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
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.
llvm-svn: 204562
If a guard variable will be created for an entity at global scope,
then we cannot rely on the scope depth to disambiguate names for us.
Instead, mangle the entire variable into the guard to ensure it's uniqueness.
llvm-svn: 203151
Initializers and finalizers for static data members have the variable's
access-specifier, storage-class, type and CV-qualifiers mangled in.
llvm-svn: 203145
Use a scheme inspired by the Itanium ABI to properly implement the
mangling of lambdas.
N.B. The incredibly astute observer will notice that we do not generate
external names that are identical, or even compatible with, MSVC.
This is fine because they don't generate names that they can use across
translation units. Technically, we can generate any name we'd like so
long as that name wouldn't conflict with any other and would be stable
across translation units.
This fixes PR15512.
llvm-svn: 202962
Summary:
The MSVC ABI appears to mangle the lexical scope into the names of
statics. Specifically, a counter is incremented whenever a scope is
entered where things can be declared in such a way that an ambiguity can
arise. For example, a class scope inside of a class scope doesn't do
anything interesting because the nested class cannot collide with
another nested class.
There are problems with this scheme:
- It is unreliable. The counter is only incremented when a previously
never encountered scope is entered. There are cases where this will
cause ambiguity amongst declarations that have the same name where one
was introduced in a deep scope while the other was introduced right
after in the previous lexical scope.
- It is wasteful. Statements like: {{{{{{{ static int foo = a; }}}}}}}
will make the mangling of "foo" larger than it need be because the
scope counter has been incremented many times.
Because of these problems, and practical implementation concerns. We
choose not to implement this scheme if the local static or local type
isn't visible. The mangling of these declarations will look very
similar but the numbering will make far more sense, this scheme is
lifted from the Itanium ABI implementation.
Reviewers: rsmith, doug.gregor, rnk, eli.friedman, cdavis5x
Reviewed By: rnk
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2953
llvm-svn: 202951
We wouldn't recognize variable templates as being templates leading us
to leave the template arguments off of the mangled name. This would
allow two unrelated templates to map to the same mangled name.
N.B. While MSVC doesn't support variable templates as of this date,
this mangling is the most likely thing they will choose to use. Their
demangler can successfully demangle our manglings with the template
arguments shown.
llvm-svn: 202789
Extended qualifiers can appear in many places, refactor the code so it's
more reusable. Add tests in areas where we've increased compatibility.
llvm-svn: 201574
Pointer types in the MSVC ABI are a bit awkward, the width of the
pointer is considered a kind of CVR qualifier.
Restrict is handled similarly to const and volatile but is mangled after
the pointer width qualifier.
This fixes PR18880.
llvm-svn: 201569
Properly support fields that come from anonymous unions and structs
when used as template arguments for pointer to data member params.
llvm-svn: 200921
Properly determine the inheritance model when dealing with nullptr:
- If a nullptr template argument is being checked against
pointer-to-member parameter, nail down an inheritance model.
N.B. We will chose an inheritance model even if we won't ultimately
choose the template to instantiate! Cooky, right?
- Null pointer-to-datamembers have a virtual base table offset of -1,
not zero. Previously, we chose an offset of 0.
llvm-svn: 200920
Function references always use $1? like function pointers and never $E?
like var decl references. Static methods are mangled like function
pointers.
llvm-svn: 200869
Member pointers are mangled as they would be represented at runtime.
They can be a single integer literal, single decl, or a tuple with some
more numbers tossed in. With Clang today, most of those numbers will be
zero because we reject pointers to members of virtual bases.
This change required moving VTableContextBase ownership from
CodeGenVTables to ASTContext, because mangling now depends on vtable
layout.
I also hoisted the inheritance model helpers up to be inline static
methods of MSInheritanceAttr. This makes the AST code that deals with
member pointers much more readable.
MSVC doesn't appear to have stable manglings of null member pointers:
- Null data memptrs in function templates have a mangling collision with
the first field of a non-polymorphic single inheritance class.
- The mangling of null data memptrs changes if you add casts.
- Large null function memptrs in class templates crash MSVC.
Clang uses the class template mangling for null data memptrs and the
function template mangling for null function memptrs to deal with this.
