On 10/1/18 3:46 PM, Christophe Lyon wrote:
> On Sat, 29 Sep 2018 at 18:06, Jeff Law <l...@redhat.com> wrote:
>>
>>
>> This patch changes the NONSTR argument to c_strlen to instead be a
>> little data structure c_strlen can populate with nuggets of information
>> about the string.
>>
>> There's clearly a need for the decl related to the non-string argument.
>> I see an immediate need for the length of a non-terminated string
>> (c_strlen returns NULL for non-terminated strings). I also see a need
>> for the offset within the non-terminated strong as well.
>>
>> We only populate the structure when c_strlen encounters a non-terminated
>> string. One could argue we should always fill in the members. Right
>> now I think filling it in for unterminated cases makes the most sense,
>> but I could be convinced otherwise.
>>
>> I won't be surprised if subsequent warnings from Martin need additional
>> information about the string. The idea here is we can add more elements
>> to the structure without continually adding arguments to c_strlen.
>>
>> Bootstrapped in isolation as well as with Martin's patches for strnlen
>> and sprintf checking. Installing on the trunk.
>>
>
> Hi Jeff,
>
> + /* If TYPE is asking for a maximum, then use any
> + length (including the length of an unterminated
> + string) for VAL. */
> + if (type == 2)
> + val = data.len;
>
> It seems this part is dead-code, since the case type==2 is handled in
> the "then" part of the "if" (this code is in the "else" part).
>
> Since you added a comment, I suspect you explicitly tested it, though?
So it's not needed by patch #6 (strnlen), but patch #4 (not yet
committed) does need some work in this area -- but even so I'm not sure
what that's going to look like yet.
So I've pulled the dead code out and pushed that commit to the trunk
after the usual bootstrap and regression test cycle.
Jeff
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 40f87aaeae5..59a01f86436 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,7 @@
+2018-10-02 Jeff Law <l...@redhat.com>
+
+ * gimple-fold.c (get_range_strlen): Remove dead code.
+
2018-10-02 Martin Sebor <mse...@redhat.com>
Jeff Law <l...@redhat.com>
diff --git a/gcc/gimple-fold.c b/gcc/gimple-fold.c
index cf04c92180b..fa1fc60876c 100644
--- a/gcc/gimple-fold.c
+++ b/gcc/gimple-fold.c
@@ -1345,14 +1345,7 @@ get_range_strlen (tree arg, tree length[2], bitmap
*visited, int type,
/* If we potentially had a non-terminated string, then
bubble that information up to the caller. */
if (!val)
- {
- *nonstr = data.decl;
- /* If TYPE is asking for a maximum, then use any
- length (including the length of an unterminated
- string) for VAL. */
- if (type == 2)
- val = data.len;
- }
+ *nonstr = data.decl;
}
if (!val && fuzzy)
