[C] do not generate code without main reactor

org.lflang/src/org/lflang/generator/GeneratorBase.java

@@ -354,10 +354,15 @@ public void doGenerate(Resource resource, LFGeneratorContext context) {
             .map(it -> GeneratorUtils.getLFResource(it, fileConfig.getSrcGenBasePath(), context, errorReporter))
             .collect(Collectors.toList())
         );
-        GeneratorUtils.accommodatePhysicalActionsIfPresent(allResources, getTarget(), targetConfig, errorReporter);
+        GeneratorUtils.accommodatePhysicalActionsIfPresent(
+            allResources, 
+            getTarget().setsKeepAliveOptionAutomatically(), 
+            targetConfig, 
+            errorReporter
+        );
         // FIXME: Should the GeneratorBase pull in `files` from imported
         // resources?
-                
+
         // Reroute connections that have delays associated with them via 
         // generated delay reactors.
         transformDelays();

org.lflang/src/org/lflang/generator/GeneratorUtils.java

@@ -30,6 +30,7 @@
 import org.lflang.lf.Action;
 import org.lflang.lf.ActionOrigin;
 import org.lflang.lf.Import;
+import org.lflang.lf.Instantiation;
 import org.lflang.lf.KeyValuePair;
 import org.lflang.lf.KeyValuePairs;
 import org.lflang.lf.Model;
@@ -55,16 +56,14 @@ private GeneratorUtils() {
      * Return the target declaration found in the given resource.
      */
     public static TargetDecl findTarget(Resource resource) {
+        int cnt = 0;
         TargetDecl targetDecl = null;
         for (TargetDecl t : findAll(resource, TargetDecl.class)) { // getAllContents should never return null.
-            if (targetDecl != null) {
-                throw new InvalidSourceException("There is more than one target!"); // FIXME: check this in validator
-            }
             targetDecl = t;
+            cnt++;
         }
-        if (targetDecl == null) {
-            throw new InvalidSourceException("No target found!");
-        }
+        if (cnt > 1)  throw new InvalidSourceException("There is more than one target!"); // FIXME: check this in validator
+        if (cnt == 0) throw new InvalidSourceException("No target found!");
         return targetDecl;
     }
 
@@ -130,30 +129,31 @@ public static void setTargetConfig(
      */
     public static void accommodatePhysicalActionsIfPresent(
         List<Resource> resources,
-        Target target,
+        boolean setsKeepAliveOptionAutomatically,
         TargetConfig targetConfig,
         ErrorReporter errorReporter
     ) {
-        if (!target.setsKeepAliveOptionAutomatically()) {
+        if (!setsKeepAliveOptionAutomatically) {
             return;
         }
         for (Resource resource : resources) {
             for (Action action : findAll(resource, Action.class)) {
-                if (action.getOrigin() == ActionOrigin.PHYSICAL) {
+                if (action.getOrigin() == ActionOrigin.PHYSICAL && 
                     // Check if the user has explicitly set keepalive to false
-                    if (!targetConfig.setByUser.contains(TargetProperty.KEEPALIVE) && !targetConfig.keepalive) {
-                        // If not, set it to true
-                        targetConfig.keepalive = true;
-                        errorReporter.reportWarning(
-                            action,
-                            String.format(
-                                "Setting %s to true because of the physical action %s.",
-                                TargetProperty.KEEPALIVE.getDisplayName(),
-                                action.getName()
-                            )
-                        );
-                        return;
-                    }
+                    !targetConfig.setByUser.contains(TargetProperty.KEEPALIVE) && 
+                    !targetConfig.keepalive
+                ) {
+                    // If not, set it to true
+                    targetConfig.keepalive = true;
+                    errorReporter.reportWarning(
+                        action,
+                        String.format(
+                            "Setting %s to true because of the physical action %s.",
+                            TargetProperty.KEEPALIVE.getDisplayName(),
+                            action.getName()
+                        )
+                    );
+                    return;
                 }
             }
         }
@@ -306,14 +306,13 @@ public static LFResource getLFResource(
             List<KeyValuePair> pairs = config.getPairs();
             TargetProperty.set(targetConfig, pairs != null ? pairs : List.of(), errorReporter);
         }
-        FileConfig fc;
         try {
-            fc = new FileConfig(resource, srcGenBasePath, context.useHierarchicalBin());
+            FileConfig fc = new FileConfig(resource, srcGenBasePath, context.useHierarchicalBin());
+            return new LFResource(resource, fc, targetConfig);
         } catch (IOException e) {
             throw new RuntimeException("Failed to instantiate an imported resource because an I/O error "
                                            + "occurred.");
         }
-        return new LFResource(resource, fc, targetConfig);
     }
 
