configure | 18 ++++++++++++++++++ hmp.c | 8 ++++---- hw/9pfs/9p-local.c | 2 +- include/qemu/cutils.h | 8 ++++++++ monitor.c | 8 ++------ util/cutils.c | 15 +++++++++++++++ util/qemu-option.c | 6 +----- util/uri.c | 6 ++---- 8 files changed, 51 insertions(+), 20 deletions(-)
strchrnul is a GNU extension and thus unavailable on a number of targets.
In the review for a commit removing strchrnul from 9p, I was asked to
create a qemu_strchrnul helper to factor out this functionality.
Do so, and use it in a number of other places in the code base that inlined
the replacement pattern in a place where strchrnul could be used.
Signed-off-by: Keno Fischer <keno@juliacomputing.com>
Acked-by: Greg Kurz <groug@kaod.org>
---
Changes since v4:
- `CONFIG_STRCHRNUL` -> `HAVE_STRCHRNUL` name change
- In the strchrnul configure check
- Return the value of strchrnul to avoid it being optimized away
- Use `&main` (i.e. the assembly of the generated function as
the haystack) to avoid concerns about constant folding. `main`
seemed like the simplest symbol guaranteed to exist, but with
non-foldable content.
configure | 18 ++++++++++++++++++
hmp.c | 8 ++++----
hw/9pfs/9p-local.c | 2 +-
include/qemu/cutils.h | 8 ++++++++
monitor.c | 8 ++------
util/cutils.c | 15 +++++++++++++++
util/qemu-option.c | 6 +-----
util/uri.c | 6 ++----
8 files changed, 51 insertions(+), 20 deletions(-)
diff --git a/configure b/configure
index 14b1113..8a75745 100755
--- a/configure
+++ b/configure
@@ -4747,6 +4747,21 @@ if compile_prog "" "" ; then
fi
##########################################
+# check if we have strchrnul
+
+strchrnul=no
+cat > $TMPC << EOF
+#include <string.h>
+int main(void);
+// Use a haystack that the compiler shouldn't be able to constant fold
+char *haystack = (char*)&main;
+int main(void) { return strchrnul(haystack, 'x') != &haystack[6]; }
+EOF
+if compile_prog "" "" ; then
+ strchrnul=yes
+fi
+
+##########################################
# check if trace backend exists
$python "$source_path/scripts/tracetool.py" "--backends=$trace_backends" --check-backends > /dev/null 2> /dev/null
@@ -6229,6 +6244,9 @@ fi
if test "$sem_timedwait" = "yes" ; then
echo "CONFIG_SEM_TIMEDWAIT=y" >> $config_host_mak
fi
+if test "$strchrnul" = "yes" ; then
+ echo "HAVE_STRCHRNUL=y" >> $config_host_mak
+fi
if test "$byteswap_h" = "yes" ; then
echo "CONFIG_BYTESWAP_H=y" >> $config_host_mak
fi
diff --git a/hmp.c b/hmp.c
index ef93f48..416d4c9 100644
--- a/hmp.c
+++ b/hmp.c
@@ -2123,12 +2123,12 @@ void hmp_sendkey(Monitor *mon, const QDict *qdict)
int has_hold_time = qdict_haskey(qdict, "hold-time");
int hold_time = qdict_get_try_int(qdict, "hold-time", -1);
Error *err = NULL;
- char *separator;
+ const char *separator;
int keyname_len;
while (1) {
- separator = strchr(keys, '-');
- keyname_len = separator ? separator - keys : strlen(keys);
+ separator = qemu_strchrnul(keys, '-');
+ keyname_len = separator - keys;
/* Be compatible with old interface, convert user inputted "<" */
if (keys[0] == '<' && keyname_len == 1) {
@@ -2165,7 +2165,7 @@ void hmp_sendkey(Monitor *mon, const QDict *qdict)
keylist->value->u.qcode.data = idx;
}
- if (!separator) {
+ if (!*separator) {
break;
}
keys = separator + 1;
diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c
index 5721eff..828e8d6 100644
--- a/hw/9pfs/9p-local.c
+++ b/hw/9pfs/9p-local.c
@@ -65,7 +65,7 @@ int local_open_nofollow(FsContext *fs_ctx, const char *path, int flags,
assert(*path != '/');
head = g_strdup(path);
- c = strchrnul(path, '/');
+ c = qemu_strchrnul(path, '/');
if (*c) {
/* Intermediate path element */
head[c - path] = 0;
diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h
index a663340..274d419 100644
--- a/include/qemu/cutils.h
+++ b/include/qemu/cutils.h
@@ -122,6 +122,14 @@ int qemu_strnlen(const char *s, int max_len);
* Returns: the pointer originally in @input.
