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Re: [PATCH v2 10/10] Add --enable-ubsan
>>>>> "Tom" == Tom Tromey <tom@tromey.com> writes:
Tom> It was in GCC 4.9. It is tested at configure time. I've updated the
Tom> text & will send a new patch.
Let me know what you think.
Tom
commit fcb215b14cfe9e45178659b94fa9978c5b457bb8
Author: Tom Tromey <tom@tromey.com>
Date: Sat Aug 18 15:32:46 2018 -0600
Add --enable-ubsan
This adds --enable-ubsan to gdb's configure. By default it is enabled
in development mode, and disabled otherwise. This passes both
-fsanitize=undefined and -fno-sanitize-recover=undefined to
compilations, so that undefined behavior violations will be sure to
cause test failures.
gdb/ChangeLog
2018-10-01 Tom Tromey <tom@tromey.com>
* README: Mention --enable-ubsan.
* NEWS: Mention --enable-ubsan.
* acinclude.m4: Include sanitize.m4.
* configure: Rebuild.
* configure.ac: Call AM_GDB_UBSAN.
* sanitize.m4: New file.
gdb/doc/ChangeLog
2018-10-01 Tom Tromey <tom@tromey.com>
* gdb.texinfo (Configure Options): Document --enable-ubsan.
diff --git a/gdb/ChangeLog b/gdb/ChangeLog
index 2776263e86..451f7c4f67 100644
--- a/gdb/ChangeLog
+++ b/gdb/ChangeLog
@@ -1,3 +1,12 @@
+2018-10-01 Tom Tromey <tom@tromey.com>
+
+ * README: Mention --enable-ubsan.
+ * NEWS: Mention --enable-ubsan.
+ * acinclude.m4: Include sanitize.m4.
+ * configure: Rebuild.
+ * configure.ac: Call AM_GDB_UBSAN.
+ * sanitize.m4: New file.
+
2018-10-01 Tom Tromey <tom@tromey.com>
* expression.h (enum exp_opcode): Use uint8_t as base type.
diff --git a/gdb/NEWS b/gdb/NEWS
index 00adcd4d53..b409aa447c 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -108,6 +108,16 @@ CSKY GNU/LINUX csky*-*-linux
** The gdb.Progspace type has a new 'objfiles' method, which returns the list
of objfiles associated to that program space.
+* Configure changes
+
+--enable-ubsan
+
+ Enable or disable the undefined behavior sanitizer. Release
+ versions of GDB disable this by default if it is available, but
+ development versions enable it. Enabling this can cause a
+ performance penalty. The undefined behavior sanitizer was first
+ introduced in GCC 4.9.
+
*** Changes in GDB 8.2
* The 'set disassembler-options' command now supports specifying options
diff --git a/gdb/README b/gdb/README
index 5881be23af..69ba0eb8df 100644
--- a/gdb/README
+++ b/gdb/README
@@ -538,6 +538,13 @@ more obscure GDB `configure' options are not listed here.
the compiler, which will fail the compilation if the compiler
outputs any warning messages.
+`--enable-ubsan'
+ Enable the GCC undefined behavior sanitizer. By default this is
+ disabled in GDB releases, but enabled when building from git.
+ The undefined behavior sanitizer checks for C++ undefined
+ behavior. It has a performance cost, so if you are looking at
+ GDB's performance, you should disable it.
+
`configure' accepts other options, for compatibility with configuring
other GNU tools recursively.
diff --git a/gdb/acinclude.m4 b/gdb/acinclude.m4
index 3c2d01015b..52ba3f9ed6 100644
--- a/gdb/acinclude.m4
+++ b/gdb/acinclude.m4
@@ -15,6 +15,9 @@ sinclude(transform.m4)
# This gets AM_GDB_WARNINGS.
sinclude(warning.m4)
+# AM_GDB_UBSAN
+sinclude(sanitize.m4)
+
dnl gdb/configure.in uses BFD_NEED_DECLARATION, so get its definition.
