mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-11-14 15:07:26 +01:00
701 lines
18 KiB
Go
701 lines
18 KiB
Go
// Copyright 2020 The Ebiten Authors
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//
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// Licensed under the Apache License, Version 2.0 (the "License");
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// you may not use this file except in compliance with the License.
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// You may obtain a copy of the License at
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//
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// http://www.apache.org/licenses/LICENSE-2.0
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//
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// Unless required by applicable law or agreed to in writing, software
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// distributed under the License is distributed on an "AS IS" BASIS,
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// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
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// See the License for the specific language governing permissions and
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// limitations under the License.
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package shader
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import (
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"fmt"
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"go/ast"
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gconstant "go/constant"
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"go/token"
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"strings"
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"github.com/hajimehoshi/ebiten/v2/internal/shaderir"
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)
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func (cs *compileState) forceToInt(node ast.Node, expr *shaderir.Expr) bool {
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if !canTruncateToInteger(expr.Const) {
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cs.addError(node.Pos(), fmt.Sprintf("constant %s truncated to integer", expr.Const.String()))
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return false
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}
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expr.ConstType = shaderir.ConstTypeInt
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return true
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}
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func (cs *compileState) parseStmt(block *block, fname string, stmt ast.Stmt, inParams, outParams []variable) ([]shaderir.Stmt, bool) {
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var stmts []shaderir.Stmt
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switch stmt := stmt.(type) {
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case *ast.AssignStmt:
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switch stmt.Tok {
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case token.DEFINE:
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if len(stmt.Lhs) != len(stmt.Rhs) && len(stmt.Rhs) != 1 {
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cs.addError(stmt.Pos(), fmt.Sprintf("single-value context and multiple-value context cannot be mixed"))
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return nil, false
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}
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ss, ok := cs.assign(block, fname, stmt.Pos(), stmt.Lhs, stmt.Rhs, inParams, true)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, ss...)
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case token.ASSIGN:
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if len(stmt.Lhs) != len(stmt.Rhs) && len(stmt.Rhs) != 1 {
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cs.addError(stmt.Pos(), fmt.Sprintf("single-value context and multiple-value context cannot be mixed"))
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return nil, false
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}
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ss, ok := cs.assign(block, fname, stmt.Pos(), stmt.Lhs, stmt.Rhs, inParams, false)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, ss...)
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case token.ADD_ASSIGN, token.SUB_ASSIGN, token.MUL_ASSIGN, token.QUO_ASSIGN, token.REM_ASSIGN:
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var op shaderir.Op
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switch stmt.Tok {
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case token.ADD_ASSIGN:
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op = shaderir.Add
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case token.SUB_ASSIGN:
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op = shaderir.Sub
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case token.MUL_ASSIGN:
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op = shaderir.Mul
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case token.QUO_ASSIGN:
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op = shaderir.Div
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case token.REM_ASSIGN:
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op = shaderir.ModOp
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}
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rhs, _, ss, ok := cs.parseExpr(block, stmt.Rhs[0], true)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, ss...)
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lhs, ts, ss, ok := cs.parseExpr(block, stmt.Lhs[0], true)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, ss...)
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if rhs[0].Type == shaderir.NumberExpr && ts[0].Main == shaderir.Int {
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if !cs.forceToInt(stmt, &rhs[0]) {
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return nil, false
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}
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}
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.Assign,
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Exprs: []shaderir.Expr{
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lhs[0],
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{
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Type: shaderir.Binary,
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Op: op,
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Exprs: []shaderir.Expr{
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lhs[0],
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rhs[0],
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},
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},
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},
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})
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default:
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cs.addError(stmt.Pos(), fmt.Sprintf("unexpected token: %s", stmt.Tok))
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}
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case *ast.BlockStmt:
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b, ok := cs.parseBlock(block, fname, stmt.List, inParams, outParams, true)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.BlockStmt,
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Blocks: []*shaderir.Block{
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b.ir,
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},
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})
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case *ast.DeclStmt:
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ss, ok := cs.parseDecl(block, stmt.Decl)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, ss...)
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case *ast.ForStmt:
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msg := "for-statement must follow this format: for (varname) := (constant); (varname) (op) (constant); (varname) (op) (constant) { ..."
