Re: [PATCH 06/37] qapi: delint using flake8

2020-09-21 Thread John Snow

On 9/21/20 3:31 AM, Markus Armbruster wrote:

John Snow  writes:


On 9/18/20 6:33 AM, Markus Armbruster wrote:

John Snow  writes:

[...]



2. Writing a templating engine that doesn't break the Python
indentation flow by hoisting them into module constants and improving
the rendering logic.


Too vague for me to judge, happy to look at PoC patches.



Okay, some other day. Not important enough presently. It's just hard to 
stop brainstorming ideas as I learn about and touch different areas of code.


--js




Re: [PATCH 06/37] qapi: delint using flake8

2020-09-21 Thread Markus Armbruster
John Snow  writes:

> On 9/18/20 6:33 AM, Markus Armbruster wrote:
>> John Snow  writes:
[...]
>>> Embedded templates are always gonna look kinda nasty, I think, because
>>> you're trying to fight style guidelines in two languages
>>> simultaneously and it's never gonna quite work out exactly how you
>>> want without some pretty complex abstraction mechanisms that are well
>>> beyond the power we need right now.
>> The thought "screw this, pile the output through /usr/bin/indent"
>> has
>> crossed my mind more than once.
>> 
>
> Bigger fish to fry, but with other languages like rust looming, making
> the core generation facilities nicer might be ...nice. Not for this
> series.

Definitely not.

The way we generate C now is (close to) the stupidest way that could
possibly work.  Stupid is *good*, until it creates actual problems.

Any improvement will have to balance readability vs. hackability.

What we have now is often hard to read, but pretty easy to hack.  May
sound like a contradiction, but it's been my experience.

> Two approaches in general would make sense to me:
>
> 1. Building an AST for C instead of strings, and rendering the AST.

I fear the need to define an AST for C makes this uneconomical.

I've missed the ease of generating Lisp in Lisp many times.

> 2. Writing a templating engine that doesn't break the Python
> indentation flow by hoisting them into module constants and improving
> the rendering logic.

Too vague for me to judge, happy to look at PoC patches.




Re: [PATCH 06/37] qapi: delint using flake8

2020-09-18 Thread John Snow

On 9/18/20 6:33 AM, Markus Armbruster wrote:

John Snow  writes:


On 9/17/20 3:54 AM, Markus Armbruster wrote:

John Snow  writes:


On 9/16/20 8:12 AM, Markus Armbruster wrote:

John Snow  writes:


Petty style guide fixes and line length enforcement.  Not a big win, not
a big loss, but flake8 passes 100% on the qapi module, which gives us an
easy baseline to enforce hereafter.

Signed-off-by: John Snow 

[...]

diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index e1df0e341f..2e4b4de0fa 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -69,7 +69,8 @@ def gen_call(name, arg_type, boxed, ret_type):
def gen_marshal_output(ret_type):
return mcgen('''
-static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
QObject **ret_out, Error **errp)
+static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out,
+  Error **errp)

The continued parameter list may become misalignd in generated C.
E.g.
   static void qmp_marshal_output_BlockInfoList(BlockInfoList *ret_in, 
QObject **ret_out,
 Error **errp)
   {
   ...
   }
Do we care?



Yeah, I don't know. Do we?

I care, but I also care for automated style checks.


It actually seemed more annoying to try and get flake8 to make an
exception for these handful of examples.

Path of least resistance led me here, but I can try and appease both
systems if you'd prefer.

Up to now, I ran the style checkers manually, and this was just one
of
several complaints to ignore, so I left the code alone.
If it gets in the way of running them automatically, and messing up
the
generated code slightly is the easiest way to get it out of the way,
then I can accept the slight mess.



I changed this a little to put all the args on the next line, which is
slightly unusual but works okay.


I think it's slightly more unusual than the non-matching indentation
was.

Yet another way to skin this cat:

 static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
 QObject **ret_out, Error **errp)

Now the second line is not aligned with the left parenthesis both in the
Python source and in the generated C.



Your wish is my command!
(Except in the other replies where I am arguing with you.)


I think that's a fine middle ground, because the alternative (to me)
is to start using abstracted code generation tokens in a tree
structure, etc etc etc.

Embedded templates are always gonna look kinda nasty, I think, because
you're trying to fight style guidelines in two languages
simultaneously and it's never gonna quite work out exactly how you
want without some pretty complex abstraction mechanisms that are well
beyond the power we need right now.


The thought "screw this, pile the output through /usr/bin/indent" has
crossed my mind more than once.




Bigger fish to fry, but with other languages like rust looming, making 
the core generation facilities nicer might be ...nice. Not for this series.


