Compiler: How to See the Size of a Symbol

Mr user4642853

Part Number: TMS570LS3137

Tool/software: TI C/C++ Compiler

For detailed analysis of the software memory usage I would like to see the granular segmentation of each memory sections and their usage.
(using TI Compiler 5.1.6)

Currently in the mapfile I can see:

which sections and regions are used, how much space they require/got allocated for them
what objects I have and in which section they place the symbols and where the symbol starts in the memory space (but not the size!)

I would like to see more detailed information: i would like to know how much space the symbol requires, this information should be available and known for the compiler/linker.

e.g. I have a section ".normal_task_ram" place in internal RAM (lets say starting at 0x8000) of the TMS570 and into this section the obj "normal_task1" places 2 variables with the size of 20 and 40bytes, the I would expect something like this:

================================================================================

normal_task.obj

Run/Load            
Value     Size      Binding   Name (Section)
--------  --------  --------  ---------------
00008000  00000014     local     normal_task_var1 (.normal_task_ram:normal_task_var1)
00008050  00000028     global    normal_task_var2 (.normal_task_ram:normal_task_var1)

Is this somehow possible for the linker to output the detailed information?

My best idea currently is to parse the mapfile and try to figure out which variable consumes the RAM by subtracting the addresses of the symbols in a given section, this is far by not accurate as there might be holes or the last symbol might be just placed at the end region where nothing follows but hollow ram region.

I found and checked the TI cg_xml tool, also checked the "xml_output" but none of them seems to be capable of what I'm trying to access here: simply the information from the linker output seems to be missing.

Is there a way to achieve my goal?

over 8 years ago

0 Archaeologist over 8 years ago

TI__Guru* 84285 points

I will assume you are using EABI. The compiler populates the ELF symbol size field for variables, so if you look at the ELF symbol with a tool like armofd, you'll be able to see the size of an object. Since 2016 (ARM compiler 16.12.0.STS or later), the assembler will also populate the ELF size for functions, as long as the default level of DWARF debugging is present (no option necessary).

0 Mr user4642853 over 8 years ago in reply to Archaeologist

Intellectual 425 points

So if I understood you right the answer is no, there is no way to get this information (size of a symbol that resides in memory) from the map/elf file. Neither with 5.1.6 or a later compiler.

0 Archaeologist over 8 years ago in reply to Mr user4642853

TI__Guru* 84285 points

Yes, you can see the size of variables from the ELF symbol, just not in the map file. You need to use "armofd -v a.out" and look for "Symbol Table"

0 Mr user4642853 over 8 years ago in reply to Archaeologist

Intellectual 425 points

I did that.

"armofd.exe --output=out.txt --obj_display=all --dwarf --dwarf_display=all app.out"

in the generated out.txt there is no symbol table, the variables are there but only their start address, where they were placed.

0 Archaeologist over 8 years ago in reply to Mr user4642853

TI__Guru* 84285 points

You're still missing the verbose (-v) option. Use:

armofd.exe --output=out.txt --verbose app.out

0 Mr user4642853 over 8 years ago in reply to Archaeologist

Intellectual 425 points

Thank you the verbosity is the key indeed i was missing.

Thought that only prints to console.

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Compiler: How to See the Size of a Symbol