mirror of
https://github.com/golang/go
synced 2024-11-23 00:40:08 -07:00
9761a6d069
(first step towards cleaner package handling) - check that map, function, and channel vars are pointers R=r OCL=13690 CL=13690
1936 lines
39 KiB
Go
1936 lines
39 KiB
Go
// Copyright 2009 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package Parser
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import Utils "utils"
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import Scanner "scanner"
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import Globals "globals"
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import Object "object"
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import Type "type"
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import Universe "universe"
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import Import "import"
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import AST "ast"
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export Parser
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type Parser struct {
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comp *Globals.Compilation;
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semantic_checks bool;
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verbose, indent int;
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S *Scanner.Scanner;
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// Token
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tok int; // one token look-ahead
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pos int; // token source position
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val string; // token value (for IDENT, NUMBER, STRING only)
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// Semantic analysis
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level int; // 0 = global scope, -1 = function/struct scope of global functions/structs, etc.
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top_scope *Globals.Scope;
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undef_types *Globals.List;
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exports *Globals.List;
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}
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// ----------------------------------------------------------------------------
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// Support functions
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func (P *Parser) PrintIndent() {
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for i := P.indent; i > 0; i-- {
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print ". ";
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}
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}
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func (P *Parser) Trace(msg string) {
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if P.verbose > 0 {
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P.PrintIndent();
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print msg, " {\n";
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P.indent++;
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}
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}
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func (P *Parser) Ecart() {
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if P.verbose > 0 {
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P.indent--;
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P.PrintIndent();
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print "}\n";
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}
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}
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func (P *Parser) Next() {
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P.tok, P.pos, P.val = P.S.Scan();
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if P.verbose > 1 {
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P.PrintIndent();
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print "[", P.pos, "] ", Scanner.TokenName(P.tok), "\n";
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}
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}
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func (P *Parser) Open(comp *Globals.Compilation, S *Scanner.Scanner) {
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P.comp = comp;
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P.semantic_checks = comp.flags.semantic_checks;
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P.verbose = comp.flags.verbose;
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P.indent = 0;
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P.S = S;
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P.Next();
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P.level = 0;
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P.top_scope = Universe.scope;
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P.undef_types = Globals.NewList();
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P.exports = Globals.NewList();
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}
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func (P *Parser) Error(pos int, msg string) {
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P.S.Error(pos, msg);
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}
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func (P *Parser) Expect(tok int) {
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if P.tok != tok {
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P.Error(P.pos, "expected '" + Scanner.TokenName(tok) + "', found '" + Scanner.TokenName(P.tok) + "'");
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}
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P.Next(); // make progress in any case
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}
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func (P *Parser) Optional(tok int) {
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if P.tok == tok {
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P.Next();
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}
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}
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// ----------------------------------------------------------------------------
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// Scopes
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func (P *Parser) OpenScope() {
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P.top_scope = Globals.NewScope(P.top_scope);
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}
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func (P *Parser) CloseScope() {
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P.top_scope = P.top_scope.parent;
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}
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func (P *Parser) Lookup(ident string) *Globals.Object {
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for scope := P.top_scope; scope != nil; scope = scope.parent {
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obj := scope.Lookup(ident);
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if obj != nil {
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return obj;
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}
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}
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return nil;
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}
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func (P *Parser) DeclareInScope(scope *Globals.Scope, obj *Globals.Object) {
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if !P.semantic_checks {
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return;
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}
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obj.pnolev = P.level;
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if scope.Lookup(obj.ident) != nil {
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P.Error(obj.pos, `"` + obj.ident + `" is declared already`);
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return; // don't insert it into the scope
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}
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scope.Insert(obj);
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}
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func (P *Parser) Declare(obj *Globals.Object) {
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P.DeclareInScope(P.top_scope, obj);
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}
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func MakeFunctionType(sig *Globals.Scope, p0, r0 int, check_recv bool) *Globals.Type {
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// Determine if we have a receiver or not.
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// TODO do we still need this?
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if p0 > 0 && check_recv {
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// method
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if p0 != 1 {
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panic "p0 != 1";
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}
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}
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typ := Globals.NewType(Type.FUNCTION);
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if p0 == 0 {
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typ.flags = 0;
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} else {
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typ.flags = Type.RECV;
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}
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typ.len_ = r0 - p0;
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typ.scope = sig;
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return typ;
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}
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func (P *Parser) DeclareFunc(ident string, typ *Globals.Type) *Globals.Object {
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// determine scope
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scope := P.top_scope;
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if typ.flags & Type.RECV != 0 {
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// method - declare in corresponding struct
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if typ.scope.entries.len_ < 1 {
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panic "no recv in signature?";
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}
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recv_typ := typ.scope.entries.first.obj.typ;
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if recv_typ.form == Type.POINTER {
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recv_typ = recv_typ.elt;
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}
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scope = recv_typ.scope;
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}
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// declare the function
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obj := scope.Lookup(ident);
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if obj == nil {
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obj = Globals.NewObject(-1, Object.FUNC, ident);
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obj.typ = typ;
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// TODO do we need to set the primary type? probably...
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P.DeclareInScope(scope, obj);
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return obj;
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}
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// obj != NULL: possibly a forward declaration.
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if (obj.kind != Object.FUNC) {
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P.Error(-1, `"` + ident + `" is declared already`);
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// Continue but do not insert this function into the scope.
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obj = Globals.NewObject(-1, Object.FUNC, ident);
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obj.typ = typ;
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// TODO do we need to set the prymary type? probably...
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return obj;
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}
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// We have a function with the same name.
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/*
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if (!EqualTypes(type, obj->type())) {
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this->Error("type of \"%s\" does not match its forward declaration", name.cstr());
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// Continue but do not insert this function into the scope.
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NewObject(Object::FUNC, name);
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obj->set_type(type);
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return obj;
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}
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*/
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// We have a matching forward declaration. Use it.
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return obj;
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}
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// ----------------------------------------------------------------------------
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// Common productions
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func (P *Parser) TryType() *Globals.Type;
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func (P *Parser) ParseExpression() Globals.Expr;
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func (P *Parser) TryStatement() bool;
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func (P *Parser) ParseDeclaration();
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func (P *Parser) ParseIdent() string {
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P.Trace("Ident");
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ident := "";
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if P.tok == Scanner.IDENT {
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ident = P.val;
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if P.verbose > 0 {
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P.PrintIndent();
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print "Ident = \"", ident, "\"\n";
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}
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P.Next();
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} else {
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P.Expect(Scanner.IDENT); // use Expect() error handling
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}
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P.Ecart();
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return ident;
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}
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func (P *Parser) ParseIdentDecl(kind int) *Globals.Object {
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P.Trace("IdentDecl");
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pos := P.pos;
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obj := Globals.NewObject(pos, kind, P.ParseIdent());
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P.Declare(obj);
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P.Ecart();
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return obj;
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}
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func (P *Parser) ParseIdentDeclList(kind int) *Globals.List {
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P.Trace("IdentDeclList");
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list := Globals.NewList();
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list.AddObj(P.ParseIdentDecl(kind));
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for P.tok == Scanner.COMMA {
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P.Next();
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list.AddObj(P.ParseIdentDecl(kind));
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}
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P.Ecart();
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return list;
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}
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func (P *Parser) ParseIdentList() {
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P.Trace("IdentList");
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P.ParseIdent();
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for P.tok == Scanner.COMMA {
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P.Next();
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P.ParseIdent();
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}
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P.Ecart();
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}
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func (P *Parser) ParseQualifiedIdent(pos int, ident string) *Globals.Object {
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P.Trace("QualifiedIdent");
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if pos < 0 {
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pos = P.pos;
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ident = P.ParseIdent();
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}
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if P.semantic_checks {
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obj := P.Lookup(ident);
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if obj == nil {
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P.Error(pos, `"` + ident + `" is not declared`);
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obj = Globals.NewObject(pos, Object.BAD, ident);
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}
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if obj.kind == Object.PACKAGE && P.tok == Scanner.PERIOD {
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if obj.pnolev < 0 {
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panic "obj.pnolev < 0";
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}
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pkg := P.comp.pkgs[obj.pnolev];
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//if pkg.obj.ident != ident {
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// panic "pkg.obj.ident != ident";
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//}
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P.Next(); // consume "."
