[PATCH 3/7] Add ld version-script

Peter Hutterer peter.hutterer at who-t.net
Wed Aug 21 22:42:49 PDT 2013


On Sat, Aug 17, 2013 at 01:58:15PM +0200, David Herrmann wrote:
> Explicit symbol versioning allows us to provide multiple versions of
> incompatible API changes. It is a very common practice in GNU world and
> avoids the problems occuring if distributions try to ship multiple version
> of a single DSO.
> 
> We currently don't have any incompatibilities, but we need to start
> versioning right from the beginning to allow for smooth transitions later.
> 
> Background information available at:
>   http://people.redhat.com/drepper/dsohowto.pdf
> 
> To see the symbol-versions, use objdump:
>   objdump -T libevdev/.libs/libevdev.so.1.0.0
> This can also be used to verify that all 67 symbols are correctly
> exported (typos in linker-scripts are silently ignored by ld).

I wonder if we can hook this up with make check somehow to make sure we
don't push an API/ABI change without the matching updates to the symbol
versioning script..

> Note that we cannot mix linker-scripts with -export-* commands so we
> explicitly have to mark all symbols as visibility=public via EXPORT.
> 
> Signed-off-by: David Herrmann <dh.herrmann at gmail.com>
> ---
>  libevdev/Makefile.am    |  9 +++--
>  libevdev/libevdev-int.h |  1 +
>  libevdev/libevdev.c     | 92 ++++++++++++++++++++++++-----------------------
>  libevdev/libevdev.sym   | 95 +++++++++++++++++++++++++++++++++++++++++++++++++
>  4 files changed, 151 insertions(+), 46 deletions(-)
>  create mode 100644 libevdev/libevdev.sym
> 
> diff --git a/libevdev/Makefile.am b/libevdev/Makefile.am
> index e71b980..bd8e4fe 100644
> --- a/libevdev/Makefile.am
> +++ b/libevdev/Makefile.am
> @@ -8,7 +8,12 @@ libevdev_la_SOURCES = \
>                     libevdev-util.h \
>                     libevdev.c
>  
> -libevdev_la_LDFLAGS = -version-info $(LIBEVDEV_LT_VERSION) -export-symbols-regex '^libevdev_' $(GCOV_LDFLAGS)
> +libevdev_la_LDFLAGS = \
> +	-version-info $(LIBEVDEV_LT_VERSION) \
> +	-Wl,--version-script="$(srcdir)/libevdev.sym" \
> +	$(GCOV_LDFLAGS)
> +
> +EXTRA_libevdev_la_DEPENDENCIES = $(srcdir)/libevdev.sym
>  
>  libevdevincludedir = $(includedir)/libevdev-1.0/libevdev
>  libevdevinclude_HEADERS = libevdev.h
> @@ -16,7 +21,7 @@ libevdevinclude_HEADERS = libevdev.h
>  event-names.h: Makefile make-event-names.py
>  	$(PYTHON2) $(srcdir)/make-event-names.py --output=c > $@
>  
> -EXTRA_DIST = make-event-names.py
> +EXTRA_DIST = make-event-names.py libevdev.sym
>  CLEANFILES = event-names.h
>  BUILT_SOURCES = event-names.h
>  
> diff --git a/libevdev/libevdev-int.h b/libevdev/libevdev-int.h
> index a36be62..7b6df65 100644
> --- a/libevdev/libevdev-int.h
> +++ b/libevdev/libevdev-int.h
> @@ -37,6 +37,7 @@
>  #define ABS_MT_MIN ABS_MT_SLOT
>  #define ABS_MT_MAX ABS_MT_TOOL_Y
>  #define ABS_MT_CNT (ABS_MT_MAX - ABS_MT_MIN + 1)
> +#define EXPORT __attribute__((visibility("default")))

libevdev.h is included in other files, so I'd rather have EXPORT namespaced
to avoid oddness.

