[Bug c++/23426] New: partial fix too large array problem

[Bug c++/23426] New: partial fix too large array problem

[wilson at gcc dot gnu dot org]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1529 bytes --]

A testcase that has an array larger than half the address space and smaller than
the address space will trigger an abort in tree_int_cst_low.

The problem here is that we have a TREE_OVERFLOW (TYPE_SIZE (...)) check in the
C++ front end.  This no longer works now that TYPE_SIZE is computed as
bitsizetype which has extra precision.  We must use TYPE_SIZE_UNIT instead. 
This is trivial to fix, but now the testcase gets two errors instead of the
expected one error.  I don't know if this is intended behaviour, or whether this
is a latent bug in the C++ front end.  Either way, my testcase doesn't work for
the testsuite because of this problem, so a C++ front end maintainer will have
to decide what to do.

Result without the patch
large-size-array.cc: In function ‘int main()’:
large-size-array.cc:17: internal compiler error: in tree_low_cst, at tree.c:4270

Result with the patch
large-size-array.cc: In function ‘int main()’:
large-size-array.cc:19: error: size of array ‘a’ is too large
large-size-array.cc:20: error: ‘a’ was not declared in this scope

Both of these results are wrong.

-- 
           Summary: partial fix too large array problem
           Product: gcc
           Version: 4.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c++
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: wilson at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] partial fix too large array problem

[wilson at gcc dot gnu dot org]

------- Additional Comments From wilson at gcc dot gnu dot org  2005-08-16 18:45 -------
Created an attachment (id=9504)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=9504&action=view)
Patch to partially fix problem with too large arrays.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] partial fix too large array problem

[wilson at gcc dot gnu dot org]

------- Additional Comments From wilson at gcc dot gnu dot org  2005-08-16 18:46 -------
Created an attachment (id=9505)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=9505&action=view)
Testcase for too large array problem.


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] [4.0/4.1 Regression] partial fix too large array problem

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-08-17 02:40 -------
Confirmed.  A regression from 3.4.0.

Note there is a typo in the test, USHORT_MAX should be USHRT_MAX.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
           Keywords|                            |ice-on-invalid-code
   Last reconfirmed|0000-00-00 00:00:00         |2005-08-17 02:40:11
               date|                            |
            Summary|partial fix too large array |[4.0/4.1 Regression] partial
                   |problem                     |fix too large array problem
   Target Milestone|---                         |4.0.2


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] [4.0/4.1 Regression] partial fix too large array problem

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-08-18 15:59 -------
*** Bug 23461 has been marked as a duplicate of this bug. ***

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |pete at void dot printf dot
                   |                            |net


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] [4.0/4.1 Regression] partial fix too large array problem

[mmitchel at gcc dot gnu dot org]

------- Additional Comments From mmitchel at gcc dot gnu dot org  2005-08-22 05:03 -------
I think the knock-on error message is a latent bug in the C++ front end, so your
patch is fine.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] [4.0/4.1 Regression] partial fix too large array problem

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-08-22 23:56 -------
Subject: Bug 23426

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	wilson@gcc.gnu.org	2005-08-22 23:56:30

Modified files:
	gcc/cp         : ChangeLog 

Log message:
	Correct PR number in last patch checked in.
	PR tree-optimization/23426
	* decl.c (grokdeclarator): Use TYPE_SIZE_UNIT not TYPE_SIZE for
	array size check.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&r1=1.4855&r2=1.4856



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] [4.0/4.1 Regression] partial fix too large array problem

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-08-23 00:08 -------
Subject: Bug 23426

CVSROOT:	/cvs/gcc
Module name:	gcc
Branch: 	gcc-4_0-branch
Changes by:	wilson@gcc.gnu.org	2005-08-23 00:07:48

Modified files:
	gcc/cp         : ChangeLog decl.c 

Log message:
	Partial fix for too large array problem.
	PR tree-optimization/23426
	* decl.c (grokdeclarator): Use TYPE_SIZE_UNIT not TYPE_SIZE for
	array size check.
	Backport from mainline
	2005-06-14  Roger Sayle  <roger@eyesopen.com>
	* decl.c (grokdeclarator): Only check TREE_OVERFLOW on INTEGER_CST.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/ChangeLog.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.4648.2.79&r2=1.4648.2.80
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/cp/decl.c.diff?cvsroot=gcc&only_with_tag=gcc-4_0-branch&r1=1.1371.2.18&r2=1.1371.2.19



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] [4.0/4.1 Regression] partial fix too large array problem

[wilson at gcc dot gnu dot org]

------- Additional Comments From wilson at gcc dot gnu dot org  2005-08-23 00:10 -------
I've added my patch to mainline and the gcc-4.0.x branch, but there is still the
problem that my testcase generates two errors when it should only generate one.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] [4.0/4.1 Regression] Too large array problem gives two error message

[pinskia at gcc dot gnu dot org]

[-- Warning: decoded text below may be mangled, UTF-8 assumed --]
[-- Attachment #1: Type: text/plain, Size: 1491 bytes --]


------- Additional Comments From pinskia at gcc dot gnu dot org  2005-08-23 11:44 -------
earth:~>gcc t.cc
t.cc: In function ‘int main()’:
t.cc:19: error: size of array ‘a’ is too large
t.cc:20: error: ‘a’ was not declared in this scope
earth:~>~/ia32_linux_gcc3_4/bin/gcc t.cc
t.cc: In function `int main()':
t.cc:19: error: size of variable 'a' is too large
earth:~>gcc -v
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: /home/peshtigo/pinskia/src/gnu/gcc/src/configure --target=i686-pc-linux-gnu --
host=i686-pc-linux-gnu --enable-__cxa_atexit --enable-languages=c++,objc,java,f95 --prefix=/
home/gates/pinskia/linux --enable-threads=posix --enable-shared
Thread model: posix
gcc version 4.1.0 20050823 (experimental)

So the error message is also a regression but that makes this minor as the first error message is 
correct.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |minor
           Keywords|ice-on-invalid-code         |diagnostic
      Known to fail|                            |4.0.0 4.1.0
      Known to work|                            |3.4.0
            Summary|[4.0/4.1 Regression] partial|[4.0/4.1 Regression] Too
                   |fix too large array problem |large array problem gives
                   |                            |two error message


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426

[Bug c++/23426] [4.0/4.1 Regression] Too large array problem gives two error message

[mmitchel at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|4.0.2                       |4.0.3


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=23426