By exposing the constant initializer, the optimizer can fold many
of these constructs.
This is a recommit of r311857 that was reverted in r311898 because
an assert was hit when building Chromium.
We have to take into account that the GlobalVariable may be first
created with a different type than the initializer. This can
happen for example when the variable is a struct with tail padding
while the initializer does not have padding. In such case, the
variable needs to be destroyed an replaced with a new one with the
type of the initializer.
Differential Revision: https://reviews.llvm.org/D34992
llvm-svn: 312512
This fixes cases where dynamic classes produced RTTI data with
external linkage, producing linker errors about duplicate symbols.
This touches code close to what was changed in SVN r244266, but
this change doesn't break the tests added in that revision.
The previous version had missed to update CodeGenCXX/virt-dtor-key.cpp,
which had a behaviour change only when running the testsuite on windows.
Differential revision: https://reviews.llvm.org/D37327
llvm-svn: 312306
This fixes cases where dynamic classes produced RTTI data with
external linkage, producing linker errors about duplicate symbols.
This touches code close to what was changed in SVN r244266, but
this change doesn't break the tests added in that revision.
Differential revision: https://reviews.llvm.org/D37206
llvm-svn: 312224
Overriding a method from a virtual base with a covariant return type
consumes a slot from the vftable in the virtual base. This can make it
impossible to implement certain diamond inheritance hierarchies, but we
have to follow along for compatibility in the simple cases.
This patch only affects our vtable dumper and member pointer function
mangling, since all other callers of getMethodVFTableLocation seem to
recompute VBTableIndex instead of using the one in the method location.
Patch by David Majnemer
llvm-svn: 312017
It caused PR759744.
> Emit static constexpr member as available_externally definition
>
> By exposing the constant initializer, the optimizer can fold many
> of these constructs.
>
> Differential Revision: https://reviews.llvm.org/D34992
llvm-svn: 311898
By exposing the constant initializer, the optimizer can fold many
of these constructs.
Differential Revision: https://reviews.llvm.org/D34992
llvm-svn: 311857
This patch adds a flag -fclang-abi-compat that can be used to request that
Clang attempts to be ABI-compatible with some older version of itself.
This is provided on a best-effort basis; right now, this can be used to undo
the ABI change in r310401, reverting Clang to its prior C++ ABI for pass/return
by value of class types affected by that change, and to undo the ABI change in
r262688, reverting Clang to using integer registers rather than SSE registers
for passing <1 x long long> vectors. The intent is that we will maintain this
backwards compatibility path as we make ABI-breaking fixes in future.
The reversion to the old behavior for r310401 is also applied to the PS4 target
since that change is not part of its platform ABI (which is essentially to do
whatever Clang 3.2 did).
llvm-svn: 311823
expressions
C++ allows us to reference static variables through member expressions. Prior to
this commit, non-integer static variables that were referenced using a member
expression were always emitted using lvalue loads. The old behaviour introduced
an inconsistency between regular uses of static variables and member expressions
uses. For example, the following program compiled and linked successfully:
struct Foo {
constexpr static const char *name = "foo";
};
int main() {
return Foo::name[0] == 'f';
}
but this program failed to link because "Foo::name" wasn't found:
struct Foo {
constexpr static const char *name = "foo";
};
int main() {
Foo f;
return f.name[0] == 'f';
}
This commit ensures that constant static variables referenced through member
expressions are emitted in the same way as ordinary static variable references.
rdar://33942261
Differential Revision: https://reviews.llvm.org/D36876
llvm-svn: 311772
Do not sanitize the 'this' pointer of a member call operator for a lambda with
no capture-default, since that call operator can legitimately be called with a
null this pointer from the static invoker function. Any actual call with a null
this pointer should still be caught in the caller (if it is being sanitized).
This reinstates r311589 (reverted in r311680) with the above fix.
llvm-svn: 311695
Summary:
Most DIExpressions are empty or very simple. When they are complex, they
tend to be unique, so checking them inline is reasonable.
This also avoids the need for CodeGen passes to append to the
llvm.dbg.mir named md node.
See also PR22780, for making DIExpression not be an MDNode.
Reviewers: aprantl, dexonsmith, dblaikie
Subscribers: qcolombet, javed.absar, eraman, hiraditya, llvm-commits
Differential Revision: https://reviews.llvm.org/D37075
llvm-svn: 311594
constructors when deciding whether classes should be passed indirectly.
This fixes ABI differences between Clang and GCC:
* Previously, Clang ignored the move constructor when making this
determination. It now takes the move constructor into account, per
https://github.com/itanium-cxx-abi/cxx-abi/pull/17 (this change may
seem recent, but the ABI change was agreed on the Itanium C++ ABI
list a long time ago).
