+# serial 2
+
dnl Check whether the compiler supports particular flags.
dnl
-dnl Provides RRA_PROG_CC_FLAG, which checks whether a compiler supports a
-dnl given flag. If it does, the commands in the second argument are run. If
-dnl not, the commands in the third argument are run.
+dnl Provides RRA_PROG_CC_FLAG and RRA_PROG_LD_FLAG, which checks whether a
+dnl compiler supports a given flag for either compilation or linking,
+dnl respectively. If it does, the commands in the second argument are run.
+dnl If not, the commands in the third argument are run.
dnl
dnl Provides RRA_PROG_CC_WARNINGS_FLAGS, which checks whether a compiler
dnl supports a large set of warning flags and sets the WARNINGS_CFLAGS
dnl The canonical version of this file is maintained in the rra-c-util
dnl package, available at <https://www.eyrie.org/~eagle/software/rra-c-util/>.
dnl
-dnl Copyright 2016-2020 Russ Allbery <eagle@eyrie.org>
+dnl Copyright 2016-2023 Russ Allbery <eagle@eyrie.org>
dnl Copyright 2006, 2009, 2016
dnl by Internet Systems Consortium, Inc. ("ISC")
dnl
dnl Used to build the result cache name.
AC_DEFUN([_RRA_PROG_CC_FLAG_CACHE],
-[translit([rra_cv_compiler_c_$1], [-=+], [___])])
+[translit([rra_cv_compiler_c_$1], [-=+,], [____])])
+AC_DEFUN([_RRA_PROG_LD_FLAG_CACHE],
+[translit([rra_cv_linker_c_$1], [-=+,], [____])])
-dnl Check whether a given flag is supported by the compiler.
+dnl Check whether a given flag is supported by the compiler when compiling a C
+dnl source file.
AC_DEFUN([RRA_PROG_CC_FLAG],
[AC_REQUIRE([AC_PROG_CC])
AC_MSG_CHECKING([if $CC supports $1])
AC_CACHE_VAL([_RRA_PROG_CC_FLAG_CACHE([$1])],
[save_CFLAGS=$CFLAGS
+ AS_IF([test x"$CLANG" = xyes],
+ [CFLAGS="$CFLAGS -Werror=unknown-warning-option"])
AS_CASE([$1],
- [-Wno-*], [CFLAGS="$CFLAGS `echo "$1" | sed 's/-Wno-/-W/'`"],
- [*], [CFLAGS="$CFLAGS $1"])
+ [-Wno-*], [CFLAGS="$CFLAGS `AS_ECHO(["$1"]) | sed 's/-Wno-/-W/'`"],
+ [CFLAGS="$CFLAGS $1"])
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([], [int foo = 0;])],
[_RRA_PROG_CC_FLAG_CACHE([$1])=yes],
[_RRA_PROG_CC_FLAG_CACHE([$1])=no])
AC_MSG_RESULT([$_RRA_PROG_CC_FLAG_CACHE([$1])])
AS_IF([test x"$_RRA_PROG_CC_FLAG_CACHE([$1])" = xyes], [$2], [$3])])
+dnl Check whether a given flag is supported by the compiler when linking an
+dnl executable.
+AC_DEFUN([RRA_PROG_LD_FLAG],
+[AC_REQUIRE([AC_PROG_CC])
+ AC_MSG_CHECKING([if $CC supports $1 for linking])
+ AC_CACHE_VAL([_RRA_PROG_LD_FLAG_CACHE([$1])],
+ [save_LDFLAGS=$LDFLAGS
+ AS_IF([test x"$CLANG" = xyes],
+ [LDFLAGS="$LDFLAGS -Werror=unknown-warning-option"])
+ LDFLAGS="$LDFLAGS $1"
+ AC_LINK_IFELSE([AC_LANG_PROGRAM([], [int foo = 0;])],
+ [_RRA_PROG_LD_FLAG_CACHE([$1])=yes],
+ [_RRA_PROG_LD_FLAG_CACHE([$1])=no])
+ LDFLAGS=$save_LDFLAGS])
+ AC_MSG_RESULT([$_RRA_PROG_LD_FLAG_CACHE([$1])])
+ AS_IF([test x"$_RRA_PROG_LD_FLAG_CACHE([$1])" = xyes], [$2], [$3])])
+
dnl Determine the full set of viable warning flags for the current compiler.
