libiberty: Add Rust symbol demangling.

Adds Rust symbol demangler. Rust mangles symbols using GNU_V3 style,
adding a hash and various special character subtitutions. This adds
a new rust style to cplus_demangle and adds 3 helper functions
rust_demangle, rust_demangle_sym and rust_is_mangled.

rust-demangle.c was written by David. Mark did the code formatting to
GNU style and integration into the gcc/libiberty build system and
testsuite.

include/ChangeLog:

2016-11-03  David Tolnay <dtolnay@gmail.com>
           Mark Wielaard  <mark@klomp.org>

       * demangle.h (DMGL_RUST): New macro.
       (DMGL_STYLE_MASK): Add DMGL_RUST.
       (demangling_styles): Add dlang_rust.
       (RUST_DEMANGLING_STYLE_STRING): New macro.
       (RUST_DEMANGLING): New macro.
       (rust_demangle): New prototype.
       (rust_is_mangled): Likewise.
       (rust_demangle_sym): Likewise.

libiberty/ChangeLog:

2016-11-03  David Tolnay <dtolnay@gmail.com>
           Mark Wielaard  <mark@klomp.org>

       * Makefile.in (CFILES): Add rust-demangle.c.
       (REQUIRED_OFILES): Add rust-demangle.o.
       * cplus-dem.c (libiberty_demanglers): Add rust_demangling case.
       (cplus_demangle): Handle RUST_DEMANGLING.
       (rust_demangle): New function.
       * rust-demangle.c: New file.
       * testsuite/Makefile.in (really-check): Add check-rust-demangle.
       (check-rust-demangle): New rule.
       * testsuite/rust-demangle-expected: New file.

2 files changed, 166 insertions, 2 deletions

diff --git a/libiberty/testsuite/Makefile.in b/libiberty/testsuite/Makefile.in
index 8f5f7b5..da0b2f4 100644
--- a/libiberty/testsuite/Makefile.in
+++ b/libiberty/testsuite/Makefile.in
@@ -45,8 +45,8 @@ all:
 # CHECK is set to "really_check" or the empty string by configure.
 check: @CHECK@
 
-really-check: check-cplus-dem check-d-demangle check-pexecute check-expandargv \
-		check-strtol
+really-check: check-cplus-dem check-d-demangle check-rust-demangle \
+		check-pexecute check-expandargv check-strtol
 
 # Run some tests of the demangler.
 check-cplus-dem: test-demangle $(srcdir)/demangle-expected
@@ -55,6 +55,9 @@ check-cplus-dem: test-demangle $(srcdir)/demangle-expected
 check-d-demangle: test-demangle $(srcdir)/d-demangle-expected
 	./test-demangle < $(srcdir)/d-demangle-expected
 
