When implementing `@objcDirect` in Swift, Swift needs to mangle a native
`Decl` that is not a clang Node, which in turn don't have access to
`clang::MangleContext`. Reimplementing mangling logic in Swift is
redundant.
This patch moves mangling logic from `clang::MangleContext` to `clang`
using only basic types (`StringRef`, `std::optional`, etc.), such that
Swift can we can just call Clang API: Swift depends on Clang already.
We are separating this from #126639 so we can draft the proposal on the
Swift side. #126639 will be worked to depend on this PR.
Tests: No new tests, old ones should pass with no problem.
---------
Signed-off-by: Peter Rong <PeterRong@meta.com>
When given an invalid Objective-C extension, Clang would crash when
trying to emit the mangled name of the method to the JSON dump output.
Fixes#137320
This feature is currently not supported in the compiler.
To facilitate this we emit a stub version of each kernel
function body with different name mangling scheme, and
replaces the respective kernel call-sites appropriately.
Fixes https://github.com/llvm/llvm-project/issues/60313
D120566 was an earlier attempt made to upstream a solution
for this issue.
---------
Co-authored-by: anikelal <anikelal@amd.com>
* Don't call raw_string_ostream::flush(), which is essentially a no-op.
* Strip unneeded calls to raw_string_ostream::str(), to avoid extra indirection.
Virtual function pointer entries in v-tables are signed with address
discrimination in addition to declaration-based discrimination, where an
integer discriminator the string hash (see
`ptrauth_string_discriminator`) of the mangled name of the overridden
method. This notably provides diversity based on the full signature of
the overridden method, including the method name and parameter types.
This patch introduces ItaniumVTableContext logic to find the original
declaration of the overridden method.
On AArch64, these pointers are signed using the `IA` key (the
process-independent code key.)
V-table pointers can be signed with either no discrimination, or a
similar scheme using address and decl-based discrimination. In this
case, the integer discriminator is the string hash of the mangled
v-table identifier of the class that originally introduced the vtable
pointer.
On AArch64, these pointers are signed using the `DA` key (the
process-independent data key.)
Not using discrimination allows attackers to simply copy valid v-table
pointers from one object to another. However, using a uniform
discriminator of 0 does have positive performance and code-size
implications on AArch64, and diversity for the most important v-table
access pattern (virtual dispatch) is already better assured by the
signing schemas used on the virtual functions. It is also known that
some code in practice copies objects containing v-tables with `memcpy`,
and while this is not permitted formally, it is something that may be
invasive to eliminate.
This is controlled by:
```
-fptrauth-vtable-pointer-type-discrimination
-fptrauth-vtable-pointer-address-discrimination
```
In addition, this provides fine-grained controls in the
ptrauth_vtable_pointer attribute, which allows overriding the default
ptrauth schema for vtable pointers on a given class hierarchy, e.g.:
```
[[clang::ptrauth_vtable_pointer(no_authentication, no_address_discrimination,
no_extra_discrimination)]]
[[clang::ptrauth_vtable_pointer(default_key, default_address_discrimination,
custom_discrimination, 0xf00d)]]
```
The override is then mangled as a parametrized vendor extension:
```
"__vtptrauth" I
<key>
<addressDiscriminated>
<extraDiscriminator>
E
```
To support this attribute, this patch adds a small extension to the
attribute-emitter tablegen backend.
Note that there are known areas where signing is either missing
altogether or can be strengthened. Some will be addressed in later
changes (e.g., member function pointers, some RTTI).
`dynamic_cast` in particular is handled by emitting an artificial
v-table pointer load (in a way that always authenticates it) before the
runtime call itself, as the runtime doesn't have enough information
today to properly authenticate it. Instead, the runtime is currently
expected to strip the v-table pointer.
---------
Co-authored-by: John McCall <rjmccall@apple.com>
Co-authored-by: Ahmed Bougacha <ahmed@bougacha.org>
This patch replaces uses of StringRef::{starts,ends}with with
StringRef::{starts,ends}_with for consistency with
std::{string,string_view}::{starts,ends}_with in C++20.
I'm planning to deprecate and eventually remove
StringRef::{starts,ends}with.
Mixing LLVM and Clang address spaces can result in subtle bugs, and there
is no need for this hook to use the LLVM IR level address spaces.
Most of this change is just replacing zero with LangAS::Default,
but it also allows us to remove a few calls to getTargetAddressSpace().
This also removes a stale comment+workaround in
CGDebugInfo::CreatePointerLikeType(): ASTContext::getTypeSize() does
return the expected size for ReferenceType (and handles address spaces).
Differential Revision: https://reviews.llvm.org/D138295
Semantic parameters aren't passed as actual parameters, instead they are
populated from intrinsics which are generally lowered to reads from
dedicated hardware registers.
