Check for use before assign in functions (#9761)

Fixes #9717

OMCompiler/Compiler/NFFrontEnd/NFFunction.mo

@@ -1451,6 +1451,10 @@ uniontype Function
       end if;
     end if;
 
+    if not InstContext.inRelaxed(context) then
+      checkUseBeforeAssign(fn);
+    end if;
+
     // Sort the local variables based on their dependencies.
     fn.locals := sortLocals(fn.locals, InstNode.info(fn.node));
   end typeFunctionBody;
@@ -2599,6 +2603,200 @@ protected
       UnorderedMap.add(key, true, interface_map);
     end for;
   end getDerivative;
+
+  function checkUseBeforeAssign
+    "Checks if any output or local variables in a function are used
+     uninitialized and prints warnings for such uses."
+    input Function fn;
+  protected
+    Vector<InstNode> unassigned;
+    list<Statement> body;
+  algorithm
+    // Skip external and builtin functions.
+    if isExternal(fn) or isBuiltin(fn) then
+      return;
+    end if;
+
+    unassigned := Vector.new<InstNode>();
+    addUnassignedComponents(unassigned, fn.outputs);
+    addUnassignedComponents(unassigned, fn.locals);
+
+    body := getBody(fn);
+    checkUseBeforeAssign2(unassigned, body);
+  end checkUseBeforeAssign;
+
+  function addUnassignedComponents
+    input Vector<InstNode> unassigned;
+    input list<InstNode> variables;
+  protected
+    Type ty;
+  algorithm
+    for var in variables loop
+      ty := InstNode.getType(var);
+
+      if Type.isScalarBuiltin(ty) and not Component.hasBinding(InstNode.component(var)) then
+        Vector.push(unassigned, var);
+      end if;
+    end for;
+  end addUnassignedComponents;
+
+  function checkUseBeforeAssign2
+    input Vector<InstNode> unassigned;
+    input list<Statement> statements;
+  protected
+    SourceInfo info;
+  algorithm
+    for stmt in statements loop
+      info := Statement.info(stmt);
+
+      () := match stmt
+        case Statement.ASSIGNMENT()
+          algorithm
+            checkUseBeforeAssignExp(unassigned, stmt.rhs, info);
+            markAssignedOutput(unassigned, stmt.lhs);
+          then
+            ();
+
+        case Statement.FOR()
+          algorithm
+            if isSome(stmt.range) then
+              checkUseBeforeAssignExp(unassigned, Util.getOption(stmt.range), info);
+            end if;
+
+            checkUseBeforeAssign2(unassigned, stmt.body);
+          then
+            ();
+
+        case Statement.IF()
+          algorithm
+            checkUseBeforeAssignIf(unassigned, stmt.branches, info);
+          then
+            ();
+
+        case Statement.ASSERT()
+          algorithm
+            checkUseBeforeAssignExp(unassigned, stmt.condition, info);
+            checkUseBeforeAssignExp(unassigned, stmt.message, info);
+            checkUseBeforeAssignExp(unassigned, stmt.level, info);
+          then
+            ();
+
+        case Statement.WHILE()
+          algorithm
+            checkUseBeforeAssignExp(unassigned, stmt.condition, info);
+            checkUseBeforeAssign2(unassigned, stmt.body);
+          then
+            ();
+
+        else ();
+      end match;
+    end for;
+  end checkUseBeforeAssign2;
+
+  function markAssignedOutput
+    input Vector<InstNode> unassigned;
+    input Expression assignedExp;
+  protected
+    InstNode node;
+    Integer index;
+  algorithm
+    () := match assignedExp
+      case Expression.CREF()
+        algorithm
+          node := ComponentRef.node(ComponentRef.last(assignedExp.cref));
+          (_, index) := Vector.find(unassigned, function InstNode.refEqual(node1 = node));
+
+          if index > 0 then
+            Vector.remove(unassigned, index);
+          end if;
+        then
+          ();
+
+      case Expression.TUPLE()
+        algorithm
+          for e in assignedExp.elements loop
+            markAssignedOutput(unassigned, e);
+          end for;
+        then
+          ();
+
+      else ();
+    end match;
+  end markAssignedOutput;
+
+  function checkUseBeforeAssignIf
+    input Vector<InstNode> unassigned;
+    input list<tuple<Expression, list<Statement>>> branches;
+    input SourceInfo info;
+  protected
+    Vector<InstNode> unassigned_branch;
+    list<InstNode> assigned = {};
+    Integer index;
+  algorithm
+    for b in branches loop
+      checkUseBeforeAssignExp(unassigned, Util.tuple21(b), info);
+    end for;
+
+    // Check each branch separately, then assume that any variables that were
+    // assigned (or incorrectly used) in at least one branch are assigned after
+    // the if-statement to avoid false positives.
+    for b in branches loop
+      unassigned_branch := Vector.copy(unassigned);
+      checkUseBeforeAssign2(unassigned_branch, Util.tuple22(b));
+
+      if Vector.size(unassigned) <> Vector.size(unassigned_branch) then
+        assigned := listAppend(
+          List.setDifferenceOnTrue(Vector.toList(unassigned), Vector.toList(unassigned_branch), InstNode.refEqual),
+          assigned);
+      end if;
+    end for;
+
+    if not listEmpty(assigned) then
+      assigned := List.uniqueOnTrue(assigned, InstNode.refEqual);
+
+      for a in assigned loop
+        (_, index) := Vector.find(unassigned, function InstNode.refEqual(node1 = a));
+
+        if index > 0 then
+          Vector.remove(unassigned, index);
+        end if;
+      end for;
+    end if;
+  end checkUseBeforeAssignIf;
+
+  function checkUseBeforeAssignExp
+    input Vector<InstNode> unassigned;
+    input Expression exp;
+    input SourceInfo info;
+  algorithm
+    Expression.apply(exp,
+      function checkUseBeforeAssignExp_traverse(unassigned = unassigned, info = info));
+  end checkUseBeforeAssignExp;
+
+  function checkUseBeforeAssignExp_traverse
+    input Vector<InstNode> unassigned;
+    input Expression exp;
+    input SourceInfo info;
+  protected
+    Integer index;
+    InstNode node;
+  algorithm
+    () := match exp
+      case Expression.CREF()
+        algorithm
+          node := ComponentRef.node(ComponentRef.last(exp.cref));
+          (_, index) := Vector.find(unassigned, function InstNode.refEqual(node1 = node));
+
+          if index > 0 then
+            Vector.remove(unassigned, index);
+            Error.addSourceMessage(Error.WARNING_DEF_USE, {InstNode.name(node)}, info);
+          end if;
+        then
+          ();
+
+      else ();
+    end match;
+  end checkUseBeforeAssignExp_traverse;
 end Function;
 