*/
char *qemu_strsep(char **input, const char *delim);
+#ifdef HAVE_STRCHRNUL
+static inline const char *qemu_strchrnul(const char *s, int c)
+{
+ return strchrnul(s, c);
+}
+#else
+const char *qemu_strchrnul(const char *s, int c);
+#endif
time_t mktimegm(struct tm *tm);
int qemu_fdatasync(int fd);
int fcntl_setfl(int fd, int flag);
diff --git a/monitor.c b/monitor.c
index 6d0cec5..4484d74 100644
--- a/monitor.c
+++ b/monitor.c
@@ -797,9 +797,7 @@ static int compare_cmd(const char *name, const char *list)
p = list;
for(;;) {
pstart = p;
- p = strchr(p, '|');
- if (!p)
- p = pstart + strlen(pstart);
+ p = qemu_strchrnul(p, '|');
if ((p - pstart) == len && !memcmp(pstart, name, len))
return 1;
if (*p == '\0')
@@ -3400,9 +3398,7 @@ static void cmd_completion(Monitor *mon, const char *name, const char *list)
p = list;
for(;;) {
pstart = p;
- p = strchr(p, '|');
- if (!p)
- p = pstart + strlen(pstart);
+ p = qemu_strchrnul(p, '|');
len = p - pstart;
if (len > sizeof(cmd) - 2)
len = sizeof(cmd) - 2;
diff --git a/util/cutils.c b/util/cutils.c
index 0de69e6..9205e09 100644
--- a/util/cutils.c
+++ b/util/cutils.c
@@ -545,6 +545,21 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base,
}
/**
+ * Searches for the first occurrence of 'c' in 's', and returns a pointer
+ * to the trailing null byte if none was found.
+ */
+#ifndef HAVE_STRCHRNUL
+const char *qemu_strchrnul(const char *s, int c)
+{
+ const char *e = strchr(s, c);
+ if (!e) {
+ e = s + strlen(s);
+ }
+ return e;
+}
+#endif
+
+/**
* parse_uint:
*
* @s: String to parse
diff --git a/util/qemu-option.c b/util/qemu-option.c
index 58d1c23..54eca12 100644
--- a/util/qemu-option.c
+++ b/util/qemu-option.c
@@ -77,11 +77,7 @@ const char *get_opt_value(const char *p, char **value)
*value = NULL;
while (1) {
- offset = strchr(p, ',');
- if (!offset) {
- offset = p + strlen(p);
- }
-
+ offset = qemu_strchrnul(p, ',');
length = offset - p;
if (*offset != '\0' && *(offset + 1) == ',') {
length++;
diff --git a/util/uri.c b/util/uri.c
index 8624a7a..8bdef84 100644
--- a/util/uri.c
+++ b/util/uri.c
@@ -52,6 +52,7 @@
*/
#include "qemu/osdep.h"
+#include "qemu/cutils.h"
#include "qemu/uri.h"
@@ -2266,10 +2267,7 @@ struct QueryParams *query_params_parse(const char *query)
/* Find the next separator, or end of the string. */
end = strchr(query, '&');
if (!end) {
- end = strchr(query, ';');
- }
- if (!end) {
- end = query + strlen(query);
+ end = qemu_strchrnul(query, ';');
}
/* Find the first '=' character between here and end. */
--
2.8.1
Keno Fischer <keno@juliacomputing.com> writes: > strchrnul is a GNU extension and thus unavailable on a number of targets. > In the review for a commit removing strchrnul from 9p, I was asked to > create a qemu_strchrnul helper to factor out this functionality. > Do so, and use it in a number of other places in the code base that inlined > the replacement pattern in a place where strchrnul could be used. > > Signed-off-by: Keno Fischer <keno@juliacomputing.com> > Acked-by: Greg Kurz <groug@kaod.org> Reviewed-by: Markus Armbruster <armbru@redhat.com>
On Wed, 13 Jun 2018 07:42:57 +0200 Markus Armbruster <armbru@redhat.com> wrote: > Keno Fischer <keno@juliacomputing.com> writes: > > > strchrnul is a GNU extension and thus unavailable on a number of targets. > > In the review for a commit removing strchrnul from 9p, I was asked to > > create a qemu_strchrnul helper to factor out this functionality. > > Do so, and use it in a number of other places in the code base that inlined > > the replacement pattern in a place where strchrnul could be used. > > > > Signed-off-by: Keno Fischer <keno@juliacomputing.com> > > Acked-by: Greg Kurz <groug@kaod.org> > > Reviewed-by: Markus Armbruster <armbru@redhat.com> Maybe I can take this through my 9p-next tree since it is a pre-requisite for the Darwin support series ? Keno, BTW, if you want Darwin support to go in the next QEMU release, please pay attention that I have to send a pull req for it before 2018-07-03. https://wiki.qemu.org/Planning/3.0 Cheers, -- Greg
Greg Kurz <groug@kaod.org> writes: > On Wed, 13 Jun 2018 07:42:57 +0200 > Markus Armbruster <armbru@redhat.com> wrote: > >> Keno Fischer <keno@juliacomputing.com> writes: >> >> > strchrnul is a GNU extension and thus unavailable on a number of targets. >> > In the review for a commit removing strchrnul from 9p, I was asked to >> > create a qemu_strchrnul helper to factor out this functionality. >> > Do so, and use it in a number of other places in the code base that inlined >> > the replacement pattern in a place where strchrnul could be used. >> > >> > Signed-off-by: Keno Fischer <keno@juliacomputing.com> >> > Acked-by: Greg Kurz <groug@kaod.org> >> >> Reviewed-by: Markus Armbruster <armbru@redhat.com> > > Maybe I can take this through my 9p-next tree since it is a pre-requisite > for the Darwin support series ? Go ahead :) [...]
