Watchdog support for the C target

org.lflang/src/org/lflang/ASTUtils.java

@@ -32,7 +32,6 @@
 import java.util.LinkedHashSet;
 import java.util.List;
 import java.util.Map;
-import java.util.Objects;
 import java.util.Set;
 import java.util.function.Predicate;
 import java.util.regex.Matcher;
@@ -61,8 +60,6 @@
 import org.lflang.generator.ReactorInstance;
 import org.lflang.lf.Action;
 import org.lflang.lf.Assignment;
-import org.lflang.lf.AttrParm;
-import org.lflang.lf.Attribute;
 import org.lflang.lf.Code;
 import org.lflang.lf.Connection;
 import org.lflang.lf.Element;
@@ -92,6 +89,7 @@
 import org.lflang.lf.Type;
 import org.lflang.lf.VarRef;
 import org.lflang.lf.Variable;
+import org.lflang.lf.Watchdog;
 import org.lflang.lf.WidthSpec;
 import org.lflang.lf.WidthTerm;
 import org.lflang.util.StringUtil;
@@ -263,7 +261,6 @@ public static Target getTarget(EObject object) {
 
     /**
      * Add a new target property to the given resource.
-     *
      * This also creates a config object if the resource does not yey have one.
      *
      * @param resource The resource to modify
@@ -292,11 +289,11 @@ public static boolean hasMultipleConnections(Connection connection) {
         if (connection.getLeftPorts().size() > 1 || connection.getRightPorts().size() > 1) {
             return true;
         }
-        VarRef leftPort  = connection.getLeftPorts().get(0);
+        VarRef leftPort = connection.getLeftPorts().get(0);
         VarRef rightPort = connection.getRightPorts().get(0);
-        Instantiation leftContainer  = leftPort.getContainer();
+        Instantiation leftContainer = leftPort.getContainer();
         Instantiation rightContainer = rightPort.getContainer();
-        Port leftPortAsPort  = (Port) leftPort.getVariable();
+        Port leftPortAsPort = (Port) leftPort.getVariable();
         Port rightPortAsPort = (Port) rightPort.getVariable();
         return leftPortAsPort.getWidthSpec() != null
             || leftContainer != null && leftContainer.getWidthSpec() != null
@@ -450,6 +447,16 @@ public static List<Reaction> allReactions(Reactor definition) {
         return ASTUtils.collectElements(definition, featurePackage.getReactor_Reactions());
     }
 
+    /**
+     * Given a reactor class, return a list of all its watchdogs.
+     *
+     * @param definition Reactor class definition
+     * @return List<Watchdog>
+     */
+    public static List<Watchdog> allWatchdogs(Reactor definition) {
+        return ASTUtils.collectElements(definition, featurePackage.getReactor_Watchdogs());
+    }
+
     /**
      * Given a reactor class, return a list of all its state variables,
      * which includes state variables of base classes that it extends.
@@ -485,7 +492,7 @@ public static List<Mode> allModes(Reactor definition) {
     public static List<Reactor> recursiveChildren(ReactorInstance r) {
         List<Reactor> ret = new ArrayList<>();
         ret.add(r.reactorDefinition);
-        for (var child: r.children) {
+        for (var child : r.children) {
             ret.addAll(recursiveChildren(child));
         }
         return ret;
@@ -790,7 +797,6 @@ private static Element toElement(String str, boolean addQuotes) {
         Element e = LfFactory.eINSTANCE.createElement();
         e.setLiteral(strToReturn);
         return e;
-
     }
 
     /**
@@ -937,12 +943,12 @@ public static boolean isFloat(String literal) {
         return true;
     }
 
-	/**
+    /**
      * Report whether the given code is an integer number or not.
      * @param code AST node to inspect.
      * @return True if the given code is an integer, false otherwise.
      */
-	public static boolean isInteger(Code code) {
+    public static boolean isInteger(Code code) {
         return isInteger(toText(code));
     }
 
