Add support for static linking

pineappl_applgrid/Cargo.toml

@@ -22,3 +22,6 @@ cxx = "1.0.65"
 cc = "1.0.49"
 cxx-build = "1.0.65"
 pkg-config = "0.3.26"
+
+[features]
+static = []

pineappl_applgrid/build.rs

@@ -1,6 +1,7 @@
 #![allow(missing_docs)]
 
 use cc::Build;
+use pkg_config::Config;
 use std::env;
 use std::path::Path;
 use std::process::Command;
@@ -59,11 +60,26 @@ fn main() {
     )
     .unwrap();
 
+    let link_modifier = if cfg!(feature = "static") {
+        // for some reason `libz.a` isn't found, although `libz.so` is
+        for link_path in Config::new().probe("zlib").unwrap().link_paths {
+            println!("cargo:rustc-link-search={}", link_path.to_str().unwrap());
+        }
+
+        "static="
+    } else {
+        ""
+    };
+
     for lib in libs
         .split_whitespace()
         .filter_map(|token| token.strip_prefix("-l"))
     {
-        println!("cargo:rustc-link-lib={lib}");
+        match lib {
+            // we can't link gfortran statically - to avoid it compile APPLgrid without HOPPET
+            "gfortran" => println!("cargo:rustc-link-lib={lib}"),
+            _ => println!("cargo:rustc-link-lib={link_modifier}{lib}"),
+        }
     }
 
     Build::new()
@@ -79,17 +95,14 @@ fn main() {
 
     println!("cargo:rerun-if-env-changed=APPL_IGRID_DIR");
 
-    let lhapdf = pkg_config::Config::new()
-        .atleast_version("6")
-        .probe("lhapdf")
-        .unwrap();
+    let lhapdf = Config::new().atleast_version("6").probe("lhapdf").unwrap();
 
     for lib_path in lhapdf.link_paths {
         println!("cargo:rustc-link-search={}", lib_path.to_str().unwrap());
     }
 
     for lib in lhapdf.libs {
-        println!("cargo:rustc-link-lib={lib}");
+        println!("cargo:rustc-link-lib={link_modifier}{lib}");
     }
 
     cxx_build::bridge("src/lib.rs")

pineappl_cli/Cargo.toml

@@ -56,3 +56,4 @@ applgrid = ["dep:cxx", "dep:pineappl_applgrid"]
 evolve = ["dep:base64", "dep:either", "dep:tar", "dep:lz4_flex", "dep:ndarray-npy", "dep:serde", "dep:serde_yaml"]
 fastnlo = ["dep:pineappl_fastnlo"]
 fktable = ["dep:flate2",  "dep:tar"]
+static = ["lhapdf/static", "pineappl_applgrid?/static", "pineappl_fastnlo?/static"]

pineappl_fastnlo/Cargo.toml

@@ -21,3 +21,6 @@ thiserror = "1.0.30"
 
 [build-dependencies]
 cxx-build = { version = "1.0.65" }
+
+[features]
+static = []

pineappl_fastnlo/build.rs

@@ -23,7 +23,13 @@ fn main() {
     )
     .unwrap();
 
-    println!("cargo:rustc-link-lib=fastnlotoolkit");
+    let link_modifier = if cfg!(feature = "static") {
+        "static="
+    } else {
+        ""
+    };
+
+    println!("cargo:rustc-link-lib={link_modifier}fastnlotoolkit");
 
     cxx_build::bridge("src/lib.rs")
         .file("src/fastnlo.cpp")