NOT YET PART OF SEAMONKEY:

* initial pass at handling the update of interface indices.

xpcom/libxpt/tools/xpt_link.c

@@ -32,15 +32,33 @@
 #endif
 
 /* Forward declarations. */
+typedef struct fixElement fixElement;
 static int compare_IDEs_by_IID(const void *ap, const void *bp);
 static int compare_IDEs_by_name(const void *ap, const void *bp);
+static int compare_IDEs_by_name_space(const void *ap, const void *bp);
+static int compare_fixElements_by_name(const void *ap, const void *bp);
 static int compare_IIDs(const void *ap, const void *bp);
+PRBool shrink_IDE_array(XPTInterfaceDirectoryEntry *ide, 
+                        int element_to_delete, int num_interfaces);
+PRBool update_fix_array(fixElement *deleted, int new_index);
+static int get_new_index(const fixElement *fix, int num_elements,
+                         int target_file, int target_interface);
 PRBool copy_IDE(XPTInterfaceDirectoryEntry *from, 
                 XPTInterfaceDirectoryEntry *to);
 static void xpt_dump_usage(char *argv[]); 
 
+struct fixElement {
+    nsID *iid;
+    char* name;
+    int file_num;
+    int interface_num;
+    PRBool is_deleted;
+    int index;
+};
+
 /* Global variables. */
-int numberOfInterfaces = 0;
+int trueNumberOfInterfaces = 0;
+int totalNumberOfInterfaces = 0;
 
 int 
 main(int argc, char **argv)
@@ -49,13 +67,16 @@ main(int argc, char **argv)
     XPTCursor curs, *cursor = &curs;
     XPTHeader *header;
     XPTInterfaceDirectoryEntry *newIDE, *IDE_array;
+    XPTInterfaceDescriptor *id;
+    XPTTypeDescriptor *td;
     XPTAnnotation *ann;
     uint32 header_sz, len;
     struct stat file_stat;
     size_t flen = 0;
     char *head, *data, *whole;
     FILE *in, *out;
-    int i,j;
+    fixElement *newFix, *fix_array;
+    int i,j,l;
     int k = 0;
 
     if (argc < 3) {
@@ -107,16 +128,24 @@ main(int argc, char **argv)
                 return 1;
             }                                        
             
-            numberOfInterfaces += header->num_interfaces;
+            totalNumberOfInterfaces += header->num_interfaces;
             if (k == 0) {
-                IDE_array = PR_CALLOC(numberOfInterfaces * sizeof(XPTInterfaceDirectoryEntry));
+                IDE_array = PR_CALLOC(totalNumberOfInterfaces * sizeof(XPTInterfaceDirectoryEntry));
+                fix_array = PR_CALLOC(totalNumberOfInterfaces * sizeof(fixElement));
             } else {
-                newIDE = PR_REALLOC(IDE_array, numberOfInterfaces * sizeof(XPTInterfaceDirectoryEntry));
+                newIDE = PR_REALLOC(IDE_array, totalNumberOfInterfaces * sizeof(XPTInterfaceDirectoryEntry));
+                newFix = PR_REALLOC(fix_array, totalNumberOfInterfaces * sizeof(fixElement));
+
                 if (!newIDE) {
                     perror("FAILED: PR_REALLOC of IDE_array");
                     return 1;
                 }
+                if (!newFix) {
+                    perror("FAILED: PR_REALLOC of newFix");
+                    return 1;
+                }
                 IDE_array = newIDE;
+                fix_array = newFix;
             }
             
             for (j=0; j<header->num_interfaces; j++) {
@@ -125,6 +154,12 @@ main(int argc, char **argv)
                     perror("FAILED: 1st copying of IDE");
                     return 1;
                 }
+                fix_array[k].iid = &IDE_array[k].iid;
+                fix_array[k].name = IDE_array[k].name;
+                fix_array[k].file_num = i-2;
+                fix_array[k].interface_num = j+1;
+                fix_array[k].is_deleted = PR_FALSE;
+
                 k++;
             }
             
