mirror of
https://github.com/hajimehoshi/ebiten.git
synced 2024-12-27 04:08:53 +01:00
837 lines
23 KiB
Go
837 lines
23 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.Const = gconstant.ToInt(expr.Const)
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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, returnType shaderir.Type) ([]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(), "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(), "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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rhs, rts, ss, ok := cs.parseExpr(block, fname, 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, lts, ss, ok := cs.parseExpr(block, fname, 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 lhs[0].Type == shaderir.UniformVariable {
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cs.addError(stmt.Pos(), "a uniform variable cannot be assigned")
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return nil, false
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}
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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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if lts[0].IsMatrix() || rts[0].IsMatrix() {
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op = shaderir.MatrixMul
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} else {
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op = shaderir.ComponentWiseMul
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}
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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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if lts[0].Main == rts[0].Main {
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if op == shaderir.Div && rts[0].IsMatrix() {
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cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: operator / not defined on %s", rts[0].String()))
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return nil, false
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}
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if lts[0].Main == shaderir.Int && rhs[0].Const != nil {
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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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} else {
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switch lts[0].Main {
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case shaderir.Int, shaderir.IVec2, shaderir.IVec3, shaderir.IVec4:
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if rts[0].Main != shaderir.Int {
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if !rts[0].Equal(&shaderir.Type{}) {
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cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: mismatched types %s and %s", lts[0].String(), rts[0].String()))
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return nil, false
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}
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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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case shaderir.Float:
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if rhs[0].Const != nil &&
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(rts[0].Main == shaderir.None || rts[0].Main == shaderir.Float) &&
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gconstant.ToFloat(rhs[0].Const).Kind() != gconstant.Unknown {
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rhs[0].Const = gconstant.ToFloat(rhs[0].Const)
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} else {
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cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: mismatched types %s and %s", lts[0].String(), rts[0].String()))
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return nil, false
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}
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case shaderir.Vec2, shaderir.Vec3, shaderir.Vec4, shaderir.Mat2, shaderir.Mat3, shaderir.Mat4:
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if (op == shaderir.MatrixMul || op == shaderir.Div) &&
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(rts[0].Main == shaderir.Float ||
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(rhs[0].Const != nil &&
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(rts[0].Main == shaderir.None || rts[0].Main == shaderir.Float) &&
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gconstant.ToFloat(rhs[0].Const).Kind() != gconstant.Unknown)) {
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if rhs[0].Const != nil {
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rhs[0].Const = gconstant.ToFloat(rhs[0].Const)
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}
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} else if op == shaderir.MatrixMul && ((lts[0].Main == shaderir.Vec2 && rts[0].Main == shaderir.Mat2) ||
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(lts[0].Main == shaderir.Vec3 && rts[0].Main == shaderir.Mat3) ||
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(lts[0].Main == shaderir.Vec4 && rts[0].Main == shaderir.Mat4)) {
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// OK
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} else if (op == shaderir.MatrixMul || op == shaderir.ComponentWiseMul || lts[0].IsFloatVector()) &&
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(rts[0].Main == shaderir.Float ||
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(rhs[0].Const != nil &&
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(rts[0].Main == shaderir.None || rts[0].Main == shaderir.Float) &&
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gconstant.ToFloat(rhs[0].Const).Kind() != gconstant.Unknown)) {
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if rhs[0].Const != nil {
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rhs[0].Const = gconstant.ToFloat(rhs[0].Const)
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}
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} else {
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cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: mismatched types %s and %s", lts[0].String(), rts[0].String()))
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return nil, false
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}
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default:
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cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: mismatched types %s and %s", lts[0].String(), rts[0].String()))
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return nil, false
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}
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}
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if op == shaderir.ModOp && lts[0].Main != shaderir.Int && lts[0].Main != shaderir.IVec2 && lts[0].Main != shaderir.IVec3 && lts[0].Main != shaderir.IVec4 {
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cs.addError(stmt.Pos(), fmt.Sprintf("invalid operation: operator %% not defined on %s", lts[0].String()))
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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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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, returnType, 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, fname, 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, returnType, 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].Const == 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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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, fname, 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].Const == 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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end := exprs[0].Exprs[1].Const
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postSs, ok := cs.parseStmt(pseudoBlock, fname, stmt.Post, inParams, outParams, returnType)
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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].Const == 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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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, returnType, 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, returnType, 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, fname, 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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|
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var bs []*shaderir.Block
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b, ok := cs.parseBlock(block, fname, stmt.Body.List, inParams, outParams, returnType, 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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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, returnType, 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, returnType, true)
|
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if !ok {
|
|
return nil, false
|
|
}
|
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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, fname, 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,
|
|
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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},
|
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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 != "") {
|
|
// TODO: Check variable shadowings.
