* [Bug c/97125] new problem with -Wduplicated-branches
2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
@ 2020-09-20 10:37 ` dcb314 at hotmail dot com
2020-09-20 19:06 ` [Bug c/97125] [11 Regression] " mpolacek at gcc dot gnu.org
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From: dcb314 at hotmail dot com @ 2020-09-20 10:37 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
--- Comment #1 from David Binderman <dcb314 at hotmail dot com> ---
Reduced code is
void a() {
if (0)
a;
else
switch (0)
;
}
^ permalink raw reply [flat|nested] 12+ messages in thread* [Bug c/97125] [11 Regression] new problem with -Wduplicated-branches
2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
2020-09-20 10:37 ` [Bug c/97125] " dcb314 at hotmail dot com
@ 2020-09-20 19:06 ` mpolacek at gcc dot gnu.org
2020-09-20 19:06 ` mpolacek at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2020-09-20 19:06 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |mpolacek at gcc dot gnu.org
Target Milestone|--- |11.0
Keywords| |ice-on-valid-code
Summary|new problem with |[11 Regression] new problem
|-Wduplicated-branches |with -Wduplicated-branches
--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Started with r11-3302.
$ ./cc1 -quiet 97125.C -Wduplicated-branches
97125.C: In function ‘a’:
97125.C:11:1: internal compiler error: in hash_operand, at fold-const.c:3768
11 | }
| ^
0xd67ede operand_compare::hash_operand(tree_node const*, inchash::hash&,
unsigned int)
/home/mpolacek/src/gcc/gcc/fold-const.c:3768
0xd6853c operand_compare::hash_operand(tree_node const*, inchash::hash&,
unsigned int)
/home/mpolacek/src/gcc/gcc/fold-const.c:3858
0xd686fa inchash::add_expr(tree_node const*, inchash::hash&, unsigned int)
/home/mpolacek/src/gcc/gcc/fold-const.c:3919
0xac5f4c do_warn_duplicated_branches
/home/mpolacek/src/gcc/gcc/c-family/c-warn.c:2768
0xac6068 do_warn_duplicated_branches_r(tree_node**, int*, void*)
/home/mpolacek/src/gcc/gcc/c-family/c-warn.c:2790
0x1725206 walk_tree_1(tree_node**, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*,
tree_node* (*)(tree_node**, int*, tree_node* (*)(tree_node**, int*, void*),
void*, hash_set<tree_node*, false, default_hash_traits<tree_node*> >*))
/home/mpolacek/src/gcc/gcc/tree.c:12001
0x17269ee walk_tree_without_duplicates_1(tree_node**, tree_node*
(*)(tree_node**, int*, void*), void*, tree_node* (*)(tree_node**, int*,
tree_node* (*)(tree_node**, int*, void*), void*, hash_set<tree_node*, false,
default_hash_traits<tree_node*> >*))
/home/mpolacek/src/gcc/gcc/tree.c:12362
0xa67f30 c_genericize(tree_node*)
/home/mpolacek/src/gcc/gcc/c-family/c-gimplify.c:537
0x951b29 finish_function(unsigned int)
/home/mpolacek/src/gcc/gcc/c/c-decl.c:10219
0x9b66b7 c_parser_declaration_or_fndef
/home/mpolacek/src/gcc/gcc/c/c-parser.c:2562
0x9b4a36 c_parser_external_declaration
/home/mpolacek/src/gcc/gcc/c/c-parser.c:1777
0x9b4598 c_parser_translation_unit
/home/mpolacek/src/gcc/gcc/c/c-parser.c:1650
0x9f28ef c_parse_file()
/home/mpolacek/src/gcc/gcc/c/c-parser.c:21821
0xa8237d c_common_parse_file()
/home/mpolacek/src/gcc/gcc/c-family/c-opts.c:1188
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2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
2020-09-20 10:37 ` [Bug c/97125] " dcb314 at hotmail dot com
2020-09-20 19:06 ` [Bug c/97125] [11 Regression] " mpolacek at gcc dot gnu.org
@ 2020-09-20 19:06 ` mpolacek at gcc dot gnu.org
2020-09-20 19:58 ` mpolacek at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2020-09-20 19:06 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
Last reconfirmed| |2020-09-20
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2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
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2020-09-20 19:06 ` mpolacek at gcc dot gnu.org
@ 2020-09-20 19:58 ` mpolacek at gcc dot gnu.org
2020-09-20 20:07 ` mpolacek at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2020-09-20 19:58 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
We crash because now the C FE uses a SWITCH_STMT in the else branch:
2766 /* Compute the hash of the else branch. */
2767 inchash::hash hstate1 (0);
2768 inchash::add_expr (elseb, hstate1);
2769 hashval_t h1 = hstate1.end ();
but the fold-const.c routines don't know how to handle such a code. This is
not a problem in the C++ FE because by the time we get to
do_warn_duplicated_branches we've already cp_genericize'd the SWITCH_STMT tree
into a SWITCH_EXPR.
