[GR-10320,GR-14696] Update return types and fix unsigned return values in Truffle::POSIX

PullRequest: truffleruby/135

Author: eregon

.gitignore

@@ -44,6 +44,9 @@ src/main/c/truffleposix/truffleposix.o
 src/main/c/truffleposix/libtruffleposix.so
 src/main/c/truffleposix/libtruffleposix.dylib
 
+spec/truffle/fixtures/libtestnfi.so
+spec/truffle/fixtures/libtestnfi.dylib
+
 test/truffle/cexts/**/Makefile
 test/truffle/cexts/**/*.bc
 test/truffle/cexts/**/*.su

spec/truffle.mspec

@@ -188,6 +188,9 @@ if i = ARGV.index('slow') and ARGV[i-1] == '--excl-tag' and MSpecScript.child_pr
   ]
 
   module Kernel
+    alias_method :mspec_old_system, :system
+    private :mspec_old_system
+
     alias_method :"mspec_old_`", :`
     private :"mspec_old_`"
   end

spec/truffle/fixtures/libtestnfi.c

@@ -0,0 +1,9 @@
+#include <limits.h>
+
+unsigned short max_ushort(void) {
+  return USHRT_MAX;
+}
+
+unsigned int max_uint(void) {
+  return UINT_MAX;
+}

spec/truffle/posix_spec.rb

@@ -0,0 +1,36 @@
+# Copyright (c) 2019 Oracle and/or its affiliates. All rights reserved. This
+# code is released under a tri EPL/GPL/LGPL license. You can use it,
+# redistribute it and/or modify it under the terms of the:
+#
+# Eclipse Public License version 1.0, or
+# GNU General Public License version 2, or
+# GNU Lesser General Public License version 2.1.
+
+require_relative '../ruby/spec_helper'
+
+describe "Trffle::POSIX returns the correct value for an identity function returning" do
+  before :all do
+    src = fixture __FILE__, "libtestnfi.c"
+    lib = src[0...-1] + RbConfig::CONFIG['NATIVE_DLEXT']
+    unless system "cc", "-shared", "-o", lib, src
+      abort "Could not compile libtestnfi"
+    end
+
+    lazy_library = Truffle::POSIX::LazyLibrary.new do
+      Polyglot.eval('nfi', "load '#{lib}'")
+    end
+
+    @libtestnfi = Module.new do
+      Truffle::POSIX.attach_function :max_ushort, [], :ushort, lazy_library, false, :max_ushort, self
+      Truffle::POSIX.attach_function :max_uint, [], :uint, lazy_library, false, :max_uint, self
+    end
+  end
+
+  it "the maximum unsigned short" do
+    @libtestnfi.max_ushort.should == 65535
+  end
+
+  it "the maximum unsigned int" do
+    @libtestnfi.max_uint.should == 4294967295
+  end
+end

src/main/ruby/core/posix.rb

@@ -117,6 +117,9 @@ def self.attach_function_eagerly(native_name, argument_types, return_type,
       string_args.freeze
 
       nfi_return_type = to_nfi_type(return_type)
+      if nfi_return_type.to_s.start_with?('uint')
+        unsigned_return_type = 1 << nfi_return_type[-2..-1].to_i
+      end
 
       bound_func = func.bind("(#{nfi_args_types.join(',')}):#{nfi_return_type}")
 
@@ -151,6 +154,12 @@ def self.attach_function_eagerly(native_name, argument_types, return_type,
           result = Truffle::FFI::Pointer.new(Truffle::Interop.as_pointer(result))
         elsif return_type == :ssize_t
           result = Truffle.invoke_primitive(:integer_lower, result)
+        elsif unsigned_return_type
+          if result >= 0
+            result
+          else
+            result += unsigned_return_type
+          end
         end
 
         result
@@ -181,7 +190,7 @@ def self.attach_function_eagerly(native_name, argument_types, return_type,
   attach_function :fcntl, [:int, :int, :int], :int
   attach_function :truffleposix_flock, [:int, :int], :int, LIBTRUFFLEPOSIX, true
   attach_function :truffleposix_fstat, [:int, :pointer], :int, LIBTRUFFLEPOSIX
-  attach_function :truffleposix_fstat_mode, [:int], :long, LIBTRUFFLEPOSIX
+  attach_function :truffleposix_fstat_mode, [:int], :mode_t, LIBTRUFFLEPOSIX
   attach_function :truffleposix_fstat_size, [:int], :long, LIBTRUFFLEPOSIX
   attach_function :fsync, [:int], :int
   attach_function :ftruncate, [:int, :off_t], :int
@@ -193,7 +202,7 @@ def self.attach_function_eagerly(native_name, argument_types, return_type,
   attach_function :link, [:string, :string], :int
   attach_function :lseek, [:int, :off_t, :int], :off_t
   attach_function :truffleposix_lstat, [:string, :pointer], :int, LIBTRUFFLEPOSIX
-  attach_function :truffleposix_lstat_mode, [:string], :long, LIBTRUFFLEPOSIX
+  attach_function :truffleposix_lstat_mode, [:string], :mode_t, LIBTRUFFLEPOSIX
   attach_function :truffleposix_major, [:dev_t], :uint, LIBTRUFFLEPOSIX
   attach_function :truffleposix_minor, [:dev_t], :uint, LIBTRUFFLEPOSIX
   attach_function :mkdir, [:string, :mode_t], :int
@@ -210,7 +219,7 @@ def self.attach_function_eagerly(native_name, argument_types, return_type,
   attach_function :seekdir, [:pointer, :long], :void
   attach_function :truffleposix_select, [:int, :pointer, :int, :pointer, :int, :pointer, :long], :int, LIBTRUFFLEPOSIX
   attach_function :truffleposix_stat, [:string, :pointer], :int, LIBTRUFFLEPOSIX
-  attach_function :truffleposix_stat_mode, [:string], :long, LIBTRUFFLEPOSIX
+  attach_function :truffleposix_stat_mode, [:string], :mode_t, LIBTRUFFLEPOSIX
   attach_function :truffleposix_stat_size, [:string], :long, LIBTRUFFLEPOSIX
   attach_function :symlink, [:string, :string], :int
   attach_function :telldir, [:pointer], :long