Starting in C++17, MSVC introduced a new mangling for function
parameters that are themselves noexcept functions. This patch
makes llvm-undname properly demangle them.
Patch by Zachary Henkel
Differential Revision: https://reviews.llvm.org/D55769
llvm-svn: 350656
Once we detect a 'P', we know we a pointer type is upcoming, so
we make some assumptions about the output that follows. If those
assumptions didn't hold, we would assert. Instead, we should
fail gracefully and propagate the error up.
llvm-svn: 349169
undname prints them, and the information is in the decorated name, so we probably shouldn't lose it when undecorating.
I spot-checked a few of the funnier-looking outputs, and undname has the same output.
Differential Revision: https://reviews.llvm.org/D54396
llvm-svn: 346791
$$Z appears between adjacent expanded parameter packs in the
same template instantiation. We don't need to print it, it's
only there to disambiguate between manglings that would otherwise
be ambiguous. So we just need to parse it and throw it away.
llvm-svn: 341119
These bugs were found by writing a Python script which spidered
the entire Chromium build directory tree demangling every symbol
in every object file. At the start, the tool printed:
Processed 27443 object files.
2926377/2936108 symbols successfully demangled (99.6686%)
9731 symbols could not be demangled (0.3314%)
14589 files crashed while demangling (53.1611%)
After this patch, it prints:
Processed 27443 object files.
41295518/41295617 symbols successfully demangled (99.9998%)
99 symbols could not be demangled (0.0002%)
0 files crashed while demangling (0.0000%)
The issues fixed in this patch are:
* Ignore empty parameter packs. Previously we would encounter
a mangling for an empty parameter pack and add a null node
to the AST. Since we don't print these anyway, we now just
don't add anything to the AST and ignore it entirely. This
fixes some of the crashes.
* Account for "incorrect" string literal demanglings. Apparently
an older version of clang would not truncate mangled string
literals to 32 bytes of encoded character data. The demangling
code however would allocate a 32 byte buffer thinking that it
would not encounter more than this, and overrun the buffer.
We now demangle up to 128 bytes of data, since the buggy
clang would encode up to 32 *characters* of data.
* Extended support for demangling init-fini stubs. If you had
something like
struct Foo {
static vector<string> S;
};
this would generate a dynamic atexit initializer *for the
variable*. We didn't handle this, but now we print something
nice. This is actually an improvement over undname, which will
fail to demangle this at all.
* Fixed one case of static this adjustment. We weren't handling
several thunk codes so we didn't recognize the mangling. These
are now handled.
* Fixed a back-referencing problem. Member pointer templates
should have their components considered for back-referencing
The remaining 99 symbols which can't be demangled are all symbols
which are compiler-generated and undname can't demangle either.
llvm-svn: 341000
Mostly this includes <auto> and <decltype-auto> return values.
Additionally, this fixes a fairly obscure back-referencing bug
that was encountered in one of the C++14 tests, which is that
if you have something like Foo<&bar, &bar> then the `bar`
forms a backreference.
llvm-svn: 340896
This is a pretty large refactor / re-write of the Microsoft
demangler. The previous one was a little hackish because it
evolved as I was learning about all the various edge cases,
exceptions, etc. It didn't have a proper AST and so there was
lots of custom handling of things that should have been much
more clean.
Taking what was learned from that experience, it's now
re-written with a completely redesigned and much more sensible
AST. It's probably still not perfect, but at least it's
comprehensible now to someone else who wants to come along
and make some modifications or read the code.
Incidentally, this fixed a couple of bugs, so I've enabled
the tests which now pass.
llvm-svn: 340710
Previously if you had something like this:
template<typename T>
struct Foo {
template<typename U>
Foo(U);
};
Foo F(3.7);
this would mangle as ??$?0N@?$Foo@H@@QEAA@N@Z
and this would be demangled as:
undname: __cdecl Foo<int>::Foo<int><double>(double)
llvm-undname: __cdecl Foo<int>::Foo<int>(double)
Note the lack of the constructor template parameter in our
demangling.
