Hello,
I'd like to ask if anyone has any new thoughts on this patch.
Let me also point out that valgrind/memcheck.h is permissively
licensed (BSD-style, rest of Valgrind is GPLv2), with the intention
to allow importing into projects that are interested in using
client requests without build-time dependency on installed headers.
So maybe we have that as an option too.
Alexander
On Fri, 22 Dec 2023, Alexander Monakov wrote:
> From: Daniil Frolov <exactl...@ispras.ru>
>
> PR 66487 is asking to provide sanitizer-like detection for C++ object
> lifetime violations that are worked around with -fno-lifetime-dse or
> -flifetime-dse=1 in Firefox, LLVM (PR 106943), OpenJade (PR 69534).
>
> The discussion in the PR was centered around extending MSan, but MSan
> was not ported to GCC (and requires rebuilding everything with
> instrumentation).
>
> Instead, allow Valgrind to see lifetime boundaries by emitting client
> requests along *this = { CLOBBER }. The client request marks the
> "clobbered" memory as undefined for Valgrind; clobbering assignments
> mark the beginning of ctor and end of dtor execution for C++ objects.
> Hence, attempts to read object storage after the destructor, or
> "pre-initialize" its fields prior to the constructor will be caught.
>
> Valgrind client requests are offered as macros that emit inline asm.
> For use in code generation, let's wrap them as libgcc builtins.
>
> gcc/ChangeLog:
>
> * Makefile.in (OBJS): Add gimple-valgrind-interop.o.
> * builtins.def (BUILT_IN_VALGRIND_MAKE_UNDEFINED): New.
> * common.opt (-fvalgrind-annotations): New option.
> * doc/install.texi (--enable-valgrind-interop): Document.
> * doc/invoke.texi (-fvalgrind-annotations): Document.
> * passes.def (pass_instrument_valgrind): Add.
> * tree-pass.h (make_pass_instrument_valgrind): Declare.
> * gimple-valgrind-interop.cc: New file.
>
> libgcc/ChangeLog:
>
> * Makefile.in (LIB2ADD_ST): Add valgrind-interop.c.
> * config.in: Regenerate.
> * configure: Regenerate.
> * configure.ac (--enable-valgrind-interop): New flag.
> * libgcc2.h (__gcc_vgmc_make_mem_undefined): Declare.
> * valgrind-interop.c: New file.
>
> gcc/testsuite/ChangeLog:
>
> * g++.dg/valgrind-annotations-1.C: New test.
> * g++.dg/valgrind-annotations-2.C: New test.
>
> Co-authored-by: Alexander Monakov <amona...@ispras.ru>
> ---
> Changes in v2:
>
> * Take new clobber kinds into account.
> * Do not link valgrind-interop.o into libgcc_s.so.
>
> gcc/Makefile.in | 1 +
> gcc/builtins.def | 3 +
> gcc/common.opt | 4 +
> gcc/doc/install.texi | 5 +
> gcc/doc/invoke.texi | 27 ++++
> gcc/gimple-valgrind-interop.cc | 125 ++++++++++++++++++
> gcc/passes.def | 1 +
> gcc/testsuite/g++.dg/valgrind-annotations-1.C | 22 +++
> gcc/testsuite/g++.dg/valgrind-annotations-2.C | 12 ++
> gcc/tree-pass.h | 1 +
> libgcc/Makefile.in | 3 +
> libgcc/config.in | 6 +
> libgcc/configure | 22 ++-
> libgcc/configure.ac | 15 ++-
> libgcc/libgcc2.h | 2 +
> libgcc/valgrind-interop.c | 40 ++++++
> 16 files changed, 287 insertions(+), 2 deletions(-)
> create mode 100644 gcc/gimple-valgrind-interop.cc
> create mode 100644 gcc/testsuite/g++.dg/valgrind-annotations-1.C
> create mode 100644 gcc/testsuite/g++.dg/valgrind-annotations-2.C
> create mode 100644 libgcc/valgrind-interop.c
>
> diff --git a/gcc/Makefile.in b/gcc/Makefile.in
> index 9373800018..d027548203 100644
> --- a/gcc/Makefile.in
> +++ b/gcc/Makefile.in
> @@ -1507,6 +1507,7 @@ OBJS = \
> gimple-ssa-warn-restrict.o \
> gimple-streamer-in.o \
