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Update configure.ac/Makefile for clang 

Created autoconf/ast_check_raii.m4: contains AST_CHECK_RAII which
checks compiler requirements for RAII:
gcc: -fnested-functions support
clang: -fblocks (and if required -lBlocksRuntime)
The original check was implemented in configure.ac and now has it's
own file. This function also sets C_COMPILER_FAMILY to either gcc or
clang for use by makefile

Created autoconf/ast_check_strsep_array_bounds.m4 (contains
AST_CHECK_STRSEP_ARRAY_BOUNDS):
which checks if clang is able to handle the optimized strsep & strcmp
functions (linux). If not, the standard libc implementation should be
used instead. Clang + the optimized macro's work with:
strsep(char *, char []), but not with strsepo(char *, char *).
Instead of replacing all the occurences throughout the source code,
not using the optimized macro version seemed easier

See 'define __strcmp_gc(s1, s2, l2) in bits/string2.h':
llvm-comment: Normally, this array-bounds warning are suppressed for
macros, so that unused paths like the one that accesses __s1[3] are
not warned about.  But if you preprocess manually, and feed the
result to another instance of clang, it will warn about all the
possible forks of this particular if statement. Instead of switching
of this optimization, another solution would be to run the preproces-
sing step with -frewrite-includes, which should preserve enough
information so that clang should still be able to suppress the diag-
nostic at the compile step later on.

See also "https://llvm.org/bugs/show_bug.cgi?id=20144"
See also "https://llvm.org/bugs/show_bug.cgi?id=11536"

Makefile.rules: If C_COMPILER_FAMILY=clang then add two warning
suppressions:
-Wno-unused-value
-Wno-parentheses-equality
In an earlier review (reviewboard: 4550 and 4554), they were deemed a
nuisace and less than benefitial.

configure.ac:
Added AST_CHECK_RAII() see earlier
Added AST_CHECK_STRSEP_ARRAY_BOUNDS() see earlier
Removed moved content

ASTERISK-24917
Change-Id: I12ea29d3bda2254ad3908e279b7effbbac6a97cb
This commit is contained in:
Diederik de Groot 2015-04-20 20:03:56 +02:00 committed by Matt Jordan
parent 8e1b747284
commit 305ce3defd
7 changed files with 298 additions and 107 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

5
Makefile.rules
View File

@ -65,6 +65,11 @@ endif
CC_CFLAGS=$(PTHREAD_CFLAGS) $(_ASTCFLAGS) $(ASTCFLAGS)
CXX_CFLAGS=$(PTHREAD_CFLAGS) $(filter-out -Wstrict-prototypes -Wmissing-prototypes -Wmissing-declarations $(AST_DECLARATION_AFTER_STATEMENT),$(_ASTCFLAGS) $(ASTCFLAGS))
# Clang -Werror warning suppressions
ifeq ($(C_COMPILER_FAMILY),clang)
CC_CFLAGS+=-Wno-unused-value -Wno-parentheses-equality
endif
ifeq ($(GNU_LD),1)
SO_SUPPRESS_SYMBOLS=-Wl,--version-script,$(subst .so,.exports,$@),--warn-common
ifneq ($(wildcard $(subst .so,.dynamics,$@)),)

56
autoconf/ast_check_raii.m4 Normal file
View File

@ -0,0 +1,56 @@
dnl check RAII requirements
dnl
dnl gcc / llvm-gcc: -fnested-functions
dnl clang : -fblocks / -fblocks and -lBlocksRuntime"
AC_DEFUN([AST_CHECK_RAII], [
AC_MSG_CHECKING([for RAII support])
AST_C_COMPILER_FAMILY=""
AC_LINK_IFELSE(
[AC_LANG_PROGRAM([], [
int main() {
#if defined(__clang__)
choke
#endif
return 0;
}
])
],[
dnl Nested functions required for RAII implementation
AC_MSG_CHECKING(for gcc -fnested-functions)
AC_COMPILE_IFELSE(
dnl Prototype needed due to http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36774
[
AC_LANG_PROGRAM([], [auto void foo(void); void foo(void) {}])
],[
AST_NESTED_FUNCTIONS=""
AC_MSG_RESULT(no)
],[
AST_NESTED_FUNCTIONS="-fnested-functions"
AC_MSG_RESULT(yes)
]
)
AC_SUBST(AST_NESTED_FUNCTIONS)
AST_C_COMPILER_FAMILY="gcc"
],[
AC_MSG_CHECKING(for clang -fblocks)
if test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c - 2>&1`" = ""; then
AST_CLANG_BLOCKS_LIBS=""
AST_CLANG_BLOCKS="-Wno-unknown-warning-option -fblocks"
AC_MSG_RESULT(yes)
elif test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c -lBlocksRuntime - 2>&1`" = ""; then
AST_CLANG_BLOCKS_LIBS="-lBlocksRuntime"
AST_CLANG_BLOCKS="-fblocks"
AC_MSG_RESULT(yes)
else
AC_MSG_ERROR([BlocksRuntime is required for clang, please install libblocksruntime])
fi
AC_SUBST(AST_CLANG_BLOCKS_LIBS)
AC_SUBST(AST_CLANG_BLOCKS)
AST_C_COMPILER_FAMILY="clang"
]
)
if test -z "${AST_C_COMPILER_FAMILY}"; then
AC_MSG_ERROR([Compiler ${CC} not supported. Mminimum required gcc-4.3 / llvm-gcc-4.3 / clang-3.3 + libblocksruntime-dev])
fi
AC_SUBST(AST_C_COMPILER_FAMILY)
])