@@ -140,16 +175,180 @@ main(int argc, char **argv)
             return 1;
         }
     }
- 
+
+    /* Sort both IDE_array and fix_array by name so we can check for 
+     * name_space::name collisions. 
+     */
     qsort(IDE_array, 
-          numberOfInterfaces, 
+          totalNumberOfInterfaces, 
+          sizeof(XPTInterfaceDirectoryEntry), 
+          compare_IDEs_by_name);
+
+    qsort(fix_array, 
+          totalNumberOfInterfaces, 
+          sizeof(fixElement), 
+          compare_fixElements_by_name);
+
+    /* Iterate through fix_array now that it is in its final form (sorted)
+     * and set the index. Index is i+1 because index 0 is reserved for
+     * the special case (no parent interface).
+     */
+    for (i=0; i<totalNumberOfInterfaces; i++) {
+        fix_array[k].index = i+1;
+    }
+
+    /* trueNumberOfInterfaces == number of interfaces left after deletions
+     * are made. Initialize it here to be the same as the total number of
+     * interfaces we'ce encountered thus far.
+     */
+    trueNumberOfInterfaces = totalNumberOfInterfaces;
+
+    /* Iterate through the sorted interfaces. Start at one so we don't 
+     * accidentally walk off the end of the array.
+     */
+    i = 1;
+    while (i != trueNumberOfInterfaces) {
+        
+        /* Check for name_space::name collision. 
+         */
+        if (compare_IDEs_by_name(&IDE_array[i-1], &IDE_array[i]) == 0 && 
+            compare_IDEs_by_name_space(&IDE_array[i-1], &IDE_array[i]) == 0) {
+            
+            /* If one of the interfaces is unresolved, delete that one 
+             * preferentailly.
+             */
+            if (!&IDE_array[i-1].iid) {
+                /* Shrink the IDE_array to delete the duplicate interface.
+                 */
+                if (!shrink_IDE_array(IDE_array, 
+                                      i-1, 
+                                      trueNumberOfInterfaces)) {
+                    perror("FAILED: shrink_IDE_array");
+                    return 1;
+                }
+                /* Update the fix_array so that the index that corresponds
+                 * to the just-deleted IDE now points to the surviving IDE
+                 * of the same name. Indices are one-based, so the second 
+                 * argument is passed as i+1 (instead of i).
+                 */
+                update_fix_array(&fix_array[i-1], i+1);
+                /* Decrement the true number of interfaces since we just
+                 * deleted one. There's more than one way to get out of
+                 * this loop.
+                 */
+                trueNumberOfInterfaces--;
+            } else {
+                if (!&IDE_array[i].iid || 
+                    (compare_IIDs(&IDE_array[i-1].iid, &IDE_array[i].iid) == 0)) {
+                    /* Shrink the IDE_array to delete the duplicate interface.
+                     */
+                    if (!shrink_IDE_array(IDE_array, 
+                                          i, 
+                                          trueNumberOfInterfaces)) {
+                        perror("FAILED: shrink_IDE_array");
+                        return 1;
+                    }
+                    /* Update the fix_array so that the index that corresponds
+                     * to the just-deleted IDE now points to the surviving IDE
+                     * of the same name. Indices are one-based, so the second 
+                     * argument is passed as i (instead of i-1).
+                     */
+                    update_fix_array(&fix_array[i], i);
+                    /* Decrement the true number of interfaces since we just
+                     * deleted one. There's more than one way to get out of
+                     * this loop.
+                     */
+                    trueNumberOfInterfaces--;
+                }
+            }
+            
+        } else {
+            /* Only increment if there was no name_space::name collision.
+             */
+            i++;
+        }
+    }
+
+    /* Iterate through the remaining interfaces. There's some magic here - 
+     * we walk fix_array at the same time skipping over ones that have 
+     * been deleted. This should work correctly since we only ever delete
+     * things in a linear manner.
+     */
+    for (i=0,j=0; 
+         i<trueNumberOfInterfaces && j<totalNumberOfInterfaces; 
+         i++,j++) {
+        
+        /* Define id to save some keystrokes.
+         */
+        id = IDE_array[i].interface_descriptor;
+        /* Skip ahead in fix_array until past the deleted elements.
+         */
+        while (fix_array[j].is_deleted) {
+            j++;
+        }
+        /* Fix parent_interface first.
+         */
+        if (id->parent_interface != 0) {
+            id->parent_interface = 
+                get_new_index(fix_array, totalNumberOfInterfaces,
+                              fix_array[j].file_num, id->parent_interface);
+        }
+        /* Iterate through the method descriptors looking for params of
+         * type TD_INTERFACE_TYPE.
+         */
+        for (k=0; k<id->num_methods; k++) {
+            /* Cycle through the params first.
+             */
+            for (l=0; l<id->method_descriptors[k].num_args; l++) {
+                /* Define td to save some keystrokes.
+                 */
+                td = &id->method_descriptors[k].params[l].type;
+                if (XPT_TDP_TAG(td->prefix) == TD_INTERFACE_TYPE) {
+                    td->type.interface = 
+                        get_new_index(fix_array, 
+                                      totalNumberOfInterfaces,
+                                      fix_array[j].file_num, 
+                                      td->type.interface);
+                }                                                
+            }
+
+            /* Check the result param too. Define td again to save 
+             * some keystrokes.
+             */
+            td = &id->method_descriptors[k].result->type;
+            if (XPT_TDP_TAG(td->prefix) == TD_INTERFACE_TYPE) {
+                td->type.interface = 
+                    get_new_index(fix_array, totalNumberOfInterfaces,
+                                  fix_array[j].file_num, td->type.interface);
+            }                
+        }
+    } 
+
+    /* Sort the IDE_array by IID for output to xpt file.
+     */
+    qsort(IDE_array, 
+          trueNumberOfInterfaces, 
           sizeof(XPTInterfaceDirectoryEntry), 
           compare_IDEs_by_IID);
 