dnl
dnl This is based partly on personal preference and is a fairly aggressive set
dnl -Wsign-conversion Too many fiddly changes for the benefit
dnl -Wstack-protector Too many false positives from small buffers
dnl
-dnl Last checked against gcc 9.2.1 (2019-09-01). -D_FORTIFY_SOURCE=2 enables
+dnl Last checked against gcc 13.2 (2023-12-25). -D_FORTIFY_SOURCE=2 enables
dnl warn_unused_result attribute markings on glibc functions on Linux, which
dnl catches a few more issues. Add -O2 because gcc won't find some warnings
dnl without optimization turned on.
dnl -Wdisabled-macro-expansion Triggers on libc (sigaction.sa_handler)
dnl -Wpadded Not an actual problem
dnl -Wreserved-id-macros Autoconf sets several of these normally
+dnl -Wreserved-identifer False positive with FD_ZERO
dnl -Wsign-conversion Too many fiddly changes for the benefit
dnl -Wtautological-pointer-compare False positives with for loops
dnl -Wundef Conflicts with Autoconf probe results
dnl -Wunreachable-code Happens with optional compilation
dnl -Wunreachable-code-return Other compilers get confused
+dnl -Wunsafe-buffer-usage Intended for C++, not applicable to C
dnl -Wunused-macros Often used on suppressed branches
dnl -Wused-but-marked-unused Happens a lot with conditional code
dnl
[WARNINGS_CFLAGS="-Werror"
m4_foreach_w([flag],
[-Weverything -Wno-cast-qual -Wno-disabled-macro-expansion -Wno-padded
- -Wno-sign-conversion -Wno-reserved-id-macro
+ -Wno-sign-conversion -Wno-reserved-id-macro -Wno-reserved-identifier
-Wno-tautological-pointer-compare -Wno-undef -Wno-unreachable-code
- -Wno-unreachable-code-return -Wno-unused-macros
- -Wno-used-but-marked-unused],
+ -Wno-unreachable-code-return -Wno-unsafe-buffer-usage
+ -Wno-unused-macros -Wno-used-but-marked-unused],
[RRA_PROG_CC_FLAG(flag,
[WARNINGS_CFLAGS="${WARNINGS_CFLAGS} flag"])])],
[WARNINGS_CFLAGS="-g -O2 -D_FORTIFY_SOURCE=2 -Werror"
m4_foreach_w([flag],
- [-fstrict-overflow -fstrict-aliasing -Wall -Wextra -Wformat=2
- -Wformat-overflow=2 -Wformat-signedness -Wformat-truncation=2
- -Wnull-dereference -Winit-self -Wswitch-enum -Wstrict-overflow=5
- -Wmissing-format-attribute -Walloc-zero -Wduplicated-branches
+ [-fstrict-overflow -fstrict-aliasing -fstrict-flex-arrays=3 -Wall
+ -Wextra -Wformat=2 -Wformat-overflow=2 -Wformat-signedness
+ -Wformat-truncation=2 -Wnull-dereference -Winit-self -Wswitch-enum
+ -Wstrict-overflow=5 -Wmissing-format-attribute -Walloc-zero
+ -Warith-conversion -Warray-bounds=3 -Wduplicated-branches
-Wduplicated-cond -Wtrampolines -Wfloat-equal
-Wdeclaration-after-statement -Wshadow -Wpointer-arith
-Wbad-function-cast -Wcast-align -Wwrite-strings -Wconversion
- -Wno-sign-conversion -Wdate-time -Wjump-misses-init -Wlogical-op
- -Wstrict-prototypes -Wold-style-definition -Wmissing-prototypes
- -Wmissing-declarations -Wnormalized=nfc -Wpacked -Wredundant-decls
- -Wrestrict -Wnested-externs -Winline -Wvla],
+ -Wno-sign-conversion -Wdate-time -Wjump-misses-init
+ -Wlogical-op -Wstrict-prototypes -Wold-style-definition
+ -Wmissing-prototypes -Wmissing-declarations -Wnormalized=nfc
+ -Wpacked -Wredundant-decls -Wrestrict -Wnested-externs -Winline
+ -Wvla -Wuse-after-free=3],
[RRA_PROG_CC_FLAG(flag,
[WARNINGS_CFLAGS="${WARNINGS_CFLAGS} flag"])])])
AC_SUBST([WARNINGS_CFLAGS])])
projects / kerberos / krb5-strength.git / blobdiff