Reviewers: majnemer
Differential Revision: http://llvm-reviews.chandlerc.com/D2695
llvm-svn: 200857
A return type is the declared or deduced part of the function type specified in
the declaration.
A result type is the (potentially adjusted) type of the value of an expression
that calls the function.
Rule of thumb:
* Declarations have return types and parameters.
* Expressions have result types and arguments.
llvm-svn: 200082
The MSVC C++ ABI always uses the deduced type in place of auto when
generating external names for variables.
N.B. MSVC doesn't support C++1y's 'operator auto' and this patch will
not give us said functionality.
llvm-svn: 199764
Fix a perennial source of confusion in the clang type system: Declarations and
function prototypes have parameters to which arguments are supplied, so calling
these 'arguments' was a stretch even in C mode, let alone C++ where default
arguments, templates and overloading make the distinction important to get
right.
Readability win across the board, especially in the casting, ADL and
overloading implementations which make a lot more sense at a glance now.
Will keep an eye on the builders and update dependent projects shortly.
No functional change.
llvm-svn: 199686
encodes the canonical rules for LLVM's style. I noticed this had drifted
quite a bit when cleaning up LLVM, so wanted to clean up Clang as well.
llvm-svn: 198686
This reverts commit r197184.
Richard Smith brings up some good points, a proper implementation will
require us to mangle unnameable entities compatibly with MSVC.
llvm-svn: 197192
Testing has revealed that large integral constants (i.e. > INT64_MAX)
are always mangled as-if they are negative, even in places where it
would not make sense for them to be negative (like non-type template
parameters of type unsigned long long).
To address this, we change the way we model number mangling: always
mangle as-if our number is an int64_t. This should result in correct
results when we have large unsigned numbers.
N.B. Bizarrely, things that are 32-bit displacements like vbptr offsets
are mangled as-if they are unsigned 32-bit numbers. This is a pretty
egregious waste of space, it would be a 4x savings if we could mangle it
like a signed 32-bit number. Instead, we explicitly cast these
displacements to uint32_t and let the mangler proceed.
llvm-svn: 196771
While testing our ability to mangle large constants (PR18175), I
incidentally discovered that we did not properly mangle enums correctly.
Previously, we would append the width of the enum in bytes after the
type-tag differentiator.
This would mean "enum : short" would be mangled as 'W2' while "enum :
char" would be mangled as 'W1'. Upon testing this with several versions
of MSVC, I found that this did not match their behavior: they always use
'W4'.
N.B. Quick testing uncovered that undname allows different numbers to
follow the 'W' in the following way:
'W0' -> "enum char"
'W1' -> "enum unsigned char"
'W2' -> "enum short"
'W3' -> "enum unsigned short"
'W4' -> "enum"
'W5' -> "enum unsigned int"
'W6' -> "enum long"
'W7' -> "enum unsigned long"
However this scheme appears abandoned, I cannot get MSVC to trigger it.
Furthermore, it's incomplete: it doesn't handle "bool" or "long long".
llvm-svn: 196752
It wasn't possible for an anonymous type to show up inside of function arguments.
However, decltype (which MSVC added support for in 2010) makes this
possible. Further, backrefs to these anonymous types can now be formed.
This fixes PR18022.
N.B. We do not, and very likely _will not_, support MSVC's bug where
subsequent typedefs of anonymous types leak into the linkage name; this
is a gross violation of the ABI. A warning should be introduced to
inform our users of this particular shortcoming.
llvm-svn: 195669
Summary:
RTTI is not yet implemented for the Microsoft C++ ABI and isn't expected
soon. We could easily add the mangling, but the error is what prevents
us from silently miscompiling code that expects RTTI.
Instead, add a new mangleTypeName entry point that simply forwards to
mangleName or mangleType to produce a string that isn't part of the ABI.
Itanium can continue to use RTTI names to avoid unecessary test
breakage.
This also seems like the right design. The fact that TBAA names happen
to be RTTI names is now an implementation detail of the mangler, rather
than part of TBAA.
