From: David Malcolm <dmalcolm@redhat.com>
To: Jason Merrill <jason@redhat.com>, Martin Sebor <msebor@gmail.com>
Cc: Nathan Sidwell <nathan@acm.org>, Jakub Jelinek <jakub@redhat.com>,
Richard Biener <richard.guenther@gmail.com>,
gcc-patches List <gcc-patches@gcc.gnu.org>,
David Malcolm <dmalcolm@redhat.com>
Subject: [v3 of 05/14] C++: handle locations wrappers when calling warn_for_memset
Date: Wed, 20 Dec 2017 19:23:00 -0000 [thread overview]
Message-ID: <1513797978-14728-1-git-send-email-dmalcolm@redhat.com> (raw)
In-Reply-To: <de9c6d6f-3bb0-2f2c-f920-056fb54b6a72@redhat.com>
On Tue, 2017-12-19 at 15:02 -0500, Jason Merrill wrote:
> On 12/16/2017 03:01 PM, Martin Sebor wrote:
> > On 12/16/2017 06:12 AM, David Malcolm wrote:
> > > On Mon, 2017-12-11 at 18:36 -0500, Jason Merrill wrote:
> > > > On 11/10/2017 04:45 PM, David Malcolm wrote:
> > > > > We need to strip away location wrappers in tree.c predicates
> > > > > like
> > > > > integer_zerop, otherwise they fail when they're called on
> > > > > wrapped INTEGER_CST; an example can be seen for
> > > > > c-c++-common/Wmemset-transposed-args1.c
> > > > > in g++.sum, where the warn_for_memset fails to detect integer
> > > > > zero
> > > > > if the location wrappers aren't stripped.
> > > >
> > > > These shouldn't be needed; callers should have folded away
> > > > location
> > > > wrappers. I would hope for STRIP_ANY_LOCATION_WRAPPER to be
> > > > almost
> > > > never needed.
> > > >
> > > > warn_for_memset may be missing some calls to fold_for_warn.
> > >
> > > It is, thanks.
> > >
> > > Here's a revised fix for e.g. Wmemset-transposed-args1.c,
> > > replacing
> > > "[PATCH 05/14] tree.c: strip location wrappers from integer_zerop
> > > etc"
> > > and
> > > "[PATCH 10/14] warn_for_memset: handle location wrappers"
> > >
> > > This version of the patch simply calls fold_for_warn on each of
> > > the
> > > arguments before calling warn_for_memset. This ensures that
> > > warn_for_memset detects integer zero. It also adds a
> > > literal_integer_zerop to deal with location wrapper nodes when
> > > building "literal_mask" for the call, since this must be called
> > > *before* the fold_for_warn calls.
> > >
> > > Successfully bootstrapped®rtested on x86_64-pc-linux-gnu, as
> > > part of the kit.
> > >
> > > Is this OK for trunk, once the rest of the kit is approved?
> > >
> > > gcc/cp/ChangeLog:
> > > * parser.c (literal_integer_zerop): New function.
> > > (cp_parser_postfix_expression): When calling warn_for_memset,
> > > replace integer_zerop calls with literal_integer_zerop, and
> > > call fold_for_warn on the arguments.
> > > ---
> > > gcc/cp/parser.c | 18 ++++++++++++++++--
> > > 1 file changed, 16 insertions(+), 2 deletions(-)
> > >
> > > diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
> > > index d15769a..7bca460 100644
> > > --- a/gcc/cp/parser.c
> > > +++ b/gcc/cp/parser.c
> > > @@ -6621,6 +6621,16 @@ cp_parser_compound_literal_p (cp_parser
> > > *parser)
> > > return compound_literal_p;
> > > }
> > >
> > > +/* Return 1 if EXPR is the integer constant zero or a complex
> > > constant
> > > + of zero, without any folding, but ignoring location
> > > wrappers. */
> > > +
> > > +static int
> > > +literal_integer_zerop (const_tree expr)
> > > +{
> > > + STRIP_ANY_LOCATION_WRAPPER (expr);
> > > + return integer_zerop (expr);
> > > +}
> > > +
> > > /* Parse a postfix-expression.
