ -2330,6 +2345,8 @@ public class Parser { throw error( "'" + ts._name + "' is not fully initialized, field '" + fld._fname + "' needs to be set in a constructor" ); Node op = opAssign(ch,load, decl ).keep(); mem.keep(); + if( expr._type instanceof TypeMemPtr view && view._ro && ctrl()._type!=Type.XCONTROL ) + throw error("Cannot modify final field '"+name+"'"); Node st = new StoreNode(loc(), name, alias, decl, ctrl(), mem, expr.unkeep(), off.unkeep(), op, false).peephole().keep(); storeMem(st,alias,mem); st.unkeep(); @@ -2375,6 +2392,7 @@ public class Parser { private Node func() { Ary<Type> ts = new Ary<>(Type.class); Ary<String> ids = new Ary<>(String.class); + java.util.BitSet finals = new java.util.BitSet(); Type self = implicitSelfType(); ts.push(self); ids.push(self == TypePtr.PTR ? "#self" : "self"); @@ -2385,6 +2403,7 @@ public class Parser { while( true ) { Type t = type(); // Arg type if( t==null ) break; + finals.set(ids.size(),bindingFinal(t)); String id = requireId(); ts .push(t ); // Push type/arg pairs ids.push(id); @@ -2393,7 +2412,7 @@ public class Parser { require("->"); // Make a concrete function type, with a fidx TypeFunPtr tfp = TypeFunPtr.make1((byte)2,true,ts.asAry(),Type.BOTTOM,_code.fidx(_ref._cname)); - ReturnNode ret = parseFunctionBody(tfp,loc,ids.asAry()); + ReturnNode ret = parseFunctionBody(tfp,loc,finals,ids.asAry()); return new FunPtrNode(tfp,_code._start,ret).peephole(); } @@ -2401,6 +2420,7 @@ public class Parser { require("{"); Ary<Type> ts = new Ary<>(Type.class); Ary<String> ids = new Ary<>(String.class); + java.util.BitSet finals = new java.util.BitSet(); TypeStruct self = _scope.constructorSelf(); assert self != null; ts.push(TypeMemPtr.make(constructorRecv(self))); @@ -2416,6 +2436,7 @@ public class Parser { while( true ) { Type t = type(); if( t==null ) break; + finals.set(ids.size(),bindingFinal(t)); String id = requireId(); ts .push(t ); ids.push(id); @@ -2424,7 +2445,7 @@ public class Parser { require("->"); TypeFunPtr tfp = TypeFunPtr.make1((byte)2,true,ts.asAry(),TypeMem.makePrivate(self),_code.fidx(_ref._cname)); Node[] preParse = _scope.save(); - ReturnNode ret = _parseFunctionBody((self._name+"."+name).intern(),tfp,loc,ids.asAry()); + ReturnNode ret = _parseFunctionBody((self._name+"."+name).intern(),tfp,loc,finals,ids.asAry()); _scope.restore(preParse); require("}"); return new FunPtrNode(tfp,_code._start,ret).peephole(); diff --git a/chapter25/src/main/java/com/seaofnodes/simple/codegen/Serialize.java b/chapter25/src/main/java/com/seaofnodes/simple/codegen/Serialize.java index ee5c48df..a8cd315f 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/codegen/Serialize.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/codegen/Serialize.java @@ -63,8 +63,9 @@ abstract public class Serialize { Type.TAGOFFS(); BAOS baos = new BAOS(); + // C0D2 adds independent pointer access permissions to serialized types. // A - Print a header - baos.write('C').write('0').write('D').write('E'); + baos.write('C').write('0').write('D').write('2'); // Count unique Types var types = new HashMap<Type,Integer>(); @@ -217,8 +218,8 @@ abstract public class Serialize { Type.TAGOFFS(); // A - Read a header - if( bais.read()!='C' || bais.read()!='0' || bais.read()!='D' || bais.read()!='E' ) - throw new IllegalArgumentException("Missing magic word"); + if( bais.read()!='C' || bais.read()!='0' || bais.read()!='D' || bais.read()!