^ permalink raw reply [flat|nested] 12+ messages in thread* [Bug c/97125] [11 Regression] new problem with -Wduplicated-branches
2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
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2020-09-20 19:58 ` mpolacek at gcc dot gnu.org
@ 2020-09-20 20:07 ` mpolacek at gcc dot gnu.org
2020-09-20 20:29 ` sandra at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2020-09-20 20:07 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Assignee|unassigned at gcc dot gnu.org |mpolacek at gcc dot gnu.org
Status|NEW |ASSIGNED
^ permalink raw reply [flat|nested] 12+ messages in thread* [Bug c/97125] [11 Regression] new problem with -Wduplicated-branches
2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
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2020-09-20 20:07 ` mpolacek at gcc dot gnu.org
@ 2020-09-20 20:29 ` sandra at gcc dot gnu.org
2020-09-20 20:32 ` mpolacek at gcc dot gnu.org
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From: sandra at gcc dot gnu.org @ 2020-09-20 20:29 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
sandra at gcc dot gnu.org changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |sandra at gcc dot gnu.org
--- Comment #4 from sandra at gcc dot gnu.org ---
Hmmm, maybe it needs to know about the other structured control flow tree nodes
I moved from cp/ to c-family/, as well as SWITCH_STMT?
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2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
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2020-09-20 20:29 ` sandra at gcc dot gnu.org
@ 2020-09-20 20:32 ` mpolacek at gcc dot gnu.org
2020-09-20 21:40 ` sandra at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2020-09-20 20:32 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I think we just want to call do_warn_duplicated_branches_r after we've lowered
control statements:
--- a/gcc/c-family/c-gimplify.c
+++ b/gcc/c-family/c-gimplify.c
@@ -533,10 +533,6 @@ c_genericize (tree fndecl)
&pset);
}
- if (warn_duplicated_branches)
- walk_tree_without_duplicates (&DECL_SAVED_TREE (fndecl),
- do_warn_duplicated_branches_r, NULL);
-
/* Genericize loops and other structured control constructs. The C++
front end has already done this in lang-specific code. */
if (!c_dialect_cxx ())
@@ -550,6 +546,10 @@ c_genericize (tree fndecl)
pop_cfun ();
}
+ if (warn_duplicated_branches)
+ walk_tree_without_duplicates (&DECL_SAVED_TREE (fndecl),
+ do_warn_duplicated_branches_r, NULL);
+
/* Dump the C-specific tree IR. */
dump_orig = get_dump_info (TDI_original, &local_dump_flags);
if (dump_orig)
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2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
` (6 preceding siblings ...)
2020-09-20 20:32 ` mpolacek at gcc dot gnu.org
@ 2020-09-20 21:40 ` sandra at gcc dot gnu.org
2020-09-23 14:05 ` mpolacek at gcc dot gnu.org
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From: sandra at gcc dot gnu.org @ 2020-09-20 21:40 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
--- Comment #6 from sandra at gcc dot gnu.org ---
Yeah, that looks like an easy fix. Thanks for tracking it down.
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2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
` (7 preceding siblings ...)
2020-09-20 21:40 ` sandra at gcc dot gnu.org
@ 2020-09-23 14:05 ` mpolacek at gcc dot gnu.org
2020-09-23 14:11 ` cvs-commit at gcc dot gnu.org
2020-09-23 14:12 ` mpolacek at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2020-09-23 14:05 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |jim at meyering dot net
--- Comment #7 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
*** Bug 97157 has been marked as a duplicate of this bug. ***
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2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
` (8 preceding siblings ...)
2020-09-23 14:05 ` mpolacek at gcc dot gnu.org
@ 2020-09-23 14:11 ` cvs-commit at gcc dot gnu.org
2020-09-23 14:12 ` mpolacek at gcc dot gnu.org
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From: cvs-commit at gcc dot gnu.org @ 2020-09-23 14:11 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Marek Polacek <mpolacek@gcc.gnu.org>:
https://gcc.gnu.org/g:c48ffe21f8f3478cf08f9442e3f973df358caf2a
commit r11-3397-gc48ffe21f8f3478cf08f9442e3f973df358caf2a
Author: Marek Polacek <polacek@redhat.com>
Date: Sun Sep 20 16:11:00 2020 -0400
c: Fix -Wduplicated-branches ICE [PR97125]
We crash here because since r11-3302 the C FE uses codes like SWITCH_STMT
in the else branches in the attached test, and inchash::add_expr in
do_warn_duplicated_branches doesn't handle these front-end codes. In
the C++ FE this works because by the time we get to
do_warn_duplicated_branches
we've already cp_genericize'd the SWITCH_STMT tree into a SWITCH_EXPR.
The fix is to call do_warn_duplicated_branches_r only after loops and other
structured control constructs have been lowered.
gcc/c-family/ChangeLog:
PR c/97125
* c-gimplify.c (c_genericize): Only call
do_warn_duplicated_branches_r
after loops and other structured control constructs have been
lowered.
gcc/testsuite/ChangeLog:
PR c/97125
* c-c++-common/Wduplicated-branches-15.c: New test.
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2020-09-20 10:30 [Bug c/97125] New: new problem with -Wduplicated-branches dcb314 at hotmail dot com
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2020-09-23 14:11 ` cvs-commit at gcc dot gnu.org
@ 2020-09-23 14:12 ` mpolacek at gcc dot gnu.org
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From: mpolacek at gcc dot gnu.org @ 2020-09-23 14:12 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97125
Marek Polacek <mpolacek at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Status|ASSIGNED |RESOLVED
Resolution|--- |FIXED
--- Comment #9 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed.
^ permalink raw reply [flat|nested] 12+ messages in thread