81
autoconf/ast_check_strsep_array_bounds.m4 Normal file
View File

@ -0,0 +1,81 @@
dnl macro AST_CHECK_STRSEP_ARRAY_BOUNDS0
dnl
dnl The optimized strcmp and strsep macro's in
dnl /usr/include/xxx-linux-gnu/bits/string2.h produce a warning (-Warray-bounds)
dnl when compiled with clang (+ -O1), when the delimiter parameter is
dnl passed in as a char *, instead of the expected char[]
dnl
dnl Instead of replacing all occurrences of strsep and strcmp, looking like:
dnl xxx_name = strsep(&rest, ",");
dnl
dnl with:
dnl char delimiters[] = ",";
dnl xxx_name = strsep(&rest, delimiters);
dnl
dnl to get around this warning, without having to suppress the warning completely.
dnl This macro detects the warning and force these 'optimizations' to be
dnl switched off (Clang already has a set of builtin optimizers which should result
dnl in good performance for these type of functions).
dnl
dnl When the issue is detected it will add a define to autoconfig.h which will prevent
dnl bits/string2.h from replacing the standard implementation of strsep/strcmp with it's
dnl macro optimized version. bits/string.h checks these defines before inserting it's
dnl replacements.
dnl
dnl When bits/string2.h get's fixed in the future, this macro should be able to
dnl detect the new behaviour, and when no warning is generated, it will use the optimize
dnl version from bits/string2.h
dnl
dnl
dnl See 'define __strcmp_gc(s1, s2, l2) in bits/string2.h'
dnl
dnl llvm-comment: Normally, this array-bounds warning are suppressed for macros, so that
dnl unused paths like the one that accesses __s1[3] are not warned about. But if you
dnl preprocess manually, and feed the result to another instance of clang, it will warn
dnl about all the possible forks of this particular if statement.
dnl
dnl Instead of switching of this optimization, another solution would be to run the pre-
dnl processing step with -frewrite-includes, which should preserve enough information
dnl so that clang should still be able to suppress the diagnostic at the compile step
dnl later on.
dnl
dnl See also "https://llvm.org/bugs/show_bug.cgi?id=20144"
dnl See also "https://llvm.org/bugs/show_bug.cgi?id=11536"
dnl
AC_DEFUN([AST_CHECK_STRSEP_ARRAY_BOUNDS], [
AC_MSG_CHECKING([for clang strsep/strcmp optimization])
save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -O1 -Werror=array-bounds"
AC_COMPILE_IFELSE(
[
AC_LANG_SOURCE([
#include <stdio.h>
#include <string.h>
/* fails with clang and -O1 */
void test_strsep_strcmp (void) {
char *haystackstr = "test1,test2";
char *outstr;
if (!strcmp(haystackstr, ",")) {
printf("fail\n");
}
if ((outstr = strsep(&haystackstr, ","))) {
printf("fail:%s\n", outstr);
}
}
int main(int argc, char *argv[]) {
test_strsep_strcmp();
return 0;
}
])
],[
AC_MSG_RESULT(no)
],[
dnl setting this define in autoconfig.h will prevent bits/string2.h from replacing the standard implementation of strsep/strcmp
AC_DEFINE([_HAVE_STRING_ARCH_strcmp], 1, [Prevent clang array-bounds warning by not using strcmp from bits/string2.h])
AC_DEFINE([_HAVE_STRING_ARCH_strsep], 1, [Prevent clang array-bounds warning by not using strsep from bits/string2.h])
AC_MSG_RESULT([prevent use of __string2_1bptr_p / strsep / strcmp from bits/string2.h])
]
)
CFLAGS="$save_CFLAGS"
])