='2' ) + throw new IllegalArgumentException("Unsupported serialized IR format; rebuild the object file"); // B - Packed read of #strings, then strings int ndependents = bais.packed4(); // Number of dependent object files @@ -246,8 +247,8 @@ abstract public class Serialize { String[] strs = elf._strs; if( strs == null ) { // A - Read a header - if( bais.read() != 'C' || bais.read() != '0' || bais.read() != 'D' || bais.read() != 'E' ) - throw new IllegalArgumentException( "Missing magic word" ); + if( bais.read() != 'C' || bais.read() != '0' || bais.read() != 'D' || bais.read() != '2' ) + throw new IllegalArgumentException( "Unsupported serialized IR format; rebuild the object file" ); // B - Packed read of #strings, then strings int ndependents = bais.packed4(); // Number of dependent object files diff --git a/chapter25/src/main/java/com/seaofnodes/simple/node/CallEndNode.java b/chapter25/src/main/java/com/seaofnodes/simple/node/CallEndNode.java index 2e921301..162f9c24 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/node/CallEndNode.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/node/CallEndNode.java @@ -227,7 +227,7 @@ public class CallEndNode extends CFGNode implements MultiNode { // references here. Compare against its recursively upgraded form, // so deep mutability requirements participate before inlining. Type formal = tfp.arg(i).upgradeType(Parser.TYPES); - if( !arg._type.isa(formal) ) + if( !arg._type.isa(formal) || !arg._type.accessISA(formal) ) { addDep(arg); return false; } } return true; diff --git a/chapter25/src/main/java/com/seaofnodes/simple/node/CallNode.java b/chapter25/src/main/java/com/seaofnodes/simple/node/CallNode.java index 84f1e705..4372e2d5 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/node/CallNode.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/node/CallNode.java @@ -187,7 +187,7 @@ public class CallNode extends CFGNode { // Check for args for( int i=0; i<tfp.nargs(); i++ ) - if( !arg(i+2)._type.isa(tfp.arg(i)) ) { + if( !arg(i+2)._type.isa(tfp.arg(i)) || !arg(i+2)._type.accessISA(tfp.arg(i)) ) { // Constructors return private memory and carry hidden self and // selfMem arguments ahead of the source-level arguments. int argno = i - (tfp.ret() instanceof TypeMem ? 2 : 0); diff --git a/chapter25/src/main/java/com/seaofnodes/simple/node/ConvertNode.java b/chapter25/src/main/java/com/seaofnodes/simple/node/ConvertNode.java index 4ee5521a..b038366a 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/node/ConvertNode.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/node/ConvertNode.java @@ -35,7 +35,7 @@ public class ConvertNode extends Node { Type src = val()._type; if( CodeGen.CODE._phase == CodeGen.Phase.Opto ) { if( src.isHigh() ) return Type.TOP; - if( src.isa(_dst) ) return src; + if( (src.isa(_dst) && src.accessISA(_dst)) ) return src; } return _dst; } @@ -43,7 +43,7 @@ public class ConvertNode extends Node { @Override public Node idealize() { Type src = val()._type; if( src==Type.BOTTOM || src==Type.TOP ) return null; - if( src.isa(_dst) ) return val(); + if( (src.isa(_dst) && src.accessISA(_dst)) ) return val(); // Managed arrays are represented by an object pointer, while C wants // the address of the first element. The representation cast itself is diff --git a/chapter25/src/main/java/com/seaofnodes/simple/node/LoadNode.java b/chapter25/src/main/java/com/seaofnodes/simple/node/LoadNode.java index a2345d92..a557f97c 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/node/LoadNode.