Two approaches in general would make sense to me:

1. Building an AST for C instead of strings, and rendering the AST.
2. Writing a templating engine that doesn't break the Python indentation 
flow by hoisting them into module constants and improving the rendering 
logic.


--js




Re: [PATCH 06/37] qapi: delint using flake8

2020-09-18 Thread Markus Armbruster
John Snow  writes:

> On 9/17/20 3:54 AM, Markus Armbruster wrote:
>> John Snow  writes:
>> 
>>> On 9/16/20 8:12 AM, Markus Armbruster wrote:
 John Snow  writes:

> Petty style guide fixes and line length enforcement.  Not a big win, not
> a big loss, but flake8 passes 100% on the qapi module, which gives us an
> easy baseline to enforce hereafter.
>
> Signed-off-by: John Snow 
[...]
> diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
> index e1df0e341f..2e4b4de0fa 100644
> --- a/scripts/qapi/commands.py
> +++ b/scripts/qapi/commands.py
> @@ -69,7 +69,8 @@ def gen_call(name, arg_type, boxed, ret_type):
>def gen_marshal_output(ret_type):
>return mcgen('''
>-static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
> QObject **ret_out, Error **errp)
> +static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject 
> **ret_out,
> +  Error **errp)
 The continued parameter list may become misalignd in generated C.
 E.g.
   static void qmp_marshal_output_BlockInfoList(BlockInfoList *ret_in, 
 QObject **ret_out,
 Error **errp)
   {
   ...
   }
 Do we care?

>>>
>>> Yeah, I don't know. Do we?
>> I care, but I also care for automated style checks.
>> 
>>> It actually seemed more annoying to try and get flake8 to make an
>>> exception for these handful of examples.
>>>
>>> Path of least resistance led me here, but I can try and appease both
>>> systems if you'd prefer.
>> Up to now, I ran the style checkers manually, and this was just one
>> of
>> several complaints to ignore, so I left the code alone.
>> If it gets in the way of running them automatically, and messing up
>> the
>> generated code slightly is the easiest way to get it out of the way,
>> then I can accept the slight mess.
>> 
>
> I changed this a little to put all the args on the next line, which is
> slightly unusual but works okay.

I think it's slightly more unusual than the non-matching indentation
was.

Yet another way to skin this cat:

static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
QObject **ret_out, Error **errp)

Now the second line is not aligned with the left parenthesis both in the
Python source and in the generated C.

> I think that's a fine middle ground, because the alternative (to me)
> is to start using abstracted code generation tokens in a tree
> structure, etc etc etc.
>
> Embedded templates are always gonna look kinda nasty, I think, because
> you're trying to fight style guidelines in two languages
> simultaneously and it's never gonna quite work out exactly how you
> want without some pretty complex abstraction mechanisms that are well
> beyond the power we need right now.

The thought "screw this, pile the output through /usr/bin/indent" has
crossed my mind more than once.




Re: [PATCH 06/37] qapi: delint using flake8

2020-09-17 Thread John Snow

On 9/17/20 3:54 AM, Markus Armbruster wrote:

John Snow  writes:


On 9/16/20 8:12 AM, Markus Armbruster wrote:

John Snow  writes:


Petty style guide fixes and line length enforcement.  Not a big win, not
a big loss, but flake8 passes 100% on the qapi module, which gives us an
easy baseline to enforce hereafter.

Signed-off-by: John Snow 
---
   scripts/qapi/.flake8 |  2 ++
   scripts/qapi/commands.py |  3 ++-
   scripts/qapi/schema.py   |  8 +---
   scripts/qapi/visit.py| 15 ++-
   4 files changed, 19 insertions(+), 9 deletions(-)
   create mode 100644 scripts/qapi/.flake8

diff --git a/scripts/qapi/.flake8 b/scripts/qapi/.flake8
new file mode 100644
index 00..45d8146f3f
--- /dev/null
+++ b/scripts/qapi/.flake8
@@ -0,0 +1,2 @@
+[flake8]
+extend-ignore = E722  # Pylint handles this, but smarter.

I guess you mean pylint's W0702 a.k.a. bare-except.  What's wrong
with
flake8's E722 compared to pylint's W0702?



Flake8 will warn on *any* bare except, but Pylint's is context-aware
and will suppress the warning if you re-raise the exception.


Should this information be worked into the comment?



I'll improve it a little, but I'll add what I wrote above to the commit 
message.



I don't actually think this comes up in the qapi code base, but it
does come up in the ./python/qemu code base.

(One of my goals is unifying the lint checking regime for both packages.)