215
configure vendored
View File

@ -687,9 +687,6 @@ PBX_RTLD_NOLOAD
PBX_GLOB_BRACE
PBX_GLOB_NOMAGIC
AST_RPATH
AST_CLANG_BLOCKS
AST_CLANG_BLOCKS_LIBS
AST_NESTED_FUNCTIONS
AST_NATIVE_ARCH
AST_SHADOW_WARNINGS
AST_NO_STRICT_OVERFLOW
@ -1148,6 +1145,10 @@ PBX_ALSA
ALSA_DIR
ALSA_INCLUDE
ALSA_LIB
AST_C_COMPILER_FAMILY
AST_CLANG_BLOCKS
AST_CLANG_BLOCKS_LIBS
AST_NESTED_FUNCTIONS
AST_CODE_COVERAGE
AST_DEVMODE_STRICT
AST_DEVMODE
@ -8227,6 +8228,146 @@ fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for RAII support" >&5
$as_echo_n "checking for RAII support... " >&6; }
AST_C_COMPILER_FAMILY=""
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
int main() {
#if defined(__clang__)
choke
#endif
return 0;
}
;
return 0;
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gcc -fnested-functions" >&5
$as_echo_n "checking for gcc -fnested-functions... " >&6; }
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
auto void foo(void); void foo(void) {}
;
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :
AST_NESTED_FUNCTIONS=""
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
else
AST_NESTED_FUNCTIONS="-fnested-functions"
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
$as_echo "yes" >&6; }
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
AST_C_COMPILER_FAMILY="gcc"
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for clang -fblocks" >&5
$as_echo_n "checking for clang -fblocks... " >&6; }
if test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c - 2>&1`" = ""; then
AST_CLANG_BLOCKS_LIBS=""
AST_CLANG_BLOCKS="-Wno-unknown-warning-option -fblocks"
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
$as_echo "yes" >&6; }
elif test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c -lBlocksRuntime - 2>&1`" = ""; then
AST_CLANG_BLOCKS_LIBS="-lBlocksRuntime"
AST_CLANG_BLOCKS="-fblocks"
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
$as_echo "yes" >&6; }
else
as_fn_error $? "BlocksRuntime is required for clang, please install libblocksruntime" "$LINENO" 5
fi
AST_C_COMPILER_FAMILY="clang"
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
if test -z "${AST_C_COMPILER_FAMILY}"; then
as_fn_error $? "Compiler ${CC} not supported. Mminimum required gcc-4.3 / llvm-gcc-4.3 / clang-3.3 + libblocksruntime-dev" "$LINENO" 5
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for clang strsep/strcmp optimization" >&5
$as_echo_n "checking for clang strsep/strcmp optimization... " >&6; }
save_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS -O1 -Werror=array-bounds"
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
#include <stdio.h>
#include <string.h>
/* fails with clang and -O1 */
void test_strsep_strcmp (void) {
char *haystackstr = "test1,test2";
char *outstr;
if (!strcmp(haystackstr, ",")) {
printf("fail\n");
}
if ((outstr = strsep(&haystackstr, ","))) {
printf("fail:%s\n", outstr);
}
}
int main(int argc, char *argv) {
test_strsep_strcmp();
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
else
$as_echo "#define _HAVE_STRING_ARCH_strcmp 1" >>confdefs.h
$as_echo "#define _HAVE_STRING_ARCH_strsep 1" >>confdefs.h
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: prevent use of __string2_1bptr_p / strsep / strcmp from bits/string2.h" >&5
$as_echo "prevent use of __string2_1bptr_p / strsep / strcmp from bits/string2.h" >&6; }
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
CFLAGS="$save_CFLAGS"
# AST_EXT_LIB_SETUP is used to tell configure to handle variables for
# various packages.
# $1 is the prefix for the variables in makeopts and autoconfig.h
@ -17430,74 +17571,6 @@ $as_echo "no" >&6; }
fi
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
#if defined(__clang__)
choke
#endif
;
return 0;
}
_ACEOF
if ac_fn_c_try_link "$LINENO"; then :
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for gcc -fnested-functions" >&5
$as_echo_n "checking for gcc -fnested-functions... " >&6; }
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
auto void foo(void); void foo(void) {}
;
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
AST_NESTED_FUNCTIONS=
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
$as_echo "yes" >&6; }
AST_NESTED_FUNCTIONS=-fnested-functions
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for clang -fblocks" >&5
$as_echo_n "checking for clang -fblocks... " >&6; }
if test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c - 2>&1`" = ""; then
AST_CLANG_BLOCKS_LIBS=""
AST_CLANG_BLOCKS="-Wno-unknown-warning-option -fblocks"
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
$as_echo "yes" >&6; }
elif test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c -lBlocksRuntime - 2>&1`" = ""; then
AST_CLANG_BLOCKS_LIBS="-lBlocksRuntime"
AST_CLANG_BLOCKS="-fblocks"
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: yes" >&5
$as_echo "yes" >&6; }
else
as_fn_error $? "\"BlocksRuntime is required for clang\"" "$LINENO" 5
fi
fi
rm -f core conftest.err conftest.$ac_objext \
conftest$ac_exeext conftest.$ac_ext
# Check whether --enable-rpath was given.
if test "${enable_rpath+set}" = set; then :

