Fixes link errors with clang and the latest Visual C++ 14.21.27702
headers, which was reported as PR42027.
I chose to intentionally make these things linkonce_odr, i.e.
discardable, so that we don't emit definitions of these things in every
translation unit that includes STL headers.
Note that this is *not* what MSVC does: MSVC has not yet implemented C++
DR2387, so they emit fully specialized constexpr variable templates with
static / internal linkage.
Reviewers: rsmith
Differential Revision: https://reviews.llvm.org/D63175
llvm-svn: 363191
Seems like a logical extension to me - and of interest because it might
help reduce the debug info size of libc++ by applying this attribute to
type traits that have a disproportionate debug info cost compared to the
benefit (& possibly harm/confusion) they cause users.
llvm-svn: 362856
LLVM IR recently added a Type parameter to the byval Attribute, so that
when pointers become opaque and no longer have an element type the
information will still be present in IR.
For now the Type parameter is optional (which is why Clang didn't need
this change at the time), but it will become mandatory soon.
llvm-svn: 362652
Tests that use -O1, -O2 and -O3 would often produce different results
with the new pass manager which makes these tests fail. Disable new PM
explicitly for these tests.
Differential Revision: https://reviews.llvm.org/D58375
llvm-svn: 362580
unordered initialization and internal linkage.
We'll run their initializers once on each reference, so we need a guard
variable even though they only have a single definition.
llvm-svn: 362562
This is a follow-up to r362293 which fixed exponential time needed
for mangling certain templates. This fixes the same issue if that
template pattern happens in template arguments > 10: The first
ten template arguments can use back references, and r362293 added
caching for back references. For latter arguments, we have to add
a cache for the mangling itself instead.
Fixes PR42091 even more.
Differential Revision: https://reviews.llvm.org/D62780
llvm-svn: 362560
Template back references used to be recursively recomputed, add a
memoization cache to cut down on this.
Since there are now two different types of argument maps, rename the
existing TypeBackReferences to FunArgBackReferences, and rename
mangleArgumentType() to mangleFunctionArgumentType().
Fixes PR42091, the input there now takes 50ms instead of 7s to compile.
No intended behavior change.
Differential Revision: https://reviews.llvm.org/D62746
llvm-svn: 362293
Summary:
Keeps track of the enums that were used by saving them as DIGlobalVariables,
since CodeView emits debug info for global constants.
Reviewers: rnk
Subscribers: aprantl, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62635
llvm-svn: 362166
Since byval is now a typed attribute it gets sorted slightly differently by
LLVM when the order of attributes is being canonicalized. This updates the few
Clang tests that depend on the old order.
Clang patch is unchanged.
llvm-svn: 362129
Summary:
Add static data members to IR debug info's list of global variables
so that they are emitted as S_CONSTANT records.
Related to https://bugs.llvm.org/show_bug.cgi?id=41615.
Reviewers: rnk
Subscribers: aprantl, cfe-commits, llvm-commits, thakis
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D62167
llvm-svn: 362038
Since byval is now a typed attribute it gets sorted slightly differently by
LLVM when the order of attributes is being canonicalized. This updates the few
Clang tests that depend on the old order.
llvm-svn: 362013
Summary:
After https://github.com/emscripten-core/emscripten/pull/8651, Emscripten
supports the full UBSan runtime. This includes the VPtr sanitizer.
This diff allows clang to generate code that uses the VPtr sanitizer for
Emscripten.
Patch by Guanzhong Chen
Reviewers: tlively, aheejin
Reviewed By: aheejin
Subscribers: dschuff, sbc100, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D62559
llvm-svn: 362004
The mangling used to contain the MD5 name of both the RTTI type
descriptor and the name of the copy ctor in MSVC2013, but it changed
to just the former in 2015. It looks like it changed back to the old
mangling in VS2017 version 15.7 and onwards, including VS2019 (version
16.0). VS2017 version 15.0 still has the VS2015 mangling. Versions
between 15.0 and 15.7 are't on godbolt. I found 15.4 (_MSC_VER 1911)
locally and that uses the 15.0 mangling still, but I didn't find 15.5 or
15.6, so I'm not sure where exactly it changed back.
Differential Revision: https://reviews.llvm.org/D62490
llvm-svn: 361959
The source location builtins are implemented as keywords, but
__has_builtin should still report true for them.
This patch also fixes a test failure on systemz where the alignment
of string literals is 2 not 1.
llvm-svn: 361920
This was reverted in r360086 as it was supected of causing mysterious test
failures internally. However, it was never concluded that this patch was the
root cause.
> The code was previously checking that candidates for sinking had exactly
> one use or were a store instruction (which can't have uses). This meant
> we could sink call instructions only if they had a use.
>
> That limitation seemed a bit arbitrary, so this patch changes it to
> "instruction has zero or one use" which seems more natural and removes
> the need to special-case stores.
>
> Differential revision: https://reviews.llvm.org/D59936
llvm-svn: 361811
r355317 changed builtins/allocation functions to use the default calling
convention in order to support platforms that use non-cdecl calling
conventions by default.
However the default calling convention is overridable on Windows 32 bit
implementations with some of the /G options. The intent is to permit the
user to set the calling convention of normal functions, however it
should NOT apply to builtins and C++ allocation functions.
This patch ensures that the builtin/allocation functions always use the
Target specific Calling Convention, ignoring the user overridden version
of said default.
llvm-svn: 361507
Summary:
This patch implements the source location builtins `__builtin_LINE(), `__builtin_FUNCTION()`, `__builtin_FILE()` and `__builtin_COLUMN()`. These builtins are needed to implement [`std::experimental::source_location`](https://rawgit.com/cplusplus/fundamentals-ts/v2/main.html#reflection.src_loc.creation).
With the exception of `__builtin_COLUMN`, GCC also implements these builtins, and Clangs behavior is intended to match as closely as possible.
Reviewers: rsmith, joerg, aaron.ballman, bogner, majnemer, shafik, martong
Reviewed By: rsmith
Subscribers: rnkovacs, loskutov, riccibruno, mgorny, kunitoki, alexr, majnemer, hfinkel, cfe-commits
Differential Revision: https://reviews.llvm.org/D37035
llvm-svn: 360937
This fixes a crash where we would neglect to mark a destructor referenced for an
__attribute__((no_destory)) array. The destructor is needed though, since if an
exception is thrown we need to cleanup the elements.
rdar://48462498
Differential revision: https://reviews.llvm.org/D61165
llvm-svn: 360446
Darwin if the version of libc++abi isn't new enough to include the fix
in r319123
This patch resurrects r264998, which was committed to work around a bug
in libc++abi that was causing _cxa_allocate_exception to return a memory
that wasn't double-word aligned.
http://lists.llvm.org/pipermail/cfe-commits/Week-of-Mon-20160328/154332.html
In addition, this patch makes clang issue a warning if the type of the
thrown object requires an alignment that is larger than the minimum
guaranteed by the target C++ runtime.
rdar://problem/49864414
Differential Revision: https://reviews.llvm.org/D61667
llvm-svn: 360404
This reverts r357452 (git commit 21eb771dcb).
This was causing strange optimization-related test failures on an internal test. Will followup with more details offline.
llvm-svn: 360086
new expression.
