Sometimes the MS ABI needs to emit thunks for declarations that don't
have bodies. Destructor thunks make calls to inlinable functions, so
they need line info or LLVM will complain.
Fixes PR31893
llvm-svn: 294465
Guard against a null pointer dereference that caused Clang to crash
when processing a class containing an _Atomic qualified data member,
and that is tagged with 'dllexport'.
Differential Revision: https://reviews.llvm.org/D29208
llvm-svn: 293911
For non-template dllimport functions, MSVC allows providing an inline
definition without spelling out the attribute again. In the example below, f
remains a dllimport function.
__declspec(dllimport) int f();
inline int f() { return 42; }
int useit() {
return f();
}
However, for a function template, not putting dllimport on the redeclaration
causes it to be dropped. In the example below, f is not dllimport.
template <typename> __declspec(dllimport) int f();
template <typename> inline int f() { return 42; }
int useit() {
return f<int>();
}
This patch makes Clang match MSVC for the second example.
MSVC does not warn about the attribute being dropped in the example above, but
I think we should. (MSVC does warn if the inline keyword isn't used.)
Differential Revision: https://reviews.llvm.org/D29152
llvm-svn: 293800
clang-cl would evaluate the arguments right-to-left (see PR), and for
non-Windows targets I suppose we only got it because we were already
emitting left-to-right in CodeGenFunction::EmitCallArgs.
Differential Revision: https://reviews.llvm.org/D29350
llvm-svn: 293732
The Module::WithCodegen flag was only being set when the module was
parsed from a ModuleMap. Instead set it late, in the ASTWriter to match
the layer where the MODULAR_CODEGEN_DECLs list is determined (the
WithCodegen flag essentially means "are this module's decls in
MODULAR_CODEGEN_DECLs").
When simultaneous emission of AST file and modular object is implemented
this may need to change - the Module::WithCodegen flag will need to be
set earlier, and ideally the MODULAR_CODEGEN_DECLs gathering will
consult this flag (that's not possible right now since Decls destined
for an AST File don't have a Module - only if they're /read/ from a
Module is that true - I expect that would need to change as well).
llvm-svn: 293692
Accounts for a case that caused an assertion failure by attempting to
query for the vtable linkage of a non-dynamic type.t
This reverts commit r292801.
llvm-svn: 293462
As Mehdi put it, entities should either be
available_externally+weak_odr, or linkonce_odr+linkonce_odr. While some
functions are emitted a_e/weak, their local variables were emitted
a_e/linkonce_odr.
While it might be nice to emit them a_e/weak, the Itanium ABI (& best
guess at MSVC's behavior as well) requires the local to be
linkonce/linkonce.
Reviewers: rsmith, mehdi_amini
Differential Revision: https://reviews.llvm.org/D29233
llvm-svn: 293344
Summary:
This reverts commit r292662.
This change broke internal builds. Will provide a reproducer internally.
Subscribers: pcc, mehdi_amini, cfe-commits, mgorny
Differential Revision: https://reviews.llvm.org/D29025
llvm-svn: 292791
To ensure optimization level doesn't pessimize the -fstandalone-debug
vtable debug info optimization (where class definitions are only emitted
where the vtable is emitted - reducing redundant debug info) ensure the
debug info class definition is still omitted when an
available_externally vtable definition is emitted for optimization
purposes.
llvm-svn: 292768
by providing a memchr builtin that returns char* instead of void*.
Also add a __has_feature flag to indicate the presence of constexpr forms of
the relevant <string> functions.
llvm-svn: 292555
In ThinLTO mode, type metadata will require the module to be written as a
multi-module bitcode file, which is currently incompatible with the Darwin
linker. It is also useful to be able to enable or disable multi-module bitcode
for testing purposes. This introduces a cc1-level flag, -f{,no-}lto-unit,
which is used by the driver to enable multi-module bitcode on all but
Darwin+ThinLTO, and can also be used to enable/disable the feature manually.
Differential Revision: https://reviews.llvm.org/D28877
llvm-svn: 292448
Using the canonical type instead of the equivalent type can result in
insufficient template instantiations.
This fixes PR31656.
Differential Revision: https://reviews.llvm.org/D28788
llvm-svn: 292194
This comes up in V8, which has a Handle template class that wraps a
typed pointer, and is frequently passed by value. The pointer is stored
in the base, HandleBase. This change allows us to pass the struct as a
pointer instead of using byval. This avoids creating tons of temporary
allocas that we copy from during call lowering.
Eventually, it would be good to use FCAs here instead.
llvm-svn: 291917
In the case where the template class itself is already `dllexport`, the
implicit instantiation will have already emitted all members. When we
check the explicit instantiation definition, the `Specialization` will
have inherited the `dllexport` attribute, so we'll attempt to emit all
members for a second time, which causes an assertion failure. Restrict
the exporting to when the `dllexport` attribute is newly introduced by
the explicit instantiation definition.
