Misc. Build Options
Command line flags that are less commonly used and don’t usually impact the build.
Disable outputting debug symbols. This can be useful for WebAssembly, as there is no debugger for .wasm files yet and .wasm files are generally served directly. Avoiding debug symbols can have a big impact on generated binary size, reducing them by more than half.
This is not necessary on microcontrollers because debugging symbols are not flashed to the microcontroller. Additionally, you will need it when you use
tinygo gdb. In general, it is recommended to include debug symbols unless you have a good reason not to.
Note: while there is some support for debug symbols, only line numbers have been implemented so far. That means single-stepping and stacktraces work just fine, but no variables can be inspected.
Print size (
full) of the output (linked) binary. Note that the calculated size includes RAM reserved for the stack.
Print size statistics, roughly like what the
size binutils program would print but with useful flash and RAM columns:
code data bss | flash ram
5780 144 2132 | 5924 2276
Try to determine per package how much space is used. Note that these calculations are merely guesses and can somethimes be way off due to various reasons like inlining:
code rodata data bss | flash ram | package
876 0 4 0 | 880 4 | (bootstrap)
38 0 0 0 | 38 0 | device/arm
0 0 0 66 | 0 66 | machine
2994 440 124 0 | 3558 124 | main
948 127 4 1 | 1079 5 | runtime
4856 567 132 67 | 5555 199 | (sum)
5780 - 144 2132 | 5924 2276 | (all)
Print heap allocations in the program and why they happen. You can use
-print-allocs=. if you want to see all heap allocations in the program. You can also match the function name, for example you can use
-print-allocs=strconv to print heap allocations that contain the
strconv substring (which includes all functions from the strconv standard library package).