# manywarnings.m4 serial 8

dnl Copyright (C) 2008-2016 Free Software Foundation, Inc.

dnl This file is free software; the Free Software Foundation

dnl gives unlimited permission to copy and/or distribute it,

dnl with or without modifications, as long as this notice is preserved.

dnl From Simon Josefsson

# gl_MANYWARN_COMPLEMENT(OUTVAR, LISTVAR, REMOVEVAR)

# --------------------------------------------------

# Copy LISTVAR to OUTVAR except for the entries in REMOVEVAR.

# Elements separated by whitespace.  In set logic terms, the function

# does OUTVAR = LISTVAR \ REMOVEVAR.

AC_DEFUN([gl_MANYWARN_COMPLEMENT],

[

  gl_warn_set=

  set x $2; shift

  for gl_warn_item

  do

    case " $3 " in

      *" $gl_warn_item "*)

        ;;

      *)

        gl_warn_set="$gl_warn_set $gl_warn_item"

        ;;

    esac

  done

  $1=$gl_warn_set

])

# gl_MANYWARN_ALL_GCC(VARIABLE)

# -----------------------------

# Add all documented GCC warning parameters to variable VARIABLE.

# Note that you need to test them using gl_WARN_ADD if you want to

# make sure your gcc understands it.

AC_DEFUN([gl_MANYWARN_ALL_GCC],

[

  dnl First, check for some issues that only occur when combining multiple

  dnl gcc warning categories.

  AC_REQUIRE([AC_PROG_CC])

  if test -n "$GCC"; then

    dnl Check if -W -Werror -Wno-missing-field-initializers is supported

    dnl with the current $CC $CFLAGS $CPPFLAGS.

    AC_MSG_CHECKING([whether -Wno-missing-field-initializers is supported])

    AC_CACHE_VAL([gl_cv_cc_nomfi_supported], [

      gl_save_CFLAGS="$CFLAGS"

      CFLAGS="$CFLAGS -W -Werror -Wno-missing-field-initializers"

      AC_COMPILE_IFELSE(

        [AC_LANG_PROGRAM([[]], [[]])],

        [gl_cv_cc_nomfi_supported=yes],

        [gl_cv_cc_nomfi_supported=no])

      CFLAGS="$gl_save_CFLAGS"])

    AC_MSG_RESULT([$gl_cv_cc_nomfi_supported])

    if test "$gl_cv_cc_nomfi_supported" = yes; then

      dnl Now check whether -Wno-missing-field-initializers is needed

      dnl for the { 0, } construct.

      AC_MSG_CHECKING([whether -Wno-missing-field-initializers is needed])

      AC_CACHE_VAL([gl_cv_cc_nomfi_needed], [

        gl_save_CFLAGS="$CFLAGS"

        CFLAGS="$CFLAGS -W -Werror"

        AC_COMPILE_IFELSE(

          [AC_LANG_PROGRAM(

             [[int f (void)

               {

                 typedef struct { int a; int b; } s_t;

                 s_t s1 = { 0, };

                 return s1.b;

               }

             ]],

             [[]])],

          [gl_cv_cc_nomfi_needed=no],

          [gl_cv_cc_nomfi_needed=yes])

        CFLAGS="$gl_save_CFLAGS"

      ])

      AC_MSG_RESULT([$gl_cv_cc_nomfi_needed])

    fi

    dnl Next, check if -Werror -Wuninitialized is useful with the

    dnl user's choice of $CFLAGS; some versions of gcc warn that it

    dnl has no effect if -O is not also used

    AC_MSG_CHECKING([whether -Wuninitialized is supported])

    AC_CACHE_VAL([gl_cv_cc_uninitialized_supported], [

      gl_save_CFLAGS="$CFLAGS"

      CFLAGS="$CFLAGS -Werror -Wuninitialized"

      AC_COMPILE_IFELSE(

        [AC_LANG_PROGRAM([[]], [[]])],

        [gl_cv_cc_uninitialized_supported=yes],

        [gl_cv_cc_uninitialized_supported=no])

      CFLAGS="$gl_save_CFLAGS"])

    AC_MSG_RESULT([$gl_cv_cc_uninitialized_supported])