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pos = P.pos;
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ident = P.ParseIdent();
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obj = pkg.scope.Lookup(ident);
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if obj == nil {
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P.Error(pos, `"` + ident + `" is not declared in package "` + pkg.obj.ident + `"`);
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obj = Globals.NewObject(pos, Object.BAD, ident);
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}
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}
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P.Ecart();
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return obj;
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} else {
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if P.tok == Scanner.PERIOD {
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P.Next();
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P.ParseIdent();
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}
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P.Ecart();
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return nil;
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}
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}
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// ----------------------------------------------------------------------------
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// Types
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func (P *Parser) ParseType() *Globals.Type {
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P.Trace("Type");
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typ := P.TryType();
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if typ == nil {
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P.Error(P.pos, "type expected");
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typ = Universe.bad_t;
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}
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P.Ecart();
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return typ;
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}
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func (P *Parser) ParseVarType() *Globals.Type {
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P.Trace("VarType");
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pos := P.pos;
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typ := P.ParseType();
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if P.semantic_checks {
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switch typ.form {
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case Type.ARRAY:
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if P.comp.flags.sixg || typ.len_ >= 0 {
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break;
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}
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// open arrays must be pointers
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fallthrough;
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case Type.MAP, Type.CHANNEL, Type.FUNCTION:
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P.Error(pos, "must be pointer to this type");
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typ = Universe.bad_t;
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}
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}
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P.Ecart();
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return typ;
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}
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func (P *Parser) ParseTypeName() *Globals.Type {
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P.Trace("TypeName");
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if P.semantic_checks {
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pos := P.pos;
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obj := P.ParseQualifiedIdent(-1, "");
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typ := obj.typ;
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if obj.kind != Object.TYPE {
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P.Error(pos, "qualified identifier does not denote a type");
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typ = Universe.bad_t;
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}
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P.Ecart();
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return typ;
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} else {
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P.ParseQualifiedIdent(-1, "");
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P.Ecart();
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return Universe.bad_t;
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}
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}
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func (P *Parser) ParseArrayType() *Globals.Type {
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P.Trace("ArrayType");
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P.Expect(Scanner.LBRACK);
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typ := Globals.NewType(Type.ARRAY);
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if P.tok != Scanner.RBRACK {
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// TODO set typ.len_
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P.ParseExpression();
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}
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P.Expect(Scanner.RBRACK);
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typ.elt = P.ParseVarType();
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P.Ecart();
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return typ;
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}
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func (P *Parser) ParseChannelType() *Globals.Type {
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P.Trace("ChannelType");
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P.Expect(Scanner.CHAN);
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typ := Globals.NewType(Type.CHANNEL);
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switch P.tok {
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case Scanner.SEND:
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typ.flags = Type.SEND;
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P.Next();
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case Scanner.RECV:
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typ.flags = Type.RECV;
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P.Next();
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default:
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typ.flags = Type.SEND + Type.RECV;
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}
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typ.elt = P.ParseVarType();
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P.Ecart();
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return typ;
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}
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func (P *Parser) ParseVarDeclList() {
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P.Trace("VarDeclList");
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list := P.ParseIdentDeclList(Object.VAR);
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typ := P.ParseVarType();
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for p := list.first; p != nil; p = p.next {
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p.obj.typ = typ; // TODO should use/have set_type()
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}
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P.Ecart();
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}
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func (P *Parser) ParseParameterSection() {
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P.Trace("ParameterSection");
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P.ParseVarDeclList();
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P.Ecart();
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}
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func (P *Parser) ParseParameterList() {
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P.Trace("ParameterList");
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P.ParseParameterSection();
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for P.tok == Scanner.COMMA {
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P.Next();
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P.ParseParameterSection();
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}
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P.Ecart();
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}
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func (P *Parser) ParseParameters() {
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P.Trace("Parameters");
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P.Expect(Scanner.LPAREN);
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if P.tok != Scanner.RPAREN {
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P.ParseParameterList();
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}
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P.Expect(Scanner.RPAREN);
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P.Ecart();
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}
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func (P *Parser) TryResult() bool {
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P.Trace("Result (try)");
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res := false;
