https://gcc.gnu.org/bugzilla/show_bug.cgi?id=79814
Bug ID: 79814 Summary: pass-instances.def:36:14: error: ‘*<unknown>.gcc::pass_manager::pass_warn_unused_result _1’ is used uninitialized in this function Product: gcc Version: 7.0.1 Status: UNCONFIRMED Severity: normal Priority: P3 Component: bootstrap Assignee: unassigned at gcc dot gnu.org Reporter: rguenth at gcc dot gnu.org CC: dmalcolm at gcc dot gnu.org Target Milestone: --- With a slightly enhanced Wuninitialized I get a bootstrap failure: /tmp/obj/./prev-gcc/xg++ -B/tmp/obj/./prev-gcc/ -B/usr/local/x86_64-pc-linux-gnu/bin/ -nostdinc++ -B/tmp/obj/prev-x86_64-pc-linux-gnu/libstdc++-v3/src/.libs -B/tmp/obj/prev-x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs -I/tmp/obj/prev-x86_64-pc-linux-gnu/libstdc++-v3/include/x86_64-pc-linux-gnu -I/tmp/obj/prev-x86_64-pc-linux-gnu/libstdc++-v3/include -I/tmp/trunk/libstdc++-v3/libsupc++ -L/tmp/obj/prev-x86_64-pc-linux-gnu/libstdc++-v3/src/.libs -L/tmp/obj/prev-x86_64-pc-linux-gnu/libstdc++-v3/libsupc++/.libs -fno-PIE -c -g -O2 -DIN_GCC -fno-exceptions -fno-rtti -fasynchronous-unwind-tables -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wmissing-format-attribute -Woverloaded-virtual -pedantic -Wno-long-long -Wno-variadic-macros -Wno-overlength-strings -Werror -fno-common -DHAVE_CONFIG_H -I. -I. -I../../trunk/gcc -I../../trunk/gcc/. -I../../trunk/gcc/../include -I../../trunk/gcc/../libcpp/include -I../../trunk/gcc/../libdecnumber -I../../trunk/gcc/../libdecnumber/bid -I../libdecnumber -I../../trunk/gcc/../libbacktrace -o passes.o -MT passes.o -MMD -MP -MF ./.deps/passes.TPo ../../trunk/gcc/passes.c In file included from ../../trunk/gcc/passes.c:1595:0: ./pass-instances.def: In constructor ‘gcc::pass_manager::pass_manager(gcc::context*)’: ./pass-instances.def:36:14: error: ‘*<unknown>.gcc::pass_manager::pass_warn_unused_result_1’ is used uninitialized in this function [-Werror=uninitialized] NEXT_PASS (pass_warn_unused_result, 1); ^~~~~~~~~~~~~~~~~~~~~~~ it looks like pass_warn_unused_result_1 is used before initialization. CCing david who invented this C++ stuff I think.