-    header = XPT_NewHeader(numberOfInterfaces);
+    /* Iterate through the array quickly looking for duplicate IIDS.
+     * This shouldn't happen, i.e. is a failure condition, so bail
+     * if we find a duplicate. If we have more than one entry, start 
+     * at one so we don't accidentally grep the ether.
+     */
+    if (trueNumberOfInterfaces>1) {
+        for (i=1; i<trueNumberOfInterfaces; i++) {
+            if (compare_IDEs_by_IID(&IDE_array[i-1], &IDE_array[i]) == 0) {
+                perror("Error: Whoa, Nellie! You've got duplicate IIDs.");
+                return 1;
+            }
+        }
+    }
+
+    header = XPT_NewHeader(trueNumberOfInterfaces);
     ann = XPT_NewAnnotation(XPT_ANN_LAST, NULL, NULL);
     header->annotations = ann;
-    for (i=0; i<numberOfInterfaces; i++) {
+    for (i=0; i<trueNumberOfInterfaces; i++) {
         if (!copy_IDE(&IDE_array[i], &header->interface_directory[i])) {
             perror("FAILED: 2nd copying of IDE");
             return 1;
@@ -215,6 +414,24 @@ compare_IDEs_by_name(const void *ap,
     
     return strcmp(ide1->name, ide2->name);
 }
+
+static int 
+compare_IDEs_by_name_space(const void *ap,
+                           const void *bp)
+{
+    const XPTInterfaceDirectoryEntry *ide1 = ap, *ide2 = bp;
+    
+    return strcmp(ide1->name_space, ide2->name_space);
+}
+
+static int 
+compare_fixElements_by_name(const void *ap,
+                    const void *bp)
+{
+    const fixElement *fix1 = ap, *fix2 = bp;
+    
+    return strcmp(fix1->name, fix2->name);
+}
     
 static int
 compare_IIDs(const void *ap, const void *bp)
@@ -233,6 +450,59 @@ compare_IIDs(const void *ap, const void *bp)
 #undef COMPARE
 }
 
