configure: allow disabling warnings
When using `--enable-warnings`, it was not possible to disable warnings
via CFLAGS that got explicitly enabled. Now warnings are not enabled
anymore if they are explicitly disabled (or enabled) in CFLAGS. This
works for at least GCC, clang, and TCC as they have corresponding
`-Wno-` options for every warning.
Closes https://github.com/curl/curl/pull/5689
diff --git a/m4/curl-compilers.m4 b/m4/curl-compilers.m4
index e732a87..107dc6a 100644
--- a/m4/curl-compilers.m4
+++ b/m4/curl-compilers.m4
@@ -886,36 +886,36 @@
#
if test "$want_warnings" = "yes"; then
tmp_CFLAGS="$tmp_CFLAGS -pedantic"
- tmp_CFLAGS="$tmp_CFLAGS -Wall -Wextra"
- tmp_CFLAGS="$tmp_CFLAGS -Wpointer-arith -Wwrite-strings"
- tmp_CFLAGS="$tmp_CFLAGS -Wshadow"
- tmp_CFLAGS="$tmp_CFLAGS -Winline -Wnested-externs"
- tmp_CFLAGS="$tmp_CFLAGS -Wmissing-declarations"
- tmp_CFLAGS="$tmp_CFLAGS -Wmissing-prototypes"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [all extra])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [pointer-arith write-strings])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [shadow])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [inline nested-externs])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [missing-declarations])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [missing-prototypes])
tmp_CFLAGS="$tmp_CFLAGS -Wno-long-long"
- tmp_CFLAGS="$tmp_CFLAGS -Wfloat-equal"
- tmp_CFLAGS="$tmp_CFLAGS -Wno-multichar -Wsign-compare"
- tmp_CFLAGS="$tmp_CFLAGS -Wundef"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [float-equal])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [no-multichar sign-compare])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [undef])
tmp_CFLAGS="$tmp_CFLAGS -Wno-format-nonliteral"
- tmp_CFLAGS="$tmp_CFLAGS -Wendif-labels -Wstrict-prototypes"
- tmp_CFLAGS="$tmp_CFLAGS -Wdeclaration-after-statement"
- tmp_CFLAGS="$tmp_CFLAGS -Wcast-align"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [endif-labels strict-prototypes])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [declaration-after-statement])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [cast-align])
tmp_CFLAGS="$tmp_CFLAGS -Wno-system-headers"
- tmp_CFLAGS="$tmp_CFLAGS -Wshorten-64-to-32"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [shorten-64-to-32])
#
dnl Only clang 1.1 or later
if test "$compiler_num" -ge "101"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wunused"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [unused])
fi
#
dnl Only clang 2.8 or later
if test "$compiler_num" -ge "208"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wvla"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [vla])
fi
#
dnl Only clang 2.9 or later
if test "$compiler_num" -ge "209"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wshift-sign-overflow"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [shift-sign-overflow])
fi
#
dnl Only clang 3.2 or later
@@ -926,19 +926,19 @@
dnl mingw because the libtool wrapper executable causes them
;;
*)
- tmp_CFLAGS="$tmp_CFLAGS -Wmissing-variable-declarations"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [missing-variable-declarations])
;;
esac
fi
#
dnl Only clang 3.6 or later
if test "$compiler_num" -ge "306"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wdouble-promotion"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [double-promotion])
fi
#
dnl Only clang 3.9 or later
if test "$compiler_num" -ge "309"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wcomma"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [comma])
# avoid the varargs warning, fixed in 4.0
# https://bugs.llvm.org/show_bug.cgi?id=29140
if test "$compiler_num" -lt "400"; then
@@ -968,43 +968,45 @@
fi
#
dnl Set of options we believe *ALL* gcc versions support:
- tmp_CFLAGS="$tmp_CFLAGS -Wall -W"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [all])
+ tmp_CFLAGS="$tmp_CFLAGS -W"
#
dnl Only gcc 1.4 or later
if test "$compiler_num" -ge "104"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wpointer-arith -Wwrite-strings"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [pointer-arith write-strings])
dnl If not cross-compiling with a gcc older than 3.0
if test "x$cross_compiling" != "xyes" ||
test "$compiler_num" -ge "300"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wunused -Wshadow"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [unused shadow])
fi
fi
#
dnl Only gcc 2.7 or later
if test "$compiler_num" -ge "207"; then
- tmp_CFLAGS="$tmp_CFLAGS -Winline -Wnested-externs"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [inline nested-externs])
dnl If not cross-compiling with a gcc older than 3.0
if test "x$cross_compiling" != "xyes" ||
test "$compiler_num" -ge "300"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wmissing-declarations"
- tmp_CFLAGS="$tmp_CFLAGS -Wmissing-prototypes"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [missing-declarations])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [missing-prototypes])
fi
fi
#
dnl Only gcc 2.95 or later
if test "$compiler_num" -ge "295"; then
tmp_CFLAGS="$tmp_CFLAGS -Wno-long-long"
- tmp_CFLAGS="$tmp_CFLAGS -Wbad-function-cast"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [bad-function-cast])