  fi

  # List all gcc warning categories.

  # To compare this list to your installed GCC's, run this Bash command:

  #

  # comm -3 \

  #  <(sed -n 's/^  *\(-[^ ]*\) .*/\1/p' manywarnings.m4 | sort) \

  #  <(gcc --help=warnings | sed -n 's/^  \(-[^ ]*\) .*/\1/p' | sort |

  #      grep -v -x -f <(

  #         awk '/^[^#]/ {print $1}' ../build-aux/gcc-warning.spec))

  gl_manywarn_set=

  for gl_manywarn_item in \

    -fno-common \

    -W \

    -Wabi \

    -Waddress \

    -Waggressive-loop-optimizations \

    -Wall \

    -Wattributes \

    -Wbad-function-cast \

    -Wbool-compare \

    -Wbuiltin-macro-redefined \

    -Wcast-align \

    -Wchar-subscripts \

    -Wchkp \

    -Wclobbered \

    -Wcomment \

    -Wcomments \

    -Wcoverage-mismatch \

    -Wcpp \

    -Wdate-time \

    -Wdeprecated \

    -Wdeprecated-declarations \

    -Wdesignated-init \

    -Wdisabled-optimization \

    -Wdiscarded-array-qualifiers \

    -Wdiscarded-qualifiers \

    -Wdiv-by-zero \

    -Wdouble-promotion \

    -Wduplicated-cond \

    -Wempty-body \

    -Wendif-labels \

    -Wenum-compare \

    -Wextra \

    -Wformat-contains-nul \

    -Wformat-extra-args \

    -Wformat-nonliteral \

    -Wformat-security \

    -Wformat-signedness \

    -Wformat-y2k \

    -Wformat-zero-length \

    -Wframe-address \

    -Wfree-nonheap-object \

    -Whsa \

    -Wignored-attributes \

    -Wignored-qualifiers \

    -Wimplicit \

    -Wimplicit-function-declaration \

    -Wimplicit-int \

    -Wincompatible-pointer-types \

    -Winit-self \

    -Winline \

    -Wint-conversion \

    -Wint-to-pointer-cast \

    -Winvalid-memory-model \

    -Winvalid-pch \

    -Wjump-misses-init \

    -Wlogical-not-parentheses \

    -Wlogical-op \

    -Wmain \

    -Wmaybe-uninitialized \

    -Wmemset-transposed-args \

    -Wmisleading-indentation \

    -Wmissing-braces \

    -Wmissing-declarations \

    -Wmissing-field-initializers \

    -Wmissing-include-dirs \

    -Wmissing-parameter-type \

    -Wmissing-prototypes \

    -Wmultichar \

    -Wnarrowing \

    -Wnested-externs \

    -Wnonnull \

    -Wnonnull-compare \

    -Wnull-dereference \

    -Wodr \

    -Wold-style-declaration \

    -Wold-style-definition \

    -Wopenmp-simd \

    -Woverflow \

    -Woverlength-strings \

    -Woverride-init \

    -Wpacked \

    -Wpacked-bitfield-compat \

    -Wparentheses \

    -Wpointer-arith \

    -Wpointer-sign \

    -Wpointer-to-int-cast \

    -Wpragmas \

    -Wreturn-local-addr \

    -Wreturn-type \

    -Wscalar-storage-order \

    -Wsequence-point \

    -Wshadow \

    -Wshift-count-negative \

    -Wshift-count-overflow \

    -Wshift-negative-value \

    -Wsizeof-array-argument \

    -Wsizeof-pointer-memaccess \

    -Wstack-protector \

    -Wstrict-aliasing \

    -Wstrict-overflow \

    -Wstrict-prototypes \

    -Wsuggest-attribute=const \

    -Wsuggest-attribute=format \

    -Wsuggest-attribute=noreturn \

    -Wsuggest-attribute=pure \

    -Wsuggest-final-methods \

    -Wsuggest-final-types \

    -Wswitch \

    -Wswitch-bool \

    -Wswitch-default \

    -Wsync-nand \

    -Wsystem-headers \

    -Wtautological-compare \

    -Wtrampolines \

    -Wtrigraphs \

    -Wtype-limits \

    -Wuninitialized \

    -Wunknown-pragmas \

    -Wunsafe-loop-optimizations \

    -Wunused \

    -Wunused-but-set-parameter \

    -Wunused-but-set-variable \

    -Wunused-function \

    -Wunused-label \

    -Wunused-local-typedefs \

    -Wunused-macros \

    -Wunused-parameter \

    -Wunused-result \

    -Wunused-value \

    -Wunused-variable \

    -Wvarargs \

    -Wvariadic-macros \

    -Wvector-operation-performance \

    -Wvla \

    -Wvolatile-register-var \

    -Wwrite-strings \

    \

    ; do

    gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item"

  done

  # gcc --help=warnings outputs an unusual form for these options; list

  # them here so that the above 'comm' command doesn't report a false match.

  gl_manywarn_set="$gl_manywarn_set -Warray-bounds=2"

  gl_manywarn_set="$gl_manywarn_set -Wnormalized=nfc"

  gl_manywarn_set="$gl_manywarn_set -Wshift-overflow=2"

  gl_manywarn_set="$gl_manywarn_set -Wunused-const-variable=2"

  # These are needed for older GCC versions.

  if test -n "$GCC"; then

    case `($CC --version) 2>/dev/null` in

      'gcc (GCC) '[[0-3]].* | \

      'gcc (GCC) '4.[[0-7]].*)

        gl_manywarn_set="$gl_manywarn_set -fdiagnostics-show-option"

        gl_manywarn_set="$gl_manywarn_set -funit-at-a-time"

          ;;

    esac

  fi

  # Disable specific options as needed.

  if test "$gl_cv_cc_nomfi_needed" = yes; then

    gl_manywarn_set="$gl_manywarn_set -Wno-missing-field-initializers"

  fi

  if test "$gl_cv_cc_uninitialized_supported" = no; then

    gl_manywarn_set="$gl_manywarn_set -Wno-uninitialized"

  fi

  $1=$gl_manywarn_set

])