Fix module being ignored when it cannot be found based on include dir. (mono#1736)

Author: tritao

src/CLI/Generator.cs

@@ -108,6 +108,9 @@ public bool ValidateOptions(List<string> messages)
             if (string.IsNullOrEmpty(options.OutputNamespace))
                 options.OutputNamespace = moduleName;
 
+            if (options.IncludeDirs.Count == 0)
+                options.IncludeDirs.Add(Path.GetDirectoryName(options.HeaderFiles.First()));
+
             SetupTargetTriple();
 
             return true;

src/Generator/Driver.cs

@@ -439,7 +439,12 @@ public static void Run(ILibrary library)
             }
 
             new CleanUnitPass { Context = driver.Context }.VisitASTContext(driver.Context.ASTContext);
-            options.Modules.RemoveAll(m => m != options.SystemModule && !m.Units.GetGenerated().Any());
+            foreach (var module in options.Modules.Where(
+                         m => m != options.SystemModule && !m.Units.GetGenerated().Any()))
+            {
+                Diagnostics.Message($"Removing module {module} because no translation units are generated...");
+                options.Modules.Remove(module);
+            }
 
             if (!options.Quiet)
                 Diagnostics.Message("Processing code...");

src/Generator/Passes/CleanUnitPass.cs

@@ -31,14 +31,9 @@ private Module GetModule(TranslationUnit unit)
                 includeDir = ".";
             includeDir = Path.GetFullPath(includeDir);
 
-            Module module = Options.Modules.Find(
-                m => m.IncludeDirs.Any(i => Path.GetFullPath(i) == includeDir));
-            if (module == null)
-            {
-                unit.ExplicitlyIgnore();
-                module = Options.Modules[1];
-            }
-            return module;
+            return Options.Modules.FirstOrDefault(
+                       m => m.IncludeDirs.Any(i => Path.GetFullPath(i) == includeDir)) ??
+                   Options.Modules[1];
         }
 
         public override bool VisitDeclarationContext(DeclarationContext context)