Add "c_long_size" guard, supplanting "wordsize" and stop using Integer#size

What a "word" is when talking about sizes is confusing because it's a
highly overloaded term. Intel, Microsoft, and GDB are just a few vendors
that have their own definition of what a "word" is. Specs that used the
"wordsize" guard actually were mostly testing for the size of the C
`long` fundamental type, so rename the guard for clarity.

Also, get the size of `long` directly from RbConfig instead of guessing
using Integer#size. Integer#size is not guaranteed to have anything to
do with the `long` type.

3 files changed, 32 insertions, 28 deletions

diff --git a/spec/mspec/lib/mspec/guards/platform.rb b/spec/mspec/lib/mspec/guards/platform.rb
index e87b08a4c1..03c0fca8f5 100644
--- a/spec/mspec/lib/mspec/guards/platform.rb
+++ b/spec/mspec/lib/mspec/guards/platform.rb
@@ -53,23 +53,27 @@ class PlatformGuard < SpecGuard
     end
   end
 
-  WORD_SIZE = 1.size * 8
-
   POINTER_SIZE = begin
     require 'rbconfig/sizeof'
     RbConfig::SIZEOF["void*"] * 8
   rescue LoadError
-    WORD_SIZE
+    [0].pack('j').size
   end
 
-  def self.wordsize?(size)
-    size == WORD_SIZE
+  C_LONG_SIZE = if defined?(RbConfig::SIZEOF[])
+    RbConfig::SIZEOF["long"] * 8
+  else
+    [0].pack('l!').size
   end
 
   def self.pointer_size?(size)
     size == POINTER_SIZE
   end
 
+  def self.c_long_size?(size)
+    size == C_LONG_SIZE
+  end
+
   def initialize(*args)
     if args.last.is_a?(Hash)
       @options, @platforms = args.last, args[0..-2]
@@ -85,10 +89,10 @@ class PlatformGuard < SpecGuard
       case key
       when :os
         match &&= PlatformGuard.os?(*value)
-      when :wordsize
-        match &&= PlatformGuard.wordsize? value
       when :pointer_size
         match &&= PlatformGuard.pointer_size? value
+      when :c_long_size
+        match &&= PlatformGuard::c_long_size? value
       end
     end
     match
diff --git a/spec/mspec/lib/mspec/helpers/numeric.rb b/spec/mspec/lib/mspec/helpers/numeric.rb
index c1ed81a233..46d3d7b182 100644
--- a/spec/mspec/lib/mspec/helpers/numeric.rb
+++ b/spec/mspec/lib/mspec/helpers/numeric.rb
@@ -28,7 +28,7 @@ end
 # specs based on the relationship between values rather than specific
 # values.
 if PlatformGuard.standard? or PlatformGuard.implementation? :topaz
-  if PlatformGuard.wordsize? 32
+  if PlatformGuard.c_long_size? 32
     def fixnum_max
       (2**30) - 1
     end
@@ -36,7 +36,7 @@ if PlatformGuard.standard? or PlatformGuard.implementation? :topaz
     def fixnum_min
       -(2**30)
     end
-  elsif PlatformGuard.wordsize? 64
+  elsif PlatformGuard.c_long_size? 64
     def fixnum_max
       (2**62) - 1
     end
diff --git a/spec/mspec/spec/guards/platform_spec.rb b/spec/mspec/spec/guards/platform_spec.rb
index 88a7ad86f2..bd37432800 100644
--- a/spec/mspec/spec/guards/platform_spec.rb
+++ b/spec/mspec/spec/guards/platform_spec.rb
@@ -81,44 +81,44 @@ RSpec.describe Object, "#platform_is_not" do
   end
 end
 
-RSpec.describe Object, "#platform_is :wordsize => SIZE_SPEC" do
+RSpec.describe Object, "#platform_is :c_long_size => SIZE_SPEC" do
   before :each do
-    @guard = PlatformGuard.new :darwin, :wordsize => 32
+    @guard = PlatformGuard.new :darwin, :c_long_size => 32
     allow(PlatformGuard).to receive(:os?).and_return(true)
     allow(PlatformGuard).to receive(:new).and_return(@guard)
     ScratchPad.clear
   end
 
-  it "yields when #wordsize? returns true" do
-    allow(PlatformGuard).to receive(:wordsize?).and_return(true)
-    platform_is(:wordsize => 32) { ScratchPad.record :yield }
+  it "yields when #c_long_size? returns true" do
+    allow(PlatformGuard).to receive(:c_long_size?).and_return(true)
+    platform_is(:c_long_size => 32) { ScratchPad.record :yield }
     expect(ScratchPad.recorded).to eq(:yield)
   end
 
-  it "doesn not yield when #wordsize? returns false" do
-    allow(PlatformGuard).to receive(:wordsize?).and_return(false)
-    platform_is(:wordsize => 32) { ScratchPad.record :yield }
+  it "doesn not yield when #c_long_size? returns false" do
+    allow(PlatformGuard).to receive(:c_long_size?).and_return(false)
+    platform_is(:c_long_size => 32) { ScratchPad.record :yield }
     expect(ScratchPad.recorded).not_to eq(:yield)
   end
 end
 
-RSpec.describe Object, "#platform_is_not :wordsize => SIZE_SPEC" do
+RSpec.describe Object, "#platform_is_not :c_long_size => SIZE_SPEC" do
   before :each do
-    @guard = PlatformGuard.new :darwin, :wordsize => 32
+    @guard = PlatformGuard.new :darwin, :c_long_size => 32
     allow(PlatformGuard).to receive(:os?).and_return(true)
     allow(PlatformGuard).to receive(:new).and_return(@guard)
     ScratchPad.clear
   end
 
-  it "yields when #wordsize? returns false" do
-    allow(PlatformGuard).to receive(:wordsize?).and_return(false)
-    platform_is_not(:wordsize => 32) { ScratchPad.record :yield }
+  it "yields when #c_long_size? returns false" do
+    allow(PlatformGuard).to receive(:c_long_size?).and_return(false)
+    platform_is_not(:c_long_size => 32) { ScratchPad.record :yield }
     expect(ScratchPad.recorded).to eq(:yield)
   end
 
-  it "doesn not yield when #wordsize? returns true" do
-    allow(PlatformGuard).to receive(:wordsize?).and_return(true)
-    platform_is_not(:wordsize => 32) { ScratchPad.record :yield }
+  it "doesn not yield when #c_long_size? returns true" do
+    allow(PlatformGuard).to receive(:c_long_size?).and_return(true)
+    platform_is_not(:c_long_size => 32) { ScratchPad.record :yield }
     expect(ScratchPad.recorded).not_to eq(:yield)
   end
 end
@@ -184,13 +184,13 @@ RSpec.describe PlatformGuard, ".standard?" do
   end
 end
 
-RSpec.describe PlatformGuard, ".wordsize?" do
+RSpec.describe PlatformGuard, ".c_long_size?" do
   it "returns true when arg is 32 and 1.size is 4" do
-    expect(PlatformGuard.wordsize?(32)).to eq(1.size == 4)
+    expect(PlatformGuard.c_long_size?(32)).to eq(1.size == 4)
   end
 
   it "returns true when arg is 64 and 1.size is 8" do
-    expect(PlatformGuard.wordsize?(64)).to eq(1.size == 8)
+    expect(PlatformGuard.c_long_size?(64)).to eq(1.size == 8)
   end
 end