This was voted into C++20 as a defect report resolution, so we
retroactively apply it to all prior language modes (though it can never
actually be used before C++11 mode).
llvm-svn: 360006
Summary:
Fixes PR41677
Consider:
template <typename LHS, typename RHS> constexpr bool is_same_v = false;
template <typename T> constexpr bool is_same_v<T, T> = true;
template constexpr bool is_same_v<int, int>;
Before this change, when emitting debug info for the
`is_same_v<int, int>` global variable, clang would crash because it
would try to use the template parameter list from the partial
specialization to give parameter names to template arguments. This
doesn't work in general, since a partial specialization can have fewer
arguments than the primary template. Therefore, always use the primary
template. Hypothetically we could try to use the parameter names from
the partial specialization when possible, but it's not clear this really
helps debugging in practice.
Reviewers: JDevlieghere, aprantl, ormris, dblaikie
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D61408
llvm-svn: 359809
This makes sure that code built with headers for a statically linked
libc++ also works when linking to the DLL version, when the DLL
hasn't been built with --export-all-symbols.
This matches what GCC for MinGW does for this test case.
Differential Revision: https://reviews.llvm.org/D61177
llvm-svn: 359345
Normally, in MinGW mode, inline methods aren't dllexported.
However, in the case of a dllimported template instantiation,
the inline methods aren't instantiated locally, but referenced
from the instantiation. Therefore, those methods also need to
be dllexported, in the case of an instantiation.
GCC suffers from the same issue, reported at [1], but the issue
is still unresolved there.
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89088
Differential Revision: https://reviews.llvm.org/D61176
llvm-svn: 359343
An explicit template instantiation declaration used to let
callers assume both outer and nested classes instantiations were
defined in a different translation unit.
If the instantiation is marked dllexport, only the outer class
is exported, but the caller will try to reference the instantiation
of both outer and inner classes.
This makes MinGW mode match both MSVC and Windows Itanium, by
having instantations only cover the outer class, and locally emitting
definitions of the nested classes. Windows Itanium was changed to
use this behavious in SVN r300804.
This deviates from what GCC does, but should be safe (and only
inflate the object file size a bit, but MSVC and Windows Itanium
modes do the same), and fixes cases where inner classes aren't
dllexported.
This fixes missing references in combination with dllexported/imported
template intantiations.
GCC suffers from the same issue, reported at [1], but the issue
is still unresolved there. The issue can probably be solved either
by making dllexport cover all nested classes as well, or this
way (matching MSVC).
[1] https://gcc.gnu.org/bugzilla/show_bug.cgi?id=89087
Differential Revision: https://reviews.llvm.org/D61175
llvm-svn: 359342
Contrary to MSVC, GCC/MinGW needs to have the dllexport attribute
on the template instantiation declaration, not on the definition.
Previously clang never marked explicit template instantiations as
dllexport in MinGW mode, if the instantiation had a previous
declaration, regardless of where the attribute was placed. This
makes Clang behave like GCC in this regard, and allows using the
same attribute form for both MinGW compilers.
This fixes PR40256.
Differential Revision: https://reviews.llvm.org/D61118
llvm-svn: 359285
const-qualified type is not implicitly given internal linkage. But a
variable template declared 'static' is.
This reinstates part of r359048, reverted in r359076.
llvm-svn: 359260
This reverts r359250 (git commit 4730604bd3)
The newly added test should use -cc1 and -emit-llvm and there are other
test failures that need fixing.
llvm-svn: 359251
Statically link certain runtime library functions for MSVC/GNU Windows
environments. This is consistent with MSVC behavior.
Fixes LNK4286 and LNK4217 warnings from link.exe when linking the static
CRT:
LINK : warning LNK4286: symbol '__std_terminate' defined in 'libvcruntime.lib(ehhelpers.obj)' is imported by 'ASAN_NOINST_TEST_OBJECTS.asan_noinst_test.cc.x86_64-calls.o'
LINK : warning LNK4286: symbol '__std_terminate' defined in 'libvcruntime.lib(ehhelpers.obj)' is imported by 'ASAN_NOINST_TEST_OBJECTS.asan_test_main.cc.x86_64-calls.o'
LINK : warning LNK4217: symbol '_CxxThrowException' defined in 'libvcruntime.lib(throw.obj)' is imported by 'ASAN_NOINST_TEST_OBJECTS.gtest-all.cc.x86_64-calls.o' in function '"int `public: static class UnitTest::GetInstance * __cdecl testing::UnitTest::GetInstance(void)'::`1'::dtor$5" (?dtor$5@?0??GetInstance@UnitTest@testing@@SAPEAV12@XZ@4HA)'
Reviewers: mstorsjo, efriedma, TomTan, compnerd, smeenai, mgrang
Subscribers: abdulras, theraven, smeenai, pcc, mehdi_amini, javed.absar, inglorion, kristof.beyls, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D55229
llvm-svn: 359250
(this would regress size without a corresponding LLVM change that avoids
putting other user defined types inside type units when they aren't in
their own type units - instead emitting declarations inside the type
unit and a definition in the primary CU)
Reviewers: aprantl
Differential Revision: https://reviews.llvm.org/D61079
llvm-svn: 359235
Summary:
Add a new variant to GlobalDecl for these so that we can detect them
more easily during debug info emission and handle them appropriately.
Reviewers: rsmith, rjmccall, jyu2
Subscribers: aprantl, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D60930
llvm-svn: 359148
The change breaks libc++ with the follwing error:
In file included from valarray:4:
.../include/c++/v1/valarray:1062:60: error: explicit instantiation declaration of 'valarray<_Tp>' with internal linkage
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS valarray<size_t>::valarray(size_t))
^
.../include/c++/v1/valarray:1063:60: error: explicit instantiation declaration of '~valarray<_Tp>' with internal linkage
_LIBCPP_EXTERN_TEMPLATE(_LIBCPP_FUNC_VIS valarray<size_t>::~valarray())
llvm-svn: 359076
Summary:
This patch implements `__builtin_is_constant_evaluated` as specifier by [P0595R2](https://wg21.link/p0595r2). It is built on the back of Bill Wendling's work for `__builtin_constant_p()`.
More tests to come, but early feedback is appreciated.
I plan to implement warnings for common mis-usages like those belowe in a following patch:
```
void foo(int x) {
if constexpr (std::is_constant_evaluated())) { // condition is always `true`. Should use plain `if` instead.
foo_constexpr(x);
} else {
foo_runtime(x);
}
}
```
Reviewers: rsmith, MaskRay, bruno, void
Reviewed By: rsmith
Subscribers: dexonsmith, zoecarver, fdeazeve, kristina, cfe-commits
Differential Revision: https://reviews.llvm.org/D55500
llvm-svn: 359067
The original commit caused false positives from AddressSanitizer's
use-after-scope checks, which have now been fixed in r358478.
> The code was previously checking that candidates for sinking had exactly
> one use or were a store instruction (which can't have uses). This meant
> we could sink call instructions only if they had a use.
>
> That limitation seemed a bit arbitrary, so this patch changes it to
> "instruction has zero or one use" which seems more natural and removes
> the need to special-case stores.
