abg-reader: eliminate unreachable-code-loop-increment warnings
Commit Message
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(-)
Comments
On Wed, Jun 16, 2021 at 02:30:03PM +0100, Giuliano Procida wrote:
>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>
Reviewed-by: Matthias Maennich <maennich@google.com>
Cheers,
Matthias
>---
> 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
>
@@ -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;
}