* Previously, Clang's behavior when the copy constructor was deleted
was unstable -- depending on whether the lazy declaration of the
copy constructor had been triggered, you might get different behavior.
We now eagerly declare the copy constructor whenever its deletedness
is unclear, and ignore deleted copy/move constructors when looking for
a trivial such constructor.
This also fixes an ABI difference between Clang and MSVC:
* If the copy constructor would be implicitly deleted (but has not been
lazily declared yet), for instance because the class has an rvalue
reference member, we would pass it directly. We now pass such a class
indirectly, matching MSVC.
Based on a patch by Vassil Vassilev, which was based on a patch by Bernd
Schmidt, which was based on a patch by Reid Kleckner!
This is a re-commit of r310401, which was reverted in r310464 due to ARM
failures (which should now be fixed).
llvm-svn: 310983
the class becoming complete and its inline methods being parsed.
This replaces the hack of using the "late parsed template" flag to track member
functions with bodies we've not parsed yet; instead we now use the "will have
body" flag, which carries the desired implication that the function declaration
*is* a definition, and that we've just not parsed its body yet.
llvm-svn: 310776
It was timing out on this test, but for reasons unrelated to the
specific bug it was testing for. Randomly breaking in gdb with `clang
-target i686-windows -fmsc-version=1700` reveals *many* frames from
MicrosoftCXXNameMangler. So, it would seem that some caching is needed
there, as well...
Fingers crossed that specifying a triple is sufficient to work around
this.
llvm-svn: 310444
This is a follow-up to r310436 with actual functional changes. Please
see that commit message for a description of why a cache is appearing
here.
Suggestions for less-bad ways of testing this are appreciated. :)
This fixes PR29160.
llvm-svn: 310437
Converting a _Complex type to a real one simply discards the imaginary part.
This can easily lead to loss of information so for safety (and GCC
compatibility) this patch disallows that when the conversion would be implicit.
The one exception is bool, which actually compares both real and imaginary
parts and so is safe.
llvm-svn: 310427
Previously we limited ourselves to only emitting nested classes, but we
need other kinds of types as well.
This fixes the Visual Studio STL visualizers, so that users can
visualize std::string and other objects.
llvm-svn: 310410
constructors when deciding whether classes should be passed indirectly.
This fixes ABI differences between Clang and GCC:
* Previously, Clang ignored the move constructor when making this
determination. It now takes the move constructor into account, per
https://github.com/itanium-cxx-abi/cxx-abi/pull/17 (this change may
seem recent, but the ABI change was agreed on the Itanium C++ ABI
list a long time ago).
* Previously, Clang's behavior when the copy constructor was deleted
was unstable -- depending on whether the lazy declaration of the
copy constructor had been triggered, you might get different behavior.
We now eagerly declare the copy constructor whenever its deletedness
is unclear, and ignore deleted copy/move constructors when looking for
a trivial such constructor.
This also fixes an ABI difference between Clang and MSVC:
* If the copy constructor would be implicitly deleted (but has not been
lazily declared yet), for instance because the class has an rvalue
reference member, we would pass it directly. We now pass such a class
indirectly, matching MSVC.
llvm-svn: 310401
In r309007, I made -fsanitize=null a hard prerequisite for -fsanitize=vptr. I
did not see the need for the two checks to have separate null checking logic
for the same pointer. I expected the two checks to either always be enabled
together, or to be mutually compatible.
In the mailing list discussion re: r309007 it became clear that that isn't the
case. If a codebase is -fsanitize=vptr clean but not -fsanitize=null clean,
it's useful to have -fsanitize=vptr emit its own null check. That's what this
patch does: with it, -fsanitize=vptr can be used without -fsanitize=null.
Differential Revision: https://reviews.llvm.org/D36112
llvm-svn: 309846
Summary:
Change the condition of this unnecessary packed warning. The packed is unnecessary when
1. the alignment of the struct/class won't alter.
2. the size is unchanged.
3. the offset of each field is the same.
Remove all field-level warning.
Reviewers: chh, akyrtzi, rtrieu
Reviewed By: chh
Subscribers: rsmith, srhines, cfe-commits, xazax.hun
Differential Revision: https://reviews.llvm.org/D34114
llvm-svn: 309750
CodeGenFunction::EmitTypeMetadataCodeForVCall() could output an
llvm.assume(llvm.type.test())when CFI was enabled, optimizing out the
vcall check. This case was only reached when: 1) CFI-vcall was enabled,
2) -fwhole-program-tables was specified, and 3)
-fno-sanitize-trap=cfi-vcall was specified.
Patch by Vlad Tsyrklevich!
