implement ConfigureOp#check_executable

build_tests/configure/check_executable_failure.rb

@@ -0,0 +1,3 @@
+configure do
+  check_executable "executable-that-is-not-found"
+end

build_tests/configure/check_executable_no_fail.rb

@@ -0,0 +1,3 @@
+configure do
+  check_executable "executable-that-is-not-found", fail: false
+end

build_tests/configure/check_executable_success.rb

@@ -0,0 +1,3 @@
+configure do
+  check_executable "find"
+end

lib/rscons/application.rb

@@ -115,6 +115,11 @@ module Rscons
             co.check_d_import(*cdi)
           end
         end
+        if ces = @script.check_executables
+          ces.each do |ce|
+            co.check_executable(*ce)
+          end
+        end
       rescue ConfigureOp::ConfigureFailure
         rv = 1
       end

lib/rscons/configure_op.rb

@@ -161,6 +161,27 @@ module Rscons
       common_config_checks(status, options)
     end
 
+    # Check for an executable.
+    def check_executable(executable, options = {})
+      $stdout.write("Checking for executable '#{executable}'... ")
+      found = false
+      if executable["/"] or executable["\\"]
+        if File.file?(executable) and File.executable?(executable)
+          found = true
+          success_message = executable
+        end
+      else
+        path_entries = ENV["PATH"].split(File::PATH_SEPARATOR)
+        path_entries.find do |path_entry|
+          if path = test_path_for_executable(path_entry, executable)
+            found = true
+            success_message = path
+          end
+        end
+      end
+      common_config_checks(found ? 0 : 1, options.merge(success_message: success_message))
+    end
+
     private
 
     # Test a C compiler.
@@ -307,9 +328,12 @@ module Rscons
     #   Whether to fail configuration if the requested item is not found.
     # @option options [String] :set_define
     #   A define to set (in CPPDEFINES) if the requested item is found.
+    # @option options [String] :success_message
+    #   Message to print on success (default "found").
     def common_config_checks(status, options)
+      success_message = options[:success_message] || "found"
       if status == 0
-        Ansi.write($stdout, :green, "found\n")
+        Ansi.write($stdout, :green, "#{success_message}\n")
       else
         if options.has_key?(:fail) and not options[:fail]
           Ansi.write($stdout, :yellow, "not found\n")
@@ -323,5 +347,34 @@ module Rscons
       end
     end
 
+    # Check if a directory contains a certain executable.
+    #
+    # @param path_entry [String]
+    #   Directory to look in.
+    # @param executable [String]
+    #   Executable to look for.
+    def test_path_for_executable(path_entry, executable)
+      is_executable = lambda do |path|
+        File.file?(path) and File.executable?(path)
+      end
+      if RbConfig::CONFIG["host_os"] =~ /mswin|windows|mingw/i
+        executable = executable.downcase
+        dir_entries = Dir.entries(path_entry)
+        dir_entries.find do |entry|
+          path = "#{path_entry}/#{entry}"
+          entry = entry.downcase
+          if ((entry == executable) or
+              (entry == "#{executable}.exe") or
+              (entry == "#{executable}.com") or
+              (entry == "#{executable}.bat")) and is_executable[path]
+            return path
+          end
+        end
+      else
+        path = "#{path_entry}/#{executable}"
+        return path if is_executable[path]
+      end
+    end
+
   end
 end

spec/build_tests_spec.rb

@@ -1698,6 +1698,32 @@ EOF
         expect(result.stdout).to match /Checking for D import 'not\.found'... not found/
       end
     end
+
+    context "check_executable" do
+      it "succeeds when the requested executable is found" do
+        test_dir "configure"
+        result = run_rscons(rsconsfile: "check_executable_success.rb", op: "configure")
+        expect(result.stderr).to eq ""
+        expect(result.status).to eq 0
+        expect(result.stdout).to match /Checking for executable 'find'... .*find/
+      end
+
+      it "fails when the requested executable is not found" do
+        test_dir "configure"
+        result = run_rscons(rsconsfile: "check_executable_failure.rb", op: "configure")
+        expect(result.stderr).to eq ""
+        expect(result.status).to_not eq 0
+        expect(result.stdout).to match /Checking for executable 'executable-that-is-not-found'... not found/
+      end
+
+      it "succeeds when the requested executable is not found but :fail is set to false" do
+        test_dir "configure"
+        result = run_rscons(rsconsfile: "check_executable_no_fail.rb", op: "configure")
+        expect(result.stderr).to eq ""
+        expect(result.status).to eq 0
+        expect(result.stdout).to match /Checking for executable 'executable-that-is-not-found'... not found/
+      end
+    end
   end
 
 end