On Tru64 5.1B with the Compaq C compiler, configure fails when finding
zlib because multiple incompatible flags are added to CFLAGS. It appears
the tests for these flags are passing even though the compiler doesn't
actually support them.
e.g.
configure: Checking if compiler 'cc' supports -Wno-pointer-sign
configure: Setting -Wno-pointer-sign
configure: Checking if compiler 'cc' supports -fno-strict-overflow
configure: Setting -fno-strict-overflow
configure: Checking for available hardened build flags:
configure: Setting -fPIE
However, the zlib check fails due to:
configure:3323: cc -o conftest -g -Wno-pointer-sign -fno-strict-overflow
-fPIE -pie conftest.c >&5
ld: Invalid flag usage: Wno-pointer-sign, -Wx,-option must appear after
-_SYSTYPE_SVR4
If the check for `-Wno-pointer-sign` is modified so that it doesn't
actually get added to CFLAGS, then the zlib check fails as
`-fno-strict-overflow` isn't supported.
configure:4845: checking for deflate in -lz
configure:4870: cc -o conftest -g -fno-strict-overflow -fPIE
-fstack-protector-strong -D_FORTIFY_SOURCE=2 -mfunction-return=thunk
-mindirect-branch=thunk -I/usr/util/include -L/usr/util/lib conftest.c
-lz >&5
ld: -fno-strict-overflow: Unknown flag
Larkin
