delete trailing whitespace from control files
[debian/gzip] / m4 / manywarnings.m4
index 844a9ba2a07213fe89d135faef8448a225b618ce..d831ed2eb60ab537a446c18e20a54a421e4fb015 100644 (file)
@@ -1,5 +1,5 @@
-# manywarnings.m4 serial 1
-dnl Copyright (C) 2008, 2009, 2010 Free Software Foundation, Inc.
+# manywarnings.m4 serial 17
+dnl Copyright (C) 2008-2018 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.
@@ -30,79 +30,305 @@ AC_DEFUN([gl_MANYWARN_COMPLEMENT],
 
 # gl_MANYWARN_ALL_GCC(VARIABLE)
 # -----------------------------
-# Add all documented GCC (currently as per version 4.4) 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.
+# 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.
+#
+# The effects of this macro depend on the current language (_AC_LANG).
 AC_DEFUN([gl_MANYWARN_ALL_GCC],
+[_AC_LANG_DISPATCH([$0], _AC_LANG, $@)])
+
+# Specialization for _AC_LANG = C.
+# Use of m4_defun rather than AC_DEFUN works around a bug in autoconf < 2.63b.
+m4_defun([gl_MANYWARN_ALL_GCC(C)],
 [
- gl_manywarn_set=
- for gl_manywarn_item in \
-   -Wall \
-   -W \
-   -Wformat-y2k \
-   -Wformat-nonliteral \
-   -Wformat-security \
-   -Winit-self \
-   -Wmissing-include-dirs \
-   -Wswitch-default \
-   -Wswitch-enum \
-   -Wunused \
-   -Wunknown-pragmas \
-   -Wstrict-aliasing \
-   -Wstrict-overflow \
-   -Wsystem-headers \
-   -Wfloat-equal \
-   -Wtraditional \
-   -Wtraditional-conversion \
-   -Wdeclaration-after-statement \
-   -Wundef \
-   -Wshadow \
-   -Wunsafe-loop-optimizations \
-   -Wpointer-arith \
-   -Wbad-function-cast \
-   -Wc++-compat \
-   -Wcast-qual \
-   -Wcast-align \
-   -Wwrite-strings \
-   -Wconversion \
-   -Wsign-conversion \
-   -Wlogical-op \
-   -Waggregate-return \
-   -Wstrict-prototypes \
-   -Wold-style-definition \
-   -Wmissing-prototypes \
-   -Wmissing-declarations \
-   -Wmissing-noreturn \
-   -Wmissing-format-attribute \
-   -Wpacked \
-   -Wpadded \
-   -Wredundant-decls \
-   -Wnested-externs \
-   -Wunreachable-code \
-   -Winline \
-   -Winvalid-pch \
-   -Wlong-long \
-   -Wvla \
-   -Wvolatile-register-var \
-   -Wdisabled-optimization \
-   -Wstack-protector \
-   -Woverlength-strings \
-   -Wbuiltin-macro-redefined \
-   -Wmudflap \
-   -Wpacked-bitfield-compat \
-   -Wsync-nand \
-  ; do
-    gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item"
-  done
- # The following are not documented in the manual but are included in
- # output from gcc --help=warnings.
- for gl_manywarn_item in \
-   -Wattributes \
-   -Wcoverage-mismatch \
-   -Wmultichar \
-   -Wunused-macros \
-  ; do
+  AC_LANG_PUSH([C])
+
+  dnl First, check for some issues that only occur when combining multiple
+  dnl gcc warning categories.
+  AC_REQUIRE([AC_PROG_CC])
+  if test -n "$GCC"; then
+
+    dnl Check if -W -Werror -Wno-missing-field-initializers is supported
+    dnl with the current $CC $CFLAGS $CPPFLAGS.
+    AC_CACHE_CHECK([whether -Wno-missing-field-initializers is supported],
+      [gl_cv_cc_nomfi_supported],
+      [gl_save_CFLAGS="$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"
+      ])
+
+    if test "$gl_cv_cc_nomfi_supported" = yes; then
+      dnl Now check whether -Wno-missing-field-initializers is needed
+      dnl for the { 0, } construct.
+      AC_CACHE_CHECK([whether -Wno-missing-field-initializers is needed],
+        [gl_cv_cc_nomfi_needed],
+        [gl_save_CFLAGS="$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"
+        ])
+    fi
+
+    dnl Next, check if -Werror -Wuninitialized is useful with the
+    dnl user's choice of $CFLAGS; some versions of gcc warn that it
+    dnl has no effect if -O is not also used
+    AC_CACHE_CHECK([whether -Wuninitialized is supported],
+      [gl_cv_cc_uninitialized_supported],
+      [gl_save_CFLAGS="$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"
+      ])
+
+  fi
+
+  # List all gcc warning categories.
