use pkg-config by default, fall back to source build automatically

.travis.yml

@@ -10,37 +10,40 @@ rust:
 os:
   - linux
   - osx
-# by default, test vanilla setup on all three channels
 env:
   global:
-    - PROJ_FEATURES=""
+    - INSTALL_PROJ_FIRST=1 _PROJ_SYS_TEST_EXPECT_BUILD_FROM_SRC=0
 
 # test both features on Linux stable, but only pkg_config on macOS stable
 jobs:
   include:
     - os: linux
-      env: PROJ_FEATURES="--features bundled_proj"
-    - os: linux
-      env: PROJ_FEATURES="--features pkg_config"
+      env: INSTALL_PROJ_FIRST=0 _PROJ_SYS_TEST_EXPECT_BUILD_FROM_SRC=1
     - os: osx
-      env: PROJ_FEATURES="--features pkg_config"
+      env: INSTALL_PROJ_FIRST=0 _PROJ_SYS_TEST_EXPECT_BUILD_FROM_SRC=1
+    # verify we can build from src even if its already installed
+    - os: linux
+      env: INSTALL_PROJ_FIRST=1 PROJ_FEATURES="--features bundled_proj" _PROJ_SYS_TEST_EXPECT_BUILD_FROM_SRC=1
     - os: osx
-      env: PROJ_FEATURES="--features bundled_proj"
+      env: INSTALL_PROJ_FIRST=1 PROJ_FEATURES="--features bundled_proj" _PROJ_SYS_TEST_EXPECT_BUILD_FROM_SRC=1
 
 before_install:
   - |
-    if [ "$TRAVIS_OS_NAME" == "linux" ] && [ "$PROJ_FEATURES" != "--features bundled_proj" ]; then
-      sudo apt-get update
-      sudo apt-get -y install pkg-config
-      wget https://download.osgeo.org/proj/proj-7.1.0.tar.gz
-      tar -xzvf proj-7.1.0.tar.gz
-      pushd proj-7.1.0 && ./configure --prefix=/usr && make && sudo make install && popd
-    fi
-  - |
-    if [ "$TRAVIS_OS_NAME" == "osx" ] && [ "$PROJ_FEATURES" != "--features bundled_proj" ]; then
-      brew update
-      brew upgrade pkg-config
-      brew upgrade proj
+    if [[ $INSTALL_PROJ_FIRST == "1" ]]; then
+      case $TRAVIS_OS_NAME in
+      "linux")
+        sudo apt-get update
+        sudo apt-get -y install pkg-config
+        wget https://download.osgeo.org/proj/proj-7.1.0.tar.gz
+        tar -xzvf proj-7.1.0.tar.gz
+        pushd proj-7.1.0 && ./configure --prefix=/usr && make && sudo make install && popd
+        ;;
+      "osx")
+        brew update
+        brew upgrade pkg-config
+        brew upgrade proj
+        ;;
+      esac
     fi
 
 script:

Cargo.toml

@@ -21,8 +21,9 @@ tar = "0.4.26"
 
 [features]
 nobuild = []
-pkg_config = []
 bundled_proj = []
+# `pkg_config` feature is deprecated and does nothing
+pkg_config = []
 
 [package.metadata.docs.rs]
 features = [ "nobuild" ] # This feature will be enabled during the docs.rs build

README.md

@@ -1,26 +1,30 @@
 [![Build Status](https://travis-ci.org/georust/proj-sys.svg?branch=master)](https://travis-ci.org/georust/proj-sys)
 
 # Low-level bindings for PROJ v7.1.x
-**This is a [`*-sys`](https://doc.rust-lang.org/cargo/reference/build-scripts.html#a-sys-packages) crate; you shouldn't use its API directly.** The [`proj`](https://github.com/georust/proj) crate is designed for general use.
 
-A guide to the functions can be found here: https://proj.org/development/reference/functions.html. Run `cargo doc (optionally --open)` to generate the crate documentation.
+**This is a
+[`*-sys`](https://doc.rust-lang.org/cargo/reference/build-scripts.html#-sys-packages)
+crate; you shouldn't use its API directly.** See the
+[`proj`](https://github.com/georust/proj) crate for general use.
 