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if stmt.Init == nil {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if stmt.Cond == nil {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if stmt.Post == nil {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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// Create a new pseudo block for the initial statement, so that the counter variable belongs to the
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// new pseudo block for each for-loop. Without this, the samely named counter variables in different
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// for-loops confuses the parser.
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pseudoBlock, ok := cs.parseBlock(block, fname, []ast.Stmt{stmt.Init}, inParams, outParams, false)
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if !ok {
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return nil, false
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}
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ss := pseudoBlock.ir.Stmts
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if len(ss) != 1 {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if ss[0].Type != shaderir.Assign {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if ss[0].Exprs[0].Type != shaderir.LocalVariable {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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varidx := ss[0].Exprs[0].Index
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if ss[0].Exprs[1].Type != shaderir.NumberExpr {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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vartype := pseudoBlock.vars[0].typ
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init := ss[0].Exprs[1].Const
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exprs, ts, ss, ok := cs.parseExpr(pseudoBlock, stmt.Cond, true)
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if !ok {
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return nil, false
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}
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if len(exprs) != 1 {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if len(ts) != 1 || ts[0].Main != shaderir.Bool {
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cs.addError(stmt.Pos(), "for-statement's condition must be bool")
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return nil, false
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}
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if len(ss) != 0 {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if exprs[0].Type != shaderir.Binary {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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op := exprs[0].Op
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if op != shaderir.LessThanOp && op != shaderir.LessThanEqualOp && op != shaderir.GreaterThanOp && op != shaderir.GreaterThanEqualOp && op != shaderir.EqualOp && op != shaderir.NotEqualOp {
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cs.addError(stmt.Pos(), "for-statement's condition must have one of these operators: <, <=, >, >=, ==, !=")
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return nil, false
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}
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if exprs[0].Exprs[0].Type != shaderir.LocalVariable {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if exprs[0].Exprs[0].Index != varidx {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if exprs[0].Exprs[1].Type != shaderir.NumberExpr {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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end := exprs[0].Exprs[1].Const
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postSs, ok := cs.parseStmt(pseudoBlock, fname, stmt.Post, inParams, outParams)
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if !ok {
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return nil, false
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}
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if len(postSs) != 1 {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if postSs[0].Type != shaderir.Assign {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if postSs[0].Exprs[0].Type != shaderir.LocalVariable {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if postSs[0].Exprs[0].Index != varidx {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if postSs[0].Exprs[1].Type != shaderir.Binary {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if postSs[0].Exprs[1].Exprs[0].Type != shaderir.LocalVariable {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if postSs[0].Exprs[1].Exprs[0].Index != varidx {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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if postSs[0].Exprs[1].Exprs[1].Type != shaderir.NumberExpr {
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cs.addError(stmt.Pos(), msg)
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return nil, false
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}
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delta := postSs[0].Exprs[1].Exprs[1].Const
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switch postSs[0].Exprs[1].Op {
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case shaderir.Add:
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case shaderir.Sub:
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delta = gconstant.UnaryOp(token.SUB, delta, 0)
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default:
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cs.addError(stmt.Pos(), "for-statement's post statement must have one of these operators: +=, -=, ++, --")
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return nil, false
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}
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b, ok := cs.parseBlock(pseudoBlock, fname, []ast.Stmt{stmt.Body}, inParams, outParams, true)
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if !ok {
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return nil, false
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}
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bodyir := b.ir
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for len(bodyir.Stmts) == 1 && bodyir.Stmts[0].Type == shaderir.BlockStmt {
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bodyir = bodyir.Stmts[0].Blocks[0]
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}
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// As the pseudo block is not actually used, copy the variable part to the actual block.
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// This must be done after parsing the for-loop is done, or the duplicated variables confuses the
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// parsing.