> gimple-streamer-out.o \
> + gimple-valgrind-interop.o \
> gimple-walk.o \
> gimple-warn-recursion.o \
> gimplify.o \
> diff --git a/gcc/builtins.def b/gcc/builtins.def
> index f03df32f98..b05e20e062 100644
> --- a/gcc/builtins.def
> +++ b/gcc/builtins.def
> @@ -1194,6 +1194,9 @@ DEF_GCC_BUILTIN (BUILT_IN_LINE, "LINE", BT_FN_INT,
> ATTR_NOTHROW_LEAF_LIST)
> /* Control Flow Redundancy hardening out-of-line checker. */
> DEF_BUILTIN_STUB (BUILT_IN___HARDCFR_CHECK, "__builtin___hardcfr_check")
>
> +/* Wrappers for Valgrind client requests. */
> +DEF_EXT_LIB_BUILTIN (BUILT_IN_VALGRIND_MAKE_UNDEFINED,
> "__gcc_vgmc_make_mem_undefined", BT_FN_VOID_PTR_SIZE, ATTR_NOTHROW_LEAF_LIST)
> +
> /* Synchronization Primitives. */
> #include "sync-builtins.def"
>
> diff --git a/gcc/common.opt b/gcc/common.opt
> index d263a959df..2be5b8d0a6 100644
> --- a/gcc/common.opt
> +++ b/gcc/common.opt
> @@ -3377,6 +3377,10 @@ Enum(auto_init_type) String(pattern)
> Value(AUTO_INIT_PATTERN)
> EnumValue
> Enum(auto_init_type) String(zero) Value(AUTO_INIT_ZERO)
>
> +fvalgrind-annotations
> +Common Var(flag_valgrind_annotations) Optimization
> +Annotate lifetime boundaries with Valgrind client requests.
> +
> ; -fverbose-asm causes extra commentary information to be produced in
> ; the generated assembly code (to make it more readable). This option
> ; is generally only of use to those who actually need to read the
> diff --git a/gcc/doc/install.texi b/gcc/doc/install.texi
> index d20b43a5b2..d6e5e5fdaf 100644
> --- a/gcc/doc/install.texi
> +++ b/gcc/doc/install.texi
> @@ -1563,6 +1563,11 @@ Disable TM clone registry in libgcc. It is enabled in
> libgcc by default.
> This option helps to reduce code size for embedded targets which do
> not use transactional memory.
>
> +@item --enable-valgrind-interop
> +Provide wrappers for Valgrind client requests in libgcc, which are used for
> +@option{-fvalgrind-annotations}. Requires Valgrind header files for the
> +target (in the build-time sysroot if building a cross-compiler).
> +
> @item --with-cpu=@var{cpu}
> @itemx --with-cpu-32=@var{cpu}
> @itemx --with-cpu-64=@var{cpu}
> diff --git a/gcc/doc/invoke.texi b/gcc/doc/invoke.texi
> index d272b9228d..bfbe6a8bd9 100644
> --- a/gcc/doc/invoke.texi
> +++ b/gcc/doc/invoke.texi
> @@ -660,6 +660,7 @@ Objective-C and Objective-C++ Dialects}.
> -fno-stack-limit -fsplit-stack
> -fstrub=disable -fstrub=strict -fstrub=relaxed
> -fstrub=all -fstrub=at-calls -fstrub=internal
> +-fvalgrind-annotations
> -fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]}
> -fvtv-counts -fvtv-debug
> -finstrument-functions -finstrument-functions-once
> @@ -12975,6 +12976,9 @@ can use @option{-flifetime-dse=1}. The default
> behavior can be
> explicitly selected with @option{-flifetime-dse=2}.
> @option{-flifetime-dse=0} is equivalent to @option{-fno-lifetime-dse}.
>
> +See @option{-fvalgrind-annotations} for instrumentation that allows to
> +detect violations of standard lifetime semantics using Valgrind.
> +
> @opindex flive-range-shrinkage
> @item -flive-range-shrinkage
> Attempt to decrease register pressure through register live range
> @@ -18051,6 +18055,29 @@ function attributes that tell which mode was
> selected for each function.
> The primary use of this option is for testing, to exercise thoroughly
> the @code{strub} machinery.
>
> +@opindex fvalgrind-annotations
> +@item -fvalgrind-annotations
> +Emit Valgrind client requests annotating object lifetime boundaries.
