https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102119
Bug ID: 102119 Summary: ICE when accessing an uninitialised variable in a dynamic array of unions in a constexpr context. Product: gcc Version: 11.2.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c++ Assignee: unassigned at gcc dot gnu.org Reporter: gcc_report_187375 at mailfence dot com Target Milestone: --- Source code: ====================================== union U { int value; constexpr U() noexcept { } constexpr ~U() noexcept { } }; constexpr int z() { U* array = new U[5]; int result = array[3].value; delete[] array; return result; } constexpr int zz = z(); int main() { } ====================================== Compilation output (compiled with: gcc -v -save-temps -std=c++20): ====================================== Using built-in specs. COLLECT_GCC=/opt/compiler-explorer/gcc-11.2.0/bin/g++ Target: x86_64-linux-gnu Configured with: ../gcc-11.2.0/configure --prefix=/opt/compiler-explorer/gcc-build/staging --build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu --disable-bootstrap --enable-multiarch --with-abi=m64 --with-multilib-list=m32,m64,mx32 --enable-multilib --enable-clocale=gnu --enable-languages=c,c++,fortran,ada,go,d --enable-ld=yes --enable-gold=yes --enable-libstdcxx-debug --enable-libstdcxx-time=yes --enable-linker-build-id --enable-lto --enable-plugins --enable-threads=posix --with-pkgversion=Compiler-Explorer-Build-gcc--binutils-2.36.1 Thread model: posix Supported LTO compression algorithms: zlib gcc version 11.2.0 (Compiler-Explorer-Build-gcc--binutils-2.36.1) COLLECT_GCC_OPTIONS='-fdiagnostics-color=always' '-g' '-o' '/app/output.s' '-masm=intel' '-S' '-v' '-save-temps' '-std=c++20' '-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' '/app/' /opt/compiler-explorer/gcc-11.2.0/bin/../libexec/gcc/x86_64-linux-gnu/11.2.0/cc1plus -E -quiet -v -imultiarch x86_64-linux-gnu -iprefix /opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/x86_64-linux-gnu/11.2.0/ -D_GNU_SOURCE <source> -masm=intel -mtune=generic -march=x86-64 -std=c++20 -fdiagnostics-color=always -g -fworking-directory -fpch-preprocess -o /app/output.ii ignoring nonexistent directory "/opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/x86_64-linux-gnu/11.2.0/../../../../x86_64-linux-gnu/include" ignoring duplicate directory "/opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.2.0/../../../../include/c++/11.2.0" ignoring duplicate directory "/opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.2.0/../../../../include/c++/11.2.0/x86_64-linux-gnu" ignoring duplicate directory "/opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.2.0/../../../../include/c++/11.2.0/backward" ignoring duplicate directory "/opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.2.0/include" ignoring nonexistent directory "/usr/local/include/x86_64-linux-gnu" ignoring duplicate directory "/opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.2.0/include-fixed" ignoring nonexistent directory "/opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/../../lib/gcc/x86_64-linux-gnu/11.2.0/../../../../x86_64-linux-gnu/include" #include "..." search starts here: #include <...> search starts here: /opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/x86_64-linux-gnu/11.2.0/../../../../include/c++/11.2.0 /opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/x86_64-linux-gnu/11.2.0/../../../../include/c++/11.2.0/x86_64-linux-gnu /opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/x86_64-linux-gnu/11.2.0/../../../../include/c++/11.2.0/backward /opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/x86_64-linux-gnu/11.2.0/include /opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/x86_64-linux-gnu/11.2.0/include-fixed /usr/local/include /opt/compiler-explorer/gcc-11.2.0/bin/../lib/gcc/../../include /usr/include/x86_64-linux-gnu /usr/include End of search list. COLLECT_GCC_OPTIONS='-fdiagnostics-color=always' '-g' '-o' '/app/output.s' '-masm=intel' '-S' '-v' '-save-temps' '-std=c++20' '-shared-libgcc' '-mtune=generic' '-march=x86-64' '-dumpdir' '/app/' /opt/compiler-explorer/gcc-11.2.0/bin/../libexec/gcc/x86_64-linux-gnu/11.2.0/cc1plus -fpreprocessed /app/output.ii -quiet -dumpdir /app/ -dumpbase output.cpp -dumpbase-ext .cpp -masm=intel -mtune=generic -march=x86-64 -g -std=c++20 -version -fdiagnostics-color=always -o /app/output.s GNU C++20 (Compiler-Explorer-Build-gcc--binutils-2.36.1) version 11.2.0 (x86_64-linux-gnu) compiled by GNU C version 7.5.0, GMP version 6.1.0, MPFR version 3.1.6, MPC version 1.0.3, isl version isl-0.18-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 GNU C++20 (Compiler-Explorer-Build-gcc--binutils-2.36.1) version 11.2.0 (x86_64-linux-gnu) compiled by GNU C version 7.5.0, GMP version 6.1.0, MPFR version 3.1.6, MPC version 1.0.3, isl version isl-0.18-GMP GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072 Compiler executable checksum: 04bf73fb6238a66ccbfea1df0fdb5d66 ' <source>:14: confused by earlier errors, bailing out ======================================