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/node/LoadNode.java @@ -85,6 +85,7 @@ public class LoadNode extends MemOpNode { return tmp.isHigh() || tmp._obj.isHigh() ? TypeScalar.TOP : TypeScalar.BOT; Type t = pfld._t; + boolean readonly = t instanceof TypeMemPtr view && view._ro; // Load member of constant array if( t instanceof TypeConAry ary ) t = ary.elem(); // TODO: if offset is known, can peek the constant @@ -93,7 +94,7 @@ public class LoadNode extends MemOpNode { // A deeply read-only base produces a deeply read-only value. The // generic declared field type must not cast this information away. - if( ptr0.isFinal() ) + if( ptr0.isFinal() || readonly ) t = t.makeRO(); return scalar(t); } @@ -306,7 +307,7 @@ public class LoadNode extends MemOpNode { // Read-Only is a deep property, and cannot be cast-away private Node castRO(Node rez) { - if( ptr()._type.isFinal() && !rez._type.isFinal() ) + if( (ptr()._type.isFinal() || declaredType().isFinal()) && !rez._type.isFinal() ) return new ReadOnlyNode(rez).peephole(); return rez; } diff --git a/chapter25/src/main/java/com/seaofnodes/simple/node/StoreNode.java b/chapter25/src/main/java/com/seaofnodes/simple/node/StoreNode.java index 7e2963f2..415ade34 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/node/StoreNode.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/node/StoreNode.java @@ -269,7 +269,7 @@ public class StoreNode extends MemOpNode { return null; TypeMemPtr tmp = (TypeMemPtr)ptr()._type; Field f = tmp._obj.field(_name); - if( f!=null && f._final && !_init ) + if( f!=null && (tmp._ro || f._final) && !_init ) return Parser.error("Cannot modify final field '"+_name+"'",_loc); return null; } diff --git a/chapter25/src/main/java/com/seaofnodes/simple/type/Type.java b/chapter25/src/main/java/com/seaofnodes/simple/type/Type.java index d1af6ca8..980daf0f 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/type/Type.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/type/Type.java @@ -468,6 +468,10 @@ public class Type /*implements Cloneable*/ { boolean _isConstant() { return _type==TNIL; } // Are all reachable struct Fields are final? + // Writable array slots are invariant in their element access permissions. + // Otherwise an alias could insert a readonly pointer into a writable slot. + public boolean accessISA(Type dst) { return true; } + public final boolean isFinal() { return recurClose(recurOpen()._isFinal()); } boolean _isFinal() { assert is_nokids(); return true; } diff --git a/chapter25/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java b/chapter25/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java index cfd213b7..175b1c63 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/type/TypeMemPtr.java @@ -27,12 +27,15 @@ public class TypeMemPtr extends TypeNil { // (TOP ,true ) - a nil public TypeStruct _obj; + // Deep read-only access through this pointer; independent of slot finality. + public boolean _ro; + public boolean _one; // Singleton pointer value; the pointer itself is constant. public boolean _pub; // Escaped/public pointer. False means constructor-private. private static final Ary<TypeMemPtr> FREE = new Ary<>(TypeMemPtr.class); private TypeMemPtr(byte nil, TypeStruct obj, boolean one, boolean pub) { super(TMEMPTR,nil); init(nil,obj,one,pub); } - private TypeMemPtr init(byte nil, TypeStruct obj, boolean one, boolean pub) { _nil=nil; _obj=obj; _one=one; _pub=pub; return this; } + private TypeMemPtr init(byte nil, TypeStruct obj, boolean one, boolean pub) { _nil=nil; _obj=obj; _ro=obj==TypeStruct.BOT; _one=one; _pub=pub; return this; } // Return a filled-in TypeMemPtr; either from free list or alloc new. static TypeMemPtr malloc(byte nil, TypeStruct obj, boolean one, boolean pub) { return FREE.isEmpty() ? new TypeMemPtr(nil,obj,one,pub) : FREE.pop().init(nil,obj,one,pub); @@ -43,7 +46,10 @@ public class TypeMemPtr extends TypeNil { return make(nil,obj,one,true); } public static TypeMemPtr make(byte nil, TypeStruct obj, boolean one, boolean pub) { - TypeMemPtr tmp = malloc(nil, obj, one, pub); + return make(nil,obj,one, pub,obj==TypeStruct.BOT); + } + private static TypeMemPtr make(byte nil, TypeStruct obj, boolean one, boolean pub, boolean ro) { + TypeMemPtr tmp = malloc(nil, obj, one, pub).access(ro); TypeMemPtr t2 = tmp.intern(); if( t2==tmp ) return tmp; return VISIT.isEmpty() ? t2.free(tmp) : t2.delayFree(tmp); @@ -66,15 +72,36 @@ public class TypeMemPtr extends TypeNil { public static TypeMemPtr makeNullable(TypeStruct obj) { return make((byte)3, obj); } public static TypeMemPtr makePrivate (TypeStruct obj) { return make((byte)2, obj, false, false); } - public TypeMemPtr makeFrom(TypeStruct obj) { return obj==_obj ? this : make(_nil, obj, _one, _pub); } + public TypeMemPtr makeFrom(TypeStruct obj) { return obj==_obj ? this : make(_nil, obj, _one, _pub,_ro); } public TypeMemPtr makeNullable() { return makeFrom((byte)3); } /** Inferred mutable local: nullable, public and non-singleton. */ public TypeMemPtr makeVar() { return (TypeMemPtr)makeStorage(); } /** Public-memory shape: nullable and non-singleton, preserving the referent. */ - @Override TypeMemPtr _makeStorage() { return make(_nil,_obj._makeStorage(),false,true); } - @Override TypeMemPtr makeFrom(byte nil) { return nil==_nil ? this : make(nil, _obj, _one, _pub); } + @Override TypeMemPtr _makeStorage() { return make(_nil,_obj._makeStorage(),false,true,_ro); } + @Override TypeMemPtr makeFrom(byte nil) { return nil==_nil ? this : make(nil, _obj, _one, _pub,_ro); } @Override public Type nonZero() { return makeFrom((byte)(_nil <= 1 ? 1 : 2)); } + private TypeMemPtr access(boolean ro) { _ro=ro; return this; } + + public TypeMemPtr withAccess(boolean ro) { + if( _ro==ro ) return this; + TypeMemPtr ptr = malloc(_nil, _obj, _one, _pub); + ptr._ro = ro; + TypeMemPtr res = ptr.intern(); + if( res==ptr ) return ptr; + return VISIT.isEmpty() ? res.free(ptr) : res.delayFree(ptr); + } + + // Writable slots can load and store references, so their element access + // must agree in both directions. A read-only outer view can weaken access. + @Override public boolean accessISA(Type dst) { + if( !(dst instanceof TypeMemPtr ptr) ) return true; + if( _ro && !ptr._ro ) return false; + if( ptr._ro || _obj._fields==null || ptr._obj._fields==null || !_obj.isAry() || !ptr._obj.isAry() ) return true; + Type a = _obj._fields[1]._t, b = ptr._obj._fields[1]._t; + return a.accessISA(b) && b.accessISA(a); + } + // An abstract pointer, pointing to either a Struct or an Array. // Can also be null or not, so 4 choices {TOP,BOT} x {nil,not} public static final TypeMemPtr BOT = make((byte)3, TypeStruct.BOT); @@ -82,7 +109,7 @@ public class TypeMemPtr extends TypeNil { public static final TypeMemPtr NOTBOT = make((byte)2,TypeStruct.BOT); public static final TypeMemPtr TEST= make((byte)2, TypeStruct.TEST); - public static void gather(ArrayList<Type> ts) { ts.add(NOTBOT); ts.add(BOT); ts.add(TEST); } + public static void gather(ArrayList<Type> ts) { ts.add(NOTBOT); ts.add(BOT); ts.add(TEST); ts.add(TEST.makeRO()); } @Override public TypeNil xmeet(Type t) { @@ -91,28 +118,28 @@ public class TypeMemPtr extends TypeNil { // Can't keep _one if mixing two unequal singletons; the result is not // either singleton. Once either side is public, the meet is public. boolean one = _one && that._one && (_obj==that._obj || !(_obj.isConAry() || that._obj.isConAry())); - return make(xmeet0(that), (TypeStruct)_obj.meet(that._obj), one, _pub | that._pub); + return make(xmeet0(that), (TypeStruct)_obj.meet(that._obj), one, _pub | that._pub,_ro | that._ro); } @Override - TypeMemPtr xdual() { return malloc( dual0(), _obj.dual(), !_one, !