Differential Revision: http://llvm-reviews.chandlerc.com/D2153
llvm-svn: 195168
Instead of storing the vtable offset directly in the function pointer and
doing a branch to check for virtualness at each call site, the MS ABI
generates a thunk for calling the function at a specific vtable offset,
and puts that in the function pointer.
This patch adds support for emitting such thunks. However, it doesn't support
pointers to virtual member functions that are variadic, have an incomplete
aggregate return type or parameter, or are overriding a function in a virtual
base class.
Differential Revision: http://llvm-reviews.chandlerc.com/D2104
llvm-svn: 194827
This removes the dependency on the llvm mangler doing it for us. In isolation,
the benefit is that the testing of what mangling is applied is all in one place:
(C, C++) X (Itanium, Microsoft) are all handled by clang.
This also gives me hope that in the future the llvm mangler (and llvm-ar) will
not depend on TargetMachine.
llvm-svn: 192762
Summary:
Operator new, new[], delete, and delete[] are all implicitly static when
declared inside a record. CXXMethodDecl already knows this, but we need
to account for that before we pick the calling convention for the
function type.
Fixes PR17371.
Reviewers: rsmith
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1761
llvm-svn: 192150
Summary:
When selecting a mangling for an anonymous tag type:
- We should first try it's typedef'd name.
- If that doesn't work, we should mangle in the name of the declarator
that specified it as a declaration specifier.
- If that doesn't work, fall back to a static mangling of
<unnamed-type>.
This should make our anonymous type mangling compatible.
This partially fixes PR16994; we would need to have an implementation of
scope numbering to get it right (a separate issue).
Reviewers: rnk, rsmith, rjmccall, cdavis5x
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1540
llvm-svn: 190892
Summary:
This fixes several issues with the original implementation:
- Win32 entry points cannot be in namespaces
- A Win32 entry point cannot be a function template, diagnose if we it.
- Win32 entry points cannot be overloaded.
- Win32 entry points implicitly return, similar to main.
Reviewers: rnk, rsmith, whunt, timurrrr
Reviewed By: rnk
CC: cfe-commits, nrieck
Differential Revision: http://llvm-reviews.chandlerc.com/D1683
llvm-svn: 190818
Summary:
Functions named "main", "wmain", "WinMain", "wWinMain", and "DllMain"
are never mangled regardless of linkage, even when compiling for kernel
mode.
Depends on D1655
Reviewers: timurrrr, pcc, rnk, whunt
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1670
llvm-svn: 190675
Summary:
This is a first step to getting extern "C" working properly inside
clang. There are a number of quirks but mangling declarations inside
such a function are a good first step.
Reviewers: timurrrr, pcc, cdavis5x
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1655
llvm-svn: 190671
Summary:
More accurately characterize the nature of array parameters. Doing this
removes false back-reference opportunities. Remove some hacks now that
we characterize these better.
Reviewers: rnk, timurrrr, whunt, cdavis5x
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1626
llvm-svn: 190488
Static locals requiring initialization are not thread safe on Windows.
Unfortunately, it's possible to create static locals that are actually
externally visible with inline functions and templates. As a result, we
have to implement an initialization guard scheme that is compatible with
TUs built by MSVC, which makes thread safety prohibitively difficult.
MSVC's scheme is that every function that requires a guard gets an i32
bitfield. Each static local is assigned a bit that indicates if it has
been initialized, up to 32 bits, at which point a new bitfield is
created. MSVC rejects inline functions with more than 32 static locals,
and the externally visible mangling (?_B) only allows for one guard
variable per function.
On Eli's recommendation, I used MangleNumberingContext to track which
bit each static corresponds to.
Implements PR16888.
Reviewers: rjmccall, eli.friedman
Differential Revision: http://llvm-reviews.chandlerc.com/D1416
llvm-svn: 190427
Summary:
Makes functions with implicit calling convention compatible with
function types with a matching explicit calling convention. This fixes
things like calls to qsort(), which has an explicit __cdecl attribute on
the comparator in Windows headers.
Clang will now infer the calling convention from the declarator. There
are two cases when the CC must be adjusted during redeclaration:
1. When defining a non-inline static method.
2. When redeclaring a function with an implicit or mismatched
convention.
