[Bug debug/101266] New: ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[Bug debug/101266] New: ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[cnsun at uwaterloo dot ca]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

            Bug ID: 101266
           Summary: ICE with -g: in loc_list_from_tree_1, at
                    dwarf2out.c:19421
           Product: gcc
           Version: tree-ssa
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: debug
          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.uZ7IoZqhUx-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 20210630 (experimental) [master revision
:ddd6233e0:ed392e9db434898eccec81edd85323d21d555fe9] (GCC)

$ cat mutant.c
typedef U;
fn8(U (*)[(int){1}]) {}

$ gcc-trunk -w -g mutant.c
mutant.c:2:1: internal compiler error: in loc_list_from_tree_1, at
dwarf2out.c:19421
    2 | fn8(U (*)[(int){1}]) {}
      | ^~~
0x6b1ad0 loc_list_from_tree_1
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:19421
0xb224ad loc_list_from_tree_1
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:18927
0xb224ad loc_list_from_tree_1
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:18927
0xb22f18 loc_list_from_tree_1
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:19245
0xb25f1b loc_list_from_tree
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:19518
0xb319a5 add_scalar_info
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:21265
0xb32bce add_subscript_info
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:21507
0xb1d7b7 gen_array_type_die
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:22378
0xb1d7b7 gen_type_die_with_usage
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:26125
0xb1edd6 gen_type_die
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:26187
0xb3806e gen_decl_die
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:26826
0xb39296 dwarf2out_decl
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:27381
0xb39460 dwarf2out_type_decl
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:27099
0xb39460 dwarf2out_type_decl
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/dwarf2out.c:27094
0xe30b7a rest_of_decl_compilation(tree_node*, int, int)
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/passes.c:251
0x8f2ca7 finish_decl(tree_node*, unsigned int, tree_node*, tree_node*,
tree_node*)
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/c/c-decl.c:5606
0x8f692e grokdeclarator
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/c/c-decl.c:7171
0x8fa813 push_parm_decl(c_parm const*, tree_node**)
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/c/c-decl.c:5896
0x943079 c_parser_parms_list_declarator
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/c/c-parser.c:4291
0x9433ec c_parser_parms_declarator
        /tmp/tmp.uZ7IoZqhUx-gcc-builder/gcc/gcc/c/c-parser.c:4217
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 c/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
          Component|debug                       |c
     Ever confirmed|0                           |1
            Version|tree-ssa                    |12.0
   Last reconfirmed|                            |2021-06-30
             Status|UNCONFIRMED                 |NEW

--- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> ---
Confirmed.  We hit

#1  0x0000000000d898e5 in loc_list_from_tree_1 (loc=
    <compound_literal_expr 0x7ffff6688240>, want_address=0, context=0x0)
    at /home/rguenther/src/gcc2/gcc/dwarf2out.c:19421
19421           gcc_unreachable ();
(gdb) l
19416           }
19417
19418         /* Otherwise this is a generic code; we should just lists all of
19419            these explicitly.  We forgot one.  */
19420         if (flag_checking)
19421           gcc_unreachable ();
(gdb) p loc
$1 = <compound_literal_expr 0x7ffff6688240>
(gdb) p debug_generic_expr (loc)
<<< Unknown tree: compound_literal_expr
    int D.1943 = 1; >>>

and the original tree we ask for is

(long int) SAVE_EXPR <<<< Unknown tree: compound_literal_expr
    int D.1943 = 1; >>>> + -1

this looks like some missed DECL_EXPR / gimplification or a missed error.
clang complains:

