Fix integer packing in C code generation.

- Pack integers into new arrays instead of packing in place, to avoid
  segfaults when passing integer array literals to external functions.

Belonging to [master]:
  - OpenModelica/OMCompiler#2994

Compiler/Template/CodegenCFunctions.tpl

@@ -2197,7 +2197,9 @@ template extFunCallVardecl(SimExtArg arg, Text &varDecls, Text &auxFunction, Boo
   case SIMEXTARG(isInput = true, isArray = true, type_ = ty, cref = c) then
     match expTypeShort(ty)
     case "integer" then
-      'pack_integer_array(&<%contextCref(c,contextFunction,&auxFunction)%>);<%\n%>'
+      let var_name = '<%contextCref(c, contextFunction, &auxFunction)%>'
+      let &varDecls += 'integer_array <%var_name%>_packed;<%\n%>'
+      'pack_alloc_integer_array(&<%var_name%>, &<%var_name%>_packed);<%\n%>'
     else ""
   case SIMEXTARG(isInput = false, isArray = true, type_ = ty, cref = c) then
     match expTypeShort(ty)
@@ -2223,7 +2225,7 @@ template extFunCallVardecl(SimExtArg arg, Text &varDecls, Text &auxFunction, Boo
     else
       let &varDecls += '<%extType(ty,true,false,false)%> <%extVarName(c)%>;<%\n%>'
       <<
-      <%extVarName(c)%> = (<%extType(ty,true,false,false)%>)<%match ty case T_COMPLEX(complexClassType=RECORD(__)) then "&" else ""%><%contextCref(c,contextFunction,&auxFunction)%>;
+      <%extVarName(c)%> = (<%extType(ty,true,false,false)%>)<%match ty case T_COMPLEX(complexClassType=RECORD(__)) then "&" else ""%><%contextCref(c,contextFunction,&auxFunction)%>;<%\n%>
       >>
   case SIMEXTARG(outputIndex=oi, isArray=false, type_=ty, cref=c) then
     match oi case 0 then
@@ -2319,20 +2321,17 @@ template extFunCallVarcopy(SimExtArg arg, Text &auxFunction)
  "Helper to extFunCall."
 ::=
 match arg
-case SIMEXTARG(isInput = true, isArray = true, type_ = ty, cref = c) then
-  // Inputs that have been packed should be unpacked after the external call.
-  match expTypeShort(ty)
-  case "integer" then
-  'unpack_integer_array(&<%contextCref(c,contextFunction,&auxFunction)%>);'
-  else ""
 case SIMEXTARG(outputIndex=0) then ""
-case SIMEXTARG(outputIndex=oi, isArray=true, cref=c, type_=ty) then
+case SIMEXTARG(outputIndex=oi, isInput=isInput, isArray=true, cref=c, type_=ty) then
+  let var_name = contextCref(c, contextFunction, &auxFunction)
   match expTypeShort(ty)
-  case "integer" then
-  'unpack_integer_array(&<%contextCref(c,contextFunction,&auxFunction)%>);'
-  case "string" then
-  'unpack_string_array(&<%contextCref(c,contextFunction,&auxFunction)%>, <%contextCref(c,contextFunction,&auxFunction)%>_c89);'
-  else ""
+    case "integer" then
+      if isInput then
+        'unpack_copy_integer_array(&<%var_name%>_packed, &<%var_name%>);'
+      else
+        'unpack_integer_array(&<%var_name%>);'
+    case "string" then 'unpack_string_array(&<%var_name%>, <%var_name%>_c89);'
+    else ""
 case SIMEXTARG(outputIndex=oi, isArray=false, type_=ty, cref=c) then
     let cr = '<%extVarName(c)%>'
     <<
@@ -2365,11 +2364,13 @@ template extArg(SimExtArg extArg, Text &preExp, Text &varDecls, Text &auxFunctio
  "Helper to extFunCall."
 ::=
   match extArg
-  case SIMEXTARG(cref=c, outputIndex=oi, isArray=true, type_=t) then
+  case SIMEXTARG(cref=c, outputIndex=oi, isArray=true, type_=t, isInput=isInput) then
     let name = contextCref(c,contextFunction,&auxFunction)
     let shortTypeStr = expTypeShort(t)
     let &varDecls += 'void *<%name%>_c89;<%\n%>'
-    let &preExp += '<%name%>_c89 = (void*) data_of_<%shortTypeStr%>_c89_array(&(<%name%>));<%\n%>'
+    //let arg_name = match shortTypeStr case "integer" then '<%name%>_packed' else name
+    let arg_name = if isInput then (match shortTypeStr case "integer" then '<%name%>_packed' else name) else name
+    let &preExp += '<%name%>_c89 = (void*) data_of_<%shortTypeStr%>_c89_array(&(<%arg_name%>));<%\n%>'
     '(<%extType(t,isInput,true,false)%>) <%name%>_c89'
   case SIMEXTARG(cref=c, isInput=ii, outputIndex=0, type_=t) then
     let cr = match t case T_STRING(__) then contextCref(c,contextFunction,&auxFunction) else extVarName(c)