 annotation(__OpenModelica_Interface="frontend");

testsuite/flattening/modelica/scodeinst/FunctionUnitialized1.mo

@@ -0,0 +1,37 @@
+// name: FunctionUnitialized1
+// keywords:
+// status: correct
+// cflags: -d=newInst
+//
+//
+
+model FunctionUnitialized1
+  Real y = f(time);
+  function f
+    input Real x;
+    output Real y;
+  protected
+    Real z;
+  algorithm
+     y := z + x + y;
+     y := y + 1;
+  end f;
+end FunctionUnitialized1;
+
+// Result:
+// function FunctionUnitialized1.f
+//   input Real x;
+//   output Real y;
+//   protected Real z;
+// algorithm
+//   y := z + x + y;
+//   y := y + 1.0;
+// end FunctionUnitialized1.f;
+//
+// class FunctionUnitialized1
+//   Real y = FunctionUnitialized1.f(time);
+// end FunctionUnitialized1;
+// [flattening/modelica/scodeinst/FunctionUnitialized1.mo:16:6-16:20:writable] Warning: z was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [flattening/modelica/scodeinst/FunctionUnitialized1.mo:16:6-16:20:writable] Warning: y was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+//
+// endResult

testsuite/flattening/modelica/scodeinst/FunctionUnitialized2.mo

@@ -0,0 +1,48 @@
+// name: FunctionUnitialized2
+// keywords:
+// status: correct
+// cflags: -d=newInst
+//
+//
+
+model FunctionUnitialized2
+  Real y = f(time);
+
+  function f
+    input Real x;
+    output Real y;
+  protected
+    Real z, w, u;
+  algorithm
+    if x > 1 then
+      z := 0;
+    else
+      u := 1;
+    end if;
+
+    y := z + w + u;
+  end f;
+end FunctionUnitialized2;
+
+// Result:
+// function FunctionUnitialized2.f
+//   input Real x;
+//   output Real y;
+//   protected Real z;
+//   protected Real w;
+//   protected Real u;
+// algorithm
+//   if x > 1.0 then
+//     z := 0.0;
+//   else
+//     u := 1.0;
+//   end if;
+//   y := z + w + u;
+// end FunctionUnitialized2.f;
+//
+// class FunctionUnitialized2
+//   Real y = FunctionUnitialized2.f(time);
+// end FunctionUnitialized2;
+// [flattening/modelica/scodeinst/FunctionUnitialized2.mo:23:5-23:19:writable] Warning: w was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+//
+// endResult