>
> Differential revision: https://reviews.llvm.org/D59936
llvm-svn: 358483
Summary:
alloca isn’t auto-init’d right now because it’s a different path in clang that
all the other stuff we support (it’s a builtin, not an expression).
Interestingly, alloca doesn’t have a type (as opposed to even VLA) so we can
really only initialize it with memset.
<rdar://problem/49794007>
Subscribers: jkorous, dexonsmith, cfe-commits, rjmccall, glider, kees, kcc, pcc
Tags: #clang
Differential Revision: https://reviews.llvm.org/D60548
llvm-svn: 358243
Summary:
These flags are used when emitting debug info and needed to initialize subprogram and member function attributes (function options) for Codeview. These function options are used to create an accurate compiler type for UDT symbols (class/struct/union) from PDBs.
The Trivial flag was introduced in https://reviews.llvm.org/D45122
It's been pointed out that Trivial and NonTrivial may imply each other and that seems to be the case in the current tests. This change combines them into a single flag -- NonTrivial -- and updates the corresponding unit tests. There is an additional change to llvm to update the flags.
Reviewers: rnk, zturner, dblaikie, probinson, Hui
Reviewed By: dblaikie
Subscribers: aprantl, jdoerfert, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D59347
llvm-svn: 358219
Improved classification of address space cast when qualification
conversion is performed - prevent adding addr space cast for
non-pointer and non-reference types. Take address space correctly
from the pointee.
Also pass correct address space from 'this' object using
AggValueSlot when generating addrspacecast in the constructor
call.
Differential Revision: https://reviews.llvm.org/D59988
llvm-svn: 357682
This revision causes tests to fail under ASAN. Since the cause of the failures
is not clear (could be ASAN, could be a Clang bug, could be a bug in this
revision), the safest course of action seems to be to revert while investigating.
llvm-svn: 357667
The code was previously checking that candidates for sinking had exactly
one use or were a store instruction (which can't have uses). This meant
we could sink call instructions only if they had a use.
That limitation seemed a bit arbitrary, so this patch changes it to
"instruction has zero or one use" which seems more natural and removes
the need to special-case stores.
Differential revision: https://reviews.llvm.org/D59936
llvm-svn: 357452
Before this patch, CGLoop would dump all transformations for a loop into
a single LoopID without encoding any order in which to apply them.
rL348944 added the possibility to encode a transformation order using
followup-attributes.
When a loop has more than one transformation, use the follow-up
attribute define the order in which they are applied. The emitted order
is the defacto order as defined by the current LLVM pass pipeline,
which is:
LoopFullUnrollPass
LoopDistributePass
LoopVectorizePass
LoopUnrollAndJamPass
LoopUnrollPass
MachinePipeliner
This patch should therefore not change the assembly output, assuming
that all explicit transformations can be applied, and no implicit
transformations in-between. In the former case,
WarnMissedTransformationsPass should emit a warning (except for
MachinePipeliner which is not implemented yet). The latter could be
avoided by adding 'llvm.loop.disable_nonforced' attributes.
Because LoopUnrollAndJamPass processes a loop nest, generation of the
MDNode is delayed to after the inner loop metadata have been processed.
A temporary LoopID is therefore used to annotate instructions and
RAUW'ed by the actual LoopID later.
Differential Revision: https://reviews.llvm.org/D57978
llvm-svn: 357415
Just as as llvm IR supports explicitly specifying numeric value ids
for instructions, and emits them by default in textual output, now do
the same for blocks.
This is a slightly incompatible change in the textual IR format.
Previously, llvm would parse numeric labels as string names. E.g.
define void @f() {
br label %"55"
55:
ret void
}
defined a label *named* "55", even without needing to be quoted, while
the reference required quoting. Now, if you intend a block label which
looks like a value number to be a name, you must quote it in the
definition too (e.g. `"55":`).
Previously, llvm would print nameless blocks only as a comment, and
would omit it if there was no predecessor. This could cause confusion
for readers of the IR, just as unnamed instructions did prior to the
addition of "%5 = " syntax, back in 2008 (PR2480).
Now, it will always print a label for an unnamed block, with the
exception of the entry block. (IMO it may be better to print it for
the entry-block as well. However, that requires updating many more
tests.)
Thus, the following is supported, and is the canonical printing:
define i32 @f(i32, i32) {
%3 = add i32 %0, %1
br label %4
4:
ret i32 %3
}
New test cases covering this behavior are added, and other tests
updated as required.
Differential Revision: https://reviews.llvm.org/D58548
llvm-svn: 356789
This diff previously exposed a bug in LLVM's IRLinker, breaking
buildbots that tried to self-host LLVM with monolithic LTO.
The bug is now in LLVM by D59552
Original commit message:
As PR17480 describes, clang does not support the used attribute
for member functions of class templates. This means that if the member
function is not used, its definition is never instantiated. This patch
changes clang to emit the definition if it has the used attribute.
Test Plan: Added a testcase
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D56928
llvm-svn: 356598
The attribute pass_dynamic_object_size(n) behaves exactly like
pass_object_size(n), but instead of evaluating __builtin_object_size on calls,
it evaluates __builtin_dynamic_object_size, which has the potential to produce
runtime code when the object size can't be determined statically.
Differential revision: https://reviews.llvm.org/D58757
llvm-svn: 356515
As background, when constructing a complete object, virtual bases are
constructed first. If an exception is thrown later in the ctor, those
virtual bases are destroyed, so sema marks the relevant constructors and
destructors of virtual bases as referenced. If necessary, they are
emitted.
However, an abstract class can never be used to construct a complete
object. In the Itanium C++ ABI, this works out nicely, because we never
end up emitting the "complete" constructor variant, only the "base"
constructor variant, which can be called by constructors of derived
classes. Clang's Sema::MarkBaseAndMemberDestructorsReferenced is aware
of this optimization, and it does not mark ctors and dtors of virtual
bases referenced when the constructor of an abstract class is emitted.
In the Microsoft ABI, there are no complete/base variants, so before
this change, the constructor of an abstract class could reference ctors
and dtors of a virtual base without marking them referenced. This could
lead to unresolved symbol errors at link time, as reported in PR41065.
The fix is to implement the same optimization as Sema: If the class is
abstract, don't bother initializing its virtual bases. The "is this
class the most derived class" check in the constructor will never pass,
and the virtual base constructor calls are always dead. Skip them.
I think Richard noticed this missed optimization back in 2016 when he
was implementing inheriting constructors. I wasn't able to find any bugs
or email about it, though.
Fixes PR41065
llvm-svn: 356425
Summary:
Because in wasm we merge all catch clauses into one big catchpad, in
case none of the types in catch handlers matches after we test against
each of them, we should unwind to the next EH enclosing scope. For this,
we should NOT use a call to `__cxa_rethrow` but rather a call to our own
rethrow intrinsic, because what we're trying to do here is just to
transfer the control flow into the next enclosing EH pad (or the
caller). Calls to `__cxa_rethrow` should only be used after a call to
`__cxa_begin_catch`.