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v := pseudoBlock.vars[0]
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v.forLoopCounter = true
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block.vars = append(block.vars, v)
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.For,
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Blocks: []*shaderir.Block{bodyir},
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ForVarType: vartype,
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ForVarIndex: varidx,
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ForInit: init,
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ForEnd: end,
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ForOp: op,
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ForDelta: delta,
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})
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case *ast.IfStmt:
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if stmt.Init != nil {
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init := stmt.Init
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stmt.Init = nil
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b, ok := cs.parseBlock(block, fname, []ast.Stmt{init, stmt}, inParams, outParams, true)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.BlockStmt,
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Blocks: []*shaderir.Block{b.ir},
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})
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return stmts, true
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}
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exprs, ts, ss, ok := cs.parseExpr(block, stmt.Cond, true)
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if !ok {
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return nil, false
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}
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if len(ts) != 1 || ts[0].Main != shaderir.Bool {
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var tss []string
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for _, t := range ts {
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tss = append(tss, t.String())
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}
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cs.addError(stmt.Pos(), fmt.Sprintf("if-condition must be bool but: %s", strings.Join(tss, ", ")))
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return nil, false
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}
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stmts = append(stmts, ss...)
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var bs []*shaderir.Block
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b, ok := cs.parseBlock(block, fname, stmt.Body.List, inParams, outParams, true)
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if !ok {
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return nil, false
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}
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bs = append(bs, b.ir)
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if stmt.Else != nil {
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switch s := stmt.Else.(type) {
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case *ast.BlockStmt:
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b, ok := cs.parseBlock(block, fname, s.List, inParams, outParams, true)
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if !ok {
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return nil, false
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}
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bs = append(bs, b.ir)
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default:
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b, ok := cs.parseBlock(block, fname, []ast.Stmt{s}, inParams, outParams, true)
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if !ok {
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return nil, false
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}
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bs = append(bs, b.ir)
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}
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}
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.If,
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Exprs: exprs,
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Blocks: bs,
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})
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case *ast.IncDecStmt:
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exprs, _, ss, ok := cs.parseExpr(block, stmt.X, true)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, ss...)
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var op shaderir.Op
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switch stmt.Tok {
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case token.INC:
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op = shaderir.Add
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case token.DEC:
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op = shaderir.Sub
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}
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.Assign,
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Exprs: []shaderir.Expr{
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exprs[0],
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{
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Type: shaderir.Binary,
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Op: op,
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Exprs: []shaderir.Expr{
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exprs[0],
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{
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Type: shaderir.NumberExpr,
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Const: gconstant.MakeInt64(1),
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ConstType: shaderir.ConstTypeInt,
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},
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},
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},
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},
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})
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case *ast.ReturnStmt:
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if len(stmt.Results) != len(outParams) && len(stmt.Results) != 1 {
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if !(len(stmt.Results) == 0 && len(outParams) > 0 && outParams[0].name != "") {
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// TODO: Check variable shadowings.
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// https://golang.org/ref/spec#Return_statements
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cs.addError(stmt.Pos(), fmt.Sprintf("the number of returning variables must be %d but %d", len(outParams), len(stmt.Results)))
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return nil, false
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}
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}
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for i, r := range stmt.Results {
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exprs, ts, ss, ok := cs.parseExpr(block, r, true)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, ss...)
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if len(exprs) > 1 {
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if len(stmt.Results) > 1 || len(outParams) == 1 {
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cs.addError(r.Pos(), "single-value context and multiple-value context cannot be mixed")
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return nil, false
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}
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}
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if len(outParams) > 1 && len(stmt.Results) == 1 {
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if len(exprs) == 1 {
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cs.addError(stmt.Pos(), fmt.Sprintf("the number of returning variables must be %d but %d", len(outParams), len(stmt.Results)))
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return nil, false
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}
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if len(exprs) > 1 && len(exprs) != len(outParams) {
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cs.addError(stmt.Pos(), fmt.Sprintf("the number of returning variables must be %d but %d", len(outParams), len(exprs)))
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return nil, false
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}
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}
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for j, t := range ts {
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expr := exprs[j]
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if expr.Type == shaderir.NumberExpr {
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switch outParams[i+j].typ.Main {
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case shaderir.Int:
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if !cs.forceToInt(stmt, &expr) {
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return nil, false
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}
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t = shaderir.Type{Main: shaderir.Int}
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case shaderir.Float:
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t = shaderir.Type{Main: shaderir.Float}
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}
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}
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if !t.Equal(&outParams[i+j].typ) {
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cs.addError(stmt.Pos(), fmt.Sprintf("cannot use type %s as type %s in return argument", t.String(), &outParams[i].typ))
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return nil, false
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}
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.Assign,
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Exprs: []shaderir.Expr{
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{
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Type: shaderir.LocalVariable,
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Index: len(inParams) + i + j,
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},
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expr,
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},
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})
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}
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}
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.Return,
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})
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case *ast.BranchStmt:
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switch stmt.Tok {
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case token.BREAK:
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.Break,
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})
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case token.CONTINUE:
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.Continue,
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})
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default:
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cs.addError(stmt.Pos(), fmt.Sprintf("invalid token: %s", stmt.Tok))
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return nil, false
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}
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case *ast.ExprStmt:
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if _, ok := stmt.X.(*ast.CallExpr); !ok {
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cs.addError(stmt.Pos(), fmt.Sprintf("the statement is evaluated but not used"))
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return nil, false
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}
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exprs, _, ss, ok := cs.parseExpr(block, stmt.X, true)
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if !ok {
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return nil, false
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}
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stmts = append(stmts, ss...)
