support windows mingw64 gnu

Cargo.toml

@@ -20,9 +20,12 @@ name = "libxml"
 [dependencies]
 libc = "0.2"
 
-[target.'cfg(windows)'.build-dependencies]
+[target.'cfg(all(target_family = "windows", target_env = "msvc"))'.build-dependencies]
 vcpkg = "0.2"
 
+[target.'cfg(all(target_family = "windows", target_env = "gnu"))'.build-dependencies]
+pkg-config = "0.3.2"
+
 [target.'cfg(macos)'.build-dependencies]
 pkg-config = "0.3.2"
 

README.md

@@ -43,6 +43,12 @@ $ pkg install libxml2 pkgconf
 
 ### Windows
 
+#### gnu
+
+On mingw64 environment you'd install libxml2 with `pacman -S mingw64/mingw-w64-x86_64-libxml2`.
+
+#### msvc
+
 [Community contributed](https://github.com/KWARC/rust-libxml/issues/81#issuecomment-760364976):
 
 * manually install builds tools c++ and english language by visiting [BuildTools](https://visualstudio.microsoft.com/fr/thank-you-downloading-visual-studio/?sku=BuildTools&rel=16)

build.rs

@@ -59,6 +59,11 @@ mod pkg_config_dep {
 #[cfg(target_family = "windows")]
 mod vcpkg_dep {
   pub fn find() -> bool {
+    #[cfg(target_env = "gnu")]
+    if pkg_config::find_library("libxml-2.0").is_ok() {
+      return true;
+    }
+    #[cfg(target_env = "msvc")]
     if vcpkg::find_package("libxml2").is_ok() {
       return true;
     }