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if P.tok == Scanner.LPAREN {
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// TODO: here we allow empty returns - should proably fix this
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P.ParseParameters();
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res = true;
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} else {
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res = P.TryType() != nil;
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}
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P.Ecart();
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return res;
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}
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// Anonymous signatures
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//
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// (params)
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// (params) type
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// (params) (results)
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// (recv) . (params)
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// (recv) . (params) type
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// (recv) . (params) (results)
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func (P *Parser) ParseAnonymousSignature() *Globals.Type {
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P.Trace("AnonymousSignature");
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P.OpenScope();
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P.level--;
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sig := P.top_scope;
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p0 := 0;
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recv_pos := P.pos;
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P.ParseParameters();
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if P.tok == Scanner.PERIOD {
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p0 = sig.entries.len_;
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if (P.semantic_checks && p0 != 1) {
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P.Error(recv_pos, "must have exactly one receiver")
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panic "UNIMPLEMENTED (ParseAnonymousSignature)";
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// TODO do something useful here
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}
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P.Next();
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P.ParseParameters();
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}
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r0 := sig.entries.len_;
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P.TryResult();
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P.level++;
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P.CloseScope();
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P.Ecart();
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return MakeFunctionType(sig, p0, r0, true);
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}
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// Named signatures
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//
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// name (params)
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// name (params) type
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// name (params) (results)
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// (recv) name (params)
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// (recv) name (params) type
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// (recv) name (params) (results)
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func (P *Parser) ParseNamedSignature() (name string, typ *Globals.Type) {
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P.Trace("NamedSignature");
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P.OpenScope();
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P.level--;
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sig := P.top_scope;
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p0 := 0;
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if P.tok == Scanner.LPAREN {
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recv_pos := P.pos;
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P.ParseParameters();
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p0 = sig.entries.len_;
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if (P.semantic_checks && p0 != 1) {
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print "p0 = ", p0, "\n";
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P.Error(recv_pos, "must have exactly one receiver")
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panic "UNIMPLEMENTED (ParseNamedSignature)";
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// TODO do something useful here
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}
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}
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name = P.ParseIdent();
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P.ParseParameters();
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r0 := sig.entries.len_;
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P.TryResult();
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P.level++;
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P.CloseScope();
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P.Ecart();
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return name, MakeFunctionType(sig, p0, r0, true);
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}
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func (P *Parser) ParseFunctionType() *Globals.Type {
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P.Trace("FunctionType");
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P.Expect(Scanner.FUNC);
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typ := P.ParseAnonymousSignature();
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P.Ecart();
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return typ;
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}
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func (P *Parser) ParseMethodDecl() {
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P.Trace("MethodDecl");
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pos := P.pos;
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ident := P.ParseIdent();
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P.OpenScope();
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P.level--;
|
|
sig := P.top_scope;
|
|
// dummy receiver (give it a name so it won't conflict with unnamed result)
|
|
sig.Insert(Globals.NewObject(pos, Object.VAR, ".recv"));
|
|
P.ParseParameters();
|
|
r0 := sig.entries.len_;
|
|
P.TryResult();
|
|
P.level++;
|
|
P.CloseScope();
|
|
P.Optional(Scanner.SEMICOLON);
|
|
|
|
obj := Globals.NewObject(pos, Object.FUNC, ident);
|
|
obj.typ = MakeFunctionType(sig, 1, r0, true);
|
|
P.Declare(obj);
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseInterfaceType() *Globals.Type {
|
|
P.Trace("InterfaceType");
|
|
|
|
P.Expect(Scanner.INTERFACE);
|
|
P.Expect(Scanner.LBRACE);
|
|
P.OpenScope();
|
|
P.level--;
|
|
typ := Globals.NewType(Type.INTERFACE);
|
|
typ.scope = P.top_scope;
|
|
for P.tok == Scanner.IDENT {
|
|
P.ParseMethodDecl();
|
|
}
|
|
P.level++;
|
|
P.CloseScope();
|
|
P.Expect(Scanner.RBRACE);
|
|
|
|
P.Ecart();
|
|
return typ;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseMapType() *Globals.Type {
|
|
P.Trace("MapType");
|
|
|
|
P.Expect(Scanner.MAP);
|
|
P.Expect(Scanner.LBRACK);
|
|
typ := Globals.NewType(Type.MAP);
|
|
typ.key = P.ParseVarType();
|
|
P.Expect(Scanner.RBRACK);
|
|
typ.elt = P.ParseVarType();
|
|
P.Ecart();
|
|
|
|
return typ;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseFieldDecl() {
|
|
P.Trace("FieldDecl");
|
|
P.ParseVarDeclList();
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseStructType() *Globals.Type {
|
|
P.Trace("StructType");
|
|
|
|
P.Expect(Scanner.STRUCT);
|
|
P.Expect(Scanner.LBRACE);
|
|
P.OpenScope();
|
|
P.level--;
|
|
typ := Globals.NewType(Type.STRUCT);
|
|
typ.scope = P.top_scope;
|
|
for P.tok == Scanner.IDENT {
|
|
P.ParseFieldDecl();
|
|
if P.tok != Scanner.RBRACE {
|
|
P.Expect(Scanner.SEMICOLON);
|
|
}
|
|
}
|
|
P.Optional(Scanner.SEMICOLON);
|
|
P.level++;
|
|
P.CloseScope();
|
|
P.Expect(Scanner.RBRACE);
|
|
|
|
P.Ecart();
|
|
return typ;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParsePointerType() *Globals.Type {
|
|
P.Trace("PointerType");
|
|
|
|
P.Expect(Scanner.MUL);
|
|
typ := Globals.NewType(Type.POINTER);
|
|
|
|
if P.semantic_checks {
|
|
if P.tok == Scanner.IDENT {
|
|
if P.Lookup(P.val) == nil {
|
|
// implicit forward declaration
|
|
// TODO very problematic: in which scope should the
|
|
// type object be declared? It's different if this
|
|
// is inside a struct or say in a var declaration.
|
|
// This code is only here for "compatibility" with 6g.
|
|
pos := P.pos;
|
|
obj := Globals.NewObject(pos, Object.TYPE, P.ParseIdent());
|
|
obj.typ = Globals.NewType(Type.UNDEF);
|
|
obj.typ.obj = obj; // primary type object
|
|
typ.elt = obj.typ;
|
|
// TODO obj should be declared, but scope is not clear
|
|
} else {
|
|
// type name
|
|
// (ParseType() doesn't permit incomplete types,
|
|
// so call ParseTypeName() here)
|
|
typ.elt = P.ParseTypeName();
|
|
}
|
|
} else {
|
|
typ.elt = P.ParseType();
|
|
}
|
|
|
|
// collect undefined pointer types
|
|
if typ.elt.form == Type.UNDEF {
|
|
P.undef_types.AddTyp(typ);
|
|
}
|
|
|
|
} else {
|
|
typ.elt = P.ParseType();
|
|
}
|
|
|
|
P.Ecart();
|
|
return typ;
|
|
}
|
|
|
|
|
|
// Returns nil if no type was found.