     /**
@@ -341,4 +340,29 @@ public static void refreshProject(Resource resource, Mode compilerMode) {
     public static boolean isHostWindows() {
         return System.getProperty("os.name").toLowerCase().contains("win");
     }
+
+    /**
+     * Check whether code can be generated; report any problems
+     * and inform the context accordingly.
+     * @return Whether it is possible to generate code.
+     */
+    public static boolean canGenerate(
+        Boolean errorsOccurred,
+        Instantiation mainDef,
+        ErrorReporter errorReporter,
+        LFGeneratorContext context
+    ) {
+        // stop if there are any errors found in the program by doGenerate() in GeneratorBase
+        if (errorsOccurred) {
+            context.finish(GeneratorResult.FAILED);
+            return false;
+        }
+        // abort if there is no main reactor
+        if (mainDef == null) {
+            errorReporter.reportWarning("WARNING: The given Lingua Franca program does not define a main reactor. Therefore, no code was generated.");
+            context.finish(GeneratorResult.NOTHING);
+            return false;
+        }
+        return true;
+    }
 }

org.lflang/src/org/lflang/generator/GeneratorUtils.kt

@@ -8,7 +8,6 @@ import org.lflang.toUnixString
 import org.lflang.toTextTokenBased
 import org.lflang.lf.Instantiation
 
-
 /** A transparent type alias to document when a string contains target code. */
 typealias TargetCode = String
 
@@ -43,28 +42,3 @@ fun EObject.locationInfo(): LocationInfo {
         lfText = toTextTokenBased() ?: ""
     )
 }
-
-/**
- * Check whether code can be generated; report any problems
- * and inform the context accordingly.
- * @return Whether it is possible to generate code.
- */
-fun canGenerate(
-    errorsOccurred: Boolean,
-    mainDef: Instantiation?,
-    errorReporter: ErrorReporter,
-    context: LFGeneratorContext
-): Boolean {
-    // stop if there are any errors found in the program by doGenerate() in GeneratorBase
-    if (errorsOccurred) {
-        context.finish(GeneratorResult.FAILED)
-        return false
-    }
-    // abort if there is no main reactor
-    if (mainDef == null) {
-        errorReporter.reportWarning("WARNING: The given Lingua Franca program does not define a main reactor. Therefore, no code was generated.")
-        context.finish(GeneratorResult.NOTHING)
-        return false
-    }
-    return true
-}

org.lflang/src/org/lflang/generator/c/CGenerator.xtend

@@ -334,12 +334,6 @@ class CGenerator extends GeneratorBase {
 
     ////////////////////////////////////////////
     //// Public methods
-
-    override printInfo(LFGeneratorContext.Mode mode) {
-        super.printInfo(mode)
-        println('******** generated binaries: ' + fileConfig.binPath)
-    }
-
     /**
      * Set C-specific default target configurations if needed.
      */
@@ -385,6 +379,7 @@ class CGenerator extends GeneratorBase {
                             '''Using the threaded C runtime to allow for asynchronous handling of«
                             » physical action «action.name».'''
                         );
+                        return;
                     }
                 }
             }
@@ -435,9 +430,10 @@ class CGenerator extends GeneratorBase {
      *     whether it is a standalone context
      */
     override void doGenerate(Resource resource, LFGeneratorContext context) {
-
-        // The following generates code needed by all the reactors.
         super.doGenerate(resource, context)
+
+        if (!GeneratorUtils.canGenerate(errorsOccurred, mainDef, errorReporter, context)) return;
+
         accommodatePhysicalActionsIfPresent()
         setCSpecificDefaults(context)
         generatePreamble()
@@ -936,6 +932,7 @@ class CGenerator extends GeneratorBase {
                     GeneratorResult.Status.COMPILED, fileConfig.name, fileConfig, null
                 );
             }
+            println("Compiled binary is in " + fileConfig.binPath);
         } else {
             context.finish(GeneratorResult.GENERATED_NO_EXECUTABLE.apply(null));
         }

org.lflang/src/org/lflang/generator/cpp/CppGenerator.kt

@@ -39,7 +39,7 @@ import org.lflang.generator.GeneratorResult
 import org.lflang.generator.IntegratedBuilder
 import org.lflang.generator.LFGeneratorContext
 import org.lflang.generator.TargetTypes
-import org.lflang.generator.canGenerate
+import org.lflang.generator.GeneratorUtils.canGenerate
 import org.lflang.isGeneric
 import org.lflang.lf.Action
 import org.lflang.lf.VarRef

org.lflang/src/org/lflang/generator/rust/RustGenerator.kt

@@ -28,7 +28,7 @@ import org.eclipse.emf.ecore.resource.Resource
 import org.lflang.ErrorReporter
 import org.lflang.Target
 import org.lflang.TargetProperty.BuildType
-import org.lflang.generator.canGenerate
+import org.lflang.generator.GeneratorUtils.canGenerate
 import org.lflang.generator.CodeMap
 import org.lflang.generator.GeneratorBase
 import org.lflang.generator.GeneratorResult

org.lflang/src/org/lflang/generator/ts/TSGenerator.kt

@@ -45,7 +45,7 @@ import org.lflang.generator.PrependOperator
 import org.lflang.generator.SubContext
 import org.lflang.generator.TargetTypes
 import org.lflang.generator.ValueGenerator
-import org.lflang.generator.canGenerate
+import org.lflang.generator.GeneratorUtils.canGenerate
 import org.lflang.inferredType
 import org.lflang.lf.Action
 import org.lflang.lf.Delay