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authorGravatar Ron Yorston <rmy@frippery.org>2015-07-01 16:46:18 +0100
committerGravatar Denys Vlasenko <vda.linux@googlemail.com>2015-07-13 04:02:45 +0200
commit072fc60f29ee3a4ff38f095a9ef149b2e820c8c0 (patch)
tree8180cc80c19bca52fe07e8dad8fd69cf84fe545f /shell
parentf54a487bb4d36a4318c5ec539f8265fdff2cac90 (diff)
downloadbusybox-072fc60f29ee3a4ff38f095a9ef149b2e820c8c0.tar.gz
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ash: use alloca to get rid of setjmp
Now that the only thing protected by setjmp/longjmp is the saved string, we can allocate it on the stack to get rid of the jump. Based on commit bd35d8e from git://git.kernel.org/pub/scm/utils/dash/dash.git by Herbert Xu. function old new delta readtoken1 3182 3116 -66 ------------------------------------------------------------------------------ (add/remove: 0/0 grow/shrink: 0/1 up/down: 0/-66) Total: -66 bytes Signed-off-by: Ron Yorston <rmy@frippery.org> Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>
Diffstat (limited to 'shell')
-rw-r--r--shell/ash.c36
1 files changed, 2 insertions, 34 deletions
diff --git a/shell/ash.c b/shell/ash.c
index 6627cec9b..f4779ee2b 100644
--- a/shell/ash.c
+++ b/shell/ash.c
@@ -11132,19 +11132,6 @@ readtoken1(int c, int syntax, char *eofmark, int striptabs)
IF_ASH_BASH_COMPAT(smallint bash_dollar_squote = 0;)
-#if __GNUC__
- /* Avoid longjmp clobbering */
- (void) &out;
- (void) &quotef;
- (void) &dblquote;
- (void) &varnest;
- (void) &arinest;
- (void) &parenlevel;
- (void) &dqvarnest;
- (void) &oldstyle;
- (void) &prevsyntax;
- (void) &syntax;
-#endif
startlinno = g_parsefile->linno;
bqlist = NULL;
quotef = 0;
@@ -11609,30 +11596,16 @@ parsesub: {
parsebackq: {
struct nodelist **nlpp;
union node *n;
- char *volatile str;
- struct jmploc jmploc;
- struct jmploc *volatile savehandler;
+ char *str;
size_t savelen;
smallint saveprompt = 0;
-#ifdef __GNUC__
- (void) &saveprompt;
-#endif
- if (setjmp(jmploc.loc)) {
- free(str);
- exception_handler = savehandler;
- longjmp(exception_handler->loc, 1);
- }
- INT_OFF;
str = NULL;
savelen = out - (char *)stackblock();
if (savelen > 0) {
- str = ckmalloc(savelen);
+ str = alloca(savelen);
memcpy(str, stackblock(), savelen);
}
- savehandler = exception_handler;
- exception_handler = &jmploc;
- INT_ON;
if (oldstyle) {
/* We must read until the closing backquote, giving special
* treatment to some slashes, and then push the string and
@@ -11731,12 +11704,7 @@ parsebackq: {
if (str) {
memcpy(out, str, savelen);
STADJUST(savelen, out);
- INT_OFF;
- free(str);
- str = NULL;
- INT_ON;
}
- exception_handler = savehandler;
USTPUTC(CTLBACKQ, out);
if (oldstyle)
goto parsebackq_oldreturn;