(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
Summary:
If you're using the Microsoft ABI, chances are that you want PDBs and
codeview debug info. Currently, everyone has to remember to specific
-gcodeview by default, when it would be nice if the standard -g option
did the right thing by default.
Also, do some related cleanup of -cc1 options. When targetting the MS
C++ ABI, we probably shouldn't pass -debugger-tuning=gdb. We were also
passing -gcodeview twice, which is silly.
Reviewers: smeenai, zturner
Subscribers: aprantl, JDevlieghere, llvm-commits
Differential Revision: https://reviews.llvm.org/D54499
llvm-svn: 346907
Summary:
Class with no user-defined destructor that has an inherited member that has a
non-trivial destructor and a non-default constructor will attempt to emit a
destructor despite being marked as __attribute((no_destroy)) in which case it
would trigger an assertion due to an incorrect assumption.
In addition this adds missing test coverage for IR generation for no_destroy.
(Note that here use of no_destroy is synonymous with its global flag
counterpart `-fno-c++-static-destructors` being enabled)
Differential Revision: https://reviews.llvm.org/D54344
llvm-svn: 346628
The artificial variable describing the array size is supposed to be
called "__vla_expr", but this was implemented by retrieving the name
of the associated alloca, which isn't a reliable source for the name,
since nonassert compilers may drop names from LLVM IR.
rdar://problem/45924808
llvm-svn: 346542
Coerced load/stores through memory do not take into account potential
address space differences when it creates its bitcasts.
Patch by David Salinas.
Differential Revision: https://reviews.llvm.org/D53780
llvm-svn: 346413
The test hits stack overflow trying to instantiate recursive templates.
It is observed with ASAN and not with a regular build because ASAN
increases stack frame size.
rdar://problem/45009892
Reviewers: george.karpenkov, lebedev.ri
Reviewed By: george.karpenkov
Subscribers: dexonsmith, rjmccall, cfe-commits
Differential Revision: https://reviews.llvm.org/D54132
llvm-svn: 346200
Summary:
This CL adds /Zc:DllexportInlines flag to clang-cl.
When Zc:DllexportInlines- is specified, inline class member function is not exported if the function does not have local static variables.
By not exporting inline function, code for those functions are not generated and that reduces both compile time and obj size. Also this flag does not import inline functions from dllimported class if the function does not have local static variables.
On my 24C48T windows10 machine, build performance of chrome target in chromium repository is like below.
These stats are come with 'target_cpu="x86" enable_nacl = false is_component_build=true dcheck_always_on=true` build config and applied
* https://chromium-review.googlesource.com/c/chromium/src/+/1212379
* https://chromium-review.googlesource.com/c/v8/v8/+/1186017
Below stats were taken with this patch applied on a05115cd4c
| config | build time | speedup | build dir size |
| with patch, PCH on, debug | 1h10m0s | x1.13 | 35.6GB |
| without patch, PCH on, debug | 1h19m17s | | 49.0GB |
| with patch, PCH off, debug | 1h15m45s | x1.16 | 33.7GB |
| without patch, PCH off, debug | 1h28m10s | | 52.3GB |
| with patch, PCH on, release | 1h13m13s | x1.22 | 26.2GB |
| without patch, PCH on, release | 1h29m57s | | 37.5GB |
| with patch, PCH off, release | 1h23m38s | x1.32 | 23.7GB |
| without patch, PCH off, release | 1h50m50s | | 38.7GB |
This patch reduced obj size and the number of exported symbols largely, that improved link time too.
e.g. link time stats of blink_core.dll become like below
| | cold disk cache | warm disk cache |
| with patch, PCH on, debug | 71s | 30s |
| without patch, PCH on, debug | 111s | 48s |
This patch's implementation is based on Nico Weber's patch. I modified to support static local variable, added tests and took stats.
Bug: https://bugs.llvm.org/show_bug.cgi?id=33628
Reviewers: hans, thakis, rnk, javed.absar
Reviewed By: hans
Subscribers: kristof.beyls, smeenai, dschuff, probinson, cfe-commits, eraman
Differential Revision: https://reviews.llvm.org/D51340
llvm-svn: 346069
This exposes a (known) CodeGen bug: it can't cope with emitting lvalue
expressions that denote non-odr-used but usable-in-constant-expression
variables. See PR39528 for a testcase.
Reverted for now until that issue can be fixed.
llvm-svn: 346065
Multiverson function versions are always used (by the resolver), so ensure that
they are always emitted.
Change-Id: I5d2e0841fddf0d18918b3fb92ae76814add7ee96
llvm-svn: 345839
The member type creation for a cpu-dispatch function was not correctly
including the 'this' parameter, so ensure that the type is properly
determined. Also, disable defer in the cases of emitting the functoins,
as it can end up resulting in the wrong version being emitted.