Cheers,
   Peter

>  
>  #undef min
>  #undef max
> diff --git a/libevdev/libevdev.c b/libevdev/libevdev.c
> index 0d315ec..9f81177 100644
> --- a/libevdev/libevdev.c
> +++ b/libevdev/libevdev.c
> @@ -64,7 +64,7 @@ libevdev_noop_log_func(const char *format, va_list args)
>  {
>  }
>  
> -struct libevdev*
> +EXPORT struct libevdev*
>  libevdev_new(void)
>  {
>  	struct libevdev *dev;
> @@ -82,7 +82,7 @@ libevdev_new(void)
>  	return dev;
>  }
>  
> -int
> +EXPORT int
>  libevdev_new_from_fd(int fd, struct libevdev **dev)
>  {
>  	struct libevdev *d;
> @@ -100,7 +100,7 @@ libevdev_new_from_fd(int fd, struct libevdev **dev)
>  	return rc;
>  }
>  
> -void
> +EXPORT void
>  libevdev_free(struct libevdev *dev)
>  {
>  	if (!dev)
> @@ -113,7 +113,7 @@ libevdev_free(struct libevdev *dev)
>  	free(dev);
>  }
>  
> -void
> +EXPORT void
>  libevdev_set_log_handler(struct libevdev *dev, libevdev_log_func_t logfunc)
>  {
>  	if (dev == NULL)
> @@ -122,7 +122,7 @@ libevdev_set_log_handler(struct libevdev *dev, libevdev_log_func_t logfunc)
>  	dev->log = logfunc ? logfunc : libevdev_noop_log_func;
>  }
>  
> -int
> +EXPORT int
>  libevdev_change_fd(struct libevdev *dev, int fd)
>  {
>  	if (dev->fd == -1)
> @@ -131,7 +131,7 @@ libevdev_change_fd(struct libevdev *dev, int fd)
>  	return 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_set_fd(struct libevdev* dev, int fd)
>  {
>  	int rc;
> @@ -275,7 +275,7 @@ out:
>  	return rc ? -errno : 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_get_fd(const struct libevdev* dev)
>  {
>  	return dev->fd;
> @@ -545,7 +545,8 @@ read_more_events(struct libevdev *dev)
>  	return 0;
>  }
>  
> -int libevdev_next_event(struct libevdev *dev, unsigned int flags, struct input_event *ev)
> +EXPORT int
> +libevdev_next_event(struct libevdev *dev, unsigned int flags, struct input_event *ev)
>  {
>  	int rc = 0;
>  
> @@ -629,7 +630,8 @@ out:
>  	return rc;
>  }
>  
> -int libevdev_has_event_pending(struct libevdev *dev)
> +EXPORT int
> +libevdev_has_event_pending(struct libevdev *dev)
>  {
>  	struct pollfd fds = { dev->fd, POLLIN, 0 };
>  	int rc;
> @@ -644,26 +646,26 @@ int libevdev_has_event_pending(struct libevdev *dev)
>  	return (rc >= 0) ? rc : -errno;
>  }
>  
> -const char *
> +EXPORT const char *
>  libevdev_get_name(const struct libevdev *dev)
>  {
>  	return dev->name ? dev->name : "";
>  }
>  
> -const char *
> +EXPORT const char *
>  libevdev_get_phys(const struct libevdev *dev)
>  {
>  	return dev->phys;
>  }
>  
> -const char *
> +EXPORT const char *
>  libevdev_get_uniq(const struct libevdev *dev)
>  {
>  	return dev->uniq;
>  }
>  
>  #define STRING_SETTER(field) \
> -void libevdev_set_##field(struct libevdev *dev, const char *field) \
> +EXPORT void libevdev_set_##field(struct libevdev *dev, const char *field) \
>  { \
>  	if (field == NULL) \
>  		return; \
> @@ -677,7 +679,7 @@ STRING_SETTER(uniq);
>  
>  
>  #define PRODUCT_GETTER(name, field) \
> -int libevdev_get_##name(const struct libevdev *dev) \
> +EXPORT int libevdev_get_##name(const struct libevdev *dev) \
>  { \
>  	return dev->ids.field; \
>  }
> @@ -693,7 +695,7 @@ PRODUCT_GETTER(id_bustype, bustype);
>  PRODUCT_GETTER(id_version, version);
>  
>  #define PRODUCT_SETTER(field) \
> -void libevdev_set_id_##field(struct libevdev *dev, int field) \
> +EXPORT void libevdev_set_id_##field(struct libevdev *dev, int field) \
>  { \
>  	dev->ids.field = field;\
>  }
> @@ -703,18 +705,19 @@ PRODUCT_SETTER(vendor);
>  PRODUCT_SETTER(bustype);
>  PRODUCT_SETTER(version);
>  
> -int libevdev_get_driver_version(const struct libevdev *dev)
> +EXPORT int
> +libevdev_get_driver_version(const struct libevdev *dev)
>  {
>  	return dev->driver_version;
>  }
>  
> -int
> +EXPORT int
>  libevdev_has_property(const struct libevdev *dev, unsigned int prop)
>  {
>  	return (prop <= INPUT_PROP_MAX) && bit_is_set(dev->props, prop);
>  }
>  
> -int
> +EXPORT int
