1# manywarnings.m4 serial 7
2dnl Copyright (C) 2008-2014 Free Software Foundation, Inc.
3dnl This file is free software; the Free Software Foundation
4dnl gives unlimited permission to copy and/or distribute it,
5dnl with or without modifications, as long as this notice is preserved.
6
7dnl From Simon Josefsson
8
9# gl_MANYWARN_COMPLEMENT(OUTVAR, LISTVAR, REMOVEVAR)
10# --------------------------------------------------
11# Copy LISTVAR to OUTVAR except for the entries in REMOVEVAR.
12# Elements separated by whitespace.  In set logic terms, the function
13# does OUTVAR = LISTVAR \ REMOVEVAR.
14AC_DEFUN([gl_MANYWARN_COMPLEMENT],
15[
16  gl_warn_set=
17  set x $2; shift
18  for gl_warn_item
19  do
20    case " $3 " in
21      *" $gl_warn_item "*)
22        ;;
23      *)
24        gl_warn_set="$gl_warn_set $gl_warn_item"
25        ;;
26    esac
27  done
28  $1=$gl_warn_set
29])
30
31# gl_MANYWARN_ALL_GCC(VARIABLE)
32# -----------------------------
33# Add all documented GCC warning parameters to variable VARIABLE.
34# Note that you need to test them using gl_WARN_ADD if you want to
35# make sure your gcc understands it.
36AC_DEFUN([gl_MANYWARN_ALL_GCC],
37[
38  dnl First, check for some issues that only occur when combining multiple
39  dnl gcc warning categories.
40  AC_REQUIRE([AC_PROG_CC])
41  if test -n "$GCC"; then
42
43    dnl Check if -W -Werror -Wno-missing-field-initializers is supported
44    dnl with the current $CC $CFLAGS $CPPFLAGS.
45    AC_MSG_CHECKING([whether -Wno-missing-field-initializers is supported])
46    AC_CACHE_VAL([gl_cv_cc_nomfi_supported], [
47      gl_save_CFLAGS="$CFLAGS"
48      CFLAGS="$CFLAGS -W -Werror -Wno-missing-field-initializers"
49      AC_COMPILE_IFELSE(
50        [AC_LANG_PROGRAM([[]], [[]])],
51        [gl_cv_cc_nomfi_supported=yes],
52        [gl_cv_cc_nomfi_supported=no])
53      CFLAGS="$gl_save_CFLAGS"])
54    AC_MSG_RESULT([$gl_cv_cc_nomfi_supported])
55
56    if test "$gl_cv_cc_nomfi_supported" = yes; then
57      dnl Now check whether -Wno-missing-field-initializers is needed
58      dnl for the { 0, } construct.
59      AC_MSG_CHECKING([whether -Wno-missing-field-initializers is needed])
60      AC_CACHE_VAL([gl_cv_cc_nomfi_needed], [
61        gl_save_CFLAGS="$CFLAGS"
62        CFLAGS="$CFLAGS -W -Werror"
63        AC_COMPILE_IFELSE(
64          [AC_LANG_PROGRAM(
65             [[void f (void)
66               {
67                 typedef struct { int a; int b; } s_t;
68                 s_t s1 = { 0, };
69               }
70             ]],
71             [[]])],
72          [gl_cv_cc_nomfi_needed=no],
73          [gl_cv_cc_nomfi_needed=yes])
74        CFLAGS="$gl_save_CFLAGS"
75      ])
76      AC_MSG_RESULT([$gl_cv_cc_nomfi_needed])
77    fi
78
79    dnl Next, check if -Werror -Wuninitialized is useful with the
80    dnl user's choice of $CFLAGS; some versions of gcc warn that it
81    dnl has no effect if -O is not also used
82    AC_MSG_CHECKING([whether -Wuninitialized is supported])
83    AC_CACHE_VAL([gl_cv_cc_uninitialized_supported], [
84      gl_save_CFLAGS="$CFLAGS"
85      CFLAGS="$CFLAGS -Werror -Wuninitialized"
86      AC_COMPILE_IFELSE(
87        [AC_LANG_PROGRAM([[]], [[]])],
88        [gl_cv_cc_uninitialized_supported=yes],
89        [gl_cv_cc_uninitialized_supported=no])
90      CFLAGS="$gl_save_CFLAGS"])
91    AC_MSG_RESULT([$gl_cv_cc_uninitialized_supported])
92
93  fi
94
95  # List all gcc warning categories.