Change-Id: I0b8fc5e0b0d1ae1a9d98fd54f35f27f6e5d5d083
llvm-svn: 345838
__tls_guard.
__tls_guard can only ever transition from 0 to 1, and only once. This
permits LLVM to remove repeated checks for TLS initialization and
repeated initialization code in cases like:
int g();
thread_local int n = g();
int a = n + n;
where we could not prove that __tls_guard was still 'true' when checking
it for the second reference to 'n' in the initializer of 'a'.
llvm-svn: 345774
Calling it too early might cause dllimport to get inherited onto the
VarDecl before the initializer got attached. See the test case for an
example where this broke things.
llvm-svn: 345709
In the course of D51340, @takuto.ikuta discovered that Clang fails to put
dllexport/import attributes on static locals during template instantiation.
For regular functions, this happens in Sema::FinalizeDeclaration(), however for
template instantiations we need to do something in or around
TemplateDeclInstantiator::VisitVarDecl(). This patch does that, and extracts
the code to a utility function.
Differential Revision: https://reviews.llvm.org/D53870
llvm-svn: 345699
This is the second half of Implicit Integer Conversion Sanitizer.
It completes the first half, and finally makes the sanitizer
fully functional! Only the bitfield handling is missing.
Summary:
C and C++ are interesting languages. They are statically typed, but weakly.
The implicit conversions are allowed. This is nice, allows to write code
while balancing between getting drowned in everything being convertible,
and nothing being convertible. As usual, this comes with a price:
```
void consume(unsigned int val);
void test(int val) {
consume(val);
// The 'val' is `signed int`, but `consume()` takes `unsigned int`.
// If val is negative, then consume() will be operating on a large
// unsigned value, and you may or may not have a bug.
// But yes, sometimes this is intentional.
// Making the conversion explicit silences the sanitizer.
consume((unsigned int)val);
}
```
Yes, there is a `-Wsign-conversion`` diagnostic group, but first, it is kinda
noisy, since it warns on everything (unlike sanitizers, warning on an
actual issues), and second, likely there are cases where it does **not** warn.
The actual detection is pretty easy. We just need to check each of the values
whether it is negative, and equality-compare the results of those comparisons.
The unsigned value is obviously non-negative. Zero is non-negative too.
https://godbolt.org/g/w93oj2
We do not have to emit the check *always*, there are obvious situations
where we can avoid emitting it, since it would **always** get optimized-out.
But i do think the tautological IR (`icmp ult %x, 0`, which is always false)
should be emitted, and the middle-end should cleanup it.
This sanitizer is in the `-fsanitize=implicit-conversion` group,
and is a logical continuation of D48958 `-fsanitize=implicit-integer-truncation`.
As for the ordering, i'we opted to emit the check **after**
`-fsanitize=implicit-integer-truncation`. At least on these simple 16 test cases,
this results in 1 of the 12 emitted checks being optimized away,
as compared to 0 checks being optimized away if the order is reversed.
This is a clang part.
The compiler-rt part is D50251.
Finishes fixing [[ https://bugs.llvm.org/show_bug.cgi?id=21530 | PR21530 ]], [[ https://bugs.llvm.org/show_bug.cgi?id=37552 | PR37552 ]], [[ https://bugs.llvm.org/show_bug.cgi?id=35409 | PR35409 ]].
Finishes partially fixing [[ https://bugs.llvm.org/show_bug.cgi?id=9821 | PR9821 ]].
Finishes fixing https://github.com/google/sanitizers/issues/940.
Only the bitfield handling is missing.
Reviewers: vsk, rsmith, rjmccall, #sanitizers, erichkeane
Reviewed By: rsmith
Subscribers: chandlerc, filcab, cfe-commits, regehr
Tags: #sanitizers, #clang
Differential Revision: https://reviews.llvm.org/D50250
llvm-svn: 345660
nullptr_t does not access memory.
We now reuse CK_NullToPointer to represent a conversion from a glvalue
of type nullptr_t to a prvalue of nullptr_t where necessary.
llvm-svn: 345562
We correctly handled extended vectors of non-floating point types.
However, we have the Intel style builtins which MSVC also supports which
do overlap in sizes with the floating point extended vectors. This
would result in overloading of floating point extended vector types
which matched sizes (e.g. <3 x float> would be backed by a <4 x float>
and thus match sizes) to be mangled similarly. Extended vectors are a
clang extension which live outside of the builtins, so mangle them all
similarly. This change just extends the current scheme to treat
floating point types similar to the way that we treat other types
currently.
This now allows the swift runtime to be built for Windows again.
llvm-svn: 345479
The generated MS manglings differ between 32- and 64-bit, and the test only
expects the latter. See also the commit email thread.
