[Bug c/19342] New: internal compiler error: in common_type, at c-typeck.c:490

[Bug c/19342] New: internal compiler error: in common_type, at c-typeck.c:490

[aj at gcc dot gnu dot org]

The following error occured on all 4 architectures where I tested it (x86-64, 
x86, ia64, PPC), here're the details for i686 (output is from x86_64-linux-gnu 
GCC with -m32 for debugging purposes): 
 
/opt/gcc/4.0-devel/libexec/gcc/x86_64-suse-linux-gnu/4.0.0/cc1 -fpreprocessed 
db.i -quiet -dumpbase db.c -march=i686 -mtune=i686 -auxbase-strip db.o -O2 
-Wall -W -Wall -Wno-unused -W -version -fmessage-length=0 -fno-strict-aliasing 
-o db.s -m32 
GNU C version 4.0.0 20050108 (experimental) (x86_64-suse-linux-gnu) 
        compiled by GNU C version 4.0.0 20050108 (experimental). 
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096 
db.i: In function ?write_lease?: 
db.i:11708: internal compiler error: in common_type, at c-typeck.c:490 
Please submit a full bug report, 
with preprocessed source if appropriate. 
See <URL:http://gcc.gnu.org/bugs.html> for instructions.

-- 
           Summary:  internal compiler error: in common_type, at c-
                    typeck.c:490
           Product: gcc
           Version: 4.0.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P2
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: aj at gcc dot gnu dot org
                CC: gcc-bugs at gcc dot gnu dot org
 GCC build triplet: *
  GCC host triplet: *
GCC target triplet: *


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] internal compiler error: in common_type, at c-typeck.c:490

[aj at gcc dot gnu dot org]

------- Additional Comments From aj at gcc dot gnu dot org  2005-01-09 07:10 -------
Created an attachment (id=7910)
 --> (http://gcc.gnu.org/bugzilla/attachment.cgi?id=7910&action=view)
Preprocessed source file - i386 compilation


-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] internal compiler error: in common_type, at c-typeck.c:490

[aj at gcc dot gnu dot org]

------- Additional Comments From aj at gcc dot gnu dot org  2005-01-09 07:15 -------
Btw. error did not occur with GCC CVS from 20050103 and the next one tested 
was from 20050108. 

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
            Summary| internal compiler error: in|internal compiler error: in
                   |common_type, at c-          |common_type, at c-
                   |typeck.c:490                |typeck.c:490


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] internal compiler error: in common_type, at c-typeck.c:490

[steven at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|UNCONFIRMED                 |NEW
     Ever Confirmed|                            |1
  GCC build triplet|*                           |
   GCC host triplet|*                           |
 GCC target triplet|*                           |
   Last reconfirmed|0000-00-00 00:00:00         |2005-01-09 10:50:20
               date|                            |


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] internal compiler error: in common_type, at c-typeck.c:490

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-01-09 11:12 -------
typedef enum { 
  ORANGE, 
  GRAPE 
} fruit; 
 
struct list { 
  fruit __attribute__ ((mode (__byte__))) elt; 
  fruit __attribute__ ((mode (__byte__))) next_elt; 
}; 
 
 
void bar (void); 
 
void 
foo (struct list *l, int a) 
{ 
 if (l->elt != l->next_elt) 
   bar(); 
} 
 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[steven at gcc dot gnu dot org]

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
           Severity|normal                      |critical
           Keywords|                            |ice-on-valid-code
      Known to fail|                            |4.0.0
      Known to work|                            |3.3.4 3.4.2
           Priority|P2                          |P1
            Summary|internal compiler error: in |[4.0 regression] ICE in
                   |common_type, at c-          |common_type, at c-
                   |typeck.c:490                |typeck.c:490
   Target Milestone|---                         |4.0.0


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[pinskia at gcc dot gnu dot org]

------- Additional Comments From pinskia at gcc dot gnu dot org  2005-01-09 15:35 -------
The only obvious change which caused this would be:
2005-01-07  Jakub Jelinek  <jakub@redhat.com>

        * c-common.c (handle_mode_attribute): For ENUMERAL_TYPE, also copy
        TYPE_MODE.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |jakub at redhat dot com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[jakub at gcc dot gnu dot org]

------- Additional Comments From jakub at gcc dot gnu dot org  2005-01-10 11:28 -------
Yes, my patch clearly triggers this (changing silent miscompilation of the
code into an ICE).
The problem is that common_type doesn't handle ENUMERAL_TYPEs, so probably
shorten_compare should made sure it doesn't get passed down.
The difference is that while previously shorten_compare was passed CONVERT_EXPRs,
created in convert.c's
          /* If the precision of the EXPR's type is K bits and the
             destination mode has more bits, and the sign is changing,
             it is not safe to use a NOP_EXPR.  For example, suppose
             that EXPR's type is a 3-bit unsigned integer type, the
             TYPE is a 3-bit signed integer type, and the machine mode
             for the types is 8-bit QImode.  In that case, the
             conversion necessitates an explicit sign-extension.  In
             the signed-to-unsigned case the high-order bits have to
             be cleared.  */
          if (TYPE_UNSIGNED (type) != TYPE_UNSIGNED (TREE_TYPE (expr))
              && (TYPE_PRECISION (TREE_TYPE (expr))
                  != GET_MODE_BITSIZE (TYPE_MODE (TREE_TYPE (expr)))))
            code = CONVERT_EXPR;
          else
            code = NOP_EXPR;

          return build1 (code, type, expr);
now, when the mode is fixed, we pass NOP_EXPR.  So, before my patch primop{0,1}'s
type was int while now it is that enum __attribute__((mode(byte))).