+PRBool 
+shrink_IDE_array(XPTInterfaceDirectoryEntry *ide, int element_to_delete,
+                    int num_interfaces)
+{
+    int i;
+
+    if (element_to_delete >= num_interfaces) {
+        return PR_FALSE;
+    }
+
+    for (i=element_to_delete+1; i<num_interfaces; i++) {
+        if (!copy_IDE(&ide[i], &ide[i-1])) {
+            return PR_FALSE;
+        }
+    }
+
+    return PR_TRUE;
+}
+
+/* update_fix_array marks a fixElement as deleted and updates the index 
+ *  marker. Deleted elements are not used for comparison purposes with 
+ * IDE_array. There only purpose is to set the interface index (if 
+ * necessary) for id->parent_interfaces and TypeDescriptors once the IDEs 
+ * are sorted and pruned. 
+ */
+PRBool 
+update_fix_array(fixElement *deleted, int new_index) 
+{
+    deleted->is_deleted = PR_TRUE;
+    deleted->index = new_index;
+    
+    return PR_TRUE;
+}
+
+/* get_new_index returns the new interface index by walking the fix_array
+ * until the file_num and interface_num match the target values. Indices 
+ * are one-based; zero represents the special case (no parent interface). 
+ */
+static int 
+get_new_index(const fixElement *fix, int num_elements, 
+              int target_file, int target_interface) 
+{
+    int i;
+    
+    for (i=0; i<num_elements; i++) { 
+        if (fix[i].file_num == target_file &&
+            fix[i].interface_num == target_interface)
+            return fix[i].index;
+    }
+    
+    return 0;
+}
+
 PRBool
 copy_IDE(XPTInterfaceDirectoryEntry *from, XPTInterfaceDirectoryEntry *to) 
 {

xpcom/typelib/xpt/tools/xpt_link.c

@@ -32,15 +32,33 @@
 #endif
 
 /* Forward declarations. */
+typedef struct fixElement fixElement;
 static int compare_IDEs_by_IID(const void *ap, const void *bp);
 static int compare_IDEs_by_name(const void *ap, const void *bp);
+static int compare_IDEs_by_name_space(const void *ap, const void *bp);
+static int compare_fixElements_by_name(const void *ap, const void *bp);
 static int compare_IIDs(const void *ap, const void *bp);
+PRBool shrink_IDE_array(XPTInterfaceDirectoryEntry *ide, 
+                        int element_to_delete, int num_interfaces);
+PRBool update_fix_array(fixElement *deleted, int new_index);
+static int get_new_index(const fixElement *fix, int num_elements,
+                         int target_file, int target_interface);
 PRBool copy_IDE(XPTInterfaceDirectoryEntry *from, 
                 XPTInterfaceDirectoryEntry *to);
 static void xpt_dump_usage(char *argv[]); 
 
+struct fixElement {
+    nsID *iid;
+    char* name;
+    int file_num;
+    int interface_num;
+    PRBool is_deleted;
+    int index;
+};
+
 /* Global variables. */
-int numberOfInterfaces = 0;
+int trueNumberOfInterfaces = 0;
+int totalNumberOfInterfaces = 0;
 
 int 
 main(int argc, char **argv)
@@ -49,13 +67,16 @@ main(int argc, char **argv)
     XPTCursor curs, *cursor = &curs;
     XPTHeader *header;
     XPTInterfaceDirectoryEntry *newIDE, *IDE_array;
+    XPTInterfaceDescriptor *id;
+    XPTTypeDescriptor *td;
     XPTAnnotation *ann;
     uint32 header_sz, len;
     struct stat file_stat;
     size_t flen = 0;
     char *head, *data, *whole;
     FILE *in, *out;
-    int i,j;
+    fixElement *newFix, *fix_array;
+    int i,j,l;
     int k = 0;
 
     if (argc < 3) {
@@ -107,16 +128,24 @@ main(int argc, char **argv)
                 return 1;
             }                                        
             