>  libevdev_enable_property(struct libevdev *dev, unsigned int prop)
>  {
>  	if (prop > INPUT_PROP_MAX)
> @@ -724,13 +727,13 @@ libevdev_enable_property(struct libevdev *dev, unsigned int prop)
>  	return 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_has_event_type(const struct libevdev *dev, unsigned int type)
>  {
>  	return (type <= EV_MAX) && bit_is_set(dev->bits, type);
>  }
>  
> -int
> +EXPORT int
>  libevdev_has_event_code(const struct libevdev *dev, unsigned int type, unsigned int code)
>  {
>  	const unsigned long *mask;
> @@ -750,7 +753,7 @@ libevdev_has_event_code(const struct libevdev *dev, unsigned int type, unsigned
>  	return bit_is_set(mask, code);
>  }
>  
> -int
> +EXPORT int
>  libevdev_get_event_value(const struct libevdev *dev, unsigned int type, unsigned int code)
>  {
>  	int value;
> @@ -769,7 +772,7 @@ libevdev_get_event_value(const struct libevdev *dev, unsigned int type, unsigned
>  	return value;
>  }
>  
> -int
> +EXPORT int
>  libevdev_fetch_event_value(const struct libevdev *dev, unsigned int type, unsigned int code, int *value)
>  {
>  	if (libevdev_has_event_type(dev, type) &&
> @@ -780,7 +783,7 @@ libevdev_fetch_event_value(const struct libevdev *dev, unsigned int type, unsign
>  		return 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_get_slot_value(const struct libevdev *dev, unsigned int slot, unsigned int code)
>  {
>  	if (!libevdev_has_event_type(dev, EV_ABS) || !libevdev_has_event_code(dev, EV_ABS, code))
> @@ -795,7 +798,7 @@ libevdev_get_slot_value(const struct libevdev *dev, unsigned int slot, unsigned
>  	return dev->mt_slot_vals[slot][code - ABS_MT_MIN];
>  }
>  
> -int
> +EXPORT int
>  libevdev_fetch_slot_value(const struct libevdev *dev, unsigned int slot, unsigned int code, int *value)
>  {
>  	if (libevdev_has_event_type(dev, EV_ABS) &&
> @@ -807,19 +810,19 @@ libevdev_fetch_slot_value(const struct libevdev *dev, unsigned int slot, unsigne
>  		return 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_get_num_slots(const struct libevdev *dev)
>  {
>  	return dev->num_slots;
>  }
>  
> -int
> +EXPORT int
>  libevdev_get_current_slot(const struct libevdev *dev)
>  {
>  	return dev->current_slot;
>  }
>  
> -const struct input_absinfo*
> +EXPORT const struct input_absinfo*
>  libevdev_get_abs_info(const struct libevdev *dev, unsigned int code)
>  {
>  	if (!libevdev_has_event_type(dev, EV_ABS) ||
> @@ -830,7 +833,7 @@ libevdev_get_abs_info(const struct libevdev *dev, unsigned int code)
>  }
>  
>  #define ABS_GETTER(name, field) \
> -int libevdev_get_abs_##name(const struct libevdev *dev, unsigned int code) \
> +EXPORT int libevdev_get_abs_##name(const struct libevdev *dev, unsigned int code) \
>  { \
>  	const struct input_absinfo *absinfo = libevdev_get_abs_info(dev, code); \
>  	return absinfo ? absinfo->field : 0; \
> @@ -845,7 +848,7 @@ ABS_GETTER(flat, flat)
>  ABS_GETTER(resolution, resolution)
>  
>  #define ABS_SETTER(field) \
> -void libevdev_set_abs_##field(struct libevdev *dev, unsigned int code, int val) \
> +EXPORT void libevdev_set_abs_##field(struct libevdev *dev, unsigned int code, int val) \
>  { \
>  	if (!libevdev_has_event_code(dev, EV_ABS, code)) \
>  		return; \
> @@ -858,7 +861,8 @@ ABS_SETTER(fuzz)
>  ABS_SETTER(flat)
>  ABS_SETTER(resolution)
>  
> -void libevdev_set_abs_info(struct libevdev *dev, unsigned int code, const struct input_absinfo *abs)
> +EXPORT void
> +libevdev_set_abs_info(struct libevdev *dev, unsigned int code, const struct input_absinfo *abs)
>  {
>  	if (!libevdev_has_event_code(dev, EV_ABS, code))
>  		return;
> @@ -866,7 +870,7 @@ void libevdev_set_abs_info(struct libevdev *dev, unsigned int code, const struct
>  	dev->abs_info[code] = *abs;
>  }
>  
> -int
> +EXPORT int
>  libevdev_enable_event_type(struct libevdev *dev, unsigned int type)
>  {
>  	if (type > EV_MAX)
> @@ -885,7 +889,7 @@ libevdev_enable_event_type(struct libevdev *dev, unsigned int type)
