diff options
| -rw-r--r-- | Doc/using/configure.rst | 5 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Build/2022-09-14-10-38-15.gh-issue-96821.Zk2a9c.rst | 3 | ||||
| -rwxr-xr-x | configure | 78 | ||||
| -rw-r--r-- | configure.ac | 54 |
4 files changed, 122 insertions, 18 deletions
diff --git a/Doc/using/configure.rst b/Doc/using/configure.rst index 8fa8d25..8936bd3 100644 --- a/Doc/using/configure.rst +++ b/Doc/using/configure.rst @@ -326,6 +326,11 @@ also be used to improve performance. Enable C-level code profiling with ``gprof`` (disabled by default). +.. cmdoption:: --with-strict-overflow + + Add ``-fstrict-overflow`` to the C compiler flags (by default we add + ``-fno-strict-overflow`` instead). + .. _debug-build: diff --git a/Misc/NEWS.d/next/Build/2022-09-14-10-38-15.gh-issue-96821.Zk2a9c.rst b/Misc/NEWS.d/next/Build/2022-09-14-10-38-15.gh-issue-96821.Zk2a9c.rst new file mode 100644 index 0000000..865cfde --- /dev/null +++ b/Misc/NEWS.d/next/Build/2022-09-14-10-38-15.gh-issue-96821.Zk2a9c.rst @@ -0,0 +1,3 @@ +Explicitly mark C extension modules that need defined signed integer overflow, +and add a configure option :option:`--with-strict-overflow`. +Patch by Matthias Görgens and Shantanu Jain. @@ -1054,6 +1054,7 @@ with_assertions enable_optimizations with_lto enable_bolt +with_strict_overflow with_dsymutil with_address_sanitizer with_memory_sanitizer @@ -1825,6 +1826,8 @@ Optional Packages: --with-lto=[full|thin|no|yes] enable Link-Time-Optimization in any build (default is no) + --with-strict-overflow if 'yes', add -fstrict-overflow to CFLAGS, else add + -fno-strict-overflow (default is no) --with-dsymutil link debug information into final executable with dsymutil in macOS (default is no) --with-address-sanitizer @@ -8376,6 +8379,64 @@ case $CC in fi esac +save_CFLAGS=$CFLAGS +CFLAGS="-fstrict-overflow -fno-strict-overflow" +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking if $CC supports -fstrict-overflow and -fno-strict-overflow" >&5 +$as_echo_n "checking if $CC supports -fstrict-overflow and -fno-strict-overflow... " >&6; } +if ${ac_cv_cc_supports_fstrict_overflow+:} false; then : + $as_echo_n "(cached) " >&6 +else + cat confdefs.h - <<_ACEOF >conftest.$ac_ext +/* end confdefs.h. */ + +int +main () +{ + + ; + return 0; +} +_ACEOF +if ac_fn_c_try_compile "$LINENO"; then : + ac_cv_cc_supports_fstrict_overflow=yes +else + ac_cv_cc_supports_fstrict_overflow=no + +fi +rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext + +fi +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_cc_supports_fstrict_overflow" >&5 +$as_echo "$ac_cv_cc_supports_fstrict_overflow" >&6; } +CFLAGS=$save_CFLAGS + +if test "x$ac_cv_cc_supports_fstrict_overflow" = xyes; then : + STRICT_OVERFLOW_CFLAGS="-fstrict-overflow" + NO_STRICT_OVERFLOW_CFLAGS="-fno-strict-overflow" +else + STRICT_OVERFLOW_CFLAGS="" + NO_STRICT_OVERFLOW_CFLAGS="" +fi + +{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for --with-strict-overflow" >&5 +$as_echo_n "checking for --with-strict-overflow... " >&6; } + +# Check whether --with-strict-overflow was given. +if test "${with_strict_overflow+set}" = set; then : + withval=$with_strict_overflow; + if test "x$ac_cv_cc_supports_fstrict_overflow" = xno; then : + { $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: --with-strict-overflow=yes requires a compiler that supports -fstrict-overflow" >&5 +$as_echo "$as_me: WARNING: --with-strict-overflow=yes requires a compiler that supports -fstrict-overflow" >&2;} +fi + +else + with_strict_overflow=no + +fi + +{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $with_strict_overflow" >&5 +$as_echo "$with_strict_overflow" >&6; } + # Check if CC supports -Og optimization level save_CFLAGS=$CFLAGS CFLAGS="-Og" @@ -8428,15 +8489,8 @@ if test "${OPT-unset}" = "unset" then case $GCC in yes) - # For gcc 4.x we need to use -fwrapv so lets check if its supported - if "$CC" -v --help 2>/dev/null |grep -- -fwrapv > /dev/null; then - WRAP="-fwrapv" - fi - if test -n "${cc_is_clang}" then - # Clang also needs -fwrapv - WRAP="-fwrapv" # bpo-30104: disable strict aliasing to compile correctly dtoa.c, # see Makefile.pre.in for more information CFLAGS_ALIASING="-fno-strict-aliasing" @@ -8447,7 +8501,7 @@ then if test "$Py_DEBUG" = 'true' ; then OPT="-g $PYDEBUG_CFLAGS -Wall" else - OPT="-g $WRAP -O3 -Wall" + OPT="-g -O3 -Wall" fi ;; *) @@ -8580,6 +8634,12 @@ UNIVERSAL_ARCH_FLAGS= # tweak BASECFLAGS based on compiler and platform +if test "x$with_strict_overflow" = xyes; then : + BASECFLAGS="$BASECFLAGS $STRICT_OVERFLOW_CFLAGS" +else + BASECFLAGS="$BASECFLAGS $NO_STRICT_OVERFLOW_CFLAGS" +fi + case $GCC in yes) CFLAGS_NODIST="$CFLAGS_NODIST -std=c11" @@ -27049,7 +27109,7 @@ fi as_fn_append MODULE_BLOCK "MODULE__CTYPES_STATE=$py_cv_module__ctypes$as_nl" if test "x$py_cv_module__ctypes" = xyes; then : - as_fn_append MODULE_BLOCK "MODULE__CTYPES_CFLAGS=$LIBFFI_CFLAGS$as_nl" + as_fn_append MODULE_BLOCK "MODULE__CTYPES_CFLAGS=$NO_STRICT_OVERFLOW_CFLAGS $LIBFFI_CFLAGS$as_nl" as_fn_append MODULE_BLOCK "MODULE__CTYPES_LDFLAGS=$LIBFFI_LIBS$as_nl" fi diff --git a/configure.ac b/configure.ac index 982f669..31b7a21 100644 --- a/configure.ac +++ b/configure.ac @@ -2073,6 +2073,45 @@ case $CC in fi esac +dnl Historically, some of our code assumed that signed integer overflow +dnl is defined behaviour via twos-complement. +dnl Set STRICT_OVERFLOW_CFLAGS and NO_STRICT_OVERFLOW_CFLAGS depending on compiler support. +dnl Pass the latter to modules that depend on such behaviour. +_SAVE_VAR([CFLAGS]) +CFLAGS="-fstrict-overflow -fno-strict-overflow" +AC_CACHE_CHECK([if $CC supports -fstrict-overflow and -fno-strict-overflow], + [ac_cv_cc_supports_fstrict_overflow], + AC_COMPILE_IFELSE( + [AC_LANG_PROGRAM([[]], [[]])], + [ac_cv_cc_supports_fstrict_overflow=yes], + [ac_cv_cc_supports_fstrict_overflow=no] + ) +) +_RESTORE_VAR([CFLAGS]) + +AS_VAR_IF([ac_cv_cc_supports_fstrict_overflow], [yes], + [STRICT_OVERFLOW_CFLAGS="-fstrict-overflow" + NO_STRICT_OVERFLOW_CFLAGS="-fno-strict-overflow"], + [STRICT_OVERFLOW_CFLAGS="" + NO_STRICT_OVERFLOW_CFLAGS=""]) + +AC_MSG_CHECKING([for --with-strict-overflow]) +AC_ARG_WITH([strict-overflow], + AS_HELP_STRING( + [--with-strict-overflow], + [if 'yes', add -fstrict-overflow to CFLAGS, else add -fno-strict-overflow (default is no)] + ), + [ + AS_VAR_IF( + [ac_cv_cc_supports_fstrict_overflow], [no], + [AC_MSG_WARN([--with-strict-overflow=yes requires a compiler that supports -fstrict-overflow])], + [] + ) + ], + [with_strict_overflow=no] +) +AC_MSG_RESULT([$with_strict_overflow]) + # Check if CC supports -Og optimization level _SAVE_VAR([CFLAGS]) CFLAGS="-Og" @@ -2103,15 +2142,8 @@ if test "${OPT-unset}" = "unset" then case $GCC in yes) - # For gcc 4.x we need to use -fwrapv so lets check if its supported - if "$CC" -v --help 2>/dev/null |grep -- -fwrapv > /dev/null; then - WRAP="-fwrapv" - fi - if test -n "${cc_is_clang}" then - # Clang also needs -fwrapv - WRAP="-fwrapv" # bpo-30104: disable strict aliasing to compile correctly dtoa.c, # see Makefile.pre.in for more information CFLAGS_ALIASING="-fno-strict-aliasing" @@ -2122,7 +2154,7 @@ then if test "$Py_DEBUG" = 'true' ; then OPT="-g $PYDEBUG_CFLAGS -Wall" else - OPT="-g $WRAP -O3 -Wall" + OPT="-g -O3 -Wall" fi ;; *) @@ -2237,6 +2269,10 @@ AC_DEFUN([PY_CHECK_CC_WARNING], [ ]) # tweak BASECFLAGS based on compiler and platform +AS_VAR_IF([with_strict_overflow], [yes], + [BASECFLAGS="$BASECFLAGS $STRICT_OVERFLOW_CFLAGS"], + [BASECFLAGS="$BASECFLAGS $NO_STRICT_OVERFLOW_CFLAGS"]) + case $GCC in yes) CFLAGS_NODIST="$CFLAGS_NODIST -std=c11" @@ -7213,7 +7249,7 @@ PY_STDLIB_MOD([_crypt], [$LIBCRYPT_CFLAGS], [$LIBCRYPT_LIBS]) PY_STDLIB_MOD([_ctypes], [], [test "$have_libffi" = yes], - [$LIBFFI_CFLAGS], [$LIBFFI_LIBS]) + [$NO_STRICT_OVERFLOW_CFLAGS $LIBFFI_CFLAGS], [$LIBFFI_LIBS]) PY_STDLIB_MOD([_curses], [], [test "$have_curses" != "no"], [$CURSES_CFLAGS], [$CURSES_LIBS] |