> and you get the following from objdump:
>[ 20](sec 4)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x0000000000000000
>test_struct
>[ 21](sec 4)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x0000000000000024 a
>[ 22](sec 4)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x0000000000000028 b
>With the section size of 0x40. In fact, when adding another copy of the test
>structure after a, you will get the second one starting at 0x40, with a
>section size of 0x80. This is no >optimization, by the way.
>NOTE: this is without ANY optimization flags. If you compile with -O1, you get
>[ 20](sec 7)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x0000000000000000 b
>[ 21](sec 7)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x0000000000000004 a
>[ 22](sec 7)(fl 0x00)(ty 0)(scl 2) (nx 0) 0x0000000000000020
>test_struct
Well, yes, I suppose the location of variables in a single section is not
deterministic.
But I'm using only one variable per section (actually I'm using -data-sections
option),
and am arranging the sections in the linker script to create a memory region
that can be mmaped form external file.
The linker script looks something like this:
.mmaped_region BLOCK(__section_alignment__) : SUBALIGN(1)
{
*(.test_section1)
*(.test_section2)
}
The problem is that by default test_section1 is too big because of the padding,
and test_section2 ends up in the wrong place.
Best regards,
Piotr Madalinski.
TRW Polska Sp. z o.o., ul. Rolnicza 33, 42-200 Czestochowa,
Sad Rejonowy w Czestochowie, KRS nr 0000077409
NIP nr 573-010-52-34, kapital zakladowy: 79.581.975 PLN
TRW Polska Sp. z o.o. Rolnicza 33 Str., 42-200 Czestochowa, Poland
District Court for Czestochowa, KRS no. 0000077409,
tax identification no. NIP 573-010-52-34, share capital: 79.581.975 PLN
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