>  	return 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_disable_event_type(struct libevdev *dev, unsigned int type)
>  {
>  	if (type > EV_MAX || type == EV_SYN)
> @@ -896,7 +900,7 @@ libevdev_disable_event_type(struct libevdev *dev, unsigned int type)
>  	return 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_enable_event_code(struct libevdev *dev, unsigned int type,
>  			   unsigned int code, const void *data)
>  {
> @@ -938,7 +942,7 @@ libevdev_enable_event_code(struct libevdev *dev, unsigned int type,
>  	return 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_disable_event_code(struct libevdev *dev, unsigned int type, unsigned int code)
>  {
>  	unsigned int max;
> @@ -957,7 +961,7 @@ libevdev_disable_event_code(struct libevdev *dev, unsigned int type, unsigned in
>  	return 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_kernel_set_abs_value(struct libevdev *dev, unsigned int code, const struct input_absinfo *abs)
>  {
>  	int rc;
> @@ -974,7 +978,7 @@ libevdev_kernel_set_abs_value(struct libevdev *dev, unsigned int code, const str
>  	return rc;
>  }
>  
> -int
> +EXPORT int
>  libevdev_grab(struct libevdev *dev, int grab)
>  {
>  	int rc = 0;
> @@ -996,13 +1000,13 @@ libevdev_grab(struct libevdev *dev, int grab)
>  	return rc < 0 ? -errno : 0;
>  }
>  
> -int
> +EXPORT int
>  libevdev_is_event_type(const struct input_event *ev, unsigned int type)
>  {
>  	return type < EV_MAX && ev->type == type;
>  }
>  
> -int
> +EXPORT int
>  libevdev_is_event_code(const struct input_event *ev, unsigned int type, unsigned int code)
>  {
>  	return type < EV_MAX &&
> @@ -1011,7 +1015,7 @@ libevdev_is_event_code(const struct input_event *ev, unsigned int type, unsigned
>  		ev->code == code;
>  }
>  
> -const char*
> +EXPORT const char*
>  libevdev_get_event_type_name(unsigned int type)
>  {
>  	if (type > EV_MAX)
> @@ -1020,7 +1024,7 @@ libevdev_get_event_type_name(unsigned int type)
>  	return ev_map[type];
>  }
>  
> -const char*
> +EXPORT const char*
>  libevdev_get_event_code_name(unsigned int type, unsigned int code)
>  {
>  	if (type > EV_MAX)
> @@ -1033,13 +1037,13 @@ libevdev_get_event_code_name(unsigned int type, unsigned int code)
>  }
>  
>  /* DEPRECATED */
> -const char*
> +EXPORT const char*
>  libevdev_get_input_prop_name(unsigned int prop)
>  {
>  	return libevdev_get_property_name(prop);
>  }
>  
> -const char*
> +EXPORT const char*
>  libevdev_get_property_name(unsigned int prop)
>  {
>  	if (prop > INPUT_PROP_MAX)
> @@ -1048,7 +1052,7 @@ libevdev_get_property_name(unsigned int prop)
>  	return input_prop_map[prop];
>  }
>  
> -int
> +EXPORT int
>  libevdev_get_event_type_max(unsigned int type)
>  {
>  	if (type > EV_MAX)
> @@ -1057,7 +1061,7 @@ libevdev_get_event_type_max(unsigned int type)
>  	return ev_max[type];
>  }
>  
> -int
> +EXPORT int
>  libevdev_get_repeat(struct libevdev *dev, int *delay, int *period)
>  {
>  	if (!libevdev_has_event_type(dev, EV_REP))
> diff --git a/libevdev/libevdev.sym b/libevdev/libevdev.sym
> new file mode 100644
> index 0000000..4cf40bb
> --- /dev/null
> +++ b/libevdev/libevdev.sym
> @@ -0,0 +1,95 @@
> +/*
> + * Copyright (c) 2013 David Herrmann <dh.herrmann at gmail.com>
> + *
> + * Permission to use, copy, modify, distribute, and sell this software and its
> + * documentation for any purpose is hereby granted without fee, provided that
> + * the above copyright notice appear in all copies and that both that copyright
> + * notice and this permission notice appear in supporting documentation, and
> + * that the name of the copyright holders not be used in advertising or
> + * publicity pertaining to distribution of the software without specific,
> + * written prior permission.  The copyright holders make no representations
> + * about the suitability of this software for any purpose.  It is provided "as
> + * is" without express or implied warranty.
