We previously had support for char and wchar_t string literals. VS 2015
added support for char16_t and char32_t.
String literals must be mangled in the MS ABI in order for them to be
deduplicated across translation units: their linker has no notion of
mergeable section. Instead, they use the mangled name to make a COMDAT
for the string literal; the COMDAT will merge with other COMDATs in
other object files.
This allows strings in object files generated by clang to get merged
with strings in object files generated by MSVC.
llvm-svn: 222564
Wire it through everywhere we have support for fastcall, essentially.
This allows us to parse the MSVC "14" CTP headers, but we will
miscompile them because LLVM doesn't support __vectorcall yet.
Reviewed By: Aaron Ballman
Differential Revision: http://reviews.llvm.org/D5808
llvm-svn: 220573
Plumb through the full QualType of the TemplateArgument::Declaration, as
it's insufficient to only know whether the type is a reference or
pointer (that was necessary for mangling, but insufficient for debug
info). This shouldn't increase the size of TemplateArgument as
TemplateArgument::Integer is still longer by another 32 bits.
Several bits of code were testing that the reference-ness of the
parameters matched, but this seemed to be insufficient (various other
features of the type could've mismatched and wouldn't've been caught)
and unnecessary, at least insofar as removing those tests didn't cause
anything to fail.
(Richard - perchaps you can hypothesize why any of these checks might
need to test reference-ness of the parameters (& explain why
reference-ness is part of the mangling - I would've figured that for the
reference-ness to be different, a prior template argument would have to
be different). I'd be happy to add them in/beef them up and add test
cases if there's a reason for them)
llvm-svn: 219900
This changes the scope discriminator's behavior to start at '1' instead
of '0'. Symbol table diffing, for ABI compatibility testing, kept
finding these as false positives.
llvm-svn: 219075
This patch replaces the back reference StringMap from the MS mangler
with a SmallVector of strings. My previous patches reduced the number of
hashes involved in back reference lookups, this one removes them
completely. The back reference map contains at most 10 entries, which
are likely to be of varying sizes and different initial subsequences,
and which can easily became huge (due to templates and namespaces).
The solution presented is the simplest possible one. Nevertheless, it's
enough to reduce compilation times for a particular test case from 11.1s
to 9s, versus 8.58s for the Itanium ABI. Possible further improvements
include using a sorted vector (carefully to not introduce an extra
comparison), storing the string contents in a common arena, and/or keep
the string storage in the context for reuse.
Patch by Agustín Bergé.
llvm-svn: 218461
There are situations when clang knows that the C1 and C2 constructors
or the D1 and D2 destructors are identical. We already optimize some
of these cases, but cannot optimize it when the GlobalValue is
weak_odr.
The problem with weak_odr is that an old TU seeing the same code will
have a C1 and a C2 comdat with the corresponding symbols. We cannot
suddenly start putting the C2 symbol in the C1 comdat as we cannot
guarantee that the linker will not pick a .o with only C1 in it.
The solution implemented by GCC is to expand the ABI to have a comdat
whose name uses a C5/D5 suffix and always has both symbols. That is
what this patch implements.
llvm-svn: 217874
MSVC "14" CTP 3 has fixed it's mangling for alias templates when used as
template-template arguments; update clang to be compatible with this
mangling.
llvm-svn: 215972
C++11 allows this qualifiers to exist on function types when used in
template arguments. Previously, I believed it wasn't possible because
MSVC rejected declarations like: S<int () const &> s;
However, it turns out MSVC properly allows them in using declarations;
updated clang to be compatible with this mangling.
llvm-svn: 215464
It is possible for lambdas to get the same mangling number because they
may exist in different mangling contexts. To handle this correctly,
mangle the context into the name as well.
llvm-svn: 214947
The MS mangling scheme apparently has separate manglings for type and
non-type parameter packs when they are empty. Match template arguments
with parameters during mangling; check the parameter to see if it was
destined to hold type-ish things or nontype-ish things.
Differential Revision: http://reviews.llvm.org/D4792
llvm-svn: 214932
A templated using declaration may be used as a template-template
argument.
Unfortunately, the VS "14" chooses '?' as the sole marker for the
argument. This is problematic because it presupposes the possibility of
using more than one template-aliases as arguments to the same template.
This fixes PR20047.
llvm-svn: 214290
Avoid a second key lookup when the back reference key is going to be
inserted in the StringMap. The string lookups in the msmangler are the
main responsible for the huge overhead when compared to the itanium
mangler. This patch makes a small but noticeable improvement.