Reviewers: dschuff
Subscribers: sbc100, jgravelle-google, sunfish, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D59353
llvm-svn: 356317
Summary:
This patch fixes several small problems with external layouts support in
`MicrosoftRecordLayoutBuilder`:
- aligns properly the size of a struct that ends with a bit field. It was
aligned on byte before, not on the size of the field, so the struct size was
smaller than it should be;
- adjusts the struct size when injecting a vbptr in the case when there were no
bases or fields allocated after the vbptr. Similarly, without the adjustment
the struct was smaller than it should be;
- the same fix as above for the vfptr.
All these fixes affect the non-virtual size of a struct, so they are tested
through non-virtual inheritance.
Reviewers: rnk, zturner, rsmith
Reviewed By: rnk
Subscribers: jdoerfert, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D58544
llvm-svn: 356047
Summary:
This is a test case to go with D44406 which added FlagNonTrivial to mark that a C++ record is non-trivial to support CodeView debug emission.
While it looks like FlagTypePassByValue can imply triviality and FlagTypePassByReference can imply non-triviality that is not true. Some non-trivial cases use a combination of FlagNonTrivial and FlagTypePassByValue instead of FlagTypePassByReference. See the test cases and D44406 for discussion.
Reviewers: dblaikie, rnk, zturner
Reviewed By: dblaikie
Subscribers: jdoerfert, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D59010
llvm-svn: 355890
There is nontrivial bug caused in lld that I need to further
investigate. Meanwhile, I'll revert this.
This reverts commit 8297e93480c636dc90fd14653c5a66406193363f.
llvm-svn: 355721
The patch originally broke code that was incompatible with GCC, but
we want to follow GCC behavior here according to the discussion in
https://reviews.llvm.org/D58216
Original commit message:
As PR17480 describes, clang does not support the used attribute
for member functions of class templates. This means that if the member
function is not used, its definition is never instantiated. This patch
changes clang to emit the definition if it has the used attribute.
Test Plan: Added a testcase
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D56928
llvm-svn: 355627
On SPIR targets, the default calling convention is SpirFunction.
However, operator new/delete and builtins were being created with CC_C.
The result is indirect references to new/delete (or builtins that are permitted
to be called indirectly have a mismatched type, as well as questionable codegen
in some cases.
This patch sets both to the default calling convention, so that it
properly matches the calling convention of the target.
Differential Revision: https://reviews.llvm.org/D58844
Change-Id: I52065bb00bc2655945caea8f29c409ba1e0ac24a
llvm-svn: 355317
When emitting initializers for local structures for code built with
-ftrivial-auto-var-init, replace constant structures with sequences of
stores.
This appears to greatly help removing dead initialization stores to those
locals that are later overwritten by other data.
This also removes a lot of .rodata constants (see PR40605), replacing most
of them with immediate values (for Linux kernel the .rodata size is
reduced by ~1.9%)
llvm-svn: 355181
When generating initializers for local structures in the
-ftrivial-auto-var-init mode, explicitly wipe the padding bytes with
either 0x00 or 0xAA.
This will allow us to automatically handle the padding when splitting
the initialization stores (see https://reviews.llvm.org/D57898).
Reviewed at https://reviews.llvm.org/D58188
llvm-svn: 354861
Summary:
- If a string literal is reused directly, need to add necessary address
space casting if the target requires that.
Reviewers: yaxunl
Subscribers: jvesely, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D58509
llvm-svn: 354610
Summary:
Blocks that capture themselves (and escape) after initialization currently codegen wrong because this:
bool capturedByInit =
Init && emission.IsEscapingByRef && isCapturedBy(D, Init);
Address Loc =
capturedByInit ? emission.Addr : emission.getObjectAddress(*this);
Already adjusts Loc from thr alloca to a GEP. This code:
if (emission.IsEscapingByRef)
Loc = emitBlockByrefAddress(Loc, &D, /*follow=*/false);
Was trying to do the same adjustment, and a GEP on a GEP (returning an int) triggers an assertion.
<rdar://problem/47943027>
Reviewers: ahatanak
Subscribers: jkorous, dexonsmith, cfe-commits, rjmccall
Tags: #clang
Differential Revision: https://reviews.llvm.org/D58218
llvm-svn: 354147
expression is a discarded-value expression.
Summary:
We used to get this wrong in three ways:
1) During parsing, an expression-statement followed by the }) ending a
statement expression was always treated as producing the value of the
statement expression. That's wrong for ({ if (1) expr; })
2) During template instantiation, various kinds of statement (most
statements not appearing directly in a compound-statement) were not
treated as discarded-value expressions, resulting in missing volatile
loads (etc).
3) In all contexts, an expression-statement with attributes was not
treated as producing the value of the statement expression, eg
({ [[attr]] expr; }).
Also fix incorrect enforcement of OpenMP rule that directives can "only
be placed in the program at a position where ignoring or deleting the
directive would result in a program with correct syntax". In particular,
a label (be it goto, case, or default) should not affect whether
directives are permitted.
Reviewers: aaron.ballman, rjmccall
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D57984
llvm-svn: 354090
Found by `git grep '\/\/ CHECK-[^: ]* ' clang/test/ | grep -v RUN:`.
Also tweak CodeGenCXX/arm-swiftcall.cpp to still pass now that it checks more.
Differential Revision: https://reviews.llvm.org/D58061
llvm-svn: 353744
Some of these functions take some extraneous arguments, e.g. EltSize,
Offset, which are computable from the Type and DataLayout.
Add some asserts to ensure that the computed values are consistent
with the passed-in values, in preparation for eliminating the
extraneous arguments. This also asserts that the Type is an Array for
the calls named "Array" and a Struct for the calls named "Struct".
Then, correct a couple of errors:
1. Using CreateStructGEP on an array type. (this causes the majority
of the test differences, as struct GEPs are created with i32
indices, while array GEPs are created with i64 indices)
2. Passing the wrong Offset to CreateStructGEP in TargetInfo.cpp on
x86-64 NACL (which uses 32-bit pointers).
Differential Revision: https://reviews.llvm.org/D57766
llvm-svn: 353529
Summary:
Automatic initialization [1] of __block variables was trampling over the block's
headers after they'd been initialized, which caused self-init usage to crash,
such as here:
typedef struct XYZ { void (^block)(); } *xyz_t;
__attribute__((noinline))
xyz_t create(void (^block)()) {
xyz_t myself = malloc(sizeof(struct XYZ));
myself->block = block;
return myself;
}
int main() {
__block xyz_t captured = create(^(){ (void)captured; });
}
This type of code shouldn't be broken by variable auto-init, even if it's
sketchy.
[1] With -ftrivial-auto-var-init=pattern
<rdar://problem/47798396>
Reviewers: rjmccall, pcc, kcc
Subscribers: jkorous, dexonsmith, cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D57797
llvm-svn: 353495
The assert added to EmitCall there was triggering in Windows Chromium
builds, due to a mismatch of the return type.
The MSVC constructor call extension (`this->Foo::Foo()`) was emitting
the constructor call from 'EmitCXXMemberOrOperatorMemberCallExpr' via
calling 'EmitCXXMemberOrOperatorCall', instead of
'EmitCXXConstructorCall'. On targets where HasThisReturn is true, that
was failing to set the proper return type in the call info.
Switching to calling EmitCXXConstructorCall also allowed removing some
code e.g. the trivial copy/move support, which is already handled in
EmitCXXConstructorCall.