This patch makes it so we print the constructor argument list.
llvm-svn: 340356
I found these by running llvm-undname over a couple hundred
megabytes of object files generated as part of building chromium.
The issues fixed in this patch are:
1) decltype-auto return types.
2) Indirect vtables (e.g. const A::`vftable'{for `B'})
3) Pointers, references, and rvalue-references to member pointers.
I have exactly one remaining symbol out of a few hundred MB of object
files that produces a name we can't demangle, and it's related to
back-referencing.
llvm-svn: 340341
This is encoded as __E and should print something like
"dynamic initializer for 'Foo'(void)"
This also adds support for dynamic atexit destructor, which is
basically identical but encoded as __F with slightly different
description.
llvm-svn: 340239
A while back I submitted a patch to resolve backreferences
lazily, thinking this that it was not always possible to know
in advance what type you were looking at until you had completed
a full pass over the input, and therefore it would be impossible
to resolve backreferences eagerly.
This was mistaken though, and turned out to be an unrelated
problem. In fact, the reverse is true. You *must* resolve
backreferences eagerly. This is because certain types of nested
mangled symbols do not share a backreference context with their
parent symbol, and as such, if you try to resolve them lazily
their backreference context will have been lost by the time you
finish demangling the entire input. On the other hand, resolving
them eagerly appears to always work, and enables us to port
many more tests over.
llvm-svn: 340126
We were only printing the vtordisp thunk before as the previous
patch was more aimed at getting special operators working, one
of which was a thunk. This patch gets all thunk types to print
properly, and adds a test for each one.
llvm-svn: 340088
Previously, some of the code for actually parsing mangled
operator names was more like formatting code in nature,
and was interspersed with the demangling code which builds
the AST. This means that by the time we got to the printing
code, we had lost all information about what type of operator
we had, and all we were left with was a string that we just
had to print. However, not all operators are actually even
operators. it's basically just a catch-all mangling for
"special names", and for some of the other types it helps
to know when we're actually doing the printing what it is.
This patch changes the way things work by introducing an
OperatorInfo structure and corresponding enumeration. When
we demangle we store the enumeration value and demangled
components separately. This gives more flexibility during
printing.
In doing so, some demanglings of special names which we didn't
previously support come out of this for free, so we now demangle
those.
A few are more complex and are better left for a followup patch
though.
An exhaustive test of every possible operator code is included,
with the ones that don't yet work commented out.
llvm-svn: 340046
When demangling string literals, Microsoft's undname
simply prints 'string'. This patch implements string
literal demangling while doing a bit better than this
by decoding as much of the string as possible and
trying to faithfully reproduce the original string
literal definition.
This is a bit tricky because the different character
types char, char16_t, and char32_t are not uniquely
identified by the mangling, so we have to use a
heuristic to try to guess the character type. But
it works pretty well, and many tests are added to
illustrate the behavior.
Differential Revision: https://reviews.llvm.org/D50806
llvm-svn: 339892
When we have an MD5 mangled name, we shouldn't choke and say
that it's an invalid name. Even though it's impossible to demangle,
we should just output the original name.
llvm-svn: 339891
1) We print __restrict twice on member pointers. This is fixed
and relevant tests are re-enabled.
2) Several tests were disabled because of printing slightly
different output than undname. These were confirmed to be
bugs in undname, so we just re-enable the tests.
3) The test for printing reference temporaries is re-enabled. This
is a clang mangling extension, so we have some flexibility with
how we demangle it. The output currently looks fine, so we just
re-enable the test with no fixes.
llvm-svn: 339708
There are two cases we need to support with extern "C"
functions. The first is the case of a '9' indicating that
the function has no prototype. This occurs when we mangle
a symbol inside of an extern "C" function, but not the
function itself.