This change modifies clang CodeGen to emit the intrinsic calls and
populate the parameter's LValue with the result of the intrinsic call
for SV_GroupIndex.
The result of this is to make the actual passed argument ignored, which
will make it easy to clean up later in an IR pass.
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D131203
Remove the `hasPrototype()` restriction so that old style K&R
declarations of main work too.
For example the following has 2 params but no prototype.
```
int main(argc, argv)
int argc;
char *argv[];
{
return 0;
}
```
Also, use `getNumParams()` over `param_size()` which seems to be a more
direct way to get at the same information.
Also, add missing tests for this mangling.
Differential Revision: https://reviews.llvm.org/D127888
stdcall name mangling requires a suffix with the number equal to the sum of the byte count of all parameter types. In the case of a function prototype that has a parameter type of an incomplete type it is impossible to get the size of the type. While such a function is not callable or able to be defined in the TU, it may still be mangled when generating debug info, which would previously lead to a crash.
This patch fixes that by simply bailing out of the loop and using the so far accumulated byte count. This matches GCCs behaviour as well: bc8d6c6013/gcc/config/i386/winnt.c (L203)
Fixes https://github.com/llvm/llvm-project/issues/52782
Differential Revision: https://reviews.llvm.org/D116020
Reverts parts of https://reviews.llvm.org/D17183, but keeps the
resetDataLayout() API and adds an assert that checks that datalayout string and
user label prefix are in sync.
Approach 1 in https://reviews.llvm.org/D17183#2653279
Reduces number of TUs build for 'clang-format' from 689 to 575.
I also implemented approach 2 in D100764. If someone feels motivated
to make us use DataLayout more, it's easy to revert this change here
and go with D100764 instead. I don't plan on doing more work in this
area though, so I prefer going with the smaller, more self-consistent change.
Differential Revision: https://reviews.llvm.org/D100776
The option -funique-internal-linkage-names was added in D73307 and D78243 as a
LLVM early pass to insert a unique suffix to internal linkage functions and
vars. The unique suffix was the hash of the module path. However, we found
that this can be done more cleanly in clang early and the fixes that need to
be done later can be completely avoided. The fixes in particular are trying
to modify the DW_AT_linkage_name and finding the right place to insert the
pass.
This patch ressurects the original implementation proposed in D73307 which
was reviewed and then ditched in favor of the pass based approach.
Differential Revision: https://reviews.llvm.org/D96109
- Fix a memory leak accidentally introduced yesterday by using CodeGen's
existing mangling context instead of creating a new context afresh.
- Move GNU-runtime ObjC method mangling into the AST mangler; this will
eventually be necessary to support direct methods there, but is also
just the right architecture.
- Make the Apple-runtime method mangling work properly when given an
interface declaration, fixing a bug (which had solidified into a test)
where mangling a category method from the interface could cause it to
be mangled as if the category name was a class name. (Category names
are namespaced within their class and have no global meaning.)
- Fix a code cross-reference in dsymutil.
Based on a patch by Ellis Hoag.
Summary:
Previously, we treated CXXUuidofExpr as quite a special case: it was the
only kind of expression that could be a canonical template argument, it
could be a constant lvalue base object, and so on. In addition, we
represented the UUID value as a string, whose source form we did not
preserve faithfully, and that we partially parsed in multiple different
places.
With this patch, we create an MSGuidDecl object to represent the
implicit object of type 'struct _GUID' created by a UuidAttr. Each
UuidAttr holds a pointer to its 'struct _GUID' and its original
(as-written) UUID string. A non-value-dependent CXXUuidofExpr behaves
like a DeclRefExpr denoting that MSGuidDecl object. We cache an APValue
representation of the GUID on the MSGuidDecl and use it from constant
evaluation where needed.
This allows removing a lot of the special-case logic to handle these
expressions. Unfortunately, many parts of Clang assume there are only
a couple of interesting kinds of ValueDecl, so the total amount of
special-case logic is not really reduced very much.
This fixes a few bugs and issues:
* PR38490: we now support reading from GUID objects returned from
__uuidof during constant evaluation.
* Our Itanium mangling for a non-instantiation-dependent template
argument involving __uuidof no longer depends on which CXXUuidofExpr
template argument we happened to see first.
* We now predeclare ::_GUID, and permit use of __uuidof without
any header inclusion, better matching MSVC's behavior. We do not
predefine ::__s_GUID, though; that seems like a step too far.
* Our IR representation for GUID constants now uses the correct IR type
wherever possible. We will still fall back to using the
{i32, i16, i16, [8 x i8]}
layout if a definition of struct _GUID is not available. This is not
ideal: in principle the two layouts could have different padding.