-            numberOfInterfaces += header->num_interfaces;
+            totalNumberOfInterfaces += header->num_interfaces;
             if (k == 0) {
-                IDE_array = PR_CALLOC(numberOfInterfaces * sizeof(XPTInterfaceDirectoryEntry));
+                IDE_array = PR_CALLOC(totalNumberOfInterfaces * sizeof(XPTInterfaceDirectoryEntry));
+                fix_array = PR_CALLOC(totalNumberOfInterfaces * sizeof(fixElement));
             } else {
-                newIDE = PR_REALLOC(IDE_array, numberOfInterfaces * sizeof(XPTInterfaceDirectoryEntry));
+                newIDE = PR_REALLOC(IDE_array, totalNumberOfInterfaces * sizeof(XPTInterfaceDirectoryEntry));
+                newFix = PR_REALLOC(fix_array, totalNumberOfInterfaces * sizeof(fixElement));
+
                 if (!newIDE) {
                     perror("FAILED: PR_REALLOC of IDE_array");
                     return 1;
                 }
+                if (!newFix) {
+                    perror("FAILED: PR_REALLOC of newFix");
+                    return 1;
+                }
                 IDE_array = newIDE;
+                fix_array = newFix;
             }
             
             for (j=0; j<header->num_interfaces; j++) {
@@ -125,6 +154,12 @@ main(int argc, char **argv)
                     perror("FAILED: 1st copying of IDE");
                     return 1;
                 }
+                fix_array[k].iid = &IDE_array[k].iid;
+                fix_array[k].name = IDE_array[k].name;
+                fix_array[k].file_num = i-2;
+                fix_array[k].interface_num = j+1;
+                fix_array[k].is_deleted = PR_FALSE;
+
                 k++;
             }
             