> clang-9 t.c -S
t.c:1:9: warning: type specifier missing, defaults to 'int' [-Wimplicit-int]
typedef U;
~~~~~~~ ^
t.c:2:1: warning: type specifier missing, defaults to 'int' [-Wimplicit-int]
fn8(U (*)[(int){1}]) {}
^
t.c:2:9: error: parameter name omitted
fn8(U (*)[(int){1}]) {}
        ^
2 warnings and 1 error generated.

but adding a parameter name doesn't fix anything.  Note we call
dwarf2out_decl via

#14 0x0000000000d9f4f4 in dwarf2out_type_decl (
    decl=<type_decl 0x7ffff656b428>, local=0)
    at /home/rguenther/src/gcc2/gcc/dwarf2out.c:27099
#15 0x000000000120699d in rest_of_decl_compilation (
    decl=<type_decl 0x7ffff656b428>, top_level=1, at_end=0)
    at /home/rguenther/src/gcc2/gcc/passes.c:251
#16 0x0000000000a614a7 in finish_decl (decl=<type_decl 0x7ffff656b428>, 
    init_loc=246464, init=<tree 0x0>, origtype=<tree 0x0>, 
    asmspec_tree=<tree 0x0>) at /home/rguenther/src/gcc2/gcc/c/c-decl.c:5606
#17 0x0000000000a65c38 in grokdeclarator (declarator=0x385b320, 
    declspecs=0x385b170, decl_context=PARM, initialized=false, width=0x0, 
    decl_attrs=0x7fffffffd628, expr=0x7fffffffd648, 
    expr_const_operands=0x7fffffffd49f, deprecated_state=DEPRECATED_NORMAL)
    at /home/rguenther/src/gcc2/gcc/c/c-decl.c:7171

so this is before any gimplification happened.

[Bug c/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[marxin at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

Martin Liška <marxin at gcc dot gnu.org> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |marxin at gcc dot gnu.org,
                   |                            |rsandifo at gcc dot gnu.org

--- Comment #2 from Martin Liška <marxin at gcc dot gnu.org> ---
Started with r8-6733-gd74641bdd752306a.

[Bug debug/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

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

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

--- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
As dwarf2out.c is called on pre-gimplification GENERIC in that case, it should
handle GENERIC trees.

[Bug debug/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

--- Comment #4 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Created attachment 51089
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=51089&action=edit
gcc12-pr101266.patch

Untested fix.

[Bug debug/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

--- Comment #5 from CVS 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:b0ab968999c9af88d45acf552ca673ef3960306a

commit r12-1948-gb0ab968999c9af88d45acf552ca673ef3960306a
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Jul 1 09:45:02 2021 +0200

    dwarf2out: Handle COMPOUND_LITERAL_EXPR in loc_list_from_tree_1 [PR101266]

    In this case dwarf2out_decl is called from the FEs with GENERIC but not
    yet gimplified expressions in it.

    As loc_list_from_tree_1 has an exhaustive list of tree codes it wants to
    handle and for checking asserts no other codes makes it in, we should
    handle even GENERIC trees that shouldn't be valid in GIMPLE.

    The following patch handles COMPOUND_LITERAL_EXPR by hnadling it like the
    underlying VAR_DECL temporary.

    Verified the emitted DWARF is correct (but unoptimized, we emit
    DW_OP_lit1 DW_OP_lit1 DW_OP_minus for the upper bound).

    2021-07-01  Jakub Jelinek  <jakub@redhat.com>

            PR debug/101266
            * dwarf2out.c (loc_list_from_tree_1): Handle COMPOUND_LITERAL_EXPR.

            * gcc.dg/pr101266.c: New test.

[Bug debug/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

--- Comment #6 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed on the trunk so far.

[Bug debug/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

--- Comment #7 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-11 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:135680bdce4577208daf0507089ac932abdbf5f9

commit r11-8769-g135680bdce4577208daf0507089ac932abdbf5f9