> > >
> > > postfix-expression:
> > > @@ -7168,8 +7178,12 @@ cp_parser_postfix_expression (cp_parser
> > > *parser, bool address_p, bool cast_p,
> > > tree arg0 = (*args)[0];
> > > tree arg1 = (*args)[1];
> > > tree arg2 = (*args)[2];
> > > - int literal_mask = ((!!integer_zerop (arg1) << 1)
> > > - | (!!integer_zerop (arg2) << 2));
> > > + /* Handle any location wrapper nodes. */
> > > + arg0 = fold_for_warn (arg0);
> > > + int literal_mask = ((!!literal_integer_zerop (arg1) <<
> > > 1)
> > > + | (!!literal_integer_zerop (arg2) << 2));
> >
> > The double negation jumped out at me. The integer_zerop() function
> > looks like a predicate that hasn't yet been converted to return
> > bool.
> > It seems that new predicates that are implemented on top of it
> > could
> > return bool and their callers avoid this conversion. (At some
> > point
> > in the future it would also be nice to convert the existing
> > predicates to return bool).
>
> Agreed. And since integer_zerop in fact returns boolean values,
> there
> seems to be no need for the double negative in the first place.
>
> So, please make the new function return bool and remove the !!s.
>
> And I think the fold_for_warn call should be in warn_for_memset, and
> it
> should be called for arg2 as well instead of specifically handling
> CONST_DECL Here.
Thanks.
Here's an updated version of the patch which I believe covers all
of the above.
Successfully bootstrapped®rtested on x86_64-pc-linux-gnu, as
part of the kit.
OK for trunk once the rest of the kit is approved?
gcc/c-family/ChangeLog:
* c-warn.c (warn_for_memset): Call fold_for_warn on the arguments.
gcc/cp/ChangeLog:
* parser.c (literal_integer_zerop): New function.
(cp_parser_postfix_expression): When calling warn_for_memset,
replace integer_zerop calls with literal_integer_zerop,
eliminating the double logical negation cast to bool.
Eliminate the special-casing for CONST_DECL in favor of the
fold_for_warn within warn_for_memset.
---
gcc/c-family/c-warn.c | 3 +++
gcc/cp/parser.c | 16 ++++++++++++----
2 files changed, 15 insertions(+), 4 deletions(-)
diff --git a/gcc/c-family/c-warn.c b/gcc/c-family/c-warn.c
index 6045d6e..baaf37e 100644
--- a/gcc/c-family/c-warn.c
+++ b/gcc/c-family/c-warn.c
@@ -1865,6 +1865,9 @@ void
warn_for_memset (location_t loc, tree arg0, tree arg2,
int literal_zero_mask)
{
+ arg0 = fold_for_warn (arg0);
+ arg2 = fold_for_warn (arg2);
+
if (warn_memset_transposed_args
&& integer_zerop (arg2)
&& (literal_zero_mask & (1 << 2)) != 0
diff --git a/gcc/cp/parser.c b/gcc/cp/parser.c
index d15769a..adfca60 100644
--- a/gcc/cp/parser.c
+++ b/gcc/cp/parser.c
@@ -6621,6 +6621,16 @@ cp_parser_compound_literal_p (cp_parser *parser)
return compound_literal_p;
}
+/* Return true if EXPR is the integer constant zero or a complex constant
+ of zero, without any folding, but ignoring location wrappers. */
+
+static bool
+literal_integer_zerop (const_tree expr)
+{
+ STRIP_ANY_LOCATION_WRAPPER (expr);
+ return integer_zerop (expr);
+}
+
/* Parse a postfix-expression.