|
|
func (P *Parser) TryType() *Globals.Type {
|
|
P.Trace("Type (try)");
|
|
|
|
pos := P.pos;
|
|
var typ *Globals.Type = nil;
|
|
switch P.tok {
|
|
case Scanner.IDENT: typ = P.ParseTypeName();
|
|
case Scanner.LBRACK: typ = P.ParseArrayType();
|
|
case Scanner.CHAN: typ = P.ParseChannelType();
|
|
case Scanner.INTERFACE: typ = P.ParseInterfaceType();
|
|
case Scanner.FUNC: typ = P.ParseFunctionType();
|
|
case Scanner.MAP: typ = P.ParseMapType();
|
|
case Scanner.STRUCT: typ = P.ParseStructType();
|
|
case Scanner.MUL: typ = P.ParsePointerType();
|
|
}
|
|
|
|
if typ != nil && typ.form == Type.UNDEF {
|
|
P.Error(pos, "incomplete type");
|
|
}
|
|
|
|
P.Ecart();
|
|
return typ;
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Blocks
|
|
|
|
func (P *Parser) ParseStatement() {
|
|
P.Trace("Statement");
|
|
if !P.TryStatement() {
|
|
P.Error(P.pos, "statement expected");
|
|
P.Next(); // make progress
|
|
}
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseStatementList() {
|
|
P.Trace("StatementList");
|
|
for P.TryStatement() {
|
|
P.Optional(Scanner.SEMICOLON);
|
|
}
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseBlock(sig *Globals.Scope) {
|
|
P.Trace("Block");
|
|
|
|
P.Expect(Scanner.LBRACE);
|
|
P.OpenScope();
|
|
if sig != nil {
|
|
P.level--;
|
|
// add copies of the formal parameters to the function scope
|
|
scope := P.top_scope;
|
|
for p := sig.entries.first; p != nil; p = p.next {
|
|
scope.Insert(p.obj.Copy())
|
|
}
|
|
}
|
|
if P.tok != Scanner.RBRACE && P.tok != Scanner.SEMICOLON {
|
|
P.ParseStatementList();
|
|
}
|
|
P.Optional(Scanner.SEMICOLON);
|
|
if sig != nil {
|
|
P.level++;
|
|
}
|
|
P.CloseScope();
|
|
P.Expect(Scanner.RBRACE);
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Expressions
|
|
|
|
func (P *Parser) ParseExpressionList() *Globals.List {
|
|
P.Trace("ExpressionList");
|
|
|
|
list := Globals.NewList();
|
|
P.ParseExpression();
|
|
list.AddInt(0); // TODO fix this - add correct list element
|
|
for P.tok == Scanner.COMMA {
|
|
P.Next();
|
|
P.ParseExpression();
|
|
list.AddInt(0); // TODO fix this - add correct list element
|
|
}
|
|
|
|
P.Ecart();
|
|
return list;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseNew() Globals.Expr {
|
|
P.Trace("New");
|
|
|
|
P.Expect(Scanner.NEW);
|
|
P.Expect(Scanner.LPAREN);
|
|
P.ParseType();
|
|
if P.tok == Scanner.COMMA {
|
|
P.Next();
|
|
P.ParseExpressionList()
|
|
}
|
|
P.Expect(Scanner.RPAREN);
|
|
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseFunctionLit() Globals.Expr {
|
|
P.Trace("FunctionLit");
|
|
|
|
typ := P.ParseFunctionType();
|
|
P.ParseBlock(typ.scope);
|
|
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseExpressionPair() {
|
|
P.Trace("ExpressionPair");
|
|
|
|
P.ParseExpression();
|
|
P.Expect(Scanner.COLON);
|
|
P.ParseExpression();
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseExpressionPairList() {
|
|
P.Trace("ExpressionPairList");
|
|
|
|
P.ParseExpressionPair();
|
|
for (P.tok == Scanner.COMMA) {
|
|
P.ParseExpressionPair();
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseBuiltinCall() Globals.Expr {
|
|
P.Trace("BuiltinCall");
|
|
|
|
P.ParseExpressionList(); // TODO should be optional
|
|
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseCompositeLit(typ *Globals.Type) Globals.Expr {
|
|
P.Trace("CompositeLit");
|
|
|
|
// TODO I think we should use {} instead of () for
|
|
// composite literals to syntactically distinguish
|
|
// them from conversions. For now: allow both.
|
|
var paren int;
|
|
if P.tok == Scanner.LPAREN {
|
|
P.Next();
|
|
paren = Scanner.RPAREN;
|
|
} else {
|
|
P.Expect(Scanner.LBRACE);
|
|
paren = Scanner.RBRACE;
|
|
}
|
|
|
|
// TODO: should allow trailing ','
|
|
if P.tok != paren {
|
|
P.ParseExpression();
|
|
if P.tok == Scanner.COMMA {
|
|
P.Next();
|
|
if P.tok != paren {
|
|
P.ParseExpressionList();
|
|
}
|
|
} else if P.tok == Scanner.COLON {
|
|
P.Next();
|
|
P.ParseExpression();
|
|
if P.tok == Scanner.COMMA {
|
|
P.Next();
|
|
if P.tok != paren {
|
|
P.ParseExpressionPairList();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
P.Expect(paren);
|
|
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseOperand(pos int, ident string) Globals.Expr {
|
|
P.Trace("Operand");
|
|
|
|
if pos < 0 && P.tok == Scanner.IDENT {
|
|
// no look-ahead yet
|
|
pos = P.pos;
|
|
ident = P.val;
|
|
P.Next();
|
|
}
|
|
|
|
if pos >= 0 {
|
|
// TODO set these up properly in the Universe
|
|
if ident == "panic" || ident == "print" {
|
|
P.ParseBuiltinCall();
|
|
goto exit;
|
|
}
|
|
|
|
P.ParseQualifiedIdent(pos, ident);
|
|
// TODO enable code below
|
|
/*
|
|
if obj.kind == Object.TYPE {
|
|
P.ParseCompositeLit(obj.typ);
|
|
}
|
|
*/
|
|
goto exit;
|
|
}
|
|
|
|
switch P.tok {
|
|
case Scanner.IDENT:
|
|
panic "UNREACHABLE";
|
|
case Scanner.LPAREN:
|
|
P.Next();
|
|
P.ParseExpression();
|
|
P.Expect(Scanner.RPAREN);
|
|
case Scanner.STRING: fallthrough;
|
|
case Scanner.NUMBER: fallthrough;
|
|
case Scanner.NIL: fallthrough;
|
|
case Scanner.IOTA: fallthrough;
|
|
case Scanner.TRUE: fallthrough;
|
|
case Scanner.FALSE:
|
|
P.Next();
|
|
case Scanner.FUNC:
|
|
P.ParseFunctionLit();
|
|
case Scanner.NEW:
|
|
P.ParseNew();
|
|
default:
|
|
typ := P.TryType();
|
|
if typ != nil {
|
|
P.ParseCompositeLit(typ);
|
|
} else {
|
|
P.Error(P.pos, "operand expected");
|
|
P.Next(); // make progress
|
|
}
|
|
}
|
|
|
|
exit:
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseSelectorOrTypeAssertion() Globals.Expr {
|
|
P.Trace("SelectorOrTypeAssertion");
|
|
|
|
P.Expect(Scanner.PERIOD);
|
|
if P.tok == Scanner.IDENT {
|
|
P.ParseIdent();
|
|
} else {
|
|
P.Expect(Scanner.LPAREN);
|
|
P.ParseType();
|
|
P.Expect(Scanner.RPAREN);
|
|
}
|
|
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseIndexOrSlice() Globals.Expr {
|
|
P.Trace("IndexOrSlice");
|
|
|
|
P.Expect(Scanner.LBRACK);
|
|
P.ParseExpression();
|
|
if P.tok == Scanner.COLON {
|
|
P.Next();
|
|
P.ParseExpression();
|
|
}
|
|
P.Expect(Scanner.RBRACK);
|
|
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseCall() Globals.Expr {
