xml: make the get_content beginp parameter const char **

Since we sometimes return a constant string, the caller shall not modify it

Signed-off-by: Samuel Thibault <samuel.thibault@ens-lyon.org>
(cherry picked from commit 2ad4cb8)

hwloc/topology-xml-libxml.c

@@ -1,7 +1,7 @@
 /*
  * Copyright © 2009 CNRS
  * Copyright © 2009-2018 Inria.  All rights reserved.
- * Copyright © 2009-2011 Université Bordeaux
+ * Copyright © 2009-2011, 2020 Université Bordeaux
  * Copyright © 2009-2011 Cisco Systems, Inc.  All rights reserved.
  * See COPYING in top-level directory.
  */
@@ -145,7 +145,7 @@ hwloc__libxml_import_close_child(hwloc__xml_import_state_t state __hwloc_attribu
 
 static int
 hwloc__libxml_import_get_content(hwloc__xml_import_state_t state,
-				 char **beginp, size_t expected_length)
+				 const char **beginp, size_t expected_length)
 {
   hwloc__libxml_import_state_data_t lstate = (void*) state->data;
   xmlNode *child;
@@ -155,14 +155,14 @@ hwloc__libxml_import_get_content(hwloc__xml_import_state_t state,
   if (!child || child->type != XML_TEXT_NODE) {
     if (expected_length)
       return -1;
-    *beginp = (char *) "";
+    *beginp = "";
     return 0;
   }
 
   length = strlen((char *) child->content);
   if (length != expected_length)
     return -1;
-  *beginp = (char *) child->content;
+  *beginp = (const char*) child->content;
   return 1;
 }
 

hwloc/topology-xml-nolibxml.c

@@ -213,7 +213,7 @@ hwloc__nolibxml_import_close_child(hwloc__xml_import_state_t state)
 
 static int
 hwloc__nolibxml_import_get_content(hwloc__xml_import_state_t state,
-				   char **beginp, size_t expected_length)
+				   const char **beginp, size_t expected_length)
 {
   hwloc__nolibxml_import_state_data_t nstate = (void*) state->data;
   char *buffer = nstate->tagbuffer;
@@ -224,7 +224,7 @@ hwloc__nolibxml_import_get_content(hwloc__xml_import_state_t state,
   if (nstate->closed) {
     if (expected_length)
       return -1;
-    *beginp = (char *) "";
+    *beginp = "";
     return 0;
   }
 

hwloc/topology-xml.c

@@ -1,7 +1,7 @@
 /*
  * Copyright © 2009 CNRS
  * Copyright © 2009-2020 Inria.  All rights reserved.
- * Copyright © 2009-2011 Université Bordeaux
+ * Copyright © 2009-2011, 2020 Université Bordeaux
  * Copyright © 2009-2018 Cisco Systems, Inc.  All rights reserved.
  * See COPYING in top-level directory.
  */
@@ -694,14 +694,15 @@ hwloc__xml_import_userdata(hwloc_topology_t topology __hwloc_attribute_unused, h
   }
 
   if (!topology->userdata_import_cb) {
-    char *buffer;
+    const char *buffer;
     size_t reallength = encoded ? BASE64_ENCODED_LENGTH(length) : length;
     ret = state->global->get_content(state, &buffer, reallength);
     if (ret < 0)
       return -1;
 
   } else if (topology->userdata_not_decoded) {
-      char *buffer, *fakename;
+      const char *buffer;
+      char *fakename;
       size_t reallength = encoded ? BASE64_ENCODED_LENGTH(length) : length;
       ret = state->global->get_content(state, &buffer, reallength);
       if (ret < 0)
@@ -714,7 +715,7 @@ hwloc__xml_import_userdata(hwloc_topology_t topology __hwloc_attribute_unused, h
       free(fakename);
 
   } else if (encoded && length) {
-      char *encoded_buffer;
+      const char *encoded_buffer;
       size_t encoded_length = BASE64_ENCODED_LENGTH(length);
       ret = state->global->get_content(state, &encoded_buffer, encoded_length);
       if (ret < 0)
@@ -734,7 +735,7 @@ hwloc__xml_import_userdata(hwloc_topology_t topology __hwloc_attribute_unused, h
       }
 
   } else { /* always handle length==0 in the non-encoded case */
-      char *buffer = (char *) "";
+      const char *buffer = "";
       if (length) {
 	ret = state->global->get_content(state, &buffer, length);
 	if (ret < 0)
@@ -1317,7 +1318,8 @@ hwloc__xml_v2import_distances(hwloc_topology_t topology,
   nr_u64values = 0;
   while (1) {
     struct hwloc__xml_import_state_s childstate;
-    char *attrname, *attrvalue, *tag, *buffer;
+    char *attrname, *attrvalue, *tag;
+    const char *buffer;
     int length;
     int is_index = 0;
     int is_u64values = 0;
@@ -1356,7 +1358,7 @@ hwloc__xml_v2import_distances(hwloc_topology_t topology,
 
     if (is_index) {
       /* get indexes */
-      char *tmp, *tmp2;
+      const char *tmp, *tmp2;
       if (nr_indexes >= nbobjs) {
 	if (hwloc__xml_verbose())
 	  fprintf(stderr, "%s: %s with more than %u indexes\n",
@@ -1398,7 +1400,7 @@ hwloc__xml_v2import_distances(hwloc_topology_t topology,
 
     } else if (is_u64values) {
       /* get uint64_t values */
-      char *tmp;
+      const char *tmp;
       if (nr_u64values >= nbobjs*nbobjs) {
 	if (hwloc__xml_verbose())
 	  fprintf(stderr, "%s: %s with more than %u u64values\n",

include/private/xml.h

@@ -46,7 +46,7 @@ struct hwloc_xml_backend_data_s {
   int (*find_child)(struct hwloc__xml_import_state_s * state, struct hwloc__xml_import_state_s * childstate, char **tagp);
   int (*close_tag)(struct hwloc__xml_import_state_s * state); /* look for an explicit closing tag </name> */
   void (*close_child)(struct hwloc__xml_import_state_s * state);
-  int (*get_content)(struct hwloc__xml_import_state_s * state, char **beginp, size_t expected_length); /* return 0 on empty content (and sets beginp to empty string), 1 on actual content, -1 on error or unexpected content length */
+  int (*get_content)(struct hwloc__xml_import_state_s * state, const char **beginp, size_t expected_length); /* return 0 on empty content (and sets beginp to empty string), 1 on actual content, -1 on error or unexpected content length */
   void (*close_content)(struct hwloc__xml_import_state_s * state);
   char * msgprefix;
   void *data; /* libxml2 doc, or nolibxml buffer */