On Tue, 12 Jun 2018 23:48:31 -0400 Keno Fischer <keno@juliacomputing.com> wrote: > strchrnul is a GNU extension and thus unavailable on a number of targets. > In the review for a commit removing strchrnul from 9p, I was asked to > create a qemu_strchrnul helper to factor out this functionality. > Do so, and use it in a number of other places in the code base that inlined > the replacement pattern in a place where strchrnul could be used. > > Signed-off-by: Keno Fischer <keno@juliacomputing.com> > Acked-by: Greg Kurz <groug@kaod.org> > --- > Applied to 9p-next. You can rebase your patches against: https://github.com/gkurz/qemu/commits/9p-next Thanks! > Changes since v4: > - `CONFIG_STRCHRNUL` -> `HAVE_STRCHRNUL` name change > - In the strchrnul configure check > - Return the value of strchrnul to avoid it being optimized away > - Use `&main` (i.e. the assembly of the generated function as > the haystack) to avoid concerns about constant folding. `main` > seemed like the simplest symbol guaranteed to exist, but with > non-foldable content. > > configure | 18 ++++++++++++++++++ > hmp.c | 8 ++++---- > hw/9pfs/9p-local.c | 2 +- > include/qemu/cutils.h | 8 ++++++++ > monitor.c | 8 ++------ > util/cutils.c | 15 +++++++++++++++ > util/qemu-option.c | 6 +----- > util/uri.c | 6 ++---- > 8 files changed, 51 insertions(+), 20 deletions(-) > > diff --git a/configure b/configure > index 14b1113..8a75745 100755 > --- a/configure > +++ b/configure > @@ -4747,6 +4747,21 @@ if compile_prog "" "" ; then > fi > > ########################################## > +# check if we have strchrnul > + > +strchrnul=no > +cat > $TMPC << EOF > +#include <string.h> > +int main(void); > +// Use a haystack that the compiler shouldn't be able to constant fold > +char *haystack = (char*)&main; > +int main(void) { return strchrnul(haystack, 'x') != &haystack[6]; } > +EOF > +if compile_prog "" "" ; then > + strchrnul=yes > +fi > + > +########################################## > # check if trace backend exists > > $python "$source_path/scripts/tracetool.py" "--backends=$trace_backends" --check-backends > /dev/null 2> /dev/null > @@ -6229,6 +6244,9 @@ fi > if test "$sem_timedwait" = "yes" ; then > echo "CONFIG_SEM_TIMEDWAIT=y" >> $config_host_mak > fi > +if test "$strchrnul" = "yes" ; then > + echo "HAVE_STRCHRNUL=y" >> $config_host_mak > +fi > if test "$byteswap_h" = "yes" ; then > echo "CONFIG_BYTESWAP_H=y" >> $config_host_mak > fi > diff --git a/hmp.c b/hmp.c > index ef93f48..416d4c9 100644 > --- a/hmp.c > +++ b/hmp.c > @@ -2123,12 +2123,12 @@ void hmp_sendkey(Monitor *mon, const QDict *qdict) > int has_hold_time = qdict_haskey(qdict, "hold-time"); > int hold_time = qdict_get_try_int(qdict, "hold-time", -1); > Error *err = NULL; > - char *separator; > + const char *separator; > int keyname_len; > > while (1) { > - separator = strchr(keys, '-'); > - keyname_len = separator ? separator - keys : strlen(keys); > + separator = qemu_strchrnul(keys, '-'); > + keyname_len = separator - keys; > > /* Be compatible with old interface, convert user inputted "<" */ > if (keys[0] == '<' && keyname_len == 1) { > @@ -2165,7 +2165,7 @@ void hmp_sendkey(Monitor *mon, const QDict *qdict) > keylist->value->u.qcode.data = idx; > } > > - if (!separator) { > + if (!