Every non-testcase use of OutputBuffer contains code to allocate an
initial buffer (using either 128 or 1024 as initial guesses). There's
now no need to do that, given recent changes to the buffer extension
heuristics -- it allocates a 1k(ish) buffer on first need.
Just pass in a buffer (if any) to the constructor. Thus the
OutputBuffer's ownership of the buffer starts at its own lifetime
start. We can reduce the lifetime of this object in several cases.
That new constructor takes a 'size_t *' for the size argument, as all
uses with a non-null buffer are passing through a malloc'd buffer from
their own caller in this manner.
The buffer reset member function is never used, and is deleted.
The original buffer initialization code would return a failure code if
that first malloc failed. Existing code either ignored that, called
std::terminate with a FIXME, or returned an error code.
But that's not foolproof anyway, as a subsequent buffer extension
failure ends up calling std::terminate. I am working on addressing
that unfortunate failure mode in a manner more consistent with the C++
ABI design.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D122604
The rust demangler has some odd buffer handling code, which will copy
the demangled string into the provided buffer, if it will fit.
Otherwise it uses the allocated buffer it made. But the length of the
incoming buffer will have come from a previous call, which was the
length of the demangled string -- not the buffer size. And of course,
we're unconditionally allocating a temporary buffer in the first
place. So we don't actually get buffer reuse, and we get a memcpy in
somecases.
However, nothing in LLVM ever passes in a non-null pointer. Neither
does anything pass in a status pointer that is then made use of. The
only exercise these have is in the test suite.
So let's just make the rust demangler have the same API as the dlang
demangler.
Reviewed By: tmiasko
Differential Revision: https://reviews.llvm.org/D123420
The demangler has a utility class 'SwapAndRestore'. That name is
confusing. It's not swapping anything, and the restore part happens at
the object's destruction. What it's actually doing is allowing a
override of some value that is dynamically accessible within the
lifetime of a lexical scope. Thus rename it to ScopedOverride, and
tweak it's member variable names.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D122606
This patch is a refactor to implement prepend afterwards. Since this changes a lot of files and to conform with guidelines, I will separate this from the implementation of prepend. Related to the discussion in https://reviews.llvm.org/D111414 , so please read it for more context.
Reviewed By: #libc_abi, dblaikie, ldionne
Differential Revision: https://reviews.llvm.org/D111947
Rust allows use of non-ASCII identifiers, which in Rust mangling scheme
are encoded using Punycode.
The encoding deviates from the standard by using an underscore as the
separator between ASCII part and a base-36 encoding of non-ASCII
characters (avoiding hypen-minus in the symbol name). Other than that,
the encoding follows the standard, and the decoder implemented here in
turn follows the one given in RFC 3492.
To avoid an extra intermediate memory allocation while decoding
Punycode, the interface of OutputStream is extended with an insert
method.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D104366
Move content of the "public" header into the implementation file.
This also renames two enumerations that were previously used through
`rust_demangle::` scope, to avoid breaking a build bot with older
version of GCC that rejects uses of enumerator through `E::A` if there
is a variable with the same name as enumeration `E` in the scope.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D104362
Allow mangled names to include an arbitrary dot suffix, akin to vendor
specific suffix in Itanium mangling.
Primary motivation is a support for symbols renamed during ThinLTO
import / promotion (ThinLTO is the default configuration for optimized
builds in rustc).
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D104358
Add a demangling support for a small subset of a new Rust mangling
scheme, with complete support planned as a follow up work.
Intergate Rust demangling into llvm-cxxfilt and use llvm-cxxfilt for
end-to-end testing. The new Rust mangling scheme uses "_R" as a prefix,
which makes it easy to disambiguate it from other mangling schemes.
The public API is modeled after __cxa_demangle / llvm::itaniumDemangle,
since potential candidates for further integration use those.
Reviewed By: dblaikie
Differential Revision: https://reviews.llvm.org/D101444
Kirill Stoimenov