Ref: https://bugs.chromium.org/p/chromium/issues/detail?id=928861
Differential Revision: https://reviews.llvm.org/D57794
llvm-svn: 353246
When Clang/LLVM is built with the CLANG_DEFAULT_STD_CXX CMake macro that sets
the default standard to something other than C++14, there are a number of lit
tests that fail as they rely on the C++14 default.
This patch just adds the language standard option explicitly to such test cases.
Differential revision: https://reviews.llvm.org/D57581
llvm-svn: 353163
Summary:
UBSan wants to detect when unreachable code is actually reached, so it
adds instrumentation before every unreachable instruction. However, the
optimizer will remove code after calls to functions marked with
noreturn. To avoid this UBSan removes noreturn from both the call
instruction as well as from the function itself. Unfortunately, ASan
relies on this annotation to unpoison the stack by inserting calls to
_asan_handle_no_return before noreturn functions. This is important for
functions that do not return but access the the stack memory, e.g.,
unwinder functions *like* longjmp (longjmp itself is actually
"double-proofed" via its interceptor). The result is that when ASan and
UBSan are combined, the noreturn attributes are missing and ASan cannot
unpoison the stack, so it has false positives when stack unwinding is
used.
Changes:
Clang-CodeGen now directly insert calls to `__asan_handle_no_return`
when a call to a noreturn function is encountered and both
UBsan-unreachable and ASan are enabled. This allows UBSan to continue
removing the noreturn attribute from functions without any changes to
the ASan pass.
Previously generated code:
```
call void @longjmp
call void @__asan_handle_no_return
call void @__ubsan_handle_builtin_unreachable
```
Generated code (for now):
```
call void @__asan_handle_no_return
call void @longjmp
call void @__asan_handle_no_return
call void @__ubsan_handle_builtin_unreachable
```
rdar://problem/40723397
Reviewers: delcypher, eugenis, vsk
Differential Revision: https://reviews.llvm.org/D57278
> llvm-svn: 352690
llvm-svn: 352829
Summary:
As PR17480 describes, clang does not support the used attribute
for member functions of class templates. This means that if the member
function is not used, its definition is never instantiated. This patch
changes clang to emit the definition if it has the used attribute.
Test Plan: Added a testcase
Reviewed By: aaron.ballman
Differential Revision: https://reviews.llvm.org/D56928
llvm-svn: 352740
Summary:
UBSan wants to detect when unreachable code is actually reached, so it
adds instrumentation before every unreachable instruction. However, the
optimizer will remove code after calls to functions marked with
noreturn. To avoid this UBSan removes noreturn from both the call
instruction as well as from the function itself. Unfortunately, ASan
relies on this annotation to unpoison the stack by inserting calls to
_asan_handle_no_return before noreturn functions. This is important for
functions that do not return but access the the stack memory, e.g.,
unwinder functions *like* longjmp (longjmp itself is actually
"double-proofed" via its interceptor). The result is that when ASan and
UBSan are combined, the noreturn attributes are missing and ASan cannot
unpoison the stack, so it has false positives when stack unwinding is
used.
Changes:
Clang-CodeGen now directly insert calls to `__asan_handle_no_return`
when a call to a noreturn function is encountered and both
UBsan-unreachable and ASan are enabled. This allows UBSan to continue
removing the noreturn attribute from functions without any changes to
the ASan pass.
Previously generated code:
```
call void @longjmp
call void @__asan_handle_no_return
call void @__ubsan_handle_builtin_unreachable
```
Generated code (for now):
```
call void @__asan_handle_no_return
call void @longjmp
call void @__asan_handle_no_return
call void @__ubsan_handle_builtin_unreachable
```
rdar://problem/40723397
Reviewers: delcypher, eugenis, vsk
Differential Revision: https://reviews.llvm.org/D57278
llvm-svn: 352690
As Discussed here:
http://lists.llvm.org/pipermail/llvm-dev/2019-January/129543.html
There are problems exposing the _Float16 type on architectures that
haven't defined the ABI/ISel for the type yet, so we're temporarily
disabling the type and making it opt-in.
Differential Revision: https://reviews.llvm.org/D57188
Change-Id: I5db7366dedf1deb9485adb8948b1deb7e612a736
llvm-svn: 352221
Summary:
UBSan wants to detect when unreachable code is actually reached, so it
adds instrumentation before every `unreachable` instruction. However,
the optimizer will remove code after calls to functions marked with
`noreturn`. To avoid this UBSan removes `noreturn` from both the call
instruction as well as from the function itself. Unfortunately, ASan
relies on this annotation to unpoison the stack by inserting calls to
`_asan_handle_no_return` before `noreturn` functions. This is important
for functions that do not return but access the the stack memory, e.g.,
unwinder functions *like* `longjmp` (`longjmp` itself is actually
"double-proofed" via its interceptor). The result is that when ASan and
UBSan are combined, the `noreturn` attributes are missing and ASan
cannot unpoison the stack, so it has false positives when stack
unwinding is used.
Changes:
# UBSan now adds the `expect_noreturn` attribute whenever it removes
the `noreturn` attribute from a function
# ASan additionally checks for the presence of this attribute
Generated code:
```
call void @__asan_handle_no_return // Additionally inserted to avoid false positives
call void @longjmp
call void @__asan_handle_no_return
call void @__ubsan_handle_builtin_unreachable
unreachable
```
The second call to `__asan_handle_no_return` is redundant. This will be
cleaned up in a follow-up patch.
rdar://problem/40723397
Reviewers: delcypher, eugenis
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D56624
llvm-svn: 352003
We can't use any other string, anyway, because its type wouldn't
match the type of the PredefinedExpr.
With this change, we don't compute a "nice" name for the __func__ global
when it's used in the initializer for a constant. This doesn't seem like
a great loss, and I'm not sure how to fix it without either storing more
information in the AST, or somehow threading through the information
from ExprConstant.cpp.
This could break some situations involving BlockDecl; currently,
CodeGenFunction::EmitPredefinedLValue has some logic to intentionally
emit a string different from what Sema computed. This code skips that
logic... but that logic can't work correctly in general anyway. (For
example, sizeof(__func__) returns the wrong result.) Hopefully this
doesn't affect practical code.
Fixes https://bugs.llvm.org/show_bug.cgi?id=40313 .
Differential Revision: https://reviews.llvm.org/D56821
llvm-svn: 351766
With commit r351627, LLVM gained the ability to apply (existing) IPO
optimizations on indirections through callbacks, or transitive calls.
The general idea is that we use an abstraction to hide the middle man
and represent the callback call in the context of the initial caller.
It is described in more detail in the commit message of the LLVM patch
r351627, the llvm::AbstractCallSite class description, and the
language reference section on callback-metadata.
This commit enables clang to emit !callback metadata that is
understood by LLVM. It does so in three different cases:
1) For known broker functions declarations that are directly
generated, e.g., __kmpc_fork_call for the OpenMP pragma parallel.
2) For known broker functions that are identified by their name and
source location through the builtin detection, e.g.,
pthread_create from the POSIX thread API.