> Thanks to Cameron DaCamara at Microsoft for letting us know what their
> chosen mangling is here!
llvm-svn: 345380
Similar to how ICC handles CPU-Dispatch on Windows, this patch uses the
resolver function directly to forward the call to the proper function.
This is not nearly as efficient as IFuncs of course, but is still quite
useful for large functions specifically developed for certain
processors.
This is unfortunately still limited to x86, since it depends on
__builtin_cpu_supports and __builtin_cpu_is, which are x86 builtins.
The naming for the resolver/forwarding function for cpu-dispatch was
taken from ICC's implementation, which uses the unmodified name for this
(no mangling additions). This is possible, since cpu-dispatch uses '.A'
for the 'default' version.
In 'target' multiversioning, this function keeps the '.resolver'
extension in order to keep the default function keeping the default
mangling.
Change-Id: I4731555a39be26c7ad59a2d8fda6fa1a50f73284
Differential Revision: https://reviews.llvm.org/D53586
llvm-svn: 345298
an external layout is used
Summary:
The patch removes alignment of virtual bases when an external layout is used.
We have two cases:
- the external layout source has an information about virtual bases offsets,
so we just use them;
- the external source has no information about virtual bases offsets. In this
case we can't predict where the base will be located. If we will align it but
there will be something like `#pragma pack(push, 1)` really, then likely our
layout will not fit into the real structure size, and then some asserts will
hit. The asserts look reasonable, so I don't think that we need to remove
them. May be it would be better instead don't align fields / bases etc.
(so treat it always as `#pragma pack(push, 1)`) when an external layout source
is used but no info about a field location is presented.
This one is related to D49871
Reviewers: rnk, rsmith, zturner, mstorsjo, majnemer
Reviewed By: rnk
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D53497
llvm-svn: 345012
For instantiated functions, search the template pattern to see if it marked
inline to determine if InlineHint attribute should be added to the function.
llvm-svn: 344987
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
llvm-svn: 344915
Rather, they are subexpressions of the enclosing lambda-expression, and
any temporaries in them are destroyed at the end of that
full-expression, or when the corresponding lambda-expression is
destroyed if they are lifetime-extended.
llvm-svn: 344801
This reverts commit https://reviews.llvm.org/rL344150 which causes
MachineOutliner related failures on the ppc64le multistage buildbot.
llvm-svn: 344526
Summary:
As per IRC disscussion, it seems we really want to have more fine-grained `-fsanitize=implicit-integer-truncation`:
* A check when both of the types are unsigned.
* Another check for the other cases (either one of the types is signed, or both of the types is signed).
This is clang part.
Compiler-rt part is D50902.
Reviewers: rsmith, vsk, Sanitizers
Reviewed by: rsmith
Differential Revision: https://reviews.llvm.org/D50901
llvm-svn: 344230
This can be used to preserve profiling information across codebase
changes that have widespread impact on mangled names, but across which
most profiling data should still be usable. For example, when switching
from libstdc++ to libc++, or from the old libstdc++ ABI to the new ABI,
or even from a 32-bit to a 64-bit build.
The user can provide a remapping file specifying parts of mangled names
that should be treated as equivalent (eg, std::__1 should be treated as
equivalent to std::__cxx11), and profile data will be treated as
applying to a particular function if its name is equivalent to the name
of a function in the profile data under the provided equivalences. See
the documentation change for a description of how this is configured.
Remapping is supported for both sample-based profiling and instruction
profiling. We do not support remapping indirect branch target
information, but all other profile data should be remapped
appropriately.
Support is only added for the new pass manager. If someone wants to also
add support for this for the old pass manager, doing so should be
straightforward.
llvm-svn: 344199
Summary:
In r340386 we added code to give static locals in inline functions
default visibility. Instead, we should use the "default" visibility
passed on the command line, which could be hidden or protected, as GCC
does.
Some code bases use both -fvisibility=hidden and
-fvisibility-inlines-hidden to hide inline functions of classes that are
explicitly marked with default visibility.
Fixes PR39236
Reviewers: hans, thakis
Subscribers: eraman, llvm-commits
Differential Revision: https://reviews.llvm.org/D53052
llvm-svn: 344190
This is currently a clang extension and a resolution
of the defect report in the C++ Standard.
Differential Revision: https://reviews.llvm.org/D46441
llvm-svn: 344150
DWARF v5 introduces DW_AT_call_all_calls, a subprogram attribute which
indicates that all calls (both regular and tail) within the subprogram
have call site entries. The information within these call site entries
can be used by a debugger to populate backtraces with synthetic tail
call frames.