Fixes PR13457, and allows clang to compile CommandLine.cpp for the
Microsoft C++ ABI.
Excellent test cases provided by Alexander Zinenko!
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D1231
llvm-svn: 189412
Summary:
HandleTopLevelDecl on a templated function leads us to try and mangle
it.
Reviewers: rsmith
Reviewed By: rsmith
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1412
llvm-svn: 188536
Summary:
There were several things going wrong:
- We mangled in useless qualifiers like "volatile void" return types.
- We didn't propagate 64-bit pointer markers sufficiently.
- We mangled qualifiers belonging to the pointee incorrectly.
This fixes PR16844 and PR16848.
Reviewers: rnk, whunt
Reviewed By: rnk
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1353
llvm-svn: 188450
Summary:
It seems that __uuidof introduces a global extern "C" declaration of
type __s_GUID. However, our implementation of __uuidof does not provide
such a declaration and thus must open-code the mangling for __uuidof in
template parameters.
This allows us to codegen scoped COM pointers and other such things.
This fixes PR16836.
Depends on D1356.
Reviewers: rnk, cdavis5x, rsmith
Reviewed By: rnk
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1357
llvm-svn: 188252
We mangled them like:
L___uuid_12345678-1234-1234-1234-123456789abc
We should've mangled them like:
__GUID_12345678_1234_1234_1234_123456789abc
Furthermore, they are external symbols.
llvm-svn: 188053
There were three things missing from the original implementation:
- We would omit the 'E' qualifier for members int 64-bit mode.
- We would not exmaine the qualifiers in 'IsMember' mode.
- We didn't generate the correct backref to the base class.
llvm-svn: 187753
Based on Peter Collingbourne's destructor patches.
Prior to this change, clang was considering ?1 to be the complete
destructor and the base destructor, which was wrong. This lead to
crashes when clang tried to emit two LLVM functions with the same name.
In this ABI, TUs with non-inline dtors might not emit a complete
destructor. They are emitted as inline thunks in TUs that need them,
and they always delegate to the base dtors of the complete class and its
virtual bases. This change uses the DeferredDecls machinery to emit
complete dtors as needed.
Currently in clang try body destructors can catch exceptions thrown by
virtual base destructors. In the Microsoft C++ ABI, clang may not have
the destructor definition, in which case clang won't wrap the virtual
virtual base destructor calls in a try-catch. Diagnosing this in user
code is TODO.
Finally, for classes that don't use virtual inheritance, MSVC always
calls the base destructor (?1) directly. This is a useful code size
optimization that avoids emitting lots of extra thunks or aliases.
Implementing it also means our existing tests continue to pass, and is
consistent with MSVC's output.
We can do the same for Itanium by tweaking GetAddrOfCXXDestructor, but
it will require further testing.
Reviewers: rjmccall
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D1066
llvm-svn: 186828
They don't seem to be used for back references, presumably because a
function template is unlikely to reoccur, while a class template name
may reoccur as a type.
This fixes a mangling issue for llvm::hash_combine() in Hashing.h.
Reviewers: timurrrr
Differential Revision: http://llvm-reviews.chandlerc.com/D1078
llvm-svn: 186233
Unlike Itanium, there is no code to indicate the beginning of a
parameter pack. I tested this with MSVC 2013, which is the only version
that implements variadic templates so far.
This is needed to compile APInt.cpp for the MS C++ ABI.
Reviewers: timurrrr
Differential Revision: http://llvm-reviews.chandlerc.com/D1077
llvm-svn: 185454
At this point, it's clear that the MSVC mangler uses the type-as-written
instead of the canonical type, so this should bring us closer to MSVC.
The main thrust of this change is to fix the way we mangle decayed array
parameters of function pointer parameters. With a DecayedType sugar
node, this code can now be much simpler.
Fixes PR16096.
This also fixes a separate issue that Richard spotted in review.
Because separate declarations of the same entity can be spelled and
mangled differently, MSVC always mangles the earliest declaration in an
attempt to avoid link errors. Clang now does the same.
Reviewers: rsmith
Differential Revision: http://llvm-reviews.chandlerc.com/D844
llvm-svn: 184777
In Itanium, dynamic classes have one vtable with several different
address points for dynamic base classes that can't share vtables.