-## Requirements
+A guide to the functions can be found here:
+https://proj.org/development/reference/functions.html. 
 
-By default, `libproj` (via `PROJ v7.1.x`) must be present on your system. While this crate may be backwards-compatible with older PROJ 7 and PROJ 6 versions, this is neither tested or supported.
+By default, the crate will search for an existing `libproj` (via `PROJ v7.1.x`)
+installation on your system using
+[pkg-config](https://www.freedesktop.org/wiki/Software/pkg-config/). 
 
-## Optional Features
-Enable these in your `Cargo.toml` like so:
+If an acceptable installation is not found, proj-sys will attempt to build
+libproj from source bundled in the crate.
 
-`proj-sys = { version = "0.18.1", features = ["bundled_proj"] }`  
-`proj-sys = { version = "0.18.1", features = ["pkg_config"] }`  
+## Features
 
-Note that these features are **mutually exclusive**.
-
-1. `bundled_proj` (Linux and macOS targets):
-    - allow the crate to internally build and depend on a bundled `libproj`. Note that SQLite3 and `libtiff` must be present on your system if you wish to use this feature, and that it builds `libproj` **without** its native network functionality; you will have to implement your own set of callbacks if you wish to make use of them (see the [`proj`](https://crates.io/crates/proj) crate for an example).
-2. `pkg_config` (Linux and macOS targets)
-    - uses [`pkg-config`](https://en.wikipedia.org/wiki/Pkg-config) to add search paths to the build script. Requires `pkg-config` to be installed (available on Homebrew, Macports, apt etc.)
+`bundled_proj` - forces building libproj from source even if an acceptable
+version could be found on your system.  Note that SQLite3 and `libtiff` must be
+present on your system if you wish to use this feature, and that it builds
+`libproj` **without** its native network functionality; you will have to
+implement your own set of callbacks if you wish to make use of them (see the
+[`proj`](https://crates.io/crates/proj) crate for an example).
 
 ## License
 

build.rs

@@ -1,103 +1,53 @@
 use bindgen;
-#[cfg(all(
-    not(feature = "pkg_config"),
-    feature = "bundled_proj",
-    not(feature = "nobuild")
-))]
 use cmake;
-#[cfg(all(
-    not(feature = "pkg_config"),
-    feature = "bundled_proj",
-    not(feature = "nobuild")
-))]
 use flate2::read::GzDecoder;
-#[cfg(all(
-    not(feature = "pkg_config"),
-    feature = "bundled_proj",
-    not(feature = "nobuild")
-))]
 use std::fs::File;
 
-#[cfg(all(
-    feature = "pkg_config",
-    not(feature = "bundled_proj"),
-    not(feature = "nobuild")
-))]
 use pkg_config;
 use std::env;
 use std::path::PathBuf;
-#[cfg(all(
-    not(feature = "pkg_config"),
-    feature = "bundled_proj",
-    not(feature = "nobuild")
-))]
 use tar::Archive;
 
-#[cfg(all(
-    feature = "pkg_config",
-    not(feature = "bundled_proj"),
-    not(feature = "nobuild")
-))]
 const MINIMUM_PROJ_VERSION: &str = "7.1.0";
 
