[v4,2/5] qapi: auto generate enum value strings

Automatically generate enum value strings that containing the acceptable values.
(Borrowed Daniel's code.)

Signed-off-by: Lin Ma <lma@suse.com>
---
 scripts/qapi-types.py | 2 ++
 scripts/qapi.py       | 9 +++++++++
 2 files changed, 11 insertions(+)

Lin Ma <lma@suse.com> writes:

> Automatically generate enum value strings that containing the acceptable values.
> (Borrowed Daniel's code.)
>
> Signed-off-by: Lin Ma <lma@suse.com>
> ---
>  scripts/qapi-types.py | 2 ++
>  scripts/qapi.py       | 9 +++++++++
>  2 files changed, 11 insertions(+)
>
> diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
> index dabc42e..0446839 100644
> --- a/scripts/qapi-types.py
> +++ b/scripts/qapi-types.py
> @@ -202,9 +202,11 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
>              self._btin += gen_enum(name, values, prefix)
>              if do_builtins:
>                  self.defn += gen_enum_lookup(name, values, prefix)
> +                self._btin += gen_enum_value_str(name, values)
>          else:
>              self._fwdecl += gen_enum(name, values, prefix)
>              self.defn += gen_enum_lookup(name, values, prefix)
> +            self._fwdecl += gen_enum_value_str(name, values)
>  
>      def visit_array_type(self, name, info, element_type):
>          if isinstance(element_type, QAPISchemaBuiltinType):
> diff --git a/scripts/qapi.py b/scripts/qapi.py
> index 21bc32f..d11c414 100644
> --- a/scripts/qapi.py
> +++ b/scripts/qapi.py
> @@ -1649,6 +1649,15 @@ const char *const %(c_name)s_lookup[] = {
>      return ret
>  
>  
> +def gen_enum_value_str(name, values):
> +    return mcgen('''
> +
> +#define %(c_name)s_value_str "%(value_str)s"
> +''',
> +                c_name=c_name(name),
> +                value_str=", ".join(["'%s'" % c for c in values]))
> +
> +
>  def gen_enum(name, values, prefix=None):
>      # append automatically generated _MAX value
>      enum_values = values + ['_MAX']

This function is generating a macro definition, not a string.  We could
call it gen_enum_values_define().  But I'd simply fold it into
gen_enum().

Adds another 9KiB to qapi-types.h, which is included widely.  Instead of
defining these macros, we could also iterate over FOO_lookup[] at
run-time.  But let's first review how the macro is used.

>>> Markus Armbruster <armbru@redhat.com> 2016/11/4 星期五 上午 3:17 >>>
>Lin Ma <lma@suse.com> writes:
>
>> Automatically generate enum value strings that containing the acceptable values.
>> (Borrowed Daniel's code.)
>>
>> Signed-off-by: Lin Ma <lma@suse.com>
>> ---
>>  scripts/qapi-types.py | 2 ++
>>  scripts/qapi.py       | 9 +++++++++
>>  2 files changed, 11 insertions(+)
>>
>> diff --git a/scripts/qapi-types.py b/scripts/qapi-types.py
>> index dabc42e..0446839 100644
>> --- a/scripts/qapi-types.py
>> +++ b/scripts/qapi-types.py
>> @@ -202,9 +202,11 @@ class QAPISchemaGenTypeVisitor(QAPISchemaVisitor):
>>			  self._btin += gen_enum(name, values, prefix)
>>			  if do_builtins:
>>				  self.defn += gen_enum_lookup(name, values, prefix)
>> +			    self._btin += gen_enum_value_str(name, values)
>>		  else:
>>			  self._fwdecl += gen_enum(name, values, prefix)
>>			  self.defn += gen_enum_lookup(name, values, prefix)
>> +		    self._fwdecl += gen_enum_value_str(name, values)
>>  
>>	  def visit_array_type(self, name, info, element_type):
>>		  if isinstance(element_type, QAPISchemaBuiltinType):
>> diff --git a/scripts/qapi.py b/scripts/qapi.py
>> index 21bc32f..d11c414 100644
>> --- a/scripts/qapi.py
>> +++ b/scripts/qapi.py
>> @@ -1649,6 +1649,15 @@ const char *const %(c_name)s_lookup[] = {
>>	  return ret
>>  
>>  
>> +def gen_enum_value_str(name, values):
>> +    return mcgen('''
>> +
>> +#define %(c_name)s_value_str "%(value_str)s"
>> +''',
>> +			    c_name=c_name(name),
>> +			    value_str=", ".join(["'%s'" % c for c in values]))
>> +
>> +
>>  def gen_enum(name, values, prefix=None):
>>	  # append automatically generated _MAX value
>>	  enum_values = values + ['_MAX']
>
>This function is generating a macro definition, not a string.  We could
>call it gen_enum_values_define().  But I'd simply fold it into
>gen_enum().
>
>Adds another 9KiB to qapi-types.h, which is included widely.  Instead of
>defining these macros, we could also iterate over FOO_lookup[] at
>run-time.  But let's first review how the macro is used.
Sorry, I'm not familiar with writing qemu test code. I didn't understand it.
What's the meaning of 'Adds another 9KiB to qapi-types.h'? What is '9KiB'?
 
Thanks,
Lin