The second case is when we have an overloaded extern "C"
functions. In this case we emit $$J0 to indicate this.
This patch adds support for both of these cases.
llvm-svn: 339471
This was broken because of a malformed check line. Incidentally,
this exposed a case where we crash when we should just be returning
an error, so we should fix that. The demangler shouldn't crash due
to user input.
llvm-svn: 339466
Before we wouldn't properly demangle something like
Foo<const int>. Template args have a special escape sequence
'$$C' that is optional, but if it is present contains
qualifiers. So we need to check for this and only if it
present, demangle qualifiers before demangling the type.
With this fix, we re-enable some tests that were previously
marked FIXME.
llvm-svn: 339465
These were uncovered when porting the mangling tests in
ms-templates.cpp from clang/CodeGenCXX over to demangling
tests. The main issues fixed here are surrounding integer
literal signed and unsignedness, empty array dimensions,
and pointer and reference non-type template parameters.
Differential Revision: https://reviews.llvm.org/D50512
llvm-svn: 339434
Template manglings use a fresh back-referencing context, so we
need to do the same. This fixes several existing tests which are
marked as FIXME, so those are now actually run.
llvm-svn: 339275
Function template names are not stored in the backref table,
but non-template function names are. The general pattern seems
to be that when you are demangling a symbol name, if the name
starts with '?' it does not go into the backreference table,
otherwise it does. Note that this even handles the general case
of operator names (template or otherwise) not going into the
back-reference table, anonymous namespaces not going into the
backreference table, etc.
It's important that we apply this check *only* for the
unqualified portion of a name, and only for symbol names.
For example, this does not apply to type names (such as class
templates) and we need to make sure that these still do go
into the backref table.
Differential Revision: https://reviews.llvm.org/D50394
llvm-svn: 339211
After we detected the presence of a template via ?$ we would proceed by
only demangling a simple unqualified name. This means we would fail on
templated operators (and perhaps other yet-to-be-determined things)
This was discovered while doing some refactoring to store richer
semantic information about the demangled types to pave the way for
overhauling the way we handle backreferences. (Specifically, we need to
defer recording or resolving back-references until a symbol has been
completely demangled, because we need to use information that only
occurs later in the mangled string to decide whether a back-reference
should be recorded.)
Differential Revision: https://reviews.llvm.org/D50145
llvm-svn: 338608
This patch fixes demangling of template aliases as template-template
arguments, and also fixes function pointers and references as
not type template parameters. All of these can be properly
demangled now, so I've ported over the test
clang/test/CodeGenCXX/ms-template-callbacks.cpp. All of these
tests pass
llvm-svn: 338340
This patch adds support for demangling r-value references, new
operators such as the ""_foo operator, lambdas, alias types,
nullptr_t, and various other C++11'isms.
There is 1 failing test remaining in this file, which appears to
be related to back-referencing. This type of problem has the
potential to get ugly so I'd rather fix it in a separate patch.
Differential Revision: https://reviews.llvm.org/D50013
llvm-svn: 338324
There are a couple of issues you run into when you start getting into
more complex names, especially with regards to function local statics.
When you've got something like:
int x() {
static int n = 0;
return n;
}
Then this needs to demangle to something like
int `int __cdecl x()'::`1'::n
The nested mangled symbols (e.g. `int __cdecl x()` in the above
example) also share state with regards to back-referencing, so
we need to be able to re-use the demangler in the middle of
demangling a symbol while sharing back-ref state.
To make matters more complicated, there are a lot of ambiguities
when demangling a symbol's qualified name, because a function local
scope pattern (usually something like `?1??name?`) looks suspiciously
like many other possible things that can occur, such as `?1` meaning
the second back-ref and disambiguating these cases is rather
interesting. The `?1?` in a local scope pattern is actually a special
case of the more general pattern of `? + <encoded number> + ?`, where
"encoded number" can itself have embedded `@` symbols, which is a
common delimeter in mangled names. So we have to take care during the
disambiguation, which is the reason for the overly complicated
`isLocalScopePattern` function in this patch.