3) For user annotated functions that carry the "callback(callee, ...)"
attribute. The attribute has to include the name, or index, of
the callback callee and how the passed arguments can be
identified (as many as the callback callee has). See the callback
attribute documentation for detailed information.
Differential Revision: https://reviews.llvm.org/D55483
llvm-svn: 351629
Summary:
This attribute will allow users to opt specific functions out of
speculative load hardening. This compliments the Clang attribute
named speculative_load_hardening. When this attribute or the attribute
speculative_load_hardening is used in combination with the flags
-mno-speculative-load-hardening or -mspeculative-load-hardening,
the function level attribute will override the default during LLVM IR
generation. For example, in the case, where the flag opposes the
function attribute, the function attribute will take precendence.
The sticky inlining behavior of the speculative_load_hardening attribute
may cause a function with the no_speculative_load_hardening attribute
to be tagged with the speculative_load_hardening tag in
subsequent compiler phases which is desired behavior since the
speculative_load_hardening LLVM attribute is designed to be maximally
conservative.
If both attributes are specified for a function, then an error will be
thrown.
Reviewers: chandlerc, echristo, kristof.beyls, aaron.ballman
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D54909
llvm-svn: 351565
Lambda captures should be destroyed if an exception is thrown only if
the construction of the complete lambda-expression has not completed.
(If the lambda-expression has been fully constructed, any exception will
invoke its destructor, which will destroy the captures.)
This is directly modeled after how we handle the equivalent situation in
InitListExprs.
Note that EmitLambdaLValue was unreachable because in C++11 onwards the
frontend never creates the awkward situation where a prvalue expression
(such as a lambda) is used in an lvalue context (such as the left-hand
side of a class member access).
llvm-svn: 351487
Summary:
Teach clang to mark thread wrappers for thread_local variables with
hidden visibility when the original variable is marked with hidden
visibility. This is necessary on Darwin which exposes the thread wrapper
instead of the thread variable. The thread wrapper would previously
always be created with default visibility unless it had
linkonce*/weak_odr linkage.
Reviewers: rjmccall
Reviewed By: rjmccall
Differential Revision: https://reviews.llvm.org/D56818
llvm-svn: 351457
Summary:
Adds a new -f[no]split-lto-unit flag that is disabled by default to
control module splitting during ThinLTO. It is automatically enabled
for -fsanitize=cfi and -fwhole-program-vtables.
The new EnableSplitLTOUnit codegen flag is passed down to llvm
via a new module flag of the same name.
Depends on D53890.
Reviewers: pcc
Subscribers: ormris, mehdi_amini, inglorion, eraman, steven_wu, dexonsmith, cfe-commits, llvm-commits
Differential Revision: https://reviews.llvm.org/D53891
llvm-svn: 350949
to it is a trivial_abi class.
A class that has all of its copy and move constructors deleted can still
be passed or returned in registers if the class is annotated with
trivial_abi.
This fixes PR39683.
llvm-svn: 350920
This patch adds #pragma clang loop pipeline and #pragma clang loop pipeline_initiation_interval for debugging or reducing compile time purposes. It is possible to disable SWP for concrete loops to save compilation time or to find bugs by not doing SWP to certain loops. It is possible to set value of initiation interval to concrete number to save compilation time by not doing extra pipeliner passes or to check created schedule for specific initiation interval.
Patch by Alexey Lapshin.
llvm-svn: 350414
Summary:
This moves it up from IgnoreParenImpCasts to IgnoreParens, so that more
helpers ignore it. For most clients, this ensures that these helpers
behave the same with and without C++17 enabled, which is what appears to
introduce these new expression nodes.
Fixes PR39881
Reviewers: void, rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D55853
llvm-svn: 350068
GCC does not mangle it when it is not explicit in the source. The
mangler as currently written cannot differentiate between explicit and
implicit calling conventions, so we can't match GCC. Explicit thiscall
conventions are rare, so mangle as if the convention was implicit to be
as ABI compatible as possible.
Also fixes some tests using %itanium_abi_triple in some configurations
as a side effect.
Fixes PR40107.
llvm-svn: 349872
Fixes assertion
> Assertion failed: (isa<X>(Val) && "cast<Ty>() argument of incompatible type!"), function cast, file llvm/Support/Casting.h, line 255.
It was triggered by trying to cast `FunctionDecl` to `CXXMethodDecl` as
`CGF.CurCodeDecl` in `CallBaseDtor::Emit`. It was happening because
cleanups were emitted in `ScalarExprEmitter::VisitExprWithCleanups`
after destroying `InlinedInheritingConstructorScope`, so
`CodeGenFunction.CurCodeDecl` didn't correspond to expected cleanup decl.
Fix the assertion by emitting cleanups before leaving
`InlinedInheritingConstructorScope` and changing `CurCodeDecl`.
Test cases based on a patch by Shoaib Meenai.
Fixes PR36748.
rdar://problem/45805151
Reviewers: rsmith, rjmccall
Reviewed By: rjmccall
Subscribers: jkorous, dexonsmith, cfe-commits, smeenai, compnerd
Differential Revision: https://reviews.llvm.org/D55543
llvm-svn: 349848
Instead of generating llvm.mem.parallel_loop_access metadata, generate
llvm.access.group on instructions and llvm.loop.parallel_accesses on
loops. There is one access group per generated loop.
This is clang part of D52116/r349725.
Differential Revision: https://reviews.llvm.org/D52117
llvm-svn: 349823
Summary:
Add an option to initialize automatic variables with either a pattern or with
zeroes. The default is still that automatic variables are uninitialized. Also
add attributes to request uninitialized on a per-variable basis, mainly to disable
initialization of large stack arrays when deemed too expensive.
This isn't meant to change the semantics of C and C++. Rather, it's meant to be
a last-resort when programmers inadvertently have some undefined behavior in
their code. This patch aims to make undefined behavior hurt less, which
security-minded people will be very happy about. Notably, this means that
there's no inadvertent information leak when:
- The compiler re-uses stack slots, and a value is used uninitialized.
- The compiler re-uses a register, and a value is used uninitialized.
- Stack structs / arrays / unions with padding are copied.
This patch only addresses stack and register information leaks. There's many
more infoleaks that we could address, and much more undefined behavior that
could be tamed. Let's keep this patch focused, and I'm happy to address related
issues elsewhere.
To keep the patch simple, only some `undef` is removed for now, see
`replaceUndef`. The padding-related infoleaks are therefore not all gone yet.
This will be addressed in a follow-up, mainly because addressing padding-related
leaks should be a stand-alone option which is implied by variable
initialization.
There are three options when it comes to automatic variable initialization:
0. Uninitialized
This is C and C++'s default. It's not changing. Depending on code
generation, a programmer who runs into undefined behavior by using an
uninialized automatic variable may observe any previous value (including
program secrets), or any value which the compiler saw fit to materialize on
the stack or in a register (this could be to synthesize an immediate, to
refer to code or data locations, to generate cookies, etc).
1. Pattern initialization
This is the recommended initialization approach. Pattern initialization's
goal is to initialize automatic variables with values which will likely
transform logic bugs into crashes down the line, are easily recognizable in
a crash dump, without being values which programmers can rely on for useful
program semantics. At the same time, pattern initialization tries to
generate code which will optimize well. You'll find the following details in
`patternFor`:
- Integers are initialized with repeated 0xAA bytes (infinite scream).
