1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
|
AC_DEFUN([_NM_COMPILER_FLAG], [
CFLAGS_SAVED="$CFLAGS"
CFLAGS="$CFLAGS $GLIB_CFLAGS -Werror $1"
AC_MSG_CHECKING([whether $1 works as expected])
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[]])], [
AC_COMPILE_IFELSE([AC_LANG_SOURCE([[$2]])], [
AC_MSG_RESULT(yes)
CFLAGS="$CFLAGS_SAVED"
$3
],[
AC_MSG_RESULT(no)
CFLAGS="$CFLAGS_SAVED"
$4
])
],[
AC_MSG_RESULT(not supported)
CFLAGS="$CFLAGS_SAVED"
])
])
dnl Check whether a particular compiler flag is supported,
dnl add it to CFLAGS if it is
AC_DEFUN([NM_COMPILER_FLAG], [
_NM_COMPILER_FLAG([$1], [], [
CFLAGS="$CFLAGS $1"
$2
], [$3])
])
dnl Check whether a particular warning is not emitted with code provided,
dnl disable it in CFLAGS if the check fails.
AC_DEFUN([NM_COMPILER_WARNING], [
_NM_COMPILER_FLAG([-W$1], [$2], [CFLAGS="$CFLAGS -W$1"], [CFLAGS="$CFLAGS -Wno-$1"])
])
AC_DEFUN([NM_COMPILER_WARNINGS],
[AC_ARG_ENABLE(more-warnings,
AS_HELP_STRING([--enable-more-warnings], [Possible values: no/yes/error]),
set_more_warnings="$enableval",set_more_warnings=$1)
AC_MSG_CHECKING(for more warnings)
if test "$GCC" = "yes" -a "$set_more_warnings" != "no"; then
AC_MSG_RESULT(yes)
dnl This is enabled in clang by default, makes little sense,
dnl and causes the build to abort with -Werror.
CFLAGS_SAVED="$CFLAGS"
CFLAGS="$CFLAGS -Qunused-arguments"
AC_COMPILE_IFELSE([AC_LANG_SOURCE([])], [], CFLAGS="$CFLAGS_SAVED")
unset CFLAGS_SAVED
dnl clang only warns about unknown warnings, unless
dnl called with "-Werror=unknown-warning-option"
dnl Test if the compiler supports that, and if it does
dnl attach it to the CFLAGS.
NM_COMPILER_WARNING([unknown-warning-option], [])
CFLAGS_MORE_WARNINGS="-Wall -std=gnu99"
if test "x$set_more_warnings" = xerror; then
CFLAGS_MORE_WARNINGS="$CFLAGS_MORE_WARNINGS -Werror"
fi
for option in \
-Wextra \
-Wdeclaration-after-statement \
-Wfloat-equal \
-Wformat-nonliteral \
-Wformat-security \
-Wimplicit-fallthrough \
-Wimplicit-function-declaration \
-Winit-self \
-Wlogical-op \
-Wmissing-declarations \
-Wmissing-include-dirs \
-Wmissing-prototypes \
-Wpointer-arith \
-Wshadow \
-Wshift-negative-value \
-Wstrict-prototypes \
-Wundef \
-Wno-duplicate-decl-specifier \
-Wno-format-truncation \
-Wno-format-y2k \
-Wno-missing-field-initializers \
-Wno-pragmas \
-Wno-sign-compare \
-Wno-unused-but-set-variable \
-Wno-unused-parameter \
; do
dnl GCC 4.4 does not warn when checking for -Wno-* flags (https://gcc.gnu.org/wiki/FAQ#wnowarning)
_NM_COMPILER_FLAG([$(printf '%s' "$option" | sed 's/^-Wno-/-W/')], [],
[CFLAGS_MORE_WARNINGS="$CFLAGS_MORE_WARNINGS $option"], [])
done
unset option
dnl Disable warnings triggered by known compiler problems
dnl https://bugzilla.gnome.org/show_bug.cgi?id=745821
NM_COMPILER_WARNING([unknown-attributes], [#include <glib.h>])
dnl https://bugzilla.gnome.org/show_bug.cgi?id=744473
NM_COMPILER_WARNING([typedef-redefinition], [#include <gio/gio.h>])
dnl https://llvm.org/bugs/show_bug.cgi?id=21614
NM_COMPILER_WARNING([array-bounds],
[#include <string.h>]
[void f () { strcmp ("something", "0"); }]
)
dnl https://llvm.org/bugs/show_bug.cgi?id=22949
NM_COMPILER_WARNING([parentheses-equality],
[#include <sys/wait.h>]
[void f () { if (WIFCONTINUED(0)) return; }]
)
dnl systemd-dhcp's log_internal macro and our handle_warn are sometimes
dnl used in void context,u sometimes in int. Makes clang unhappy.
NM_COMPILER_WARNING([unused-value],
[#define yolo ({ (666 + 666); })]
[int f () { int i = yolo; yolo; return i; }]
)
dnl clang 3.9 would like to see "{ { 0 } }" here, but that does not
dnl look too wise.
NM_COMPILER_WARNING([missing-braces],
[union { int a[1]; int b[2]; } c = { 0 }]
)
CFLAGS="$CFLAGS_MORE_WARNINGS $CFLAGS"
else
AC_MSG_RESULT(no)
fi
])
AC_DEFUN([NM_LTO],
[AC_ARG_ENABLE(lto, AS_HELP_STRING([--enable-lto], [Enable Link Time Optimization for smaller size (default: no)]))
if (test "${enable_lto}" = "yes"); then
CC_CHECK_FLAG_APPEND([lto_flags], [CFLAGS], [-flto])
if (test -n "${lto_flags}"); then
CFLAGS="-flto $CFLAGS"
else
AC_MSG_ERROR([Link Time Optimization -flto is not supported.])
fi
else
enable_lto='no'
fi
])
AC_DEFUN([NM_LD_GC],
[AC_ARG_ENABLE(ld-gc, AS_HELP_STRING([--enable-ld-gc], [Enable garbage collection of unused symbols on linking (default: auto)]))
if (test "${enable_ld_gc}" != "no"); then
CC_CHECK_FLAG_APPEND([ld_gc_flags], [CFLAGS], [-fdata-sections -ffunction-sections -Wl,--gc-sections])
if (test -n "${ld_gc_flags}"); then
enable_ld_gc="yes"
CFLAGS="$ld_gc_flags $CFLAGS"
else
if (test "${enable_ld_gc}" = "yes"); then
AC_MSG_ERROR([Unused symbol eviction requested but not supported.])
else
enable_ld_gc="no"
fi
fi
fi
])
|