> +This allows to detect attempts to access fields of a C++ object after
> +its destructor has completed (but storage was not deallocated yet), or
> +to initialize it in advance from @code{operator new} rather than the
> +constructor.
> +
> +This instrumentation relies on presence of
> @code{__gcc_vgmc_make_mem_undefined}
> +function that wraps the corresponding Valgrind client request. It is provided
> +by libgcc when it is configured with @samp{--enable-valgrind-interop}.
> +Otherwise, you can implement it like this:
> +
> +@smallexample
> +#include <valgrind/memcheck.h>
> +
> +void
> +__gcc_vgmc_make_mem_undefined (void *addr, size_t size)
> +@{
> + VALGRIND_MAKE_MEM_UNDEFINED (addr, size);
> +@}
> +@end smallexample
> +
> @opindex fvtable-verify
> @item -fvtable-verify=@r{[}std@r{|}preinit@r{|}none@r{]}
> This option is only available when compiling C++ code.
> diff --git a/gcc/gimple-valgrind-interop.cc b/gcc/gimple-valgrind-interop.cc
> new file mode 100644
> index 0000000000..05d9bdc660
> --- /dev/null
> +++ b/gcc/gimple-valgrind-interop.cc
> @@ -0,0 +1,125 @@
> +/* Annotate lifetime boundaries for Valgrind.
> + Copyright (C) 2023 Free Software Foundation, Inc.
> +
> +This file is part of GCC.
> +
> +GCC is free software; you can redistribute it and/or modify it
> +under the terms of the GNU General Public License as published by the
> +Free Software Foundation; either version 3, or (at your option) any
> +later version.
> +
> +GCC is distributed in the hope that it will be useful, but WITHOUT
> +ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
> +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
> +for more details.
> +
> +You should have received a copy of the GNU General Public License
> +along with GCC; see the file COPYING3. If not see
> +<http://www.gnu.org/licenses/>. */
> +
> +#include "config.h"
> +#include "system.h"
> +#include "coretypes.h"
> +#include "tree.h"
> +#include "function.h"
> +#include "cfg.h"
> +#include "basic-block.h"
> +#include "gimple.h"
> +#include "gimple-iterator.h"
> +#include "tree-pass.h"
> +#include "gimplify-me.h"
> +#include "fold-const.h"
> +
> +namespace {
> +
> +/* Emit VALGRIND_MAKE_MEM_UNDEFINED annotation for the object given by VAR.
> */
> +
> +bool
> +annotate_undef (gimple_stmt_iterator *gsi, tree var)
> +{
> + tree size = arg_size_in_bytes (TREE_TYPE (var));
> + if (size == size_zero_node)
> + return false;
> +
> + tree addr = build_fold_addr_expr (var);
> + tree decl = builtin_decl_explicit (BUILT_IN_VALGRIND_MAKE_UNDEFINED);
> + tree call = build_call_expr (decl, 2, addr, size);
> +
> + force_gimple_operand_gsi (gsi, call, false, NULL_TREE, false,
> GSI_NEW_STMT);
> + return true;
> +}
> +
> +const pass_data pass_data_instrument_valgrind = {
> + GIMPLE_PASS, /* type */
> + "valgrind", /* name */
> + OPTGROUP_NONE, /* optinfo_flags */
> + TV_NONE, /* tv_id */
> + PROP_cfg, /* properties_required */
> + 0, /* properties_provided */
> + 0, /* properties_destroyed */
> + 0, /* todo_flags_start */
> + 0, /* todo_flags_finish */
> +};
> +
> +}
> +
> +class pass_instrument_valgrind : public gimple_opt_pass
> +{
> +public:
> + pass_instrument_valgrind (gcc::context *ctxt)
> + : gimple_opt_pass (pass_data_instrument_valgrind, ctxt)
> + {
> + }
> +
> + unsigned int execute (function *) final override;
> + bool gate (function *) final override;
> +};
> +
> +bool
> +pass_instrument_valgrind::gate (function *)
> +{
> + return flag_valgrind_annotations;
> +}
> +
> +/* Scan for GIMPLE clobbers that mark object lifetime boundaries and
> + make them known to Valgrind by emitting corresponding client requests. */
> +
> +unsigned int
