From d656df54073cb773ceaa7b03bffa30daf6a1c3d6 Mon Sep 17 00:00:00 2001
From: Josh Holtrop <jholtrop@gmail.com>
Date: Wed, 7 Nov 2018 19:05:08 -0500
Subject: [PATCH] implement ConfigureOp#check_d_compiler

---
 build_tests/configure/check_d_compiler.rb     |  3 ++
 .../configure/check_d_compiler_find_first.rb  |  3 ++
 lib/rscons/application.rb                     |  3 ++
 lib/rscons/configure_op.rb                    | 53 +++++++++++++++++++
 spec/build_tests_spec.rb                      | 34 ++++++++++++
 5 files changed, 96 insertions(+)
 create mode 100644 build_tests/configure/check_d_compiler.rb
 create mode 100644 build_tests/configure/check_d_compiler_find_first.rb

diff --git a/build_tests/configure/check_d_compiler.rb b/build_tests/configure/check_d_compiler.rb
new file mode 100644
index 0000000..312355b
--- /dev/null
+++ b/build_tests/configure/check_d_compiler.rb
@@ -0,0 +1,3 @@
+configure do
+  check_d_compiler
+end
diff --git a/build_tests/configure/check_d_compiler_find_first.rb b/build_tests/configure/check_d_compiler_find_first.rb
new file mode 100644
index 0000000..4467e4a
--- /dev/null
+++ b/build_tests/configure/check_d_compiler_find_first.rb
@@ -0,0 +1,3 @@
+configure do
+  check_d_compiler "gdc", "ldc2"
+end
diff --git a/lib/rscons/application.rb b/lib/rscons/application.rb
index 12e4a21..e7c005b 100644
--- a/lib/rscons/application.rb
+++ b/lib/rscons/application.rb
@@ -91,6 +91,9 @@ module Rscons
         if ccc = @script.check_cxx_compiler
           co.check_cxx_compiler(ccc)
         end
+        if cdc = @script.check_d_compiler
+          co.check_d_compiler(cdc)
+        end
       rescue ConfigureOp::ConfigureFailure
         rv = 1
       end
diff --git a/lib/rscons/configure_op.rb b/lib/rscons/configure_op.rb
index 0225e42..31da29c 100644
--- a/lib/rscons/configure_op.rb
+++ b/lib/rscons/configure_op.rb
@@ -72,6 +72,29 @@ module Rscons
       end
     end
 
+    # Check for a working D compiler.
+    #
+    # @param cdc [Array<String>]
+    #   D compiler(s) to check for.
+    #
+    # @return [void]
+    def check_d_compiler(cdc)
+      $stdout.write("Checking for D compiler... ")
+      if cdc.empty?
+        # Default D compiler search array.
+        cdc = %w[gdc ldc2]
+      end
+      dc = cdc.find do |dc|
+        test_d_compiler(dc)
+      end
+      if dc
+        Ansi.write($stdout, :green, dc, "\n")
+      else
+        Ansi.write($stdout, :red, "not found\n")
+        raise ConfigureFailure.new
+      end
+    end
+
     private
 
     # Test a C compiler.
@@ -135,6 +158,36 @@ module Rscons
       status == 0
     end
 
+    # Test a D compiler.
+    #
+    # @param dc [String]
+    #   D compiler to test.
+    #
+    # @return [Boolean]
+    #   Whether the D compiler tested successfully.
+    def test_d_compiler(dc)
+      File.open("#{@work_dir}/cfgtest.d", "wb") do |fh|
+        fh.puts <<-EOF
+          import std.stdio;
+          int main() {
+            writeln("Hello.");
+            return 0;
+          }
+        EOF
+      end
+      case dc
+      when "gdc"
+        command = %W[gdc -o #{@work_dir}/cfgtest.exe #{@work_dir}/cfgtest.d]
+      when "ldc2"
+        command = %W[ldc2 -of=#{@work_dir}/cfgtest.exe #{@work_dir}/cfgtest.d]
+      else
+        $stderr.puts "Unknown D compiler (#{dc})"
+        raise ConfigureFailure.new
+      end
+      _, _, status = log_and_test_command(command)
+      status == 0
+    end
+
     # Execute a test command and log the result.
     def log_and_test_command(command)
       begin
diff --git a/spec/build_tests_spec.rb b/spec/build_tests_spec.rb
index ddf9bb1..bcdbfd5 100644
--- a/spec/build_tests_spec.rb
+++ b/spec/build_tests_spec.rb
@@ -1568,6 +1568,40 @@ EOF
         end
       end
     end
+
+    context "check_d_compiler" do
+      {"check_d_compiler.rb" => "when no arguments are given",
+       "check_d_compiler_find_first.rb" => "when arguments are given"}.each_pair do |rsconsfile, desc|
+        context desc do
+          it "finds the first listed D compiler" do
+            test_dir "configure"
+            result = run_rscons(rsconsfile: rsconsfile, op: "configure")
+            expect(result.stderr).to eq ""
+            expect(result.status).to eq 0
+            expect(result.stdout).to match /Checking for D compiler\.\.\. gdc/
+          end
+
+          it "finds the second listed D compiler" do
+            test_dir "configure"
+            create_exe "gdc", "exit 1"
+            result = run_rscons(rsconsfile: rsconsfile, op: "configure")
+            expect(result.stderr).to eq ""
+            expect(result.status).to eq 0
+            expect(result.stdout).to match /Checking for D compiler\.\.\. ldc2/
+          end
+
+          it "fails to configure when it cannot find a D compiler" do
+            test_dir "configure"
+            create_exe "gdc", "exit 1"
+            create_exe "ldc2", "exit 1"
+            result = run_rscons(rsconsfile: rsconsfile, op: "configure")
+            expect(result.stderr).to eq ""
+            expect(result.status).to_not eq 0
+            expect(result.stdout).to match /Checking for D compiler\.\.\. not found/
+          end
+        end
+      end
+    end
   end
 
 end