_pub); } + TypeMemPtr xdual() { return malloc( dual0(), _obj.dual(), !_one, !_pub).access(!_ro); } @Override TypeMemPtr rdual() { if( _dual!=null ) return dual(); assert !_terned; - TypeMemPtr d = malloc(dual0(), null, !_one, !_pub); + TypeMemPtr d = malloc(dual0(), null, !_one, !_pub).access(!_ro); (_dual = d)._dual = this; // Cross link duals d._obj = _obj._terned ? _obj.dual() : _obj.rdual(); return d; } // RHS is NIL; do not deep-dual when crossing the center line - @Override Type meet0() { return _nil==3 ? this : make((byte)3,_obj); } + @Override Type meet0() { return _nil==3 ? this : make((byte)3,_obj,false,true,_ro); } @Override boolean _isConstant() { return _one; } - @Override boolean _isFinal() { return _obj._isFinal(); } - @Override TypeMemPtr _makeRO() { return makeFrom(_obj._makeRO()); } - @Override TypeMemPtr _close( String name, HashMap<String, Type> TYPES ) { return malloc(_nil,_obj._close(name, TYPES ),_one,_pub); } + @Override boolean _isFinal() { return _ro; } + @Override TypeMemPtr _makeRO() { return withAccess(true); } + @Override TypeMemPtr _close( String name, HashMap<String, Type> TYPES ) { return malloc(_nil,_obj._close(name, TYPES ),_one,_pub).access(_ro); } @Override Type _upgradeType(HashMap<String,Type> TYPES) { return makeFrom((TypeStruct)_obj._upgradeType(TYPES)); @@ -120,33 +147,34 @@ public class TypeMemPtr extends TypeNil { @Override public int log_size() { return 3; } // (1<<3)==8-byte pointers - @Override int hash() { return _obj.hashCode() ^ super.hash() ^ (_one ? 2048 : 0) ^ (_pub ? 4096 : 0); } + @Override int hash() { return (_ro ? 8192 : 0) ^ _obj.hashCode() ^ super.hash() ^ (_one ? 2048 : 0) ^ (_pub ? 4096 : 0); } @Override boolean eq(Type t) { TypeMemPtr ptr = (TypeMemPtr)t; // Invariant - return super.eq(ptr) && _one == ptr._one && _pub == ptr._pub && _obj == ptr._obj; + return _ro==ptr._ro && super.eq(ptr) && _one == ptr._one && _pub == ptr._pub && _obj == ptr._obj; } @Override boolean cycle_eq(Type t) { if( t._type != TMEMPTR ) return false; TypeMemPtr ptr = (TypeMemPtr)t; // Invariant - return super.eq(ptr) && _one == ptr._one && _pub == ptr._pub && _obj.cycle_eq(ptr._obj); + return _ro==ptr._ro && super.eq(ptr) && _one == ptr._one && _pub == ptr._pub && _obj.cycle_eq(ptr._obj); } @Override public int nkids() { return 1; } @Override public Type at( int idx ) { return _obj; } @Override public void set( int idx, Type t ) { _obj = (TypeStruct)t; } - // Reserve tags for null/not, one/general and public/private - @Override int TAGOFF() { return 8; } + // Reserve tags for null/not, one/general, public/private and read-only access + @Override int TAGOFF() { return 16; } @Override public void packed( BAOS baos, HashMap<String,Integer> strs ) { assert _nil>=2; baos.write(TAGOFFS[_type] + (_nil==2 ? 0 : 1) + (!_one ? 0 : 2) - + (!_pub ? 0 : 4) ); + + (!_pub ? 0 : 4) + + (!_ro ? 0 : 8) ); } static TypeMemPtr packed( int tag, BAOS bais ) { - return malloc((byte)((tag&1)+2),null,(tag&2)==2,(tag&4)==4); + return malloc((byte)((tag&1)+2),null,(tag&2)==2,(tag&4)==4).access((tag&8)==8); } @Override public String str() { diff --git a/chapter25/src/main/smp/sys/aryi64.smp b/chapter25/src/main/smp/sys/aryi64.smp index 22ee082e..98b72605 100644 --- a/chapter25/src/main/smp/sys/aryi64.smp +++ b/chapter25/src/main/smp/sys/aryi64.smp @@ -53,7 +53,7 @@ struct aryi64 { // parseAryI64 & aryi64.str are bijections modulo whitespace. // Returns null if the parse failed, without giving a clue as to why. val parseAryI64 = { u8[~] str -> - scan !s = new scan(str); + !scan !s = new scan(str); if( !s.match('[') ) return null; // Array of parsed results var nums = new aryi64(new i64[1]); |