> +pass_instrument_valgrind::execute (function *fun)
> +{
> + bool changed = false;
> + basic_block bb;
> + FOR_EACH_BB_FN (bb, fun)
> + {
> + for (gimple_stmt_iterator gsi = gsi_start_nondebug_bb (bb);
> + !gsi_end_p (gsi); gsi_next_nondebug (&gsi))
> + {
> + gimple *stmt = gsi_stmt (gsi);
> +
> + if (gimple_clobber_p (stmt))
> + switch (CLOBBER_KIND (gimple_assign_rhs1 (stmt)))
> + {
> + case CLOBBER_UNDEF:
> + case CLOBBER_OBJECT_BEGIN:
> + case CLOBBER_OBJECT_END:
> + changed |= annotate_undef (&gsi, gimple_assign_lhs (stmt));
> + break;
> + case CLOBBER_STORAGE_BEGIN:
> + case CLOBBER_STORAGE_END:
> + /* Leave these for ASan. */
> + break;
> + case CLOBBER_LAST:
> + default:
> + gcc_unreachable ();
> + }
> + }
> + }
> +
> + return changed ? TODO_update_ssa : 0;
> +}
> +
> +gimple_opt_pass *
> +make_pass_instrument_valgrind (gcc::context *ctxt)
> +{
> + return new pass_instrument_valgrind (ctxt);
> +}
> diff --git a/gcc/passes.def b/gcc/passes.def
> index 43b416f98f..2274304321 100644
> --- a/gcc/passes.def
> +++ b/gcc/passes.def
> @@ -57,6 +57,7 @@ along with GCC; see the file COPYING3. If not see
> PUSH_INSERT_PASSES_WITHIN (pass_build_ssa_passes)
> NEXT_PASS (pass_fixup_cfg);
> NEXT_PASS (pass_build_ssa);
> + NEXT_PASS (pass_instrument_valgrind);
> NEXT_PASS (pass_walloca, /*strict_mode_p=*/true);
> NEXT_PASS (pass_warn_printf);
> NEXT_PASS (pass_warn_nonnull_compare);
> diff --git a/gcc/testsuite/g++.dg/valgrind-annotations-1.C
> b/gcc/testsuite/g++.dg/valgrind-annotations-1.C
> new file mode 100644
> index 0000000000..49dc5a9cf1
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/valgrind-annotations-1.C
> @@ -0,0 +1,22 @@
> +/* { dg-do compile { target c++11 } } */
> +/* { dg-options "-O2 -fvalgrind-annotations -fdump-tree-optimized" } */
> +
> +#include <new>
> +
> +struct Foo
> +{
> + int val;
> +};
> +
> +struct Bar : Foo
> +{
> + Bar() {}
> +};
> +
> +int main ()
> +{
> + alignas(Bar) char buf [sizeof (Bar)];
> + Bar *obj = new(buf) Bar;
> +}
> +
> +/* { dg-final { scan-tree-dump-times
> "__builtin___gcc_vgmc_make_mem_undefined" 1 "optimized" } } */
> diff --git a/gcc/testsuite/g++.dg/valgrind-annotations-2.C
> b/gcc/testsuite/g++.dg/valgrind-annotations-2.C
> new file mode 100644
> index 0000000000..a8b646d076
> --- /dev/null
> +++ b/gcc/testsuite/g++.dg/valgrind-annotations-2.C
> @@ -0,0 +1,12 @@
> +/* { dg-do compile { target c++11 } } */
> +/* { dg-options "-O2 -fvalgrind-annotations -fdump-tree-optimized" } */
> +
> +struct Foo
> +{
> + char buf [1024];
> + Foo () {}
> +};
> +
> +Foo Obj;
> +
> +/* { dg-final { scan-tree-dump-times
> "__builtin___gcc_vgmc_make_mem_undefined" 1 "optimized" } } */
> diff --git a/gcc/tree-pass.h b/gcc/tree-pass.h
> index 52fd57fd4c..49de431bd8 100644
> --- a/gcc/tree-pass.h
> +++ b/gcc/tree-pass.h
> @@ -441,6 +441,7 @@ extern gimple_opt_pass *make_pass_omp_device_lower
> (gcc::context *ctxt);
> extern gimple_opt_pass *make_pass_object_sizes (gcc::context *ctxt);
> extern gimple_opt_pass *make_pass_early_object_sizes (gcc::context *ctxt);
> extern gimple_opt_pass *make_pass_warn_access (gcc::context *ctxt);
> +extern gimple_opt_pass *make_pass_instrument_valgrind (gcc::context *ctxt);
> extern gimple_opt_pass *make_pass_warn_printf (gcc::context *ctxt);
> extern gimple_opt_pass *make_pass_warn_recursion (gcc::context *ctxt);
> extern gimple_opt_pass *make_pass_strlen (gcc::context *ctxt);
> diff --git a/libgcc/Makefile.in b/libgcc/Makefile.in
> index 3f77283490..ea3ba705e9 100644
> --- a/libgcc/Makefile.in
> +++ b/libgcc/Makefile.in
> @@ -436,6 +436,9 @@ LIB2ADD += $(srcdir)/hardcfr.c
> # Stack scrubbing infrastructure.
