From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:57504) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1aIq69-0008Dm-DQ for qemu-devel@nongnu.org; Mon, 11 Jan 2016 22:58:22 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1aIq65-0001UH-9u for qemu-devel@nongnu.org; Mon, 11 Jan 2016 22:58:21 -0500 From: Peter Crosthwaite Date: Mon, 11 Jan 2016 19:58:12 -0800 Message-ID: <20160112035812.GE3308@pcrost-box> References: <1452245525-3886-1-git-send-email-eric.auger@linaro.org> <1452245525-3886-5-git-send-email-eric.auger@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1452245525-3886-5-git-send-email-eric.auger@linaro.org> Subject: Re: [Qemu-devel] [PATCH v4 4/8] device_tree: qemu_fdt_getprop converted to use the error API List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Eric Auger Cc: b.reynal@virtualopensystems.com, peter.maydell@linaro.org, thuth@redhat.com, eric.auger@st.com, patches@linaro.org, crosthwaitepeter@gmail.com, qemu-devel@nongnu.org, alex.williamson@redhat.com, qemu-arm@nongnu.org, suravee.suthikulpanit@amd.com, pbonzini@redhat.com, thomas.lendacky@amd.com, alex.bennee@linaro.org, christoffer.dall@linaro.org, david@gibson.dropbear.id.au On Fri, Jan 08, 2016 at 09:32:01AM +0000, Eric Auger wrote: > Current qemu_fdt_getprop exits if the property is not found. It is > sometimes needed to read an optional property, in which case we do > not wish to exit but simply returns a null value. > > This patch converts qemu_fdt_getprop to accept an Error **, and existing > users are converted to pass &error_fatal. This preserves the existing > behaviour. Then to use the API with your optional semantic a null > parameter can be conveyed. > > Signed-off-by: Eric Auger Reviewed-by: Peter Crosthwaite > > --- > > v1 -> v2: > - add a doc comment in the header file > > RFC -> v1: > - get rid of qemu_fdt_getprop_optional and implement Peter's suggestion > that consists in using the error API > > Signed-off-by: Eric Auger > --- > device_tree.c | 11 ++++++----- > include/sysemu/device_tree.h | 15 ++++++++++++++- > 2 files changed, 20 insertions(+), 6 deletions(-) > > diff --git a/device_tree.c b/device_tree.c > index 8441e01..6ecc9da 100644 > --- a/device_tree.c > +++ b/device_tree.c > @@ -321,18 +321,18 @@ int qemu_fdt_setprop_string(void *fdt, const char *node_path, > } > > const void *qemu_fdt_getprop(void *fdt, const char *node_path, > - const char *property, int *lenp) > + const char *property, int *lenp, Error **errp) > { > int len; > const void *r; > + > if (!lenp) { > lenp = &len; > } > r = fdt_getprop(fdt, findnode_nofail(fdt, node_path), property, lenp); > if (!r) { > - error_report("%s: Couldn't get %s/%s: %s", __func__, > - node_path, property, fdt_strerror(*lenp)); > - exit(1); > + error_setg(errp, "%s: Couldn't get %s/%s: %s", __func__, > + node_path, property, fdt_strerror(*lenp)); > } > return r; > } > @@ -341,7 +341,8 @@ uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path, > const char *property) > { > int len; > - const uint32_t *p = qemu_fdt_getprop(fdt, node_path, property, &len); > + const uint32_t *p = qemu_fdt_getprop(fdt, node_path, property, &len, > + &error_fatal); > if (len != 4) { > error_report("%s: %s/%s not 4 bytes long (not a cell?)", > __func__, node_path, property); > diff --git a/include/sysemu/device_tree.h b/include/sysemu/device_tree.h > index 269cb1c..4d7cbb9 100644 > --- a/include/sysemu/device_tree.h > +++ b/include/sysemu/device_tree.h > @@ -45,8 +45,21 @@ int qemu_fdt_setprop_string(void *fdt, const char *node_path, > int qemu_fdt_setprop_phandle(void *fdt, const char *node_path, > const char *property, > const char *target_node_path); > +/** > + * qemu_fdt_getprop: retrieve the value of a given property > + * @fdt: pointer to the device tree blob > + * @node_path: node path > + * @property: name of the property to find > + * @lenp: fdt error if any or length of the property on success > + * @errp: handle to an error object > + * > + * returns a pointer to the property on success and NULL on failure > + * in case errp is set to &error_fatal, the function auto-asserts > + * on error (legacy behavior) > + */ > const void *qemu_fdt_getprop(void *fdt, const char *node_path, > - const char *property, int *lenp); > + const char *property, int *lenp, > + Error **errp); > uint32_t qemu_fdt_getprop_cell(void *fdt, const char *node_path, > const char *property); > uint32_t qemu_fdt_get_phandle(void *fdt, const char *path); > -- > 1.9.1 >