Merge pull request #1045 from larskanis/refine-963

Refine #963

lib/ffi/ffi.rb

@@ -32,6 +32,7 @@
 require 'ffi/platform'
 require 'ffi/data_converter'
 require 'ffi/types'
+require 'ffi/library_path'
 require 'ffi/library'
 require 'ffi/errno'
 require 'ffi/abstract_memory'

lib/ffi/library.rb

@@ -33,54 +33,7 @@
 module FFI
   CURRENT_PROCESS = USE_THIS_PROCESS_AS_LIBRARY = FFI.make_shareable(Object.new)
 
-  class LibraryPath < ::Struct.new(:name, :abi_number, :root)
-    PATTERN = /(#{Platform::LIBPREFIX})?(?<name>.*?)(\.|\z)/
-
-    def self.wrap(value)
-      # We allow instances of LibraryPath to pass through transparently:
-      return value if value.is_a?(self)
-
-      # We special case a library named 'c' to be the standard C library:
-      return Library::LIBC if value == 'c'
-
-      # If provided a relative file name we convert it into a library path:
-      if value && File.basename(value) == value
-        if match = PATTERN.match(value)
-          return self.new(match[:name])
-        end
-      end
-
-      # Otherwise, we assume it's a full path to a library:
-      return value
-    end
-
-    def full_name
-      # If the abi_number is given, we format it specifically according to platform rules:
-      if abi_number
-        if Platform.windows?
-          "#{Platform::LIBPREFIX}#{name}-#{abi_number}.#{Platform::LIBSUFFIX}"
-        elsif Platform.mac?
-          "#{Platform::LIBPREFIX}#{name}.#{abi_number}.#{Platform::LIBSUFFIX}"
-        else # Linux? BSD? etc.
-          "#{Platform::LIBPREFIX}#{name}.#{Platform::LIBSUFFIX}.#{abi_number}"
-        end
-      else
-        # Otherwise we just use a generic format:
-        "#{Platform::LIBPREFIX}#{name}.#{Platform::LIBSUFFIX}"
-      end
-    end
-
-    def to_s
-      if root
-        # If the root path is given, we generate the full path:
-        File.join(root, full_name)
-      else
-        full_name
-      end
-    end
-  end
-
-  # @param [#to_s] lib library name
+  # @param [String, FFI::LibraryPath] lib library name or LibraryPath object
   # @return [String] library name formatted for current platform
   # Transform a generic library name to a platform library name
   # @example
@@ -90,9 +43,9 @@ def to_s
   #  # Windows
   #  FFI.map_library_name 'c'     # -> "msvcrt.dll"
   #  FFI.map_library_name 'jpeg'  # -> "jpeg.dll"
-  def self.map_library_name(value)
+  def self.map_library_name(lib)
     # Mangle the library name to reflect the native library naming conventions
-    LibraryPath.wrap(value).to_s
+    LibraryPath.wrap(lib).to_s
   end
 
