[libvirt] [PATCH] random: link with -lm when needed
Use of ldexp() requires -lm on some platforms; use gnulib to determine
this for our makefile. Also, optimize virRandomInt() for the case
of a power-of-two limit (actually rather common, given that Daniel
has a pending patch to replace virRandomBis(10) with code that will
default to virRandomInt(1024) on default SELinux settings).
* .gnulib: Update to latest, for ldexp.
* bootstrap.conf (gnulib_modules): Import ldexp.
* src/Makefile.am (libvirt_util_la_CFLAGS): Link with -lm when
needed.
* src/util/virrandom.c (virRandomInt): Optimize powers of 2.
---
Gnulib changes:
* .gnulib dbd9144...271dd74 (37):
ldexp: relax license
update from texinfo
gnulib-tool: Fix persistence of --witness-c-macro option.
count-leading-zeros: use a lookup table on non-gcc compilers
count-leading-zeros: new module
maintainer-makefile: Fix syntax error with dash.
extern-inline: also ignore -Wmissing-declarations
autoupdate
maint.mk: sc_prohibit_magic_number_exit: avoid new false positives
gnumakefile: better interaction with Automake-NG
base64: Use extern C scope in header file, for C++.
stat-time, timespec, u64: support naive out-of-dir builds
Fix typo: 'linline' -> 'inline' (thanks to Eric Blake).
Keep the extern-inline macros closer together.
Fix indenting.
utimens: use extern-inline
u64: use extern-inline
timespec: use extern-inline
stat-time: use extern-inline
extern-inline: new module
maint.mk: a "release-commit" wrapper to do-release-commit-and-tag
autoupdate
autoupdate
maint.mk: use silent-rules support from Automake
maint.mk: provide a web-manual-update target
README-release: shorten the circuit to post a news
gnu-web-doc-update: fix --help
passfd: fix comment on recvfd
maint.mk: avoid a sub-shell
maint.mk: absolute VPATH issue
update from texinfo
gitlog-to-changelog: fix previous change
gitlog-to-changelog: don't expect .git to be in $srcdir
maint.mk: absolute VPATH build fix
clean-temp: Fix memory leak.
maint: fix grammar in a ChangeLog entry
maint.mk: new rule: refresh-gnulib-patches
.gnulib | 2 +-
bootstrap.conf | 1 +
src/Makefile.am | 2 +-
src/util/virrandom.c | 4 ++++
4 files changed, 7 insertions(+), 2 deletions(-)
diff --git a/.gnulib b/.gnulib
index dbd9144..271dd74 160000
--- a/.gnulib
+++ b/.gnulib
@@ -1 +1 @@
-Subproject commit dbd914496c99c52220e5f5ba4121d6cb55fb3beb
+Subproject commit 271dd74fdf54ec2a03e73a5173b0b5697f6088f1
diff --git a/bootstrap.conf b/bootstrap.conf
index a4e1c2f..a6cfe24 100644
--- a/bootstrap.conf
+++ b/bootstrap.conf
@@ -61,6 +61,7 @@ intprops
ioctl
isatty
largefile
+ldexp
listen
localeconv
maintainer-makefile
diff --git a/src/Makefile.am b/src/Makefile.am
index e94f977..cec4789 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -654,7 +654,7 @@ libvirt_util_la_SOURCES = \
$(UTIL_SOURCES)
libvirt_util_la_CFLAGS = $(CAPNG_CFLAGS) $(YAJL_CFLAGS) $(LIBNL_CFLAGS) \
$(AM_CFLAGS) $(AUDIT_CFLAGS) $(DEVMAPPER_CFLAGS) \
- $(DBUS_CFLAGS)
+ $(DBUS_CFLAGS) $(LDEXP_LIBM)
libvirt_util_la_LIBADD = $(CAPNG_LIBS) $(YAJL_LIBS) $(LIBNL_LIBS) \
$(THREAD_LIBS) $(AUDIT_LIBS) $(DEVMAPPER_LIBS) \
$(RT_LIBS) $(DBUS_LIBS) $(MSCOM_LIBS) $(LIBXML_LIBS)
diff --git a/src/util/virrandom.c b/src/util/virrandom.c
index 363fcab..8870865 100644
--- a/src/util/virrandom.c
+++ b/src/util/virrandom.c
@@ -24,6 +24,7 @@
#include <stdlib.h>
#include <inttypes.h>
#include <math.h>
+#include <strings.h>
#include "virrandom.h"
#include "threads.h"
@@ -135,6 +136,9 @@ double virRandom(void)
*/
uint32_t virRandomInt(uint32_t max)
{
+ if ((max & (max - 1)) == 0)
+ return virRandomBits(ffs(max));
+
double val = virRandom();
return val * max;
}
--
1.7.11.2