c++ - g++ compiler flag to minimize binary size

Question

I'm have an Arduino Uno R3. I'm making logical objects for each of my sensors using C++. The Arduino has very limited on-board memory 32KB*, and, on average, my compiled objects are coming out around 6KB*.

I am already using the smallest possible data types required, in an attempt to minimize my memory footprint. Is there a compiler flag to minimize the size of the binary, or do I need to use shorter variable and function names, less functions, etc. to minimize my code base?

Also, any other tips or words of advice for minimizing binary size would be appreciated.

*It may not be measured in KB (as I don't have it sitting in front of me), but 1 object is approximately 1/5 of my total memory size, which is prompting my concern.

Answer 1

There are lots of techniques to reduce binary size in addition to what us2012 and others mentioned in the comments, summing them up with some points of my own:

• Use -Os to make gcc/g++ optimize for size.
• Use -ffunction-sections -fdata-sections to separate each function or data into distinct sections within the translation unit. Combine it with the linker option -Wl,--gc-sections to get rid of any unreferenced sections.
• Run strip with at least the following options: -s -R .comment -R .gnu.version. It can be combined with --strip-unneeded to remove all symbols that are not necessary for relocation processing.