| // Copyright (C) 2014 The Android Open Source Project |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| package parser |
| |
| import ( |
| "android.googlesource.com/platform/tools/gpu/api/ast" |
| "android.googlesource.com/platform/tools/gpu/parse" |
| ) |
| |
| // lhs { extend } |
| func requireExpression(p *parse.Parser, cst *parse.Branch) ast.Node { |
| lhs := requireLHSExpression(p, cst) |
| for { |
| if e := extendExpression(p, cst, lhs); e != nil { |
| lhs = e |
| } else { |
| break |
| } |
| } |
| return lhs |
| } |
| |
| // ( group | switch | literal | unary_op | generic) |
| func requireLHSExpression(p *parse.Parser, cst *parse.Branch) ast.Node { |
| if g := group(p, cst); g != nil { |
| return g |
| } |
| if s := switch_(p, cst); s != nil { |
| return s |
| } |
| if l := literal(p, cst); l != nil { |
| return l |
| } |
| if u := unaryOp(p, cst); u != nil { |
| return u |
| } |
| if g := generic(p, cst); g != nil { |
| return g |
| } |
| p.Expected("expression") |
| return &ast.Invalid{} |
| } |
| |
| // lhs (index | call | binary_op | member) |
| func extendExpression(p *parse.Parser, cst *parse.Branch, lhs ast.Node) ast.Node { |
| if i := index(p, cst, lhs); i != nil { |
| return i |
| } |
| if c := call(p, cst, lhs); c != nil { |
| return c |
| } |
| if e := binaryOp(p, cst, lhs); e != nil { |
| return e |
| } |
| if m := member(p, cst, lhs); m != nil { |
| return m |
| } |
| return nil |
| } |
| |
| // 'null' | 'true' | 'false' | '"' string '"' | '?' | number |
| func literal(p *parse.Parser, cst *parse.Branch) ast.Node { |
| if l := keyword(ast.KeywordNull, p, cst); l != nil { |
| return &ast.Null{CST: l} |
| } |
| if l := keyword(ast.KeywordTrue, p, cst); l != nil { |
| return &ast.Bool{CST: l, Value: true} |
| } |
| if l := keyword(ast.KeywordFalse, p, cst); l != nil { |
| return &ast.Bool{CST: l, Value: false} |
| } |
| if s := string_(p, cst); s != nil { |
| return s |
| } |
| if peekOperator(ast.OpUnknown, p) { |
| n := &ast.Unknown{} |
| p.ParseLeaf(cst, func(p *parse.Parser, l *parse.Leaf) { |
| n.CST = l |
| requireOperator(ast.OpUnknown, p, cst) |
| }) |
| return n |
| } |
| if n := number(p, cst); n != nil { |
| return n |
| } |
| return nil |
| } |
| |
| // '"' string '"' |
| func string_(p *parse.Parser, cst *parse.Branch) *ast.String { |
| if !p.Rune(ast.Quote) { |
| return nil |
| } |
| n := &ast.String{} |
| p.ParseLeaf(cst, func(p *parse.Parser, l *parse.Leaf) { |
| n.CST = l |
| p.SeekRune(ast.Quote) |
| p.Rune(ast.Quote) |
| l.SetToken(p.Consume()) |
| v := l.Token().String() |
| n.Value = v[1 : len(v)-1] |
| }) |
| return n |
| } |
| |
| func requireString(p *parse.Parser, cst *parse.Branch) *ast.String { |
| s := string_(p, cst) |
| if s == nil { |
| p.Expected("string") |
| } |
| return s |
| } |
| |
| // standard numeric formats |
| func number(p *parse.Parser, cst *parse.Branch) *ast.Number { |
| _ = p.Rune('+') || p.Rune('-') // optional sign |
| if p.Numeric() == parse.NotNumeric { |
| p.Rollback() |
| return nil |
| } |
| n := &ast.Number{} |
| p.ParseLeaf(cst, func(p *parse.Parser, l *parse.Leaf) { n.CST = l }) |
| n.Value = n.CST.Token().String() |
| return n |
| } |
| |
| func requireNumber(p *parse.Parser, cst *parse.Branch) *ast.Number { |
| n := number(p, cst) |
| if n == nil { |
| p.Expected("number") |
| } |
| return n |
| } |
| |
| // '(' expression ')' |