|
|
P.Trace("Call");
|
|
|
|
P.Expect(Scanner.LPAREN);
|
|
if P.tok != Scanner.RPAREN {
|
|
P.ParseExpressionList();
|
|
}
|
|
P.Expect(Scanner.RPAREN);
|
|
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParsePrimaryExpr(pos int, ident string) Globals.Expr {
|
|
P.Trace("PrimaryExpr");
|
|
|
|
P.ParseOperand(pos, ident);
|
|
for {
|
|
switch P.tok {
|
|
case Scanner.PERIOD:
|
|
P.ParseSelectorOrTypeAssertion();
|
|
case Scanner.LBRACK:
|
|
P.ParseIndexOrSlice();
|
|
case Scanner.LPAREN:
|
|
P.ParseCall();
|
|
default:
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
}
|
|
|
|
P.Ecart();
|
|
return nil;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParsePrimaryExprList() {
|
|
P.Trace("PrimaryExprList");
|
|
|
|
P.ParsePrimaryExpr(-1, "");
|
|
for P.tok == Scanner.COMMA {
|
|
P.Next();
|
|
P.ParsePrimaryExpr(-1, "");
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseUnaryExpr() Globals.Expr {
|
|
P.Trace("UnaryExpr");
|
|
|
|
switch P.tok {
|
|
case Scanner.ADD: fallthrough;
|
|
case Scanner.SUB: fallthrough;
|
|
case Scanner.NOT: fallthrough;
|
|
case Scanner.XOR: fallthrough;
|
|
case Scanner.MUL: fallthrough;
|
|
case Scanner.RECV: fallthrough;
|
|
case Scanner.AND:
|
|
P.Next();
|
|
P.ParseUnaryExpr();
|
|
P.Ecart();
|
|
return nil; // TODO fix this
|
|
}
|
|
P.ParsePrimaryExpr(-1, "");
|
|
|
|
P.Ecart();
|
|
return nil; // TODO fix this
|
|
}
|
|
|
|
|
|
func Precedence(tok int) int {
|
|
// TODO should use a map or array here for lookup
|
|
switch tok {
|
|
case Scanner.LOR:
|
|
return 1;
|
|
case Scanner.LAND:
|
|
return 2;
|
|
case Scanner.SEND, Scanner.RECV:
|
|
return 3;
|
|
case Scanner.EQL, Scanner.NEQ, Scanner.LSS, Scanner.LEQ, Scanner.GTR, Scanner.GEQ:
|
|
return 4;
|
|
case Scanner.ADD, Scanner.SUB, Scanner.OR, Scanner.XOR:
|
|
return 5;
|
|
case Scanner.MUL, Scanner.QUO, Scanner.REM, Scanner.SHL, Scanner.SHR, Scanner.AND:
|
|
return 6;
|
|
}
|
|
return 0;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseBinaryExpr(pos int, ident string, prec1 int) Globals.Expr {
|
|
P.Trace("BinaryExpr");
|
|
|
|
var x Globals.Expr;
|
|
if pos >= 0 {
|
|
x = P.ParsePrimaryExpr(pos, ident);
|
|
} else {
|
|
x = P.ParseUnaryExpr();
|
|
}
|
|
for prec := Precedence(P.tok); prec >= prec1; prec-- {
|
|
for Precedence(P.tok) == prec {
|
|
e := new(AST.BinaryExpr);
|
|
e.typ_ = Universe.undef_t; // TODO fix this
|
|
e.op = P.tok; // TODO should we use tokens or separate operator constants?
|
|
e.x = x;
|
|
P.Next();
|
|
e.y = P.ParseBinaryExpr(-1, "", prec + 1);
|
|
x = e;
|
|
}
|
|
}
|
|
|
|
P.Ecart();
|
|
return x;
|
|
}
|
|
|
|
|
|
// Expressions where the first token may be an identifier which has already
|
|
// been consumed. If the identifier is present, pos is the identifier position,
|
|
// otherwise pos must be < 0 (and ident is ignored).
|
|
func (P *Parser) ParseIdentExpression(pos int, ident string) Globals.Expr {
|
|
P.Trace("IdentExpression");
|
|
indent := P.indent;
|
|
|
|
x := P.ParseBinaryExpr(pos, ident, 1);
|
|
|
|
if indent != P.indent {
|
|
panic "imbalanced tracing code (Expression)";
|
|
}
|
|
P.Ecart();
|
|
return x;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseExpression() Globals.Expr {
|
|
P.Trace("Expression");
|
|
|
|
x := P.ParseIdentExpression(-1, "");
|
|
|
|
P.Ecart();
|
|
return x;
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Statements
|
|
|
|
func (P *Parser) ConvertToExprList(pos_list, ident_list, expr_list *Globals.List) {
|
|
for p, q := pos_list.first, ident_list.first; q != nil; p, q = p.next, q.next {
|
|
pos, ident := p.val, q.str;
|
|
if P.semantic_checks {
|
|
obj := P.Lookup(ident);
|
|
if obj == nil {
|
|
P.Error(pos, `"` + ident + `" is not declared`);
|
|
obj = Globals.NewObject(pos, Object.BAD, ident);
|
|
}
|
|
}
|
|
expr_list.AddInt(0); // TODO fix this - add correct expression
|
|
}
|
|
ident_list.Clear();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseIdentOrExpr(pos_list, ident_list, expr_list *Globals.List) {
|
|
P.Trace("IdentOrExpr");
|
|
|
|
pos_list.AddInt(P.pos);
|
|
pos, ident := -1, "";
|
|
just_ident := false;
|
|
if expr_list.len_ == 0 /* only idents so far */ && P.tok == Scanner.IDENT {
|
|
pos, ident = P.pos, P.val;
|
|
P.Next();
|
|
switch P.tok {
|
|
case Scanner.COMMA,
|
|
Scanner.COLON,
|
|
Scanner.DEFINE,
|
|
Scanner.ASSIGN,
|
|
Scanner.ADD_ASSIGN,
|
|
Scanner.SUB_ASSIGN,
|
|
Scanner.MUL_ASSIGN,
|
|
Scanner.QUO_ASSIGN,
|
|
Scanner.REM_ASSIGN,
|
|
Scanner.AND_ASSIGN,
|
|
Scanner.OR_ASSIGN,
|
|
Scanner.XOR_ASSIGN,
|
|
Scanner.SHL_ASSIGN,
|
|
Scanner.SHR_ASSIGN:
|
|
// identifier is not part of a more complicated expression
|
|
just_ident = true;
|
|
}
|
|
}
|
|
|
|
if just_ident {
|
|
ident_list.AddStr(ident);
|
|
} else {
|
|
P.ConvertToExprList(pos_list, ident_list, expr_list);
|
|
P.ParseIdentExpression(pos, ident);
|
|
expr_list.AddInt(0); // TODO fix this - add correct expression
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseIdentOrExprList() (pos_list, ident_list, expr_list *Globals.List) {
|
|
P.Trace("IdentOrExprList");
|
|
|
|
pos_list, ident_list, expr_list = Globals.NewList(), Globals.NewList(), Globals.NewList();
|
|
P.ParseIdentOrExpr(pos_list, ident_list, expr_list);
|
|
for P.tok == Scanner.COMMA {
|
|
P.Next();
|
|
P.ParseIdentOrExpr(pos_list, ident_list, expr_list);
|
|
}
|
|
|
|
P.Ecart();
|
|
return pos_list, ident_list, expr_list;
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseSimpleStat() {
|
|
P.Trace("SimpleStat");
|
|
|
|
// If we see an identifier, we don't know if it's part of a
|
|
// label declaration, (multiple) variable declaration, assignment,
|
|
// or simply an expression, without looking ahead.
|
|
// Strategy: We parse an expression list, but simultaneously, as
|
|
// long as possible, maintain a list of identifiers which is converted
|
|
// into an expression list only if neccessary. The result of
|
|
// ParseIdentOrExprList is a list of ident/expr positions and either
|
|
// a non-empty list of identifiers or a non-empty list of expressions
|
|
// (but not both).
