Add --enable-build-with-cxx configure switch

This new option, disabled by default for now, allows specifying
whether to build GDB, GDBserver, and friends with a C++ (98/03)
compiler.

The name of the switch should be familiar to those who followed GCC's
own C++ conversion process.

. Adding -fpermissive to COMPILER in C++ mode (see the new
build-with-cxx.m4 file) makes errors like these be warnings instead:

  gdb/infrun.c:6597:1: error:   initializing argument 1 of ‘void sig_print_info(gdb_signal)’ [-fpermissive]
   sig_print_info (enum gdb_signal oursig)
   ^
  gdb/infrun.c: In function ‘void do_restore_infcall_suspend_state_cleanup(void*)’:
  gdb/infrun.c:7164:39: error: invalid conversion from ‘void*’ to ‘infcall_suspend_state*’ [-fpermissive]
     restore_infcall_suspend_state (state);
				 ^

so that the compiler carries on compiling the file.  -Werror still
catches the warnings, so nothing is lost, only our lifes are made
easier by concentrating on getting other more important things out of
the way first.

There's no way to quiet those warnings.  Until they're all fixed, when
building in C++ mode, -Werror is disabled by default.

. Adding -Wno-narrowing suppresses thousands of instances of this warning:

  gdb/arm-linux-tdep.c:439:1: error: narrowing conversion of ‘-1’ from ‘int’ to ‘ULONGEST {aka long unsigned int}’ inside { } is ill-formed in C++11 [-Werror=narrowing]
  gdb/arm-linux-tdep.c:439:1: error: narrowing conversion of ‘-1l’ from ‘LONGEST {aka long int}’ to ‘ULONGEST {aka long unsigned int}’ inside { } is ill-formed in C++11 [-Werror=narrowing]
  gdb/arm-linux-tdep.c:450:1: error: narrowing conversion of ‘-1’ from ‘int’ to ‘ULONGEST {aka long unsigned int}’ inside { } is ill-formed in C++11 [-Werror=narrowing]

We can defer handling those until we target C++11.


. Adding -Wno-sign-compare suppresses thousands of instances of this warning:

  gdb/linux-record.c:1763:32: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
	 if (tmpulongest == tdep->fcntl_F_GETLK64)
				  ^


. Adding -Wno-write-strings suppresses thousands of instances of this warning:

  gdb/mi/mi-cmd-var.c: In function ‘void mi_cmd_var_show_attributes(char*, char**, int)’:
  gdb/mi/mi-cmd-var.c:514:12: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
       attstr = "editable";
	      ^
  gdb/mi/mi-cmd-var.c:516:12: warning: deprecated conversion from string constant to ‘char*’ [-Wwrite-strings]
       attstr = "noneditable";
	      ^

For now, it's best to hide these warnings from view until we're
'-fpermissive'-clean, and can thus start building with -Werror.
The C compiler has always managed to build working GDBs with these
issues in the code, so a C++ compiler should too.

gdb/ChangeLog:
2015-02-27  Pedro Alves  <palves@redhat.com>

	* Makefile.in (COMPILER): New, get it from autoconf.
	(COMPILE.pre, CC_LD): Use COMPILER.
	(CXX): Get from autoconf instead.
	(CXX_FOR_TARGET): Default to g++ instead of gcc.
	* acinclude.m4: Include build-with-cxx.m4.
	* build-with-cxx.m4: New file.
	* configure.ac: Call AC_PROG_CXX and GDB_AC_BUILD_WITH_CXX.
	Disable -Werror by default if building in C++ mode.
	(build_warnings): Add -Wno-sign-compare, -Wno-write-strings and
	-Wno-narrowing in C++ mode.  Only enable -Wpointer-sign in C mode.
	Run supported-warning-flags tests with the C++ compiler.
	Save/restore CXXFLAGS too.
	* configure: Regenerate.

