Fix the issue of returning a pointer to a local variable in data_products (#1593)

* Updated to use std::string instead for cases that ruturn const char* by referencing to a local variable.

* Updated c_str invovled check as it is never NULL and always return a null-terminated ('\0') string and also removed unnecessary conversion using c_str.

* Updated a data_products file missed last time to replace c_str check with string check.

* Updated missed parts to replace c_str check with string check.

* Updated to use C++ string comparison for std::string variables.

trick_source/data_products/DPX/APPS/FXPLOT/plot_view_node.cpp

@@ -200,19 +200,11 @@ PlotViewNode::PlotViewNode( Widget Toplevel, Widget Parent_form, DPC_plot* Plot
     curves = new XYCurve[n_curves];
 
     // X Axis label.
-    if ((const_temp_str = plot->getXLabel()) != NULL) {
+    snprintf( charbuf, sizeof(charbuf), "%s", const_temp_str );
-        snprintf( charbuf, sizeof(charbuf), "%s", const_temp_str );
-    } else {
-        charbuf[0] = '\0';
-    }
     X_label = XmStringCreateLocalized( charbuf);
 
     // Y Axis label.
-    if ((const_temp_str = plot->getYLabel()) != NULL) {
+    snprintf( charbuf, sizeof(charbuf), "%s", const_temp_str );
-        snprintf( charbuf, sizeof(charbuf), "%s", const_temp_str );
-    } else {
-        charbuf[0] = '\0';
-    }
     Y_label = XmStringCreateLocalized( charbuf);
 
     // ---------------------------

trick_source/data_products/DPX/APPS/FXPLOT/table_view_node.cpp

@@ -319,15 +319,14 @@ TableViewNode::TableViewNode( Widget Toplevel, DPC_table* Table, int Xpos, int Y
     // Print out the column heading labels.
     // ----------------------------------------------------------------
     for (colix=0; colix < n_columns ; colix++) {
-        const char *column_label = table->getColumnLabel( colix);
+        std::string column_label = table->getColumnLabel(colix);
-
+        if (column_label.empty()) {
-        if (!column_label) {
             snprintf( charbuf, sizeof(charbuf), "Column_%d", colix);
             table_text_buf = twprint( table_text_buf, &table_buf_size, &table_insertion_pos,
                                       column_heading_format[colix], charbuf);
         } else {
             table_text_buf = twprint( table_text_buf, &table_buf_size, &table_insertion_pos,
-                                      column_heading_format[colix], column_label);
+                                      column_heading_format[colix], column_label.c_str());
         }
     }
     table_text_buf = twprint( table_text_buf, &table_buf_size, &table_insertion_pos, (char *)"\n");

trick_source/data_products/DPX/APPS/GXPLOT/gp_view_plot_node.cpp

@@ -124,11 +124,11 @@ void GPViewPlotNode::finalize() {
      *          So, check the return value before making the assignment.
      */
     plot_title      = (plot->getTitle()) ?  plot->getTitle() : tmp_stream.str();
-    plot_x_label    = (plot->getXLabel()) ?  plot->getXLabel() : "";
+    plot_x_label    = plot->getXLabel();
     plot_x_scale    = (plot->getAttribute("x_scale")) ?  plot->getAttribute("x_scale") : "";
     plot_x_min_rng  = (plot->getAttribute("xmin")) ?  plot->getAttribute("xmin") : "";
     plot_x_max_rng  = (plot->getAttribute("xmax")) ?  plot->getAttribute("xmax") : "";
-    plot_y_label    = (plot->getYLabel()) ?  plot->getYLabel() : "";
+    plot_y_label    = plot->getYLabel();
     plot_y_format   = (plot->getAttribute("format")) ?  plot->getAttribute("format") : "";
     plot_y_scale    = (plot->getAttribute("y_scale")) ?  plot->getAttribute("y_scale") : "";
     plot_y_min_rng  = (plot->getAttribute("ymin")) ?  plot->getAttribute("ymin") : "";

trick_source/data_products/DPX/DPC/DPC_UnitConvDataStream.cpp

@@ -12,7 +12,7 @@ DPC_UnitConvDataStream::DPC_UnitConvDataStream(DataStream* ds, const char *ToUni
     ut_unit * to = NULL ;
     ut_unit * from = NULL ;
     
-    const char * recorded_units = ds->getUnit().c_str();
+    std::string recorded_units = ds->getUnit();
 
     source_ds = ds;
 