96  # To compare this list to your installed GCC's, run this Bash command:
97  #
98  # comm -3 \
99  #  <(sed -n 's/^  *\(-[^ ]*\) .*/\1/p' manywarnings.m4 | sort) \
100  #  <(gcc --help=warnings | sed -n 's/^  \(-[^ ]*\) .*/\1/p' | sort |
101  #      grep -v -x -f <(
102  #         awk '/^[^#]/ {print $1}' ../build-aux/gcc-warning.spec))
103
104  gl_manywarn_set=
105  for gl_manywarn_item in \
106    -W \
107    -Wabi \
108    -Waddress \
109    -Waggressive-loop-optimizations \
110    -Wall \
111    -Warray-bounds \
112    -Wattributes \
113    -Wbad-function-cast \
114    -Wbuiltin-macro-redefined \
115    -Wcast-align \
116    -Wchar-subscripts \
117    -Wclobbered \
118    -Wcomment \
119    -Wcomments \
120    -Wcoverage-mismatch \
121    -Wcpp \
122    -Wdate-time \
123    -Wdeprecated \
124    -Wdeprecated-declarations \
125    -Wdisabled-optimization \
126    -Wdiv-by-zero \
127    -Wdouble-promotion \
128    -Wempty-body \
129    -Wendif-labels \
130    -Wenum-compare \
131    -Wextra \
132    -Wformat-contains-nul \
133    -Wformat-extra-args \
134    -Wformat-nonliteral \
135    -Wformat-security \
136    -Wformat-y2k \
137    -Wformat-zero-length \
138    -Wfree-nonheap-object \
139    -Wignored-qualifiers \
140    -Wimplicit \
141    -Wimplicit-function-declaration \
142    -Wimplicit-int \
143    -Winit-self \
144    -Winline \
145    -Wint-to-pointer-cast \
146    -Winvalid-memory-model \
147    -Winvalid-pch \
148    -Wjump-misses-init \
149    -Wlogical-op \
150    -Wmain \
151    -Wmaybe-uninitialized \
152    -Wmissing-braces \
153    -Wmissing-declarations \
154    -Wmissing-field-initializers \
155    -Wmissing-include-dirs \
156    -Wmissing-parameter-type \
157    -Wmissing-prototypes \
158    -Wmultichar \
159    -Wnarrowing \
160    -Wnested-externs \
161    -Wnonnull \
162    -Wold-style-declaration \
163    -Wold-style-definition \
164    -Wopenmp-simd \
165    -Woverflow \
166    -Woverlength-strings \
167    -Woverride-init \
168    -Wpacked \
169    -Wpacked-bitfield-compat \
170    -Wparentheses \
171    -Wpointer-arith \
172    -Wpointer-sign \
173    -Wpointer-to-int-cast \
174    -Wpragmas \
175    -Wreturn-local-addr \
176    -Wreturn-type \
177    -Wsequence-point \
178    -Wshadow \
179    -Wsizeof-pointer-memaccess \
180    -Wstack-protector \
181    -Wstrict-aliasing \
182    -Wstrict-overflow \
183    -Wstrict-prototypes \
184    -Wsuggest-attribute=const \
185    -Wsuggest-attribute=format \
186    -Wsuggest-attribute=noreturn \
187    -Wsuggest-attribute=pure \
188    -Wswitch \
189    -Wswitch-default \
190    -Wsync-nand \
191    -Wsystem-headers \
192    -Wtrampolines \
193    -Wtrigraphs \
194    -Wtype-limits \
195    -Wuninitialized \
196    -Wunknown-pragmas \
197    -Wunsafe-loop-optimizations \
198    -Wunused \
199    -Wunused-but-set-parameter \
200    -Wunused-but-set-variable \
201    -Wunused-function \
202    -Wunused-label \
203    -Wunused-local-typedefs \
204    -Wunused-macros \
205    -Wunused-parameter \
206    -Wunused-result \
207    -Wunused-value \
208    -Wunused-variable \
209    -Wvarargs \
210    -Wvariadic-macros \
211    -Wvector-operation-performance \
212    -Wvla \
213    -Wvolatile-register-var \
214    -Wwrite-strings \
215    \
216    ; do
217    gl_manywarn_set="$gl_manywarn_set $gl_manywarn_item"
218  done
219
220  # gcc --help=warnings outputs an unusual form for this option; list
221  # it here so that the above 'comm' command doesn't report a false match.
222  gl_manywarn_set="$gl_manywarn_set -Wnormalized=nfc"
223
224  # These are needed for older GCC versions.
225  if test -n "$GCC"; then
226    case `($CC --version) 2>/dev/null` in
227      'gcc (GCC) '[[0-3]].* | \
228      'gcc (GCC) '4.[[0-7]].*)
229        gl_manywarn_set="$gl_manywarn_set -fdiagnostics-show-option"
230        gl_manywarn_set="$gl_manywarn_set -funit-at-a-time"
231          ;;
232    esac
233  fi
234
235  # Disable specific options as needed.
236  if test "$gl_cv_cc_nomfi_needed" = yes; then
237    gl_manywarn_set="$gl_manywarn_set -Wno-missing-field-initializers"
238  fi
239
240  if test "$gl_cv_cc_uninitialized_supported" = no; then
241    gl_manywarn_set="$gl_manywarn_set -Wno-uninitialized"
242  fi
243
244  $1=$gl_manywarn_set
245])
246