*separator) { > break; > } > keys = separator + 1; > diff --git a/hw/9pfs/9p-local.c b/hw/9pfs/9p-local.c > index 5721eff..828e8d6 100644 > --- a/hw/9pfs/9p-local.c > +++ b/hw/9pfs/9p-local.c > @@ -65,7 +65,7 @@ int local_open_nofollow(FsContext *fs_ctx, const char *path, int flags, > assert(*path != '/'); > > head = g_strdup(path); > - c = strchrnul(path, '/'); > + c = qemu_strchrnul(path, '/'); > if (*c) { > /* Intermediate path element */ > head[c - path] = 0; > diff --git a/include/qemu/cutils.h b/include/qemu/cutils.h > index a663340..274d419 100644 > --- a/include/qemu/cutils.h > +++ b/include/qemu/cutils.h > @@ -122,6 +122,14 @@ int qemu_strnlen(const char *s, int max_len); > * Returns: the pointer originally in @input. > */ > char *qemu_strsep(char **input, const char *delim); > +#ifdef HAVE_STRCHRNUL > +static inline const char *qemu_strchrnul(const char *s, int c) > +{ > + return strchrnul(s, c); > +} > +#else > +const char *qemu_strchrnul(const char *s, int c); > +#endif > time_t mktimegm(struct tm *tm); > int qemu_fdatasync(int fd); > int fcntl_setfl(int fd, int flag); > diff --git a/monitor.c b/monitor.c > index 6d0cec5..4484d74 100644 > --- a/monitor.c > +++ b/monitor.c > @@ -797,9 +797,7 @@ static int compare_cmd(const char *name, const char *list) > p = list; > for(;;) { > pstart = p; > - p = strchr(p, '|'); > - if (!p) > - p = pstart + strlen(pstart); > + p = qemu_strchrnul(p, '|'); > if ((p - pstart) == len && !memcmp(pstart, name, len)) > return 1; > if (*p == '\0') > @@ -3400,9 +3398,7 @@ static void cmd_completion(Monitor *mon, const char *name, const char *list) > p = list; > for(;;) { > pstart = p; > - p = strchr(p, '|'); > - if (!p) > - p = pstart + strlen(pstart); > + p = qemu_strchrnul(p, '|'); > len = p - pstart; > if (len > sizeof(cmd) - 2) > len = sizeof(cmd) - 2; > diff --git a/util/cutils.c b/util/cutils.c > index 0de69e6..9205e09 100644 > --- a/util/cutils.c > +++ b/util/cutils.c > @@ -545,6 +545,21 @@ int qemu_strtou64(const char *nptr, const char **endptr, int base, > } > > /** > + * Searches for the first occurrence of 'c' in 's', and returns a pointer > + * to the trailing null byte if none was found. > + */ > +#ifndef HAVE_STRCHRNUL > +const char *qemu_strchrnul(const char *s, int c) > +{ > + const char *e = strchr(s, c); > + if (!e) { > + e = s + strlen(s); > + } > + return e; > +} > +#endif > + > +/** > * parse_uint: > * > * @s: String to parse > diff --git a/util/qemu-option.c b/util/qemu-option.c > index 58d1c23..54eca12 100644 > --- a/util/qemu-option.c > +++ b/util/qemu-option.c > @@ -77,11 +77,7 @@ const char *get_opt_value(const char *p, char **value) > > *value = NULL; > while (1) { > - offset = strchr(p, ','); > - if (!offset) { > - offset = p + strlen(p); > - } > - > + offset = qemu_strchrnul(p, ','); > length = offset - p; > if (*offset != '\0' && *(offset + 1) == ',') { > length++; > diff --git a/util/uri.c b/util/uri.c > index 8624a7a..8bdef84 100644 > --- a/util/uri.c > +++ b/util/uri.c > @@ -52,6 +52,7 @@ > */ > > #include "qemu/osdep.h" > +#include "qemu/cutils.h" > > #include "qemu/uri.h" > > @@ -2266,10 +2267,7 @@ struct QueryParams *query_params_parse(const char *query) > /* Find the next separator, or end of the string. */ > end = strchr(query, '&'); > if (!end) { > - end = strchr(query, ';'); > - } > - if (!end) { > - end = query + strlen(query); > + end = qemu_strchrnul(query, ';'); > } > > /* Find the first '=' character between here and end. */
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