krun-sys: find libkrun using pkg-config #147
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slp
requested review from
teohhanhui,
alyssarosenzweig,
asahilina and
WhatAmISupposedToPutHere
as code owners
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We should investigate whether we can just use https://docs.rs/system-deps/latest/system_deps/ (as seem from rust-lang/rust-project-goals#108 (comment)) |
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Wonderful, our CI uses Ubuntu, and
We're going to start using |
| println!("cargo::rerun-if-changed=wrapper.h"); | ||
| println!("cargo::rustc-link-lib=krun"); |
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I'm most likely asking out of ignorance here, but https://doc.rust-lang.org/cargo/reference/build-scripts.html#rustc-link-lib says this emits the -l flag to the compiler.
With this gone, where / how does that happen then? Below we only emit -I flags, right?
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bindgen doesn't really need to link against the library, it just needs the headers.
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Uhh... But since this crate is krun-sys (and specifically https://doc.rust-lang.org/cargo/reference/build-scripts.html#-sys-packages and https://doc.rust-lang.org/cargo/reference/manifest.html#the-links-field), I think it's expected that it'll actually link to libkrun...
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But also, I'm confused where the linking to libkrun happens if not here?
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I was also getting very confused by this, because I was seeing the library getting injected at build time. Turns out pkg_config::probe_library("libkrun")?; also injects (by printing to stdout) parameters to the linker. The documentation of pkg-config is sparse, at best.
We need this to be able to switch krun-sys to pkg-config. Signed-off-by: Sergio Lopez <slp@redhat.com>
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crates/krun-sys/Cargo.toml
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| @@ -10,6 +10,7 @@ links = "krun" | |||
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| [build-dependencies] | |||
| bindgen = { version = "0.69.4", default-features = false } | |||
| pkg-config = { version = "0.3" } | |||
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We should be explicit here and not use default features.
This enables the use of non-system-wide installations of libkrun by exporting the right PKG_CONFIG_PATH. Signed-off-by: Sergio Lopez <slp@redhat.com>
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This enables the use of non-system-wide installations of libkrun by exporting the right PKG_CONFIG_PATH.