SimulationRuntime/c/util/integer_array.c

@@ -1600,6 +1600,56 @@ void unpack_integer_array(integer_array_t *a)
   }
 }
 
+/* Returns a modelica_integer array that can be treated as an int array. If the
+ * size of int and modelica_integer is the same this means simply returning the
+ * given array, but if int is smaller than modelica_integer a new array is
+ * allocated and filled with the data from given array as if it was an int array.
+ *
+ * I.e. if int is 32 bit and modelica_integer is 64 bit then the data will be
+ * packed into the first half of the new array.
+ *
+ * The case where int is larger than modelica_integer is not implemented. */
+void pack_alloc_integer_array(integer_array_t *a, integer_array_t *dest)
+{
+  if (sizeof(int) == sizeof(modelica_integer)) {
+    *dest = *a;
+  } else {
+    /* We only handle the case where int is smaller than modelica_integer. */
+    omc_assert_macro(sizeof(int) < sizeof(modelica_integer));
+
+    /* Allocate a new array. */
+    clone_integer_array_spec(a, dest);
+    alloc_integer_array_data(dest);
+
+    /* Pretend that the new array is an int array and fill it with the values
+     * from the given array. */
+    int *int_data = (int*)dest->data;
+    long i;
+    size_t n = base_array_nr_of_elements(*a);
+
+    for (i = 0; i < n; ++i) {
+      int_data[i] = (int)integer_get(*a, i);
+    }
+  }
+}
+
+/* Unpacks an integer_array that was packed with pack_integer_array into the
+ * destination array. If packing hasn't been done, i.e. if the size of int and
+ * modelica_integer is the same, then the function does nothing since both the
+ * source and destination is assumed to be the same array. */
+void unpack_copy_integer_array(const integer_array_t *a, integer_array_t *dest)
+{
+  if(sizeof(int) != sizeof(modelica_integer)) {
+    long i;
+    const int * int_data = (const int*)a->data;
+    long n = (long)base_array_nr_of_elements(*a);
+
+    for(i = n - 1; i >= 0; --i) {
+      integer_set(dest, i, int_data[i]);
+    }
+  }
+}
+
 void convert_alloc_integer_array_to_f77(const integer_array_t * a,
                                         integer_array_t* dest)
 {

SimulationRuntime/c/util/integer_array.h

@@ -279,6 +279,8 @@ extern void convert_alloc_integer_array_from_f77(const integer_array_t * a,
 
 void pack_integer_array(integer_array_t *a);
 void unpack_integer_array(integer_array_t *a);
+void pack_alloc_integer_array(integer_array_t *a, integer_array_t *dest);
+void unpack_copy_integer_array(const integer_array_t *a, integer_array_t *dest);
 
 /* Note: data_of_integer_array converts from integer_array to int*, for external functions only */
 static inline int* data_of_integer_array(const integer_array_t *a)