postfix-expression:
@@ -7168,10 +7178,8 @@ cp_parser_postfix_expression (cp_parser *parser, bool address_p, bool cast_p,
tree arg0 = (*args)[0];
tree arg1 = (*args)[1];
tree arg2 = (*args)[2];
- int literal_mask = ((!!integer_zerop (arg1) << 1)
- | (!!integer_zerop (arg2) << 2));
- if (TREE_CODE (arg2) == CONST_DECL)
- arg2 = DECL_INITIAL (arg2);
+ int literal_mask = ((literal_integer_zerop (arg1) << 1)
+ | (literal_integer_zerop (arg2) << 2));
warn_for_memset (input_location, arg0, arg2, literal_mask);
}
--
1.8.5.3
next prev parent reply other threads:[~2017-12-20 19:23 UTC|newest]
Thread overview: 111+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-10-20 22:38 [PATCH] RFC: Preserving locations for variable-uses and constants (PR 43486) David Malcolm
2017-10-24 14:05 ` Jason Merrill
2017-10-31 21:28 ` David Malcolm
2017-11-02 14:46 ` Jason Merrill
2017-11-10 21:43 ` [PATCH v2: 00/14] " David Malcolm
2017-11-10 21:43 ` [PATCH 06/14] Fix Wsizeof-pointer-memaccess*.c David Malcolm
2017-12-11 23:37 ` Jason Merrill
2017-12-18 2:04 ` [v2 of PATCH 06/14] Strip location wrappers in operand_equal_p David Malcolm
2017-12-18 8:00 ` Jakub Jelinek
2017-12-19 20:13 ` Jason Merrill
2017-12-19 20:49 ` Jakub Jelinek
2017-12-19 21:59 ` Jason Merrill
2017-12-19 22:03 ` Jakub Jelinek
2017-12-20 0:41 ` [PATCH] Eliminate location wrappers in tree_nop_conversion/STRIP_NOPS David Malcolm
2017-12-20 4:27 ` Jeff Law
2017-11-10 21:43 ` [PATCH 02/14] Support for adding and stripping location_t wrapper nodes David Malcolm
2017-11-15 6:31 ` Trevor Saunders
2017-11-15 11:23 ` Richard Biener
2017-11-15 15:40 ` David Malcolm
2017-11-16 10:04 ` Richard Biener
2017-11-30 17:25 ` [PATCH v2.1] " David Malcolm
2017-11-30 17:46 ` Jason Merrill
2017-11-30 18:38 ` [PATCH, v2.2] " David Malcolm
2017-11-30 20:30 ` Jason Merrill
2017-11-10 21:43 ` [PATCH 07/14] reject_gcc_builtin: strip any location wrappers David Malcolm
2017-12-11 23:38 ` Jason Merrill
2017-11-10 21:43 ` [PATCH 01/14] C++: preserve locations within build_address David Malcolm
2017-12-11 23:25 ` Jason Merrill
2017-11-10 21:43 ` [PATCH 03/14] C++: add location_t wrapper nodes during parsing (minimal impl) David Malcolm
2017-12-12 2:10 ` Jason Merrill
2017-12-14 19:25 ` David Malcolm
2017-12-15 15:02 ` Jason Merrill
2017-12-15 16:35 ` David Malcolm
2017-12-15 18:59 ` Jason Merrill
2017-12-15 22:49 ` David Malcolm
2017-12-29 17:03 ` [v2 of PATCH " David Malcolm
2018-01-05 20:29 ` Jason Merrill
2018-01-05 22:20 ` David Malcolm
2018-01-08 17:10 ` Location wrappers vs decls that change type (was Re: [v2 of PATCH 03/14] C++: add location_t wrapper nodes during parsing (minimal impl)) David Malcolm
2018-01-08 17:14 ` Nathan Sidwell
2018-01-08 17:18 ` Jakub Jelinek
2018-01-08 17:28 ` Nathan Sidwell
2018-01-08 18:08 ` David Malcolm
2018-01-08 18:23 ` Jakub Jelinek
2018-01-09 11:34 ` [PATCH v2.4 of 02/14] Support for adding and stripping location_t wrapper nodes David Malcolm
2018-01-09 14:59 ` Jason Merrill
2018-01-08 21:48 ` [v2 of PATCH 03/14] C++: add location_t wrapper nodes during parsing (minimal impl) Jason Merrill
2018-01-08 21:03 ` David Malcolm
2018-01-08 21:59 ` Jason Merrill
2018-01-08 22:27 ` Jason Merrill
2018-01-09 12:03 ` [PATCH v3 of " David Malcolm
2018-01-09 14:39 ` Jason Merrill
2018-01-09 14:39 ` Jakub Jelinek
2018-01-09 18:32 ` [PATCH v4 " David Malcolm
2018-01-09 19:45 ` Jason Merrill
2017-11-10 21:43 ` [PATCH 05/14] tree.c: strip location wrappers from integer_zerop etc David Malcolm
2017-12-11 23:36 ` Jason Merrill
