From: Ian Lance Taylor <iant@google.com>
To: "Iyer\, Balaji V" <balaji.v.iyer@intel.com>
Cc: "'gcc\@gcc.gnu.org'" <gcc@gcc.gnu.org>
Subject: Re: Question about default_elf_asm_named_section function
Date: Fri, 14 Oct 2011 06:59:00 -0000 [thread overview]
Message-ID: <mcrwrc86vdm.fsf@coign.corp.google.com> (raw)
In-Reply-To: <2950715866004049A240A2F9BB410E7315F42971CC@azsmsx502.amr.corp.intel.com> (Balaji V. Iyer's message of "Wed, 12 Oct 2011 15:14:35 -0700")
"Iyer, Balaji V" <balaji.v.iyer@intel.com> writes:
> This email is in reference to the "default_elf_asm_named_section" function in the varasm.c file.
>
> This function is defined like this:
>
> void
> default_elf_asm_named_section (const char *name, unsigned int flags,
> tree decl ATTRIBUTE_UNUSED)
>
>
> But, inside the function, there is this if-statement:
>
>
> if (HAVE_COMDAT_GROUP && (flags & SECTION_LINKONCE))
> {
> if (TREE_CODE (decl) == IDENTIFIER_NODE)
> fprintf (asm_out_file, ",%s,comdat", IDENTIFIER_POINTER (decl));
> else
> fprintf (asm_out_file, ",%s,comdat",
> IDENTIFIER_POINTER (DECL_COMDAT_GROUP (decl)));
> }
>
>
> The decl is set with "ATTRIBUTE_UNUSED" but the if-statement is using "decl." Should we remove the attribute unused tag near the "tree decl" or is the if-statement a deadcode that should never be ?
ATTRIBUTE_UNUSED does not mean "this parameter is never used." It means
"this parameter may not be used." The difference is due to #ifdefs--if
a parameter is only used in code that is something #ifdef'ed out, then
the parameter should be marked as ATTRIBUTE_UNUSED.
In this case the parameter is always used, so we might as well remove
the ATTRIBUTE_UNUSED.
Ian
next prev parent reply other threads:[~2011-10-14 4:38 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-10-13 11:41 Iyer, Balaji V
2011-10-14 6:59 ` Ian Lance Taylor [this message]
2011-10-14 17:34 ` Iyer, Balaji V
2011-10-15 6:08 ` Ian Lance Taylor
2011-10-15 8:58 ` Iyer, Balaji V
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