add support of vcpkg with msvc toolchain

[lapoigne]

I added the support of vcpkg libraries in proj-sys.
This allow to build proj-sys on windows with msvc without pkg-config.

To use vcpkg libraries on your rust program, you need:

• in .cargo/config file

[target.x86_64-pc-windows-msvc]
linker = "rust-lld.exe"
rustflags = ["-Ctarget-feature=+crt-static"]

• in Cargo.toml file

[package.metadata.vcpkg]
git = "https://github.com/microsoft/vcpkg"
rev = "96a1f9c" # PROJ version 7.2.1 - https://github.com/microsoft/vcpkg/search?q=proj4&type=commits
install = ["proj:x64-windows-static"]

To build, run

cargo install cargo-vcpkg
cargo vcpkg build
cargo build

I'm new to rust, I hope this isn't to ugly in my implementation.

[michaelkirk]

AFAIK none of the main contributors are using windows, so it'd be good to test this setup in CI.

Do you have any experience with using windows containers in GH actions? Would you be willing to add a job to https://github.com/georust/proj/blob/master/.github/workflows/test.yml?

[urschrei]

Hi @lapoigne, apologies for the delay. As @michaelkirk says, we don't have anyone available to locally test this, but we're certainly interested in anything that improves the Windows experience for these crates.

[lapoigne]

I will look closer to add CI for windows platform.

[lapoigne]

I added windows in CI file.
The 32bit platform is commented because we loose precision in floating number and the test fail.
Maybe you just want remove this architecture.
I edited some test because I get some insignificant change in some value like 1450880.2910605008 for 1450880.2910605003

[michaelkirk]

bors try

Sorry to let this sit for so long. Thanks for adding the ci integration, let's try it out.

[michaelkirk]

bors try

[bors]

try

Already running a review

[michaelkirk]

bors r-

[michaelkirk]

bors retry

[michaelkirk]

bors r+

one last try bors.

[michaelkirk]

Bors is crashing, I'm going to follow up with some bors peeps.

update: done here https://forum.bors.tech/t/bors-crashing-resource-not-accessible-by-integration/571/3

update 2: looking into similarly errors reported, it seems like "editing the workflow file" is a common source of crashes between bors and gh

[bors]

try

Build succeeded:

• ci result

[michaelkirk]

We need to constrain the version based on MINIMUM_PROJ_VERSION like we do with pkg_config. Is that possible with vcpkg?

[lapoigne]

I look you to check the version

[lapoigne]

I can't get the library version with vcpkg.
I can walk to library parents directory to read json file of the package if really needed

[michaelkirk]

Sorry for the incredibly long delay (almost a year!).

The nightmare scenario is that someone has an old unsupported version of libproj and this library then gives them weird results because of it. On non-windows platforms we can enforce that this doesn't happen.

I'm not sure how likely this is in practice. Anybody else want to weigh in?

[wlinna]

Using opus-rs as a starting point, I was able to compile proj
rust-av/opus-rs@9f04ec1

Given these assumptions.. :

• You use 64-bit Windows (I tested on Windows 10)
• You have chocolatey installed (a package manager for Windows)
• You have vcpkg installed at C:\src\vcpkg
• You have an environment variable PKG_CONFIG_PATH set to C:\src\vcpkg\installed\x64-windows\lib\pkgconfig
• You have LLVM installed and its path is added to Path environment variable (needed for bindgen I guess?)

These commands should work fine. At least I was able to build my project on Windows :

1. chocolatey install pkgconfiglite (requires elevated privileges)
2. Open PowerShell in C:\src\vcpkg
3. .\vcpkg.exe install proj:x64-windows
4. cargo init
5. cargo add proj
6. cargo build

(NOTE: I don't know whether or not this alone will result in linking with a release build of proj C++-library.)

I'm just thinking that maybe instead of referring to vcpkg directly in build.rs and Cargo configurations, georust/proj could consider requiring pkgconfiglite on Windows just like it requires pkg-config on other platforms (?). Of course the process would have to be documented.

I guess one advantage of this approach would be that it might not actually depend on vcpkg since developers can choose their own method for compiling proj C++-library (or so I believe).

I hope this helps

[michaelkirk]

Hi @wlinna! To clarify — it sounds like you were able to build with the unmodified proj release using the instructions you provided.

Is that right? Or did you have to modify the proj/proj-sys crate in some way?

[wlinna]

That's right, all unmodified :) . Rust, cargo are also installed with default options. All I had to do was to install software and set env variables according to the steps I provided.

…

On Thursday, November 10, 2022, Michael Kirk ***@***.***> wrote: Hi @wlinna <https://github.com/wlinna>! To clarify — it sounds like you were able to build with the unmodified proj release using the instructions you provided. Is that right? Or did you have to modify the proj/proj-sys crate in some way? — Reply to this email directly, view it on GitHub <#79 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AALHXLQZT7FROKWN3KATO4DWHPOW5ANCNFSM4YQYDIOQ> . You are receiving this because you were mentioned.Message ID: ***@***.***>

[kylebarron]

This is amazing! Thanks for the hint about pkgconfiglite @wlinna. I was able to get proj building on CI for Python in geopolars/geopolars#174