Reviewed by: rnk
Differential Revision: http://reviews.llvm.org/D4130
Patch by Agustín Bergé!
llvm-svn: 211813
VarDecl provides a method getSourceRange(), which provides a more
robust way of getting the SourceRange since the TypeSourceInfo can
be null in certain cases.
Reviewed by: majnemer
Differential Revision: http://reviews.llvm.org/D4281
llvm-svn: 211667
r210637 regressed CodeGenCXX/mangle-ms-templates-memptrs.cpp because it
did not believe that there is a distinction between class templates and
function templates.
Sadly, there is. Function templates should behave in a compatible
manner with MSVC.
llvm-svn: 210642
Summary:
Previously, we would mangle nullptr pointer-to-member-functions in class
templates with a mangling we invented because contemporary versions of
MSVC would crash when trying to compile such code.
However, VS "14" can successfully compile these sorts of template
instantiations. This commit updates our mangling to be compatible with
theirs.
Reviewers: rnk
Reviewed By: rnk
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4059
llvm-svn: 210637
Use mangled template instantiation name as key for back references.
Templates have their own context for back references, so their mangling
is always the same regardless of context. This avoids mangling template
instantiations twice.
Patch by Agustín Bergé!
llvm-svn: 210416
Straightforward implementation of UDLs, it's compatible with VS "14".
This nearly completes our implementation of C++ name mangling for the
MS-ABI.
llvm-svn: 210197
Enables the emission of MS-compatible RTTI data structures for use with
typeid, dynamic_cast and exceptions. Does not implement dynamic_cast
or exceptions. As an artiface, typeid works in some cases but proper
support an testing will coming in a subsequent patch.
majnemer has fuzzed the results. Test cases included.
Differential Revision: http://reviews.llvm.org/D3833
llvm-svn: 209523
Implement what we currently believe is the mangling scheme for RTTI
data. Tests will be added in a later commit which actually generate
RTTI data.
llvm-svn: 208661
Summary:
Previously, we would generate a single name for all reference
temporaries and allow LLVM to rename them for us. Instead, number the
reference temporaries as we build them in Sema.
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D3554
llvm-svn: 207776
This can actually be non-zero if you override a function from a virtual
base and you have forced the most_general pointer to member
representation.
llvm-svn: 205727
The MS ABI forces us into catch-22 when it comes to functions which
return types which are local:
- A function is mangled with it's return type.
- A type is mangled with it's surrounding context.
Avoid this by mangling auto and decltype(autp) directly into the
function's return type. Using this mangling has the double advantage of
being compatible with the C++ standard without crashing the compiler.
N.B. For the curious, the MSVC mangling leads to collisions amongst
template functions and either crashes when faced with local types or is
otherwise incapable of returning them.
llvm-svn: 205282
It turns out that the ranges where the '?' <letter> manglings occur are
identical to the ranges of ASCII characters OR'd with 0x80.
Thanks to Richard Smith for the insight!
No functional change.
llvm-svn: 205270
The delta between '\xe1' and '\xc1' is equivalent to the one between 'a'
and 'A'. This allows us to reuse the computation between '\xe1' and
'\xfa' for the '\xc1' to '\xda' case.
No functionality change.
llvm-svn: 205128
COFF doesn't have mergeable sections so LLVM/clang's normal tactics for
string deduplication will not have any effect.
To remedy this we place each string inside it's own section and mark
the section as IMAGE_COMDAT_SELECT_ANY. However, we can only do this if the
string has an external name that we can generate from it's contents.
To be compatible with MSVC, we must use their scheme. Otherwise identical
strings in translation units from clang may not be deduplicated with
translation units in MSVC.
This fixes PR18248.
N.B. We will not attempt to do anything with a string literal which is not of
type 'char' or 'wchar_t' because their compiler does not support unicode
string literals as of this date. Further, we avoid doing this if
either -fwritable-strings or -fsanitize=address are present.
This reverts commit r204596.
llvm-svn: 204675
This commit cleans up a few accidents:
- Do not rely on the order in which StringLiteral lays out bytes.
- Use a more efficient mechanism for handling so-called
"special-mappings" when mangling string literals.
- There is no need to allocate a copy of the mangled name.
- Add the test written for r204562.
Thanks to Richard Smith for pointing these out!
llvm-svn: 204586
Will Wilson