sinclude(../bfd/bfd.m4)
diff --git a/gdb/configure b/gdb/configure
index 931e19d2a4..0ba80147c6 100755
--- a/gdb/configure
+++ b/gdb/configure
@@ -886,6 +886,7 @@ with_system_gdbinit
enable_werror
enable_build_warnings
enable_gdb_build_warnings
+enable_ubsan
with_lzma
with_liblzma_prefix
with_tcl
@@ -1556,6 +1557,7 @@ Optional Features:
--enable-gdb-build-warnings
enable GDB specific build-time compiler warnings if
gcc is used
+ --enable-ubsan enable undefined behavior sanitizer (auto/yes/no)
--enable-sim link gdb with simulator
--enable-gdbserver automatically build gdbserver (yes/no/auto, default
is auto)
@@ -2448,6 +2450,52 @@ $as_echo "$ac_res" >&6; }
eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
} # ac_fn_c_check_decl
+
+# ac_fn_cxx_try_link LINENO
+# -------------------------
+# Try to link conftest.$ac_ext, and return whether this succeeded.
+ac_fn_cxx_try_link ()
+{
+ as_lineno=${as_lineno-"$1"} as_lineno_stack=as_lineno_stack=$as_lineno_stack
+ rm -f conftest.$ac_objext conftest$ac_exeext
+ if { { ac_try="$ac_link"
+case "(($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_link") 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$ac_exeext && {
+ test "$cross_compiling" = yes ||
+ test -x conftest$ac_exeext
+ }; then :
+ ac_retval=0
+else
+ $as_echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+ ac_retval=1
+fi
+ # Delete the IPA/IPO (Inter Procedural Analysis/Optimization) information
+ # created by the PGI compiler (conftest_ipa8_conftest.oo), as it would
+ # interfere with the next link command; also delete a directory that is
+ # left behind by Apple's compiler. We do this before executing the actions.
+ rm -rf conftest.dSYM conftest_ipa8_conftest.oo
+ eval $as_lineno_stack; ${as_lineno_stack:+:} unset as_lineno
+ as_fn_set_status $ac_retval
+
+} # ac_fn_cxx_try_link
cat >config.log <<_ACEOF
This file contains any messages produced by compilers while
running configure, to aid debugging if configure makes a mistake.
@@ -15561,6 +15609,63 @@ ac_compiler_gnu=$ac_cv_c_compiler_gnu
+# Check whether --enable-ubsan was given.
+if test "${enable_ubsan+set}" = set; then :
+ enableval=$enable_ubsan;
+else
+ enable_ubsan=auto
+fi
+
+if test "x$enable_ubsan" = xauto; then
+ if $development; then
+ enable_ubsan=yes
+ fi
+fi
+ac_ext=cpp
+ac_cpp='$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 "x$enable_ubsan" = xyes; then
+ { $as_echo "$as_me:${as_lineno-$LINENO}: checking whether -fsanitize=undefined is accepted" >&5
+$as_echo_n "checking whether -fsanitize=undefined is accepted... " >&6; }
+ saved_CXXFLAGS="$CXXFLAGS"
+ CXXFLAGS="$CXXFLAGS -fsanitize=undefined -fno-sanitize-recover=undefined"
+ cat confdefs.h - <<_ACEOF >conftest.$ac_ext
+/* end confdefs.h. */
+
+int
+main ()
+{
+
+ ;
+ return 0;
+}
+_ACEOF
+if ac_fn_cxx_try_link "$LINENO"; then :
+ enable_ubsan=yes
+else
+ enable_ubsan=no
+fi
+rm -f core conftest.err conftest.$ac_objext \
+ conftest$ac_exeext conftest.$ac_ext
+ CXXFLAGS="$saved_CXXFLAGS"
+ { $as_echo "$as_me:${as_lineno-$LINENO}: result: $enable_ubsan" >&5
+$as_echo "$enable_ubsan" >&6; }
+ if test "x$enable_ubsan" = xyes; then
+ WARN_CFLAGS="$WARN_CFLAGS -fsanitize=undefined -fno-sanitize-recover=undefined"
+ CONFIG_LDFLAGS="$CONFIG_LDFLAGS -fsanitize=undefined"