39
configure.ac
View File

@ -386,6 +386,9 @@ AC_ARG_ENABLE([coverage],
esac])
AC_SUBST(AST_CODE_COVERAGE)
AST_CHECK_RAII()
AST_CHECK_STRSEP_ARRAY_BOUNDS()
# AST_EXT_LIB_SETUP is used to tell configure to handle variables for
# various packages.
# $1 is the prefix for the variables in makeopts and autoconfig.h
@ -1134,42 +1137,6 @@ else
fi
AC_SUBST(AST_NATIVE_ARCH)
dnl Nested functions required for RAII implementation
AC_LINK_IFELSE(
[AC_LANG_PROGRAM([], [
#if defined(__clang__)
choke
#endif
])
],[
dnl Nested functions required for RAII implementation
AC_MSG_CHECKING(for gcc -fnested-functions)
AC_COMPILE_IFELSE(
dnl Prototype needed due to http://gcc.gnu.org/bugzilla/show_bug.cgi?id=36774
[AC_LANG_PROGRAM([], [auto void foo(void); void foo(void) {}])],
AC_MSG_RESULT(no)
[AST_NESTED_FUNCTIONS=],
AC_MSG_RESULT(yes)
[AST_NESTED_FUNCTIONS=-fnested-functions]
)
AC_SUBST(AST_NESTED_FUNCTIONS)
],[
AC_MSG_CHECKING(for clang -fblocks)
if test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c - 2>&1`" = ""; then
[AST_CLANG_BLOCKS_LIBS=""]
[AST_CLANG_BLOCKS="-Wno-unknown-warning-option -fblocks"]
AC_MSG_RESULT(yes)
elif test "`echo "int main(){return ^{return 42;}();}" | ${CC} -o /dev/null -fblocks -x c -lBlocksRuntime - 2>&1`" = ""; then
[AST_CLANG_BLOCKS_LIBS="-lBlocksRuntime"]
[AST_CLANG_BLOCKS="-fblocks"]
AC_MSG_RESULT(yes)
else
AC_MSG_ERROR("BlocksRuntime is required for clang")
fi
AC_SUBST(AST_CLANG_BLOCKS_LIBS)
AC_SUBST(AST_CLANG_BLOCKS)
]
)
dnl Check to see if rpath should be set in LDFLAGS
AC_ARG_ENABLE(rpath,

8
include/asterisk/autoconfig.h.in
View File

@ -1314,6 +1314,14 @@
/* Number of bits in a file offset, on hosts where this is settable. */
#undef _FILE_OFFSET_BITS
/* Prevent clang array-bounds warning by not using strcmp from bits/string2.h
*/
#undef _HAVE_STRING_ARCH_strcmp
/* Prevent clang array-bounds warning by not using strsep from bits/string2.h
*/
#undef _HAVE_STRING_ARCH_strsep
/* Define to 1 to make fseeko visible on some hosts (e.g. glibc 2.2). */
#undef _LARGEFILE_SOURCE

1
makeopts.in
View File

@ -111,6 +111,7 @@ AST_SHADOW_WARNINGS=@AST_SHADOW_WARNINGS@
AST_NESTED_FUNCTIONS=@AST_NESTED_FUNCTIONS@
AST_CLANG_BLOCKS=@AST_CLANG_BLOCKS@
AST_CLANG_BLOCKS_LIBS=@AST_CLANG_BLOCKS_LIBS@
C_COMPILER_FAMILY=@AST_C_COMPILER_FAMILY@
AST_RPATH=@AST_RPATH@
AST_FORTIFY_SOURCE=@AST_FORTIFY_SOURCE@
AST_MARCH_NATIVE=@AST_MARCH_NATIVE@