https://gcc.gnu.org/bugzilla/show_bug.cgi?id=94288
Bug ID: 94288 Summary: co_await in while loop crashes g++ Product: gcc Version: 10.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: chbugzilla at outlook dot com Target Milestone: --- Created attachment 48095 --> https://gcc.gnu.org/bugzilla/attachment.cgi?id=48095&action=edit Pre-processed sample code I am using a recent development build of g++-10 to test some coroutine code that I am able to run successfully using MSVC but that leads to a compiler crash with g++. I attached a small sample to reproduce the issue. I am not sure what's the root cause but I am able to workaround the problem by pulling the co_await out of the while loop condition. Replacing std::vector<int> with e.g. int and testing for zero in the while loop also crashes the compiler, albeit with a different error. Build command: -------------- g++-10 -fcoroutines -std=c++20 -pthread sample.cpp Output of build: ---------------- sample.cpp: In function ‘void _Z3barv.actor(bar()::_Z3barv.frame*)’: sample.cpp:72:5: internal compiler error: in fold_convert_loc, at fold-const.c:2435 72 | while ((co_await foo()).empty()) | ^~~~~ 0x5d60f2 fold_convert_loc(unsigned int, tree_node*, tree_node*) ../../src/gcc/fold-const.c:2435 0x9d6a1a gimplify_cond_expr ../../src/gcc/gimplify.c:4149 0x9ce9e2 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ../../src/gcc/gimplify.c:13559 0x9cf0fd gimplify_stmt(tree_node**, gimple**) ../../src/gcc/gimplify.c:6823 0x9cf0fd gimplify_statement_list ../../src/gcc/gimplify.c:1869 0x9cf0fd gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ../../src/gcc/gimplify.c:14046 0x9d1f59 gimplify_stmt(tree_node**, gimple**) ../../src/gcc/gimplify.c:6823 0x9d1f59 gimplify_and_add(tree_node*, gimple**) ../../src/gcc/gimplify.c:486 0x9d1f59 gimplify_loop_expr ../../src/gcc/gimplify.c:1843 0x9cf216 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ../../src/gcc/gimplify.c:13807 0x9cf0fd gimplify_stmt(tree_node**, gimple**) ../../src/gcc/gimplify.c:6823 0x9cf0fd gimplify_statement_list ../../src/gcc/gimplify.c:1869 0x9cf0fd gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ../../src/gcc/gimplify.c:14046 0x9cf0fd gimplify_stmt(tree_node**, gimple**) ../../src/gcc/gimplify.c:6823 0x9cf0fd gimplify_statement_list ../../src/gcc/gimplify.c:1869 0x9cf0fd gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ../../src/gcc/gimplify.c:14046 0x9ce267 gimplify_stmt(tree_node**, gimple**) ../../src/gcc/gimplify.c:6823 0x9ce267 gimplify_and_add(tree_node*, gimple**) ../../src/gcc/gimplify.c:486 0x9ce267 gimplify_expr(tree_node**, gimple**, gimple**, bool (*)(tree_node*), int) ../../src/gcc/gimplify.c:13953 0x9cf0fd gimplify_stmt(tree_node**, gimple**) ../../src/gcc/gimplify.c:6823 Output of g++-10 -v: -------------------- Using built-in specs. COLLECT_GCC=g++-10 COLLECT_LTO_WRAPPER=/usr/lib/gcc/x86_64-linux-gnu/10/lto-wrapper OFFLOAD_TARGET_NAMES=nvptx-none:amdgcn-amdhsa:hsa OFFLOAD_TARGET_DEFAULT=1 Target: x86_64-linux-gnu Configured with: ../src/configure -v --with-pkgversion='Ubuntu 10-20200321-1ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-10/README.Bugs --enable-languages=c,c++,go,brig,d,fortran,objc,obj-c++,m2 --prefix=/usr --with-gcc-major-version-only --program-suffix=-10 --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-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 --with-target-system-zlib=auto --enable-objc-gc=auto --enable-multiarch --disable-werror --with-arch-32=i686 --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --with-tune=generic --enable-offload-targets=nvptx-none,amdgcn-amdhsa,hsa --without-cuda-driver --enable-checking=release --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu Thread model: posix Supported LTO compression algorithms: zlib zstd gcc version 10.0.1 20200321 (experimental) [master revision 15711e837b2:ab6586cb024:497498c878d48754318e486428e2aa30854020b9] (Ubuntu 10-20200321-1ubuntu1)