[Bug go/107581] New: ICE on sparc-leon-uclibc during go build

[Bug go/107581] New: ICE on sparc-leon-uclibc during go build

[dkm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

            Bug ID: 107581
           Summary: ICE on sparc-leon-uclibc during go build
           Product: gcc
           Version: unknown
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: go
          Assignee: ian at airs dot com
          Reporter: dkm at gcc dot gnu.org
  Target Milestone: ---

While building a cross compiler for sparc-leon with Go enabled, I get the
following ICE:

/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/build/build-cc-gcc-final/./gcc/gccgo
-B/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/build/build-cc-gcc-final/./gcc/
-B/path/crosstool-scratch/sparc-leon-linux-uclibc/sparc-leon-linux-uclibc/bin/
-B/path/crosstool-scratch/sparc-leon-linux-uclibc/sparc-leon-linux-uclibc/lib/
-isystem
/path/crosstool-scratch/sparc-leon-linux-uclibc/sparc-leon-linux-uclibc/include
-isystem
/path/crosstool-scratch/sparc-leon-linux-uclibc/sparc-leon-linux-uclibc/sys-include
-O2 -g -I . -c -fgo-pkgpath=runtime/internal/atomic -fgo-compiling-runtime
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/libgo/go/runtime/internal/atomic/doc.go
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/libgo/go/runtime/internal/atomic/gccgo.go
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/libgo/go/runtime/internal/atomic/stubs.go
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/libgo/go/runtime/internal/atomic/types.go
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/libgo/go/runtime/internal/atomic/unaligned.go
 -fPIC -o runtime/internal/.libs/atomic.o -freport-bug -save-temps

during RTL pass: expand
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/libgo/go/runtime/internal/atomic/types.go:
In function 'runtime/internal/atomic.Int32.Add':
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/libgo/go/runtime/internal/atomic/types.go:47:16:
internal compiler error: Segmentation fault
   47 |         return Xaddint32(&i.value, delta)
      |                ^
0xc01d6f crash_signal
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/toplev.cc:314
0x7f7eff3daf8f ???
        ./signal/../sysdeps/unix/sysv/linux/x86_64/libc_sigaction.c:0
0xeea114 get_callee_fndecl(tree_node const*)
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/tree.cc:8459
0x72f8f0 expand_call(tree_node*, rtx_def*, int)
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/calls.cc:2740
0x717412 expand_builtin_atomic_fetch_op
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/builtins.cc:6497
0x7234c2 expand_builtin(tree_node*, rtx_def*, rtx_def*, machine_mode, int)
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/builtins.cc:8343
0x864639 expand_expr_real_1(tree_node*, rtx_def*, machine_mode,
expand_modifier, rtx_def**, bool)
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/expr.cc:11865
0x86e065 store_expr(tree_node*, rtx_def*, int, bool, bool)
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/expr.cc:6330
0x870720 expand_assignment(tree_node*, tree_node*, bool)
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/expr.cc:6051
0x74301c expand_call_stmt
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/cfgexpand.cc:2829
0x74301c expand_gimple_stmt_1
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/cfgexpand.cc:3880
0x74301c expand_gimple_stmt
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/cfgexpand.cc:4044
0x7489ae expand_gimple_basic_block
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/cfgexpand.cc:6096
0x74a55e execute
       
/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/gcc/cfgexpand.cc:6822
Please submit a full bug report, with preprocessed source.
Please include the complete backtrace with any bug report.
See <https://gcc.gnu.org/bugs/> for instructions.

I can provide more info if needed, or rebuild with a debug build.

The ICE has been first observed on 12.2.0 tgz and reproduced on today's master
(bbcb84bb)

