[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261 Bernd Edlinger changed: What|Removed |Added Status|NEW |RESOLVED Resolution|--- |FIXED --- Comment #13 from Bernd Edlinger --- Fixed.
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261 --- Comment #12 from Bernd Edlinger --- Author: edlinger Date: Mon Jan 7 17:08:51 2019 New Revision: 267653 URL: https://gcc.gnu.org/viewcvs?rev=267653=gcc=rev Log: PR c++/88261 PR c++/69338 PR c++/69696 PR c++/69697 * cp-tree.h (LOOKUP_ALLOW_FLEXARRAY_INIT): New flag value. * typeck2.c (digest_init_r): Raise an error for non-static initialization of a flexible array member. (process_init_constructor, massage_init_elt, process_init_constructor_array, process_init_constructor_record, process_init_constructor_union, process_init_constructor): Add the flags parameter and pass it thru. (store_init_value): Pass LOOKUP_ALLOW_FLEXARRAY_INIT parameter to digest_init_flags for static decls. gcc/testsuite: 2019-01-07 Bernd Edlinger PR c++/88261 PR c++/69338 PR c++/69696 PR c++/69697 * gcc.dg/array-6.c: Move from here ... * c-c++-common/array-6.c: ... to here and add some more test coverage. * g++.dg/pr69338.C: New test. * g++.dg/pr69697.C: Likewise. * g++.dg/ext/flexary32.C: Likewise. * g++.dg/ext/flexary3.C: Adjust test. * g++.dg/ext/flexary12.C: Likewise. * g++.dg/ext/flexary13.C: Likewise. * g++.dg/ext/flexary15.C: Likewise. * g++.dg/warn/Wplacement-new-size-1.C: Likewise. * g++.dg/warn/Wplacement-new-size-2.C: Likewise. * g++.dg/warn/Wplacement-new-size-6.C: Likewise. Added: trunk/gcc/testsuite/c-c++-common/array-6.c - copied, changed from r267652, trunk/gcc/testsuite/gcc.dg/array-6.c trunk/gcc/testsuite/g++.dg/ext/flexary32.C trunk/gcc/testsuite/g++.dg/pr69338.C trunk/gcc/testsuite/g++.dg/pr69697.C Removed: trunk/gcc/testsuite/gcc.dg/array-6.c Modified: trunk/gcc/cp/ChangeLog trunk/gcc/cp/cp-tree.h trunk/gcc/cp/typeck2.c trunk/gcc/testsuite/ChangeLog trunk/gcc/testsuite/g++.dg/ext/flexary12.C trunk/gcc/testsuite/g++.dg/ext/flexary13.C trunk/gcc/testsuite/g++.dg/ext/flexary15.C trunk/gcc/testsuite/g++.dg/ext/flexary3.C trunk/gcc/testsuite/g++.dg/warn/Wplacement-new-size-1.C trunk/gcc/testsuite/g++.dg/warn/Wplacement-new-size-2.C trunk/gcc/testsuite/g++.dg/warn/Wplacement-new-size-6.C
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261 Richard Biener changed: What|Removed |Added Keywords||ice-checking Priority|P3 |P1
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261 Martin Sebor changed: What|Removed |Added See Also||https://gcc.gnu.org/bugzill ||a/show_bug.cgi?id=69696 --- Comment #11 from Martin Sebor --- This looks related to pr69696.
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261
--- Comment #10 from Bernd Edlinger ---
Hmm, there are a few loose ends, where there is simply no decl.
For instance in this example:
/* PR c/5597 */
/* { dg-do compile } */
/* { dg-options "" } */
/* Verify that GCC forbids non-static initialization of
flexible array members. */
struct str { int len; char s[]; };
struct str a = { 2, "a" };
void foo()
{
static struct str d = (struct str) { 2, "d" }; /* { dg-error
"(non-static)|(near initialization)" } */
static struct str e = (struct str) { d.len, "e" }; /* { dg-error
"(non-static)|(initialization)" } */
}
$ g++ -S array-6.c
array-6.c:14:47: error: non-static initialization of a flexible array member
14 | static struct str d = (struct str) { 2, "d" }; /* { dg-error
"(non-static)|(near initialization)" } */
| ^
array-6.c:15:51: error: non-static initialization of a flexible array member
15 | static struct str e = (struct str) { d.len, "e" }; /* { dg-error
"(non-static)|(initialization)" } */
| ^
the patch prints an error, but digest_init_r is called from
finish_compound_literal:
2830 compound_literal = digest_init_flags (type, compound_literal,
LOOKUP_NORMAL,
2831complain, NULL_TREE);
So here it is impossible to tell which decl is going to be initialized,
because this is called drectly from the parser (cp_parser_postfix_expression).