- Vectors of integers are also initialized with infinite scream.
- Pointers are initialized with infinite scream on 64-bit platforms because
it's an unmappable pointer value on architectures I'm aware of. Pointers
are initialize to 0x000000AA (small scream) on 32-bit platforms because
32-bit platforms don't consistently offer unmappable pages. When they do
it's usually the zero page. As people try this out, I expect that we'll
want to allow different platforms to customize this, let's do so later.
- Vectors of pointers are initialized the same way pointers are.
- Floating point values and vectors are initialized with a negative quiet
NaN with repeated 0xFF payload (e.g. 0xffffffff and 0xffffffffffffffff).
NaNs are nice (here, anways) because they propagate on arithmetic, making
it more likely that entire computations become NaN when a single
uninitialized value sneaks in.
- Arrays are initialized to their homogeneous elements' initialization
value, repeated. Stack-based Variable-Length Arrays (VLAs) are
runtime-initialized to the allocated size (no effort is made for negative
size, but zero-sized VLAs are untouched even if technically undefined).
- Structs are initialized to their heterogeneous element's initialization
values. Zero-size structs are initialized as 0xAA since they're allocated
a single byte.
- Unions are initialized using the initialization for the largest member of
the union.
Expect the values used for pattern initialization to change over time, as we
refine heuristics (both for performance and security). The goal is truly to
avoid injecting semantics into undefined behavior, and we should be
comfortable changing these values when there's a worthwhile point in doing
so.
Why so much infinite scream? Repeated byte patterns tend to be easy to
synthesize on most architectures, and otherwise memset is usually very
efficient. For values which aren't entirely repeated byte patterns, LLVM
will often generate code which does memset + a few stores.
2. Zero initialization
Zero initialize all values. This has the unfortunate side-effect of
providing semantics to otherwise undefined behavior, programs therefore
might start to rely on this behavior, and that's sad. However, some
programmers believe that pattern initialization is too expensive for them,
and data might show that they're right. The only way to make these
programmers wrong is to offer zero-initialization as an option, figure out
where they are right, and optimize the compiler into submission. Until the
compiler provides acceptable performance for all security-minded code, zero
initialization is a useful (if blunt) tool.
I've been asked for a fourth initialization option: user-provided byte value.
This might be useful, and can easily be added later.
Why is an out-of band initialization mecanism desired? We could instead use
-Wuninitialized! Indeed we could, but then we're forcing the programmer to
provide semantics for something which doesn't actually have any (it's
uninitialized!). It's then unclear whether `int derp = 0;` lends meaning to `0`,
or whether it's just there to shut that warning up. It's also way easier to use
a compiler flag than it is to manually and intelligently initialize all values
in a program.
Why not just rely on static analysis? Because it cannot reason about all dynamic
code paths effectively, and it has false positives. It's a great tool, could get
even better, but it's simply incapable of catching all uses of uninitialized
values.
Why not just rely on memory sanitizer? Because it's not universally available,
has a 3x performance cost, and shouldn't be deployed in production. Again, it's
a great tool, it'll find the dynamic uses of uninitialized variables that your
test coverage hits, but it won't find the ones that you encounter in production.
What's the performance like? Not too bad! Previous publications [0] have cited
2.7 to 4.5% averages. We've commmitted a few patches over the last few months to
address specific regressions, both in code size and performance. In all cases,
the optimizations are generally useful, but variable initialization benefits
from them a lot more than regular code does. We've got a handful of other
optimizations in mind, but the code is in good enough shape and has found enough
latent issues that it's a good time to get the change reviewed, checked in, and
have others kick the tires. We'll continue reducing overheads as we try this out
on diverse codebases.
Is it a good idea? Security-minded folks think so, and apparently so does the
Microsoft Visual Studio team [1] who say "Between 2017 and mid 2018, this
feature would have killed 49 MSRC cases that involved uninitialized struct data
leaking across a trust boundary. It would have also mitigated a number of bugs
involving uninitialized struct data being used directly.". They seem to use pure
zero initialization, and claim to have taken the overheads down to within noise.
Don't just trust Microsoft though, here's another relevant person asking for
this [2]. It's been proposed for GCC [3] and LLVM [4] before.
What are the caveats? A few!
- Variables declared in unreachable code, and used later, aren't initialized.
This goto, Duff's device, other objectionable uses of switch. This should
instead be a hard-error in any serious codebase.
- Volatile stack variables are still weird. That's pre-existing, it's really
the language's fault and this patch keeps it weird. We should deprecate
volatile [5].
- As noted above, padding isn't fully handled yet.
I don't think these caveats make the patch untenable because they can be
addressed separately.
Should this be on by default? Maybe, in some circumstances. It's a conversation
we can have when we've tried it out sufficiently, and we're confident that we've
eliminated enough of the overheads that most codebases would want to opt-in.
Let's keep our precious undefined behavior until that point in time.
How do I use it:
1. On the command-line:
-ftrivial-auto-var-init=uninitialized (the default)
-ftrivial-auto-var-init=pattern
-ftrivial-auto-var-init=zero -enable-trivial-auto-var-init-zero-knowing-it-will-be-removed-from-clang
2. Using an attribute:
int dont_initialize_me __attribute((uninitialized));
[0]: https://users.elis.ugent.be/~jsartor/researchDocs/OOPSLA2011Zero-submit.pdf
[1]: https://twitter.com/JosephBialek/status/1062774315098112001
[2]: https://outflux.net/slides/2018/lss/danger.pdf
[3]: https://gcc.gnu.org/ml/gcc-patches/2014-06/msg00615.html
[4]: 776a0955ef
[5]: http://wg21.link/p1152
I've also posted an RFC to cfe-dev: http://lists.llvm.org/pipermail/cfe-dev/2018-November/060172.html
<rdar://problem/39131435>
Reviewers: pcc, kcc, rsmith
Subscribers: JDevlieghere, jkorous, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D54604
llvm-svn: 349442
Now that MSVC compatibility versions are stored as a four digit number
(1912) instead of a two digit number (19), we need to adjust how we
handle this attribute.
Also add a new test that was intended to be part of r349414.
llvm-svn: 349415
This matches what GCC does in these situations.
This fixes compiling Qt in debug mode. In release mode, references to
the vtable of this particular class ends up optimized away, but in debug
mode, the compiler creates references to the vtable, which is expected
to be dllexported from a different DLL. Make sure the dllexported
version actually ends up emitted.
Differential Revision: https://reviews.llvm.org/D55698
llvm-svn: 349256
Summary:
GCC 5.1 began mangling these Windows calling conventions into function
types, since they can be used for overloading. They've always been
mangled in the MS ABI, but they are new to the Itanium mangler. Note
that the calling convention doesn't appear as part of the main
declaration, it only appears on function parameter types and other
types.
Fixes PR39860
Reviewers: rjmccall, efriedma
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D55672
llvm-svn: 349212
All of the symbols demangle on llvm-undname and demangler.com. This
address space qualifier is useful for when we want to use opencl C++ in
Windows mode. Additionally, C++ address-space using functions will now
be usable on windows.