Tail calling frames go missing in backtraces because the frame of the
caller is reused by the callee. Call site entries allow a debugger to
reconstruct a sequence of (tail) calls which led from one function to
another. This improves backtrace quality. There are limitations: tail
recursion isn't handled, variables within synthetic frames may not
survive to be inspected, etc. This approach is not novel, see:
https://gcc.gnu.org/wiki/summit2010?action=AttachFile&do=get&target=jelinek.pdf
This patch adds an IR-level flag (DIFlagAllCallsDescribed) which lowers
to DW_AT_call_all_calls. It adds the minimal amount of DWARF generation
support needed to emit standards-compliant call site entries. For easier
deployment, when the debugger tuning is LLDB, the DWARF requirement is
adjusted to v4.
Testing: Apart from check-{llvm, clang}, I built a stage2 RelWithDebInfo
clang binary. Its dSYM passed verification and grew by 1.4% compared to
the baseline. 151,879 call site entries were added.
rdar://42001377
Differential Revision: https://reviews.llvm.org/D49887
llvm-svn: 343883
Summary:
This attribute allows excluding a member of a class template from being part
of an explicit template instantiation of that class template. This also makes
sure that code using such a member will not take for granted that an external
instantiation exists in another translation unit. The attribute was discussed
on cfe-dev at [1] and is primarily motivated by the removal of always_inline
in libc++ to control what's part of the ABI (see links in [1]).
[1]: http://lists.llvm.org/pipermail/cfe-dev/2018-August/059024.html
rdar://problem/43428125
Reviewers: rsmith
Subscribers: dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D51789
llvm-svn: 343790
Summary: Add an optional attribute referring to a tuple of type and value template parameter nodes to the DIGlobalVariable node. This allows us to record the parameters of template variable specializations.
Reviewers: dblaikie, aprantl, probinson, JDevlieghere, clayborg, jingham
Reviewed By: JDevlieghere
Subscribers: cfe-commits
Tags: #debug-info
Differential Revision: https://reviews.llvm.org/D52058
llvm-svn: 343707
from those that aren't.
This patch changes the way __block variables that aren't captured by
escaping blocks are handled:
- Since non-escaping blocks on the stack never get copied to the heap
(see https://reviews.llvm.org/D49303), Sema shouldn't error out when
the type of a non-escaping __block variable doesn't have an accessible
copy constructor.
- IRGen doesn't have to use the specialized byref structure (see
https://clang.llvm.org/docs/Block-ABI-Apple.html#id8) for a
non-escaping __block variable anymore. Instead IRGen can emit the
variable as a normal variable and copy the reference to the block
literal. Byref copy/dispose helpers aren't needed either.
This reapplies r343518 after fixing a use-after-free bug in function
Sema::ActOnBlockStmtExpr where the BlockScopeInfo was dereferenced after
it was popped and deleted.
rdar://problem/39352313
Differential Revision: https://reviews.llvm.org/D51564
llvm-svn: 343542
from those that aren't.
This patch changes the way __block variables that aren't captured by
escaping blocks are handled:
- Since non-escaping blocks on the stack never get copied to the heap
(see https://reviews.llvm.org/D49303), Sema shouldn't error out when
the type of a non-escaping __block variable doesn't have an accessible
copy constructor.
- IRGen doesn't have to use the specialized byref structure (see
https://clang.llvm.org/docs/Block-ABI-Apple.html#id8) for a
non-escaping __block variable anymore. Instead IRGen can emit the
variable as a normal variable and copy the reference to the block
literal. Byref copy/dispose helpers aren't needed either.
This reapplies r341754, which was reverted in r341757 because it broke a
couple of bots. r341754 was calling markEscapingByrefs after the call to
PopFunctionScopeInfo, which caused the popped function scope to be
cleared out when the following code was compiled, for example:
$ cat test.m
struct A {
id data[10];
};
void foo() {
__block A v;
^{ (void)v; };
}
This commit calls markEscapingByrefs before calling PopFunctionScopeInfo
to prevent that from happening.
rdar://problem/39352313
Differential Revision: https://reviews.llvm.org/D51564
llvm-svn: 343518
Summary:
Some lines have a hit counter where they should not have one.
Cleanup stuff is located to the last line of the body which is most of the time a '}'.
And Exception stuff is added at the beginning of a function and at the end (represented by '{' and '}').
So in such cases, the DebugLoc used in GCOVProfiling.cpp must be marked as not covered.
This patch is a followup of https://reviews.llvm.org/D49915.
Tests in projects/compiler_rt are fixed by: https://reviews.llvm.org/D49917
Reviewers: marco-c, davidxl
Reviewed By: marco-c
Subscribers: dblaikie, cfe-commits, sylvestre.ledru
Differential Revision: https://reviews.llvm.org/D49916
llvm-svn: 342717
A lambda's closure is initialized when the lambda is declared. For
implicit captures, the initialization code emitted from EmitLambdaExpr
references source locations *within the lambda body* in the function
containing the lambda. This results in a poor debugging experience: we
step to the line containing the lambda, then into lambda, out again,
over and over, until every capture's field is initialized.