\ No newline at end of file

So put one there :)



Whupps, okay.


diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index e1df0e341f..2e4b4de0fa 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -69,7 +69,8 @@ def gen_call(name, arg_type, boxed, ret_type):
   def gen_marshal_output(ret_type):
   return mcgen('''
   -static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
QObject **ret_out, Error **errp)
+static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out,
+  Error **errp)

The continued parameter list may become misalignd in generated C.
E.g.
  static void qmp_marshal_output_BlockInfoList(BlockInfoList
*ret_in, QObject **ret_out,
Error **errp)
  {
  ...
  }
Do we care?



Yeah, I don't know. Do we?


I care, but I also care for automated style checks.


It actually seemed more annoying to try and get flake8 to make an
exception for these handful of examples.

Path of least resistance led me here, but I can try and appease both
systems if you'd prefer.


Up to now, I ran the style checkers manually, and this was just one of
several complaints to ignore, so I left the code alone.

If it gets in the way of running them automatically, and messing up the
generated code slightly is the easiest way to get it out of the way,
then I can accept the slight mess.



I changed this a little to put all the args on the next line, which is 
slightly unusual but works okay.


I think that's a fine middle ground, because the alternative (to me) is 
to start using abstracted code generation tokens in a tree structure, 
etc etc etc.


Embedded templates are always gonna look kinda nasty, I think, because 
you're trying to fight style guidelines in two languages simultaneously 
and it's never gonna quite work out exactly how you want without some 
pretty complex abstraction mechanisms that are well beyond the power we 
need right now.



More of the same below.


   {
   Visitor *v;
   

[...]






Re: [PATCH 06/37] qapi: delint using flake8

2020-09-17 Thread Markus Armbruster
John Snow  writes:

> On 9/16/20 8:12 AM, Markus Armbruster wrote:
>> John Snow  writes:
>> 
>>> Petty style guide fixes and line length enforcement.  Not a big win, not
>>> a big loss, but flake8 passes 100% on the qapi module, which gives us an
>>> easy baseline to enforce hereafter.
>>>
>>> Signed-off-by: John Snow 
>>> ---
>>>   scripts/qapi/.flake8 |  2 ++
>>>   scripts/qapi/commands.py |  3 ++-
>>>   scripts/qapi/schema.py   |  8 +---
>>>   scripts/qapi/visit.py| 15 ++-
>>>   4 files changed, 19 insertions(+), 9 deletions(-)
>>>   create mode 100644 scripts/qapi/.flake8
>>>
>>> diff --git a/scripts/qapi/.flake8 b/scripts/qapi/.flake8
>>> new file mode 100644
>>> index 00..45d8146f3f
>>> --- /dev/null
>>> +++ b/scripts/qapi/.flake8
>>> @@ -0,0 +1,2 @@
>>> +[flake8]
>>> +extend-ignore = E722  # Pylint handles this, but smarter.
>> I guess you mean pylint's W0702 a.k.a. bare-except.  What's wrong
>> with
>> flake8's E722 compared to pylint's W0702?
>> 
>
> Flake8 will warn on *any* bare except, but Pylint's is context-aware
> and will suppress the warning if you re-raise the exception.

Should this information be worked into the comment?

> I don't actually think this comes up in the qapi code base, but it
> does come up in the ./python/qemu code base.
>
> (One of my goals is unifying the lint checking regime for both packages.)
>
>>> \ No newline at end of file
>> So put one there :)
>> 
>
> Whupps, okay.
>
>>> diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
>>> index e1df0e341f..2e4b4de0fa 100644
>>> --- a/scripts/qapi/commands.py
>>> +++ b/scripts/qapi/commands.py
>>> @@ -69,7 +69,8 @@ def gen_call(name, arg_type, boxed, ret_type):
>>>   def gen_marshal_output(ret_type):
>>>   return mcgen('''
>>>   -static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in,
>>> QObject **ret_out, Error **errp)
>>> +static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject 
>>> **ret_out,
>>> +  Error **errp)
>> The continued parameter list may become misalignd in generated C.
>> E.g.
>>  static void qmp_marshal_output_BlockInfoList(BlockInfoList
>> *ret_in, QObject **ret_out,
>>Error **errp)
>>  {
>>  ...
>>  }
>> Do we care?
>> 
>
> Yeah, I don't know. Do we?

I care, but I also care for automated style checks.

> It actually seemed more annoying to try and get flake8 to make an
> exception for these handful of examples.
>
> Path of least resistance led me here, but I can try and appease both
> systems if you'd prefer.

Up to now, I ran the style checkers manually, and this was just one of
several complaints to ignore, so I left the code alone.

If it gets in the way of running them automatically, and messing up the
generated code slightly is the easiest way to get it out of the way,
then I can accept the slight mess.

