[Bug c/101195] New: ICE: in tree_to_uhwi, at tree.c:6324

[Bug c/101195] New: ICE: in tree_to_uhwi, at tree.c:6324

[cnsun at uwaterloo dot ca]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101195

            Bug ID: 101195
           Summary: ICE: in tree_to_uhwi, at tree.c:6324
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
          Assignee: unassigned at gcc dot gnu.org
          Reporter: cnsun at uwaterloo dot ca
  Target Milestone: ---

$ gcc-trunk -v
Using built-in specs.
COLLECT_GCC=gcc-trunk
COLLECT_LTO_WRAPPER=/scratch/software/gcc-trunk/libexec/gcc/x86_64-pc-linux-gnu/12.0.0/lto-wrapper
Target: x86_64-pc-linux-gnu
Configured with: /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/configure
--enable-languages=c,c++,lto --enable-checking-yes --enable-multiarch
--prefix=/scratch/software/gcc-trunk --disable-bootstrap
Thread model: posix
Supported LTO compression algorithms: zlib
gcc version 12.0.0 20210624 (experimental) [master revision
:e518ee6cd:fcf617f0d2a5a1b624718e07d7b219cb0234436f] (GCC)

$ cat mutant.c
test_eh_return_data_regno() {
  volatile res = __builtin_eh_return_data_regno(-42.);
}

$ gcc-trunk  mutant.c
mutant.c:1:1: warning: return type defaults to ‘int’ [-Wimplicit-int]
    1 | test_eh_return_data_regno() {
      | ^~~~~~~~~~~~~~~~~~~~~~~~~
mutant.c: In function ‘test_eh_return_data_regno’:
mutant.c:2:12: warning: type defaults to ‘int’ in declaration of ‘res’
[-Wimplicit-int]
    2 |   volatile res = __builtin_eh_return_data_regno(-42.);
      |            ^~~
during RTL pass: expand
mutant.c:2:18: internal compiler error: in tree_to_uhwi, at tree.c:6324
    2 |   volatile res = __builtin_eh_return_data_regno(-42.);
      |                  ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
0x7c7c7e tree_to_uhwi(tree_node const*)
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/tree.c:6324
0x7c7c7e tree_to_uhwi(tree_node const*)
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/tree.c:6322
0xb50537 expand_builtin_eh_return_data_regno(tree_node*)
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/except.c:2170
0xa222f6 expand_builtin(tree_node*, rtx_def*, rtx_def*, machine_mode, int)
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/builtins.c:10409
0xb7366c expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/expr.c:11439
0xb7e018 store_expr(tree_node*, rtx_def*, int, bool, bool)
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/expr.c:5994
0xb7f65f expand_assignment(tree_node*, tree_node*, bool)
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/expr.c:5729
0xa4cb8b expand_call_stmt
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/cfgexpand.c:2844
0xa4cb8b expand_gimple_stmt_1
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/cfgexpand.c:3877
0xa4cb8b expand_gimple_stmt
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/cfgexpand.c:4041
0xa528c9 expand_gimple_basic_block
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/cfgexpand.c:6083
0xa5479f execute
        /tmp/tmp.gHvB6MNy5h-gcc-builder/gcc/gcc/cfgexpand.c:6809
Please submit a full bug report,
with preprocessed source if appropriate.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

[Bug middle-end/101195] ICE: in tree_to_uhwi, at tree.c:6324

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101195

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Version|tree-ssa                    |12.0
           Keywords|                            |ice-on-valid-code
          Component|c                           |middle-end

--- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
Looks like there is a missing check on the argument types for this builtin.

[Bug middle-end/101195] ICE: in tree_to_uhwi, at tree.c:6324

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101195

Richard Biener <rguenth at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
           Keywords|                            |accepts-invalid
     Ever confirmed|0                           |1
             Status|UNCONFIRMED                 |NEW
   Last reconfirmed|                            |2021-06-25

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
DEF_GCC_BUILTIN        (BUILT_IN_EH_RETURN_DATA_REGNO, "eh_return_data_regno",
BT_FN_INT_INT, ATTR_LEAF_LIST)

so -42 is perfectly fine, but

2165        {
2166          error ("argument of %<__builtin_eh_return_regno%> must be
constant");
2167          return constm1_rtx;
2168        }
2169
2170      iwhich = tree_to_uhwi (which);

we then don't check the argument range before accessing it as unsigned.

[Bug middle-end/101195] ICE: in tree_to_uhwi, at tree.c:6324

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101195

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |141242068 at smail dot nju.edu.cn

--- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 111886 has been marked as a duplicate of this bug. ***

[Bug middle-end/101195] ICE: in tree_to_uhwi, at tree.c:6324

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101195

Andrew Pinski <pinskia at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |gabravier at gmail dot com

--- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> ---
*** Bug 113647 has been marked as a duplicate of this bug. ***

[Bug middle-end/101195] ICE: in tree_to_uhwi, at tree.c:6324

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101195

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|NEW                         |ASSIGNED
           Assignee|unassigned at gcc dot gnu.org      |jakub at gcc dot gnu.org

--- Comment #5 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 57249
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=57249&action=edit
gcc14-pr101195.patch

Initially I thought we should emit some error message, like that the argument
must be non-negative constant, but given the
  iwhich = EH_RETURN_DATA_REGNO (iwhich);
  if (iwhich == INVALID_REGNUM)
    return constm1_rtx;
a few lines later where it will on pretty much all architectures return
INVALID_REGNUM for all but 2-4 values and so silently expand to -1 at runtime
I think silently expanding the negative values to that as well is just fine.
There is no fundamental difference between -1, -42, 42 or 237 in this regard,
all of them most likely aren't eh regnos.

[Bug middle-end/101195] ICE: in tree_to_uhwi, at tree.c:6324

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101195

--- Comment #6 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Jakub Jelinek <jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:26c9b95b9f712ff1f813351b5d45371620085221

commit r14-8516-g26c9b95b9f712ff1f813351b5d45371620085221
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Tue Jan 30 09:57:21 2024 +0100

    except: Fix __builtin_eh_return_data_regno (-42) expansion [PR101195]

    The expansion of this builtin emits an error if the argument is not
    INTEGER_CST, otherwise uses tree_to_uhwi on the argument (which is declared
    int) and then uses EH_RETURN_DATA_REGNO macro which on most targets returns
    INVALID_REGNUM for all values but some small number (2 or 4); if it returns
    INVALID_REGNUM, we silently expand to -1.

    Now, I think the error for non-INTEGER_CST makes sense to catch when people
    unintentionally don't call it with a constant (but, users shouldn't really
    use this builtin anyway, it is for the unwinder only).  Initially I thought
    about emitting an error for the negative values as well on which
    tree_to_uhwi otherwise ICEs, but given that the function will silently
    expand to -1 for INT_MAX - 1 or INT_MAX - 3 other values, I think treating
    the negatives the same silently is fine too.

    2024-01-30  Jakub Jelinek  <jakub@redhat.com>

            PR middle-end/101195
            * except.cc (expand_builtin_eh_return_data_regno): If which doesn't
            fit into unsigned HOST_WIDE_INT, return constm1_rtx.

            * gcc.dg/pr101195.c: New test.

[Bug middle-end/101195] ICE: in tree_to_uhwi, at tree.c:6324

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101195

Jakub Jelinek <jakub at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
             Status|ASSIGNED                    |RESOLVED
         Resolution|---                         |FIXED
   Target Milestone|---                         |14.0

--- Comment #7 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed for GCC 14.  Not important to backport IMHO, this builtin is meant to be
used just in the unwinder, not in normal user code.