[PATCH] abg-reader: eliminate unreachable-code-loop-increment warnings

[Giuliano Procida <gprocida@google.com>]

This commit tidies up some debris from the change to use
xmlFirstElementChild and xmlNextElementSibling. A couple of while
loops had bodies which would be executed exactly once searching for
the next element with a given tag. These trigger warnings with recent
Clang++, at least.

This commit replaces the loops with their bodies and eliminates
a little redundant conditional logic.

There is no change in behaviour.

	* src/abg-reader.cc (read_translation_unit_from_input): In the
	branch where the context object holds a non-null node, just
	check that it an abi-instr; remove the final null check on
	node as it is guaranteed to be non-null.
	(read_elf_needed_from_input): Save the context object's node
	in node immediately; in the branch where the context object
	holds a non-null node, just check that it an elf-needed;
	remove the final null check on node as it is guaranteed to be
	non-null.

Signed-off-by: Giuliano Procida <gprocida@google.com>
---
 src/abg-reader.cc | 41 +++++++++--------------------------------
 1 file changed, 9 insertions(+), 32 deletions(-)

diff --git a/src/abg-reader.cc b/src/abg-reader.cc
index 0b8149f6..793ca828 100644
--- a/src/abg-reader.cc
+++ b/src/abg-reader.cc
@@ -1576,21 +1576,10 @@ read_translation_unit_from_input(read_context&	ctxt)
     }
   else
     {
-      node = 0;
-      for (xmlNodePtr n = ctxt.get_corpus_node();
-	   n;
-	   n = xmlNextElementSibling(n))
-	{
-	  if (!xmlStrEqual(n->name, BAD_CAST("abi-instr")))
-	    return nil;
-	  node = n;
-	  break;
-	}
+      if (!xmlStrEqual(node->name, BAD_CAST("abi-instr")))
+	return nil;
     }
 
-  if (node == 0)
-    return nil;
-
   tu = get_or_read_and_add_translation_unit(ctxt, node);
 
   if (ctxt.get_corpus_node())
@@ -1740,9 +1729,8 @@ read_elf_needed_from_input(read_context&	ctxt,
   if (!reader)
     return false;
 
-  xmlNodePtr node = 0;
-
-  if (ctxt.get_corpus_node() == 0)
+  xmlNodePtr node = ctxt.get_corpus_node();
+  if (!node)
     {
       int status = 1;
       while (status == 1
@@ -1762,24 +1750,13 @@ read_elf_needed_from_input(read_context&	ctxt,
     }
   else
     {
-      for (xmlNodePtr n = ctxt.get_corpus_node();
-	   n;
-	   n = xmlNextElementSibling(n))
-	{
-	  if (!xmlStrEqual(n->name, BAD_CAST("elf-needed")))
-	    return false;
-	  node = n;
-	  break;
-	}
+      if (!xmlStrEqual(node->name, BAD_CAST("elf-needed")))
+        return false;
     }
 
-  bool result = false;
-  if (node)
-    {
-      result = build_needed(node, needed);
-      node = xmlNextElementSibling(node);
-      ctxt.set_corpus_node(node);
-    }
+  bool result = build_needed(node, needed);
+  node = xmlNextElementSibling(node);
+  ctxt.set_corpus_node(node);
 
   return result;
 }
-- 
2.32.0.272.g935e593368-goog