|
|
pos_list, ident_list, expr_list := P.ParseIdentOrExprList();
|
|
|
|
switch P.tok {
|
|
case Scanner.COLON:
|
|
// label declaration
|
|
if P.semantic_checks && ident_list.len_ != 1 {
|
|
P.Error(P.pos, "illegal label declaration");
|
|
}
|
|
P.Next();
|
|
|
|
case Scanner.DEFINE:
|
|
// variable declaration
|
|
if P.semantic_checks && ident_list.len_ == 0 {
|
|
P.Error(P.pos, "illegal left-hand side for declaration");
|
|
}
|
|
P.Next();
|
|
pos := P.pos;
|
|
val_list := P.ParseExpressionList();
|
|
if P.semantic_checks && val_list.len_ != ident_list.len_ {
|
|
P.Error(pos, "number of expressions does not match number of variables");
|
|
}
|
|
// declare variables
|
|
if P.semantic_checks {
|
|
for p, q := pos_list.first, ident_list.first; q != nil; p, q = p.next, q.next {
|
|
obj := Globals.NewObject(p.val, Object.VAR, q.str);
|
|
P.Declare(obj);
|
|
// TODO set correct types
|
|
}
|
|
}
|
|
|
|
case Scanner.ASSIGN: fallthrough;
|
|
case Scanner.ADD_ASSIGN: fallthrough;
|
|
case Scanner.SUB_ASSIGN: fallthrough;
|
|
case Scanner.MUL_ASSIGN: fallthrough;
|
|
case Scanner.QUO_ASSIGN: fallthrough;
|
|
case Scanner.REM_ASSIGN: fallthrough;
|
|
case Scanner.AND_ASSIGN: fallthrough;
|
|
case Scanner.OR_ASSIGN: fallthrough;
|
|
case Scanner.XOR_ASSIGN: fallthrough;
|
|
case Scanner.SHL_ASSIGN: fallthrough;
|
|
case Scanner.SHR_ASSIGN:
|
|
P.ConvertToExprList(pos_list, ident_list, expr_list);
|
|
P.Next();
|
|
pos := P.pos;
|
|
val_list := P.ParseExpressionList();
|
|
if P.semantic_checks && val_list.len_ != expr_list.len_ {
|
|
P.Error(pos, "number of expressions does not match number of variables");
|
|
}
|
|
|
|
default:
|
|
P.ConvertToExprList(pos_list, ident_list, expr_list);
|
|
if P.semantic_checks && expr_list.len_ != 1 {
|
|
P.Error(P.pos, "no expression list allowed");
|
|
}
|
|
if P.tok == Scanner.INC || P.tok == Scanner.DEC {
|
|
P.Next();
|
|
}
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseGoStat() {
|
|
P.Trace("GoStat");
|
|
|
|
P.Expect(Scanner.GO);
|
|
P.ParseExpression();
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseReturnStat() {
|
|
P.Trace("ReturnStat");
|
|
|
|
P.Expect(Scanner.RETURN);
|
|
if P.tok != Scanner.SEMICOLON && P.tok != Scanner.RBRACE {
|
|
P.ParseExpressionList();
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseControlFlowStat(tok int) {
|
|
P.Trace("ControlFlowStat");
|
|
|
|
P.Expect(tok);
|
|
if P.tok == Scanner.IDENT {
|
|
P.ParseIdent();
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseIfStat() *AST.IfStat {
|
|
P.Trace("IfStat");
|
|
|
|
P.Expect(Scanner.IF);
|
|
P.OpenScope();
|
|
if P.tok != Scanner.LBRACE {
|
|
if P.tok != Scanner.SEMICOLON {
|
|
P.ParseSimpleStat();
|
|
}
|
|
if P.tok == Scanner.SEMICOLON {
|
|
P.Next();
|
|
if P.tok != Scanner.LBRACE {
|
|
P.ParseExpression();
|
|
}
|
|
}
|
|
}
|
|
P.ParseBlock(nil);
|
|
if P.tok == Scanner.ELSE {
|
|
P.Next();
|
|
if P.tok == Scanner.IF {
|
|
P.ParseIfStat();
|
|
} else {
|
|
// TODO should be P.ParseBlock()
|
|
P.ParseStatement();
|
|
}
|
|
}
|
|
P.CloseScope();
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseForStat() {
|
|
P.Trace("ForStat");
|
|
|
|
P.Expect(Scanner.FOR);
|
|
P.OpenScope();
|
|
if P.tok != Scanner.LBRACE {
|
|
if P.tok != Scanner.SEMICOLON {
|
|
P.ParseSimpleStat();
|
|
}
|
|
if P.tok == Scanner.SEMICOLON {
|
|
P.Next();
|
|
if P.tok != Scanner.SEMICOLON {
|
|
P.ParseExpression();
|
|
}
|
|
P.Expect(Scanner.SEMICOLON);
|
|
if P.tok != Scanner.LBRACE {
|
|
P.ParseSimpleStat();
|
|
}
|
|
}
|
|
}
|
|
P.ParseBlock(nil);
|
|
P.CloseScope();
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseCase() {
|
|
P.Trace("Case");
|
|
|
|
if P.tok == Scanner.CASE {
|
|
P.Next();
|
|
P.ParseExpressionList();
|
|
} else {
|
|
P.Expect(Scanner.DEFAULT);
|
|
}
|
|
P.Expect(Scanner.COLON);
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseCaseList() {
|
|
P.Trace("CaseList");
|
|
|
|
P.ParseCase();
|
|
for P.tok == Scanner.CASE || P.tok == Scanner.DEFAULT {
|
|
P.ParseCase();
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseCaseClause() {
|
|
P.Trace("CaseClause");
|
|
|
|
P.ParseCaseList();
|
|
if P.tok != Scanner.FALLTHROUGH && P.tok != Scanner.RBRACE {
|
|
P.ParseStatementList();
|
|
P.Optional(Scanner.SEMICOLON);
|
|
}
|
|
if P.tok == Scanner.FALLTHROUGH {
|
|
P.Next();
|
|
P.Optional(Scanner.SEMICOLON);
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseSwitchStat() {
|
|
P.Trace("SwitchStat");
|
|
|
|
P.Expect(Scanner.SWITCH);
|
|
P.OpenScope();
|
|
if P.tok != Scanner.LBRACE {
|
|
if P.tok != Scanner.SEMICOLON {
|
|
P.ParseSimpleStat();
|
|
}
|
|
if P.tok == Scanner.SEMICOLON {
|
|
P.Next();
|
|
if P.tok != Scanner.LBRACE {
|
|
P.ParseExpression();
|
|
}
|
|
}
|
|
}
|
|
P.Expect(Scanner.LBRACE);
|
|
for P.tok == Scanner.CASE || P.tok == Scanner.DEFAULT {
|
|
P.ParseCaseClause();
|
|
}
|
|
P.Expect(Scanner.RBRACE);
|
|
P.CloseScope();
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseCommCase() {
|
|
P.Trace("CommCase");
|
|
|
|
if P.tok == Scanner.CASE {
|
|
P.Next();
|
|
if P.tok == Scanner.GTR {
|
|
// send
|
|
P.Next();
|
|
P.ParseExpression();
|
|
P.Expect(Scanner.EQL);
|
|
P.ParseExpression();
|
|
} else {
|
|
// receive
|
|
if P.tok != Scanner.LSS {
|
|
P.ParseIdent();
|
|
P.Expect(Scanner.ASSIGN);
|
|
}
|
|