Differential Revision: https://reviews.llvm.org/D55715
Change-Id: Ife4506613c3cce778a783456d62117fbf7d83c26
llvm-svn: 349209
Summary:
This patch adds `__builtin_launder`, which is required to implement `std::launder`. Additionally GCC provides `__builtin_launder`, so thing brings Clang in-line with GCC.
I'm not exactly sure what magic `__builtin_launder` requires, but based on previous discussions this patch applies a `@llvm.invariant.group.barrier`. As noted in previous discussions, this may not be enough to correctly handle vtables.
Reviewers: rnk, majnemer, rsmith
Reviewed By: rsmith
Subscribers: kristina, Romain-Geissler-1A, erichkeane, amharc, jroelofs, cfe-commits, Prazek
Differential Revision: https://reviews.llvm.org/D40218
llvm-svn: 349195
The previous assertion was relatively easy to trigger, and likely will
be easy to trigger going forward. EmitDelegateCallArg is relatively
popular.
This cleanly diagnoses PR28299 while I work on a proper solution.
llvm-svn: 348991
Inline cpu_specific versions referenced before the cpu_dispatch function
weren't properly emitted, since they hadn't been referred to. This
patch ensures that during resolver generation that all appropriate
versions are emitted.
Change-Id: I94c3766aaf9c75ca07a0ad8258efdbb834654ff8
llvm-svn: 348600
This reverts commit 65df29f9318ac13a633c0ce13b2b0bccf06e79ca.
AS suggested by @rsmith here: https://reviews.llvm.org/rL345839
I'm reverting this and solving the initial problem in a different way.
llvm-svn: 348595
Thunks that return member pointers via sret are broken due to using temporary
storage for the return value on the stack and then passing that pointer to a
tail call, violating the rule that a tail call can't access allocas in the
caller (see bug).
Since r90526, we put aggregate return values directly in the sret slot, but
this doesn't apply to member pointers which are considered scalar.
Unless I'm missing something subtle, we should be able to always use the sret
slot directly for indirect return values.
Differential revision: https://reviews.llvm.org/D55371
llvm-svn: 348569
This adds a callback to PrintingPolicy to allow CGDebugInfo to remap
file paths according to -fdebug-prefix-map. Otherwise the debug info
(particularly function names for C++ lambdas) may contain paths that
should have been remapped in the debug info.
<rdar://problem/46128056>
Differential Revision: https://reviews.llvm.org/D55137
llvm-svn: 348397
This patch addresses a compilation error with clang when
running in Haiku being unable to compile code using
float128 (throws compilation error such as 'float128 is
not supported on this target').
Patch by kallisti5 (Alexander von Gluck IV)
Differential Revision: https://reviews.llvm.org/D54901
llvm-svn: 348368
As of rev. 268898, clang supports __float128 on SystemZ. This seems to
have been in error. GCC has never supported __float128 on SystemZ,
since the "long double" type on the platform is already IEEE-128. (GCC
only supports __float128 on platforms where "long double" is some other
data type.)
For compatibility reasons this patch removes __float128 on SystemZ
again. The test case is updated accordingly.
llvm-svn: 348247
This adds a callback to PrintingPolicy to allow CGDebugInfo to remap
file paths according to -fdebug-prefix-map. Otherwise the debug info
(particularly function names for C++ lambdas) may contain paths that
should have been remapped in the debug info.
<rdar://problem/46128056>
Differential Revision: https://reviews.llvm.org/D55137
llvm-svn: 348060
It seems the two failing tests can be simply fixed after r348037
Fix 3 cases in Analysis/builtin-functions.cpp
Delete the bad CodeGen/builtin-constant-p.c for now
llvm-svn: 348053
Kept the "indirect_builtin_constant_p" test case in test/SemaCXX/constant-expression-cxx1y.cpp
while we are investigating why the following snippet fails:
extern char extern_var;
struct { int a; } a = {__builtin_constant_p(extern_var)};
llvm-svn: 348039
Function calls without a !dbg location inside a function that has a
DISubprogram make it impossible to construct inline information and
are rejected by the verifier. This patch ensures that sanitizer check
function calls have a !dbg location, by carrying forward the location
of the preceding instruction or by inserting an artificial location if
necessary.
This fixes a crash when compiling the attached testcase with -Os.
rdar://problem/45311226
Differential Revision: https://reviews.llvm.org/D53459
Note: This reapllies r344915, modified to reuse the IRBuilder's
DebugLoc if one exists instead of picking the one from CGDebugInfo
since the latter may get reset when emitting thunks such as block
helpers in the middle of emitting another function.
llvm-svn: 347810
This was reverted in r347656 due to me thinking it caused a miscompile of
Chromium. Turns out it was the Chromium code that was broken.
llvm-svn: 347756
Summary:
This fixes a miscompile where we'd emit a VTT for a class that ends up
referencing an inline virtual member function that we can't actually
emit a body for (because we never instantiated it in the current TU),
which in a corner case of a corner case can lead to link errors.
Reviewers: rjmccall
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D54768
llvm-svn: 347692
This caused a miscompile in Chrome (see crbug.com/908372) that's
illustrated by this small reduction:
static bool f(int *a, int *b) {
return !__builtin_constant_p(b - a) || (!(b - a));
}
int arr[] = {1,2,3};
bool g() {
return f(arr, arr + 3);
}
$ clang -O2 -S -emit-llvm a.cc -o -
g() should return true, but after r347417 it became false for some reason.
This also reverts the follow-up commits.
r347417:
> Re-Reinstate 347294 with a fix for the failures.
>
> Don't try to emit a scalar expression for a non-scalar argument to
> __builtin_constant_p().
>
> Third time's a charm!
r347446:
> The result of is.constant() is unsigned.
r347480:
> A __builtin_constant_p() returns 0 with a function type.
r347512:
> isEvaluatable() implies a constant context.
>
> Assume that we're in a constant context if we're asking if the expression can
> be compiled into a constant initializer. This fixes the issue where a
> __builtin_constant_p() in a compound literal was diagnosed as not being
> constant, even though it's always possible to convert the builtin into a
> constant.
r347531:
> A "constexpr" is evaluated in a constant context. Make sure this is reflected
> if a __builtin_constant_p() is a part of a constexpr.
llvm-svn: 347656
Summary:
Experience has shown that the functionality is useful. It makes linking
optimized clang with debug info for me a lot faster, 20s to 13s. The
type merging phase of PDB writing goes from 10s to 3s.
This removes the LLVM cl::opt and replaces it with a metadata flag.
After this change, users can do the following to use ghash:
- add -gcodeview-ghash to compiler flags
- replace /DEBUG with /DEBUG:GHASH in linker flags
Reviewers: zturner, hans, thakis, takuto.ikuta
Subscribers: aprantl, hiraditya, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D54370
llvm-svn: 347072
Summary: The name of the synthesized constants for constant initialization was using mangling for statics, which isn't generally correct and (in a yet-uncommitted patch) causes the mangler to assert out because the static ends up trying to mangle function parameters and this makes no sense. Instead, mangle to `"__const." + FunctionName + "." + DeclName`.
Reviewers: rjmccall
Subscribers: dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D54055
llvm-svn: 346915
Reid Kleckner