feat: MiniPortile#mkmf_config which supports pkg-config files to configure compiler and linker flags

.github/workflows/ci.yml

@@ -67,5 +67,22 @@ jobs:
       - uses: actions/cache@v3
         with:
           path: examples/ports/archives
-          key: ${{ matrix.platform }}-examples-${{ hashFiles('examples/Rakefile') }}
+          key: examples-${{ hashFiles('examples/Rakefile') }}
+      - run: bundle exec rake test:examples
+
+  fedora: # see https://github.com/flavorjones/mini_portile/issues/118
+    runs-on: ubuntu-latest
+    container:
+      image: fedora:35
+    steps:
+      - run: |
+          dnf group install -y "C Development Tools and Libraries"
+          dnf install -y ruby ruby-devel libyaml-devel git-all patch cmake xz
+      - uses: actions/checkout@v3
+      - uses: actions/cache@v3
+        with:
+          path: examples/ports/archives
+          key: examples-${{ hashFiles('examples/Rakefile') }}
+      - run: bundle install
+      - run: bundle exec rake test:unit
       - run: bundle exec rake test:examples

.gitignore

@@ -3,3 +3,4 @@ Gemfile.lock
 pkg
 ports
 tmp
+mkmf.log

examples/Rakefile

@@ -4,6 +4,7 @@ $: << File.expand_path(File.join(File.dirname(__FILE__), "../lib"))
 require "mini_portile2"
 
 recipes = []
+recipe_hooks = {}
 
 def windows?
   RbConfig::CONFIG['target_os'] =~ /mswin|mingw32/
@@ -119,6 +120,29 @@ zlib.files << {
 
 recipes.push zlib
 
+#
+#  libyaml, using pkgconf for configuration
+#
+yaml = MiniPortile.new("yaml", "0.2.5")
+yaml.files = [{
+                url: "https://github.com/yaml/libyaml/releases/download/0.2.5/yaml-0.2.5.tar.gz",
+                sha256: "c642ae9b75fee120b2d96c712538bd2cf283228d2337df2cf2988e3c02678ef4",
+              }]
+recipes.unshift(yaml)
+recipe_hooks["yaml"] = lambda do |recipe|
+  recipe.mkmf_config(pkg: "yaml-0.1")
+
+  expected = "-L" + File.join(recipe.path, "lib")
+  $LDFLAGS.split.include?(expected) or raise(<<~MSG)
+    assertion failed: LDFLAGS not updated correctly:
+    #{$LDFLAGS}
+    should have included '#{expected}'
+  MSG
+
+  unless have_library("yaml", "yaml_get_version", "yaml.h")
+    raise("could not find libyaml development environment")
+  end
+end
 
 namespace :ports do
   directory "ports"
@@ -135,7 +159,11 @@ namespace :ports do
     desc "Install port #{recipe.name} #{recipe.version}"
     task recipe.name => ["ports"] do |t|
       recipe.cook
-      recipe.activate
+      if hook = recipe_hooks[recipe.name]
+        hook.call(recipe)
+      else
+        recipe.activate
+      end
     end
 
     task :all => recipe.name
@@ -146,7 +174,10 @@ namespace :ports do
     recipes.each do |recipe|
       puts "Artifacts of '#{recipe.name}' in '#{recipe.path}'"
     end
-    puts "LDFLAGS: " + ENV['LDFLAGS'].inspect
+    puts "LIBRARY_PATH: #{ENV['LIBRARY_PATH'].inspect}"
+    puts "LDFLAGS: #{ENV['LDFLAGS'].inspect}"
+    puts "$LDFLAGS: #{$LDFLAGS.inspect}"
+    puts "$CFLAGS: #{$CFLAGS.inspect}"
   end
 end
 

lib/mini_portile2/mini_portile.rb

@@ -76,6 +76,24 @@ def self.target_cpu
     RbConfig::CONFIG['target_cpu']
   end
 
+  def self.native_path(path)
+    path = File.expand_path(path)
+    if File::ALT_SEPARATOR
+      path.tr(File::SEPARATOR, File::ALT_SEPARATOR)
+    else
+      path
+    end
+  end
+
+  def self.posix_path(path)
+    path = File.expand_path(path)
+    if File::ALT_SEPARATOR
+      "/" + path.tr(File::ALT_SEPARATOR, File::SEPARATOR).tr(":", File::SEPARATOR)
+    else
+      path
+    end
+  end
+
   def initialize(name, version, **kwargs)
     @name = name
     @version = version
@@ -240,7 +258,7 @@ def activate
 
     # rely on LDFLAGS when cross-compiling
     if File.exist?(lib_path) && (@host != @original_host)
-      full_path = File.expand_path(lib_path)
+      full_path = native_path(lib_path)
 
       old_value = ENV.fetch("LDFLAGS", "")
 
