commit 4831385c6706b377851284adc4c4545fff4c6564

Author: Nicholas Nethercote <nnethercote@apple.com>

Date:   Tue Nov 9 12:30:07 2021 +1100

    Fix Rust v0 demangling.

    It's currently broken due to a silly test that prevents the v0

    demangling code from even running.

    The commit also adds a test, to avoid such problems in the future.

diff --git a/coregrind/m_demangle/demangle.c b/coregrind/m_demangle/demangle.c

index 16161da2a..3fd7cb75f 100644

--- a/coregrind/m_demangle/demangle.c

+++ b/coregrind/m_demangle/demangle.c

@@ -118,8 +118,13 @@ void VG_(demangle) ( Bool do_cxx_demangling, Bool do_z_demangling,

    }

    /* Possibly undo (1) */

+   // - C++ mangled symbols start with "_Z" (possibly with exceptions?)

+   // - Rust "legacy" mangled symbols start with "_Z".

+   // - Rust "v0" mangled symbols start with "_R".

+   // XXX: the Java/Rust/Ada demangling here probably doesn't work. See

+   // https://bugs.kde.org/show_bug.cgi?id=445235 for details.

    if (do_cxx_demangling && VG_(clo_demangle)

-       && orig != NULL && orig[0] == '_' && orig[1] == 'Z') {

+       && orig != NULL && orig[0] == '_' && (orig[1] == 'Z' || orig[1] == 'R')) {

       /* !!! vvv STATIC vvv !!! */

       static HChar* demangled = NULL;

       /* !!! ^^^ STATIC ^^^ !!! */

diff --git a/memcheck/tests/demangle-rust.c b/memcheck/tests/demangle-rust.c

new file mode 100644

index 000000000..f2a458b2a

--- /dev/null

+++ b/memcheck/tests/demangle-rust.c

@@ -0,0 +1,31 @@

+// Valgrind supports demangling Rust symbols (both the "v0" and "legacy"

+// mangling schemes), but we don't want to add a dependency on the Rust

+// compiler for a single test. So this is a C program with function names that

+// are mangled Rust symbols. In the output, they become demangled Rust names.

+// It's a hack, but a useful one.

+

+#include <stdlib.h>

+

+// A v0 symbol that demangles to: <rustc_middle::ty::PredicateKind as rustc_middle::ty::fold::TypeFoldable>::fold_with::<rustc_infer::infer::resolve::OpportunisticVarResolver>

+int _RINvYNtNtCs4uGc65yWeeX_12rustc_middle2ty13PredicateKindNtNtB5_4fold12TypeFoldable9fold_withNtNtNtCsgI90OQiJWEs_11rustc_infer5infer7resolve24OpportunisticVarResolverECsdozMG8X9FIu_21rustc_trait_selection(int *p)

+{

+   return *p ? 1 : 2;

+}

+

+// A v0 symbol that demangles to: rustc_expand::mbe::macro_parser::parse_tt

+int _RNvNtNtCsaqSe1lZGvEL_12rustc_expand3mbe12macro_parser8parse_tt(int* p)

+{

+   return _RINvYNtNtCs4uGc65yWeeX_12rustc_middle2ty13PredicateKindNtNtB5_4fold12TypeFoldable9fold_withNtNtNtCsgI90OQiJWEs_11rustc_infer5infer7resolve24OpportunisticVarResolverECsdozMG8X9FIu_21rustc_trait_selection(p);

+}

+

+// A legacy symbol that demangles to: core::str::lossy::Utf8Lossy::from_bytes

+int _ZN4core3str5lossy9Utf8Lossy10from_bytes17heb1677c8cb728b0bE(int* p)

+{

+   return _RNvNtNtCsaqSe1lZGvEL_12rustc_expand3mbe12macro_parser8parse_tt(p);

+}

+

+int main(void)

+{

+   return _ZN4core3str5lossy9Utf8Lossy10from_bytes17heb1677c8cb728b0bE(malloc(sizeof(int)));

+}

+

diff --git a/memcheck/tests/demangle-rust.stderr.exp b/memcheck/tests/demangle-rust.stderr.exp

new file mode 100644

index 000000000..f04bb625b

--- /dev/null

+++ b/memcheck/tests/demangle-rust.stderr.exp

@@ -0,0 +1,6 @@

+Conditional jump or move depends on uninitialised value(s)

+   at 0x........: <rustc_middle::ty::PredicateKind as rustc_middle::ty::fold::TypeFoldable>::fold_with::<rustc_infer::infer::resolve::OpportunisticVarResolver> (demangle-rust.c:12)

+   by 0x........: rustc_expand::mbe::macro_parser::parse_tt (demangle-rust.c:18)

+   by 0x........: core::str::lossy::Utf8Lossy::from_bytes (demangle-rust.c:24)

+   by 0x........: main (demangle-rust.c:29)

+

diff --git a/memcheck/tests/demangle-rust.vgtest b/memcheck/tests/demangle-rust.vgtest

new file mode 100644

index 000000000..d726c6b2e

--- /dev/null

+++ b/memcheck/tests/demangle-rust.vgtest

@@ -0,0 +1,2 @@

+prog: demangle-rust

+vgopts: -q

commit c1bfa115f985633722f25922d2996c231e8c9d8d

Author: Mark Wielaard <mark@klomp.org>

Date:   Wed Nov 10 09:02:36 2021 +0100

    Add demangle-rust.vgtest demangle-rust.stderr.exp to EXTRA_DIST

diff --git a/memcheck/tests/Makefile.am b/memcheck/tests/Makefile.am

index 4d0476e2d..7837d87c7 100644

--- a/memcheck/tests/Makefile.am

+++ b/memcheck/tests/Makefile.am

@@ -281,6 +281,7 @@ EXTRA_DIST = \

 	realloc3.stderr.exp realloc3.vgtest \

 	recursive-merge.stderr.exp recursive-merge.vgtest \

 	resvn_stack.stderr.exp resvn_stack.vgtest \

+	demangle-rust.vgtest demangle-rust.stderr.exp \

 	sbfragment.stdout.exp sbfragment.stderr.exp sbfragment.vgtest \

 	sem.stderr.exp sem.vgtest \

 	sendmsg.stderr.exp sendmsg.stderr.exp-solaris sendmsg.vgtest \

commit d151907e5d8ff393f4fef126c8ae445ea8813661

Author: Mark Wielaard <mark@klomp.org>

Date:   Thu Nov 11 18:02:09 2021 +0100

    Add demangle-rust to check_PROGRAMS

    The demangle-rust.vgtest would fail because the demangle-rust binary

    wasn't build by default. Add it to check_PROGRAMS and define

    demangle_rust_SOURCES to make sure it is always build.

diff --git a/memcheck/tests/Makefile.am b/memcheck/tests/Makefile.am

index 7837d87c7..449710020 100644

--- a/memcheck/tests/Makefile.am

+++ b/memcheck/tests/Makefile.am

@@ -392,6 +392,7 @@ check_PROGRAMS = \

 	custom_alloc \

 	custom-overlap \

 	demangle \

+	demangle-rust \

 	big_debuginfo_symbol \

 	deep-backtrace \

 	describe-block \

@@ -505,6 +506,7 @@ endif

 leak_cpp_interior_SOURCES	= leak_cpp_interior.cpp

 demangle_SOURCES = demangle.cpp

+demangle_rust_SOURCES = demangle-rust.c

 # Suppress various gcc warnings which are correct, but for things

 # we are actually testing for at runtime.