@@ -140,16 +175,180 @@ main(int argc, char **argv)
             return 1;
         }
     }
- 
+
+    /* Sort both IDE_array and fix_array by name so we can check for 
+     * name_space::name collisions. 
+     */
     qsort(IDE_array, 
-          numberOfInterfaces, 
+          totalNumberOfInterfaces, 
+          sizeof(XPTInterfaceDirectoryEntry), 
+          compare_IDEs_by_name);
+
+    qsort(fix_array, 
+          totalNumberOfInterfaces, 
+          sizeof(fixElement), 
+          compare_fixElements_by_name);
+
+    /* Iterate through fix_array now that it is in its final form (sorted)
+     * and set the index. Index is i+1 because index 0 is reserved for
+     * the special case (no parent interface).
+     */
+    for (i=0; i<totalNumberOfInterfaces; i++) {
+        fix_array[k].index = i+1;
+    }
+
+    /* trueNumberOfInterfaces == number of interfaces left after deletions
+     * are made. Initialize it here to be the same as the total number of
+     * interfaces we'ce encountered thus far.
+     */
+    trueNumberOfInterfaces = totalNumberOfInterfaces;
+
+    /* Iterate through the sorted interfaces. Start at one so we don't 
+     * accidentally walk off the end of the array.
+     */
+    i = 1;
+    while (i != trueNumberOfInterfaces) {
+        
+        /* Check for name_space::name collision. 
+         */
+        if (compare_IDEs_by_name(&IDE_array[i-1], &IDE_array[i]) == 0 && 
+            compare_IDEs_by_name_space(&IDE_array[i-1], &IDE_array[i]) == 0) {
+            
+            /* If one of the interfaces is unresolved, delete that one 
+             * preferentailly.
+             */
+            if (!&IDE_array[i-1].iid) {
+                /* Shrink the IDE_array to delete the duplicate interface.
+                 */
+                if (!shrink_IDE_array(IDE_array, 
+                                      i-1, 
+                                      trueNumberOfInterfaces)) {
+                    perror("FAILED: shrink_IDE_array");
+                    return 1;
+                }
+                /* Update the fix_array so that the index that corresponds
+                 * to the just-deleted IDE now points to the surviving IDE
+                 * of the same name. Indices are one-based, so the second 
+                 * argument is passed as i+1 (instead of i).
+                 */
+                update_fix_array(&fix_array[i-1], i+1);
+                /* Decrement the true number of interfaces since we just
+                 * deleted one. There's more than one way to get out of
+                 * this loop.
+                 */
+                trueNumberOfInterfaces--;
+            } else {
+                if (!&IDE_array[i].iid || 
+                    (compare_IIDs(&IDE_array[i-1].iid, &IDE_array[i].iid) == 0)) {
+                    /* Shrink the IDE_array to delete the duplicate interface.
+                     */
+                    if (!shrink_IDE_array(IDE_array, 
+                                          i, 
+                                          trueNumberOfInterfaces)) {
+                        perror("FAILED: shrink_IDE_array");
+                        return 1;
+                    }
+                    /* Update the fix_array so that the index that corresponds
+                     * to the just-deleted IDE now points to the surviving IDE
+                     * of the same name. Indices are one-based, so the second 
+                     * argument is passed as i (instead of i-1).
+                     */
+                    update_fix_array(&fix_array[i], i);
+                    /* Decrement the true number of interfaces since we just
+                     * deleted one. There's more than one way to get out of
+                     * this loop.
+                     */
+                    trueNumberOfInterfaces--;
+                }
+            }
+            
+        } else {
+            /* Only increment if there was no name_space::name collision.
+             */
+            i++;
+        }
+    }
+
+    /* Iterate through the remaining interfaces. There's some magic here - 
+     * we walk fix_array at the same time skipping over ones that have 
+     * been deleted. This should work correctly since we only ever delete
+     * things in a linear manner.
+     */
+    for (i=0,j=0; 
+         i<trueNumberOfInterfaces && j<totalNumberOfInterfaces; 
+         i++,j++) {
+        
+        /* Define id to save some keystrokes.
+         */
+        id = IDE_array[i].interface_descriptor;
+        /* Skip ahead in fix_array until past the deleted elements.
+         */
+        while (fix_array[j].is_deleted) {
+            j++;
+        }
+        /* Fix parent_interface first.
+         */
+        if (id->parent_interface != 0) {
+            id->parent_interface = 
+                get_new_index(fix_array, totalNumberOfInterfaces,
+                              fix_array[j].file_num, id->parent_interface);
+        }
+        /* Iterate through the method descriptors looking for params of
+         * type TD_INTERFACE_TYPE.
+         */
+        for (k=0; k<id->num_methods; k++) {
+            /* Cycle through the params first.
+             */
+            for (l=0; l<id->method_descriptors[k].num_args; l++) {
+                /* Define td to save some keystrokes.
+                 */
+                td = &id->method_descriptors[k].params[l].type;
+                if (XPT_TDP_TAG(td->prefix) == TD_INTERFACE_TYPE) {
+                    td->type.interface = 
+                        get_new_index(fix_array, 
+                                      totalNumberOfInterfaces,
+                                      fix_array[j].file_num, 
+                                      td->type.interface);
+                }                                                
+            }
+
+            /* Check the result param too. Define td again to save 
+             * some keystrokes.
+             */
+            td = &id->method_descriptors[k].result->type;
+            if (XPT_TDP_TAG(td->prefix) == TD_INTERFACE_TYPE) {
+                td->type.interface = 
+                    get_new_index(fix_array, totalNumberOfInterfaces,
+                                  fix_array[j].file_num, td->type.interface);
+            }                
+        }
+    } 
+
+    /* Sort the IDE_array by IID for output to xpt file.
+     */
+    qsort(IDE_array, 
+          trueNumberOfInterfaces, 
           sizeof(XPTInterfaceDirectoryEntry), 
           compare_IDEs_by_IID);
 
