On 5/28/2014 2:24 PM, Gedare Bloom wrote:
> On Wed, May 28, 2014 at 2:49 PM, Joel Sherrill
> <joel.sherr...@oarcorp.com> wrote:
>> On 5/28/2014 10:22 AM, Gedare Bloom wrote:
>>> On Wed, May 28, 2014 at 11:05 AM, Joel Sherrill
>>> <joel.sherr...@oarcorp.com> wrote:
>>>> On 5/28/2014 7:39 AM, Gedare Bloom wrote:
>>>>> On Wed, May 28, 2014 at 5:00 AM, Sebastian Huber
>>>>> <sebastian.hu...@embedded-brains.de> wrote:
>>>>>> On 2014-05-28 00:16, Joel Sherrill wrote:
>>>>>>> - rtems/score/threadimpl.h: _Thread_Start_multitasking does return
>>>>>>> on Scheduler Simulator. Initializing RTEMS returns to the command
>>>>>>> interpreter.
>>>>>>>
>>>>>>> - rtems/score/smpimpl.h:
>>>>>>> _SMP_Start_multitasking_on_secondary_processor()
>>>>>>> is not applicable on the Scheduler Simulator and the no return
>>>>>>> attribute
>>>>>>> gives a warning.
>>>>>>>
>>>>>>> - rtems/score/assert.h: Scheduler Simulator uses glibc assert.h on
>>>>>>> GNU/Linux.
>>>>>>> This will likely need to be adjusted more for other host compilers
>>>>>>> and
>>>>>>> C libraries
>>>>>>>
>>>>>>> - threadrestart.c: Disable assert on Scheduler Simulator. Restarting
>>>>>>> self
>>>>>>> returns to the command interpreter.
>>>>>> I would define RTEMS_COMPILER_NO_RETURN_ATTRIBUTE and _Assert() to
>>>>>> nothing
>>>>>> in case RTEMS_SCHEDSIM is defined. Do you really need this debugging
>>>>>> stuff
>>>>>> for the scheduler simulator? I don't think we should propagate oddities
>>>>>> of
>>>>>> the scheduler simulator throughout the code base.
>>>>>>
>>>>> Yes, this was my initial reaction as well. Probably at least you could
>>>>> make Assert_Not_reached() a nop, or write a wrapper for assert that
>>>>> depends on schedsim. Can schedsim work more like a real target for
>>>>> this case of not returning? I guess usually the system ends up in a
>>>>> fatal or halt state? Maybe you can interpose on that state to return
>>>>> to the command interpreter.
>>>> Schedsim does not really context switch so the paths that assume a task
>>>> switches
>>>> out and never returns are reachable paths. It is logically a single
>>>> thread of control
>>>> with the underlying RTEMS code thinking that a thread is "executing" on
>>>> the various
>>>> cores. When a thread blocks, control returns to the script with a new
>>>> executing
>>>> thread. In an SMP configuration, the scripts can also change CPU focus
>>>> and execute
>>>> commands in the context of the executing thread on that core.
>>>>
>>>> I can live with disabling the noreturn checks and turning off that
>>>> warning. I think
>>>> that will eliminate the first two of the four spots touched above.
>>>>
>>>> But I don't want to disable the asserts. Right now, we can run with
>>>> --enable-rtems-debug
>>>> and not get any asserts. The consistency checks are really handy and
>>>> they found
>>>> bugs in the Affinity Scheduler. So I really do not want to disable
>>>> them. So killing
>>>> assertions is undesirable.
>>>>
>>>> I could try to move all of the alternative assert logic under an
>>>> RTEMS_SCHEDSIM.
>>>> That would make it clearer what it is for and harder to trip.
>>>>
>>>> For know, making Assert_Not_reached() nothing on Schedsim would be
>>>> acceptable
>>>> for the _Thread_Restart() assertion.
>>>>
>>>> I think this would restrict the patch to the rtems assert.h. Is that
>>>> acceptable?
>>>>
>>> Yes, that would be better.
>> I can't turn off the no return warning via the command line. That
>> touches basedefs.h.
