diff options
Diffstat (limited to 'chapter25/src/main/java')
| -rw-r--r-- | chapter25/src/main/java/com/seaofnodes/simple/Parser.java | 64 |
1 files changed, 36 insertions, 28 deletions
diff --git a/chapter25/src/main/java/com/seaofnodes/simple/Parser.java b/chapter25/src/main/java/com/seaofnodes/simple/Parser.java index 56233250..727b1c61 100644 --- a/chapter25/src/main/java/com/seaofnodes/simple/Parser.java +++ b/chapter25/src/main/java/com/seaofnodes/simple/Parser.java @@ -1228,17 +1228,17 @@ public class Parser { // Pre-dec/pre-inc int old = pos(); if( match("--") || match("++") ) { - int delta = _lexer.peek(-1)=='+' ? 1 : -1; // Pre vs post + int delta = _lexer.peek(-1)=='+' ? 1 : -1; // Inc vs Dec + int start = pos(); String name = _lexer.matchId(); - if( name!=null ) { - Var n = _scope.lookup(name); - if( n != null && !(n.type() instanceof TypeMemPtr) ) { - if( n._final ) - throw error("Cannot reassign final '"+n._name+"'"); - Node expr = liftExpr(peep(new AddNode(_scope.in(n),con(delta))),n.type(),true); - _scope.update(n,expr); - return expr; - } + Var var = name==null ? null : _scope.lookup(name); + if( var!=null && !(var.type() instanceof TypeMemPtr) ) { + if( var._final ) + throw error("Cannot reassign final '"+var._name+"'"); + // Resolve fields just as a read or postfix update does. Updating + // their declaration's local slot would silently lose the Store. + pos(start); + return parsePrimary(delta); } // Reset, try again pos(old); @@ -1259,7 +1259,10 @@ public class Parser { * </pre> * @return a primary {@link Node}, never {@code null} */ - private Node parsePrimary() { + private Node parsePrimary() { return parsePrimary(0); } + + // pre is +/-1 for a prefix update of a known name, zero otherwise. + private Node parsePrimary(int pre) { if( _lexer.isNumber(_lexer.peek()) ) return parseLiteral(); if( _lexer.peek('"') ) return newString(parseString()); if( matchx("true" ) ) return con(1); @@ -1307,7 +1310,7 @@ public class Parser { if( instance(var) ) { Var selfVar = _scope.lookup("self"); Node self = liftExpr(_scope.in(selfVar),selfVar.type(),true); - return parsePostfixName(self,id); + return parsePostfixName(self,id,pre); } // Load local value @@ -1322,7 +1325,7 @@ public class Parser { else throw error("Cannot read uninitialized field '"+id+"'"); // Check for assign-update, x += e0; - char ch = _lexer.matchOperAssign(); + char ch = pre==0 ? _lexer.matchOperAssign() : (char)pre; if( ch==0 ) // Normal primary, check for postfix updates return parsePostfix(rvalue); // Assign-update direct into Scope @@ -1330,7 +1333,8 @@ public class Parser { throw error("Cannot reassign final '"+var._name+"'"); Node op = opAssign(ch,rvalue, var.type() ); _scope.update(var,op); - return postfix(ch) ? rvalue.unkeep() : op; + if( postfix(ch) ) rvalue.unkeep(); + return pre==0 && postfix(ch) ? rvalue : op; } // true if instance variable lookup (var is in any number of nested blocks, @@ -1573,14 +1577,16 @@ public class Parser { * expr ('[' expr ']')* [ [op]= expr ] // Array reference * </pre> */ - private Node parsePostfixName(Node expr, String name) { + private Node parsePostfixName(Node expr, String name) { return parsePostfixName(expr,name,0); } + + private Node parsePostfixName(Node expr, String name, int pre) { if( expr._type==Type.NIL ) throw error("Accessing unknown field '" + name + "' from 'null'"); // Sanity check expr for being a reference if( !