[Qemu-devel] [PATCH] qapi-types: add C99 index names to arrays

[Qemu-devel] [PATCH] qapi-types: add C99 index names to arrays

[Michael S. Tsirkin]

It's not easy to figure out how monitor translates
strings: most QEMU code deals with translated indexes,
these are translated using _lookup arrays,
so you need to find the array name, and find the
appropriate offset.

This patch adds C99 indexes to lookup arrays, which makes it possible to
find the correct key using simple grep, and see that the matching is
correct at a glance.

Example:

Before:

const char *MigrationCapability_lookup[] = {
    "xbzrle",
    "rdma-pin-all",
    "auto-converge",
    "zero-blocks",
    NULL,
};

After:

const char *MigrationCapability_lookup[] = {
    [MIGRATION_CAPABILITY_XBZRLE] = "xbzrle",
    [MIGRATION_CAPABILITY_RDMA_PIN_ALL] = "rdma-pin-all",
    [MIGRATION_CAPABILITY_AUTO_CONVERGE] = "auto-converge",
    [MIGRATION_CAPABILITY_ZERO_BLOCKS] = "zero-blocks",
    [MIGRATION_CAPABILITY_MAX] = NULL,
};

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
---
 scripts/qapi-types.py | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)

diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
index 1eb272d..db87218 100644
--- a/scripts/qapi-types.py
+++ b/scripts/qapi-types.py
@@ -123,16 +123,19 @@ const char *%(name)s_lookup[] = {
                          name=name)
     i = 0
     for value in values:
+        index = generate_enum_full_value(name, value)
         ret += mcgen('''
-    "%(value)s",
+    [%(index)s] = "%(value)s",
 ''',
-                     value=value)
+                     index = index, value = value)
 
+    max_index = generate_enum_full_value(name, 'MAX')
     ret += mcgen('''
-    NULL,
+    [%(max_index)s] = NULL,
 };
 
-''')
+''',
+        max_index=max_index)
     return ret
 
 def generate_enum(name, values):
-- 
MST

Re: [Qemu-devel] [PATCH] qapi-types: add C99 index names to arrays

[Eric Blake]

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On 02/19/2015 03:13 AM, Michael S. Tsirkin wrote:
> It's not easy to figure out how monitor translates
> strings: most QEMU code deals with translated indexes,
> these are translated using _lookup arrays,
> so you need to find the array name, and find the
> appropriate offset.
> 
> This patch adds C99 indexes to lookup arrays, which makes it possible to
> find the correct key using simple grep, and see that the matching is
> correct at a glance.
> 
> Example:
> 
> Before:
> 
> const char *MigrationCapability_lookup[] = {
>     "xbzrle",
>     "rdma-pin-all",
>     "auto-converge",
>     "zero-blocks",
>     NULL,
> };
> 
> After:
> 
> const char *MigrationCapability_lookup[] = {
>     [MIGRATION_CAPABILITY_XBZRLE] = "xbzrle",
>     [MIGRATION_CAPABILITY_RDMA_PIN_ALL] = "rdma-pin-all",
>     [MIGRATION_CAPABILITY_AUTO_CONVERGE] = "auto-converge",
>     [MIGRATION_CAPABILITY_ZERO_BLOCKS] = "zero-blocks",
>     [MIGRATION_CAPABILITY_MAX] = NULL,
> };

I like it :)

> 
> Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
> ---
>  scripts/qapi-types.py | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)

Reviewed-by: Eric Blake <eblake@redhat.com>

-- 
Eric Blake   eblake redhat com    +1-919-301-3266
Libvirt virtualization library http://libvirt.org


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