To improve stepping behavior, assign the starting location of the lambda
to expressions which initialize an implicit capture within it.
rdar://39807527
Differential Revision: https://reviews.llvm.org/D50927
llvm-svn: 342194
Functions generated by clang and included in the .init_array section (such as
static constructors) do not follow the usual code path for adding
target-specific function attributes, so we have to add the return address
signing attribute here too, as is currently done for the sanitisers.
Differential revision: https://reviews.llvm.org/D51418
llvm-svn: 342126
Previously the alignment on the newly created rtti/typeinfo data was largely
not set, meaning that DataLayout::getPreferredAlignment was free to overalign
it to 16 bytes. This causes unnecessary code bloat.
Differential Revision: https://reviews.llvm.org/D51416
llvm-svn: 342053
from those that aren't.
This patch changes the way __block variables that aren't captured by
escaping blocks are handled:
- Since non-escaping blocks on the stack never get copied to the heap
(see https://reviews.llvm.org/D49303), Sema shouldn't error out when
the type of a non-escaping __block variable doesn't have an accessible
copy constructor.
- IRGen doesn't have to use the specialized byref structure (see
https://clang.llvm.org/docs/Block-ABI-Apple.html#id8) for a
non-escaping __block variable anymore. Instead IRGen can emit the
variable as a normal variable and copy the reference to the block
literal. Byref copy/dispose helpers aren't needed either.
rdar://problem/39352313
Differential Revision: https://reviews.llvm.org/D51564
llvm-svn: 341754
I changed the seed slightly, but forgot to run the tests on a 32-bit system, so
tests which hard-code a specific hash value started breaking.
llvm-svn: 341240
Summary:
Added option -gline-directives-only to support emission of the debug directives
only. It behaves very similar to -gline-tables-only, except that it sets
llvm debug info emission kind to
llvm::DICompileUnit::DebugDirectivesOnly.
Reviewers: echristo
Subscribers: aprantl, fedor.sergeev, JDevlieghere, cfe-commits
Differential Revision: https://reviews.llvm.org/D51177
llvm-svn: 341212
There are two types of dynamic initializer stubs. There's
`dynamic initializer for 'x''(void)
and
`dynamic initializer for `static Foo::Bar StaticDataMember''(void)
The second case is disambiguated from the first by the presence of
a ? after the operator code. So the first will appear something like
?__E<name> while the second will appear something like ?__E?<name>.
clang-cl was mangling these both the same though. This patch
matches behavior with cl.
Differential Revision: https://reviews.llvm.org/D51500
llvm-svn: 341117
Since MinGW supports automatically importing external variables from
DLLs even without the DLLImport attribute, we shouldn't mark them
as DSO local unless we actually know them to be local for sure.
Keep marking thread local variables as DSO local.
Differential Revision: https://reviews.llvm.org/D51382
llvm-svn: 340941
This patch removes uses of the Darwin ABI for PowerPC related test cases. This
is the first step in removing Darwin support from the POWER backend.
clang/test/CodeGen/darwin-ppc-varargs.c was deleted because it was a darwin/ppc
specific test case.
All other tests were updated to remove the darwin/ppc specific invocation.
Phabricator Review: https://reviews.llvm.org/D50989.
llvm-svn: 340770
As reported on http://lists.llvm.org/pipermail/cfe-dev/2018-August/058760.html,
this broke i386-freebsd11 due to its lack of atomic 64 bit primitives.
While that's not really this commit's fault, let's revert back to the old
behaviour until this can be fixed. This means generating cmpxchg8b etc for i386
and i486 which don't technically support those, but that's been the behaviour
for a long time, so a little longer probably doesn't hurt that much.
> Adjust MaxAtomicInlineWidth for i386/i486 targets.
>
> This is to fix the bug reported in https://bugs.llvm.org/show_bug.cgi?id=34347#c6.
> Currently, all MaxAtomicInlineWidth of x86-32 targets are set to 64. However,
> i386 doesn't support any cmpxchg related instructions. i486 only supports cmpxchg.
> So in this patch MaxAtomicInlineWidth is reset as follows:
> For i386, the MaxAtomicInlineWidth should be 0 because no cmpxchg is supported.
> For i486, the MaxAtomicInlineWidth should be 32 because it supports cmpxchg.
> For others 32 bits x86 cpu, the MaxAtomicInlineWidth should be 64 because of cmpxchg8b.
>
> Differential Revision: https://reviews.llvm.org/D42154
llvm-svn: 340666
The command line option -fvisibility-inlines-hidden makes inlined method hidden, but it is expected not to affect the visibility of static local variables in the function.
However, Clang makes the static local variables in the function also hidden as reported in PR37595. This problem causes LLVM bootstarp failure on Fedora 28 if configured with -DBUILD_SHARED_LIBS=ON.
