Re: sizeof(function) functionality

[Erik Christiansen <erik at dd dot nec dot com dot au>]

   Have you considered just doing a gcc -Wl,M to ask the linker to
   generate a link map? (Invoking ld directly, I give it the -M without
   going through gcc.)

   Admittedly, this works only for functions of global scope, so you'd
   have to expose deeper functions for the duration of the measurement.

   e.g. Four functions from a current map (sorted):

 .text          0x00104ce0      0x230 obj/brt_led.o
                0x00104ce0                leds
                0x00104d68                init_led
                0x00104de8                watchdog_timer
                0x00104e18                timeout
 .text          0x00104f10       0xdc obj/compatibility_stubs.o

   The total size of the 4 is already given (0x230), and a few lines of
   awk or perl can do 0x00104e18 - 0x00104de8 = 0x30, to show that
   watchdog_timer is 48 bytes long. (bc for one-off, by hand)

   To report on local-scope stuff, what about doing gcc -g (to include
   debugging information), then objdump -S your_object_file, to provide
   a nice listing like:

00104de8 <watchdog_timer>:

void watchdog_timer(void)
{

   ...                        // Assembler omitted, to spare the
                              // squeamish.
}

...

00104e18 <timeout>:

void timeout(void)                       // Timer interrupt handler.
{

   ...
}

   A few seconds with bc gives the size of a particular function. Again,
   a few lines of awk can report on function sizes for the whole
   executable.

   YMMV

Regards,
Erik