@@ -966,13 +972,13 @@ public static boolean isInteger(Expression expr) {
      * @return True if the argument denotes a valid time, false otherwise.
      */
     public static boolean isValidTime(Expression expr) {
-            if (expr instanceof ParameterReference) {
-                return isOfTimeType(((ParameterReference)expr).getParameter());
-            } else if (expr instanceof Time) {
-                return isValidTime((Time) expr);
-            } else if (expr instanceof Literal) {
-                return isZero(((Literal) expr).getLiteral());
-            }
+        if (expr instanceof ParameterReference) {
+            return isOfTimeType(((ParameterReference) expr).getParameter());
+        } else if (expr instanceof Time) {
+            return isValidTime((Time) expr);
+        } else if (expr instanceof Literal) {
+            return isZero(((Literal) expr).getLiteral());
+        }
         return false;
     }
 
@@ -1021,7 +1027,7 @@ public static boolean isListInitializer(Initializer init) {
      * can be inferred: "time" and "timeList". Return the
      * "undefined" type if neither can be inferred.
      *
-     * @param type     Explicit type declared on the declaration
+     * @param type Explicit type declared on the declaration
      * @param init The initializer expression
      * @return The inferred type, or "undefined" if none could be inferred.
      */
@@ -1114,8 +1120,6 @@ public static InferredType getInferredType(Port p) {
         return getInferredType(p.getType(), null);
     }
 
-
-
     /**
      * If the given string can be recognized as a floating-point number that has a leading decimal point,
      * prepend the string with a zero and return it. Otherwise, return the original string.

org.lflang/src/org/lflang/LinguaFranca.xtext

@@ -87,6 +87,7 @@ Reactor:
         | (outputs+=Output)
         | (timers+=Timer)
         | (actions+=Action)
+        | (watchdogs+=Watchdog)
         | (instantiations+=Instantiation)
         | (connections+=Connection)
         | (reactions+=Reaction)
@@ -174,6 +175,7 @@ Mode:
         (stateVars+=StateVar) |
         (timers+=Timer) |
         (actions+=Action) |
+        (watchdogs+=Watchdog) |
         (instantiations+=Instantiation) |
         (connections+=Connection) |
         (reactions+=Reaction)
@@ -213,6 +215,11 @@ BuiltinTriggerRef:
 Deadline:
     'deadline' '(' delay=Expression ')' code=Code;
 
+Watchdog:
+    'watchdog' name=ID '(' timeout=Expression ')'
+    ('->' effects+=VarRefOrModeTransition (',' effects+=VarRefOrModeTransition)*)?
+    code=Code;
+
 STP:
     'STP' '(' value=Expression ')' code=Code;
 
@@ -273,7 +280,7 @@ TypedVariable:
 ;
 
 Variable:
-    TypedVariable | Timer | Mode;
+    TypedVariable | Timer | Mode | Watchdog;
 
 VarRef:
     (variable=[Variable] | container=[Instantiation] '.' variable=[Variable]
@@ -457,7 +464,7 @@ SignedFloat:
 // Just escaping with \ is not a good idea because then every \ has to be escaped \\.
 // Perhaps the string EQUALS_BRACE could become '=}'?
 Code:
-    //{Code} '{=' (tokens+=Token)* '=}'
+    // {Code} '{=' (tokens+=Token)* '=}'
     {Code} '{=' body=Body '=}'
 ;
 
@@ -504,7 +511,8 @@ Token:
     'mutable' | 'input' | 'output' | 'timer' | 'action' | 'reaction' |
     'startup' | 'shutdown' | 'after' | 'deadline' | 'mutation' | 'preamble' |
     'new' | 'federated' | 'at' | 'as' | 'from' | 'widthof' | 'const' | 'method' |
-    'interleaved' | 'mode' | 'initial' | 'reset' | 'history' | 'named' |
+    'interleaved' | 'mode' | 'initial' | 'reset' | 'history' | 'watchdog' | 'named' |
+
     // Other terminals
     NEGINT | TRUE | FALSE |
     // Action origins

org.lflang/src/org/lflang/ast/IsEqual.java

@@ -60,6 +60,7 @@
 import org.lflang.lf.TypedVariable;
 import org.lflang.lf.VarRef;
 import org.lflang.lf.Variable;
+import org.lflang.lf.Watchdog;
 import org.lflang.lf.WidthSpec;
 import org.lflang.lf.WidthTerm;
 import org.lflang.lf.util.LfSwitch;
@@ -319,7 +320,6 @@ public Boolean caseSTP(STP object) {
             .conclusion;
     }
 