fi
#
dnl Only gcc 2.96 or later
if test "$compiler_num" -ge "296"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wfloat-equal"
- tmp_CFLAGS="$tmp_CFLAGS -Wno-multichar -Wsign-compare"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [float-equal])
+ tmp_CFLAGS="$tmp_CFLAGS -Wno-multichar"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [sign-compare])
dnl -Wundef used only if gcc is 2.96 or later since we get
dnl lots of "`_POSIX_C_SOURCE' is not defined" in system
dnl headers with gcc 2.95.4 on FreeBSD 4.9
- tmp_CFLAGS="$tmp_CFLAGS -Wundef"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [undef])
fi
#
dnl Only gcc 2.97 or later
@@ -1023,13 +1025,13 @@
#
dnl Only gcc 3.3 or later
if test "$compiler_num" -ge "303"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wendif-labels -Wstrict-prototypes"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [endif-labels strict-prototypes])
fi
#
dnl Only gcc 3.4 or later
if test "$compiler_num" -ge "304"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wdeclaration-after-statement"
- tmp_CFLAGS="$tmp_CFLAGS -Wold-style-definition"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [declaration-after-statement])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [old-style-definition])
fi
#
dnl Only gcc 4.0 or later
@@ -1039,15 +1041,17 @@
#
dnl Only gcc 4.2 or later
if test "$compiler_num" -ge "402"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wcast-align"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [cast-align])
fi
#
dnl Only gcc 4.3 or later
if test "$compiler_num" -ge "403"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wtype-limits -Wold-style-declaration"
- tmp_CFLAGS="$tmp_CFLAGS -Wmissing-parameter-type -Wempty-body"
- tmp_CFLAGS="$tmp_CFLAGS -Wclobbered -Wignored-qualifiers"
- tmp_CFLAGS="$tmp_CFLAGS -Wconversion -Wno-sign-conversion -Wvla"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [type-limits old-style-declaration])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [missing-parameter-type empty-body])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [clobbered ignored-qualifiers])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [conversion])
+ tmp_CFLAGS="$tmp_CFLAGS -Wno-sign-conversion"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [vla])
dnl required for -Warray-bounds, included in -Wall
tmp_CFLAGS="$tmp_CFLAGS -ftree-vrp"
fi
@@ -1062,7 +1066,7 @@
#
dnl Only gcc 4.6 or later
if test "$compiler_num" -ge "406"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wdouble-promotion"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [double-promotion])
fi
#
dnl only gcc 4.8 or later
@@ -1077,18 +1081,19 @@
#
dnl Only gcc 6 or later
if test "$compiler_num" -ge "600"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wshift-negative-value"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [shift-negative-value])
tmp_CFLAGS="$tmp_CFLAGS -Wshift-overflow=2"
- tmp_CFLAGS="$tmp_CFLAGS -Wnull-dereference -fdelete-null-pointer-checks"
- tmp_CFLAGS="$tmp_CFLAGS -Wduplicated-cond"
- tmp_CFLAGS="$tmp_CFLAGS -Wunused-const-variable"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [null-dereference])
+ tmp_CFLAGS="$tmp_CFLAGS -fdelete-null-pointer-checks"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [duplicated-cond])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [unused-const-variable])
fi
#
dnl Only gcc 7 or later
if test "$compiler_num" -ge "700"; then
- tmp_CFLAGS="$tmp_CFLAGS -Wduplicated-branches"
- tmp_CFLAGS="$tmp_CFLAGS -Wrestrict"
- tmp_CFLAGS="$tmp_CFLAGS -Walloc-zero"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [duplicated-branches])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [restrict])
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [alloc-zero])
tmp_CFLAGS="$tmp_CFLAGS -Wformat-overflow=2"
tmp_CFLAGS="$tmp_CFLAGS -Wformat-truncation=2"
tmp_CFLAGS="$tmp_CFLAGS -Wimplicit-fallthrough=4"
@@ -1214,11 +1219,11 @@
#
if test "$want_warnings" = "yes"; then
dnl Activate all warnings
- tmp_CFLAGS="$tmp_CFLAGS -Wall"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [all])
dnl Make string constants be of type const char *
- tmp_CFLAGS="$tmp_CFLAGS -Wwrite-strings"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [write-strings])
dnl Warn use of unsupported GCC features ignored by TCC
- tmp_CFLAGS="$tmp_CFLAGS -Wunsupported"
+ CURL_ADD_COMPILER_WARNINGS([tmp_CFLAGS], [unsupported])
fi
;;
#
@@ -1645,3 +1650,24 @@
[$1]="$ac_var_stripped"
squeeze [$1]
])
+
+dnl CURL_ADD_COMPILER_WARNINGS (WARNING-LIST, NEW-WARNINGS)
+dnl -------------------------------------------------------
+dnl Contents of variable WARNING-LIST and NEW-WARNINGS are
+dnl handled as whitespace separated lists of words.
+dnl Add each compiler warning from NEW-WARNINGS that has not
+dnl been disabled via CFLAGS to WARNING-LIST.
+
+AC_DEFUN([CURL_ADD_COMPILER_WARNINGS], [
+ AC_REQUIRE([CURL_SHFUNC_SQUEEZE])dnl
+ ac_var_added_warnings=""
+ for warning in [$2]; do
+ CURL_VAR_MATCH(CFLAGS, [-Wno-$warning -W$warning])
+ if test "$ac_var_match_word" = "no"; then
+ ac_var_added_warnings="$ac_var_added_warnings -W$warning"
+ fi
+ done
+ dnl squeeze whitespace out of result
+ [$1]="$[$1] $ac_var_added_warnings"
+ squeeze [$1]
+])