@@ -250,6 +268,43 @@ def activate
     end
   end
 
+  def mkmf_config(pkg: nil, dir: nil)
+    require "mkmf"
+
+    if pkg
+      dir ||= File.join(path, "lib", "pkgconfig")
+      pcfile = File.join(dir, "#{pkg}.pc")
+      unless File.exist?(pcfile)
+        raise ArgumentError, "pkg-config file '#{pcfile}' does not exist"
+      end
+
+      output "Configuring MakeMakefile for #{File.basename(pcfile)} (in #{File.dirname(pcfile)})\n"
+
+      # on macos, pkg-config will not return --cflags without this
+      ENV["PKG_CONFIG_ALLOW_SYSTEM_CFLAGS"] = "t"
+
+      # append to PKG_CONFIG_PATH as we go, so later pkg-config files can depend on earlier ones
+      ENV["PKG_CONFIG_PATH"] = [ENV["PKG_CONFIG_PATH"], dir].compact.join(File::PATH_SEPARATOR)
+
+      cflags = minimal_pkg_config(pcfile, "cflags")
+      ldflags = minimal_pkg_config(pcfile, "libs", "static")
+    else
+      output "Configuring MakeMakefile for #{@name} #{@version} (from #{path})\n"
+
+      include_path = File.join(path, "include")
+      lib_path = File.join(path, "lib")
+
+      lib_name = name.sub(/\Alib/, "") # TODO: use delete_prefix when we no longer support ruby 2.4
+
+      cflags = "-I#{include_path}" if Dir.exist?(include_path)
+      ldflags = "-L#{lib_path} -l#{lib_name}" if Dir.exist?(lib_path)
+    end
+
+    $CFLAGS << " " << cflags if cflags
+    $CXXFLAGS << " " << cflags if cflags
+    $LDFLAGS << " " << ldflags if ldflags
+  end
+
   def path
     File.expand_path(port_path)
   end
@@ -265,21 +320,11 @@ def make_cmd
   private
 
   def native_path(path)
-    path = File.expand_path(path)
-    if File::ALT_SEPARATOR
-      path.tr(File::SEPARATOR, File::ALT_SEPARATOR)
-    else
-      path
-    end
+    MiniPortile.native_path(path)
   end
 
   def posix_path(path)
-    path = File.expand_path(path)
-    if File::ALT_SEPARATOR
-      "/" + path.tr(File::ALT_SEPARATOR, File::SEPARATOR).tr(":", File::SEPARATOR)
-    else
-      path
-    end
+    MiniPortile.posix_path(path)
   end
 
   def tmp_path
@@ -648,4 +693,29 @@ def with_tempfile(filename, full_path)
     FileUtils.mkdir_p File.dirname(full_path)
     FileUtils.mv temp_file.path, full_path, :force => true
   end
+
+  #
+  #  this minimal version of pkg_config is based on ruby 29dc9378 (2023-01-09)
+  #
+  #  specifically with the fix from b90e56e6 to support multiple pkg-config options, and removing
+  #  code paths that aren't helpful for mini-portile's use case of parsing pc files.
+  #
+  def minimal_pkg_config(pkg, *pcoptions)
+    if pcoptions.empty?
+      raise ArgumentError, "no pkg-config options are given"
+    end
+
+    if ($PKGCONFIG ||=
+        (pkgconfig = MakeMakefile.with_config("pkg-config") {MakeMakefile.config_string("PKG_CONFIG") || "pkg-config"}) &&
+        MakeMakefile.find_executable0(pkgconfig) && pkgconfig)
+      pkgconfig = $PKGCONFIG
+    else
+      raise RuntimeError, "pkg-config is not found"
+    end
+
+    pcoptions = Array(pcoptions).map { |o| "--#{o}" }
+    response = IO.popen([pkgconfig, *pcoptions, pkg], err:[:child, :out], &:read)
+    raise RuntimeError, response unless $?.success?
+    response.strip
+  end
 end

test/assets/pkgconf/libxml2/libxml-2.0.pc

@@ -0,0 +1,13 @@
+prefix=/foo/libxml2/2.11.5
+exec_prefix=${prefix}
+libdir=/foo/libxml2/2.11.5/lib
+includedir=${prefix}/include
+modules=1
+
+Name: libXML
+Version: 2.11.5
+Description: libXML library version2.
+Requires:
+Libs: -L${libdir} -lxml2
+Libs.private: -L/foo/zlib/1.3/lib -lz     -lm  
+Cflags: -I${includedir}/libxml2 

test/assets/pkgconf/libxslt/libexslt.pc

@@ -0,0 +1,13 @@
+prefix=/foo/libxslt/1.1.38
+exec_prefix=${prefix}
+libdir=/foo/libxslt/1.1.38/lib
+includedir=${prefix}/include
+
+
+Name: libexslt
+Version: 0.8.21
+Description: EXSLT Extension library
+Requires: libxml-2.0, libxslt
+Cflags: -I${includedir}
+Libs: -L${libdir} -lexslt
+Libs.private: -lm 

test/assets/pkgconf/libxslt/libxslt.pc

@@ -0,0 +1,13 @@
+prefix=/foo/libxslt/1.1.38
+exec_prefix=${prefix}
+libdir=/foo/libxslt/1.1.38/lib
+includedir=${prefix}/include
+
+
+Name: libxslt
+Version: 1.1.38
+Description: XSLT library version 2.
+Requires: libxml-2.0
+Cflags: -I${includedir}
+Libs: -L${libdir} -lxslt
+Libs.private: -lm