Rust hello world binary file size is huge

I am new to the rust language. When i compare my rust hello world program binary with c/c++ hello world program binary i found huge size difference. My rust binary size is 3.1MB and c/c++ binary size is 128KB. I tried google to know why the the size is so huge. And i come to know that rust by default do the static linking due to this the size is increasing. Can any one please correct me if i am wrong. And if this the case please tell me how can i reduce my binary size for hello world program. Using cargo i tried both develop and release binary and in both the case the binary size is 3.1MB.

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Have you already had a look at this StackOverflow post?

I think it sums up the point pretty well.

I have recently shipped a stand-alone binary application in Rust and I found that if you want to look into optimizing your binary size, min-sized-rust is a good starting point.


@MaximilianKoestler thank you very much for your help. Now i am able to create my binary with 1.2MB. Now all most it reduced to around 70% after adding below option in Cargo.toml which one i found from you git hub.

opt-level = 'z'     # Optimize for size.
lto = true          # Enable Link Time Optimization
codegen-units = 1   # Reduce number of codegen units to increase optimizations.
panic = 'abort'     # Abort on panic  

Can you please tell me how can i pass this option from command line means if i want to compile using "rustc <>" .In this case how can i pass the options.

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-C ...: Codegen options - The rustc book

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You can run cargo build -v to see the options that Cargo passes to rustc. They will include something like this:

rustc -C opt-level=z -C lto -C codegen-units=1 -C panic=abort

Thank you very much. Really very much helpful.

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@mbrubeck and @vitalyd Thank you very much. Really very much helpful.

Can you elaborate on why you want to compile directly with rustc instead of cargo build?

You can pass compiler flags to rustc from cargo via a dedicated config file, which I have found to be a superior solution when compared to calling rustc directly in most cases.

@MaximilianKoestler Yes i fully agree with you that using cargo is the best solution. But just i wanted to know how to pass with out config file. Now i got my answer. Thank you.

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