However the C-FE does also not have a decl here, and I think I cannot do
much about that:
$ gcc -S array-6.c
array-6.c: In function 'foo':
array-6.c:14:43: error: non-static initialization of a flexible array member
14 | static struct str d = (struct str) { 2, "d" }; /* { dg-error
"(non-static)|(near initialization)" } */
| ^~~
array-6.c:14:43: note: (near initialization for '(anonymous)')
array-6.c:15:47: error: non-static initialization of a flexible array member
15 | static struct str e = (struct str) { d.len, "e" }; /* { dg-error
"(non-static)|(initialization)" } */
| ^~~
array-6.c:15:47: note: (near initialization for '(anonymous)')
array-6.c:15:25: error: initializer element is not constant
15 | static struct str e = (struct str) { d.len, "e" }; /* { dg-error
"(non-static)|(initialization)" } */
| ^
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261 --- Comment #9 from Jeffrey A. Law --- Thanks for running with this Bernd. My brain was too mushy last night to get anywhere. I agree that digest_init_r seems like the right place to try and address this problem. ISTM we could either add the DECL as a parameter or pass in some kind of state to indicate if it's automatic or static. I've got no strong opinion on which of those two approaches is best -- but Jason will have the final call here.
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261
Bernd Edlinger changed:
What|Removed |Added
CC||bernd.edlinger at hotmail dot
de
--- Comment #8 from Bernd Edlinger ---
Interesting: above patch adds an error in
gcc/testsuite/g++.dg/warn/Wplacement-new-size-1.C
where this is no ICE but only wrong code (I modified the test case
a bit to demonstrate the Problem):
$ cat Wplacement-new-size-1.C
// PR c++/69662 - -Wplacement-new on allocated one element array members
// Exercising the more permissive -Wplacement-new=1. The difference
// between -Wplacement-new=1 is denoted by "no warning at level 1" in
// the comments below.
// { dg-do compile }
// { dg-options "-Wno-pedantic -Wplacement-new=1" }
typedef __typeof__ (sizeof 0) size_t;
void* operator new (size_t, void *p) { return p; }
void* operator new[] (size_t, void *p) { return p; }
struct Ax { char n, a []; };
typedef __INT16_TYPE__ Int16;
char xx[3];
void fAx2 ()
{
Ax ax2 = { 1, { 2, 3 } };
new (ax2.a) Int16(123);
__builtin_memcpy(xx, , 3);
}
int main()
{
fAx2 ();
}
$ g++ -O2 Wplacement-new-size-1.C
$ ./a.out
Segmentation fault (core dumped)
$ g++ -S -O2 Wplacement-new-size-1.C
$ cat Wplacement-new-size-1.s
.file "Wplacement-new-size-1.C"
.text
.p2align 4
.globl _ZnwmPv
.type _ZnwmPv, @function
_ZnwmPv:
.LFB0:
.cfi_startproc
movq%rsi, %rax
ret
.cfi_endproc
.LFE0:
.size _ZnwmPv, .-_ZnwmPv
.p2align 4
.globl _ZnamPv
.type _ZnamPv, @function
_ZnamPv:
.LFB5:
.cfi_startproc
movq%rsi, %rax
ret
.cfi_endproc
.LFE5:
.size _ZnamPv, .-_ZnamPv
.section.rodata
.LC0:
.byte 1
.byte 2
.byte 3
.text
.p2align 4
.globl _Z4fAx2v
.type _Z4fAx2v, @function
_Z4fAx2v:
.LFB2:
.cfi_startproc
movzbl .LC0(%rip), %eax
movb%al, -1(%rsp)
movl$123, %eax
movw%ax, (%rsp)
movzwl -1(%rsp), %eax
movw%ax, xx(%rip)
movzbl 1(%rsp), %eax
movb%al, xx+2(%rip)
ret
.cfi_endproc
.LFE2:
.size _Z4fAx2v, .-_Z4fAx2v
.section.text.startup,"ax",@progbits
.p2align 4
.globl main
.type main, @function
main:
.LFB3:
.cfi_startproc
movzbl .LC0(%rip), %eax
movb%al, -1(%rsp)
movl$123, %eax
movw%ax, (%rsp)
movzwl -1(%rsp), %eax
movw%ax, xx(%rip)
movzbl 1(%rsp), %eax
movb%al, xx+2(%rip)
xorl%eax, %eax
ret
.cfi_endproc
.LFE3:
.size main, .-main
.globl xx
.bss
.type xx, @object
.size xx, 3
xx:
.zero 3
.ident "GCC: (GNU) 9.0.0 20181209 (experimental)"
.section.note.GNU-stack,"",@progbits
So Ax2 has actually only 1 Byte space on the stack,
and "new (ax2.a) Int16(123);"
overwrites the return stack
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261 --- Comment #7 from Bernd Edlinger --- Created attachment 45238 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=45238=edit untested patch
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261
--- Comment #6 from Bernd Edlinger ---
(In reply to Jeffrey A. Law from comment #5)
> Right, but we're not supposed to ICE, even on invalid code.