 #[cfg(feature = "nobuild")]
 fn main() {} // Skip the build script on docs.rs
 
-// We sometimes need additional search paths, which we get using pkg-config
-#[cfg(all(
-    feature = "pkg_config",
-    not(feature = "nobuild"),
-    not(feature = "bundled_proj")
-))]
-fn main() {
-    let pk = pkg_config::Config::new()
+#[cfg(not(feature = "nobuild"))]
+fn main() -> Result<(), Box<dyn std::error::Error>> {
+    let include_path = if cfg!(feature = "bundled_proj") {
+        eprintln!("feature flags specified source build");
+        build_from_source()?
+    } else {
+        pkg_config::Config::new()
         .atleast_version(MINIMUM_PROJ_VERSION)
         .probe("proj")
-        .expect(&format!(
-            "Your PROJ version may be too old. You need at least version {}",
-            MINIMUM_PROJ_VERSION
-        ));
-    // Tell cargo to tell rustc to link the system proj
-    // shared library.
-    println!("cargo:rustc-link-search=native={:?}", pk.link_paths[0]);
-    println!("cargo:rustc-link-lib=proj");
-    let include_path = pk.include_paths[0].to_string_lossy();
-
-    // The bindgen::Builder is the main entry point
-    // to bindgen, and lets you build up options for
-    // the resulting bindings.
-    let bindings = bindgen::Builder::default()
-        .clang_arg(format!("-I{}", include_path))
-        .trust_clang_mangling(false)
-        .blacklist_type("max_align_t")
-        // The input header we would like to generate
-        // bindings for.
-        .header("wrapper.h")
-        // Finish the builder and generate the bindings.
-        .generate()
-        // Unwrap the Result and panic on failure.
-        .expect("Unable to generate bindings");
+        .and_then(|pk| {
+            eprintln!("found acceptable libproj already installed at: {:?}", pk.link_paths[0]);
+            if let Ok(val) = &env::var("_PROJ_SYS_TEST_EXPECT_BUILD_FROM_SRC") {
+                if val != "0" {
+                    panic!("for testing purposes: existing package was found, but should not have been");
+                }
+            }
 
-    // Write the bindings to the $OUT_DIR/bindings.rs file.
-    let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
-    bindings
-        .write_to_file(out_path.join("bindings.rs"))
-        .expect("Couldn't write bindings!");
-}
+            // Tell cargo to tell rustc to link the system proj
+            // shared library.
+            println!("cargo:rustc-link-search=native={:?}", pk.link_paths[0]);
+            println!("cargo:rustc-link-lib=proj");
 
-// Vanilla
-#[cfg(all(
-    not(feature = "pkg_config"),
-    not(feature = "nobuild"),
-    not(feature = "bundled_proj")
-))]
-fn main() {
-    println!("cargo:rustc-link-lib=proj");
+            Ok(pk.include_paths[0].clone())
+        })
+        .or_else(|err| {
+            eprintln!("pkg-config unable to find existing libproj installation: {}", err);
+            build_from_source()
+        })?
+    };
 
     // The bindgen::Builder is the main entry point
     // to bindgen, and lets you build up options for
     // the resulting bindings.
     let bindings = bindgen::Builder::default()
+        .clang_arg(format!("-I{}", include_path.to_string_lossy()))
         .trust_clang_mangling(false)
         .blacklist_type("max_align_t")
         // The input header we would like to generate
@@ -110,25 +60,29 @@ fn main() {
 
     // Write the bindings to the $OUT_DIR/bindings.rs file.
     let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
-    bindings
-        .write_to_file(out_path.join("bindings.rs"))
-        .expect("Couldn't write bindings!");
+    bindings.write_to_file(out_path.join("bindings.rs"))?;
+
+    Ok(())
 }
 
-#[cfg(all(
-    not(feature = "pkg-config"),
-    not(feature = "nobuild"),
-    feature = "bundled_proj"
-))]
-fn main() {
-    // Build PROJ from the included tar
+// returns the path of "inlude" for the built proj
+fn build_from_source() -> Result<std::path::PathBuf, Box<dyn std::error::Error>> {
+    eprintln!("building libproj from source");
+    if let Ok(val) = &env::var("_PROJ_SYS_TEST_EXPECT_BUILD_FROM_SRC") {
+        if val == "0" {
+            panic!(
+                "for testing purposes: package was building from source but should not have been"
+            );
+        }
+    }
+
     // NOTE: The PROJ build expects Sqlite3 to be present on the system.
     let path = "PROJSRC/proj-7.1.0.tar.gz";
     let out_path = PathBuf::from(env::var("OUT_DIR").unwrap());
-    let tar_gz = File::open(path).expect("Couldn't open PROJ source tar");
+    let tar_gz = File::open(path)?;
     let tar = GzDecoder::new(tar_gz);
     let mut archive = Archive::new(tar);
-    archive.unpack("PROJSRC/proj").expect("Couldn't unpack tar");
+    archive.unpack("PROJSRC/proj")?;
     let mut config = cmake::Config::new("PROJSRC/proj/proj-7.1.0");
     config.define("BUILD_SHARED_LIBS", "OFF");
     config.define("BUILD_TESTING", "OFF");
@@ -168,12 +122,5 @@ fn main() {
         println!("cargo:warning=proj-sys: Not configuring an explicit C++ standard library on this target.");
     }
 
