diff mbox series

build: Make python output print to stdout when running with -v (verbose)

Message ID 20230309192138.991-1-mark.asselstine@windriver.com
State Accepted, archived
Commit 81a58647b2f4fc0a2589b2978fc9d81b2bfe6aec
Headers show
Series build: Make python output print to stdout when running with -v (verbose) | expand

Commit Message

Mark Asselstine March 9, 2023, 7:21 p.m. UTC
When tasks are run with -v (verbose) on the bitbake commandline, shell
tasks print their stdout, python tasks do not.

This change redirects the python task's print output to an in memory
buffer. After the task is executed the output is printed to stdout via
the logger. This makes the python task behavior match the shell task
behavior when running with -v. The contents of the task's log files
remain unchanged after this change.

This approach should keep the correct order in most cases, however, if
the python task accesses the logger directly, that content will appear
before other output. On the other hand, this change should negate the
need for python tasks to access the logger directly.

The following example will produce out-of-order output

--
python do_build() {
   print("Start")
   bb.plain("********************");
   bb.plain("*                  *");
   bb.plain("*  Hello, World!   *");
   bb.plain("*                  *");
   bb.plain("********************");
   print("Finish")
}
--
will output
--
********************
*                  *
*  Hello, World!   *
*                  *
********************
Start
Finish
--

The logging-test.bb in meta-selftest or the above 'hello world!' can
be used to review this change.

[Yocto #14544]

Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
---
 lib/bb/build.py | 9 +++++++++
 1 file changed, 9 insertions(+)

Comments

Richard Purdie March 9, 2023, 9:49 p.m. UTC | #1
On Thu, 2023-03-09 at 14:21 -0500, Mark Asselstine wrote:
> When tasks are run with -v (verbose) on the bitbake commandline, shell
> tasks print their stdout, python tasks do not.
> 
> This change redirects the python task's print output to an in memory
> buffer. After the task is executed the output is printed to stdout via
> the logger. This makes the python task behavior match the shell task
> behavior when running with -v. The contents of the task's log files
> remain unchanged after this change.
> 
> This approach should keep the correct order in most cases, however, if
> the python task accesses the logger directly, that content will appear
> before other output. On the other hand, this change should negate the
> need for python tasks to access the logger directly.
> 
> The following example will produce out-of-order output
> 
> --
> python do_build() {
>    print("Start")
>    bb.plain("********************");
>    bb.plain("*                  *");
>    bb.plain("*  Hello, World!   *");
>    bb.plain("*                  *");
>    bb.plain("********************");
>    print("Finish")
> }
> --
> will output
> --
> ********************
> *                  *
> *  Hello, World!   *
> *                  *
> ********************
> Start
> Finish
> --
> 
> The logging-test.bb in meta-selftest or the above 'hello world!' can
> be used to review this change.
> 
> [Yocto #14544]
> 
> Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
> ---
>  lib/bb/build.py | 9 +++++++++
>  1 file changed, 9 insertions(+)
> 
> diff --git a/lib/bb/build.py b/lib/bb/build.py
> index 5a172711..eb2d5b59 100644
> --- a/lib/bb/build.py
> +++ b/lib/bb/build.py
> @@ -25,6 +25,7 @@ import bb
>  import bb.msg
>  import bb.process
>  import bb.progress
> +from io import StringIO
>  from bb import data, event, utils
>  
>  bblogger = logging.getLogger('BitBake')
> @@ -296,9 +297,17 @@ def exec_func_python(func, d, runfile, cwd=None):
>          lineno = int(d.getVarFlag(func, "lineno", False))
>          bb.methodpool.insert_method(func, text, fn, lineno - 1)
>  
> +        if verboseStdoutLogging:
> +            sys.stdout.flush()
> +            sys.stdout = execio = StringIO()
>          comp = utils.better_compile(code, func, "exec_func_python() autogenerated")
>          utils.better_exec(comp, {"d": d}, code, "exec_func_python() autogenerated")
>      finally:
> +        if verboseStdoutLogging:
> +            execio.flush()
> +            logger.plain("%s" % execio.getvalue())
> +            sys.stdout = sys.__stdout__
> +            execio.close()
>          # We want any stdout/stderr to be printed before any other log messages to make debugging
>          # more accurate. In some cases we seem to lose stdout/stderr entirely in logging tests without this.
>          sys.stdout.flush()

From memory, I think exec_func_python can get called recursively so I
suspect this is going to corrupt sys.stdout. You could save it's value,
then restore it?

Also, what about stderr?