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for _, expr := range exprs {
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// There can be a non-call expr like LocalVariable expressions.
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// These are necessary to be used as arguments for an outside function callers.
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if expr.Type != shaderir.Call {
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continue
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}
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if expr.Exprs[0].Type == shaderir.BuiltinFuncExpr {
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cs.addError(stmt.Pos(), fmt.Sprintf("the statement is evaluated but not used"))
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return nil, false
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}
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stmts = append(stmts, shaderir.Stmt{
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Type: shaderir.ExprStmt,
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Exprs: []shaderir.Expr{expr},
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})
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}
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default:
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cs.addError(stmt.Pos(), fmt.Sprintf("unexpected statement: %#v", stmt))
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return nil, false
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}
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return stmts, true
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}
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|
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func (cs *compileState) assign(block *block, fname string, pos token.Pos, lhs, rhs []ast.Expr, inParams []variable, define bool) ([]shaderir.Stmt, bool) {
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var stmts []shaderir.Stmt
|
|
var rhsExprs []shaderir.Expr
|
|
var rhsTypes []shaderir.Type
|
|
allblank := true
|
|
|
|
for i, e := range lhs {
|
|
if len(lhs) == len(rhs) {
|
|
// Prase RHS first for the order of the statements.
|
|
r, origts, ss, ok := cs.parseExpr(block, rhs[i], true)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
|
|
if define {
|
|
name := e.(*ast.Ident).Name
|
|
if name != "_" {
|
|
for _, v := range block.vars {
|
|
if v.name == name {
|
|
cs.addError(pos, fmt.Sprintf("duplicated local variable name: %s", name))
|
|
return nil, false
|
|
}
|
|
}
|
|
}
|
|
ts, ok := cs.functionReturnTypes(block, rhs[i])
|
|
if !ok {
|
|
ts = origts
|
|
}
|
|
if len(ts) > 1 {
|
|
cs.addError(pos, fmt.Sprintf("single-value context and multiple-value context cannot be mixed"))
|
|
return nil, false
|
|
}
|
|
|
|
t := ts[0]
|
|
if t.Main == shaderir.None {
|
|
t = toDefaultType(r[0].Const)
|
|
}
|
|
block.addNamedLocalVariable(name, t, e.Pos())
|
|
}
|
|
|
|
if len(r) > 1 {
|
|
cs.addError(pos, fmt.Sprintf("single-value context and multiple-value context cannot be mixed"))
|
|
return nil, false
|
|
}
|
|
|
|
l, _, ss, ok := cs.parseExpr(block, lhs[i], false)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
|
|
if l[0].Type == shaderir.Blank {
|
|
continue
|
|
}
|
|
|
|
var isAssignmentForbidden func(e *shaderir.Expr) bool
|
|
isAssignmentForbidden = func(e *shaderir.Expr) bool {
|
|
switch e.Type {
|
|
case shaderir.UniformVariable:
|
|
return true
|
|
case shaderir.LocalVariable:
|
|
if fname == cs.vertexEntry || fname == cs.fragmentEntry {
|
|
return e.Index < len(inParams)
|
|
}
|
|
case shaderir.FieldSelector:
|
|
return isAssignmentForbidden(&e.Exprs[0])
|
|
case shaderir.Index:
|
|
return isAssignmentForbidden(&e.Exprs[0])
|
|
}
|
|
return false
|
|
}
|
|
|
|
if isAssignmentForbidden(&l[0]) {
|
|
cs.addError(pos, fmt.Sprintf("a uniform variable cannot be assigned"))
|
|
return nil, false
|
|
}
|
|
allblank = false
|
|
|
|
if r[0].Type == shaderir.NumberExpr {
|
|
t, ok := block.findLocalVariableByIndex(l[0].Index)
|
|
if !ok {
|
|
cs.addError(pos, fmt.Sprintf("unexpected local variable index: %d", l[0].Index))
|
|
return nil, false
|
|
}
|
|
switch t.Main {
|
|
case shaderir.Int:
|
|
r[0].ConstType = shaderir.ConstTypeInt
|
|
case shaderir.Float:
|
|
r[0].ConstType = shaderir.ConstTypeFloat
|
|
}
|
|
}
|
|
|
|
if len(lhs) == 1 {
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Assign,
|
|
Exprs: []shaderir.Expr{l[0], r[0]},
|
|
})
|
|
} else {
|
|
// For variable swapping, use temporary variables.