gdb/gdbserver/ChangeLog:
2015-02-27  Pedro Alves  <palves@redhat.com>

	* Makefile.in (COMPILER): New, get it from autoconf.
	(CXX): Get from autoconf instead.
	(COMPILE.pre): Use COMPILER.
	(CC-LD): Rename to ...
	(CC_LD): ... this.  Use COMPILER.
	(gdbserver$(EXEEXT), gdbreplay$(EXEEXT), $(IPA_LIB)): Adjust.
	(CXX_FOR_TARGET): Default to g++ instead of gcc.
	* acinclude.m4: Include build-with-cxx.m4.
	* configure.ac: Call AC_PROG_CXX and GDB_AC_BUILD_WITH_CXX.
	Disable -Werror by default if building in C++ mode.
	(build_warnings): Add -Wno-sign-compare, -Wno-write-strings and
	-Wno-narrowing in C++ mode. Run supported-warning-flags tests with
	the C++ compiler.  Save/restore CXXFLAGS too.
	* configure: Regenerate.
This commit is contained in:
Pedro Alves
2015-02-27 13:11:25 +00:00
parent f0673d2040
commit 3bc3d82a00
11 changed files with 908 additions and 31 deletions

View File

@@ -615,6 +615,7 @@ DEPDIR
am__leading_dot
host_noncanonical
target_noncanonical
COMPILER
RANLIB
AR
INSTALL_DATA
@@ -635,6 +636,9 @@ build
EGREP
GREP
CPP
ac_ct_CXX
CXXFLAGS
CXX
OBJEXT
EXEEXT
ac_ct_CC
@@ -688,6 +692,7 @@ ac_user_opts='
enable_option_checking
enable_maintainer_mode
enable_largefile
enable_build_with_cxx
enable_libmcheck
with_ust
with_ust_include
@@ -706,6 +711,9 @@ CFLAGS
LDFLAGS
LIBS
CPPFLAGS
CXX
CXXFLAGS
CCC
CPP'
@@ -1328,6 +1336,7 @@ Optional Features:
--enable-maintainer-mode enable make rules and dependencies not useful
(and sometimes confusing) to the casual installer
--disable-largefile omit support for large files
--enable-build-with-cxx build with C++ compiler instead of C compiler
--enable-libmcheck Try linking with -lmcheck if available
--enable-werror treat compile warnings as errors
--enable-inprocess-agent
@@ -1354,6 +1363,8 @@ Some influential environment variables:
LIBS libraries to pass to the linker, e.g. -l<library>
CPPFLAGS C/C++/Objective C preprocessor flags, e.g. -I<include dir> if
you have headers in a nonstandard directory <include dir>
CXX C++ compiler command
CXXFLAGS C++ compiler flags
CPP C preprocessor
Use these variables to override the choices made by `configure' or to help
@@ -1474,6 +1485,44 @@ fi
} # ac_fn_c_try_compile
# ac_fn_cxx_try_compile LINENO
# ----------------------------
# Try to compile conftest.$ac_ext, and return whether this succeeded.
ac_fn_cxx_try_compile ()
{
as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
rm -f conftest.$ac_objext
if { { ac_try="$ac_compile"
case "(($ac_try" in
*\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
*) ac_try_echo=$ac_try;;
esac
eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
$as_echo "$ac_try_echo"; } >&5
(eval "$ac_compile") 2>conftest.err
ac_status=$?
if test -s conftest.err; then
grep -v '^ *+' conftest.err >conftest.er1
cat conftest.er1 >&5
mv -f conftest.er1 conftest.err
fi
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; } && {
test -z "$ac_cxx_werror_flag" ||
test ! -s conftest.err
} && test -s conftest.$ac_objext; then :
ac_retval=0
else
$as_echo "$as_me: failed program was:" >&5
sed 's/^/| /' conftest.$ac_ext >&5