This patch makes the behavior of -fvisibility-inlines-hidden option to be consistent with that of gcc; the option does not change the visibility of the static local variables if the containing function does not associated with explicit visibility attribute and becomes hidden due to this option.
Differential Revision: https://reviews.llvm.org/D50968
llvm-svn: 340386
This commit adds the flag -fno-c++-static-destructors and the attributes
[[clang::no_destroy]] and [[clang::always_destroy]]. no_destroy specifies that a
specific static or thread duration variable shouldn't have it's destructor
registered, and is the default in -fno-c++-static-destructors mode.
always_destroy is the opposite, and is the default in -fc++-static-destructors
mode.
A variable whose destructor is disabled (either because of
-fno-c++-static-destructors or [[clang::no_destroy]]) doesn't count as a use of
the destructor, so we don't do any access checking or mark it referenced. We
also don't emit -Wexit-time-destructors for these variables.
rdar://21734598
Differential revision: https://reviews.llvm.org/D50994
llvm-svn: 340306
by a block.
Added checks for capturing of the variable in the block when trying to
emit correct address for the variable with the reference type. This
extra check allows correctly identify the variables that are not
captured in the block context.
llvm-svn: 340181
Summary:
This is needed to avoid conflicts in mangled names for codeview types in
anonymous namespaces. In CodeView, types refer to each other typically
through forward declarations, which contain mangled names. These names
have to be unique, otherwise the debugger will look up the mangled name
and find the wrong definition.
Furthermore, ThinLTO will deduplicate the types, and debug info
verification can fail when the types have the wrong sizes. This is
PR38608.
Fixes PR38609.
Reviewers: majnemer, inglorion, hans
Subscribers: mehdi_amini, aprantl, JDevlieghere, dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D50877
llvm-svn: 340079
Currently, clang generates a new block descriptor global variable for
each new block literal. This commit merges block descriptors that are
identical inside and across translation units using the same approach
taken in r339438.
To enable merging identical block descriptors, the size and signature of
the block and information about the captures are encoded into the name
of the block descriptor variable. Also, the block descriptor variable is
marked as linkonce_odr and unnamed_addr.
rdar://problem/42640703
Differential Revision: https://reviews.llvm.org/D50783
llvm-svn: 340041
Multiversioned member functions inside of a template type were
not properly being emitted. The solution to this is to simply
ensure that their bodies are correctly evaluated/assigned during
template instantiation.
llvm-svn: 339597
Clang generates copy and dispose helper functions for each block literal
on the stack. Often these functions are equivalent for different blocks.
This commit makes changes to merge equivalent copy and dispose helper
functions and reduce code size.
To enable merging equivalent copy/dispose functions, the captured object
infomation is encoded into the helper function name. This allows IRGen
to check whether an equivalent helper function has already been emitted
and reuse the function instead of generating a new helper function
whenever a block is defined. In addition, the helper functions are
marked as linkonce_odr to enable merging helper functions that have the
same name across translation units and marked as unnamed_addr to enable
the linker's deduplication pass to merge functions that have different
names but the same content.
rdar://problem/42640608
Differential Revision: https://reviews.llvm.org/D50152
llvm-svn: 339438
Changes the default Windows target triple returned by
GetHostTriple.cmake from the old environment names (which we wanted to
move away from) to newer, normalized ones. This also requires updating
all tests to use the new systems names in constraints.
Differential Revision: https://reviews.llvm.org/D47381
llvm-svn: 339307
We're not actually testing for alignment, we just want to know that whatever incoming alignment got propagated. Do that by capturing the alignment and checking that it's actually what's passed later, instead of hard-coding an alignment value.
llvm-svn: 339196
It turns out that the AVX bots have different alignment for their vectors, and my test mistakenly assumed a particular vector alignent on the stack. Instead, capture the alignment and test for it in subsequent operations.
llvm-svn: 339093
Summary:
r337887 started using memset for automatic variable initialization where sensible. A follow-up discussion leads me to believe that we should better test automatic variable initialization, and that there are probably follow-up patches in clang and LLVM to improve codegen. It’ll be important to measure -O0 compile time, and figure out which transforms should be in the frontend versus the backend.
This patch is just a test of the current behavior, no questions asked. Follow-up patches will tune the code generation.
<rdar://problem/42981573>
Subscribers: dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D50361
llvm-svn: 339089
When a non-extended temporary object is created in a conditional branch, the
lifetime of that temporary ends outside the conditional (at the end of the
full-expression). If we're inserting lifetime markers, this means we could end
up generating
if (some_cond) {
lifetime.start(&tmp);
Tmp::Tmp(&tmp);
}
// ...
if (some_cond) {
lifetime.end(&tmp);
}
... for a full-expression containing a subexpression of the form `some_cond ?
Tmp().x : 0`. This patch moves the lifetime start for such a temporary out of
the conditional branch so that we don't need to generate an additional basic
block to hold the lifetime end marker.