Differential Revision: https://reviews.llvm.org/D36013
llvm-svn: 309622
r303175 made changes to have __cxa_allocate_exception return a 16-byte
aligned pointer, so it's no longer necessary to specify a lower
alignment (8-bytes) for exception objects on Darwin.
rdar://problem/32363695
llvm-svn: 309308
The initializer for a static local variable cannot be hot, because it runs at
most once per program. That's not quite the same thing as having a low branch
probability, but under the assumption that the function is invoked many times,
modeling this as a branch probability seems reasonable.
For TLS variables, the situation is less clear, since the initialization side
of the branch can run multiple times in a program execution, but we still
expect initialization to be rare relative to non-initialization uses. It would
seem worthwhile to add a PGO counter along this path to make this estimation
more accurate in future.
For globals with guarded initialization, we don't yet apply any branch weights.
Due to our use of COMDATs, the guard will be reached exactly once per DSO, but
we have no idea how many DSOs will define the variable.
llvm-svn: 309195
std::byte, when defined as an enum, needs to be given special treatment
with regards to its aliasing properties. An array of std::byte is
allowed to be used as storage for other types.
This fixes PR33916.
Differential Revision: https://reviews.llvm.org/D35824
llvm-svn: 309058
The instrumentation generated by -fsanitize=vptr does not null check a
user pointer before loading from it. This causes crashes in the face of
UB member calls (this=nullptr), i.e it's causing user programs to crash
only after UBSan is turned on.
The fix is to make run-time null checking a prerequisite for enabling
-fsanitize=vptr, and to then teach UBSan to reuse these run-time null
checks to make -fsanitize=vptr safe.
Testing: check-clang, check-ubsan, a stage2 ubsan-enabled build
Differential Revision: https://reviews.llvm.org/D35735https://bugs.llvm.org/show_bug.cgi?id=33881
llvm-svn: 309007
Under Windows Itanium, we need to export virtual and non-virtual thunks
if the functions being thunked are exported. These thunks would
previously inherit their dllexport attribute from the declaration, but
r298330 changed declarations to not have dllexport attributes. We
therefore need to add the dllexport attribute to the definition
ourselves now. This is consistent with MinGW GCC's behavior.
This redoes r306770 but limits the logic to Itanium. MicrosoftCXXABI's
setThunkLinkage ensures that thunks aren't exported under that ABI, so
I'm handling this in ItaniumCXXABI's setThunkLinkage for symmetry.
We need to export these thunks because they can be referenced outside
the library they're defined in. For example, if a child class without a
key function inherits from a parent class with a key function, the
parent's thunks will only be defined in the library with the key
function, but the construction vtable for the parent in the child might
be emitted outside the library (since the child doesn't have a key
function), and it needs to reference the parent's thunks.
We don't need to mark these thunks as imported since any references to
them will occur in data, so the compiler can't generate the IAT load
sequence anyway. Instead, we rely on the linker generating import thunks
for the thunks.
Differential Revision: https://reviews.llvm.org/D34972
llvm-svn: 308899
This change is part of the RegCall calling convention support for LLVM.
Existing RegCall implementation was extended to include correct handling of
Complex Long Double type. Complex long double types should be returned/passed
in memory and not register stack. This patch implements this behavior.
Patch by: eandrews
Differential Revision: https://reviews.llvm.org/D35259
llvm-svn: 308769
The uses of alloca may be in different blocks other than the block containing the alloca.
Therefore if the alloca addr space is non-zero and it needs to be casted to default
address space, the cast needs to be inserted in the same BB as the alloca insted of
the current builder insert point since the current insert point may be in a different BB.
Differential Revision: https://reviews.llvm.org/D35438
llvm-svn: 308313
devirtualized.
The code to detect devirtualized calls is already in IRGen, so move the
code to lib/AST and make it a shared utility between Sema and IRGen.
This commit fixes a linkage error I was seeing when compiling the
following code:
$ cat test1.cpp
struct Base {
virtual void operator()() {}
};
template<class T>
struct Derived final : Base {
void operator()() override {}
};
Derived<int> *d;
int main() {
if (d)
(*d)();
return 0;
}
rdar://problem/33195657
Differential Revision: https://reviews.llvm.org/D34301
llvm-svn: 307883
Certain targets (e.g. amdgcn) require global variable to stay in global or constant address
space. In C or C++ global variables are emitted in the default (generic) address space.
This patch introduces virtual functions TargetCodeGenInfo::getGlobalVarAddressSpace
and TargetInfo::getConstantAddressSpace to handle this in a general approach.
It only affects IR generated for amdgcn target.
Differential Revision: https://reviews.llvm.org/D33842
llvm-svn: 307470
Benjamin Kramer