https://gcc.gnu.org/bugzilla/show_bug.cgi?id=80476
Bug ID: 80476 Summary: GCC 7 can't be compiled with bootstrap-O3 Product: gcc Version: 7.1.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: bootstrap Assignee: unassigned at gcc dot gnu.org Reporter: mikulas at artax dot karlin.mff.cuni.cz Target Milestone: --- Host: x86_64-pc-linux-gnu Target: x86_64-pc-linux-gnu Build: x86_64-pc-linux-gnu When compiling GCC 7 with -O3 (using the configure flag --with-build-config=bootstrap-O3), it fails due to uninitialized variables. This is the script to compile GCC: #!/bin/sh set -e MAKEFLAGS=-j12 export MAKEFLAGS ../gcc-7-20170416/configure \ --prefix=/usr/local/gcc/ \ --enable-lto \ --with-system-zlib \ --enable-languages=c,c++ \ --enable-multilib \ --with-multilib-list=m32,m64,mx32 \ --with-build-config=bootstrap-O3 \ && nice -n 20 make bootstrap This is the result: In file included from ../../gcc-7-20170416/gcc/target.h:53:0, from ../../gcc-7-20170416/gcc/ira-color.c:25: ../../gcc-7-20170416/gcc/hard-reg-set.h: In function 'bool ira_reassign_pseudos(int*, int, HARD_REG_ELT_TYPE*, HARD_REG_ELT_TYPE (*)[2], HARD_REG_ELT_TYPE (*)[2], bitmap)': ../../gcc-7-20170416/gcc/hard-reg-set.h:174:18: error: '*((void*)& saved +24)' may be used uninitialized in this function [-Werror=maybe-uninitialized] scan_tp_[1] = scan_fp_[1]; } while (0) ^ ../../gcc-7-20170416/gcc/ira-color.c:4327:16: note: '*((void*)& saved +24)' was declared here HARD_REG_SET saved[2]; ^~~~~ In file included from ../../gcc-7-20170416/gcc/target.h:53:0, from ../../gcc-7-20170416/gcc/ira-color.c:25: ../../gcc-7-20170416/gcc/hard-reg-set.h:173:18: error: '*((void*)& saved +16)' may be used uninitialized in this function [-Werror=maybe-uninitialized] scan_tp_[0] = scan_fp_[0]; \ ^ ../../gcc-7-20170416/gcc/ira-color.c:4327:16: note: '*((void*)& saved +16)' was declared here HARD_REG_SET saved[2]; ^~~~~ In file included from ../../gcc-7-20170416/gcc/target.h:53:0, from ../../gcc-7-20170416/gcc/ira-color.c:25: ../../gcc-7-20170416/gcc/hard-reg-set.h:174:18: error: '*((void*)& saved +8)' may be used uninitialized in this function [-Werror=maybe-uninitialized] scan_tp_[1] = scan_fp_[1]; } while (0) ^ ../../gcc-7-20170416/gcc/ira-color.c:4327:16: note: '*((void*)& saved +8)' was declared here HARD_REG_SET saved[2]; ^~~~~ In file included from ../../gcc-7-20170416/gcc/target.h:53:0, from ../../gcc-7-20170416/gcc/ira-color.c:25: ../../gcc-7-20170416/gcc/hard-reg-set.h:173:18: error: 'saved' may be used uninitialized in this function [-Werror=maybe-uninitialized] scan_tp_[0] = scan_fp_[0]; \ ^ ../../gcc-7-20170416/gcc/ira-color.c:4327:16: note: 'saved' was declared here HARD_REG_SET saved[2]; ^~~~~ cc1plus: all warnings being treated as errors Makefile:1106: návod pro cíl ,,ira-color.o" selhal make[3]: *** [ira-color.o] Chyba 1 make[3]: *** Čeká se na nedokončené úlohy... rm fsf-funding.pod gcov.pod gpl.pod cpp.pod gfdl.pod gcc.pod gcov-dump.pod gcov-tool.pod make[3]: Opouští se adresář ,,/usr/src/gcc-7.1.0-test/gcc" Makefile:4588: návod pro cíl ,,all-stage2-gcc" selhal make[2]: *** [all-stage2-gcc] Chyba 2 make[2]: Opouští se adresář ,,/usr/src/gcc-7.1.0-test" Makefile:22065: návod pro cíl ,,stage2-bubble" selhal make[1]: *** [stage2-bubble] Chyba 2 make[1]: Opouští se adresář ,,/usr/src/gcc-7.1.0-test" Makefile:22268: návod pro cíl ,,bootstrap" selhal make: *** [bootstrap] Chyba 2