ash: parser: Add syntax stack for recursive parsing

2018-04-02T11:15:37+00:00

This closes 10821. Upstream patch: From: Herbert Xu Date: Fri, 9 Mar 2018 00:14:02 +0800 parser: Add syntax stack for recursive parsing Without a stack of syntaxes we cannot correctly these two cases together: "${a#'$$'}" "${a#"${b-'$$'}"}" A recursive parser also helps in some other corner cases such as nested arithmetic expansion with paratheses. This patch adds a syntax stack allocated from the stack using alloca. As a side-effect this allows us to remove the naked backslashes for patterns within double-quotes, which means that EXP_QPAT also has to go. This patch also fixes removes any backslashes that precede right braces when they are present within a parameter expansion context, and backslashes that precede double quotes within inner double quotes inside a parameter expansion in a here-document context. The idea of a recursive parser is based on a patch by Harald van Dijk. Signed-off-by: Herbert Xu var_bash3, var_bash4 and var_bash6 tests are updated with the output given by bash-4.3.43 With this patch, the following tests now pass for ash: dollar_repl_slash_bash2.tests squote_in_varexp2.tests squote_in_varexp.tests var_bash4.tests function old new delta readtoken1 2615 2874 +259 synstack_push - 54 +54 evalvar 574 571 -3 rmescapes 330 310 -20 subevalvar 1279 1258 -21 argstr 1146 1107 -39 ------------------------------------------------------------------------------ (add/remove: 1/0 grow/shrink: 1/4 up/down: 313/-83) Total: 230 bytes Signed-off-by: Denys Vlasenko

hush: implement negative start in the ${v: -n[:m]} idiom

2017-07-06T17:48:20+00:00

Signed-off-by: Denys Vlasenko

busybox-w32/shell/ash_test/ash-vars/var_bash6.tests, branch cron_changes

ash: parser: Add syntax stack for recursive parsing

hush: implement negative start in the ${v: -n[:m]} idiom