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On Tuesday, May 14, 2019 3:01:48 PM PDT Andrew Savchenko wrote: |
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> On Tue, 14 May 2019 11:47:04 -0700 Georgy Yakovlev wrote: |
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> > On Tuesday, May 14, 2019 9:15:52 AM PDT Andrew Savchenko wrote: |
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> > > Hi all! |
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> > > |
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> > > Looks like rustc supports target CPU and optlevel options, e.g. |
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> > > |
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> > > rustc -C target-cpu=skylake -C opt-level=3 |
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> > > |
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> > > as well as more fine-grade optimizations. |
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> > > |
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> > > But I see no way to specify them when building rust software. |
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> > > Am I missing something? Is there any reason for not providing |
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> > > something like RUSTFLAGS? |
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> > > |
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> > > Best regards, |
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> > > Andrew Savchenko |
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> > |
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> > Hi, |
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> > |
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> > I have this in make.conf for quite some time. |
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> > |
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> > RUSTFLAGS="-Ctarget-cpu=native -v" |
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> > |
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> > it just works(tm) as you expect it to. |
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> |
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> Well, it does not, at least for me. Right now I'm building |
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> torbrowser from mozilla overlay and content of RUSTFLAGS from |
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> make.conf doesn't show up in rustc arguments. |
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> |
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That's something about mozbuild, not the variable itself. |
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check about:buildconfig page of torbrowser. |
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RUSTFLAGS show up for me on that page, not 100% sure if they actually get |
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applied. |
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I have no idea how it calls rustc. if it's cargo then to see verbose |
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invocations you need to find where the build system calls it and add "-vv" |
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btw, be careful with -C opt-level=3 for ff or derivatives, it was known to |
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cause segfaults some time ago. |
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for regular packages this variable works fine. |
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> Moreover there is no mention of RUSTFLAGS in either man rustc or |
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> rust/cargo eclasses. |
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because it's a variable used by cargo to call rustc with given params, not by |
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rustc itself. |
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This has nothing to do with eclass, it's cargo setting supposed to be set by |
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user. |
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|
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CARGO-RUSTC(1) page does mention it |
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more details here: |
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https://github.com/rust-lang/cargo/blob/master/src/doc/src/reference/ |
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environment-variables.md |
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> |
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> > I remember earlier rustc/cargo were failing if same options specified |
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> > twice, for example once in toml files and second time via RUSTFLAGS, but |
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> > I can't reproduce anymore. |
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> > Maybe it got smarter and RUSTFLAGS actually override whatever is set in |
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> > toml files. |
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> > |
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> > |
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> > - |
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> > Regards, Georgy |
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> |
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> Best regards, |
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> Andrew Savchenko |
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