[Bug c++/101433] New: [modules] Bad File Data from simple function returning std::vector

[C.Damerius at gmx dot de via Gcc-bugs]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=101433

            Bug ID: 101433
           Summary: [modules] Bad File Data from simple function returning
                    std::vector
           Product: gcc
           Version: 11.1.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c++
          Assignee: unassigned at gcc dot gnu.org
          Reporter: C.Damerius at gmx dot de
  Target Milestone: ---

We have two files, A.cpp, and B.cpp with the contents:


A.cpp:
export module A;

import <vector>;

std::vector<int> ReturnVector() {
        std::vector<int> result;
        return result;
}


B.cpp:
export module B;

import A;


We execute the following commands:
g++-11 -std=c++20 -fmodules-ts -c -x c++-system-header vector
g++-11 -std=c++20 -fmodules-ts -c -o A.o A.cpp
g++-11 -std=c++20 -fmodules-ts -c -o B.o B.cpp

This produces the following output:
In module imported at B.cpp:3:1:
A: error: failed to read compiled module: Bad file data
A: note: compiled module file is ‘gcm.cache/A.gcm’
A: fatal error: returning to the gate for a mechanical issue
compilation terminated.

Version, System Type and Configuration/Build options as of "g+-11 -v":
Using built-in specs.
COLLECT_GCC=g++-11
COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/11/lto-wrapper
OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa
OFFLOAD_TARGET_DEFAULT=1
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
11.1.0-1ubuntu1~21.04' --with-bugurl=file:///usr/share/doc/gcc-11/README.Bugs
--enable-languages=c,ada,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr
--with-gcc-major-version-only --program-suffix=-11
--program-prefix=x86_64-linux-gnu- --enable-shared --enable-linker-build-id
--libexecdir=/usr/lib --without-included-gettext --enable-threads=posix
--libdir=/usr/lib --enable-nls --enable-bootstrap --enable-clocale=gnu
--enable-libstdcxx-debug --enable-libstdcxx-time=yes
--with-default-libstdcxx-abi=new --enable-gnu-unique-object
--disable-vtable-verify --enable-plugin --enable-default-pie --with-system-zlib
--enable-libphobos-checking=release --with-target-system-zlib=auto
--enable-objc-gc=auto --enable-multiarch --disable-werror --enable-cet
--with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32
--enable-multilib --with-tune=generic
--enable-offload-targets=nvptx-none=/build/gcc-11-RPS7jb/gcc-11-11.1.0/debian/tmp-nvptx/usr,amdgcn-amdhsa=/build/gcc-11-RPS7jb/gcc-11-11.1.0/debian/tmp-gcn/usr
--without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu
--host=x86_64-linux-gnu --target=x86_64-linux-gnu
--with-build-config=bootstrap-lto-lean --enable-link-serialization=2
Thread model: posix
Supported LTO compression algorithms: zlib zstd
gcc version 11.1.0 (Ubuntu 11.1.0-1ubuntu1~21.04)