Merge pull request #2165 from lf-lang/cpp-praemble-import

Fixed generation of preambles for unused imports

core/src/main/kotlin/org/lflang/generator/cpp/CppGenerator.kt

@@ -70,7 +70,7 @@ class CppGenerator(
             if (targetConfig.get(Ros2Property.INSTANCE)) CppRos2Generator(this) else CppStandaloneGenerator(this)
 
         // generate all core files
-        generateFiles(platformGenerator.srcGenPath)
+        generateFiles(platformGenerator.srcGenPath, getAllImportedResources(resource))
 
         // generate platform specific files
         platformGenerator.generatePlatformFiles()
@@ -117,7 +117,15 @@ class CppGenerator(
         commandFactory.createCommand("git", listOf("checkout", version), libPath).run()
     }
 
-    private fun generateFiles(srcGenPath: Path) {
+    private fun getAllImportedResources(resource: Resource): Set<Resource> {
+        val resources: MutableSet<Resource> = scopeProvider.getImportedResources(resource)
+        val importedRresources = resources.subtract(setOf(resource))
+        resources.addAll(importedRresources.map { getAllImportedResources(it) }.flatten())
+        resources.add(resource)
+        return resources
+    }
+
+    private fun generateFiles(srcGenPath: Path, resources: Set<Resource>) {
         // copy static library files over to the src-gen directory
         val genIncludeDir = srcGenPath.resolve("__include__")
         listOf("lfutil.hh", "time_parser.hh").forEach {
@@ -158,11 +166,12 @@ class CppGenerator(
             FileUtil.writeToFile(reactorCodeMap.generatedCode, srcGenPath.resolve(sourceFile), true)
         }
 
+
         // generate file level preambles for all resources
         for (r in resources) {
-            val generator = CppPreambleGenerator(r.eResource, fileConfig, scopeProvider)
-            val sourceFile = fileConfig.getPreambleSourcePath(r.eResource)
-            val headerFile = fileConfig.getPreambleHeaderPath(r.eResource)
+            val generator = CppPreambleGenerator(r, fileConfig, scopeProvider)
+            val sourceFile = fileConfig.getPreambleSourcePath(r)
+            val headerFile = fileConfig.getPreambleHeaderPath(r)
             val preambleCodeMap = CodeMap.fromGeneratedCode(generator.generateSource())
             cppSources.add(sourceFile)
             codeMaps[srcGenPath.resolve(sourceFile)] = preambleCodeMap

test/Cpp/src/PreambleImport.lf

@@ -0,0 +1,10 @@
+// This tests checks if the preamble of an imported reactor is included correctly even if the reactor is not used.
+target Cpp
+
+import PreambleFoo from "PreambleTest.lf"
+
+main reactor {
+  reaction(startup) {=
+    std::cout << foo() << std::endl;
+  =}
+}

test/Cpp/src/PreambleTest.lf

@@ -1,5 +1,22 @@
 target Cpp
 
+// This is used to test for nested unused imports in PreambleImport.lf
+import Imported from "lib/Imported.lf"
+
+public preamble {=
+  int foo();
+=}
+
+private preamble {=
+  int foo() {
+    return 42;
+  }
+=}
+
+// This is a dummy reactor to test importing of preambles in PreambleImport.lf
+reactor PreambleFoo {
+}
+
 main reactor {
   // This declaration is required on the public reactor interface and therefore needs to be placed
   // in the generated header. This goes to Preamble/Preamble.hh.
@@ -15,17 +32,23 @@ main reactor {
   // This goes to Preamble/Preamble.cc
   private preamble {=
     int add_42(int i) {
-      return i + 42;
+      return i + foo();
     }
   =}
   logical action a: MyStruct
 
   reaction(startup) -> a {=
-    a.schedule({add_42(42), "baz"});
+    a.schedule({add_42(foo()), "baz"});
   =}
 
   reaction(a) {=
     auto& value = *a.get();
     std::cout << "Received " << value.foo << " and '" << value.bar << "'\n";
+    if (value.foo == 84 && value.bar == "baz") {
+      std::cout << "Success!\n";
+    } else {
+      std::cout << "Error!\n";
+      exit(1);
+    }
   =}
 }