Commit c048ee21 authored by Robert Griesemer's avatar Robert Griesemer

- converted expr representation of ast into a new representation

using interfaces properly => much cleaner code
- converted tracing code to use 'defer' statement
- next steps: convert rest of ast as well

R=r
OCL=24277
CL=24277
parent f9cc900a
......@@ -17,8 +17,7 @@ type (
Type struct;
Block struct;
Lit struct;
Expr struct;
Expr interface;
Stat struct;
Decl struct;
)
......@@ -128,26 +127,6 @@ type Node struct {
}
// ----------------------------------------------------------------------------
// Literals
type Lit struct {
Node;
// Identifiers
Obj *Object;
// Constant literals
// Type literals
Len *Expr; // array length
Dir int; // channel direction
Key *Type; // receiver or map key type
Elt *Type; // array, map, channel, pointer element, or function result type
List *array.Array; End int; // struct fields, interface methods, function parameters
}
// ----------------------------------------------------------------------------
// Scopes
......@@ -218,87 +197,6 @@ func (scope *Scope) Print() {
}
// ----------------------------------------------------------------------------
// Blocks
//
// Syntactic constructs of the form:
//
// "{" StatementList "}"
// ":" StatementList
type Block struct {
Node;
List *array.Array;
End int; // position of closing "}" if present
}
func NewBlock(pos, tok int) *Block {
assert(tok == Scanner.LBRACE || tok == Scanner.COLON);
b := new(Block);
b.Pos, b.Tok, b.List = pos, tok, array.New(0);
return b;
}
// ----------------------------------------------------------------------------
// Expressions
type Expr struct {
Node;
X, Y *Expr; // binary (X, Y) and unary (Y) expressions
Obj *Object; // identifiers, literals
Typ *Type;
}
// Length of a comma-separated expression list.
func (x *Expr) Len() int {
if x == nil {
return 0;
}
n := 1;
for ; x.Tok == Scanner.COMMA; x = x.Y {
n++;
}
return n;
}
// The i'th expression in a comma-separated expression list.
func (x *Expr) At(i int) *Expr {
for j := 0; j < i; j++ {
assert(x.Tok == Scanner.COMMA);
x = x.Y;
}
if x.Tok == Scanner.COMMA {
x = x.X;
}
return x;
}
func NewExpr(pos, tok int, x, y *Expr) *Expr {
if x != nil && x.Tok == Scanner.TYPE || y != nil && y.Tok == Scanner.TYPE {
panic("no type expression allowed");
}
e := new(Expr);
e.Pos, e.Tok, e.X, e.Y = pos, tok, x, y;
return e;
}
// TODO probably don't need the tok parameter eventually
func NewLit(tok int, obj *Object) *Expr {
e := new(Expr);
e.Pos, e.Tok, e.Obj, e.Typ = obj.Pos, tok, obj, obj.Typ;
return e;
}
var BadExpr = NewExpr(0, Scanner.ILLEGAL, nil, nil);
// ----------------------------------------------------------------------------
// Types
......@@ -388,7 +286,7 @@ type Type struct {
// syntactic components
Pos int; // source position (< 0 if unknown position)
Expr *Expr; // type name, array length
Expr Expr; // type name, array length
Mode int; // channel mode
Key *Type; // receiver type or map key
Elt *Type; // type name type, array, map, channel or pointer element type, function result type
......@@ -411,25 +309,6 @@ func NewType(pos, form int) *Type {
}
func (t *Type) Nfields() int {
if t.List == nil {
return 0;
}
nx, nt := 0, 0;
for i, n := 0, t.List.Len(); i < n; i++ {
if t.List.At(i).(*Expr).Tok == Scanner.TYPE {
nt++;
} else {
nx++;
}
}
if nx == 0 {
return nt;
}
return nx;
}
func (typ* Type) String() string {
if typ != nil {
return
......@@ -441,31 +320,199 @@ func (typ* Type) String() string {
}
// requires complete Type.Pos access
func NewTypeExpr(typ *Type) *Expr {
e := new(Expr);
e.Pos, e.Tok, e.Typ = typ.Pos, Scanner.TYPE, typ;
return e;
var BadType = NewType(0, Scanner.ILLEGAL);
// ----------------------------------------------------------------------------
// Blocks
//
// Syntactic constructs of the form:
//
// "{" StatementList "}"
// ":" StatementList
type Block struct {
Node;
List *array.Array;
End int; // position of closing "}" if present
}
// requires complete Type.String access
func (x *Expr) String() string {
if x != nil {
return
"Expr(" +
Scanner.TokenString(x.Tok) + ", " +
x.X.String() + ", " +
x.Y.String() + ", " +
x.Obj.String() + ", " +
x.Typ.String() +
")";
func NewBlock(pos, tok int) *Block {
assert(tok == Scanner.LBRACE || tok == Scanner.COLON);
b := new(Block);
b.Pos, b.Tok, b.List = pos, tok, array.New(0);
return b;
}
