MinGW-GCC internal compiler error on Windows x86_32 with LTO enabled

[akien-mga]

Tested versions

• Reproducible in 4.3.beta (a4f2ea9)
• Not reproducible in 4.3.dev6 (64520fe)
• Bisected to [Core] Add scalar versions of Vector* min/max/clamp/snap(ped) #89114

System information

Fedora 39, MinGW-GCC 13.2.1

Issue description

I don't know why yet, but MinGW-GCC LTO builds failed for Windows x86_32 shortly after 4.3-dev6. I bisected it to #89114.

When building with scons platform=windows arch=x86_32 target=editor production=yes, I ran into one of several possible linking issues:

lto1: error: two or more sections for .gnu.lto__ZZL33_register_variant_builtin_methodsvEN44Method_PackedByteArray_get_string_from_wchar17get_argument_typeEi.lto_priv.0.24543200.12b4f1e18c89c353
(null):0: confused by earlier errors, bailing out

lto1: error: two or more sections for .gnu.lto__ZZL33_register_variant_builtin_methodsvEN27Method_PackedByteArray_sort17get_argument_typeEi.lto_priv.0.24488113.7355bbf912c4778c
(null):0: confused by earlier errors, bailing out

Or outright:

lto1: internal compiler error: cannot read 'LTO_section_decls' from /tmp/cc5pGqEL.ltrans116.o

Somehow #89114 is triggering a bug in GCC LTO.

Steps to reproduce

• Setup MinGW-GCC (used Fedora 39 packages, GCC version 13.2.1 and MinGW headers 11.0.0)
• Compiling with scons platform=windows arch=x86_32 target=editor production=yes

Minimal reproduction project (MRP)

n/a

[akien-mga]

I found this while building 4.3-beta1 and couldn't find a quick fix, so for that build I'm going to release Windows 32-bit builds without LTO. But we should find a workaround for beta2 ideally.

[akien-mga]

I still have this error in the current master branch in a fedora:39 container:

lto1: error: two or more sections for .gnu.lto__ZZL39_register_variant_builtin_methods_arrayvEN16Method_Array_map17get_argument_typeEi.lto_priv.0.24592882.34357455644a6950
(null):0: confused by earlier errors, bailing out

On the other hand it's not reproducible in a fedora:40 container, so it's related to the mingw/gcc/binutils versions.

[akien-mga]

So I didn't do a full investigation but the quick conclusion is that the MinGW/GCC/binutils combo in Fedora 39 has a bug. The easy solution is to update our containers to Fedora 40, which has newer versions of those packages and fixes that bug.

So I'm doing this for 4.3-beta2.

[limbonaut]

I encountered the same issue using Ubuntu 24.04 GitHub runner and 4.3-stable. Just FYI, no need to reopen.

lto1: error: two or more sections for .gnu.lto__ZZL39_register_variant_builtin_methods_arrayvEN27Method_PackedByteArray_fill17get_argument_typeEi.lto_priv.0.34929690.16dd58478e33f9a6
(null):0: confused by earlier errors, bailing out