Yes, ideed.
I think what would be needed is adding this C-error to the C++FE:
array-6.c: In function 'foo':
array-6.c:12:23: error: non-static initialization of a flexible array member
12 | struct str b = { 2, "b" };
| ^~~
array-6.c:12:23: note: (near initialization for 'b')
the error depends on TREE_STATIC (decl);
the data flow in the C-FE is just weird,
see "require_constant_value", a global value holds that bit...
I believe the right place to add in the C++ FE is probably
at where this C++ -Wpedantic warning is emitted,
array-6.c:12:27: warning: initialization of a flexible array member
[-Wpedantic]
12 | struct str b = { 2, "b" };
| ^
unfortunately that is in digest_init_r and that does not have
access to TREE_STATIC (decl);
In case the object is static, that should be a warning, but in case
of an automatic object it should be a error, that would prevent the ICE.
Either one need to a static variable like the C-FE or pass the decl
from store_init_value and probably other places too into the digest_init
and digest_init_flags.
Well, it will probably be better to add an additional decl parameter.
Thoughts?
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261 Jeffrey A. Law changed: What|Removed |Added CC||law at redhat dot com --- Comment #5 from Jeffrey A. Law --- Right, but we're not supposed to ICE, even on invalid code.
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261
--- Comment #4 from Bernd Edlinger ---
For G++ versions, where this was accepted with -fpermissive, the code was
wrong:
struct str { int len; char s[]; };
int foo()
{
struct str b = { 2, "b" };
return sizeof(b);
}
=>
movl$4, %eax
ret
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261
--- Comment #3 from Martin Sebor ---
The ICE only affects C++. G++ 8 and prior accept the code with just a pedantic
warning:
$ cat pr88261.C && gcc -O2 -S -Wall -Wextra -Wpedantic pr88261.C
struct str { int len; char s[]; };
void foo()
{
struct str c = { 2, "c" };
}
pr88261.C:1:30: warning: ISO C++ forbids flexible array member ‘s’ [-Wpedantic]
struct str { int len; char s[]; };
^
pr88261.C: In function ‘void foo()’:
pr88261.C:5:27: warning: initialization of a flexible array member [-Wpedantic]
struct str c = { 2, "c" };
^
pr88261.C:5:14: warning: unused variable ‘c’ [-Wunused-variable]
struct str c = { 2, "c" };
^
But G++ rejects the code if it's changed like below so the C++ front-end should
probably reject it regardless of whether or not the struct is used.
int foo()
{
struct str c = { 2, "c" };
return c.s[0];
}
pr88261.C:1:30: warning: ISO C++ forbids flexible array member ‘s’ [-Wpedantic]
struct str { int len; char s[]; };
^
pr88261.C: In function ‘int foo()’:
pr88261.C:5:27: warning: initialization of a flexible array member [-Wpedantic]
struct str c = { 2, "c" };
^
pr88261.C:5:14: error: invalid use of array with unspecified bounds
struct str c = { 2, "c" };
^
pr88261.C:5:14: error: invalid use of array with unspecified bounds
The again, G++ 5 accepts the modified example above with -fpermissive:
pr88261.C:5:27: warning: initializer-string for array of chars is too long
[-fpermissive]
struct str c = { 2, "c" };
^
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261 --- Comment #2 from Jakub Jelinek --- Started with r264147.
[Bug c++/88261] [9 Regression] ICE: verify_gimple failed (error: non-trivial conversion at assignment)
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88261
Richard Biener changed:
What|Removed |Added
Keywords||accepts-invalid
Status|UNCONFIRMED |NEW
Last reconfirmed||2018-11-29
Target Milestone|--- |9.0
Ever confirmed|0 |1
--- Comment #1 from Richard Biener ---
Confirmed. GCC 8 diagnoses it as
array-6.c: In function ‘void foo()’:
array-6.c:15:14: error: invalid use of array with unspecified bounds
struct str c = { 2, "c" }; /* { dg-error "(non-static)|(near
initialization)" } */
^
array-6.c:15:14: error: invalid use of array with unspecified bounds
array-6.c:16:14: error: invalid use of array with unspecified bounds
struct str d = (struct str) { 2, "d" }; /* { dg-error "(non-static)|(near
initialization)" } */
^
array-6.c:16:14: error: invalid use of array with unspecified bounds
array-6.c:17:14: error: invalid use of array with unspecified bounds
struct str e = (struct str) { d.len, "e" }; /* { dg-error
"(non-static)|(initialization)" } */
^
array-6.c:17:14: error: invalid use of array with unspecified bounds
