Tool to analyze size of ELF sections and symbol

Question

I need a way to analyze output file of my GCC compiler for ARM. I am compiling for bare metal and I am quite concerned with size. I can use arm-none-eabi-objdump provided by the cross-compiler but parsing the output is not something I would be eager to do if there exists a tool for this task. Do you know of such a tool existing? My search turned out no results.

One more thing, every function in my own code is in its own section.

What are you trying to do? What kind of information do you want to retrieve? — ouah, Jul 30 '12 at 11:32

score 92 · Accepted Answer · answered Jul 30 '12 at 11:39

92

You can use nm and size to get the size of functions and ELF sections.

To get the size of the functions (and objects with static storage duration):

$ nm --print-size --size-sort --radix=d tst.o

The second column shows the size in decimal of function and objects.

To get the size of the sections:

$ size -A -d tst.o

The second column shows the size in decimal of the sections.

answered Jul 30 '12 at 11:39

ouah

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`nm`, isn't that Windows? If so, sorry - I did not say I am using Linux. – RushPL Jul 30 '12 at 19:50
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Windows? No, `nm` and `size` are GNU tools part and are a part of the `binutils`. Add the required platform prefix to run the tools in a cross platform (e.g., type `arm-none-eabi-nm` and `arm-none-eabi-size`), – ouah Jul 30 '12 at 21:28
Interestingly, this also has the size-effect of removing ARM's [Mapping Symbols](https://sourceware.org/binutils/docs-2.20/as/ARM-Mapping-Symbols.html). These symbols are printed without a size field (i.e. the field is missing, not printed as zero), and they are removed when `nm` is used with `--size-sort`. – sherrellbc Sep 21 '17 at 17:56

Lance Richardson · Answer 2 · 2012-07-31T15:31:15.057

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The readelf utility is handy for displaying a variety of section information, including section sizes, e.g.:

arm-none-eabi-readelf -e foo.o

If you're interested in the run-time memory footprint, you can ignore the sections that do not have the 'A' (allocate) flag set.

edited Jul 31 '12 at 15:31

answered Jul 30 '12 at 14:18

Lance Richardson

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`arm-none-eabi-readelf -s build/program.out|perl -ne 'if(/(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)\s+(\S+)/) { print $3 . " " . $8. "\n";}'|sort -n` – RushPL Jul 30 '12 at 19:48
Thank you, the above did the trick for me! I did not know about the readelf. – RushPL Jul 30 '12 at 19:49

score 4 · Answer 3 · answered Oct 28 '22 at 12:31

4

When re-visiting this question 10 years later one must mention the little Python-based wrapper for readelf and nm that is elf-size-analyze:

answered Oct 28 '22 at 12:31

stefanct

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score 0 · Answer 4 · answered Oct 07 '19 at 19:22

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puncover uses objdump and a few other gcc tools to generate html pages you can easily browse to figure out where your code and data space is going.

It's a much nicer frontend than the text output of the gcc tools.

answered Oct 07 '19 at 19:22

sarfata

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Tool to analyze size of ELF sections and symbol

4 Answers4

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