+  # To compare this list to your installed GCC's, run this Bash command:
+  #
+  # comm -3 \
+  #  <((sed -n 's/^  *\(-[^ 0-9][^ ]*\) .*/\1/p' manywarnings.m4; \
+  #     awk '/^[^#]/ {print $1}' ../build-aux/gcc-warning.spec) | sort) \
+  #  <(LC_ALL=C gcc --help=warnings | sed -n 's/^  \(-[^ ]*\) .*/\1/p' | sort)
+
+  gl_manywarn_set=
+  for gl_manywarn_item in -fno-common \
+    -W \
+    -Waddress \
+    -Waggressive-loop-optimizations \
+    -Wall \
+    -Wattribute-alias \
+    -Wattributes \
+    -Wbad-function-cast \
+    -Wbool-compare \
+    -Wbool-operation \
+    -Wbuiltin-declaration-mismatch \
+    -Wbuiltin-macro-redefined \
+    -Wcast-align \
+    -Wcast-align=strict \
+    -Wcast-function-type \
+    -Wchar-subscripts \
+    -Wclobbered \
+    -Wcomment \
+    -Wcomments \
+    -Wcoverage-mismatch \
+    -Wcpp \
+    -Wdangling-else \
+    -Wdate-time \
+    -Wdeprecated \
+    -Wdeprecated-declarations \
+    -Wdesignated-init \
+    -Wdisabled-optimization \
+    -Wdiscarded-array-qualifiers \
+    -Wdiscarded-qualifiers \
+    -Wdiv-by-zero \
+    -Wdouble-promotion \
+    -Wduplicated-branches \
+    -Wduplicated-cond \
+    -Wduplicate-decl-specifier \
+    -Wempty-body \
+    -Wendif-labels \
+    -Wenum-compare \
+    -Wexpansion-to-defined \
+    -Wextra \
+    -Wformat-contains-nul \
+    -Wformat-extra-args \
+    -Wformat-nonliteral \
+    -Wformat-security \
+    -Wformat-signedness \
+    -Wformat-y2k \
+    -Wformat-zero-length \
+    -Wframe-address \
+    -Wfree-nonheap-object \
+    -Whsa \
+    -Wif-not-aligned \
+    -Wignored-attributes \
+    -Wignored-qualifiers \
+    -Wimplicit \
+    -Wimplicit-function-declaration \
+    -Wimplicit-int \
+    -Wincompatible-pointer-types \
+    -Winit-self \
+    -Winline \
+    -Wint-conversion \
+    -Wint-in-bool-context \
+    -Wint-to-pointer-cast \
+    -Winvalid-memory-model \
+    -Winvalid-pch \
+    -Wlogical-not-parentheses \
+    -Wlogical-op \
+    -Wmain \
+    -Wmaybe-uninitialized \
+    -Wmemset-elt-size \
+    -Wmemset-transposed-args \
+    -Wmisleading-indentation \
+    -Wmissing-attributes \
+    -Wmissing-braces \
+    -Wmissing-declarations \
+    -Wmissing-field-initializers \
+    -Wmissing-include-dirs \
+    -Wmissing-parameter-type \
+    -Wmissing-prototypes \
+    -Wmultichar \
+    -Wmultistatement-macros \
+    -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 \
+    -Wpacked-not-aligned \
+    -Wparentheses \
+    -Wpointer-arith \
+    -Wpointer-compare \
+    -Wpointer-sign \
+    -Wpointer-to-int-cast \
+    -Wpragmas \
+    -Wpsabi \
+    -Wrestrict \
+    -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-div \
+    -Wsizeof-pointer-memaccess \
+    -Wstack-protector \
+    -Wstrict-aliasing \
+    -Wstrict-overflow \
+    -Wstrict-prototypes \
+    -Wstringop-truncation \
+    -Wsuggest-attribute=cold \
+    -Wsuggest-attribute=const \
+    -Wsuggest-attribute=format \
+    -Wsuggest-attribute=malloc \
+    -Wsuggest-attribute=noreturn \
+    -Wsuggest-attribute=pure \
+    -Wsuggest-final-methods \
+    -Wsuggest-final-types \
+    -Wswitch \
+    -Wswitch-bool \
+    -Wswitch-unreachable \
+    -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.
+  # Would prefer "min (PTRDIFF_MAX, SIZE_MAX)", but it must be a literal.
+  # Also, AC_COMPUTE_INT requires it to fit in a long; it is 2**63 on
+  # the only platforms where it does not fit in a long, so make that
+  # a special case.
+  AC_MSG_CHECKING([max safe object size])
+  AC_COMPUTE_INT([gl_alloc_max],
+    [LONG_MAX < (PTRDIFF_MAX < (size_t) -1 ? PTRDIFF_MAX : (size_t) -1)
+     ? -1
+     : PTRDIFF_MAX < (size_t) -1 ? (long) PTRDIFF_MAX : (long) (size_t) -1],
+    [[#include <limits.h>
+      #include <stddef.h>
+      #include <stdint.h>
+    ]],
+    [gl_alloc_max=2147483647])
+  case $gl_alloc_max in
+    -1) gl_alloc_max=9223372036854775807;;
+  esac
+  AC_MSG_RESULT([$gl_alloc_max])
+  gl_manywarn_set="$gl_manywarn_set -Walloc-size-larger-than=$gl_alloc_max"
+  gl_manywarn_set="$gl_manywarn_set -Warray-bounds=2"
+  gl_manywarn_set="$gl_manywarn_set -Wformat-overflow=2"
+  gl_manywarn_set="$gl_manywarn_set -Wformat-truncation=2"
+  gl_manywarn_set="$gl_manywarn_set -Wimplicit-fallthrough=5"
+  gl_manywarn_set="$gl_manywarn_set -Wnormalized=nfc"
+  gl_manywarn_set="$gl_manywarn_set -Wshift-overflow=2"
+  gl_manywarn_set="$gl_manywarn_set -Wstringop-overflow=2"
+  gl_manywarn_set="$gl_manywarn_set -Wunused-const-variable=2"
+  gl_manywarn_set="$gl_manywarn_set -Wvla-larger-than=4031"
+
+  # These are needed for older GCC versions.
+  if test -n "$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
+
+  AC_LANG_POP([C])
+])
+
+# Specialization for _AC_LANG = C++.
+# Use of m4_defun rather than AC_DEFUN works around a bug in autoconf < 2.63b.
+m4_defun([gl_MANYWARN_ALL_GCC(C++)],
+[
+  gl_MANYWARN_ALL_GCC_CXX_IMPL([$1])
 ])