(expr._type instanceof TypeMemPtr ptr) ) - return parseUnknownField(expr,name); + return parseUnknownField(expr,name,pre); // Find the field from the Type. Lookup in the base object field names. TypeMemPtr ptr2 = (TypeMemPtr)TYPES.get(ptr._obj._name); @@ -1588,7 +1594,7 @@ public class Parser { ptr = ptr.makeFrom(ptr2._obj); // The declaration fixes the field shape; retain this view's access. TypeStruct base = ptr._obj; int fidx = base.find(name); - if( fidx==-1 && base._open ) return parseUnknownField(expr,name); + if( fidx==-1 && base._open ) return parseUnknownField(expr,name,pre); if( fidx == -1 ) throw error("Accessing unknown field '" + name + "' from '" + ptr.str() + "'"); @@ -1609,7 +1615,7 @@ public class Parser { : off(base,name)).keep(); // Disambiguate "obj.fld==x" boolean test from "obj.fld=x" field assignment - if( matchOpx('=','=') ) { + if( pre==0 && matchOpx('=','=') ) { Node val = parseAsgn().keep(); Node lift = liftExpr( val, tf, false ); @@ -1628,14 +1634,16 @@ public class Parser { load = peep(load); // Check for assign-update, "ptr.fld += expr" or "ary[idx]++" - char ch = _lexer.matchOperAssign(); + char ch = pre==0 ? _lexer.matchOperAssign() : (char)pre; if( ch!=0 ) { Node op = opAssign(ch,load,tf); + // A narrow Store may drop its conversion; prefix still returns it. + if( pre!=0 ) op.keep(); store(name,f._alias,tf,expr.unkeep(),off.unkeep(),op,false,base.isAry() ? ctrl() : null); - load = postfix(ch) ? load.unkeep() : op; - // And use the original loaded value as the result - return load; - //throw Utils.TODO(); // NO POSTFIX AFTER STORE, JUST RETURN + if( pre!=0 ) op.unkeep(); + if( postfix(ch) ) load.unkeep(); + // Prefix returns the new value; postfix returns the old load. + return pre==0 && postfix(ch) ? load : op; } else { off.unkill(); // Method call: Loaded a function from a named field, AND the base @@ -1660,7 +1668,7 @@ public class Parser { // Syntax fixes the access even when a forward definition or a loop // leaves the receiver untyped. Resolve its alias and layout in the graph. - private Node parseUnknownField(Node expr, String name) { + private Node parseUnknownField(Node expr, String name, int pre) { expr.keep(); Node off = new FldOffNode(expr,name).peephole(); if( name.equals("[]") ) { @@ -1669,7 +1677,7 @@ public class Parser { off = peep(new AddNode(off,peep(new ShlNode(loc(),index,scale)))); } off.keep(); - if( matchOpx('=','=') ) { + if( pre==0 && matchOpx('=','=') ) { Node value = parseAsgn().keep(); Node st = new StoreNode(loc(),name,1,Type.BOTTOM,mem(),expr,off,value,false); st.setDef(0,ctrl()); @@ -1681,7 +1689,7 @@ public class Parser { Node load = new LoadNode(loc(),name,1,mem(),expr,off); load.setDef(0,ctrl()); load = peep(load); - char ch = _lexer.matchOperAssign(); + char ch = pre==0 ? _lexer.matchOperAssign() : (char)pre; if( ch!=0 ) { Node op = opAssign(ch,load,Type.BOTTOM).keep(); Node st = new StoreNode(loc(),name,1,Type.BOTTOM,mem(),expr,off,op,false); @@ -1691,7 +1699,7 @@ public class Parser { // the stored value after conversion; postfix returns the old load. // Reading our own Store folds once its alias and width are known. if( postfix(ch) ) load.unkeep(); - else { + if( pre!=0 || !postfix(ch) ) { load = new LoadNode(loc(),name,1,mem(),expr,off); load.setDef(0,ctrl()); load = peep(load); @@ -1701,7 +1709,7 @@ public class Parser { } else load.keep(); expr.unkill(); off.unkill(); - return parsePostfix(load.unkeep()); + return pre==0 ? parsePostfix(load.unkeep()) : load.unkeep(); } // zero/sign extend. "i" is limited to either classic unsigned (min==0) or |