Use semver-compatible compiler version comparisons

Fixes #154

Author: Lawson Kurtz

ext/libv8/compiler/apple_llvm.rb

@@ -2,17 +2,18 @@ module Libv8
   module Compiler
     class AppleLLVM < Clang
       LLVM_VERSION_REGEXP = /Apple LLVM version (\d+\.\d+(\.\d+)*) \(/i
+      REQUIRED_VERSION = '4.3'
 
       def name
         'Apple LLVM'
       end
 
-      def compatible?
-        version >= '4.3' unless version.nil?
-      end
-
       private
 
+      def required_version
+        REQUIRED_VERSION
+      end
+
       def version_regexp
         LLVM_VERSION_REGEXP
       end

ext/libv8/compiler/clang.rb

@@ -2,17 +2,18 @@ module Libv8
   module Compiler
     class Clang < GenericCompiler
       CLANG_VERSION_REGEXP = /clang version (\d+\.\d+(\.\d+)*) \(/i
+      REQUIRED_VERSION = '3.1'
 
       def name
         'clang'
       end
 
-      def compatible?
-        version >= '3.1' unless version.nil?
-      end
-
       private
 
+      def required_version
+        REQUIRED_VERSION
+      end
+
       def version_regexp
         CLANG_VERSION_REGEXP
       end

ext/libv8/compiler/gcc.rb

@@ -2,17 +2,18 @@ module Libv8
   module Compiler
     class GCC < GenericCompiler
       GCC_VERSION_REGEXP = /gcc version (\d+\.\d+(\.\d+)*)/i
+      REQUIRED_VERSION = '4.7'
 
       def name
         'GCC'
       end
 
-      def compatible?
-        version > '4.7' unless version.nil?
-      end
-
       private
 
+      def required_version
+        REQUIRED_VERSION
+      end
+
       def version_regexp
         GCC_VERSION_REGEXP
       end

ext/libv8/compiler/generic_compiler.rb

@@ -27,7 +27,9 @@ def target
       end
 
       def compatible?
-        false
+        return false unless required_version && !version.nil?
+
+        (string_to_semver(version) <=> string_to_semver(required_version)) > -1
       end
 
       def call(*arguments)
@@ -51,6 +53,14 @@ def version_regexp
       def target_regexp
         GENERIC_TARGET_REGEXP
       end
+
+      def required_version
+        nil
+      end
+
+      def string_to_semver(version)
+        version.split('.').map(&:to_i)
+      end
     end
   end
 end

spec/compiler/apple_llvm_spec.rb

@@ -13,18 +13,25 @@ module Libv8::Compiler
 
     describe '#version' do
       it 'returns the version of the compiler' do
-        stub_as_available 'c++', :apple_llvm, '5.1'
-        expect(subject.version).to eq '5.1'
+        stub_as_available 'c++', :apple_llvm, '4.20'
+        expect(subject.version).to eq '4.20'
       end
     end
 
     describe '#compatible?' do
       context 'when Apple LLVM\'s version is >= 4.3' do
         it 'returns true' do
-          stub_as_available 'c++', :apple_llvm, '5.1'
+          stub_as_available 'c++', :apple_llvm, '4.20'
           expect(subject).to be_compatible
         end
       end
+
+      context 'when Apple LLVM\'s version is < 4.3' do
+        it 'returns false' do
+          stub_as_available 'c++', :apple_llvm, '4.2'
+          expect(subject).to_not be_compatible
+        end
+      end
     end
   end
 end

spec/compiler/clang_spec.rb

@@ -25,6 +25,13 @@ module Libv8::Compiler
           expect(subject).to be_compatible
         end
       end
+
+      context 'when clang\'s version is < 3.1' do
+        it 'returns false' do
+          stub_as_available 'c++', :clang, '3.0.9'
+          expect(subject).to_not be_compatible
+        end
+      end
     end
   end
 end

spec/compiler_spec.rb

@@ -21,7 +21,7 @@ module Libv8
       end
 
       it 'recognises correctly Apple\'s LLVM' do
-        stub_as_available 'c++', :apple_llvm, '5.1'
+        stub_as_available 'c++', :apple_llvm, '4.20'
         expect(Compiler.type_of('c++').new('c++')).to be_a Compiler::AppleLLVM
       end
     end

