[Qemu-devel] [RFC v0 02/10] device_tree: return Error* from prop getters

[Peter A. G. Crosthwaite]

Rather than exit(1) on fail return an Error*. Clients can then handle errors as
they wish.

Signed-off-by: Peter A. G. Crosthwaite <peter.crosthwa...@petalogix.com>
---
 device_tree.c |   25 ++++++++++++++++++-------
 device_tree.h |    9 +++++++--
 hw/arm_boot.c |    8 ++++++--
 3 files changed, 31 insertions(+), 11 deletions(-)

diff --git a/device_tree.c b/device_tree.c
index 92a383e..3792085 100644
--- a/device_tree.c
+++ b/device_tree.c
@@ -179,7 +179,8 @@ int qemu_devtree_setprop_string(void *fdt, const char 
*node_path,
 }
 
 const void *qemu_devtree_getprop(void *fdt, const char *node_path,
-                                 const char *property, int *lenp)
+                                 const char *property, int *lenp,
+                                 Error **errp)
 {
     int len;
     const void *r;
@@ -190,20 +191,30 @@ const void *qemu_devtree_getprop(void *fdt, const char 
*node_path,
     if (!r) {
         fprintf(stderr, "%s: Couldn't get %s/%s: %s\n", __func__,
                 node_path, property, fdt_strerror(*lenp));
-        exit(1);
+        /* FIXME: Be smarter */
+        error_set(errp, QERR_UNDEFINED_ERROR);
+        return NULL;
     }
     return r;
 }
 
 uint32_t qemu_devtree_getprop_cell(void *fdt, const char *node_path,
-                                   const char *property, int offset)
+                                   const char *property, int offset,
+                                   Error **errp)
 {
     int len;
-    const uint32_t *p = qemu_devtree_getprop(fdt, node_path, property, &len);
+    const uint32_t *p = qemu_devtree_getprop(fdt, node_path, property, &len,
+                                                                        errp);
+    if (errp && *errp) {
+        return 0;
+    }
     if (len < (offset+1)*4) {
-        fprintf(stderr, "%s: %s/%s not long enough to hold %d properties\n",
-                __func__, node_path, property, offset+1);
-        exit(1);
+        fprintf(stderr, "%s: %s/%s not long enough to hold %d properties "
+                "(length = %d)\n", __func__, node_path, property,
+                offset+1, len);
+        /* FIXME: Be smarter */
+        error_set(errp, QERR_UNDEFINED_ERROR);
+        return 0;
     }
     return be32_to_cpu(p[offset]);
 }
diff --git a/device_tree.h b/device_tree.h
index 759e142..b707085 100644
--- a/device_tree.h
+++ b/device_tree.h
@@ -14,6 +14,9 @@
 #ifndef __DEVICE_TREE_H__
 #define __DEVICE_TREE_H__
 
+#include "qemu-common.h"
+#include "qerror.h"
+
 void *create_device_tree(int *sizep);
 void *load_device_tree(const char *filename_path, int *sizep);
 
@@ -29,9 +32,11 @@ int qemu_devtree_setprop_phandle(void *fdt, const char 
*node_path,
                                  const char *property,
                                  const char *target_node_path);
 const void *qemu_devtree_getprop(void *fdt, const char *node_path,
-                                 const char *property, int *lenp);
+                                 const char *property, int *lenp,
+                                 Error **errp);
 uint32_t qemu_devtree_getprop_cell(void *fdt, const char *node_path,
-                                   const char *property, int offset);
+                                   const char *property, int offset,
+                                   Error **errp);
 uint32_t qemu_devtree_get_phandle(void *fdt, const char *path);
 uint32_t qemu_devtree_alloc_phandle(void *fdt);
 int qemu_devtree_nop_node(void *fdt, const char *node_path);
diff --git a/hw/arm_boot.c b/hw/arm_boot.c
index 051aee6..45a7455 100644
--- a/hw/arm_boot.c
+++ b/hw/arm_boot.c
@@ -221,6 +221,8 @@ static int load_dtb(target_phys_addr_t addr, const struct 
arm_boot_info *binfo)
     void *fdt = NULL;
     char *filename;
     int size, rc;
+    Error *errp = NULL;
+
     uint32_t acells, scells, hival;
 
     filename = qemu_find_file(QEMU_FILE_TYPE_BIOS, binfo->dtb_filename);
@@ -237,8 +239,10 @@ static int load_dtb(target_phys_addr_t addr, const struct 
arm_boot_info *binfo)
     }
     g_free(filename);
 
-    acells = qemu_devtree_getprop_cell(fdt, "/", "#address-cells", 0);
-    scells = qemu_devtree_getprop_cell(fdt, "/", "#size-cells", 0);
+    acells = qemu_devtree_getprop_cell(fdt, "/", "#address-cells", 0, &errp);
+    scells = qemu_devtree_getprop_cell(fdt, "/", "#size-cells", 0, &errp);
+    assert_no_error(errp);
+
     if (acells == 0 || scells == 0) {
         fprintf(stderr, "dtb file invalid (#address-cells or #size-cells 
0)\n");
         return -1;
-- 
1.7.0.4