Merge gnulib module manywarnings-cxx into manywarnings

Preparation for pushing it upstream

3 files changed, 359 insertions, 49 deletions

diff --git a/gl/m4/manywarnings-cxx.m4 b/gl/m4/manywarnings.m4
index 12c81b9..1d11973 100644
--- a/gl/m4/manywarnings-cxx.m4
+++ b/gl/m4/manywarnings.m4
@@ -28,6 +28,253 @@ AC_DEFUN([gl_MANYWARN_COMPLEMENT],
   $1=$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
+])
+
 # gl_MANYWARN_ALL_GXX(VARIABLE)
 # -----------------------------
 # Add all documented G++ warning parameters to variable VARIABLE.
@@ -35,6 +282,8 @@ AC_DEFUN([gl_MANYWARN_COMPLEMENT],
 # make sure your gcc understands it.
 AC_DEFUN([gl_MANYWARN_ALL_GXX],
 [
+  AC_LANG_PUSH([C++])
+
   dnl First, check for some issues that only occur when combining multiple
   dnl gcc warning categories.
   AC_REQUIRE([AC_PROG_CXX])
@@ -43,21 +292,21 @@ AC_DEFUN([gl_MANYWARN_ALL_GXX],
     dnl Check if -W -Werror -Wno-missing-field-initializers is supported
     dnl with the current $CXX $CXXFLAGS $CPPFLAGS.
     AC_MSG_CHECKING([whether -Wno-missing-field-initializers is supported])
-    AC_CACHE_VAL([gl_cv_cc_nomfi_supported], [
+    AC_CACHE_VAL([gl_cv_cxx_nomfi_supported], [
       gl_save_CXXFLAGS="$CXXFLAGS"
       CXXFLAGS="$CXXFLAGS -W -Werror -Wno-missing-field-initializers"
       AC_COMPILE_IFELSE(
         [AC_LANG_PROGRAM([[]], [[]])],
-        [gl_cv_cc_nomfi_supported=yes],
-        [gl_cv_cc_nomfi_supported=no])
+        [gl_cv_cxx_nomfi_supported=yes],
+        [gl_cv_cxx_nomfi_supported=no])
       CXXFLAGS="$gl_save_CXXFLAGS"])
-    AC_MSG_RESULT([$gl_cv_cc_nomfi_supported])
+    AC_MSG_RESULT([$gl_cv_cxx_nomfi_supported])
 
-    if test "$gl_cv_cc_nomfi_supported" = yes; then
+    if test "$gl_cv_cxx_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], [
+      AC_CACHE_VAL([gl_cv_cxx_nomfi_needed], [
         gl_save_CXXFLAGS="$CXXFLAGS"
         CXXFLAGS="$CXXFLAGS -W -Werror"
         AC_COMPILE_IFELSE(
@@ -70,26 +319,26 @@ AC_DEFUN([gl_MANYWARN_ALL_GXX],
                }
              ]],
              [[]])],
-          [gl_cv_cc_nomfi_needed=no],
-          [gl_cv_cc_nomfi_needed=yes])
+          [gl_cv_cxx_nomfi_needed=no],
+          [gl_cv_cxx_nomfi_needed=yes])
         CXXFLAGS="$gl_save_CXXFLAGS"
       ])
-      AC_MSG_RESULT([$gl_cv_cc_nomfi_needed])
+      AC_MSG_RESULT([$gl_cv_cxx_nomfi_needed])
     fi
 
     dnl Next, check if -Werror -Wuninitialized is useful with the
     dnl user's choice of $CXXFLAGS; some versions of gcc warn that it
     dnl has no effect if -O is not also used
     AC_MSG_CHECKING([whether -Wuninitialized is supported])
-    AC_CACHE_VAL([gl_cv_cc_uninitialized_supported], [
+    AC_CACHE_VAL([gl_cv_cxx_uninitialized_supported], [
       gl_save_CXXFLAGS="$CXXFLAGS"
       CXXFLAGS="$CXXFLAGS -Werror -Wuninitialized"
       AC_COMPILE_IFELSE(
         [AC_LANG_PROGRAM([[]], [[]])],
-        [gl_cv_cc_uninitialized_supported=yes],
-        [gl_cv_cc_uninitialized_supported=no])
+        [gl_cv_cxx_uninitialized_supported=yes],
+        [gl_cv_cxx_uninitialized_supported=no])
       CXXFLAGS="$gl_save_CXXFLAGS"])
-    AC_MSG_RESULT([$gl_cv_cc_uninitialized_supported])
+    AC_MSG_RESULT([$gl_cv_cxx_uninitialized_supported])
 
