On Windows, try to infer HDF5 libdir from PATH

Author: aldanor

appveyor.yml

@@ -7,27 +7,22 @@ matrix:
 skip_tags: true
 build: false
 
-init:
-- ps: iex ((new-object net.webclient).DownloadString('https://raw.githubusercontent.com/appveyor/ci/master/scripts/enable-rdp.ps1'))
-
 environment:
   TARGET: x86_64-pc-windows-msvc
-  HDF5_ROOT: "C:\\Program Files\\HDF_Group\\HDF5\\1.8.16"
+  HDF5_BINDIR: "C:\\Program Files\\HDF_Group\\HDF5\\1.8.16\\bin"
   matrix:
     - CHANNEL: 1.8.0
     - CHANNEL: beta
     - CHANNEL: nightly
 install:
   - ps: Start-FileDownload "https://static.rust-lang.org/dist/rust-${env:CHANNEL}-${env:TARGET}.msi"
   - ps: Start-Process -FilePath msiexec -ArgumentList /i, rust-${env:CHANNEL}-${env:TARGET}.msi, INSTALLDIR="C:\Rust", /quiet -Wait
-  - set PATH=%PATH%;C:\Rust\bin
   - rustc -vV
   - cargo -vV
   - ps: Invoke-WebRequest "http://www.hdfgroup.org/ftp/HDF5/current/bin/windows/extra/hdf5-1.8.16-win64-vs2015-shared.zip" -OutFile hdf5.zip
   - 7z x hdf5.zip -y
   - ps: Start-Process -FilePath msiexec -ArgumentList /i, "hdf5\HDF5-1.8.16-win64.msi", /quiet -Wait
-  - set PATH=%PATH%;%HDF5_ROOT%\bin
-  - set HDF5_LIBDIR=%HDF5_ROOT%\lib
+  - set PATH=%PATH%;C:\Rust\bin;%HDF5_BINDIR%
 
 test_script:
   - cd %APPVEYOR_BUILD_FOLDER%\libhdf5-lib

libhdf5-lib/build.rs

@@ -1,6 +1,63 @@
 extern crate pkg_config;
 
 use std::env;
+use std::fs;
+use std::path::PathBuf;
+
+#[cfg(target_env = "msvc")]
+const IS_MSVC: bool = true;
+#[cfg(not(target_env = "msvc"))]
+const IS_MSVC: bool = false;
+
+#[cfg(target_os = "windows")]
+const IS_WINDOWS: bool = true;
+#[cfg(not(target_os = "windows"))]
+const IS_WINDOWS: bool = false;
+
+macro_rules! ok_or_continue {
+    ($r:expr) => ( match $r { Err(_) => continue, Ok(ok) => ok } )
+}
+
+macro_rules! some_or_continue {
+    ($r:expr) => ( match $r { None => continue, Some(some) => some } )
+}
+
+fn libdir_from_path() -> Option<String> {
+    if !IS_WINDOWS || env::var("HDF5_LIBDIR").is_ok() {
+        return None;
+    }
+    if let Ok(path) = env::var("PATH") {
+        for path in path.split(";") {
+            let dir = PathBuf::from(path);
+            let dirname = some_or_continue!(dir.file_name());
+            if dirname.to_str() != Some("bin") {
+                continue;
+            }
+            let entries = ok_or_continue!(fs::read_dir(&dir));
+            for entry in entries {
+                let entry = ok_or_continue!(entry);
+                let filename = entry.file_name();
+                if filename.to_str() != Some("hdf5.dll") {
+                    continue;
+                }
+                let meta = ok_or_continue!(entry.metadata());
+                if !meta.is_file() {
+                    continue;
+                }
+                if !IS_MSVC {
+                    return Some(path.into());
+                }
+                let parent = some_or_continue!(dir.parent());
+                let libdir = parent.join("lib");
+                if let Some(libdir) = libdir.to_str() {
+                    return Some(libdir.into());
+                }
+            }
+        }
+    }
+    None
+}
+
 
 fn find_hdf5_libs() -> (Vec<String>, Vec<String>) {
     let (mut libs, mut dirs) = (vec![], vec![]);
@@ -11,11 +68,14 @@ fn find_hdf5_libs() -> (Vec<String>, Vec<String>) {
     if let Ok(libdir) = env::var("HDF5_LIBDIR") {
         dirs.push(libdir);
     }
+    if let Some(libdir) = libdir_from_path() {
+        dirs.push(libdir);
+    }
 
     if let Ok(library) = pkg_config::Config::new().find("hdf5") {
         if dirs.is_empty() {
             for dir in library.link_paths.iter() {
-                dirs.push(dir.to_str().unwrap().to_owned());
+                dirs.push(dir.to_str().unwrap().into());
             }
         }
         if libs.is_empty() {
@@ -26,7 +86,7 @@ fn find_hdf5_libs() -> (Vec<String>, Vec<String>) {
     }
 
     if libs.is_empty() {
-        libs.push("hdf5".to_owned());
+        libs.push("hdf5".into());
     }
 
     (libs, dirs)