FreeRTOS 4.0.4, GCC: Inlining

thomas_nittel wrote on Wednesday, July 19, 2006:


when the module FreeRTOSV4.0.4\FreeRTOS\Source\portable\GCC\ARM7_AT91SAM7S\portISR.c is compiled with arm-elf-gcc 4.1.0 the following warning appears

Source/portable/GCC/ARM7_AT91SAM7S/portISR.c -o portISR.o
…/…/Source/FreeRTOS_4.0.4/Source/portable/GCC/ARM7_AT91SAM7S/portISR.c: In function ‘vPreemptiveTick’:
…/…/Source/FreeRTOS_4.0.4/Source/include/task.h:832: warning: inlining failed in call to ‘vTaskIncrementTick’: function body not available
…/…/Source/FreeRTOS_4.0.4/Source/portable/GCC/ARM7_AT91SAM7S/portISR.c:144: warning: called from here

Obviously inlining doesn’t work with GCC.

gcc.pdf, page 216 recommends to put the function definition in a header file with the keywords inline and extern.
If ‘vTaskIncrementTick’ is put as ‘extern inline void vTaskIncrementTick( void )’ in ‘task.h’ inlining will work with GCC, too. Of cause some declarations of variables, functions and macros of ‘tasks.c’ are addtionally necessary in ‘task.h’.

I found the above mentioned document at Its title is ‘Using the GNU Compiler Collection’ for GCC 3.3.2 and dated from 20. December 2002. A newer version doesn’t seem to be available.

The compiler command which I used is
arm-elf-gcc -c -I…/…/Source/Demo -I…/…/Source/FreeRTOS_4.0.4/Source/include -I…/…/Source/FreeRTOS_4.0.4/Source/portable/GCC/ARM7_AT91SAM7S -I…/…/Source/Utilities -Wall -Wextra -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations -Wno-strict-aliasing -Winline -D THUMB_INTERWORK -D SAM7_GCC -mthumb-interwork -mcpu=arm7tdmi -MMD -finline-limit=1000  -Os …/…/Source/FreeRTOS_4.0.4/Source/portable/GCC/ARM7_AT91SAM7S/portISR.c -o portISR.o

Best regards


nobody wrote on Wednesday, July 19, 2006:

The inline is a legacy thing.  Most portmacro.h files include the lilne

#define inline

to remove it from the code and prevent any warnings.

thomas_nittel wrote on Wednesday, July 19, 2006:

of cause warnings can be avoided this way. But I want my code to be inlined so that the function call overhead is spared. For an example see my posting ‘RE: FreeRTOS 4.0.4, AT91SAM7X256, Timertick
2006-07-19 14:05’