   fi
 
@@ -97,7 +346,7 @@ AC_DEFUN([gl_MANYWARN_ALL_GXX],
   # To compare this list to your installed GCC's, run this Bash command:
   #
   # comm -3 \
-  #  <(sed -n 's/^  *\(-[^ ]*\) .*/\1/p' manywarnings-cxx.m4 | sort) \
+  #  <(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/g++-warning.spec))
@@ -258,31 +507,15 @@ AC_DEFUN([gl_MANYWARN_ALL_GXX],
   fi
 
   # Disable specific options as needed.
-  if test "$gl_cv_cc_nomfi_needed" = yes; then
+  if test "$gl_cv_cxx_nomfi_needed" = yes; then
     gl_manywarn_set="$gl_manywarn_set -Wno-missing-field-initializers"
   fi
 
-  if test "$gl_cv_cc_uninitialized_supported" = no; then
+  if test "$gl_cv_cxx_uninitialized_supported" = no; then
     gl_manywarn_set="$gl_manywarn_set -Wno-uninitialized"
   fi
 
   $1=$gl_manywarn_set
-])
 
-# gl_CXX_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS],
-#             [PROGRAM = AC_LANG_PROGRAM()])
-# ---------------------------------------------
-# Adds parameter to WARN_CXXFLAGS if the compiler supports it when
-# compiling PROGRAM.  For example, gl_CXX_WARN_ADD([-Wparentheses]).
-#
-# If VARIABLE is a variable name, AC_SUBST it.
-AC_DEFUN([gl_CXX_WARN_ADD],
-[AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS])
-gl_COMPILER_OPTION_IF([$1],
-  [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CXXFLAGS]], [[$2]]), [" $1"])],
-  [],
-  [$3])
-m4_ifval([$2],
-         [AS_LITERAL_IF([$2], [AC_SUBST([$2])])],
-         [AC_SUBST([WARN_CXXFLAGS])])dnl
+  AC_LANG_POP([C++])
 ])
diff --git a/gl/m4/warnings.m4 b/gl/m4/warnings.m4
new file mode 100644
index 0000000..7aafa0b
--- /dev/null
+++ b/gl/m4/warnings.m4
@@ -0,0 +1,93 @@
+# warnings.m4 serial 11
+dnl Copyright (C) 2008-2017 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_AS_VAR_APPEND(VAR, VALUE)
+# ----------------------------
+# Provide the functionality of AS_VAR_APPEND if Autoconf does not have it.
+m4_ifdef([AS_VAR_APPEND],
+[m4_copy([AS_VAR_APPEND], [gl_AS_VAR_APPEND])],
+[m4_define([gl_AS_VAR_APPEND],
+[AS_VAR_SET([$1], [AS_VAR_GET([$1])$2])])])
+
+
+# gl_COMPILER_OPTION_IF(OPTION, [IF-SUPPORTED], [IF-NOT-SUPPORTED],
+#                       [PROGRAM = AC_LANG_PROGRAM()])
+# -----------------------------------------------------------------
+# Check if the compiler supports OPTION when compiling PROGRAM.
+#
+# FIXME: gl_Warn must be used unquoted until we can assume Autoconf
+# 2.64 or newer.
+AC_DEFUN([gl_COMPILER_OPTION_IF],
+[AS_VAR_PUSHDEF([gl_Warn], [gl_cv_warn_[]_AC_LANG_ABBREV[]_$1])dnl
+AS_VAR_PUSHDEF([gl_Flags], [_AC_LANG_PREFIX[]FLAGS])dnl
+AS_LITERAL_IF([$1],
+  [m4_pushdef([gl_Positive], m4_bpatsubst([$1], [^-Wno-], [-W]))],
+  [gl_positive="$1"
+case $gl_positive in
+  -Wno-*) gl_positive=-W`expr "X$gl_positive" : 'X-Wno-\(.*\)'` ;;