> @HAVE_STRUB_SUPPORT@LIB2ADD += $(srcdir)/strub.c
>
> +# Wrappers for Valgrind client requests.
> +LIB2ADD_ST += $(srcdir)/valgrind-interop.c
> +
> # While emutls.c has nothing to do with EH, it is in LIB2ADDEH*
> # instead of LIB2ADD because that's the way to be sure on some targets
> # (e.g. *-*-darwin*) only one copy of it is linked.
> diff --git a/libgcc/config.in b/libgcc/config.in
> index 8f7dd437b0..a77e9411fc 100644
> --- a/libgcc/config.in
> +++ b/libgcc/config.in
> @@ -3,6 +3,9 @@
> /* Define to the .hidden-like directive if it exists. */
> #undef AS_HIDDEN_DIRECTIVE
>
> +/* Build Valgrind request wrappers */
> +#undef ENABLE_VALGRIND_INTEROP
> +
> /* Define to 1 if the assembler supports AVX. */
> #undef HAVE_AS_AVX
>
> @@ -64,6 +67,9 @@
> /* Define to 1 if you have the <unistd.h> header file. */
> #undef HAVE_UNISTD_H
>
> +/* Define to 1 if you have the <valgrind/memcheck.h> header file. */
> +#undef HAVE_VALGRIND_MEMCHECK_H
> +
> /* Define to 1 if __getauxval is available. */
> #undef HAVE___GETAUXVAL
>
> diff --git a/libgcc/configure b/libgcc/configure
> index 3671d9b1a1..431c028af9 100755
> --- a/libgcc/configure
> +++ b/libgcc/configure
> @@ -716,6 +716,7 @@ with_system_libunwind
> enable_cet
> enable_explicit_exception_frame_registration
> enable_tm_clone_registry
> +enable_valgrind_interop
> with_glibc_version
> enable_tls
> with_gcc_major_version_only
> @@ -1360,6 +1361,8 @@ Optional Features:
> start, for use e.g. for compatibility with
> installations without PT_GNU_EH_FRAME support
> --disable-tm-clone-registry disable TM clone registry
> + --enable-valgrind-interop
> + build wrappers for Valgrind client requests
> --enable-tls Use thread-local storage [default=yes]
>
> Optional Packages:
> @@ -4467,7 +4470,8 @@ as_fn_arith $ac_cv_sizeof_long_double \* 8 &&
> long_double_type_size=$as_val
>
> for ac_header in inttypes.h stdint.h stdlib.h ftw.h \
> unistd.h sys/stat.h sys/types.h \
> - string.h strings.h memory.h sys/auxv.h sys/mman.h
> + string.h strings.h memory.h sys/auxv.h sys/mman.h \
> + valgrind/memcheck.h
> do :
> as_ac_Header=`$as_echo "ac_cv_header_$ac_header" | $as_tr_sh`
> ac_fn_c_check_header_preproc "$LINENO" "$ac_header" "$as_ac_Header"
> @@ -5025,6 +5029,22 @@ fi
>
>
>
> +# Check whether --enable-valgrind-interop was given.