Cheers,

Richard
Mark Asselstine March 9, 2023, 9:54 p.m. UTC | #2
On 3/9/2023 4:49 PM, Richard Purdie wrote:
> On Thu, 2023-03-09 at 14:21 -0500, Mark Asselstine wrote:
>> When tasks are run with -v (verbose) on the bitbake commandline, shell
>> tasks print their stdout, python tasks do not.
>>
>> This change redirects the python task's print output to an in memory
>> buffer. After the task is executed the output is printed to stdout via
>> the logger. This makes the python task behavior match the shell task
>> behavior when running with -v. The contents of the task's log files
>> remain unchanged after this change.
>>
>> This approach should keep the correct order in most cases, however, if
>> the python task accesses the logger directly, that content will appear
>> before other output. On the other hand, this change should negate the
>> need for python tasks to access the logger directly.
>>
>> The following example will produce out-of-order output
>>
>> --
>> python do_build() {
>>     print("Start")
>>     bb.plain("********************");
>>     bb.plain("*                  *");
>>     bb.plain("*  Hello, World!   *");
>>     bb.plain("*                  *");
>>     bb.plain("********************");
>>     print("Finish")
>> }
>> --
>> will output
>> --
>> ********************
>> *                  *
>> *  Hello, World!   *
>> *                  *
>> ********************
>> Start
>> Finish
>> --
>>
>> The logging-test.bb in meta-selftest or the above 'hello world!' can
>> be used to review this change.
>>
>> [Yocto #14544]
>>
>> Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
>> ---
>>   lib/bb/build.py | 9 +++++++++
>>   1 file changed, 9 insertions(+)
>>
>> diff --git a/lib/bb/build.py b/lib/bb/build.py
>> index 5a172711..eb2d5b59 100644
>> --- a/lib/bb/build.py
>> +++ b/lib/bb/build.py
>> @@ -25,6 +25,7 @@ import bb
>>   import bb.msg
>>   import bb.process
>>   import bb.progress
>> +from io import StringIO
>>   from bb import data, event, utils
>>   
>>   bblogger = logging.getLogger('BitBake')
>> @@ -296,9 +297,17 @@ def exec_func_python(func, d, runfile, cwd=None):
>>           lineno = int(d.getVarFlag(func, "lineno", False))
>>           bb.methodpool.insert_method(func, text, fn, lineno - 1)
>>   
>> +        if verboseStdoutLogging:
>> +            sys.stdout.flush()
>> +            sys.stdout = execio = StringIO()
>>           comp = utils.better_compile(code, func, "exec_func_python() autogenerated")
>>           utils.better_exec(comp, {"d": d}, code, "exec_func_python() autogenerated")
>>       finally:
>> +        if verboseStdoutLogging:
>> +            execio.flush()
>> +            logger.plain("%s" % execio.getvalue())
>> +            sys.stdout = sys.__stdout__
>> +            execio.close()
>>           # We want any stdout/stderr to be printed before any other log messages to make debugging
>>           # more accurate. In some cases we seem to lose stdout/stderr entirely in logging tests without this.
>>           sys.stdout.flush()
> 
>  From memory, I think exec_func_python can get called recursively so I
> suspect this is going to corrupt sys.stdout. You could save it's value,
> then restore it?
> 

I was actually dithering on this and was saving and restoring it in my 
first iteration. I opted for simplicity when I believed that it was 
allways going to be __stdout__. Regardless if it every changes it would 
be safer to save and restore. I will return to that approach in V2.

> Also, what about stderr?

Tunnel vision at play, I was only focused on stdout :). It should be 
simple to add stderr and I will do so in V2.

MarkA

> 
> Cheers,
> 
> Richard
>
diff mbox series

Patch

diff --git a/lib/bb/build.py b/lib/bb/build.py
index 5a172711..eb2d5b59 100644
--- a/lib/bb/build.py
+++ b/lib/bb/build.py
@@ -25,6 +25,7 @@  import bb
 import bb.msg
 import bb.process
 import bb.progress
+from io import StringIO
 from bb import data, event, utils
 
 bblogger = logging.getLogger('BitBake')
@@ -296,9 +297,17 @@  def exec_func_python(func, d, runfile, cwd=None):
         lineno = int(d.getVarFlag(func, "lineno", False))
         bb.methodpool.insert_method(func, text, fn, lineno - 1)
 
+        if verboseStdoutLogging:
+            sys.stdout.flush()
+            sys.stdout = execio = StringIO()
         comp = utils.better_compile(code, func, "exec_func_python() autogenerated")
         utils.better_exec(comp, {"d": d}, code, "exec_func_python() autogenerated")
     finally:
+        if verboseStdoutLogging:
+            execio.flush()
+            logger.plain("%s" % execio.getvalue())
+            sys.stdout = sys.__stdout__
+            execio.close()
         # We want any stdout/stderr to be printed before any other log messages to make debugging
         # more accurate. In some cases we seem to lose stdout/stderr entirely in logging tests without this.
         sys.stdout.flush()