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Jul 1 09:45:02 2021 +0200

    dwarf2out: Handle COMPOUND_LITERAL_EXPR in loc_list_from_tree_1 [PR101266]

    In this case dwarf2out_decl is called from the FEs with GENERIC but not
    yet gimplified expressions in it.

    As loc_list_from_tree_1 has an exhaustive list of tree codes it wants to
    handle and for checking asserts no other codes makes it in, we should
    handle even GENERIC trees that shouldn't be valid in GIMPLE.

    The following patch handles COMPOUND_LITERAL_EXPR by hnadling it like the
    underlying VAR_DECL temporary.

    Verified the emitted DWARF is correct (but unoptimized, we emit
    DW_OP_lit1 DW_OP_lit1 DW_OP_minus for the upper bound).

    2021-07-01  Jakub Jelinek  <jakub@redhat.com>

            PR debug/101266
            * dwarf2out.c (loc_list_from_tree_1): Handle COMPOUND_LITERAL_EXPR.

            * gcc.dg/pr101266.c: New test.

    (cherry picked from commit b0ab968999c9af88d45acf552ca673ef3960306a)

[Bug debug/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-10 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:cd1076871987740312a040fba9ba4e7c047bdedf

commit r10-10629-gcd1076871987740312a040fba9ba4e7c047bdedf
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Jul 1 09:45:02 2021 +0200

    dwarf2out: Handle COMPOUND_LITERAL_EXPR in loc_list_from_tree_1 [PR101266]

    In this case dwarf2out_decl is called from the FEs with GENERIC but not
    yet gimplified expressions in it.

    As loc_list_from_tree_1 has an exhaustive list of tree codes it wants to
    handle and for checking asserts no other codes makes it in, we should
    handle even GENERIC trees that shouldn't be valid in GIMPLE.

    The following patch handles COMPOUND_LITERAL_EXPR by hnadling it like the
    underlying VAR_DECL temporary.

    Verified the emitted DWARF is correct (but unoptimized, we emit
    DW_OP_lit1 DW_OP_lit1 DW_OP_minus for the upper bound).

    2021-07-01  Jakub Jelinek  <jakub@redhat.com>

            PR debug/101266
            * dwarf2out.c (loc_list_from_tree_1): Handle COMPOUND_LITERAL_EXPR.

            * gcc.dg/pr101266.c: New test.

    (cherry picked from commit b0ab968999c9af88d45acf552ca673ef3960306a)

[Bug debug/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

--- Comment #9 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The releases/gcc-9 branch has been updated by Jakub Jelinek
<jakub@gcc.gnu.org>:

https://gcc.gnu.org/g:1df7b899cd854fdda052fb6218c2ff9e8898df42

commit r9-10086-g1df7b899cd854fdda052fb6218c2ff9e8898df42
Author: Jakub Jelinek <jakub@redhat.com>
Date:   Thu Jul 1 09:45:02 2021 +0200

    dwarf2out: Handle COMPOUND_LITERAL_EXPR in loc_list_from_tree_1 [PR101266]

    In this case dwarf2out_decl is called from the FEs with GENERIC but not
    yet gimplified expressions in it.

    As loc_list_from_tree_1 has an exhaustive list of tree codes it wants to
    handle and for checking asserts no other codes makes it in, we should
    handle even GENERIC trees that shouldn't be valid in GIMPLE.

    The following patch handles COMPOUND_LITERAL_EXPR by hnadling it like the
    underlying VAR_DECL temporary.

    Verified the emitted DWARF is correct (but unoptimized, we emit
    DW_OP_lit1 DW_OP_lit1 DW_OP_minus for the upper bound).

    2021-07-01  Jakub Jelinek  <jakub@redhat.com>

            PR debug/101266
            * dwarf2out.c (loc_list_from_tree_1): Handle COMPOUND_LITERAL_EXPR.

            * gcc.dg/pr101266.c: New test.

    (cherry picked from commit b0ab968999c9af88d45acf552ca673ef3960306a)

[Bug debug/101266] ICE with -g: in loc_list_from_tree_1, at dwarf2out.c:19421

[jakub at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101266

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

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

--- Comment #10 from Jakub Jelinek <jakub at gcc dot gnu.org> ---
Fixed.