Ping. Is this OK to commit now? I am not sure who can approve this.
On Sun, Jan 16, 2022 at 01:35:34AM +0100, Mark Wielaard wrote: > Rust symbols can have a .suffix because of compiler transformations. > These can be ignored in the demangled name. Which is what this patch > implements. By stopping at the first dot for v0 symbols and searching > backwards to the ending 'E' for legacy symbols. > > An alternative implementation could be to follow what C++ does and > represent these as [clone .suffix] tagged onto the demangled name. > But this seems somewhat confusing since it results in a demangled > name that cannot be mangled again. And it would mean trying to > decode compiler internal naming. > > https://bugs.kde.org/show_bug.cgi?id=445916 > https://github.com/rust-lang/rust/issues/60705 > > libiberty/Changelog > > * rust-demangle.c (rust_demangle_callback): Ignore everything > after '.' char in sym for v0. For legacy symbols search > backwards to find the last 'E' before any '.'. > * testsuite/rust-demangle-expected: Add new .suffix testcases. > --- > libiberty/rust-demangle.c | 21 ++++++++++++++--- > libiberty/testsuite/rust-demangle-expected | 26 ++++++++++++++++++++++ > 2 files changed, 44 insertions(+), 3 deletions(-) > > V3 - Add more testcases > - Allow @ in legacy symbols (which can appear in the .suffix) > > diff --git a/libiberty/rust-demangle.c b/libiberty/rust-demangle.c > index 18c760491bdc..42c88161da30 100644 > --- a/libiberty/rust-demangle.c > +++ b/libiberty/rust-demangle.c > @@ -1340,13 +1340,19 @@ rust_demangle_callback (const char *mangled, int > options, > /* Rust symbols (v0) use only [_0-9a-zA-Z] characters. */ > for (p = rdm.sym; *p; p++) > { > + /* Rust v0 symbols can have '.' suffixes, ignore those. */ > + if (rdm.version == 0 && *p == '.') > + break; > + > rdm.sym_len++; > > if (*p == '_' || ISALNUM (*p)) > continue; > > - /* Legacy Rust symbols can also contain [.:$] characters. */ > - if (rdm.version == -1 && (*p == '$' || *p == '.' || *p == ':')) > + /* Legacy Rust symbols can also contain [.:$] characters. > + Or @ in the .suffix (which will be skipped, see below). */ > + if (rdm.version == -1 && (*p == '$' || *p == '.' || *p == ':' > + || *p == '@')) > continue; > > return 0; > @@ -1355,7 +1361,16 @@ rust_demangle_callback (const char *mangled, int > options, > /* Legacy Rust symbols need to be handled separately. */ > if (rdm.version == -1) > { > - /* Legacy Rust symbols always end with E. */ > + /* Legacy Rust symbols always end with E. But can be followed by a > + .suffix (which we want to ignore). */ > + int dot_suffix = 1; > + while (rdm.sym_len > 0 && > + !(dot_suffix && rdm.sym[rdm.sym_len - 1] == 'E')) > + { > + dot_suffix = rdm.sym[rdm.sym_len - 1] == '.'; > + rdm.sym_len--; > + } > + > if (!(rdm.sym_len > 0 && rdm.sym[rdm.sym_len - 1] == 'E')) > return 0; > rdm.sym_len--; > diff --git a/libiberty/testsuite/rust-demangle-expected > b/libiberty/testsuite/rust-demangle-expected > index 7dca315d0054..b565084cfefa 100644 > --- a/libiberty/testsuite/rust-demangle-expected > +++ b/libiberty/testsuite/rust-demangle-expected > @@ -295,3 +295,29 @@ _RMCs4fqI2P2rA04_13const_genericINtB0_4CharKc2202_E > --format=auto > _RNvNvMCs4fqI2P2rA04_13const_genericINtB4_3FooKpE3foo3FOO > <const_generic::Foo<_>>::foo::FOO > +# > +# Suffixes > +# > +--format=rust > +_RNvMs0_NtCs5l0EXMQXRMU_21rustc_data_structures17obligation_forestINtB5_16ObligationForestNtNtNtCsdozMG8X9FIu_21rustc_trait_selection6traits7fulfill26PendingPredicateObligationE22register_obligation_atB1v_.llvm.8517020237817239694 > +<rustc_data_structures::obligation_forest::ObligationForest<rustc_trait_selection::traits::fulfill::PendingPredicateObligation>>::register_obligation_at > +--format=rust > +_ZN4core3ptr85drop_in_place$LT$std..rt..lang_start$LT$$LP$$RP$$GT$..$u7b$$u7b$closure$u7d$$u7d$$GT$17h27f14859c664490dE.llvm.8091179795805947855 > +core::ptr::drop_in_place<std::rt::lang_start<()>::{{closure}}> > +# old style rustc llvm thinlto > +--format=rust > +_ZN9backtrace3foo17hbb467fcdaea5d79bE.llvm.A5310EB9 > +backtrace::foo > +--format=rust > +_ZN9backtrace3foo17hbb467fcdaea5d79bE.llvm.A5310EB9@@16 > +backtrace::foo > +# new style rustc llvm thinlto > +--format=rust > +_RC3foo.llvm.9D1C9369 > +foo > +--format=rust > +_RC3foo.llvm.9D1C9369@@16 > +foo > +--format=rust > +_RNvC9backtrace3foo.llvm.A5310EB9 > +backtrace::foo > -- > 2.30.2 >
