From e716585235b175de767d3b210f0a963457dfa77f Mon Sep 17 00:00:00 2001 From: Tom Lane Date: Sat, 16 Jun 2018 15:34:07 -0400 Subject: [PATCH] Use -Wno-format-truncation and -Wno-stringop-truncation, if available. gcc 8 has started emitting some warnings that are largely useless for our purposes, particularly since they complain about code following the project-standard coding convention that path names are assumed to be shorter than MAXPGPATH. Even if we make the effort to remove that assumption in some future release, the changes wouldn't get back-patched. Hence, just suppress these warnings, on compilers that have these switches. Backpatch to all supported branches. Discussion: https://postgr.es/m/1524563856.26306.9.camel@gunduz.org --- configure | 88 ++++++++++++++++++++++++++++++++++++++++++++++++++++ configure.in | 12 +++++++ 2 files changed, 100 insertions(+) diff --git a/configure b/configure index 3d219c802ba..000c63d40c4 100755 --- a/configure +++ b/configure @@ -5815,6 +5815,7 @@ fi # We want to suppress clang's unhelpful unused-command-line-argument warnings # but gcc won't complain about unrecognized -Wno-foo switches, so we have to # test for the positive form and if that works, add the negative form + NOT_THE_CFLAGS="" { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -Wunused-command-line-argument, for NOT_THE_CFLAGS" >&5 $as_echo_n "checking whether ${CC} supports -Wunused-command-line-argument, for NOT_THE_CFLAGS... " >&6; } if ${pgac_cv_prog_CC_cflags__Wunused_command_line_argument+:} false; then : @@ -5857,6 +5858,93 @@ fi if test -n "$NOT_THE_CFLAGS"; then CFLAGS="$CFLAGS -Wno-unused-command-line-argument" fi + # Similarly disable useless truncation warnings from gcc 8+ + NOT_THE_CFLAGS="" + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -Wformat-truncation, for NOT_THE_CFLAGS" >&5 +$as_echo_n "checking whether ${CC} supports -Wformat-truncation, for NOT_THE_CFLAGS... " >&6; } +if ${pgac_cv_prog_CC_cflags__Wformat_truncation+:} false; then : + $as_echo_n "(cached) " >&6 +else + pgac_save_CFLAGS=$CFLAGS +pgac_save_CC=$CC +CC=${CC} +CFLAGS="${NOT_THE_CFLAGS} -Wformat-truncation" +ac_save_c_werror_flag=$ac_c_werror_flag +ac_c_werror_flag=yes +cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + +int +main () +{ + + ; + return 0; +} +_ACEOF +if ac_fn_c_try_compile "$LINENO"; then : + pgac_cv_prog_CC_cflags__Wformat_truncation=yes +else + pgac_cv_prog_CC_cflags__Wformat_truncation=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext +ac_c_werror_flag=$ac_save_c_werror_flag +CFLAGS="$pgac_save_CFLAGS" +CC="$pgac_save_CC" +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__Wformat_truncation" >&5 +$as_echo "$pgac_cv_prog_CC_cflags__Wformat_truncation" >&6; } +if test x"$pgac_cv_prog_CC_cflags__Wformat_truncation" = x"yes"; then + NOT_THE_CFLAGS="${NOT_THE_CFLAGS} -Wformat-truncation" +fi + + + if test -n "$NOT_THE_CFLAGS"; then + CFLAGS="$CFLAGS -Wno-format-truncation" + fi + NOT_THE_CFLAGS="" + { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether ${CC} supports -Wstringop-truncation, for NOT_THE_CFLAGS" >&5 +$as_echo_n "checking whether ${CC} supports -Wstringop-truncation, for NOT_THE_CFLAGS... " >&6; } +if ${pgac_cv_prog_CC_cflags__Wstringop_truncation+:} false; then : + $as_echo_n "(cached) " >&6 +else + pgac_save_CFLAGS=$CFLAGS +pgac_save_CC=$CC +CC=${CC} +CFLAGS="${NOT_THE_CFLAGS} -Wstringop-truncation" +ac_save_c_werror_flag=$ac_c_werror_flag +ac_c_werror_flag=yes +cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + +int +main () +{ + + ; + return 0; +} +_ACEOF +if ac_fn_c_try_compile "$LINENO"; then : + pgac_cv_prog_CC_cflags__Wstringop_truncation=yes +else + pgac_cv_prog_CC_cflags__Wstringop_truncation=no +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext +ac_c_werror_flag=$ac_save_c_werror_flag +CFLAGS="$pgac_save_CFLAGS" +CC="$pgac_save_CC" +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $pgac_cv_prog_CC_cflags__Wstringop_truncation" >&5 +$as_echo "$pgac_cv_prog_CC_cflags__Wstringop_truncation" >&6; } +if test x"$pgac_cv_prog_CC_cflags__Wstringop_truncation" = x"yes"; then + NOT_THE_CFLAGS="${NOT_THE_CFLAGS} -Wstringop-truncation" +fi + + + if test -n "$NOT_THE_CFLAGS"; then + CFLAGS="$CFLAGS -Wno-stringop-truncation" + fi elif test "$ICC" = yes; then # Intel's compiler has a bug/misoptimization in checking for # division by NAN (NaN == 0), -mp1 fixes it, so add it to the CFLAGS. diff --git a/configure.in b/configure.in index 862d8b128d5..03fc5023a46 100644 --- a/configure.in +++ b/configure.in @@ -498,10 +498,22 @@ if test "$GCC" = yes -a "$ICC" = no; then # We want to suppress clang's unhelpful unused-command-line-argument warnings # but gcc won't complain about unrecognized -Wno-foo switches, so we have to # test for the positive form and if that works, add the negative form + NOT_THE_CFLAGS="" PGAC_PROG_CC_VAR_OPT(NOT_THE_CFLAGS, [-Wunused-command-line-argument]) if test -n "$NOT_THE_CFLAGS"; then CFLAGS="$CFLAGS -Wno-unused-command-line-argument" fi + # Similarly disable useless truncation warnings from gcc 8+ + NOT_THE_CFLAGS="" + PGAC_PROG_CC_VAR_OPT(NOT_THE_CFLAGS, [-Wformat-truncation]) + if test -n "$NOT_THE_CFLAGS"; then + CFLAGS="$CFLAGS -Wno-format-truncation" + fi + NOT_THE_CFLAGS="" + PGAC_PROG_CC_VAR_OPT(NOT_THE_CFLAGS, [-Wstringop-truncation]) + if test -n "$NOT_THE_CFLAGS"; then + CFLAGS="$CFLAGS -Wno-stringop-truncation" + fi elif test "$ICC" = yes; then # Intel's compiler has a bug/misoptimization in checking for # division by NAN (NaN == 0), -mp1 fixes it, so add it to the CFLAGS.