[Bug target/64417] New: [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[Bug target/64417] New: [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[olegendo at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64417

            Bug ID: 64417
           Summary: [SH] FAIL: gcc.c-torture/compile/pr28865.c   -O0
                    (test for excess errors)
           Product: gcc
           Version: 5.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: target
          Assignee: unassigned at gcc dot gnu.org
          Reporter: olegendo at gcc dot gnu.org

On SH, the test case 

struct var_len
{
  int field1;
  const char field2[];
};

static const struct var_len var_array[] = 
{
  { 1, "Long exposure noise reduction" },
  { 2, "Shutter/AE lock buttons" },
  { 3, "Mirror lockup" }
};

without optimization compiles to:
    .little
    .section    .rodata
    .align 2
    .type    _var_array, @object
    .size    _var_array, 12
_var_array:
    .long    1
    .string    "Long exposure noise reduction"
    .long    2
    .string    "Shutter/AE lock buttons"
    .long    3
    .string    "Mirror lockup"
    .ident    "GCC: (GNU) 5.0.0 20141226 (experimental)"

The structs in the array are misaligned.  Either the struct size has to be
aligned to 4 bytes (adding '\0' chars to the strings or inserting .align 2) or
the 32 bit values have to be output as byte arrays.

[Bug c/64417] [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[schwab@linux-m68k.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64417

Andreas Schwab <schwab@linux-m68k.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|target                      |c

--- Comment #1 from Andreas Schwab <schwab@linux-m68k.org> ---
That should be rejected, since array element types may not be incomplete.

[Bug c/64417] [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64417

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |mpolacek at gcc dot gnu.org

--- Comment #2 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I tend to agree.  In other words,

struct foo { int x; char y[]; };

struct foo a1[] = { { 1, "a" } };
struct foo a2[] = { { 1, { "a" } } };
struct foo a3[] = { 1, "a" };
struct foo b1[] = { { 1, { 'a', '\0' } } };
struct foo b2[] = { 1, { 'a', '\0' } };

We reject b1 and b2, but should also reject a[123].

[Bug c/64417] [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64417

--- Comment #3 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
I have a patch for rejecting such code, but the question is if it is desirable
to not accept that code, since e.g. glibc used to (?) misuse this feature.

[Bug c/64417] [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[schwab@linux-m68k.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64417

--- Comment #4 from Andreas Schwab <schwab@linux-m68k.org> ---
The glibc sources never contained such an array of incomplete type.  The
example in bug28865#c3 has nothing to do with glibc.

[Bug c/64417] [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64417

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |ASSIGNED
   Last reconfirmed|                            |2015-01-06
           Assignee|unassigned at gcc dot gnu.org      |mpolacek at gcc dot gnu.org
   Target Milestone|---                         |5.0
     Ever confirmed|0                           |1

--- Comment #5 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Great, thanks.

[Bug c/64417] [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64417

--- Comment #6 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Author: mpolacek
Date: Wed Jan  7 08:19:48 2015
New Revision: 219278

URL: https://gcc.gnu.org/viewcvs?rev=219278&root=gcc&view=rev
Log:
    PR c/64417
c/
    * c-typeck.c (process_init_element): Disallow initialization of
    a flexible array member with a string constant if the structure
    is in an array.
testsuite/
    * gcc.c-torture/compile/pr28865.c: Add dg-errors.
    * gcc.dg/pr64417.c: New test.

Added:
    trunk/gcc/testsuite/gcc.dg/pr64417.c
Modified:
    trunk/gcc/c/ChangeLog
    trunk/gcc/c/c-typeck.c
    trunk/gcc/testsuite/ChangeLog
    trunk/gcc/testsuite/gcc.c-torture/compile/pr28865.c

[Bug c/64417] [SH] FAIL: gcc.c-torture/compile/pr28865.c -O0 (test for excess errors)

[mpolacek at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64417

Marek Polacek <mpolacek at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED

--- Comment #7 from Marek Polacek <mpolacek at gcc dot gnu.org> ---
Fixed.