This commit improves accuracy of the -size=full flag in a big way.
Instead of relying on symbol names to figure out by which package
symbols belong, it will instead mostly use DWARF debug information
(specifically, debug line tables and debug information for global
variables) relying on symbols only for some specific things. This is
much more accurate: it also accounts for inlined functions.
For example, here is how it looked previously when compiling a personal
project:
code rodata data bss | flash ram | package
1902 333 0 0 | 2235 0 | (bootstrap)
46 256 0 0 | 302 0 | github
0 454 0 0 | 454 0 | handleHardFault$string
154 24 4 4 | 182 8 | internal/task
2498 83 5 2054 | 2586 2059 | machine
0 16 24 130 | 40 154 | machine$alloc
1664 32 12 8 | 1708 20 | main
0 0 0 200 | 0 200 | main$alloc
2476 79 0 36 | 2555 36 | runtime
576 0 0 0 | 576 0 | tinygo
9316 1277 45 2432 | 10638 2477 | (sum)
11208 - 48 6548 | 11256 6596 | (all)
And here is how it looks now:
code rodata data bss | flash ram | package
------------------------------- | --------------- | -------
1509 0 12 23 | 1521 35 | (unknown)
660 0 0 0 | 660 0 | C compiler-rt
58 0 0 0 | 58 0 | C picolibc
0 0 0 4096 | 0 4096 | C stack
174 0 0 0 | 174 0 | device/arm
6 0 0 0 | 6 0 | device/sam
598 256 0 0 | 854 0 | github.com/aykevl/ledsgo
320 24 0 4 | 344 4 | internal/task
1414 99 24 2181 | 1537 2205 | machine
726 352 12 208 | 1090 220 | main
3002 542 0 36 | 3544 36 | runtime
848 0 0 0 | 848 0 | runtime/volatile
70 0 0 0 | 70 0 | time
550 0 0 0 | 550 0 | tinygo.org/x/drivers/ws2812
------------------------------- | --------------- | -------
9935 1273 48 6548 | 11256 6596 | total
There are some notable differences:
* Odd packages like main$alloc and handleHardFault$string are gone,
instead their code is put in the correct package.
* C libraries and the stack are now included in the list, they were
previously part of the (bootstrap) pseudo-package.
* Unknown bytes are slightly reduced. It should be possible to reduce
it significantly more in the future: most of it is now caused by
interface invoke wrappers.
* Inlined functions are now correctly attributed. For example, the
runtime/volatile package is normally entirely inlined.
* There is no difference between (sum) and (all) anymore. A better
code size algorithm now counts the code/data sizes correctly.
* And last (but not least) there is a stylistic change: the table now
looks more like a table. Especially the summary should be clearer
now.
Future goals:
* Improve debug information so that the (unknown) pseudo-package is
reduced in size or even eliminated altogether.
* Add support for other file formats, most importantly WebAssembly.
* Perhaps provide a way to expand this report per file, or in a
machine-readable format like JSON or CSV.
5792f3a1cf