-
     @Override
     public Boolean casePreamble(Preamble object) {
         return new ComparisonMachine<>(object, Preamble.class)
@@ -496,6 +496,16 @@ public Boolean caseArraySpec(ArraySpec object) {
             .conclusion;
     }
 
+    @Override
+    public Boolean caseWatchdog(Watchdog object) {
+        return new ComparisonMachine<>(object, Watchdog.class)
+            .equalAsObjects(Watchdog::getName)
+            .equivalent(Watchdog::getTimeout)
+            .listsEquivalent(Watchdog::getEffects)
+            .equivalent(Watchdog::getCode)
+            .conclusion;
+    }
+
     @Override
     public Boolean caseWidthSpec(WidthSpec object) {
         return new ComparisonMachine<>(object, WidthSpec.class)

org.lflang/src/org/lflang/ast/ToLf.java

@@ -76,6 +76,7 @@
 import org.lflang.lf.VarRef;
 import org.lflang.lf.Variable;
 import org.lflang.lf.Visibility;
+import org.lflang.lf.Watchdog;
 import org.lflang.lf.WidthSpec;
 import org.lflang.lf.WidthTerm;
 import org.lflang.lf.util.LfSwitch;
@@ -393,6 +394,7 @@ public MalleableString caseReactor(Reactor object) {
     //     | (outputs+=Output)
     //     | (timers+=Timer)
     //     | (actions+=Action)
+    //     | (watchdogs+=Watchdog)
     //     | (instantiations+=Instantiation)
     //     | (connections+=Connection)
     //     | (reactions+=Reaction)
@@ -410,6 +412,7 @@ public MalleableString caseReactor(Reactor object) {
                 object.getOutputs(),
                 object.getTimers(),
                 object.getActions(),
+                object.getWatchdogs(),
                 object.getInstantiations(),
                 object.getConnections(),
                 object.getStateVars()),
@@ -656,6 +659,40 @@ public MalleableString caseDeadline(Deadline object) {
     return handler(object, "deadline", Deadline::getDelay, Deadline::getCode);
   }
 
+  @Override
+  public MalleableString caseWatchdog(Watchdog object) {
+    // 'watchdog' name=ID '(' timeout=Expression ')'
+    // ('->' effects+=VarRefOrModeTransition (',' effects+=VarRefOrModeTransition)*)?
+    // code=Code;
+
+    Builder msb = new Builder();
+    msb.append("watchdog ");
+    msb.append(object.getName());
+    msb.append(list(true, object.getTimeout()));
+
+    if (!object.getEffects().isEmpty()) {
+      List<Mode> allModes = ASTUtils.allModes(ASTUtils.getEnclosingReactor(object));
+      msb.append(" -> ", " ->\n")
+          .append(
+              object.getEffects().stream()
+                  .map(
+                      varRef ->
+                          (allModes.stream()
+                                  .anyMatch(
+                                      m -> m.getName().equals(varRef.getVariable().getName())))
+                              ? new Builder()
+                                  .append(varRef.getTransition())
+                                  .append("(")
+                                  .append(doSwitch(varRef))
+                                  .append(")")
+                                  .get()
+                              : doSwitch(varRef))
+                  .collect(new Joiner(", ")));
+    }
+    msb.append(" ").append(doSwitch(object.getCode()));
+    return msb.get();
+  }
+
   @Override
   public MalleableString caseSTP(STP object) {
     // 'STP' '(' value=Expression ')' code=Code
@@ -844,9 +881,8 @@ public MalleableString caseInitializer(Initializer object) {
   }
 
   /**
-   * Return true if the initializer should be output with an equals initializer.
-   * Old-style assignments with parentheses are also output that
-   * way to help with the transition.
+   * Return true if the initializer should be output with an equals initializer. Old-style
+   * assignments with parentheses are also output that way to help with the transition.
    */
   private boolean shouldOutputAsAssignment(Initializer init) {
     return init.isAssign()
@@ -882,7 +918,6 @@ private MalleableString initializer(Initializer init) {
     return list(", ", prefix, suffix, false, false, init.getExprs());
   }
 
-
   @Override
   public MalleableString caseParameter(Parameter object) {
     // name=ID (':' (type=Type))?