ac_retval=1
fi
eval $as_lineno_stack; test "x$as_lineno_stack" = x && { as_lineno=; unset as_lineno;}
return $ac_retval
} # ac_fn_cxx_try_compile
# ac_fn_c_try_cpp LINENO
# ----------------------
# Try to preprocess conftest.$ac_ext, and return whether this succeeded.
@@ -3206,6 +3255,263 @@ ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
ac_compiler_gnu=$ac_cv_c_compiler_gnu
ac_ext=cpp
ac_cpp='$CXXCPP $CPPFLAGS'
ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
if test -z "$CXX"; then
if test -n "$CCC"; then
CXX=$CCC
else
if test -n "$ac_tool_prefix"; then
for ac_prog in g++ c++ gpp aCC CC cxx cc++ cl.exe FCC KCC RCC xlC_r xlC
do
# Extract the first word of "$ac_tool_prefix$ac_prog", so it can be a program name with args.
set dummy $ac_tool_prefix$ac_prog; ac_word=$2
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
$as_echo_n "checking for $ac_word... " >&6; }
if test "${ac_cv_prog_CXX+set}" = set; then :
$as_echo_n "(cached) " >&6
else
if test -n "$CXX"; then
ac_cv_prog_CXX="$CXX" # Let the user override the test.
else
as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
for as_dir in $PATH
do
IFS=$as_save_IFS
test -z "$as_dir" && as_dir=.
for ac_exec_ext in '' $ac_executable_extensions; do
if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
ac_cv_prog_CXX="$ac_tool_prefix$ac_prog"
$as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
break 2
fi
done
done
IFS=$as_save_IFS
fi
fi
CXX=$ac_cv_prog_CXX
if test -n "$CXX"; then
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $CXX" >&5
$as_echo "$CXX" >&6; }
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
fi
test -n "$CXX" && break
done
fi
if test -z "$CXX"; then
ac_ct_CXX=$CXX
for ac_prog in g++ c++ gpp aCC CC cxx cc++ cl.exe FCC KCC RCC xlC_r xlC
do
# Extract the first word of "$ac_prog", so it can be a program name with args.
set dummy $ac_prog; ac_word=$2
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for $ac_word" >&5
$as_echo_n "checking for $ac_word... " >&6; }
if test "${ac_cv_prog_ac_ct_CXX+set}" = set; then :
$as_echo_n "(cached) " >&6
else
if test -n "$ac_ct_CXX"; then
ac_cv_prog_ac_ct_CXX="$ac_ct_CXX" # Let the user override the test.
else
as_save_IFS=$IFS; IFS=$PATH_SEPARATOR
for as_dir in $PATH
do
IFS=$as_save_IFS
test -z "$as_dir" && as_dir=.
for ac_exec_ext in '' $ac_executable_extensions; do
if { test -f "$as_dir/$ac_word$ac_exec_ext" && $as_test_x "$as_dir/$ac_word$ac_exec_ext"; }; then
ac_cv_prog_ac_ct_CXX="$ac_prog"
$as_echo "$as_me:${as_lineno-$LINENO}: found $as_dir/$ac_word$ac_exec_ext" >&5
break 2
fi
done
done
IFS=$as_save_IFS
fi
fi
ac_ct_CXX=$ac_cv_prog_ac_ct_CXX
if test -n "$ac_ct_CXX"; then
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_ct_CXX" >&5
$as_echo "$ac_ct_CXX" >&6; }
else
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: no" >&5
$as_echo "no" >&6; }
fi
test -n "$ac_ct_CXX" && break
done
if test "x$ac_ct_CXX" = x; then
CXX="g++"
else
case $cross_compiling:$ac_tool_warned in
yes:)
{ $as_echo "$as_me:${as_lineno-$LINENO}: WARNING: using cross tools not prefixed with host triplet" >&5