@@ -24,7 +24,7 @@ DPC_UnitConvDataStream::DPC_UnitConvDataStream(DataStream* ds, const char *ToUni
     // If the user has specified a units conversion and those units are valid ...
     if ( to != NULL ) {
         // If the recorded data file doesn't contain the units in which the data is recorded ...
-        if ((recorded_units == NULL) || (strcmp(recorded_units,"") == 0)) {
+        if (recorded_units.empty()) {
             // If the user didn't give us a hint as to what the units are (using var@from_units) ...
             if ((FromUnitsHint == NULL) || (strcmp(FromUnitsHint,"") == 0)) {
                 // set the from units to the same as the to units.
@@ -47,7 +47,7 @@ DPC_UnitConvDataStream::DPC_UnitConvDataStream(DataStream* ds, const char *ToUni
             }
         } else { // the recorded data file does "know" the units in which the data was recorded,
             // so those will be the units that we convert from.
-            from = ut_parse(u_system, recorded_units, UT_ASCII) ;
+            from = ut_parse(u_system, recorded_units.c_str(), UT_ASCII) ;
             if ( !from ) {
                 std::cerr << "ERROR: Unable to to perform units conversion because the"
                           << " units in the data recording file appear to be corrupt."
@@ -72,7 +72,7 @@ DPC_UnitConvDataStream::DPC_UnitConvDataStream(DataStream* ds, const char *ToUni
         }
     } else { // The user has not specified a units conversion or the units were not valid.
         // If the recorded data file doesn't contain the units in which the data is recorded ...
-        if ((recorded_units == NULL) || (strcmp(recorded_units,"") == 0)) {
+        if (recorded_units.empty()) {
             // If the user didn't give us a hint as to what the units are (using var@from_units) ...
             if ((FromUnitsHint == NULL) || (strcmp(FromUnitsHint,"") == 0)) {
                 cf = cv_get_trivial() ;

trick_source/data_products/DPX/DPC/DPC_curve.hh

@@ -39,7 +39,7 @@ public:
     /**
      * Return the name of the X variable.
      */
-    const char *getXVarShortName() {
+    std::string getXVarShortName() {
         return( x_var->getShortName() );
     };
 
@@ -53,7 +53,7 @@ public:
     /**
      * Return the name of the Y variable.
      */
-    const char *getYVarShortName() {
+    std::string getYVarShortName() {
         return( y_var->getShortName() );
     };
 

trick_source/data_products/DPX/DPC/DPC_plot.hh

@@ -78,16 +78,16 @@ public:
     }
 
     /**
-     * Return the X-axis label of the plot, which may be NULL.
+     * Return the X-axis label of the plot, which may be empty.
      */
-    const char *getXLabel() {
+    std::string getXLabel() {
         return( relation->getXAxisLabel());
     }
 
     /**
-     * Return the Y-axis label of the plot, which may be NULL.
+     * Return the Y-axis label of the plot, which may be empty.
      */
-    const char *getYLabel() {
+    std::string getYLabel() {
         return( relation->getYAxisLabel());
     }
 

trick_source/data_products/DPX/DPC/DPC_std_curve.cpp

@@ -106,9 +106,9 @@ DPC_std_curve::DPC_std_curve(
                                                 Time_constraints );
             if (ds[0] != NULL) {
 
-                const char* ds_units = ds[0]->getUnit().c_str();
+                std::string ds_units = ds[0]->getUnit();
 
-                y_actual_units = strdup(ds_units);
+                y_actual_units = strdup(ds_units.c_str());
 
                 // Tell our DataStream to start at the beginning.
                 ds[0]->begin();

trick_source/data_products/DPX/DPC/DPC_table.cpp

@@ -194,12 +194,12 @@ int DPC_table::getNumColumns() {
 }
 
 // MEMBER FUNCTION
-const char *DPC_table::getColumnLabel(unsigned int index) {
+std::string DPC_table::getColumnLabel(unsigned int index) {
     DPM_column *column = table_spec->getColumn( index );
     if ( column->getLabel() != NULL) {
         return( column->getLabel());
     } else {
-        return( column->getVar()->getShortName());
+        return( column->getVar()->getShortName() );
     }
 }
 

trick_source/data_products/DPX/DPC/DPC_table.hh

@@ -53,9 +53,9 @@ public:
   int getNumColumns();
 
   /**
-   * Return the Label (which may be NULL) of the of the indicated column.
+   * Return the Label (which may be empty) of the of the indicated column.
    */
-  const char *getColumnLabel(unsigned int index);
+  std::string getColumnLabel(unsigned int index);
 
   /**
    * Return the name of the variable for the indicated column.

trick_source/data_products/DPX/DPM/DPM_curve.cpp

@@ -231,57 +231,54 @@ const char * DPM_curve::getZVarName(unsigned int case_index) {
 }
 
 // MEMBER FUNCTION
-const char * DPM_curve::getXCommonName() {
+std::string DPM_curve::getXCommonName() {
+
+  std::string candidate_label;
   
