mirror of
https://github.com/vlang/v.git
synced 2023-08-10 21:13:21 +03:00
382 lines
9.3 KiB
V
382 lines
9.3 KiB
V
// Copyright (c) 2019-2022 Alexander Medvednikov. All rights reserved.
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// Use of this source code is governed by an MIT license
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// that can be found in the LICENSE file.
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module parser
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import v.ast
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fn (mut p Parser) assign_stmt() ast.Stmt {
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mut defer_vars := p.defer_vars
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p.defer_vars = []ast.Ident{}
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exprs, comments := p.expr_list()
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if !(p.inside_defer && p.tok.kind == .decl_assign) {
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defer_vars << p.defer_vars
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}
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p.defer_vars = defer_vars
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return p.partial_assign_stmt(exprs, comments)
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}
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const max_expr_level = 100
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fn (mut p Parser) check_undefined_variables(exprs []ast.Expr, val ast.Expr) ? {
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p.expr_level++
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defer {
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p.expr_level--
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}
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if p.expr_level > parser.max_expr_level {
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return error('expr level > $parser.max_expr_level')
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}
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match val {
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ast.Ident {
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for expr in exprs {
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if expr is ast.Ident {
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if expr.name == val.name && expr.kind != .blank_ident {
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p.error_with_pos('undefined variable: `$val.name`', val.pos)
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return error('undefined variable: `$val.name`')
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}
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}
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}
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}
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ast.ArrayInit {
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if val.has_cap {
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p.check_undefined_variables(exprs, val.cap_expr)?
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}
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if val.has_len {
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p.check_undefined_variables(exprs, val.len_expr)?
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}
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if val.has_default {
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p.check_undefined_variables(exprs, val.default_expr)?
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}
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for expr in val.exprs {
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p.check_undefined_variables(exprs, expr)?
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}
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}
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ast.CallExpr {
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p.check_undefined_variables(exprs, val.left)?
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for arg in val.args {
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p.check_undefined_variables(exprs, arg.expr)?
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}
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}
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ast.InfixExpr {
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p.check_undefined_variables(exprs, val.left)?
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p.check_undefined_variables(exprs, val.right)?
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}
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ast.IfExpr {
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p.check_undefined_variables(exprs, val.left)?
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for branch in val.branches {
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p.check_undefined_variables(exprs, branch.cond)?
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for stmt in branch.stmts {
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if stmt is ast.ExprStmt {
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p.check_undefined_variables(exprs, stmt.expr)?
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}
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}
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}
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}
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ast.MapInit {
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for key in val.keys {
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p.check_undefined_variables(exprs, key)?
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}
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for value in val.vals {
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p.check_undefined_variables(exprs, value)?
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}
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}
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ast.MatchExpr {
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p.check_undefined_variables(exprs, val.cond)?
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for branch in val.branches {
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for expr in branch.exprs {
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p.check_undefined_variables(exprs, expr)?
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}
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for stmt in branch.stmts {
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if stmt is ast.ExprStmt {
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p.check_undefined_variables(exprs, stmt.expr)?
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}
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}
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}
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}
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ast.ParExpr {
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p.check_undefined_variables(exprs, val.expr)?
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}
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ast.PostfixExpr {
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p.check_undefined_variables(exprs, val.expr)?
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}
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ast.PrefixExpr {
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p.check_undefined_variables(exprs, val.right)?
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}
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ast.StringInterLiteral {
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for expr_ in val.exprs {
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p.check_undefined_variables(exprs, expr_)?
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}
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}
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ast.StructInit {
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for field in val.fields {
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p.check_undefined_variables(exprs, field.expr)?
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}
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}
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else {}
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}
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}
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fn (mut p Parser) check_undefined_variables_by_names(names []string, val ast.Expr) ? {
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p.expr_level++
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defer {
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p.expr_level--
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}
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if p.expr_level > parser.max_expr_level {
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return error('expr level > $parser.max_expr_level')
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}
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match val {
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ast.Ident {
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for name in names {
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if name == val.name && val.kind != .blank_ident {
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p.error_with_pos('undefined variable: `$val.name`', val.pos)
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return error('undefined variable: `$val.name`')
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}
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}
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}
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ast.ArrayInit {
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if val.has_cap {
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p.check_undefined_variables_by_names(names, val.cap_expr)?
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}
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if val.has_len {
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p.check_undefined_variables_by_names(names, val.len_expr)?
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}
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if val.has_default {
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p.check_undefined_variables_by_names(names, val.default_expr)?
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}
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for expr in val.exprs {
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p.check_undefined_variables_by_names(names, expr)?
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}
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}
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ast.CallExpr {
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p.check_undefined_variables_by_names(names, val.left)?
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for arg in val.args {
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p.check_undefined_variables_by_names(names, arg.expr)?
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}
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}
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ast.InfixExpr {
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p.check_undefined_variables_by_names(names, val.left)?
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p.check_undefined_variables_by_names(names, val.right)?
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}
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ast.IfExpr {
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p.check_undefined_variables_by_names(names, val.left)?
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for branch in val.branches {
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p.check_undefined_variables_by_names(names, branch.cond)?
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for stmt in branch.stmts {
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if stmt is ast.ExprStmt {
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p.check_undefined_variables_by_names(names, stmt.expr)?
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}
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}
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}
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}
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ast.MapInit {
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for key in val.keys {
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p.check_undefined_variables_by_names(names, key)?
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}
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for value in val.vals {
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p.check_undefined_variables_by_names(names, value)?
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}
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}
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ast.MatchExpr {
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p.check_undefined_variables_by_names(names, val.cond)?
