Rust hello world binary file size is huge

help
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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?
https://stackoverflow.com/a/29008355/7317517

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.

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@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.

[profile.release]
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 <file.rs>" .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
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Thank you very much. Really very much helpful.

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

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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.

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@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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