|
|
t := origts[0]
|
|
if t.Main == shaderir.None {
|
|
t = toDefaultType(r[0].Const)
|
|
}
|
|
block.vars = append(block.vars, variable{
|
|
typ: t,
|
|
})
|
|
idx := len(block.vars) - 1
|
|
stmts = append(stmts,
|
|
shaderir.Stmt{
|
|
Type: shaderir.Assign,
|
|
Exprs: []shaderir.Expr{
|
|
{
|
|
Type: shaderir.LocalVariable,
|
|
Index: idx,
|
|
},
|
|
r[0],
|
|
},
|
|
},
|
|
shaderir.Stmt{
|
|
Type: shaderir.Assign,
|
|
Exprs: []shaderir.Expr{
|
|
l[0],
|
|
{
|
|
Type: shaderir.LocalVariable,
|
|
Index: idx,
|
|
},
|
|
},
|
|
})
|
|
}
|
|
} else {
|
|
if i == 0 {
|
|
var ss []shaderir.Stmt
|
|
var ok bool
|
|
rhsExprs, rhsTypes, ss, ok = cs.parseExpr(block, rhs[0], true)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
if len(rhsExprs) != len(lhs) {
|
|
cs.addError(pos, fmt.Sprintf("single-value context and multiple-value context cannot be mixed"))
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
}
|
|
|
|
if define {
|
|
name := e.(*ast.Ident).Name
|
|
if name != "_" {
|
|
for _, v := range block.vars {
|
|
if v.name == name {
|
|
cs.addError(pos, fmt.Sprintf("duplicated local variable name: %s", name))
|
|
return nil, false
|
|
}
|
|
}
|
|
}
|
|
t := rhsTypes[i]
|
|
if t.Main == shaderir.None {
|
|
// TODO: This is to determine a type when the rhs values are constants (not literals),
|
|
// but there are no actual cases when len(lhs) != len(rhs). Is this correct?
|
|
t = toDefaultType(rhsExprs[i].Const)
|
|
}
|
|
block.addNamedLocalVariable(name, t, e.Pos())
|
|
}
|
|
|
|
l, _, ss, ok := cs.parseExpr(block, lhs[i], false)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
|
|
if l[0].Type == shaderir.Blank {
|
|
continue
|
|
}
|
|
allblank = false
|
|
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Assign,
|
|
Exprs: []shaderir.Expr{l[0], rhsExprs[i]},
|
|
})
|
|
}
|
|
}
|
|
|
|
if define && allblank {
|
|
cs.addError(pos, fmt.Sprintf("no new variables on left side of :="))
|
|
return nil, false
|
|
}
|
|
|
|
return stmts, true
|
|
}
|
|
|
|
func toDefaultType(v gconstant.Value) shaderir.Type {
|
|
switch v.Kind() {
|
|
case gconstant.Bool:
|
|
return shaderir.Type{Main: shaderir.Bool}
|
|
case gconstant.Int:
|
|
return shaderir.Type{Main: shaderir.Int}
|
|
case gconstant.Float:
|
|
return shaderir.Type{Main: shaderir.Float}
|
|
}
|
|
// TODO: Should this be an error?
|
|
return shaderir.Type{}
|
|
}
|