> + *
> + * THE COPYRIGHT HOLDERS DISCLAIM ALL WARRANTIES WITH REGARD TO THIS SOFTWARE,
> + * INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS, IN NO
> + * EVENT SHALL THE COPYRIGHT HOLDERS BE LIABLE FOR ANY SPECIAL, INDIRECT OR
> + * CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE,
> + * DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
> + * TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
> + * OF THIS SOFTWARE.
> + */
> +
> +LIBEVDEV_1 {
> +global:
> +	libevdev_new;
> +	libevdev_new_from_fd;
> +	libevdev_free;
> +	libevdev_set_log_handler;
> +	libevdev_grab;
> +	libevdev_set_fd;
> +	libevdev_change_fd;
> +	libevdev_get_fd;
> +	libevdev_next_event;
> +	libevdev_has_event_pending;
> +	libevdev_get_name;
> +	libevdev_set_name;
> +	libevdev_get_phys;
> +	libevdev_set_phys;
> +	libevdev_get_uniq;
> +	libevdev_set_uniq;
> +	libevdev_get_id_product;
> +	libevdev_set_id_product;
> +	libevdev_get_id_vendor;
> +	libevdev_set_id_vendor;
> +	libevdev_get_id_bustype;
> +	libevdev_set_id_bustype;
> +	libevdev_get_id_version;
> +	libevdev_set_id_version;
> +	libevdev_get_driver_version;
> +	libevdev_has_property;
> +	libevdev_enable_property;
> +	libevdev_has_event_type;
> +	libevdev_has_event_code;
> +	libevdev_get_abs_minimum;
> +	libevdev_get_abs_maximum;
> +	libevdev_get_abs_fuzz;
> +	libevdev_get_abs_flat;
> +	libevdev_get_abs_resolution;
> +	libevdev_get_abs_info;
> +	libevdev_get_event_value;
> +	libevdev_fetch_event_value;
> +	libevdev_get_slot_value;
> +	libevdev_fetch_slot_value;
> +	libevdev_get_num_slots;
> +	libevdev_get_current_slot;
> +	libevdev_set_abs_minimum;
> +	libevdev_set_abs_maximum;
> +	libevdev_set_abs_fuzz;
> +	libevdev_set_abs_flat;
> +	libevdev_set_abs_resolution;
> +	libevdev_set_abs_info;
> +	libevdev_enable_event_type;
> +	libevdev_disable_event_type;
> +	libevdev_enable_event_code;
> +	libevdev_disable_event_code;
> +	libevdev_kernel_set_abs_value;
> +	libevdev_is_event_type;
> +	libevdev_is_event_code;
> +	libevdev_get_event_type_name;
> +	libevdev_get_event_code_name;
> +	libevdev_get_property_name;
> +	libevdev_get_event_type_max;
> +	libevdev_get_repeat;
> +
> +	/* deprecated */
> +	libevdev_get_abs_min;
> +	libevdev_get_abs_max;
> +	libevdev_get_input_prop_name;
> +	libevdev_get_product_id;
> +	libevdev_get_vendor_id;
> +	libevdev_get_bustype;
> +	libevdev_get_version;
> +local:
> +	*;
> +};
> -- 
> 1.8.3.4
> 


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