[PR43082] ICE in tree check: expected class 'type', have 'exceptional' (error_mark) in useless_type_conversion_p

[Steven Sroka]

Binary package hint: gcc-4.4

I was just compiling a simple C programming through Netbeans 6.8 when Apport popped up saying cc(1) crashed.

ProblemType: Crash
Architecture: amd64
CheckboxSubmission: 8fd4227425960116f6d27ff3861ffb00
CheckboxSystem: e704f33cc0866ff0f0256a33de39ea1c
Date: Fri Feb 12 12:41:53 2010
DistroRelease: Ubuntu 9.10
ExecutablePath: /usr/lib/gcc/x86_64-linux-gnu/4.4.1/cc1
InstallationMedia: Ubuntu 9.10 "Karmic Koala" - Release amd64 (20091027)
LiveMediaBuild: Linux Mint KDE64 CE 8 "Helena" - Release x86_64 (20100209.1)
NonfreeKernelModules: fglrx
Package: cpp-4.4 4.4.1-4ubuntu9
ProcVersionSignature: Ubuntu 2.6.31-19.56-generic
SourcePackage: gcc-4.4
Uname: Linux 2.6.31-19-generic x86_64

[Matthias Klose (doko)]

seen with 4.3, 4.4 and trunk:

$ gcc -c main.i
main.c: In function 'main':
main.c:22:5: error: void value not ignored as it ought to be
main.c:22:5: error: void value not ignored as it ought to be
main.c:22:8: internal compiler error: tree check: expected class 'type', have 'exceptional' (error_mark) in useless_type_conversion_p, at tree-ssa.c:1233
Please submit a full bug report,
with preprocessed source if appropriate.
See <file:///usr/share/doc/gcc-snapshot/README.Bugs> for instructions.

[Matthias Klose (doko)]

Created attachment 19878
preprocessed source

[Matthias Klose (doko)]

the bug is in your code, however gcc shouldn't ICE.

$ gcc -c main.i
main.c: In function 'main':
main.c:22:5: error: void value not ignored as it ought to be
main.c:22:5: error: void value not ignored as it ought to be

[Rguenth (rguenth)]

We get

6493 STRIP_USELESS_TYPE_CONVERSION (*expr_p);
(gdb) call debug_tree (*expr_p)
 <nop_expr 0x7ffff5b99150
    type <boolean_type 0x7ffff7ee4888 _Bool public unsigned QI
        size <integer_cst 0x7ffff7ed2730 constant 8>
        unit size <integer_cst 0x7ffff7ed2758 constant 1>
        align 8 symtab 0 alias set -1 canonical type 0x7ffff7ee4888 precision 1 min <integer_cst 0x7ffff7ed2b68 0> max <integer_cst 0x7ffff7ed2bb8 1>>

    arg 0 <cond_expr 0x7ffff5b48280 type <error_mark 0x7ffff7edab70>

The FEs shouldn't feed us random crap really ...

[Pinskia (pinskia)]

Reduced testcase:
int main(void)
{
    int gpf;
    if(gpf ? (void) (0) : f ()) ;
}
--- CUT ---
Looking into it.

[Pinskia (pinskia)]

I get:
t1.c:4:7: internal compiler error: tree check: expected class ‘type’, have ‘exceptional’ (error_mark) in get_narrower, at tree.c:7654

Now.

[Pinskia (pinskia)]

I have a patch to c_common_truthvalue_conversion which fixes this issue.

[Pinskia (pinskia)]

No longer working on this one.

[Matthias Klose (doko)]

trunk 20100918 fails with:

gcc -g -O0 -c foo.c
foo.c: In function 'main':
foo.c:4:5: error: void value not ignored as it ought to be
foo.c:4:5: error: void value not ignored as it ought to be
foo.c:4:7: internal compiler error: tree check: expected class 'type', have 'exceptional' (error_mark) in get_narrower, at tree.c:7856
Please submit a full bug report,
with preprocessed source if appropriate.

[Nicola-gcc (nicola-gcc)]

This is a regression since my stock RedHat gcc 4.1.2 compiler doesn't ICE.

I have a patch that should address Joseph's comments to Andrew's original
patch. I'll submit it once it's finished testing.

Thanks

[Nicola-gcc (nicola-gcc)]

Author: nicola
Date: Thu Jan 27 02:09:13 2011
New Revision: 169319

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=169319
Log:
In gcc/:
2011-01-26 Nicola Pero <email address hidden>

 PR c/43082
 * c-typeck.c (c_objc_common_truthvalue_conversion): If we are
 passed a VOID_TYPE expression, immediately emit an error and
 return error_mark_node.

In gcc/testsuite/:
2011-01-26 Nicola Pero <email address hidden>
     Andrew Pinski <email address hidden>

 PR c/43082
 * gcc.dg/pr43082.c: New.

Added:
    trunk/gcc/testsuite/gcc.dg/pr43082.c
Modified:
    trunk/gcc/ChangeLog
    trunk/gcc/c-typeck.c
    trunk/gcc/testsuite/ChangeLog

[Nicola-gcc (nicola-gcc)]

Fixed in GCC trunk/4.6.0.

Thanks

[Dnovillo (dnovillo)]

Author: dnovillo
Date: Wed Feb 2 17:55:55 2011
New Revision: 169639

URL: http://gcc.gnu.org/viewcvs?root=gcc&view=rev&rev=169639
Log:
In gcc/:
2011-01-26 Nicola Pero <email address hidden>

 PR c/43082
 * c-typeck.c (c_objc_common_truthvalue_conversion): If we are
 passed a VOID_TYPE expression, immediately emit an error and
 return error_mark_node.

In gcc/testsuite/:
2011-01-26 Nicola Pero <email address hidden>
     Andrew Pinski <email address hidden>

 PR c/43082
 * gcc.dg/pr43082.c: New.

Added:
    branches/google/integration/gcc/testsuite/gcc.dg/pr43082.c
Modified:
    branches/google/integration/gcc/ChangeLog
    branches/google/integration/gcc/c-typeck.c
    branches/google/integration/gcc/testsuite/ChangeLog