+check-rust-demangle: test-demangle $(srcdir)/rust-demangle-expected
+	./test-demangle < $(srcdir)/rust-demangle-expected
+
 # Check the pexecute code.
 check-pexecute: test-pexecute
 	./test-pexecute
diff --git a/libiberty/testsuite/rust-demangle-expected b/libiberty/testsuite/rust-demangle-expected
new file mode 100644
index 0000000..0b4288f
--- /dev/null
+++ b/libiberty/testsuite/rust-demangle-expected
@@ -0,0 +1,161 @@
+# This file holds test cases for the Rust demangler.
+# Each test case looks like this:
+#  options
+#  input to be demangled
+#  expected output
+#
+# See demangle-expected for documentation of supported options.
+#
+# A line starting with `#' is ignored.
+# However, blank lines in this file are NOT ignored.
+#
+############
+#
+# Coverage Tests
+#
+#
+# Demangles as rust symbol.
+--format=rust
+_ZN4main4main17he714a2e23ed7db23E
+main::main
+# Also demangles as c++ gnu v3 mangled symbol. But with extra Rust hash.
+--format=gnu-v3
+_ZN4main4main17he714a2e23ed7db23E
+main::main::he714a2e23ed7db23
+# But auto should demangle fully gnu-v3 -> rust -> demangled, not partially.
+--format=auto
+_ZN4main4main17he714a2e23ed7db23E
+main::main
+# Hash is exactly 16 hex chars. Not more.
+--format=auto
+_ZN4main4main18h1e714a2e23ed7db23E
+main::main::h1e714a2e23ed7db23
+# Not less.
+--format=auto
+_ZN4main4main16h714a2e23ed7db23E
+main::main::h714a2e23ed7db23
+# And not non-hex.
+--format=auto
+_ZN4main4main17he714a2e23ed7db2gE
+main::main::he714a2e23ed7db2g
+# $XX$ substitutions should not contain just numbers.
+--format=auto
+_ZN4main4$99$17he714a2e23ed7db23E
+main::$99$::he714a2e23ed7db23
+# _ at start of path should be removed.
+# ".." translates to "::" "$GT$" to ">" and "$LT$" to "<".
+--format=rust
+_ZN71_$LT$Test$u20$$u2b$$u20$$u27$static$u20$as$u20$foo..Bar$LT$Test$GT$$GT$3bar17h930b740aa94f1d3aE
+<Test + 'static as foo::Bar<Test>>::bar
+#
+--format=rust
+_ZN54_$LT$I$u20$as$u20$core..iter..traits..IntoIterator$GT$9into_iter17h8581507801fb8615E
+<I as core::iter::traits::IntoIterator>::into_iter
+#
+--format=rust
+_ZN10parse_tsan4main17hdbbfdf1c6a7e27d9E
+parse_tsan::main
+#
+--format=rust
+_ZN65_$LT$std..env..Args$u20$as$u20$core..iter..iterator..Iterator$GT$4next17h420a7c8d0c7eef40E
+<std::env::Args as core::iter::iterator::Iterator>::next
+#
+--format=rust
+_ZN4core3str9from_utf817hdcea28871313776dE
+core::str::from_utf8
+#
+--format=rust
+_ZN4core3mem7size_of17h18bde9bb8c22e2cfE
+core::mem::size_of
+#
+--format=rust
+_ZN5alloc4heap8allocate17hd55c03e6cb81d924E
+alloc::heap::allocate
+#
+--format=rust
+_ZN4core3ptr8null_mut17h736cce09ca0ac11aE
+core::ptr::null_mut
+#
+--format=rust
+_ZN4core3ptr31_$LT$impl$u20$$BP$mut$u20$T$GT$7is_null17h7f9de798bc3f0879E
+core::ptr::<impl *mut T>::is_null
+#
+--format=rust
+_ZN40_$LT$alloc..raw_vec..RawVec$LT$T$GT$$GT$6double17h4166e2b47539e1ffE
+<alloc::raw_vec::RawVec<T>>::double
+#
+--format=rust
+_ZN39_$LT$collections..vec..Vec$LT$T$GT$$GT$4push17hd4b6b23c1b88141aE
+<collections::vec::Vec<T>>::push
+#
+--format=rust
+_ZN70_$LT$collections..vec..Vec$LT$T$GT$$u20$as$u20$core..ops..DerefMut$GT$9deref_mut17hf299b860dc5a831cE
+<collections::vec::Vec<T> as core::ops::DerefMut>::deref_mut
+#
+--format=rust
+_ZN63_$LT$core..ptr..Unique$LT$T$GT$$u20$as$u20$core..ops..Deref$GT$5deref17hc784b4a166cb5e5cE
+<core::ptr::Unique<T> as core::ops::Deref>::deref
+#
+--format=rust
+_ZN40_$LT$alloc..raw_vec..RawVec$LT$T$GT$$GT$3ptr17h7570b6e9070b693bE
+<alloc::raw_vec::RawVec<T>>::ptr
+#
+--format=rust
+_ZN4core3ptr31_$LT$impl$u20$$BP$mut$u20$T$GT$7is_null17h0f3228f343444ac8E
+core::ptr::<impl *mut T>::is_null
+#
+--format=rust
+_ZN53_$LT$$u5b$T$u5d$$u20$as$u20$core..slice..SliceExt$GT$10as_mut_ptr17h153241df1c7d1666E
+<[T] as core::slice::SliceExt>::as_mut_ptr
+#
+--format=rust
+_ZN11collections5slice29_$LT$impl$u20$$u5b$T$u5d$$GT$10as_mut_ptr17hf12a6d0409938c96E
+collections::slice::<impl [T]>::as_mut_ptr
+#
+--format=rust
+_ZN4core3ptr5write17h651fe53ec860e780E
+core::ptr::write
+#
+--format=rust
+_ZN65_$LT$std..env..Args$u20$as$u20$core..iter..iterator..Iterator$GT$4next17h420a7c8d0c7eef40E
+<std::env::Args as core::iter::iterator::Iterator>::next
+#
+--format=rust
+_ZN54_$LT$I$u20$as$u20$core..iter..traits..IntoIterator$GT$9into_iter17he06cb713aae5b465E
+<I as core::iter::traits::IntoIterator>::into_iter
+#
+--format=rust
+_ZN71_$LT$collections..vec..IntoIter$LT$T$GT$$u20$as$u20$core..ops..Drop$GT$4drop17hf7f23304ebe62eedE
+<collections::vec::IntoIter<T> as core::ops::Drop>::drop
+#
+--format=rust
+_ZN86_$LT$collections..vec..IntoIter$LT$T$GT$$u20$as$u20$core..iter..iterator..Iterator$GT$4next17h04b3fbf148c39713E
+<collections::vec::IntoIter<T> as core::iter::iterator::Iterator>::next
+#
+--format=rust
+_ZN75_$LT$$RF$$u27$a$u20$mut$u20$I$u20$as$u20$core..iter..iterator..Iterator$GT$4next17ha050492063e0fd20E
+<&'a mut I as core::iter::iterator::Iterator>::next
+# Different hashes are OK, they are just stripped.
+--format=rust
+_ZN13drop_contents17hfe3c0a68c8ad1c74E
+drop_contents
+#
+--format=rust
+_ZN13drop_contents17h48cb59bef15bb555E
+drop_contents
+#
+--format=rust
+_ZN4core3mem7size_of17h900b33157bf58f26E
+core::mem::size_of
+#
+--format=rust
+_ZN67_$LT$alloc..raw_vec..RawVec$LT$T$GT$$u20$as$u20$core..ops..Drop$GT$4drop17h96a5cf6e94807905E
+<alloc::raw_vec::RawVec<T> as core::ops::Drop>::drop
+#
+--format=rust
+_ZN68_$LT$core..nonzero..NonZero$LT$T$GT$$u20$as$u20$core..ops..Deref$GT$5deref17hc49056f882aa46dbE
+<core::nonzero::NonZero<T> as core::ops::Deref>::deref
+#
+--format=rust
+_ZN63_$LT$core..ptr..Unique$LT$T$GT$$u20$as$u20$core..ops..Deref$GT$5deref17h19f2ad4920655e85E
+<core::ptr::Unique<T> as core::ops::Deref>::deref