-  const char *candidate_label;
-  const char *short_name;
   int n_vars, i;
 
   candidate_label = x_varcase_list[0]->getShortName();
   n_vars = (int)x_varcase_list.size();
   for (i=1; i<n_vars; i++) {
-     short_name = x_varcase_list[i]->getShortName();
+     if (candidate_label != x_varcase_list[i]->getShortName()) {
-     if (strcmp( candidate_label, short_name) != 0 ) {
+        return ("");
-        return (NULL);
      }
   }
-  return ( candidate_label);
+  return (candidate_label);
 }
 
 // MEMBER FUNCTION
-const char * DPM_curve::getYCommonName() {
+std::string DPM_curve::getYCommonName() {
+
+  std::string candidate_label;
   
-  const char *candidate_label;
-  const char *short_name;
   int n_vars, i;
 
   candidate_label = y_varcase_list[0]->getShortName();
   n_vars = (int)y_varcase_list.size();
   for (i=1; i<n_vars; i++) {
-     short_name = y_varcase_list[i]->getShortName();
+     if (candidate_label != y_varcase_list[i]->getShortName()) {
-     if (strcmp( candidate_label, short_name) != 0 ) {
+        return ("");
-        return (NULL);
      }
   }
   return ( candidate_label);
 }
 
 // MEMBER FUNCTION
-const char * DPM_curve::getZCommonName() {
+std::string DPM_curve::getZCommonName() {
+
+  std::string candidate_label;
   
-  const char *candidate_label;
-  const char *short_name;
   int n_vars, i;
 
   candidate_label = z_varcase_list[0]->getShortName();
   n_vars = (int)z_varcase_list.size();
   for (i=1; i<n_vars; i++) {
-     short_name = z_varcase_list[i]->getShortName();
+     if (candidate_label != z_varcase_list[i]->getShortName()) {
-     if (strcmp( candidate_label, short_name) != 0 ) {
+        return ("");
-        return (NULL);
      }
   }
-  return ( candidate_label);
+  return (candidate_label);
 }
 
 // MEMBER FUNCTION

trick_source/data_products/DPX/DPM/DPM_curve.hh

@@ -69,17 +69,17 @@ public:
   /**
    *
    */
-  const char * getXCommonName();
+  std::string getXCommonName();
 
   /**
    *
    */
-  const char * getYCommonName();
+  std::string getYCommonName();
 
   /**
    *
    */
-  const char * getZCommonName();
+  std::string getZCommonName();
 
   /**
    * Output an xml representation of DPM_curve.

trick_source/data_products/DPX/DPM/DPM_relation.cpp

@@ -148,29 +148,26 @@ int DPM_relation::NumberOfAxes() {
 }
 
 // MEMBER FUNCTION
-const char * DPM_relation::getXAxisLabel() {
+std::string DPM_relation::getXAxisLabel() {
-  const char * candidate_label;
+  std::string candidate_label;
-  const char * short_name;
+  
   int n_curves, i;
 
   if (xaxis) {
       candidate_label = xaxis->getLabel();
   } else {
-      candidate_label = NULL;
+      candidate_label = "";
   }
   // If an Y-Axis label wasn't supplied, see if there is a common
   // variable name that will serve as a label.
-  if (candidate_label == NULL) {
+  if (candidate_label == "") {
-      if (( candidate_label = curve_list[0]->getXCommonName() ) == NULL) {
+      if (( candidate_label = curve_list[0]->getXCommonName() ) == "") {
-          return (NULL);
+          return ("");
       }
       n_curves = (int)curve_list.size();
       for (i=1; i<n_curves; i++) {
-          if (( short_name = curve_list[i]->getXCommonName() ) == NULL ) {
+          if ( curve_list[i]->getXCommonName().empty() || candidate_label != curve_list[i]->getXCommonName()) {
-               return (NULL);
+               return ("");
-          }
-          if (strcmp( candidate_label, short_name) != 0 ) {
-               return (NULL);
           } 
       }
   }
@@ -178,29 +175,26 @@ const char * DPM_relation::getXAxisLabel() {
 }
 