The build has been configured with: 
 CC_FOR_BUILD='x86_64-build_pc-linux-gnu-gcc' CFLAGS='-O2 -g -pipe
-I/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools/include  '
CFLAGS_FOR_BUILD='-O2 -g -pipe
-I/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools/include  '
CXXFLAGS='-O2 -g -pipe
-I/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools/include   '
CXXFLAGS_FOR_BUILD='-O2 -g -pipe
-I/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools/include   '
LDFLAGS='-L/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools/lib
 ' CFLAGS_FOR_TARGET='-g -O2 ' CXXFLAGS_FOR_TARGET='-g -O2 '
LDFLAGS_FOR_TARGET='' '/usr/bin/bash'
'/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/src/gcc/configure'
'--build=x86_64-build_pc-linux-gnu' '--host=x86_64-build_pc-linux-gnu'
'--target=sparc-leon-linux-uclibc'
'--prefix=/path/crosstool-scratch/sparc-leon-linux-uclibc'
'--exec_prefix=/path/crosstool-scratch/sparc-leon-linux-uclibc'
'--with-sysroot=/path/crosstool-scratch/sparc-leon-linux-uclibc/sparc-leon-linux-uclibc/sysroot'
'--enable-languages=c,c++,fortran,d,objc,go' '--with-cpu=leon'
'--with-tune=leon' '--with-float=soft' '--with-pkgversion=crosstool-NG
1.25.0.95_7622b49' '--enable-__cxa_atexit' '--disable-libmudflap'
'--disable-libgomp' '--disable-libssp' '--disable-libquadmath'
'--disable-libquadmath-support' '--disable-libsanitizer' '--disable-libmpx'
'--with-gmp=/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools'
'--with-mpfr=/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools'
'--with-mpc=/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools'
'--with-isl=/path/git/crosstool-ng/.build/sparc-leon-linux-uclibc/buildtools'
'--enable-lto' '--enable-threads=posix' '--enable-target-optspace'
'--disable-plugin' '--disable-nls' '--disable-multilib'
'--with-local-prefix=/path/crosstool-scratch/sparc-leon-linux-uclibc/sparc-leon-linux-uclibc/sysroot'
'--enable-long-long' '--disable-libitm'

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

Ian Lance Taylor <ian at airs dot com> changed:

           What    |Removed                     |Added
----------------------------------------------------------------------------
                 CC|                            |ian at airs dot com

--- Comment #1 from Ian Lance Taylor <ian at airs dot com> ---
This crash appears to be fairly deep in the middle-end.  Nothing has changed
recently in the Go frontend.  Has this crash just started appearing, or is this
the first time you are trying this?  If it is a relatively new crash then I
think it must be related to some middle-end change.  Thanks.

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[rguenth at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
            Version|unknown                     |12.2.0

--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
I assume that reproducing with trunk is with checking enabled?  It would be
nice if you can do a debugging session on the crashing go1 invocation and
inspect the GIMPLE that's being expanded.  From the backtrace it looks like
it's some
BUILT_IN_ATOMIC_FETCH_* and expand_builtin_atomic_fetch_op does

  /* Change the call to the specified function.  */
  fndecl = get_callee_fndecl (exp);
  addr = CALL_EXPR_FN (exp);
  STRIP_NOPS (addr);

  gcc_assert (TREE_OPERAND (addr, 0) == fndecl);
  TREE_OPERAND (addr, 0) = builtin_decl_explicit (ext_call);

and this builtin_decl_explicit ends up NULL so we later crash.  Adding an
assert that this isn't so after the above would confirm this.  We compute
ext_call (lib) as

    case BUILT_IN_ATOMIC_ADD_FETCH_1:
    case BUILT_IN_ATOMIC_ADD_FETCH_2:
    case BUILT_IN_ATOMIC_ADD_FETCH_4:
    case BUILT_IN_ATOMIC_ADD_FETCH_8:
    case BUILT_IN_ATOMIC_ADD_FETCH_16:
      {
        enum built_in_function lib;
        mode = get_builtin_sync_mode (fcode - BUILT_IN_ATOMIC_ADD_FETCH_1);
        lib = (enum built_in_function)((int)BUILT_IN_ATOMIC_FETCH_ADD_1 +
                                       (fcode - BUILT_IN_ATOMIC_ADD_FETCH_1));
        target = expand_builtin_atomic_fetch_op (mode, exp, target, PLUS, true,
                                                 ignore, lib);

as said, tracing exactly what fcode and lib is here would be useful. 
Eventually this is a frontend issue, not properly initializing the builtins.