This is disabled if we want precise lifetime markers (for asan's
stack-use-after-scope checks) or of the temporary has a non-trivial destructor
(in which case we'd generate an extra basic block anyway to hold the destructor
call).
Differential Revision: https://reviews.llvm.org/D50286
llvm-svn: 338945
Summary:
Emit !llvm.mem.parallel_loop_access metadata for memory accesses even if the parallel loop is not the top on the loop stack.
Fixes llvm.org/PR37558.
Reviewers: ABataev, hfinkel, amusman, tyler.nowicki
Reviewed By: hfinkel
Subscribers: Meinersbur, hfinkel, cfe-commits
Differential Revision: https://reviews.llvm.org/D48808
llvm-svn: 338810
Explicit cast of a void pointer to a pointer type in different address space is
incorrectly classified as bitcast, which causes invalid bitcast in codegen.
The patch fixes that by checking the address space of the source and destination
type and set the correct cast kind.
Differential Revision: https://reviews.llvm.org/D50003
llvm-svn: 338805
This adds support for the unroll_and_jam pragma, to go with the recently
added unroll and jam pass. The name of the pragma is the same as is used
in the Intel compiler, and most of the code works the same as for unroll.
#pragma clang loop unroll_and_jam has been separated into a different
patch. This part adds #pragma unroll_and_jam with an optional count, and
#pragma no_unroll_and_jam to disable the transform.
Differential Revision: https://reviews.llvm.org/D47267
llvm-svn: 338566
Summary:
rC337815 / D49508 had to cannibalize one bit of `CastExprBitfields::BasePathSize` in order to squeeze `PartOfExplicitCast` boolean.
That reduced the maximal value of `PartOfExplicitCast` from 9 bits (~512) down to 8 bits (~256).
Apparently, that mattered. Too bad there weren't any tests.
It caused [[ https://bugs.llvm.org/show_bug.cgi?id=38356 | PR38356 ]].
So we need to increase `PartOfExplicitCast` back at least to 9 bits, or a bit more.
For obvious reasons, we can't do that in `CastExprBitfields` - that would blow up the size of every `Expr`.
So we need to either just add a variable into the `CastExpr` (as done here),
or use `llvm::TrailingObjects`. The latter does not seem to be straight-forward.
Perhaps, that needs to be done not for the `CastExpr` itself, but for all of it's `final` children.
Reviewers: rjmccall, rsmith, erichkeane
Reviewed By: rjmccall
Subscribers: bricci, hans, cfe-commits, waddlesplash
Differential Revision: https://reviews.llvm.org/D50050
llvm-svn: 338489
Summary:
This patch improves support of PDB as an external layout source
in the next cases:
- Multiple non-virtual inheritance from packed base classes. When using
external layout, there's no need to align `NonVirtualSize` of a base class.
It may cause an overlapping when the next base classes will be layouted
(but there is a slightly different case in the test because I can't find
a way to specify a base offset);
- Support of nameless structs and unions. There is no info about nameless child
structs and unions in Microsoft cl-emitted PDBs. Instead all its fields
are just treated as outer structure's (union's) fields. This also causes
a fields overlapping, and makes it possible for unions to have fields located
at a non-zero offset.
Reviewers: rsmith, zturner, rnk, mstorsjo, majnemer
Reviewed By: rnk
Subscribers: cfe-commits
Tags: #clang
Differential Revision: https://reviews.llvm.org/D49871
llvm-svn: 338353
Summary:
C and C++ are interesting languages. They are statically typed, but weakly.
The implicit conversions are allowed. This is nice, allows to write code
while balancing between getting drowned in everything being convertible,
and nothing being convertible. As usual, this comes with a price:
```
unsigned char store = 0;
bool consume(unsigned int val);
void test(unsigned long val) {
if (consume(val)) {
// the 'val' is `unsigned long`, but `consume()` takes `unsigned int`.
// If their bit widths are different on this platform, the implicit
// truncation happens. And if that `unsigned long` had a value bigger
// than UINT_MAX, then you may or may not have a bug.
// Similarly, integer addition happens on `int`s, so `store` will
// be promoted to an `int`, the sum calculated (0+768=768),
// and the result demoted to `unsigned char`, and stored to `store`.
// In this case, the `store` will still be 0. Again, not always intended.
store = store + 768; // before addition, 'store' was promoted to int.
}
// But yes, sometimes this is intentional.
// You can either make the conversion explicit
(void)consume((unsigned int)val);
// or mask the value so no bits will be *implicitly* lost.
(void)consume((~((unsigned int)0)) & val);
}
```
Yes, there is a `-Wconversion`` diagnostic group, but first, it is kinda
noisy, since it warns on everything (unlike sanitizers, warning on an
actual issues), and second, there are cases where it does **not** warn.