-    header = XPT_NewHeader(numberOfInterfaces);
+    /* Iterate through the array quickly looking for duplicate IIDS.
+     * This shouldn't happen, i.e. is a failure condition, so bail
+     * if we find a duplicate. If we have more than one entry, start 
+     * at one so we don't accidentally grep the ether.
+     */
+    if (trueNumberOfInterfaces>1) {
+        for (i=1; i<trueNumberOfInterfaces; i++) {
+            if (compare_IDEs_by_IID(&IDE_array[i-1], &IDE_array[i]) == 0) {
+                perror("Error: Whoa, Nellie! You've got duplicate IIDs.");
+                return 1;
+            }
+        }
+    }
+
+    header = XPT_NewHeader(trueNumberOfInterfaces);
     ann = XPT_NewAnnotation(XPT_ANN_LAST, NULL, NULL);
     header->annotations = ann;
-    for (i=0; i<numberOfInterfaces; i++) {
+    for (i=0; i<trueNumberOfInterfaces; i++) {
         if (!copy_IDE(&IDE_array[i], &header->interface_directory[i])) {
             perror("FAILED: 2nd copying of IDE");
             return 1;
@@ -215,6 +414,24 @@ compare_IDEs_by_name(const void *ap,
     
     return strcmp(ide1->name, ide2->name);
 }
+
+static int 
+compare_IDEs_by_name_space(const void *ap,
+                           const void *bp)
+{
+    const XPTInterfaceDirectoryEntry *ide1 = ap, *ide2 = bp;
+    
+    return strcmp(ide1->name_space, ide2->name_space);
+}
+
+static int 
+compare_fixElements_by_name(const void *ap,
+                    const void *bp)
+{
+    const fixElement *fix1 = ap, *fix2 = bp;
+    
+    return strcmp(fix1->name, fix2->name);
+}
     
 static int
 compare_IIDs(const void *ap, const void *bp)
@@ -233,6 +450,59 @@ compare_IIDs(const void *ap, const void *bp)
 #undef COMPARE
 }
 
+PRBool 
+shrink_IDE_array(XPTInterfaceDirectoryEntry *ide, int element_to_delete,
+                    int num_interfaces)
+{
+    int i;
+
+    if (element_to_delete >= num_interfaces) {
+        return PR_FALSE;
+    }
+
+    for (i=element_to_delete+1; i<num_interfaces; i++) {
+        if (!copy_IDE(&ide[i], &ide[i-1])) {
+            return PR_FALSE;
+        }
+    }
+
+    return PR_TRUE;
+}
+
+/* update_fix_array marks a fixElement as deleted and updates the index 
+ *  marker. Deleted elements are not used for comparison purposes with 
+ * IDE_array. There only purpose is to set the interface index (if 
+ * necessary) for id->parent_interfaces and TypeDescriptors once the IDEs 
+ * are sorted and pruned. 
+ */
+PRBool 
+update_fix_array(fixElement *deleted, int new_index) 
+{
+    deleted->is_deleted = PR_TRUE;
+    deleted->index = new_index;
+    
+    return PR_TRUE;
+}
+
+/* get_new_index returns the new interface index by walking the fix_array
+ * until the file_num and interface_num match the target values. Indices 
+ * are one-based; zero represents the special case (no parent interface). 
+ */
+static int 
+get_new_index(const fixElement *fix, int num_elements, 
+              int target_file, int target_interface) 
+{
+    int i;
+    
+    for (i=0; i<num_elements; i++) { 
+        if (fix[i].file_num == target_file &&
+            fix[i].interface_num == target_interface)
+            return fix[i].index;
+    }
+    
+    return 0;
+}
+
 PRBool
 copy_IDE(XPTInterfaceDirectoryEntry *from, XPTInterfaceDirectoryEntry *to) 
 {