$as_echo "$as_me: WARNING: using cross tools not prefixed with host triplet" >&2;}
ac_tool_warned=yes ;;
esac
CXX=$ac_ct_CXX
fi
fi
fi
fi
# Provide some information about the compiler.
$as_echo "$as_me:${as_lineno-$LINENO}: checking for C++ compiler version" >&5
set X $ac_compile
ac_compiler=$2
for ac_option in --version -v -V -qversion; do
{ { ac_try="$ac_compiler $ac_option >&5"
case "(($ac_try" in
*\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
*) ac_try_echo=$ac_try;;
esac
eval ac_try_echo="\"\$as_me:${as_lineno-$LINENO}: $ac_try_echo\""
$as_echo "$ac_try_echo"; } >&5
(eval "$ac_compiler $ac_option >&5") 2>conftest.err
ac_status=$?
if test -s conftest.err; then
sed '10a\
... rest of stderr output deleted ...
10q' conftest.err >conftest.er1
cat conftest.er1 >&5
rm -f conftest.er1 conftest.err
fi
$as_echo "$as_me:${as_lineno-$LINENO}: \$? = $ac_status" >&5
test $ac_status = 0; }
done
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether we are using the GNU C++ compiler" >&5
$as_echo_n "checking whether we are using the GNU C++ compiler... " >&6; }
if test "${ac_cv_cxx_compiler_gnu+set}" = set; then :
$as_echo_n "(cached) " >&6
else
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
#ifndef __GNUC__
choke me
#endif
;
return 0;
}
_ACEOF
if ac_fn_cxx_try_compile "$LINENO"; then :
ac_compiler_gnu=yes
else
ac_compiler_gnu=no
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
ac_cv_cxx_compiler_gnu=$ac_compiler_gnu
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_cxx_compiler_gnu" >&5
$as_echo "$ac_cv_cxx_compiler_gnu" >&6; }
if test $ac_compiler_gnu = yes; then
GXX=yes
else
GXX=
fi
ac_test_CXXFLAGS=${CXXFLAGS+set}
ac_save_CXXFLAGS=$CXXFLAGS
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking whether $CXX accepts -g" >&5
$as_echo_n "checking whether $CXX accepts -g... " >&6; }
if test "${ac_cv_prog_cxx_g+set}" = set; then :
$as_echo_n "(cached) " >&6
else
ac_save_cxx_werror_flag=$ac_cxx_werror_flag
ac_cxx_werror_flag=yes
ac_cv_prog_cxx_g=no
CXXFLAGS="-g"
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
;
return 0;
}
_ACEOF
if ac_fn_cxx_try_compile "$LINENO"; then :
ac_cv_prog_cxx_g=yes
else
CXXFLAGS=""
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
;
return 0;
}
_ACEOF
if ac_fn_cxx_try_compile "$LINENO"; then :
else
ac_cxx_werror_flag=$ac_save_cxx_werror_flag
CXXFLAGS="-g"
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
main ()
{
;
return 0;
}
_ACEOF
if ac_fn_cxx_try_compile "$LINENO"; then :
ac_cv_prog_cxx_g=yes
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
ac_cxx_werror_flag=$ac_save_cxx_werror_flag
fi
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: $ac_cv_prog_cxx_g" >&5
$as_echo "$ac_cv_prog_cxx_g" >&6; }
if test "$ac_test_CXXFLAGS" = set; then
CXXFLAGS=$ac_save_CXXFLAGS
elif test $ac_cv_prog_cxx_g = yes; then
if test "$GXX" = yes; then
CXXFLAGS="-g -O2"
else
CXXFLAGS="-g"
fi
else
if test "$GXX" = yes; then
CXXFLAGS="-O2"
else
CXXFLAGS=
fi
fi
ac_ext=c
ac_cpp='$CPP $CPPFLAGS'
ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
ac_compiler_gnu=$ac_cv_c_compiler_gnu
ac_ext=c