Reviewers: rnk, jdoerfert
Subscribers: arphaman, cfe-commits, aeubanks
Tags: #clang
Differential Revision: https://reviews.llvm.org/D78171
Summary:
- https://reviews.llvm.org/D68578 revises the `GlobalDecl` constructors
to ensure all GPU kernels have `ReferenceKenelKind` initialized
properly with an explicit constructor and static one. But, there are
lots of places using the implicit constructor triggering the assertion
on non-GPU kernels. That's found in compilation of many tests and
workloads.
- Fixing all of them may change more code and, more importantly, all of
them assumes the default kernel reference kind. This patch changes
that constructor to tell `CUDAGlobalAttr` and construct `GlobalDecl`
properly.
Reviewers: yaxunl
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D76344
HIP emits a device stub function for each kernel in host code.
The HIP debugger requires device stub function to have a different unmangled name as the kernel.
Currently the name of the device stub function is the mangled name with a postfix .stub. However,
this does not work with the HIP debugger since the unmangled name is the same as the kernel.
This patch adds prefix __device__stub__ to the unmangled name of the device stub before mangling,
therefore the device stub function has a valid mangled name which is different than the device kernel
name. The device side kernel name is kept unchanged. kernels with extern "C" also gets the prefix added
to the corresponding device stub function.
Differential Revision: https://reviews.llvm.org/D68578
WebAssembly enforces a rule that caller and callee signatures must
match. This means that the traditional technique of passing `main`
`argc` and `argv` even when it doesn't need them doesn't work.
Currently the backend renames `main` to `__original_main`, however this
doesn't interact well with LTO'ing libc, and the name isn't intuitive.
This patch allows us to transition to `__main_argc_argv` instead.
This implements the proposal in
https://github.com/WebAssembly/tool-conventions/pull/134
with a flag to disable it when targeting Emscripten, though this is
expected to be temporary, as discussed in the proposal comments.
Differential Revision: https://reviews.llvm.org/D70700
This is how it should've been and brings it more in line with
std::string_view. There should be no functional change here.
This is mostly mechanical from a custom clang-tidy check, with a lot of
manual fixups. It uncovers a lot of minor inefficiencies.
This doesn't actually modify StringRef yet, I'll do that in a follow-up.
The static analyzer is warning about potential null dereferences, but in these cases we should be able to use castAs<> directly and if not assert will fire for us.
llvm-svn: 373904
LLDB synthesizes decls using asm labels. These decls cannot have a mangle
different than the one specified in the label name. I.e., the '\01' prefix
should not be added.
Fixes an expression evaluation failure in lldb's TestVirtual.py on iOS.
rdar://45827323
Differential Revision: https://reviews.llvm.org/D67774
llvm-svn: 372903
Now that we've moved to C++14, we no longer need the llvm::make_unique
implementation from STLExtras.h. This patch is a mechanical replacement
of (hopefully) all the llvm::make_unique instances across the monorepo.
Differential revision: https://reviews.llvm.org/D66259
llvm-svn: 368942
The original pimpl pattern used between CodegenNameGenerator and
CodegenNameGeneratorImpl did a good job of hiding DataLayout making it so that
users of CodegenNameGenerator did not need to link with llvm core. This is an
NFC change to neatly wrap ASTNameGenerator in a pimpl.
Differential Revision: https://reviews.llvm.org/D63584
llvm-svn: 363908
This is a NFC refactor move of CodegenNameGeneratorImpl from clang::Index to
clang:AST (and rename to ASTNameGenerator). The purpose is to make the
highlevel mangling code more reusable inside of clang (say in places like clang
FrontendAction). This does not affect anything in CodegenNameGenerator, except
that CodegenNameGenerator will now use ASTNameGenerator (in AST).
Differential Revision: https://reviews.llvm.org/D63535
llvm-svn: 363878
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
This hasn't even compiled since 2011. It would be useful to have some test to
verify that ItaniumMangle and ItaniumDemangle agree, but this isn't it.
llvm-svn: 345075
This patch implements the register call calling convention, which ensures
as many values as possible are passed in registers. CodeGen changes
were committed in https://reviews.llvm.org/rL284108.
Differential Revision: https://reviews.llvm.org/D25204
llvm-svn: 285849
Use it to calculate UserLabelPrefix, instead of specifying it (often
incorrectly).
Note that the *actual* user label prefix has always come from the
DataLayout, and is handled within LLVM. The main thing clang's
TargetInfo::UserLabelPrefix did was to set the #define value. Having
these be different from each-other is just silly.
Differential Revision: http://reviews.llvm.org/D17183
llvm-svn: 262737
After r244870 flush() will only compare two null pointers and return,
doing nothing but wasting run time. The call is not required any more
as the stream and its SmallString are always in sync.
Thanks to David Blaikie for reviewing.
llvm-svn: 244928