testsuite/flattening/modelica/scodeinst/Makefile

@@ -662,6 +662,8 @@ FunctionSections3.mo \
 FunctionSections4.mo \
 FunctionSections5.mo \
 FunctionStreamPrefix.mo \
+FunctionUnitialized1.mo \
+FunctionUnitialized2.mo \
 IfConnect1.mo \
 IfConnect2.mo \
 IfConnect3.mo \

testsuite/openmodelica/dataReconciliation/TSP_FourFlows.mos

@@ -2270,5 +2270,12 @@ getErrorString();
 // [ThermoSysPro 3.2.0/WaterSteam/Junctions/Mixer2.mo:17:3-18:52:writable] Warning: Connector Cs is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
 // [ThermoSysPro 3.2.0/WaterSteam/Junctions/Mixer2.mo:20:3-22:17:writable] Warning: Connector Ce1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
 // [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SourceQ.mo:24:3-25:52:writable] Warning: Connector C is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:784:9-784:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:851:9-851:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:1089:9-1089:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph.mo:76:3-76:60:writable] Warning: dh1satp was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph.mo:76:3-76:60:writable] Warning: dh2satp was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph_der.mo:179:3-182:49:writable] Warning: du1satp_der was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph_der.mo:179:3-182:49:writable] Warning: du2satp_der was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
 // "
 // endResult

testsuite/openmodelica/dataReconciliation/TSP_FourFlows1.mos

@@ -2484,5 +2484,12 @@ getErrorString();
 // [ThermoSysPro 3.2.0/WaterSteam/Junctions/Mixer2.mo:20:3-22:17:writable] Warning: Connector Ce1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
 // [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SourceP.mo:30:3-31:45:writable] Warning: Connector C is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
 // [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/Sink.mo:17:3-19:16:writable] Warning: Connector C is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:784:9-784:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:851:9-851:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:1089:9-1089:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph.mo:76:3-76:60:writable] Warning: dh1satp was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph.mo:76:3-76:60:writable] Warning: dh2satp was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph_der.mo:179:3-182:49:writable] Warning: du1satp_der was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph_der.mo:179:3-182:49:writable] Warning: du2satp_der was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
 // "
 // endResult

testsuite/openmodelica/dataReconciliation/TSP_FourFlows10.mos

@@ -3192,5 +3192,30 @@ getErrorString();
 // stdout            | info    | DataReconciliation Completed!
 // "
 // end SimulationResult;
-// ""
+// "[openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/Sink.mo:17:3-19:16:writable] Warning: Connector C is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SingularPressureLoss.mo:20:3-22:16:writable] Warning: Connector C1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SingularPressureLoss.mo:23:3-24:52:writable] Warning: Connector C2 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SingularPressureLoss.mo:20:3-22:16:writable] Warning: Connector C1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SingularPressureLoss.mo:23:3-24:52:writable] Warning: Connector C2 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SingularPressureLoss.mo:20:3-22:16:writable] Warning: Connector C1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SingularPressureLoss.mo:23:3-24:52:writable] Warning: Connector C2 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SingularPressureLoss.mo:20:3-22:16:writable] Warning: Connector C1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SingularPressureLoss.mo:23:3-24:52:writable] Warning: Connector C2 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/VolumeATh.mo:20:3-22:42:writable] Warning: Connector Ce1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/VolumeATh.mo:23:3-25:37:writable] Warning: Connector Ce2 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/VolumeATh.mo:26:3-28:37:writable] Warning: Connector Cs1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/VolumeATh.mo:29:3-31:43:writable] Warning: Connector Cs2 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/VolumeATh.mo:20:3-22:42:writable] Warning: Connector Ce1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/VolumeATh.mo:23:3-25:37:writable] Warning: Connector Ce2 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/VolumeATh.mo:26:3-28:37:writable] Warning: Connector Cs1 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/VolumeATh.mo:29:3-31:43:writable] Warning: Connector Cs2 is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [openmodelica/dataReconciliation/NewDataReconciliationSimpleTests/SourcePQ.mo:29:3-30:52:writable] Warning: Connector C is not balanced: The number of potential variables (4) is not equal to the number of flow variables (0).
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:784:9-784:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:851:9-851:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteam/IF97_packages.mo:1089:9-1089:27:writable] Warning: cv was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph.mo:76:3-76:60:writable] Warning: dh1satp was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph.mo:76:3-76:60:writable] Warning: dh2satp was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph_der.mo:179:3-182:49:writable] Warning: du1satp_der was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// [ThermoSysPro 3.2.0/Properties/WaterSteamSimple/prop4_Ph_der.mo:179:3-182:49:writable] Warning: du2satp_der was used before it was defined (given a value). Additional such uses may exist for the variable, but some messages were suppressed.
+// "
 // endResult