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for branch in val.branches {
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for expr in branch.exprs {
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p.check_undefined_variables_by_names(names, expr)?
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}
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for stmt in branch.stmts {
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if stmt is ast.ExprStmt {
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p.check_undefined_variables_by_names(names, stmt.expr)?
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}
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}
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}
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}
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ast.ParExpr {
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p.check_undefined_variables_by_names(names, val.expr)?
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}
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ast.PostfixExpr {
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p.check_undefined_variables_by_names(names, val.expr)?
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}
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ast.PrefixExpr {
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p.check_undefined_variables_by_names(names, val.right)?
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}
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ast.StringInterLiteral {
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for expr_ in val.exprs {
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p.check_undefined_variables_by_names(names, expr_)?
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}
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}
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ast.StructInit {
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for field in val.fields {
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p.check_undefined_variables_by_names(names, field.expr)?
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}
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}
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else {}
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}
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}
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fn (mut p Parser) check_cross_variables(exprs []ast.Expr, val ast.Expr) bool {
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val_str := val.str()
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match val {
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ast.Ident {
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for expr in exprs {
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if expr is ast.Ident {
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if expr.name == val.name {
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return true
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}
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}
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}
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}
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ast.IndexExpr {
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for expr in exprs {
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if expr.str() == val_str {
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return true
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}
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}
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}
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ast.InfixExpr {
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return p.check_cross_variables(exprs, val.left)
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|| p.check_cross_variables(exprs, val.right)
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}
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ast.ParExpr {
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return p.check_cross_variables(exprs, val.expr)
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}
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ast.CallExpr {
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for arg in val.args {
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if p.check_cross_variables(exprs, arg.expr) {
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return true
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}
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}
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}
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ast.PrefixExpr {
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return p.check_cross_variables(exprs, val.right)
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}
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ast.PostfixExpr {
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return p.check_cross_variables(exprs, val.expr)
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}
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ast.SelectorExpr {
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for expr in exprs {
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if expr.str() == val_str {
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return true
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}
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}
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}
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else {}
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}
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return false
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}
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fn (mut p Parser) partial_assign_stmt(left []ast.Expr, left_comments []ast.Comment) ast.Stmt {
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p.is_stmt_ident = false
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op := p.tok.kind
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mut pos := p.tok.pos()
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p.next()
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mut comments := []ast.Comment{cap: 2 * left_comments.len + 1}
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comments << left_comments
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comments << p.eat_comments()
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mut right_comments := []ast.Comment{}
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mut right := []ast.Expr{cap: left.len}
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right, right_comments = p.expr_list()
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comments << right_comments
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end_comments := p.eat_comments(same_line: true)
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mut has_cross_var := false
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mut is_static := false
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mut is_volatile := false
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for i, lx_ in left {
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mut lx := unsafe { lx_ }
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match mut lx {
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ast.Ident {
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if op == .decl_assign {
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if p.scope.known_var(lx.name) {
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return p.error_with_pos('redefinition of `$lx.name`', lx.pos)
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}
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mut share := ast.ShareType(0)
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if mut lx.info is ast.IdentVar {
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share = lx.info.share
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if lx.info.is_static {
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if !p.pref.translated && !p.is_translated && !p.pref.is_fmt
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&& !p.inside_unsafe_fn {
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return p.error_with_pos('static variables are supported only in translated mode or in [unsafe] fn',
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lx.pos)
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}
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is_static = true
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}
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if lx.info.is_volatile {
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is_volatile = true
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}
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}
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mut v := ast.Var{
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name: lx.name
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expr: if left.len == right.len { right[i] } else { ast.empty_expr }
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share: share
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is_mut: lx.is_mut || p.inside_for
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pos: lx.pos
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is_stack_obj: p.inside_for
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}
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if p.pref.autofree {
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r0 := right[0]
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if r0 is ast.CallExpr {
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// Set correct variable position (after the or block)
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// so that autofree doesn't free it in cgen before
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// it's declared. (`Or` variables are declared after the or block).
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if r0.or_block.pos.pos > 0 && r0.or_block.stmts.len > 0 {
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v.is_or = true
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// v.pos = r0.or_block.pos.
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}
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}
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}
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obj := ast.ScopeObject(v)
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lx.obj = obj
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p.scope.register(obj)
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}
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}
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ast.IndexExpr {
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if op == .decl_assign {
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return p.error_with_pos('non-name `$lx.left[$lx.index]` on left side of `:=`',
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lx.pos)
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}
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lx.is_setter = true
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}
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ast.ParExpr {}
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ast.PrefixExpr {}
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ast.SelectorExpr {
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if op == .decl_assign {
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return p.error_with_pos('use assignment `=` instead of declaration `:=` when modifying struct fields',
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pos)
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}
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}
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else {}
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}
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}
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if op == .decl_assign {
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// a, b := a + 1, b
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for r in right {
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p.check_undefined_variables(left, r) or { return p.error_with_pos(err.msg(), pos) }
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}
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} else if left.len > 1 {
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// a, b = b, a
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for r in right {
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has_cross_var = p.check_cross_variables(left, r)
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if op !in [.assign, .decl_assign] {
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return p.error_with_pos('unexpected $op.str(), expecting := or = or comma',
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pos)
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}
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if has_cross_var {
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break
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}
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}
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}
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pos.update_last_line(p.prev_tok.line_nr)
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return ast.AssignStmt{
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op: op
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left: left
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right: right
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comments: comments
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end_comments: end_comments
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pos: pos
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has_cross_var: has_cross_var
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is_simple: p.inside_for && p.tok.kind == .lcbr
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is_static: is_static
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is_volatile: is_volatile
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}
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}
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