https://gcc.gnu.org/bugzilla/show_bug.cgi?id=107197
Bug ID: 107197 Summary: valgrind error in function same_line_p during build Product: gcc Version: 12.0 Status: UNCONFIRMED Severity: normal Priority: P3 Component: c Assignee: unassigned at gcc dot gnu.org Reporter: dcb314 at hotmail dot com Target Milestone: --- I've just had a go at building gcc trunk with -O3 under valgrind and I got the following error: /home/dcb/gcc/working/./gcc/xgcc -B/home/dcb/gcc/working/./gcc/ -B/home/dcb/gcc/results.20221009.valgrind/x86_64-pc-linux-gnu/bin/ -B/home/dcb/gcc/results.20221009.valgrind/x86_64-pc-linux-gnu/lib/ -isystem /home/dcb/gcc/results.20221009.valgrind/x86_64-pc-linux-gnu/include -isystem /home/dcb/gcc/results.20221009.valgrind/x86_64-pc-linux-gnu/sys-include -g -O3 -O2 -g -O3 -DIN_GCC -W -Wall -Wno-narrowing -Wwrite-strings -Wcast-qual -Wstrict-prototypes -Wmissing-prototypes -Wold-style-definition -isystem ./include -I. -I. -I../.././gcc -I../../../trunk.git/libgcc -I../../../trunk.git/libgcc/. -I../../../trunk.git/libgcc/../gcc -I../../../trunk.git/libgcc/../include -I../../../trunk.git/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -g0 -finhibit-size-directive -fno-inline -fno-exceptions -fno-zero-initialized-in-bss -fno-toplevel-reorder -fno-tree-vectorize -fbuilding-libgcc -fno-stack-protector -I. -I. -I../.././gcc -I../../../trunk.git/libgcc -I../../../trunk.git/libgcc/. -I../../../trunk.git/libgcc/../gcc -I../../../trunk.git/libgcc/../include -I../../../trunk.git/libgcc/config/libbid -DENABLE_DECIMAL_BID_FORMAT -o crtendS.o -MT crtendS.o -MD -MP -MF crtendS.dep -fno-omit-frame-pointer -fno-asynchronous-unwind-tables -fcf-protection -mshstk -fpic -c ../../../trunk.git/libgcc/crtstuff.c -DCRT_END -DCRTSTUFFS_O ==107792== Conditional jump or move depends on uninitialised value(s) ==107792== at 0xD5004B: same_line_p (tree-cfg.cc:1160) ==107792== by 0xD5004B: assign_discriminators (tree-cfg.cc:1224) ==107792== by 0xD5004B: build_gimple_cfg (tree-cfg.cc:251) ==107792== by 0xD5004B: execute_build_cfg (tree-cfg.cc:371) $ egrep "^Config|^==" mk.out Configuring in x86_64-pc-linux-gnu/libgcc ==107792== Conditional jump or move depends on uninitialised value(s) So the problem occurs when building libgcc. Configure command is ../trunk.git/configure --prefix=/home/dcb/gcc/$PREFIX \ --disable-bootstrap \ --disable-multilib \ --disable-werror \ --with-pkgversion=$HASH \ --enable-checking=valgrind \ --enable-languages=c,c++ and to get -O3 into it, I have sed 's/-O2/-O3/' < Makefile > Makefile.tmp diff Makefile Makefile.tmp mv Makefile.tmp Makefile for the top-level Makefile.