Now, C++ common_type handles ENUMERAL_TYPEs, so I don't think it is appropriate
to special case ENUMERAL_TYPEs in shorten_compare which is shared between
C/C++/ObjC.  So perhaps add code to handle ENUMERAL_TYPEs in C common_type?

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[jakub at gcc dot gnu dot org]

------- Additional Comments From jakub at gcc dot gnu dot org  2005-01-18 13:35 -------
Note that GCC 3.4's common_type handled ENUMERAL_TYPEs.
This was removed in PR13519 patch.

-- 
           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |joseph at codesourcery dot
                   |                            |com


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[joseph at codesourcery dot com]

------- Additional Comments From joseph at codesourcery dot com  2005-01-18 14:39 -------
Subject: Re:  [4.0 regression] ICE in common_type, at c-typeck.c:490

On Tue, 18 Jan 2005, jakub at gcc dot gnu dot org wrote:

> Note that GCC 3.4's common_type handled ENUMERAL_TYPEs.
> This was removed in PR13519 patch.

Indeed, previously common_type did not have a well-defined purpose or 
interface and tried to do three different things.  Now it is well-defined:

/* Return the common type for two arithmetic types under the usual
   arithmetic conversions.  The default conversions have already been
   applied, and enumerated types converted to their compatible integer
   types.

So under the interface currently specified it shouldn't receive enumerated 
types.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[jakub at gcc dot gnu dot org]

------- Additional Comments From jakub at gcc dot gnu dot org  2005-01-18 18:28 -------
But did this change for all frontends or just C?
In the code in question common_type is used by code common to C and C++.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[joseph at codesourcery dot com]

------- Additional Comments From joseph at codesourcery dot com  2005-01-18 20:10 -------
Subject: Re:  [4.0 regression] ICE in common_type, at c-typeck.c:490

On Tue, 18 Jan 2005, jakub at gcc dot gnu dot org wrote:

> But did this change for all frontends or just C?
> In the code in question common_type is used by code common to C and C++.

I think the underlying problems there are (1) undesigned ad hoc sharing 
between the front ends, (2) this language-specific function being called 
from what's essentially an optimization, not only on types that appear 
directly in the source as operands to which usual arithmetic conversions 
are to be applies, (3) this optimization happens at this stage at all, 
rather than later in a language-independent way that doesn't need to call 
back into front ends.  Short term, allowing enumerated types in 
common_type for C for this special case would make sense as a fix for this 
bug.



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-01-28 00:16 -------
Jakub, what's the plan with this one, are you going to fix it? 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[jakub at gcc dot gnu dot org]

------- Additional Comments From jakub at gcc dot gnu dot org  2005-01-28 06:26 -------
Patch here <http://gcc.gnu.org/ml/gcc-patches/2005-01/msg01218.html>.
This one fixes the testcase, but while writing a larger testcase I found
other unrelated bugs that aren't fixed yet.

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[steven at gcc dot gnu dot org]

------- Additional Comments From steven at gcc dot gnu dot org  2005-02-08 23:52 -------
Jakub, so why not get your patch of comment #11 in first, and worry about the, 
as you say yourself, unrelated bugs later? 
 
 

-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[cvs-commit at gcc dot gnu dot org]

------- Additional Comments From cvs-commit at gcc dot gnu dot org  2005-02-10 12:19 -------
Subject: Bug 19342

CVSROOT:	/cvs/gcc
Module name:	gcc
Changes by:	jakub@gcc.gnu.org	2005-02-10 12:18:52

Modified files:
	gcc            : ChangeLog c-typeck.c 
	gcc/testsuite  : ChangeLog 
Added files:
	gcc/testsuite/gcc.c-torture/execute: 20050119-1.c 

Log message:
	PR c/19342
	* c-typeck.c (common_type): New routine.  Old common_type renamed
	to...
	(c_common_type): ...this.
	(build_conditional_expr, build_binary_op): Use c_common_type instead
	of common_type.
	
	* gcc.c-torture/execute/20050119-1.c: New test.

Patches:
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/ChangeLog.diff?cvsroot=gcc&r1=2.7429&r2=2.7430
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/c-typeck.c.diff?cvsroot=gcc&r1=1.417&r2=1.418
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/ChangeLog.diff?cvsroot=gcc&r1=1.5014&r2=1.5015
http://gcc.gnu.org/cgi-bin/cvsweb.cgi/gcc/gcc/testsuite/gcc.c-torture/execute/20050119-1.c.diff?cvsroot=gcc&r1=NONE&r2=1.1



-- 


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342

[Bug c/19342] [4.0 regression] ICE in common_type, at c-typeck.c:490

[jakub at gcc dot gnu dot org]

------- Additional Comments From jakub at gcc dot gnu dot org  2005-02-10 12:20 -------
Fixed.

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


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=19342