|
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// https://go.dev/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)))
|
|
return nil, false
|
|
}
|
|
}
|
|
|
|
var exprs []shaderir.Expr
|
|
var types []shaderir.Type
|
|
for _, r := range stmt.Results {
|
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es, ts, ss, ok := cs.parseExpr(block, fname, r, true)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
|
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if len(es) > 1 && (len(stmt.Results) > 1 || len(outParams) == 1) {
|
|
cs.addError(r.Pos(), "single-value context and multiple-value context cannot be mixed")
|
|
return nil, false
|
|
}
|
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|
|
if len(outParams) > 1 && len(stmt.Results) == 1 {
|
|
if len(es) == 1 {
|
|
cs.addError(stmt.Pos(), fmt.Sprintf("the number of returning variables must be %d but %d", len(outParams), len(stmt.Results)))
|
|
return nil, false
|
|
}
|
|
if len(es) > 1 && len(es) != len(outParams) {
|
|
cs.addError(stmt.Pos(), fmt.Sprintf("the number of returning variables must be %d but %d", len(outParams), len(es)))
|
|
return nil, false
|
|
}
|
|
}
|
|
|
|
exprs = append(exprs, es...)
|
|
types = append(types, ts...)
|
|
}
|
|
|
|
for i, t := range types {
|
|
expr := exprs[i]
|
|
var outT shaderir.Type
|
|
if len(outParams) == 0 {
|
|
outT = returnType
|
|
} else {
|
|
outT = outParams[i].typ
|
|
}
|
|
if expr.Const != nil {
|
|
switch outT.Main {
|
|
case shaderir.Bool:
|
|
if expr.Const.Kind() != gconstant.Bool {
|
|
cs.addError(stmt.Pos(), fmt.Sprintf("cannot use type %s as type %s in return argument", t.String(), &outT))
|
|
return nil, false
|
|
}
|
|
t = shaderir.Type{Main: shaderir.Bool}
|
|
case shaderir.Int:
|
|
if gconstant.ToInt(expr.Const).Kind() == gconstant.Unknown {
|
|
cs.addError(stmt.Pos(), fmt.Sprintf("cannot use type %s as type %s in return argument", t.String(), &outT))
|
|
return nil, false
|
|
}
|
|
expr.Const = gconstant.ToInt(expr.Const)
|
|
t = shaderir.Type{Main: shaderir.Int}
|
|
case shaderir.Float:
|
|
if gconstant.ToFloat(expr.Const).Kind() == gconstant.Unknown {
|
|
cs.addError(stmt.Pos(), fmt.Sprintf("cannot use type %s as type %s in return argument", t.String(), &outT))
|
|
return nil, false
|
|
}
|
|
expr.Const = gconstant.ToFloat(expr.Const)
|
|
t = shaderir.Type{Main: shaderir.Float}
|
|
}
|
|
}
|
|
|
|
if !t.Equal(&outT) {
|
|
cs.addError(stmt.Pos(), fmt.Sprintf("cannot use type %s as type %s in return argument", t.String(), &outT))
|
|
return nil, false
|
|
}
|
|
|
|
if len(outParams) > 0 {
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Assign,
|
|
Exprs: []shaderir.Expr{
|
|
{
|
|
Type: shaderir.LocalVariable,
|
|
Index: len(inParams) + i,
|
|
},
|
|
expr,
|
|
},
|
|
})
|
|
} else {
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Return,
|
|
Exprs: []shaderir.Expr{expr},
|
|
})
|
|
// When a return type is specified, there should be only one expr here.
|
|
break
|
|
}
|
|
}
|
|
|
|
if len(outParams) > 0 {
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Return,
|
|
})
|
|
}
|
|
|
|
case *ast.BranchStmt:
|
|
switch stmt.Tok {
|
|
case token.BREAK:
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Break,
|
|
})
|
|
case token.CONTINUE:
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Continue,
|
|
})
|
|
default:
|
|
cs.addError(stmt.Pos(), fmt.Sprintf("invalid token: %s", stmt.Tok))
|
|
return nil, false
|
|
}
|
|
|
|
case *ast.ExprStmt:
|
|
if _, ok := stmt.X.(*ast.CallExpr); !ok {
|
|
cs.addError(stmt.Pos(), "the statement is evaluated but not used")
|
|
return nil, false
|
|
}
|
|
|
|
exprs, _, ss, ok := cs.parseExpr(block, fname, stmt.X, true)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
|
|
for _, expr := range exprs {
|
|
// There can be a non-call expr like LocalVariable expressions.