>>
>> So basedefs.h and assert.h are the reduced set of files touched.
>>
>> New version attached.
> You changed to using #if instead of #if defined. I think you want it
> with the ifdef.
How about this one? I tried to stay consistent in style with what was
already in the file.
But defined(X) or defined( X ) in the rules?
> -Gedare
--
Joel Sherrill, Ph.D. Director of Research & Development
joel.sherr...@oarcorp.com On-Line Applications Research
Ask me about RTEMS: a free RTOS Huntsville AL 35805
Support Available (256) 722-9985
>From 7a64865a4c609e45855e08ef7f308dcc6cc3ce48 Mon Sep 17 00:00:00 2001
From: Joel Sherrill <joel.sherr...@oarcorp.com>
Date: Mon, 14 Apr 2014 16:05:04 -0500
Subject: [PATCH 1/4] Minor conditionals to enable building Scheduler Simulator on GNU/Linux
- rtems/score/assert.h: Scheduler Simulator uses glibc assert.h on GNU/Linux.
This will likely need to be adjusted more for other host compilers and
C libraries. Also disable _Assert_Not_reached() because some of these
paths do actually return to the called on the Scheduler Simulator.
- basedefs.h: Do not use noreturn attribute when on Scheduler Simulator.
Paths which context switch can return to the command interpreter on
the Scheduler Simulator.
---
cpukit/score/include/rtems/score/assert.h | 26 ++++++++++++++++++++++----
cpukit/score/include/rtems/score/basedefs.h | 4 +++-
2 files changed, 25 insertions(+), 5 deletions(-)
diff --git a/cpukit/score/include/rtems/score/assert.h b/cpukit/score/include/rtems/score/assert.h
index 41ef1ae..3d3bf78 100644
--- a/cpukit/score/include/rtems/score/assert.h
+++ b/cpukit/score/include/rtems/score/assert.h
@@ -30,10 +30,24 @@ extern "C" {
* NDEBUG.
*/
#if defined( RTEMS_DEBUG )
- #define _Assert( _e ) \
- ( ( _e ) ? \
- ( void ) 0 : \
- __assert_func( __FILE__, __LINE__, __ASSERT_FUNC, #_e ) )
+ #if !defined( RTEMS_SCHEDSIM )
+ /* __ASSERT_FUNC is newlib. */
+ #define _Assert( _e ) \
+ ( ( _e ) ? \
+ ( void ) 0 : \
+ __assert_func( __FILE__, __LINE__, __ASSERT_FUNC, #_e ) )
+ #else
+ /* __ASSERT_FUNCTION is glibc. */
+ #if defined(__ASSERT_FUNCTION)
+ #define _Assert( _e ) \
+ ( ( _e ) ? \
+ ( void ) 0 : \
+ __assert_fail( #_e, __FILE__, __LINE__, __ASSERT_FUNCTION ) )
+ #else
+ #error "What does assert.h use?"
+ #endif
+ #endif
+
#else
#define _Assert( _e ) ( ( void ) 0 )
#endif
@@ -70,7 +84,11 @@ extern "C" {
/**
* @brief Asserts that this point is not reached during run-time.
*/
+#if RTEMS_SCHEDSIM
+#define _Assert_Not_reached()
+#else
#define _Assert_Not_reached() _Assert( 0 )
+#endif
#ifdef __cplusplus
}
diff --git a/cpukit/score/include/rtems/score/basedefs.h b/cpukit/score/include/rtems/score/basedefs.h
index a0bebdd..382a97a 100644
--- a/cpukit/score/include/rtems/score/basedefs.h
+++ b/cpukit/score/include/rtems/score/basedefs.h
@@ -153,7 +153,9 @@
* can impact the code generated following calls to
* rtems_fatal_error_occurred and _Terminate.
*/
-#ifdef __GNUC__
+#if defined(RTEMS_SCHEDSIM)
+ #define RTEMS_COMPILER_NO_RETURN_ATTRIBUTE
+#elif defined(__GNUC__)
#define RTEMS_COMPILER_NO_RETURN_ATTRIBUTE \
__attribute__ ((noreturn))
#else
--
1.7.1
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