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go/usr/austin/eval/compiler.go
Austin Clements da4a22993e Fix declared and not used errors and unused import errors in
the interpreter and update code to use ast.BasicDecl and
multi-type switch.  There are still a lot of "switch _ :=
x.(type)" that should make use of the new type switch syntax,
but those will be a different CL.

R=rsc
APPROVED=rsc
DELTA=58  (16 added, 23 deleted, 19 changed)
OCL=34853
CL=34963
2009-09-24 08:25:14 -07:00

98 lines
2.4 KiB
Go

// Copyright 2009 The Go Authors. All rights reserved.
// Use of this source code is governed by a BSD-style
// license that can be found in the LICENSE file.
package eval
import (
"fmt";
"go/scanner";
"go/token";
)
type positioned interface {
Pos() token.Position;
}
// A compiler captures information used throughout an entire
// compilation. Currently it includes only the error handler.
//
// TODO(austin) This might actually represent package level, in which
// case it should be package compiler.
type compiler struct {
errors scanner.ErrorHandler;
numErrors int;
silentErrors int;
}
func (a *compiler) diagAt(pos positioned, format string, args ...) {
a.errors.Error(pos.Pos(), fmt.Sprintf(format, args));
a.numErrors++;
}
func (a *compiler) numError() int {
return a.numErrors + a.silentErrors;
}
// The universal scope
func newUniverse() *Scope {
sc := &Scope{nil, 0};
sc.block = &block{
offset: 0,
scope: sc,
global: true,
defs: make(map[string] Def)
};
return sc;
}
var universe *Scope = newUniverse();
// TODO(austin) These can all go in stmt.go now
type label struct {
name string;
desc string;
// The PC goto statements should jump to, or nil if this label
// cannot be goto'd (such as an anonymous for loop label).
gotoPC *uint;
// The PC break statements should jump to, or nil if a break
// statement is invalid.
breakPC *uint;
// The PC continue statements should jump to, or nil if a
// continue statement is invalid.
continuePC *uint;
// The position where this label was resolved. If it has not
// been resolved yet, an invalid position.
resolved token.Position;
// The position where this label was first jumped to.
used token.Position;
}
// A funcCompiler captures information used throughout the compilation
// of a single function body.
type funcCompiler struct {
*compiler;
fnType *FuncType;
// Whether the out variables are named. This affects what
// kinds of return statements are legal.
outVarsNamed bool;
*codeBuf;
flow *flowBuf;
labels map[string] *label;
}
// A blockCompiler captures information used throughout the compilation
// of a single block within a function.
type blockCompiler struct {
*funcCompiler;
block *block;
// The label of this block, used for finding break and
// continue labels.
label *label;
// The blockCompiler for the block enclosing this one, or nil
// for a function-level block.
parent *blockCompiler;
}