Demangler::parse() for MD5 names would:
1. Put all remaining text into the MD5 name sight unseen
2. Not modify MangledName
This meant that if the demangler recursively called parse() (e.g. in
demangleLocallyScopedNamePiece()), every recursive call that started on
an MD5 name would add all remaining bytes to the output buffer but
only advance the input by a byte. For valid inputs, MD5 types are
never (well, see comments for 2 exceptions) nested, but for invalid
input this could cause memory use quadratic in the input size.
llvm-svn: 361744
If a template parameter refers to a pointer to member, but the mangling
of that was a string literal instead of a real symbol, llvm-undname used
to crash instead of rejecting the input.
llvm-svn: 361402
llvm-undname used to put '\x' in front of every pair of nibbles, but
u"\xD7\xFF" produces a string with 6 bytes: \xD7 \0 \xFF \0 (and \0\0). Correct
for a single character (plus terminating \0) is u\xD7FF instead.
Now, wchar_t, char16_t, and char32_t strings roundtrip from source to
clang-cl (and cl.exe) and then llvm-undname.
(...at least as long as it's not a string like L"\xD7FF" L"foo" which
gets demangled as L"\xD7FFfoo", where the compiler then considers the
"f" as part of the hex escape. That seems ok.)
Also add a comment saying that the "almost-valid" char32_t string I
added in my last commit is actually produced by compilers.
llvm-svn: 358857
If a unsigned with all 4 bytes non-0 was passed to outputHex(), there
were two off-by-ones in it:
- Both MaxPos and Pos left space for the final \0, which left the buffer
one byte to small. Set MaxPos to 16 instead of 15 to fix.
- The `assert(Pos >= 0);` was after a `Pos--`, move it up one line.
Since valid Unicode codepoints are <= 0x10ffff, this could never really
happen in practice.
Found by oss-fuzz.
llvm-svn: 358856
- Don't assert when a string looks like a u32 string to the heuristic
but doesn't have a length that's 0 mod 4. Instead, classify those
as u16 with embedded \0 chars. Found by oss-fuzz.
- Print embedded nul bytes as \0 instead of \x00.
llvm-svn: 358835
Similar to r358421: A StructorIndentifierNode has a Class field which
is read when printing it, but if the StructorIndentifierNode appears in
a template argument then demangleFullyQualifiedSymbolName() which sets
Class isn't called. Since StructorIndentifierNodes are always leaf
names, we can just reject them as well.
Found by oss-fuzz.
llvm-svn: 358491
- Make `allocUnalignedBuffer` look more like `allocArray` and `alloc`.
No behavior change.
- Change `Head->Used < Head->Capacity` to `Head->Used <= Head->Capacity`
in `allocArray` and `alloc`. No intended behavior change, might be a
minuscule memory usage improvement. Noticed this since it was the logic
used in `allocUnalignedBuffer`.
- Don't let `allocArray` alloc too small buffers for names that have
more than 512 levels of nesting (in 64-bit builds). Fixes a heap
buffer overflow found by oss-fuzz.
Differential Revision: https://reviews.llvm.org/D60774
llvm-svn: 358489
A ConversionOperatorIdentifierNode has a TargetType which is read when
printing it, but if the ConversionOperatorIdentifierNode appears in a
template argument there's nothing that can provide the TargetType.
Normally the COIN is a symbol (leaf) name and takes its TargetType from the
symbol's type, but in a template argument context the COIN can only be
either a non-leaf name piece or a type, and must hence be invalid.
Similar to the COIN check in demangleDeclarator().
Found by oss-fuzz.
llvm-svn: 358421
This fixes a regression from https://reviews.llvm.org/D60354. We used to
SymbolNode *Symbol = demangleEncodedSymbol(MangledName, QN);
if (Symbol) {
Symbol->Name = QN;
}
but changed that to
SymbolNode *Symbol = demangleEncodedSymbol(MangledName, QN);
if (Error)
return nullptr;
Symbol->Name = QN;
and one branch somewhere returned a nullptr without setting Error.
Looking at the code changed in r340083 and r340710 that branch looks
like a remnant from an earlier attempt to demangle RTTI descriptors
that has since been rewritten -- so just remove this branch. It
shouldn't change behavior for correctly mangled symbols.
llvm-svn: 358112
For functions whose callers don't check that enough input is present,
add checks at the start of the function that enough input is there and
set Error otherwise.
For functions that return AST objects, return nullptr instead of
incomplete AST objects with nullptr fields if an error occurred during
the function.
Introduce a new function demangleDeclarator() for the sequence
demangleFullyQualifiedSymbolName(); demangleEncodedSymbol() and
use it in the two places that had this sequence. Let this new function
check that ConversionOperatorIdentifiers have a valid TargetType.
Some of the bad inputs found by oss-fuzz, others by inspection.
Differential Revision: https://reviews.llvm.org/D60354
llvm-svn: 357936
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
Nico Weber