ash: parser: Add syntax stack for recursive parsing
This closes 10821.
Upstream patch:
From: Herbert Xu <herbert@gondor.apana.org.au>
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 <herbert@gondor.apana.org.au>
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 <vda.linux@googlemail.com>
diff --git a/shell/hush_test/hush-vars/var_bash4.right b/shell/hush_test/hush-vars/var_bash4.right
index 0ef1bf6..9067e58 100644
--- a/shell/hush_test/hush-vars/var_bash4.right
+++ b/shell/hush_test/hush-vars/var_bash4.right
@@ -3,26 +3,26 @@
Pattern: single backslash and star: "replace literal star"
Unquoted: a_\_z_b\*c
Unquoted =: a_\_z_b\*c
-Quoted: a_\_\z_b\*c
-Quoted =: a_\_\z_b\*c
+Quoted: a_\_z_b\*c
+Quoted =: a_\_z_b\*c
Pattern: double backslash and star: "replace backslash and everything after it"
Unquoted: a*b_\_z_
Unquoted =: a*b_\_z_
-Quoted: a*b_\_\z_
-Quoted =: a*b_\_\z_
+Quoted: a*b_\_z_
+Quoted =: a*b_\_z_
Source: a\bc
Replace str: _\\_\z_
Pattern: single backslash and b: "replace b"
Unquoted: a\_\_z_c
Unquoted =: a\_\_z_c
-Quoted: a\_\_\z_c
-Quoted =: a\_\_\z_c
+Quoted: a\_\_z_c
+Quoted =: a\_\_z_c
Pattern: double backslash and b: "replace backslash and b"
Unquoted: a_\_z_c
Unquoted =: a_\_z_c
-Quoted: a_\_\z_c
-Quoted =: a_\_\z_c
+Quoted: a_\_z_c
+Quoted =: a_\_z_c
Source: a\bc
Replace str: _\\_\z_ (as variable $s)