In the MS C++ ABI, each vbtable that can't be shared gets its own
symbol, similar to how ctor vtables work in Itanium. However, instead
of mangling the subobject offset into the symbol, the unique portions of
the inheritance path are mangled into the symbol to make it unique.
This patch implements the MSVC 2012 scheme for forming unique vbtable
symbol names. MSVC 2010 use the same mangling with a different subset
of the path. Implementing that mangling and possibly others is TODO.
Each vbtable is an array of i32 offsets from the vbptr that points to it
to another virtual base subobject. The first entry of a vbtable always
points to the base of the current subobject, implying that it is the
same no matter which parent class contains it.
Reviewers: rjmccall
Differential Revision: http://llvm-reviews.chandlerc.com/D636
llvm-svn: 184309
Most of the complexity of this patch is figuring out which types get the
qualifier and which don't. If we implement __ptr32/64, then we should
check the qualifier instead of assuming all pointers are 64-bit.
This fixes PR13792.
Patch by Warren Hunt!
llvm-svn: 181825
This patch renames getLinkage to getLinkageInternal. Only code that
needs to handle UniqueExternalLinkage specially should call this.
Linkage, as defined in the c++ standard, is provided by
getFormalLinkage. It maps UniqueExternalLinkage to ExternalLinkage.
Most places in the compiler actually want isExternallyVisible, which
handles UniqueExternalLinkage as internal.
llvm-svn: 181677
EmitCapturedStmt creates a captured struct containing all of the captured
variables, and then emits a call to the outlined function. This is similar in
principle to EmitBlockLiteral.
GenerateCapturedFunction actually produces the outlined function. It is based
on GenerateBlockFunction, but is much simpler. The function type is determined
by the parameters that are in the CapturedDecl.
Some changes have been added to this patch that were reviewed as part of the
serialization patch and moving the parameters to the captured decl.
Differential Revision: http://llvm-reviews.chandlerc.com/D640
llvm-svn: 181536
This includes the following fixes:
- Implement 4 subtly different variants of qualifier mangling and use them
in what I believe are the right places.
- Fix handling of array types. Previously we were always decaying them,
which is wrong if the type appears as a template argument, pointee,
referent etc.
Fixes PR13182.
Differential Revision: http://llvm-reviews.chandlerc.com/D709
llvm-svn: 180250
Summary:
The only vector types a user can pass from MSVC code to clang code are
the ones from *mmintrin.h, so we only have to match the MSVC mangling
for these types. MSVC mangles the __m128 family of types as tag types,
which we match. For other vector types, we emit a unique tag type
mangling that won't match anything produced by MSVC.
Reviewers: rjmccall
CC: chandlerc, timurrrr, cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D576
llvm-svn: 178036
This code was changed in r158376 to get template argument source info
for better diagnostics, but the current code asserts for any kind of
unsupported template argument before it can issue a diagnostic. This change
goes back to the Itanium implementation of isTemplate() and puts the argument
index into the diagnostic instead of a source location.
Review URL: http://llvm-reviews.chandlerc.com/D553
llvm-svn: 177471
The TypeLoc hierarchy used the llvm::cast machinery to perform undefined
behavior by casting pointers/references to TypeLoc objects to derived types
and then using the derived copy constructors (or even returning pointers to
derived types that actually point to the original TypeLoc object).
Some context is in this thread:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2012-December/056804.html
Though it's spread over a few months which can be hard to read in the mail
archive.
llvm-svn: 175462
GCC 4.7 reuses stack slots fairly aggressively, which exposes more temporary
lifetime bugs.
No new test, this was caught by the existing CodeGenCXX/mangle-ms-templates.cpp.
llvm-svn: 168124
Integer literal mangling does not actually depend on exact type of the literal.
This will simplify calling mangleIntegerLiteral when literal type is not known,
for example, when sizes or offsets are mangled as integer literals.
Also, call mangleNumber instead of directly printing mangled values of 0/1, to
avoid this knowledge from being in multiple places.
Patch from Evgeny Eltsin!
llvm-svn: 167878