+ 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
+
+
+
# In the Cygwin environment, we need some additional flags.
{ $as_echo "$as_me:${as_lineno-$LINENO}: checking for cygwin" >&5
$as_echo_n "checking for cygwin... " >&6; }
diff --git a/gdb/configure.ac b/gdb/configure.ac
index 88f2fc47e1..dfb7c87171 100644
--- a/gdb/configure.ac
+++ b/gdb/configure.ac
@@ -1838,6 +1838,7 @@ GDB_AC_WITH_DIR(SYSTEM_GDBINIT, system-gdbinit,
[])
AM_GDB_WARNINGS
+AM_GDB_UBSAN
# In the Cygwin environment, we need some additional flags.
AC_CACHE_CHECK([for cygwin], gdb_cv_os_cygwin,
diff --git a/gdb/doc/ChangeLog b/gdb/doc/ChangeLog
index c26b8e6e91..76b654a043 100644
--- a/gdb/doc/ChangeLog
+++ b/gdb/doc/ChangeLog
@@ -1,3 +1,7 @@
+2018-10-01 Tom Tromey <tom@tromey.com>
+
+ * gdb.texinfo (Configure Options): Document --enable-ubsan.
+
2018-10-02 John Darrington <john@darrington.wattle.id.au>
* gdb.texinfo (Remote Connection Commands): Describe
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index d37c9e43ca..5653bdcaca 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -35763,6 +35763,14 @@ compiler you are using.
Treat compiler warnings as werrors. It adds the @code{-Werror} flag
to the compiler, which will fail the compilation if the compiler
outputs any warning messages.
+
+@item --enable-ubsan
+Enable the GCC undefined behavior sanitizer. By default this is
+disabled in @value{GDBN} releases, but enabled, when available, when
+building from git. The undefined behavior sanitizer checks for
+C@t{++} undefined behavior. It has a performance cost, so if you are
+looking at @value{GDBN}'s performance, you should disable it. The
+undefined behavior sanitizer was first introduced in GCC 4.9.
@end table
@node System-wide configuration
diff --git a/gdb/sanitize.m4 b/gdb/sanitize.m4
new file mode 100644
index 0000000000..3e2207b466
--- /dev/null
+++ b/gdb/sanitize.m4
@@ -0,0 +1,46 @@
+dnl Autoconf configure script for GDB, the GNU debugger.
+dnl Copyright (C) 2018 Free Software Foundation, Inc.
+dnl
+dnl This file is part of GDB.
+dnl
+dnl This program is free software; you can redistribute it and/or modify
+dnl it under the terms of the GNU General Public License as published by
+dnl the Free Software Foundation; either version 3 of the License, or
+dnl (at your option) any later version.
+dnl
+dnl This program is distributed in the hope that it will be useful,
+dnl but WITHOUT ANY WARRANTY; without even the implied warranty of
+dnl MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+dnl GNU General Public License for more details.
+dnl
+dnl You should have received a copy of the GNU General Public License
+dnl along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+AC_DEFUN([AM_GDB_UBSAN],[
+AC_ARG_ENABLE(ubsan,
+ AS_HELP_STRING([--enable-ubsan],
+ [enable undefined behavior sanitizer (auto/yes/no)]),
+ [],enable_ubsan=auto)
+if test "x$enable_ubsan" = xauto; then
+ if $development; then
+ enable_ubsan=yes
+ fi
+fi
+AC_LANG_PUSH([C++])
+if test "x$enable_ubsan" = xyes; then
+ AC_MSG_CHECKING(whether -fsanitize=undefined is accepted)
+ saved_CXXFLAGS="$CXXFLAGS"
+ CXXFLAGS="$CXXFLAGS -fsanitize=undefined -fno-sanitize-recover=undefined"
+ dnl A link check is required because it is possible to install gcc
+ dnl without libubsan, leading to link failures when compiling with
+ dnl -fsanitize=undefined.
+ AC_TRY_LINK([],[],enable_ubsan=yes,enable_ubsan=no)
+ CXXFLAGS="$saved_CXXFLAGS"
+ AC_MSG_RESULT($enable_ubsan)
+ if test "x$enable_ubsan" = xyes; then
+ WARN_CFLAGS="$WARN_CFLAGS -fsanitize=undefined -fno-sanitize-recover=undefined"
+ CONFIG_LDFLAGS="$CONFIG_LDFLAGS -fsanitize=undefined"
+ fi
+fi
+AC_LANG_POP([C++])
+])