P.Expect(Scanner.LSS);
|
|
P.ParseExpression();
|
|
}
|
|
} else {
|
|
P.Expect(Scanner.DEFAULT);
|
|
}
|
|
P.Expect(Scanner.COLON);
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseCommClause() {
|
|
P.Trace("CommClause");
|
|
|
|
P.ParseCommCase();
|
|
if P.tok != Scanner.CASE && P.tok != Scanner.DEFAULT && P.tok != Scanner.RBRACE {
|
|
P.ParseStatementList();
|
|
P.Optional(Scanner.SEMICOLON);
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseRangeStat() bool {
|
|
P.Trace("RangeStat");
|
|
|
|
P.Expect(Scanner.RANGE);
|
|
P.ParseIdentList();
|
|
P.Expect(Scanner.DEFINE);
|
|
P.ParseExpression();
|
|
P.ParseBlock(nil);
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseSelectStat() bool {
|
|
P.Trace("SelectStat");
|
|
|
|
P.Expect(Scanner.SELECT);
|
|
P.Expect(Scanner.LBRACE);
|
|
for P.tok != Scanner.RBRACE && P.tok != Scanner.EOF {
|
|
P.ParseCommClause();
|
|
}
|
|
P.Next();
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) TryStatement() bool {
|
|
P.Trace("Statement (try)");
|
|
indent := P.indent;
|
|
|
|
res := true;
|
|
switch P.tok {
|
|
case Scanner.CONST: fallthrough;
|
|
case Scanner.TYPE: fallthrough;
|
|
case Scanner.VAR:
|
|
P.ParseDeclaration();
|
|
case Scanner.FUNC:
|
|
// for now we do not allow local function declarations
|
|
fallthrough;
|
|
case Scanner.MUL, Scanner.SEND, Scanner.RECV, Scanner.IDENT, Scanner.LPAREN:
|
|
P.ParseSimpleStat();
|
|
case Scanner.GO:
|
|
P.ParseGoStat();
|
|
case Scanner.RETURN:
|
|
P.ParseReturnStat();
|
|
case Scanner.BREAK, Scanner.CONTINUE, Scanner.GOTO:
|
|
P.ParseControlFlowStat(P.tok);
|
|
case Scanner.LBRACE:
|
|
P.ParseBlock(nil);
|
|
case Scanner.IF:
|
|
P.ParseIfStat();
|
|
case Scanner.FOR:
|
|
P.ParseForStat();
|
|
case Scanner.SWITCH:
|
|
P.ParseSwitchStat();
|
|
case Scanner.RANGE:
|
|
P.ParseRangeStat();
|
|
case Scanner.SELECT:
|
|
P.ParseSelectStat();
|
|
default:
|
|
// no statement found
|
|
res = false;
|
|
}
|
|
|
|
if indent != P.indent {
|
|
panic "imbalanced tracing code (Statement)"
|
|
}
|
|
P.Ecart();
|
|
return res;
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Declarations
|
|
|
|
func (P *Parser) ParseImportSpec() {
|
|
P.Trace("ImportSpec");
|
|
|
|
var obj *Globals.Object = nil;
|
|
if P.tok == Scanner.PERIOD {
|
|
P.Error(P.pos, `"import ." not yet handled properly`);
|
|
P.Next();
|
|
} else if P.tok == Scanner.IDENT {
|
|
obj = P.ParseIdentDecl(Object.PACKAGE);
|
|
}
|
|
|
|
if (P.semantic_checks && P.tok == Scanner.STRING) {
|
|
// TODO eventually the scanner should strip the quotes
|
|
pkg_name := P.val[1 : len(P.val) - 1]; // strip quotes
|
|
pkg := Import.Import(P.comp, pkg_name);
|
|
if pkg != nil {
|
|
pno := pkg.obj.pnolev; // preserve pno
|
|
if obj == nil {
|
|
// use original package name
|
|
obj = pkg.obj;
|
|
P.Declare(obj); // this changes (pkg.)obj.pnolev!
|
|
}
|
|
obj.pnolev = pno; // correct pno
|
|
} else {
|
|
P.Error(P.pos, `import of "` + pkg_name + `" failed`);
|
|
}
|
|
P.Next();
|
|
} else {
|
|
P.Expect(Scanner.STRING); // use Expect() error handling
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseConstSpec(exported bool) {
|
|
P.Trace("ConstSpec");
|
|
|
|
list := P.ParseIdentDeclList(Object.CONST);
|
|
typ := P.TryType();
|
|
if typ != nil {
|
|
for p := list.first; p != nil; p = p.next {
|
|
p.obj.exported = exported;
|
|
p.obj.typ = typ; // TODO should use/have set_type()!
|
|
}
|
|
}
|
|
if P.tok == Scanner.ASSIGN {
|
|
P.Next();
|
|
P.ParseExpressionList();
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseTypeSpec(exported bool) {
|
|
P.Trace("TypeSpec");
|
|
|
|
pos := P.pos;
|
|
ident := P.ParseIdent();
|
|
obj := P.top_scope.Lookup(ident); // only lookup in top scope!
|
|
if obj != nil {
|
|
// name already declared - ok if forward declared type
|
|
if obj.kind != Object.TYPE || obj.typ.form != Type.UNDEF {
|
|
// TODO use obj.pos to refer to decl pos in error msg!
|
|
P.Error(pos, `"` + ident + `" is declared already`);
|
|
}
|
|
} else {
|
|
obj = Globals.NewObject(pos, Object.TYPE, ident);
|
|
obj.exported = exported;
|
|
obj.typ = Globals.NewType(Type.UNDEF);
|
|
obj.typ.obj = obj; // primary type object
|
|
P.Declare(obj);
|
|
}
|
|
|
|
// If the next token is an identifier and we have a legal program,
|
|
// it must be a typename. In that case this declaration introduces
|
|
// an alias type.
|
|
make_alias := P.tok == Scanner.IDENT;
|
|
|
|
// If we have an explicit forward declaration, TryType will not
|
|
// find a type and return nil.
|
|
typ := P.TryType();
|
|
|
|
if typ != nil {
|
|
if make_alias {
|
|
alias := Globals.NewType(Type.ALIAS);
|
|
alias.elt = typ;
|
|
typ = alias;
|
|
}
|
|
obj.typ = typ;
|
|
if typ.obj == nil {
|
|
typ.obj = obj; // primary type object
|
|
}
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseVarSpec(exported bool) {
|
|
P.Trace("VarSpec");
|
|
|
|
list := P.ParseIdentDeclList(Object.VAR);
|
|
if P.tok == Scanner.ASSIGN {
|
|
P.Next();
|
|
P.ParseExpressionList();
|
|
} else {
|
|
typ := P.ParseVarType();
|
|
for p := list.first; p != nil; p = p.next {
|
|
p.obj.typ = typ;
|
|
}
|
|
if P.tok == Scanner.ASSIGN {
|
|
P.Next();
|
|
P.ParseExpressionList();
|
|
}
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
// TODO With method variables, we wouldn't need this dispatch function.