ac_cpp='$CPP $CPPFLAGS'
@@ -4403,6 +4709,30 @@ $as_echo "#define STDC_HEADERS 1" >>confdefs.h
fi
# See if we are building with C++, and substitute COMPILER.
# Check whether --enable-build-with-cxx was given.
if test "${enable_build_with_cxx+set}" = set; then :
enableval=$enable_build_with_cxx; case $enableval in
yes | no)
;;
*)
as_fn_error "bad value $enableval for --enable-build-with-cxx" "$LINENO" 5 ;;
esac
else
enable_build_with_cxx=no
fi
if test "$enable_build_with_cxx" = "yes"; then
# We're using -fpermissive as shortcut for now.
COMPILER='$(CXX) -fpermissive'
else
COMPILER='$(CC)'
fi
# Set the 'development' global.
. $srcdir/../../bfd/development.sh
@@ -5451,8 +5781,11 @@ if test "${enable_werror+set}" = set; then :
fi
# Enable -Werror by default when using gcc. Turn it off for releases.
if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" && $development; then
# Enable -Werror by default when using gcc in C mode. Leave it off
# for C++ until we're warning clean. Turn it off for releases.
if test "${GCC}" = yes -a -z "${ERROR_ON_WARNING}" \
&& test x"$enable_build_with_cxx" != x"yes" \
&& $development; then
ERROR_ON_WARNING=yes
fi
@@ -5464,6 +5797,23 @@ fi
build_warnings="-Wall -Wdeclaration-after-statement -Wpointer-arith \
-Wformat-nonliteral -Wno-char-subscripts -Wempty-body"
# Now add in C and C++ specific options, depending on mode.
if test "$enable_build_with_cxx" = "yes"; then
build_warnings="$build_warnings -Wno-sign-compare -Wno-write-strings \
-Wno-narrowing"
fi
# The set of warnings supported by a C++ compiler is not the same as
# of the C compiler.
if test "$enable_build_with_cxx" = "yes"; then
ac_ext=cpp
ac_cpp='$CXXCPP $CPPFLAGS'
ac_compile='$CXX -c $CXXFLAGS $CPPFLAGS conftest.$ac_ext >&5'
ac_link='$CXX -o conftest$ac_exeext $CXXFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
ac_compiler_gnu=$ac_cv_cxx_compiler_gnu
fi
WARN_CFLAGS=""
if test "x$GCC" = xyes
then
@@ -5474,10 +5824,14 @@ $as_echo_n "checking compiler warning flags... " >&6; }
for w in ${build_warnings}; do
case $w in
-Werr*) WERROR_CFLAGS=-Werror ;;
*) # Check that GCC accepts it
*)
# Check whether GCC accepts it.
saved_CFLAGS="$CFLAGS"
CFLAGS="$CFLAGS $w"
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
saved_CXXFLAGS="$CXXFLAGS"
CXXFLAGS="$CXXFLAGS $w"
cat confdefs.h - <<_ACEOF >conftest.$ac_ext
/* end confdefs.h. */
int
@@ -5488,11 +5842,12 @@ main ()
return 0;
}
_ACEOF
if ac_fn_c_try_compile "$LINENO"; then :
if ac_fn_cxx_try_compile "$LINENO"; then :
WARN_CFLAGS="${WARN_CFLAGS} $w"
fi
rm -f core conftest.err conftest.$ac_objext conftest.$ac_ext
CFLAGS="$saved_CFLAGS"
CXXFLAGS="$saved_CXXFLAGS"
esac
done
{ $as_echo "$as_me:${as_lineno-$LINENO}: result: ${WARN_CFLAGS} ${WERROR_CFLAGS}" >&5
@@ -5501,6 +5856,15 @@ fi
if test "$enable_build_with_cxx" = "yes"; then
ac_ext=c
ac_cpp='$CPP $CPPFLAGS'
ac_compile='$CC -c $CFLAGS $CPPFLAGS conftest.$ac_ext >&5'
ac_link='$CC -o conftest$ac_exeext $CFLAGS $CPPFLAGS $LDFLAGS conftest.$ac_ext $LIBS >&5'
ac_compiler_gnu=$ac_cv_c_compiler_gnu
fi
old_LIBS="$LIBS"
LIBS="$LIBS -ldl"
for ac_func in dladdr