130cbcfaa3
This makes it more clear that the function isn't about the input the expression *matched* but about the input it *consumed* when it matched. Based on a comment by @Mingun: https://github.com/pegjs/pegjs/pull/307#issuecomment-89512575
30 lines
804 B
JavaScript
30 lines
804 B
JavaScript
"use strict";
|
|
|
|
var GrammarError = require("../../grammar-error"),
|
|
asts = require("../asts"),
|
|
visitor = require("../visitor");
|
|
|
|
/*
|
|
* Reports expressions that don't consume any input inside |*| or |+| in the
|
|
* grammar, which prevents infinite loops in the generated parser.
|
|
*/
|
|
function reportInfiniteLoops(ast) {
|
|
var check = visitor.build({
|
|
zero_or_more: function(node) {
|
|
if (!asts.alwaysAdvancesOnSuccess(ast, node.expression)) {
|
|
throw new GrammarError("Infinite loop detected.", node.location);
|
|
}
|
|
},
|
|
|
|
one_or_more: function(node) {
|
|
if (!asts.alwaysAdvancesOnSuccess(ast, node.expression)) {
|
|
throw new GrammarError("Infinite loop detected.", node.location);
|
|
}
|
|
}
|
|
});
|
|
|
|
check(ast);
|
|
}
|
|
|
|
module.exports = reportInfiniteLoops;
|