|
|
func (P *Parser) ParseSpec(exported bool, keyword int) {
|
|
switch keyword {
|
|
case Scanner.IMPORT: P.ParseImportSpec();
|
|
case Scanner.CONST: P.ParseConstSpec(exported);
|
|
case Scanner.TYPE: P.ParseTypeSpec(exported);
|
|
case Scanner.VAR: P.ParseVarSpec(exported);
|
|
default: panic "UNREACHABLE";
|
|
}
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseDecl(exported bool, keyword int) {
|
|
P.Trace("Decl");
|
|
|
|
P.Expect(keyword);
|
|
if P.tok == Scanner.LPAREN {
|
|
P.Next();
|
|
for P.tok == Scanner.IDENT {
|
|
P.ParseSpec(exported, keyword);
|
|
if P.tok != Scanner.RPAREN {
|
|
// P.Expect(Scanner.SEMICOLON);
|
|
P.Optional(Scanner.SEMICOLON); // TODO this seems wrong! (needed for math.go)
|
|
}
|
|
}
|
|
P.Next();
|
|
} else {
|
|
P.ParseSpec(exported, keyword);
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseFuncDecl(exported bool) {
|
|
P.Trace("FuncDecl");
|
|
|
|
P.Expect(Scanner.FUNC);
|
|
ident, typ := P.ParseNamedSignature();
|
|
obj := P.DeclareFunc(ident, typ); // need obj later for statements
|
|
obj.exported = exported;
|
|
if P.tok == Scanner.SEMICOLON {
|
|
// forward declaration
|
|
P.Next();
|
|
} else {
|
|
P.ParseBlock(typ.scope);
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseExportDecl() {
|
|
P.Trace("ExportDecl");
|
|
|
|
// TODO this needs to be clarified - the current syntax is
|
|
// "everything goes" - sigh...
|
|
//P.Expect(Scanner.EXPORT);
|
|
has_paren := false;
|
|
if P.tok == Scanner.LPAREN {
|
|
P.Next();
|
|
has_paren = true;
|
|
}
|
|
for P.tok == Scanner.IDENT {
|
|
P.exports.AddStr(P.ParseIdent());
|
|
P.Optional(Scanner.COMMA); // TODO this seems wrong
|
|
}
|
|
if has_paren {
|
|
P.Expect(Scanner.RPAREN)
|
|
}
|
|
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseDeclaration() {
|
|
P.Trace("Declaration");
|
|
indent := P.indent;
|
|
|
|
exported := false;
|
|
if P.tok == Scanner.EXPORT {
|
|
if P.level == 0 {
|
|
exported = true;
|
|
} else {
|
|
P.Error(P.pos, "local declarations cannot be exported");
|
|
}
|
|
P.Next();
|
|
}
|
|
|
|
switch P.tok {
|
|
case Scanner.CONST, Scanner.TYPE, Scanner.VAR:
|
|
P.ParseDecl(exported, P.tok);
|
|
case Scanner.FUNC:
|
|
P.ParseFuncDecl(exported);
|
|
case Scanner.EXPORT:
|
|
if exported {
|
|
P.Error(P.pos, "cannot mark export declaration for export");
|
|
}
|
|
P.Next();
|
|
P.ParseExportDecl();
|
|
default:
|
|
if exported && (P.tok == Scanner.IDENT || P.tok == Scanner.LPAREN) {
|
|
P.ParseExportDecl();
|
|
} else {
|
|
P.Error(P.pos, "declaration expected");
|
|
P.Next(); // make progress
|
|
}
|
|
}
|
|
|
|
if indent != P.indent {
|
|
panic "imbalanced tracing code (Declaration)"
|
|
}
|
|
P.Ecart();
|
|
}
|
|
|
|
|
|
// ----------------------------------------------------------------------------
|
|
// Program
|
|
|
|
func (P *Parser) ResolveUndefTypes() {
|
|
if !P.semantic_checks {
|
|
return;
|
|
}
|
|
|
|
for p := P.undef_types.first; p != nil; p = p.next {
|
|
typ := p.typ;
|
|
if typ.form != Type.POINTER {
|
|
panic "unresolved types should be pointers only";
|
|
}
|
|
if typ.elt.form != Type.UNDEF {
|
|
panic "unresolved pointer should point to undefined type";
|
|
}
|
|
obj := typ.elt.obj;
|
|
typ.elt = obj.typ;
|
|
if typ.elt.form == Type.UNDEF {
|
|
P.Error(obj.pos, `"` + obj.ident + `" is not declared`);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
func (P *Parser) MarkExports() {
|
|
if !P.semantic_checks {
|
|
return;
|
|
}
|
|
|
|
scope := P.top_scope;
|
|
for p := P.exports.first; p != nil; p = p.next {
|
|
obj := scope.Lookup(p.str);
|
|
if obj != nil {
|
|
obj.exported = true;
|
|
// For now we export deep
|
|
// TODO this should change eventually - we need selective export
|
|
if obj.kind == Object.TYPE {
|
|
typ := obj.typ;
|
|
if typ.form == Type.STRUCT || typ.form == Type.INTERFACE {
|
|
scope := typ.scope;
|
|
for p := scope.entries.first; p != nil; p = p.next {
|
|
p.obj.exported = true;
|
|
}
|
|
}
|
|
}
|
|
} else {
|
|
// TODO need to report proper src position
|
|
P.Error(-1, `"` + p.str + `" is not declared - cannot be exported`);
|
|
}
|
|
}
|
|
}
|
|
|
|
|
|
func (P *Parser) ParseProgram() {
|
|
P.Trace("Program");
|
|
|
|
P.OpenScope();
|
|
P.Expect(Scanner.PACKAGE);
|
|
pkg := Globals.NewPackage(P.S.filename);
|
|
pkg.obj = P.ParseIdentDecl(Object.PACKAGE);
|
|
P.comp.Insert(pkg);
|
|
if P.comp.npkgs != 1 {
|
|
panic "should have exactly one package now";
|
|
}
|
|
P.Optional(Scanner.SEMICOLON);
|
|
|
|
{ if P.level != 0 {
|
|
panic "incorrect scope level";
|
|
}
|
|
P.OpenScope();
|
|
pkg.scope = P.top_scope;
|
|
for P.tok == Scanner.IMPORT {
|
|
P.ParseDecl(false, Scanner.IMPORT);
|
|
P.Optional(Scanner.SEMICOLON);
|
|
}
|
|
|
|
for P.tok != Scanner.EOF {
|
|
P.ParseDeclaration();
|
|
P.Optional(Scanner.SEMICOLON);
|
|
}
|
|
|
|
P.ResolveUndefTypes();
|
|
P.MarkExports();
|
|
P.CloseScope();
|
|
if P.level != 0 {
|
|
panic "incorrect scope level";
|
|
}
|
|
}
|
|
|
|
P.CloseScope();
|
|
P.Ecart();
|
|
}
|