I've added some pretty obnoxious tests to exercise all of this, which
exposed several other problems related to back-referencing, so those
are fixed here as well. Finally, I've uncommented some tests that were
previously marked as `FIXME`, since now these work.
Differential Revision: https://reviews.llvm.org/D49965
llvm-svn: 338226
Properly demangle function parameter back-references.
Previously we treated lists of function parameters and template
parameters the same. There are some important differences with regards
to back-references, and some less important differences regarding which
characters can appear before or after the name.
The important differences are that with a given type T, all instances of
a function parameter list share the same global back-ref table.
Specifically, if X and Y are function pointers, then there are 3
entities in the declaration X func(Y) which all affect and are affected
by the master parameter back-ref table:
1) The parameter list of X's function type
2) the parameter list of func itself
3) The parameter list of Y's function type.
The previous code would create a back-reference table that was local to
a single parameter list, so it would not be shared across parameter
lists.
This was discovered when porting ms-back-references.test from clang's
mangling tests. All of these tests should now pass with the new changes.
In doing so, I split the function for parsing template and function
parameters into two separate functions. This makes the template
parameter list parsing code in particular very small and easy to
understand now.
Differential Revision: https://reviews.llvm.org/D49875
llvm-svn: 338075
For function pointers, we would print something like
int __cdecl (*)(int)
We need to move the calling convention inside, and print
int (__cdecl *)(int)
This patch implements this change for regular function pointers as
well as member function pointers.
llvm-svn: 338068
This converts the arg qualifier mangling tests from
clang/CodeGenCXX/mangle-ms-arg-qualifiers.cpp to demangling tests.
Most tests already pass, so this patch doesn't come with any
functional change, just the addition of new tests. The few tests
that don't pass are left in with a FIXME label so that they don't
run but serve as documentation about what still doesn't work.
llvm-svn: 338067
None of these tests pass yet so they are commented out, but I'm
adding them with a FIXME label so that they don't get lost when
copying tests over from clang's mangling tests. Currently these
tests are all commented out.
llvm-svn: 338066
After this patch, we can now properly demangle pointers to member
functions. The calling convention is located in the wrong place,
but this will be fixed in a followup since it also affects non
member function pointers.
Differential Revision: https://reviews.llvm.org/D49639
llvm-svn: 338065
This adds initial support for a demangling library (LLVMDemangle)
and tool (llvm-undname) for demangling Microsoft names. This
doesn't cover 100% of cases and there are some known limitations
which I intend to address in followup patches, at least until such
time that we have (near) 100% test coverage matching up with all
of the test cases in clang/test/CodeGenCXX/mangle-ms-*.
Differential Revision: https://reviews.llvm.org/D49552
llvm-svn: 337584
`c++filt` when given no arguments runs as a REPL, decoding each line as a
decorated name. Unify the test structure to be more uniform, with the tests for
llvm-cxxfilt living under test/tools/llvm-cxxfilt.
llvm-svn: 286777
This adds a copy of the demangler in libcxxabi.
The code also has no dependencies on anything else in LLVM. To enforce
that I added it as another library. That way a BUILD_SHARED_LIBS will
fail if anyone adds an use of StringRef for example.
The no llvm dependency combined with the fact that this has to build
on linux, OS X and Windows required a few changes to the code. In
particular:
No constexpr.
No alignas
On OS X at least this library has only one global symbol:
__ZN4llvm16itanium_demangleEPKcPcPmPi
My current plan is:
Commit something like this
Change lld to use it
Change lldb to use it as the fallback
Add a few #ifdefs so that exactly the same file can be used in
libcxxabi to export abi::__cxa_demangle.
Once the fast demangler in lldb can handle any names this
implementation can be replaced with it and we will have the one true
demangler.
llvm-svn: 280732