spec/support/compiler_helpers.rb

@@ -5,11 +5,13 @@ module CompilerHelpers
       "4.9.0" => %Q{Using built-in specs.\nCOLLECT_GCC=c++\nCOLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-unknown-linux-gnu/4.9.0/lto-wrapper\nTarget: x86_64-unknown-linux-gnu\nConfigured with: /build/gcc-multilib/src/gcc-4.9-20140604/configure --prefix=/usr --libdir=/usr/lib --libexecdir=/usr/lib --mandir=/usr/share/man --infodir=/usr/share/info --with-bugurl=https://bugs.archlinux.org/ --enable-languages=c,c++,ada,fortran,go,lto,objc,obj-c++ --enable-shared --enable-threads=posix --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-clocale=gnu --disable-libstdcxx-pch --disable-libssp --enable-gnu-unique-object --enable-linker-build-id --enable-cloog-backend=isl --disable-cloog-version-check --enable-lto --enable-plugin --enable-install-libiberty --with-linker-hash-style=gnu --enable-multilib --disable-werror --enable-checking=release\nThread model: posix\ngcc version 4.9.0 20140604 (prerelease) (GCC)\n}
     },
     :clang => {
+      "3.0.9" => %Q{clang version 3.0.9 (tags/RELEASE_34/dot1-final)\nTarget: x86_64-unknown-linux-gnu\nThread model: posix\nFound candidate GCC installation: /usr/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.9.0\nFound candidate GCC installation: /usr/bin/../lib64/gcc/x86_64-unknown-linux-gnu/4.9.0\nFound candidate GCC installation: /usr/lib/gcc/x86_64-unknown-linux-gnu/4.9.0\nFound candidate GCC installation: /usr/lib64/gcc/x86_64-unknown-linux-gnu/4.9.0\nSelected GCC installation: /usr/bin/../lib64/gcc/x86_64-unknown-linux-gnu/4.9.0\n},
       "3.3-freebsd" => %Q{FreeBSD clang version 3.3 (tags/RELEASE_33/final 183502) 20130610\nTarget: i386-unknown-freebsd9.2\nThread model: posix},
       "3.4.1" => %Q{clang version 3.4.1 (tags/RELEASE_34/dot1-final)\nTarget: x86_64-unknown-linux-gnu\nThread model: posix\nFound candidate GCC installation: /usr/bin/../lib/gcc/x86_64-unknown-linux-gnu/4.9.0\nFound candidate GCC installation: /usr/bin/../lib64/gcc/x86_64-unknown-linux-gnu/4.9.0\nFound candidate GCC installation: /usr/lib/gcc/x86_64-unknown-linux-gnu/4.9.0\nFound candidate GCC installation: /usr/lib64/gcc/x86_64-unknown-linux-gnu/4.9.0\nSelected GCC installation: /usr/bin/../lib64/gcc/x86_64-unknown-linux-gnu/4.9.0\n},
     },
     :apple_llvm => {
-      '5.1' => %Q{Configured with: --prefix=/Applications/Xcode.app/Contents/Developer//usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/c++/4.2.1\nApple LLVM version 5.1 (clang-503.0.38) (based on LLVM 3.4svn)\nTarget: x86_64-apple-darwin14.0.0\nThread model: posix\n}
+      '4.20' => %Q{Configured with: --prefix=/Applications/Xcode.app/Contents/Developer//usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/c++/4.2.1\nApple LLVM version 4.20 (clang-503.0.38) (based on LLVM 3.4svn)\nTarget: x86_64-apple-darwin14.0.0\nThread model: posix\n},
+      '4.2' => %Q{Configured with: --prefix=/Applications/Xcode.app/Contents/Developer//usr --with-gxx-include-dir=/Applications/Xcode.app/Contents/Developer/Platforms/MacOSX.platform/Developer/SDKs/MacOSX10.9.sdk/usr/include/c++/4.2.1\nApple LLVM version 4.2 (clang-503.0.38) (based on LLVM 3.4svn)\nTarget: x86_64-apple-darwin14.0.0\nThread model: posix\n}
     }
   }