Fixes PR31608.
Differential Revision: https://reviews.llvm.org/D28590
llvm-svn: 291877
* Do not initialize these variables when initializing the rest of the
thread_locals in the TU; they have unordered initialization so they can be
initialized by themselves.
This fixes a rejects-valid bug: we would make the per-variable initializer
function internal, but put it in a comdat keyed off the variable, resulting
in link errors when the comdat is selected from a different TU (as the per
TU TLS init function tries to call an init function that does not exist).
* On Darwin, when we decide that we're not going to emit a thread wrapper
function at all, demote its linkage to External. Fixes a verifier failure
on explicit instantiation of a thread_local variable on Darwin.
llvm-svn: 291865
Fix crash if __FUNCSIG__ is used in a function without a prototype, and use
"(void)" as parameter list instead of "()" for a function with a no-parameters
prototype, matching MSVC's observed behavior.
llvm-svn: 291484
Summary:
Per https://wg21.link/CWG1677, the C++11 standard did not clarify that constant
initialization of an object allowed constexpr brace-or-equal initialization of
subobjects:
struct foo_t { union { int i; volatile int j; } u; };
__attribute__((__require_constant_initialization__))
static const foo_t x = {{0}};
Because foo_t::u has a volatile member, the initializer for x fails. However,
there is really no good reason, because this:
union foo_u { int i; volatile int j; };
__attribute__((__require_constant_initialization__))
static const foo_u x = {0};
does have a constant initializer.
(This was triggered by musl's pthread_mutex_t type when building under C++11.)
Reviewers: rsmith
Subscribers: EricWF, cfe-commits
Differential Revision: https://reviews.llvm.org/D28427
llvm-svn: 291480
In C++11, a destructor's implicit exception-spec is nothrow.
The IR for the destructor's invocation changed from invoke to call.
Differential Revision: https://reviews.llvm.org/D28425
llvm-svn: 291458
Fixes a regression introduced in r291045, which would lead to link
errors. While we should no longer encounter unparsed or uninstantiated
default arguments in this codepath, we still need to call
CheckCXXDefaultArgExpr to mark the default argument expressions as
ODR-used.
llvm-svn: 291453
Use the canonical decl in pointer comparisons with the default
constructor closure decl. Otherwise we don't produce the correct
"@@QAEXXZ" mangling, which essentially means "void(void) thiscall public
instance method".
llvm-svn: 291448
Summary:
This patch makes the type_mismatch static data 7 bytes smaller (and it
ends up being 16 bytes smaller due to alignment restrictions, at least
on some x86-64 environments).
It revs up the type_mismatch handler version since we're breaking binary
compatibility. I will soon post a patch for the compiler-rt side.
Reviewers: rsmith, kcc, vitalybuka, pgousseau, gbedwell
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D28242
llvm-svn: 291236
Summary:
Replace some old code that probably pre-dated the change to delay
emission of dllexported code until after the closing brace of the
outermost record type. Only uninstantiated default argument expressions
need to be handled now. It is enough to instantiate default argument
expressions when instantiating dllexported default ctors. This also
fixes some double-diagnostic issues in this area.
Fixes PR31500
Reviewers: rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D28274
llvm-svn: 291045
Front end component (back end changes are D27392). The vectorcall
calling convention was broken subtly in two cases. First,
it didn't properly handle homogeneous vector aggregates (HVAs).
Second, the vectorcall specification requires that only the
first 6 parameters be eligible for register assignment.
This patch fixes both issues.
Differential Revision: https://reviews.llvm.org/D27529
llvm-svn: 291041
in non-void functions that fall off at the end without returning a value when
compiling C++.
Clang uses the new compiler flag to determine when it should treat control flow
paths that fall off the end of a non-void function as unreachable. If
-fno-strict-return is on, the code generator emits the ureachable and trap
IR only when the function returns either a record type with a non-trivial
destructor or another non-trivially copyable type.
The primary goal of this flag is to avoid treating falling off the end of a
non-void function as undefined behaviour. The burden of undefined behaviour
is placed on the caller instead: if the caller ignores the returned value then
the undefined behaviour is avoided. This kind of behaviour is useful in
several cases, e.g. when compiling C code in C++ mode.
rdar://13102603
Differential Revision: https://reviews.llvm.org/D27163
llvm-svn: 290960
This seems like it must've been a leftover by accident - no tests were
backing it up & it doesn't make much sense to include size/alignment on
class declarations (it'd only be on those declarations for which the
definition was available - otherwise the size/alignment would not be
known).
llvm-svn: 290631
-fno-inline-functions, -O0, and optnone.