// ----------------------------------------------------------------------------
// Expressions
type (
Visitor interface;
Expr interface {
Pos() int;
Visit(v Visitor);
};
BadExpr struct {
Pos_ int;
};
Ident struct {
Pos_ int;
Obj *Object;
};
BinaryExpr struct {
Pos_, Tok int;
X, Y Expr;
};
UnaryExpr struct {
Pos_, Tok int;
X Expr;
};
BasicLit struct {
Pos_, Tok int;
Val string
};
FunctionLit struct {
Pos_ int; // position of "func"
Typ *Type;
Body *Block;
};
CompositeLit struct {
Pos_ int; // position of "{"
Typ *Type;
Elts Expr;
};
TypeLit struct {
Typ *Type;
};
Selector struct {
Pos_ int; // position of "."
X Expr;
Sel *Ident;
};
TypeGuard struct {
Pos_ int; // position of "."
X Expr;
Typ *Type;
};
Index struct {
Pos_ int; // position of "["
X, I Expr;
};
Call struct {
Pos_ int; // position of "("
F, Args Expr
};
)
type Visitor interface {
DoBadExpr(x *BadExpr);
DoIdent(x *Ident);
DoBinaryExpr(x *BinaryExpr);
DoUnaryExpr(x *UnaryExpr);
DoBasicLit(x *BasicLit);
DoFunctionLit(x *FunctionLit);
DoCompositeLit(x *CompositeLit);
DoTypeLit(x *TypeLit);
DoSelector(x *Selector);
DoTypeGuard(x *TypeGuard);
DoIndex(x *Index);
DoCall(x *Call);
}
func (x *BadExpr) Pos() int { return x.Pos_; }
func (x *Ident) Pos() int { return x.Pos_; }
func (x *BinaryExpr) Pos() int { return x.Pos_; }
func (x *UnaryExpr) Pos() int { return x.Pos_; }
func (x *BasicLit) Pos() int { return x.Pos_; }
func (x *FunctionLit) Pos() int { return x.Pos_; }
func (x *CompositeLit) Pos() int { return x.Pos_; }
func (x *TypeLit) Pos() int { return x.Typ.Pos; }
func (x *Selector) Pos() int { return x.Pos_; }
func (x *TypeGuard) Pos() int { return x.Pos_; }
func (x *Index) Pos() int { return x.Pos_; }
func (x *Call) Pos() int { return x.Pos_; }
func (x *BadExpr) Visit(v Visitor) { v.DoBadExpr(x); }
func (x *Ident) Visit(v Visitor) { v.DoIdent(x); }
func (x *BinaryExpr) Visit(v Visitor) { v.DoBinaryExpr(x); }
func (x *UnaryExpr) Visit(v Visitor) { v.DoUnaryExpr(x); }
func (x *BasicLit) Visit(v Visitor) { v.DoBasicLit(x); }
func (x *FunctionLit) Visit(v Visitor) { v.DoFunctionLit(x); }
func (x *CompositeLit) Visit(v Visitor) { v.DoCompositeLit(x); }
func (x *TypeLit) Visit(v Visitor) { v.DoTypeLit(x); }
func (x *Selector) Visit(v Visitor) { v.DoSelector(x); }
func (x *TypeGuard) Visit(v Visitor) { v.DoTypeGuard(x); }
func (x *Index) Visit(v Visitor) { v.DoIndex(x); }
func (x *Call) Visit(v Visitor) { v.DoCall(x); }
// Length of a comma-separated expression list.
func ExprLen(x Expr) int {
if x == nil {
return 0;
}
return "nil";
n := 1;
for {
if p, ok := x.(*BinaryExpr); ok && p.Tok == Scanner.COMMA {
n++;
x = p.Y;
} else {
break;
}
}
return n;
}
var BadType = NewType(0, Scanner.ILLEGAL);
func ExprAt(x Expr, i int) Expr {
for j := 0; j < i; j++ {
assert(x.(*BinaryExpr).Tok == Scanner.COMMA);
x = x.(*BinaryExpr).Y;
}
if t, is_binary := x.(*BinaryExpr); is_binary && t.Tok == Scanner.COMMA {
x = t.X;
}
return x;
}
func (t *Type) Nfields() int {
if t.List == nil {
return 0;
}
nx, nt := 0, 0;
for i, n := 0, t.List.Len(); i < n; i++ {
if dummy, ok := t.List.At(i).(*TypeLit); ok {
nt++;
} else {
nx++;
}
}
if nx == 0 {
return nt;
}
return nx;
}
// ----------------------------------------------------------------------------
......@@ -474,7 +521,7 @@ var BadType = NewType(0, Scanner.ILLEGAL);
type Stat struct {
Node;
Init, Post *Stat;
Expr *Expr;
Expr Expr;
Body *Block; // composite statement body
Decl *Decl; // declaration statement
}
......@@ -495,9 +542,10 @@ var BadStat = NewStat(0, Scanner.ILLEGAL);
type Decl struct {
Node;
Ident *Expr; // nil for ()-style declarations
Ident Expr; // nil for ()-style declarations
Typ *Type;
Val *Expr;
Val Expr;
Body *Block;
// list of *Decl for ()-style declarations
List *array.Array; End int;
}
......@@ -531,7 +579,7 @@ func NewComment(pos int, text string) *Comment {
type Program struct {
Pos int; // tok is Scanner.PACKAGE
Ident *Expr;
Ident Expr;
Decls *array.Array;
Comments *array.Array;
}
......
......@@ -158,6 +158,8 @@ func fileExists(name string) bool {
func addDeps(globalset map [string] bool, wset *array.Array, src_file string, flags *Flags) {
panic();
/*
dummy, found := globalset[src_file];
if !found {
globalset[src_file] = true;
......@@ -198,6 +200,7 @@ func addDeps(globalset map [string] bool, wset *array.Array, src_file string, fl
print("\n\n");
}
}
*/
}
......
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