|
|
// These are necessary to be used as arguments for an outside function callers.
|
|
if expr.Type != shaderir.Call {
|
|
continue
|
|
}
|
|
if expr.Exprs[0].Type == shaderir.BuiltinFuncExpr {
|
|
cs.addError(stmt.Pos(), "the statement is evaluated but not used")
|
|
return nil, false
|
|
}
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.ExprStmt,
|
|
Exprs: []shaderir.Expr{expr},
|
|
})
|
|
}
|
|
|
|
default:
|
|
cs.addError(stmt.Pos(), fmt.Sprintf("unexpected statement: %#v", stmt))
|
|
return nil, false
|
|
}
|
|
return stmts, true
|
|
}
|
|
|
|
func (cs *compileState) assign(block *block, fname string, pos token.Pos, lhs, rhs []ast.Expr, inParams []variable, define bool) ([]shaderir.Stmt, bool) {
|
|
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, rts, ss, ok := cs.parseExpr(block, fname, 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 = rts
|
|
}
|
|
if len(ts) > 1 {
|
|
cs.addError(pos, "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, "single-value context and multiple-value context cannot be mixed")
|
|
return nil, false
|
|
}
|
|
|
|
l, lts, ss, ok := cs.parseExpr(block, fname, lhs[i], false)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
|
|
if len(l) != len(r) {
|
|
if len(r) == 0 {
|
|
cs.addError(pos, "right-hand side (no value) used as value")
|
|
} else {
|
|
cs.addError(pos, fmt.Sprintf("assignment mismatch: %d variables but the right-hand side has %d values", len(l), len(r)))
|
|
}
|
|
return nil, false
|
|
}
|
|
|
|
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, "a uniform variable cannot be assigned")
|
|
return nil, false
|
|
}
|
|
allblank = false
|
|
|
|
for i := range lts {
|
|
if !canAssign(<s[i], &rts[i], r[i].Const) {
|
|
cs.addError(pos, fmt.Sprintf("cannot use type %s as type %s in variable declaration", rts[i].String(), lts[i].String()))
|
|
return nil, false
|
|
}
|
|
}
|
|
|
|
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 := rts[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, fname, rhs[0], true)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
if len(rhsExprs) != len(lhs) {
|
|
cs.addError(pos, "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, lts, ss, ok := cs.parseExpr(block, fname, lhs[i], false)
|
|
if !ok {
|
|
return nil, false
|
|
}
|
|
stmts = append(stmts, ss...)
|
|
|
|
if l[0].Type == shaderir.Blank {
|
|
continue
|
|
}
|
|
allblank = false
|
|
|
|
for i, lt := range lts {
|
|
if !canAssign(<, &rhsTypes[i], rhsExprs[i].Const) {
|
|
cs.addError(pos, fmt.Sprintf("cannot use type %s as type %s in variable declaration", rhsTypes[i].String(), lt.String()))
|
|
return nil, false
|
|
}
|
|
}
|
|
|
|
stmts = append(stmts, shaderir.Stmt{
|
|
Type: shaderir.Assign,
|
|
Exprs: []shaderir.Expr{l[0], rhsExprs[i]},
|
|
})
|
|
}
|
|
}
|
|
|
|
if define && allblank {
|
|
cs.addError(pos, "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{}
|
|
}
|
|
|
|
func canAssign(lt *shaderir.Type, rt *shaderir.Type, rc gconstant.Value) bool {
|
|
if lt.Equal(rt) {
|
|
return true
|
|
}
|
|
|
|
if rc == nil {
|
|
return false
|
|
}
|
|
|
|
if !rt.Equal(&shaderir.Type{}) {
|
|
return false
|
|
}
|
|
|
|
switch lt.Main {
|
|
case shaderir.Bool:
|
|
return rc.Kind() == gconstant.Bool
|
|
case shaderir.Int:
|
|
return gconstant.ToInt(rc).Kind() != gconstant.Unknown
|
|
case shaderir.Float:
|
|
return gconstant.ToFloat(rc).Kind() != gconstant.Unknown
|
|
}
|
|
|
|
return false
|
|
}
|