-    bindgen::builder()
-        .header(proj.join("include").join("proj.h").to_str().unwrap())
-        .trust_clang_mangling(false)
-        .blacklist_type("max_align_t")
-        .generate()
-        .expect("Unable to generate bindings")
-        .write_to_file(out_path.join("bindings.rs"))
-        .expect("Couldn't write bindings!");
+    Ok(proj.join("include"))
 }

src/lib.rs

@@ -3,36 +3,30 @@
 #![allow(non_snake_case)]
 #![doc(html_logo_url = "https://raw.githubusercontent.com/georust/meta/master/logo/logo.png")]
 //! # Low-level bindings for PROJ v7.1.x
-//! **This is a [`*-sys`](https://doc.rust-lang.org/cargo/reference/build-scripts.html#a-sys-packages) crate; you shouldn't use its API directly.** The [`proj`](https://github.com/georust/proj) crate is designed for general use.
-//! 
-//! A guide to the functions can be found on [proj.org](https://proj.org/development/reference/functions.html). Run `cargo doc (optionally --open)` to generate the crate documentation.
-//! 
-//! ## Requirements
-//! 
-//! By default, `libproj` (via `PROJ v7.1.x`) must be present on your system. While this crate may be backwards-compatible with older PROJ 7 and PROJ 6 versions, this is neither tested or supported.
-//! 
-//! ## Optional Features
-//! Enable these in your `Cargo.toml` like so:
-//! 
-//! `proj-sys = { version = "0.18.2", features = ["bundled_proj"] }`  
-//! `proj-sys = { version = "0.18.2", features = ["pkg_config"] }`  
-//! 
-//! Note that these features are **mutually exclusive**.
-//! 
-//! 1. `bundled_proj` (Linux and macOS targets):
-//!     - allow the crate to internally build and depend on a bundled `libproj`. Note that SQLite3 and `libtiff` must be present on your system if you wish to use this feature, and that it builds `libproj` **without** its native network functionality; you will have to implement your own set of callbacks if you wish to make use of them (see the [`proj`](https://crates.io/crates/proj) crate for an example).
-//! 2. `pkg_config` (Linux and macOS targets)
-//!     - uses [`pkg-config`](https://en.wikipedia.org/wiki/Pkg-config) to add search paths to the build script. Requires `pkg-config` to be installed (available on Homebrew, Macports, apt etc.)
-//! 
-//! ## License
-//! 
-//! Licensed under either of
-//! 
-//!  * Apache License, Version 2.0 ([LICENSE-APACHE](LICENSE-APACHE) or http://www.apache.org/licenses/LICENSE-2.0)
-//!  * MIT license ([LICENSE-MIT](LICENSE-MIT) or http://opensource.org/licenses/MIT)
-//! 
-//! at your option.
-
+//!
+//! **This is a
+//! [`*-sys`](https://doc.rust-lang.org/cargo/reference/build-scripts.html#-sys-packages)
+//! crate; you shouldn't use its API directly.** See the
+//! [`proj`](https://github.com/georust/proj) crate for general use.
+//!
+//! A guide to the functions can be found here:
+//! https://proj.org/development/reference/functions.html.
+//!
+//! By default, the crate will search for an existing `libproj` (via `PROJ v7.1.x`)
+//! installation on your system using
+//! [pkg-config](https://www.freedesktop.org/wiki/Software/pkg-config/).
+//!
+//! If an acceptable installation is not found, proj-sys will attempt to build
+//! libproj from source bundled in the crate.
+//!
+//! ## Features
+//!
+//! `bundled_proj` - forces building libproj from source even if an acceptable
+//! version could be found on your system.  Note that SQLite3 and `libtiff` must be
+//! present on your system if you wish to use this feature, and that it builds
+//! `libproj` **without** its native network functionality; you will have to
+//! implement your own set of callbacks if you wish to make use of them (see the
+//! [`proj`](https://crates.io/crates/proj) crate for an example).
 
 #[cfg(not(feature = "nobuild"))]
 include!(concat!(env!("OUT_DIR"), "/bindings.rs"));