 // MEMBER FUNCTION
-const char * DPM_relation::getYAxisLabel() {
+std::string DPM_relation::getYAxisLabel() {
-  const char * candidate_label;
+  std::string candidate_label;
-  const char * short_name;
+  
   int n_curves, i;
 
   if (yaxis) {
       candidate_label = yaxis->getLabel();
   } else {
-      candidate_label = NULL;
+      candidate_label = "";
   }
   // If an Y-Axis label wasn't supplied, see if there is a common
   // variable name that will serve as a label.
-  if (candidate_label == NULL) {
+  if (candidate_label == "") {
-      if (( candidate_label = curve_list[0]->getYCommonName() ) == NULL) {
+      if (( candidate_label = curve_list[0]->getYCommonName() ) == "") {
-          return (NULL);
+          return ("");
       }
       n_curves = (int)curve_list.size();
       for (i=1; i<n_curves; i++) {
-          if (( short_name = curve_list[i]->getYCommonName() ) == NULL ) {
+          if (curve_list[i]->getYCommonName().empty() || candidate_label != curve_list[i]->getYCommonName()) {
-               return (NULL);
+               return ("");
-          }
-          if (strcmp( candidate_label, short_name) != 0 ) {
-               return (NULL);
           } 
       }
   }
@@ -208,29 +202,26 @@ const char * DPM_relation::getYAxisLabel() {
 }
 
 // MEMBER FUNCTION
-const char * DPM_relation::getZAxisLabel() {
+std::string DPM_relation::getZAxisLabel() {
-  const char * candidate_label;
+  std::string candidate_label;
-  const char * short_name;
+  
   int n_curves, i;
 
   if (zaxis) {
       candidate_label = zaxis->getLabel();
   } else {
-      candidate_label = NULL;
+      candidate_label = "";
   }
   // If an Z-Axis label wasn't supplied, see if there is a common
   // variable name that will serve as a label.
-  if (candidate_label == NULL) {
+  if (candidate_label == "") {
-      if (( candidate_label = curve_list[0]->getZCommonName() ) == NULL) {
+      if (( candidate_label = curve_list[0]->getZCommonName() ) == "") {
-          return (NULL);
+          return ("");
       }
       n_curves = (int)curve_list.size();
       for (i=1; i<n_curves; i++) {
-          if (( short_name = curve_list[i]->getZCommonName() ) == NULL ) {
+          if (curve_list[i]->getZCommonName().empty() || candidate_label != curve_list[i]->getZCommonName()) {
-               return (NULL);
+               return ("");
-          }
-          if (strcmp( candidate_label, short_name) != 0 ) {
-               return (NULL);
           } 
       }
   }

trick_source/data_products/DPX/DPM/DPM_relation.hh

@@ -53,9 +53,9 @@ public:
   /**
    *
    */
-  const char * getXAxisLabel();
+  std::string getXAxisLabel();
-  const char * getYAxisLabel();
+  std::string getYAxisLabel();
-  const char * getZAxisLabel();
+  std::string getZAxisLabel();
 
   /**
    *

trick_source/data_products/DPX/DPM/DPM_var.cpp

@@ -40,7 +40,7 @@ const char* DPM_var::getName() {
   return ( (const char*)name );
 }
 
-const char* DPM_var::getShortName() {
+std::string DPM_var::getShortName() {
     char *p;
 
     std::string::size_type idx ;
@@ -103,7 +103,7 @@ const char* DPM_var::getShortName() {
         } else {
             combinedName += " - " + paramName2;
         }
-        return combinedName.c_str();
+        return combinedName;
     }
 }
 

trick_source/data_products/DPX/DPM/DPM_var.hh

@@ -43,7 +43,7 @@ class DPM_var:public DPM_component {
      * Return the part of the variable name right of the last
      * period or the name if there are no periods.
      */
-    const char     *getShortName();
+    std::string     getShortName();
 
     /**
      * Output an xml representation of DPM_var.

trick_source/data_products/DPX/TESTING/DPC_TEST/test_view.cpp

@@ -93,7 +93,7 @@ DPV_pointer test_view::create_table_view( DPV_pointer parent_data,
   cout << "Number of Columns : " << n_columns << endl;
 
   for (colix=0; colix < n_columns ; colix++) {
-    const char *col_label = table->getColumnLabel( colix);
+    const char *col_label = table->getColumnLabel( colix).c_str();
     const char *var_name = table->getColumnVarName( colix);
     const char *col_units = table->getColumnUnits( colix);
     const char *format = table->getColumnAttribute( colix,"format");

trick_source/data_products/DPX/test/unit_test/test_view.cpp

@@ -138,7 +138,7 @@ DPV_pointer Test_view::render_table( DPV_pointer parent_data, DPC_table  *table)
   	s << "Number of Columns: " << n_columns << std::endl;
 
   	for (colix=0; colix < n_columns ; colix++) {
-    	if ((temp_cstr = table->getColumnLabel(colix)) != NULL) {
+    	if ((temp_cstr = table->getColumnLabel(colix).c_str())[0] != '\0') {
       		s << "Column Label [" << colix << "]: " << temp_cstr << std::endl;
     	}
     	if ((temp_cstr = table->getColumnVarName(colix)) != NULL) {