>> More of the same below.
>> 
>>>   {
>>>   Visitor *v;
>>>   
>> [...]
>> 




Re: [PATCH 06/37] qapi: delint using flake8

2020-09-16 Thread John Snow

On 9/16/20 8:12 AM, Markus Armbruster wrote:

John Snow  writes:


Petty style guide fixes and line length enforcement.  Not a big win, not
a big loss, but flake8 passes 100% on the qapi module, which gives us an
easy baseline to enforce hereafter.

Signed-off-by: John Snow 
---
  scripts/qapi/.flake8 |  2 ++
  scripts/qapi/commands.py |  3 ++-
  scripts/qapi/schema.py   |  8 +---
  scripts/qapi/visit.py| 15 ++-
  4 files changed, 19 insertions(+), 9 deletions(-)
  create mode 100644 scripts/qapi/.flake8

diff --git a/scripts/qapi/.flake8 b/scripts/qapi/.flake8
new file mode 100644
index 00..45d8146f3f
--- /dev/null
+++ b/scripts/qapi/.flake8
@@ -0,0 +1,2 @@
+[flake8]
+extend-ignore = E722  # Pylint handles this, but smarter.


I guess you mean pylint's W0702 a.k.a. bare-except.  What's wrong with
flake8's E722 compared to pylint's W0702?



Flake8 will warn on *any* bare except, but Pylint's is context-aware and 
will suppress the warning if you re-raise the exception.


I don't actually think this comes up in the qapi code base, but it does 
come up in the ./python/qemu code base.


(One of my goals is unifying the lint checking regime for both packages.)


\ No newline at end of file


So put one there :)



Whupps, okay.


diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
index e1df0e341f..2e4b4de0fa 100644
--- a/scripts/qapi/commands.py
+++ b/scripts/qapi/commands.py
@@ -69,7 +69,8 @@ def gen_call(name, arg_type, boxed, ret_type):
  def gen_marshal_output(ret_type):
  return mcgen('''
  
-static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out, Error **errp)

+static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject **ret_out,
+  Error **errp)


The continued parameter list may become misalignd in generated C.  E.g.

 static void qmp_marshal_output_BlockInfoList(BlockInfoList *ret_in, 
QObject **ret_out,
   Error **errp)
 {
 ...
 }

Do we care?



Yeah, I don't know. Do we?

It actually seemed more annoying to try and get flake8 to make an 
exception for these handful of examples.


Path of least resistance led me here, but I can try and appease both 
systems if you'd prefer.



More of the same below.


  {
  Visitor *v;
  

[...]






Re: [PATCH 06/37] qapi: delint using flake8

2020-09-16 Thread Markus Armbruster
John Snow  writes:

> Petty style guide fixes and line length enforcement.  Not a big win, not
> a big loss, but flake8 passes 100% on the qapi module, which gives us an
> easy baseline to enforce hereafter.
>
> Signed-off-by: John Snow 
> ---
>  scripts/qapi/.flake8 |  2 ++
>  scripts/qapi/commands.py |  3 ++-
>  scripts/qapi/schema.py   |  8 +---
>  scripts/qapi/visit.py| 15 ++-
>  4 files changed, 19 insertions(+), 9 deletions(-)
>  create mode 100644 scripts/qapi/.flake8
>
> diff --git a/scripts/qapi/.flake8 b/scripts/qapi/.flake8
> new file mode 100644
> index 00..45d8146f3f
> --- /dev/null
> +++ b/scripts/qapi/.flake8
> @@ -0,0 +1,2 @@
> +[flake8]
> +extend-ignore = E722  # Pylint handles this, but smarter.

I guess you mean pylint's W0702 a.k.a. bare-except.  What's wrong with
flake8's E722 compared to pylint's W0702?

> \ No newline at end of file

So put one there :)

> diff --git a/scripts/qapi/commands.py b/scripts/qapi/commands.py
> index e1df0e341f..2e4b4de0fa 100644
> --- a/scripts/qapi/commands.py
> +++ b/scripts/qapi/commands.py
> @@ -69,7 +69,8 @@ def gen_call(name, arg_type, boxed, ret_type):
>  def gen_marshal_output(ret_type):
>  return mcgen('''
>  
> -static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject 
> **ret_out, Error **errp)
> +static void qmp_marshal_output_%(c_name)s(%(c_type)s ret_in, QObject 
> **ret_out,
> +  Error **errp)

The continued parameter list may become misalignd in generated C.  E.g.

static void qmp_marshal_output_BlockInfoList(BlockInfoList *ret_in, QObject 
**ret_out,
  Error **errp)
{
...
}

Do we care?

More of the same below.

>  {
>  Visitor *v;
>  
[...]