| func group(p *parse.Parser, cst *parse.Branch) *ast.Group { |
| if !peekOperator(ast.OpListStart, p) { |
| return nil |
| } |
| e := &ast.Group{} |
| p.ParseBranch(cst, func(p *parse.Parser, cst *parse.Branch) { |
| e.CST = cst |
| requireOperator(ast.OpListStart, p, cst) |
| e.Expression = requireExpression(p, cst) |
| requireOperator(ast.OpListEnd, p, cst) |
| }) |
| return e |
| } |
| |
| // switch '{' { 'case' { expresion } ':' block } '}' |
| func switch_(p *parse.Parser, cst *parse.Branch) *ast.Switch { |
| if !peekKeyword(ast.KeywordSwitch, p) { |
| return nil |
| } |
| e := &ast.Switch{} |
| p.ParseBranch(cst, func(p *parse.Parser, cst *parse.Branch) { |
| e.CST = cst |
| requireKeyword(ast.KeywordSwitch, p, cst) |
| e.Value = requireExpression(p, cst) |
| requireOperator(ast.OpBlockStart, p, cst) |
| for !operator(ast.OpBlockEnd, p, cst) { |
| p.ParseBranch(cst, func(p *parse.Parser, cst *parse.Branch) { |
| entry := &ast.Case{} |
| entry.CST = cst |
| requireKeyword(ast.KeywordCase, p, cst) |
| for !operator(ast.OpExtends, p, cst) { |
| if len(entry.Conditions) > 0 { |
| requireOperator(ast.OpListSeparator, p, cst) |
| } |
| entry.Conditions = append(entry.Conditions, requireExpression(p, cst)) |
| } |
| entry.Block = requireBlock(p, cst) |
| e.Cases = append(e.Cases, entry) |
| }) |
| } |
| }) |
| return e |
| } |
| |
| // lhs '[' expression [ ':' [ expression ] ] ']' |
| func index(p *parse.Parser, cst *parse.Branch, lhs ast.Node) *ast.Index { |
| if !peekOperator(ast.OpIndexStart, p) { |
| return nil |
| } |
| e := &ast.Index{Object: lhs} |
| p.ParseBranch(cst, func(p *parse.Parser, cst *parse.Branch) { |
| e.CST = cst |
| requireOperator(ast.OpIndexStart, p, cst) |
| e.Index = requireExpression(p, cst) |
| if operator(ast.OpSlice, p, cst) { |
| n := &ast.BinaryOp{LHS: e.Index, Operator: ast.OpSlice} |
| if !peekOperator(ast.OpIndexEnd, p) { |
| p.ParseBranch(cst, func(p *parse.Parser, cst *parse.Branch) { |
| n.CST = cst |
| n.RHS = requireExpression(p, cst) |
| }) |
| } |
| e.Index = n |
| } |
| requireOperator(ast.OpIndexEnd, p, cst) |
| }) |
| return e |
| } |
| |
| // lhs '(' [ expression { ',' expression } ] ')' |
| func call(p *parse.Parser, cst *parse.Branch, lhs ast.Node) *ast.Call { |
| if !peekOperator(ast.OpListStart, p) { |
| return nil |
| } |
| e := &ast.Call{Target: lhs} |
| p.ParseBranch(cst, func(p *parse.Parser, cst *parse.Branch) { |
| e.CST = cst |
| requireOperator(ast.OpListStart, p, cst) |
| for !operator(ast.OpListEnd, p, cst) { |
| arg := requireExpression(p, cst) |
| if i, ok := arg.(*ast.Generic); ok && operator(ast.OpInitialise, p, cst) { |
| n := &ast.NamedArg{Name: i.Name} |
| p.ParseBranch(cst, func(p *parse.Parser, cst *parse.Branch) { |
| n.CST = cst |
| n.Value = requireExpression(p, cst) |
| }) |
| arg = n |
| } |
| e.Arguments = append(e.Arguments, arg) |
| if operator(ast.OpListEnd, p, cst) { |
| break |
| } |
| requireOperator(ast.OpListSeparator, p, cst) |
| } |
| }) |
| return e |
| } |
| |
| // lhs '.' identifier |
| func member(p *parse.Parser, cst *parse.Branch, lhs ast.Node) *ast.Member { |
| if !peekOperator(ast.OpMember, p) { |
| return nil |
| } |
| e := &ast.Member{Object: lhs} |
| p.ParseBranch(cst, func(p *parse.Parser, cst *parse.Branch) { |
| e.CST = cst |
| requireOperator(ast.OpMember, p, cst) |
| e.Name = requireIdentifier(p, cst) |
| }) |
| return e |
| } |