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[dkm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

--- Comment #3 from Marc Poulhiès <dkm at gcc dot gnu.org> ---
(In reply to Ian Lance Taylor from comment #1)
> This crash appears to be fairly deep in the middle-end.  Nothing has changed
> recently in the Go frontend.  Has this crash just started appearing, or is
> this the first time you are trying this?  If it is a relatively new crash
> then I think it must be related to some middle-end change.  Thanks.

This is a first try. I was trying 12.2.0 (ICE) then checked with trunk to see
if it was still crashing.


(In reply to Richard Biener from comment #2)
> I assume that reproducing with trunk is with checking enabled?  It would be
> nice if you can do a debugging session on the crashing go1 invocation and
> inspect the GIMPLE that's being expanded.  From the backtrace it looks like
> it's some

I don't think the build has any checking enabled but I have to check (that's
from a crosstool-ng build, so I doubt they are enabling checks).

I'll do a debug build and add the more detailed log here.

Thanks

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[dkm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

--- Comment #4 from Marc Poulhiès <dkm at gcc dot gnu.org> ---
You're correct, builtin_decl_explicit returns NULL.

As for the lib and fcode:

8186          {
8187            enum built_in_function lib;
8188            mode = get_builtin_sync_mode (fcode -
BUILT_IN_ATOMIC_ADD_FETCH_1);
8189            lib = (enum built_in_function)((int)BUILT_IN_ATOMIC_FETCH_ADD_1
+ 
8190                                           (fcode -
BUILT_IN_ATOMIC_ADD_FETCH_1));
> 8191          target = expand_builtin_atomic_fetch_op (mode, exp, target, PLUS, true,
8192                                                     ignore, lib);
8193            if (target)
8194              return target;
8195            break;
(rr) p lib
$8 = BUILT_IN_ATOMIC_FETCH_ADD_4
(rr) p fcode
$9 = BUILT_IN_ATOMIC_ADD_FETCH_4

Let me know if I can do anything else to help.

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[dkm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

--- Comment #5 from Marc Poulhiès <dkm at gcc dot gnu.org> ---
Created attachment 53862
  --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=53862&action=edit
naive patch

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[dkm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

--- Comment #6 from Marc Poulhiès <dkm at gcc dot gnu.org> ---
IIUC, the builtin for ADD_FETCH_4 is correctly defined (there's an entry with a
corresponding decl), but there's no builtin for FETCH_ADD_4.

When looking in go-gcc.cc, I see that only the ADD_FETCH is defined, and not
the FETCH_ADD. I'm testing a simple patch. It fixes the segfault but the libgo
still won't build because of missing symbols (probably an issue in uclibc? Not
sure it's worth the effort...).

I'm now regtesting the patch on x86_64.

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

--- Comment #7 from Ian Lance Taylor <ian at airs dot com> ---
Interesting, thanks.  The Go frontend will never emit a call to
__atomic_fetch_add_4.  I didn't realize that the middle end could convert
__atomic_add_fetch_4 into that.  Your patch looks right.  I'll commit after
testing.

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[cvs-commit at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

--- Comment #8 from CVS Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Ian Lance Taylor <ian@gcc.gnu.org>:

https://gcc.gnu.org/g:219f82070903625d6bd8865b5ecb5f944bcee871

commit r13-3868-g219f82070903625d6bd8865b5ecb5f944bcee871
Author: Ian Lance Taylor <iant@golang.org>
Date:   Wed Nov 9 16:05:08 2022 -0800

    go: don't crash if __atomic_fetch_add functions are used

    The Go frontend only generates __atomic_add_fetch, but in some cases
    thost calls become __atomic_fetch_add.

    Patch originally by Marc Poulhiès.

            PR target/107581
            * go-gcc.cc (Gcc_backend::Gcc_backend): Define
            __atomic_fetch_add_{4,8}.

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[ian at airs dot com]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

Ian Lance Taylor <ian at airs dot com> changed:

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

--- Comment #9 from Ian Lance Taylor <ian at airs dot com> ---
Should be fixed on mainline.  Thanks.

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[dkm at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

--- Comment #10 from Marc Poulhiès <dkm at gcc dot gnu.org> ---
Thanks for applying the fix Ian!

[Bug target/107581] ICE on sparc-leon-uclibc during go build

[pinskia at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107581

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

           What    |Removed                     |Added
----------------------------------------------------------------------------
   Target Milestone|---                         |13.0