https://gcc.gnu.org/bugzilla/show_bug.cgi?id=65828
--- Comment #2 from Steven Noonan <steven at uplinklabs dot net> --- I just noticed that libtool appears to be stripping some of the arguments in LDFLAGS when invoking GCC: /bin/sh ../libtool --tag=CC --mode=link gcc -flto -Wall -Wstrict-prototypes -Werror=declaration-after-statement -Werror=missing-prototypes -Werror=implicit-function-declaration -Werror=pointer-arith -Werror=init-self -Werror=format=2 -Werror=missing-include-dirs -fvisibility=hidden -O2 -fsanitize=undefined -Wl,-Bsymbolic-functions -version-info 4400:0:4400 -export-dynamic -O2 -fsanitize=undefined -o libglib-2.0.la -rpath /usr/local/lib [[.lo files]] libcharset/libcharset.la pcre/libpcre.la -lpthread libtool: link: gcc -flto -shared -fPIC -DPIC [[.o files]] -Wl,--whole-archive libcharset/.libs/libcharset.a pcre/.libs/libpcre.a -Wl,--no-whole-archive -lpthread -flto -O2 -Wl,-Bsymbolic-functions -O2 -Wl,-soname -Wl,libglib-2.0.so.0 -o .libs/libglib-2.0.so.0.4400.0 In particular it dropped the -fsanitize=undefined flag. If I invoke the libtool-generated GCC command line with '-fsanitize=undefined' added then there's no ICE. $ gcc -flto -shared -fPIC -DPIC [[.o files]] -Wl,--whole-archive libcharset/.libs/libcharset.a pcre/.libs/libpcre.a -Wl,--no-whole-archive -lpthread -flto -O2 -Wl,-Bsymbolic-functions -O2 -Wl,-soname -Wl,libglib-2.0.so.0 -o .libs/libglib-2.0.so.0.4400.0 -fsanitize=undefined $ ls -cahl .libs/libglib-2.0.so.0.4400.0 -rwxr-xr-x 1 snoonan snoonan 4.3M Apr 21 03:31 .libs/libglib-2.0.so.0.4400.0 Hmm.