These were really, really tangled together:
- We used the noinline LLVM attribute for -fno-inline
- But not for -fno-inline-functions (breaking LTO)
- But we did use it for -finline-hint-functions (yay, LTO is happy!)
- But we didn't for -O0 (LTO is sad yet again...)
- We had weird structuring of CodeGenOpts with both an inlining
enumeration and a boolean. They interacted in weird ways and
needlessly.
- A *lot* of set smashing went on with setting these, and then got worse
when we considered optnone and other inlining-effecting attributes.
- A bunch of inline affecting attributes were managed in a completely
different place from -fno-inline.
- Even with -fno-inline we failed to put the LLVM noinline attribute
onto many generated function definitions because they didn't show up
as AST-level functions.
- If you passed -O0 but -finline-functions we would run the normal
inliner pass in LLVM despite it being in the O0 pipeline, which really
doesn't make much sense.
- Lastly, we used things like '-fno-inline' to manipulate the pass
pipeline which forced the pass pipeline to be much more
parameterizable than it really needs to be. Instead we can *just* use
the optimization level to select a pipeline and control the rest via
attributes.
Sadly, this causes a bunch of churn in tests because we don't run the
optimizer in the tests and check the contents of attribute sets. It
would be awesome if attribute sets were a bit more FileCheck friendly,
but oh well.
I think this is a significant improvement and should remove the semantic
need to change what inliner pass we run in order to comply with the
requested inlining semantics by relying completely on attributes. It
also cleans up tho optnone and related handling a bit.
One unfortunate aspect of this is that for generating alwaysinline
routines like those in OpenMP we end up removing noinline and then
adding alwaysinline. I tried a bunch of other approaches, but because we
recompute function attributes from scratch and don't have a declaration
here I couldn't find anything substantially cleaner than this.
Differential Revision: https://reviews.llvm.org/D28053
llvm-svn: 290398
Much to my surprise, '-disable-llvm-optzns' which I thought was the
magical flag I wanted to get at the raw LLVM IR coming out of Clang
deosn't do that. It still runs some passes over the IR. I don't want
that, I really want the *raw* IR coming out of Clang and I strongly
suspect everyone else using it is in the same camp.
There is actually a flag that does what I want that I didn't know about
called '-disable-llvm-passes'. I suspect many others don't know about it
either. It both does what I want and is much simpler.
This removes the confusing version and makes that spelling of the flag
an alias for '-disable-llvm-passes'. I've also moved everything in Clang
to use the 'passes' spelling as it seems both more accurate (*all* LLVM
passes are disabled, not just optimizations) and much easier to remember
and spell correctly.
This is part of simplifying how Clang drives LLVM to make it cleaner to
wire up to the new pass manager.
Differential Revision: https://reviews.llvm.org/D28047
llvm-svn: 290392
This is a recommit of r290149, which was reverted in r290169 due to msan
failures. msan was failing because we were calling
`isMostDerivedAnUnsizedArray` on an invalid designator, which caused us
to read uninitialized memory. To fix this, the logic of the caller of
said function was simplified, and we now have a `!Invalid` assert in
`isMostDerivedAnUnsizedArray`, so we can catch this particular bug more
easily in the future.
Fingers crossed that this patch sticks this time. :)
Original commit message:
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
llvm-svn: 290297
effect they would have in C++11. In particular, they do not prevent
value-initialization from performing zero-initialization, nor do they prevent a
struct from being an aggregate.
llvm-svn: 290229
In stack-reuse-miscompile.cpp, the allocas for the temps come out in
a different order depending on whether the dialect is C++03 or
C++11. Specify C++03 explicitly to avoid depending on the default.
Differential Revision: http://reviews.llvm.org/D27956
llvm-svn: 290208
If a dtor has no interesting members, then it ends up being nothrow,
which affects the generated IR. Modify some tests to tolerate this
difference between C++03 and C++11.
Differential Revision: http://reviews.llvm.org/D27936
llvm-svn: 290207
In C++11 we don't emit vtables as eagerly as we do for C++03, so
fiddle the tests to emit them when the test expects them.
Differential Revision: http://reviews.llvm.org/D27994
llvm-svn: 290205
This commit fails MSan when running test/CodeGen/object-size.c in
a confusing way. After some discussion with George, it isn't really
clear what is going on here. We can make the MSan failure go away by
testing for the invalid bit, but *why* things are invalid isn't clear.
And yet, other code in the surrounding area is doing precisely this and
testing for invalid.
George is going to take a closer look at this to better understand the
nature of the failure and recommit it, for now backing it out to clean
up MSan builds.
llvm-svn: 290169
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
Differential Revision: https://reviews.llvm.org/D14274
llvm-svn: 290149
Reid Kleckner