2017-12-16 13:09 ` [PATCH] C++: handle locations wrappers when calling warn_for_memset David Malcolm
2017-12-16 20:01 ` Martin Sebor
2017-12-19 20:02 ` Jason Merrill
2017-12-20 19:23 ` David Malcolm [this message]
2017-12-21 4:58 ` [v3 of 05/14] " Jason Merrill
2017-11-10 21:44 ` [PATCH 13/14] c-format.c: handle location wrappers David Malcolm
2017-12-11 23:45 ` Jason Merrill
2017-12-17 16:26 ` [v2 of PATCH " David Malcolm
2017-12-19 19:55 ` Jason Merrill
2017-12-20 17:33 ` David Malcolm
2017-12-21 5:03 ` Jason Merrill
2017-12-22 19:07 ` [v3 " David Malcolm
2018-01-05 17:35 ` PING " David Malcolm
2018-01-05 17:48 ` Joseph Myers
2018-01-05 20:21 ` Jason Merrill
2017-11-10 21:44 ` [PATCH 09/14] Strip location wrappers in null_ptr_cst_p David Malcolm
2017-12-11 23:39 ` Jason Merrill
2017-11-10 21:44 ` [PATCH 08/14] cp/tree.c: strip location wrappers in lvalue_kind David Malcolm
2017-12-11 23:39 ` Jason Merrill
2017-12-20 22:11 ` [v2 of PATCH " David Malcolm
2017-12-21 4:56 ` Jason Merrill
2017-12-21 17:47 ` [v3 " David Malcolm
2017-12-21 22:44 ` Jason Merrill
2017-11-10 21:44 ` [PATCH 10/14] warn_for_memset: handle location wrappers David Malcolm
2017-12-11 23:41 ` Jason Merrill
2017-11-10 21:44 ` [PATCH 04/14] Update testsuite to show improvements David Malcolm
2017-11-10 21:44 ` [PATCH 11/14] Handle location wrappers in string_conv_p David Malcolm
2017-12-11 23:42 ` Jason Merrill
2017-11-10 21:44 ` [PATCH 14/14] pp_c_cast_expression: don't print casts for location wrappers David Malcolm
2017-12-11 23:46 ` Jason Merrill
2017-11-10 22:11 ` [PATCH 12/14] C++: introduce null_node_p David Malcolm
2017-12-11 23:42 ` Jason Merrill
2017-11-13 19:20 ` [PATCH v2: 00/14] Preserving locations for variable-uses and constants (PR 43486) David Malcolm
2017-11-18 2:50 ` [RFC v3 00/11] C++: locations for (almost) everything " David Malcolm
2017-11-18 2:50 ` [PATCH 03/11] Implement STRIP_ANY_LOCATION_WRAPPER_SAFE David Malcolm
2017-11-18 2:50 ` [PATCH 02/11] cp_tree::maybe_add_location_wrapper: no-op for template decls David Malcolm
2017-11-18 2:50 ` [PATCH 01/11] C++: Add location wrappers for all constants and decls David Malcolm
2017-11-18 2:50 ` [PATCH 06/11] gcc: Handle location wrappers in operand_equal_p David Malcolm
2017-11-18 2:51 ` [PATCH 07/11] c-family: handle location wrappers David Malcolm
2017-11-18 2:51 ` [PATCH 04/11] C++: add cp_expr::strip_any_location_wrapper method David Malcolm
2017-11-18 2:51 ` [PATCH 09/11] objc: handle location wrappers in objc_maybe_build_component_ref David Malcolm
2017-11-18 2:51 ` [PATCH 08/11] C++: handle location wrappers David Malcolm
2017-11-18 2:51 ` [PATCH 05/11] C++: finish_call_expr: strip location wrapper David Malcolm
2017-11-18 3:23 ` [PATCH 11/11] config: handle location wrappers in various attributes (untested) David Malcolm
2017-11-18 3:54 ` [PATCH 10/11] i386: handle location wrappers in ix86_handle_cconv_attribute David Malcolm
2017-11-30 20:54 ` [PATCH v2: 00/14] Preserving locations for variable-uses and constants (PR 43486) David Malcolm
2017-12-11 16:08 ` [PING ^ 2] " David Malcolm
2017-12-17 1:10 ` [PATCH 15/14] Use fold_for_warn in get_atomic_generic_size David Malcolm
2017-12-19 20:35 ` Jason Merrill
2017-12-20 0:50 ` [v2 of PATCH " David Malcolm
2017-12-20 4:22 ` Jason Merrill
2017-12-20 19:33 ` [v3 " David Malcolm
2017-12-21 4:57 ` Jason Merrill
2018-01-10 19:51 ` [committed] Preserving locations for variable-uses and constants (PR c++/43486) David Malcolm
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