> +if test "${enable_valgrind_interop+set}" = set; then :
> + enableval=$enable_valgrind_interop;
> +else
> + enable_valgrind_interop=no
> +fi
> +
> +if test $enable_valgrind_interop != no; then
> + if test $ac_cv_header_valgrind_memcheck_h = no; then
> + as_fn_error $? "--enable-valgrind-interop: valgrind/memcheck.h not
> found" "$LINENO" 5
> + fi
> +
> +$as_echo "#define ENABLE_VALGRIND_INTEROP 1" >>confdefs.h
> +
> +fi
> +
> { $as_echo "$as_me:${as_lineno-$LINENO}: checking if the linker ($LD) is GNU
> ld" >&5
> $as_echo_n "checking if the linker ($LD) is GNU ld... " >&6; }
> if ${acl_cv_prog_gnu_ld+:} false; then :
> diff --git a/libgcc/configure.ac b/libgcc/configure.ac
> index 467f5e63ef..d19f5e7e84 100644
> --- a/libgcc/configure.ac
> +++ b/libgcc/configure.ac
> @@ -231,7 +231,8 @@ AC_SUBST(long_double_type_size)
>
> AC_CHECK_HEADERS(inttypes.h stdint.h stdlib.h ftw.h \
> unistd.h sys/stat.h sys/types.h \
> - string.h strings.h memory.h sys/auxv.h sys/mman.h)
> + string.h strings.h memory.h sys/auxv.h sys/mman.h \
> + valgrind/memcheck.h)
> AC_HEADER_STDC
>
> # Check for decimal float support.
> @@ -303,6 +304,18 @@ esac
> ])
> AC_SUBST([use_tm_clone_registry])
>
> +AC_ARG_ENABLE([valgrind-interop],
> + [AC_HELP_STRING([--enable-valgrind-interop],
> + [build wrappers for Valgrind client
> requests])],
> + [],
> + [enable_valgrind_interop=no])
> +if test $enable_valgrind_interop != no; then
> + if test $ac_cv_header_valgrind_memcheck_h = no; then
> + AC_MSG_ERROR([--enable-valgrind-interop: valgrind/memcheck.h not found])
> + fi
> + AC_DEFINE(ENABLE_VALGRIND_INTEROP, 1, [Build Valgrind request wrappers])
> +fi
> +
> AC_LIB_PROG_LD_GNU
>
> AC_MSG_CHECKING([for thread model used by GCC])
> diff --git a/libgcc/libgcc2.h b/libgcc/libgcc2.h
> index 750670e8ca..ee4500adc1 100644
> --- a/libgcc/libgcc2.h
> +++ b/libgcc/libgcc2.h
> @@ -558,6 +558,8 @@ extern void __strub_enter (void **);
> extern void __strub_update (void**);
> extern void __strub_leave (void **);
>
> +extern void __gcc_vgmc_make_mem_undefined (void *, size_t);
> +
> #ifndef HIDE_EXPORTS
> #pragma GCC visibility pop
> #endif
> diff --git a/libgcc/valgrind-interop.c b/libgcc/valgrind-interop.c
> new file mode 100644
> index 0000000000..fdb8d41bc5
> --- /dev/null
> +++ b/libgcc/valgrind-interop.c
> @@ -0,0 +1,40 @@
> +/* Wrappers for Valgrind client requests.
> + Copyright (C) 2023 Free Software Foundation, Inc.
> +
> +This file is part of GCC.
> +
> +GCC is free software; you can redistribute it and/or modify it under
> +the terms of the GNU General Public License as published by the Free
> +Software Foundation; either version 3, or (at your option) any later
> +version.
> +
> +GCC is distributed in the hope that it will be useful, but WITHOUT ANY
> +WARRANTY; without even the implied warranty of MERCHANTABILITY or
> +FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
> +for more details.
> +
> +Under Section 7 of GPL version 3, you are granted additional
> +permissions described in the GCC Runtime Library Exception, version
> +3.1, as published by the Free Software Foundation.
> +
> +You should have received a copy of the GNU General Public License and
> +a copy of the GCC Runtime Library Exception along with this program;
> +see the files COPYING3 and COPYING.RUNTIME respectively. If not, see
> +<http://www.gnu.org/licenses/>. */
> +
> +#include "tsystem.h"
> +#include "auto-target.h"
> +
> +#ifdef ENABLE_VALGRIND_INTEROP
> +
> +#include <valgrind/memcheck.h>
> +
> +/* Externally callable wrapper for Valgrind Memcheck client request:
> + declare SIZE bytes of memory at address ADDR as uninitialized. */
> +
> +void
> +__gcc_vgmc_make_mem_undefined (void *addr, size_t size)
> +{
> + VALGRIND_MAKE_MEM_UNDEFINED (addr, size);
> +}
> +#endif
>