+esac
+m4_pushdef([gl_Positive], [$gl_positive])])dnl
+AC_CACHE_CHECK([whether _AC_LANG compiler handles $1], m4_defn([gl_Warn]), [
+  gl_save_compiler_FLAGS="$gl_Flags"
+  gl_AS_VAR_APPEND(m4_defn([gl_Flags]),
+    [" $gl_unknown_warnings_are_errors ]m4_defn([gl_Positive])["])
+  AC_LINK_IFELSE([m4_default([$4], [AC_LANG_PROGRAM([])])],
+                 [AS_VAR_SET(gl_Warn, [yes])],
+                 [AS_VAR_SET(gl_Warn, [no])])
+  gl_Flags="$gl_save_compiler_FLAGS"
+])
+AS_VAR_IF(gl_Warn, [yes], [$2], [$3])
+m4_popdef([gl_Positive])dnl
+AS_VAR_POPDEF([gl_Flags])dnl
+AS_VAR_POPDEF([gl_Warn])dnl
+])
+
+# gl_UNKNOWN_WARNINGS_ARE_ERRORS
+# ------------------------------
+# Clang doesn't complain about unknown warning options unless one also
+# specifies -Wunknown-warning-option -Werror.  Detect this.
+AC_DEFUN([gl_UNKNOWN_WARNINGS_ARE_ERRORS],
+[gl_COMPILER_OPTION_IF([-Werror -Wunknown-warning-option],
+   [gl_unknown_warnings_are_errors='-Wunknown-warning-option -Werror'],
+   [gl_unknown_warnings_are_errors=])])
+
+# gl_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS],
+#             [PROGRAM = AC_LANG_PROGRAM()])
+# ---------------------------------------------
+# Adds parameter to WARN_CFLAGS if the compiler supports it when
+# compiling PROGRAM.  For example, gl_WARN_ADD([-Wparentheses]).
+#
+# If VARIABLE is a variable name, AC_SUBST it.
+AC_DEFUN([gl_WARN_ADD],
+[AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS])
+gl_COMPILER_OPTION_IF([$1],
+  [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CFLAGS]], [[$2]]), [" $1"])],
+  [],
+  [$3])
+m4_ifval([$2],
+         [AS_LITERAL_IF([$2], [AC_SUBST([$2])])],
+         [AC_SUBST([WARN_CFLAGS])])dnl
+])
+
+# gl_CXX_WARN_ADD(OPTION, [VARIABLE = WARN_CFLAGS],
+#             [PROGRAM = AC_LANG_PROGRAM()])
+# ---------------------------------------------
+# Adds parameter to WARN_CXXFLAGS if the compiler supports it when
+# compiling PROGRAM.  For example, gl_CXX_WARN_ADD([-Wparentheses]).
+#
+# If VARIABLE is a variable name, AC_SUBST it.
+AC_DEFUN([gl_CXX_WARN_ADD],
+[AC_REQUIRE([gl_UNKNOWN_WARNINGS_ARE_ERRORS])
+gl_COMPILER_OPTION_IF([$1],
+  [gl_AS_VAR_APPEND(m4_if([$2], [], [[WARN_CXXFLAGS]], [[$2]]), [" $1"])],
+  [],
+  [$3])
+m4_ifval([$2],
+         [AS_LITERAL_IF([$2], [AC_SUBST([$2])])],
+         [AC_SUBST([WARN_CXXFLAGS])])dnl
+])
diff --git a/gl/modules/manywarnings-cxx b/gl/modules/manywarnings-cxx
deleted file mode 100644
index cf7acf5..0000000
--- a/gl/modules/manywarnings-cxx
+++ /dev/null
@@ -1,16 +0,0 @@
-Description:
-Helper M4 functions to help work out a set of warning parameters to use.
-
-Files:
-m4/manywarnings-cxx.m4
-
-Depends-on:
-warnings
-
-configure.ac:
-
-License:
-unlimited
-
-Maintainer:
-Simon Josefsson