   # Exception raised when a function is not found in libraries

lib/ffi/library_path.rb

@@ -0,0 +1,109 @@
+#
+# Copyright (C) 2023 Lars Kanis
+#
+# This file is part of ruby-ffi.
+#
+# All rights reserved.
+#
+# Redistribution and use in source and binary forms, with or without
+# modification, are permitted provided that the following conditions are met:
+#
+# * Redistributions of source code must retain the above copyright notice, this
+#   list of conditions and the following disclaimer.
+# * Redistributions in binary form must reproduce the above copyright notice
+#   this list of conditions and the following disclaimer in the documentation
+#   and/or other materials provided with the distribution.
+# * Neither the name of the Ruby FFI project nor the names of its contributors
+#   may be used to endorse or promote products derived from this software
+#   without specific prior written permission.
+#
+# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
+# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+# IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
+# DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE
+# FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+# DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
+# SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
+# CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
+# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+# OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.#
+
+module FFI
+  # Transform a generic library name and ABI number to a platform library name
+  #
+  # Example:
+  #   module LibVips
+  #     extend FFI::Library
+  #     ffi_lib LibraryPath.new("vips", abi_number: 42)
+  #   end
+  #
+  # This translates to the following library file names:
+  #   libvips-42.dll    on Windows
+  #   libvips.so.42     on Linux
+  #   libvips.42.dylib  on Macos
+  #
+  # See https://packaging.ubuntu.com/html/libraries.html for more information about library naming.
+  class LibraryPath
+    attr_reader :name
+    attr_reader :abi_number
+    attr_reader :root
+
+    # Build a new library path
+    #
+    # * <tt>name</tt> :  The name of the library without file prefix or suffix.
+    # * <tt>abi_number</tt> :  The ABI number of the library.
+    # * <tt>root</tt> :  An optional base path prepended to the library name.
+    def initialize(name, abi_number: nil, root: nil)
+      @name = name
+      @abi_number = abi_number
+      @root = root
+    end
+
+    def self.wrap(value)
+      # We allow instances of LibraryPath to pass through transparently:
+      return value if value.is_a?(self)
+
+      # We special case a library named 'c' to be the standard C library:
+      return Library::LIBC if value == 'c'
+
+      # If provided a relative file name we convert it into a library path:
+      if value && File.basename(value) == value
+        return self.new(value)
+      end
+
+      # Otherwise, we assume it's a full path to a library:
+      return value
+    end
+
+    def full_name
+      # If the abi_number is given, we format it specifically according to platform rules:
+      if abi_number
+        if Platform.windows?
+          "#{Platform::LIBPREFIX}#{name}-#{abi_number}.#{Platform::LIBSUFFIX}"
+        elsif Platform.mac?
+          "#{Platform::LIBPREFIX}#{name}.#{abi_number}.#{Platform::LIBSUFFIX}"
+        else # Linux? BSD? etc.
+          "#{Platform::LIBPREFIX}#{name}.#{Platform::LIBSUFFIX}.#{abi_number}"
+        end
+      else
+        # Otherwise we just add prefix and suffix:
+        lib = name
+        # Add library prefix if missing
+        lib = Platform::LIBPREFIX + lib unless lib =~ /^#{Platform::LIBPREFIX}/
+        # Add library extension if missing
+        r = Platform.windows? || Platform.mac? ? "\\.#{Platform::LIBSUFFIX}$" : "\\.so($|\\.[1234567890]+)"
+        lib += ".#{Platform::LIBSUFFIX}" unless lib =~ /#{r}/
+        lib
+      end
+    end
+
+    def to_s
+      if root
+        # If the root path is given, we generate the full path:
+        File.join(root, full_name)
+      else
+        full_name
+      end
+    end
+  end
+end

spec/ffi/ffi_spec.rb

@@ -12,10 +12,24 @@
     let(:prefix) { FFI::Platform::LIBPREFIX }
     let(:suffix) { FFI::Platform::LIBSUFFIX }
 
+    it "should add platform library preffix if not present" do
+      expect(FFI.map_library_name("dummy")).to eq("#{prefix}dummy.#{suffix}")
+    end
+
     it "should add platform library extension if not present" do
       expect(FFI.map_library_name("#{prefix}dummy")).to eq("#{prefix}dummy.#{suffix}")
     end
 
+    it "should'n add platform library extension if already present" do
+      if FFI::Platform.windows?
+        expect(FFI.map_library_name("#{prefix}dummy-5.dll")).to eq("#{prefix}dummy-5.dll")
+      elsif FFI::Platform.mac?
+        expect(FFI.map_library_name("#{prefix}dummy.5.dylib")).to eq("#{prefix}dummy.5.dylib")
+      else # Linux? BSD? etc.
+        expect(FFI.map_library_name("#{prefix}dummy.so.5")).to eq("#{prefix}dummy.so.5")
+      end
+    end
+
     it "should add platform library extension even if lib suffix is present in name" do
       expect(FFI.map_library_name("#{prefix}dummy_with_#{suffix}")).to eq("#{prefix}dummy_with_#{suffix}.#{suffix}")
     end
@@ -25,13 +39,13 @@
     end
 
     it "should return library path with abi version" do
-      expect(FFI.map_library_name(FFI::LibraryPath.new('vips', 42))).to be =~ /#{prefix}vips.*42/
+      expect(FFI.map_library_name(FFI::LibraryPath.new('vips', abi_number: 42))).to be =~ /#{prefix}vips.*42/
     end
 
     it "should return library path with root" do
       root = "/non/existant/root"
 
-      expect(FFI.map_library_name(FFI::LibraryPath.new('vips', 42, root))).to be =~ /#{root}/#{prefix}vips.*42/
+      expect(FFI.map_library_name(FFI::LibraryPath.new('vips', abi_number: 42, root: root))).to be =~ /#{root}/#{prefix}vips.*42/
     end
   end