So a Sanitizer is needed. I don't have any motivational numbers, but i know
i had this kind of problem 10-20 times, and it was never easy to track down.
The logic to detect whether an truncation has happened is pretty simple
if you think about it - https://godbolt.org/g/NEzXbb - basically, just
extend (using the new, not original!, signedness) the 'truncated' value
back to it's original width, and equality-compare it with the original value.
The most non-trivial thing here is the logic to detect whether this
`ImplicitCastExpr` AST node is **actually** an implicit conversion, //or//
part of an explicit cast. Because the explicit casts are modeled as an outer
`ExplicitCastExpr` with some `ImplicitCastExpr`'s as **direct** children.
https://godbolt.org/g/eE1GkJ
Nowadays, we can just use the new `part_of_explicit_cast` flag, which is set
on all the implicitly-added `ImplicitCastExpr`'s of an `ExplicitCastExpr`.
So if that flag is **not** set, then it is an actual implicit conversion.
As you may have noted, this isn't just named `-fsanitize=implicit-integer-truncation`.
There are potentially some more implicit conversions to be warned about.
Namely, implicit conversions that result in sign change; implicit conversion
between different floating point types, or between fp and an integer,
when again, that conversion is lossy.
One thing i know isn't handled is bitfields.
This is a clang part.
The compiler-rt part is D48959.
Fixes [[ https://bugs.llvm.org/show_bug.cgi?id=21530 | PR21530 ]], [[ https://bugs.llvm.org/show_bug.cgi?id=37552 | PR37552 ]], [[ https://bugs.llvm.org/show_bug.cgi?id=35409 | PR35409 ]].
Partially fixes [[ https://bugs.llvm.org/show_bug.cgi?id=9821 | PR9821 ]].
Fixes https://github.com/google/sanitizers/issues/940. (other than sign-changing implicit conversions)
Reviewers: rjmccall, rsmith, samsonov, pcc, vsk, eugenis, efriedma, kcc, erichkeane
Reviewed By: rsmith, vsk, erichkeane
Subscribers: erichkeane, klimek, #sanitizers, aaron.ballman, RKSimon, dtzWill, filcab, danielaustin, ygribov, dvyukov, milianw, mclow.lists, cfe-commits, regehr
Tags: #sanitizers
Differential Revision: https://reviews.llvm.org/D48958
llvm-svn: 338288
This commit increases the number of sections and overall output size of
.o files by 10% and sometimes a bit more. This alone is challenging for
some users, but it also appears to trigger an as-yet unexplained
behavior in the Gold linker where the memory usage increases
considerably more than 10% (we think).
The increase is also frustrating because in many (if not all) cases we
end up with almost all of the growth coming from the ELF overhead of
-ffunction-sections and such, not from actual extra code being emitted.
Richard Smith and Eric Christopher are both going to investigate this
and try to get to the bottom of what is triggering this and whether the
kinds of increases here are sustainable or what options we might have to
minimize the impact they have. However, this is currently breaking
a pretty large number of our users' builds so reverting it while we sort
out how to make progress here. I've seen a longer and more detailed
update to the commit thread.
llvm-svn: 338209
With this change compiler generates alignment checks for wider range
of types. Previously such checks were generated only for the record types
with non-trivial default constructor. So the types like:
struct alignas(32) S2 { int x; };
typedef __attribute__((ext_vector_type(2), aligned(32))) float float32x2_t;
did not get checks when allocated by 'new' expression.
This change also optimizes the checks generated for the arrays created
in 'new' expressions. Previously the check was generated for each
invocation of type constructor. Now the check is generated only once
for entire array.
Differential Revision: https://reviews.llvm.org/D49589
llvm-svn: 338199
in some member function calls.
Specifically, when calling a conversion function, we would fail to
create the AST node representing materialization of the class object.
llvm-svn: 338135
Summary: Microsoft's C++ object model for ARM64 is the same as that for X86_64.
For example, small structs with non-trivial copy constructors or virtual
function tables are passed indirectly. Currently, they are passed in registers
when compiled with clang.
Reviewers: rnk, mstorsjo, TomTan, haripul, javed.absar
Reviewed By: rnk, mstorsjo
Subscribers: kristof.beyls, chrib, llvm-commits, cfe-commits
Differential Revision: https://reviews.llvm.org/D49770
llvm-svn: 338076
If QMM_Result is set (which it is for return types, RTTI descriptors, and
exception type descriptors), tag types (structs, enums, classes, unions) get
their qualifiers mangled in.
__m64 and friends is a struct/union thingy in MSVC, but not in clang's headers.
To make mangling work, we call mangleArtificalTagType(TTK_Union/TTK_Struct for
the vector types to mangle them as tag types -- but the isa<TagType> check when
mangling in QMM_Result mode isn't true for these vector types. Add an
isArtificialTagType() function and check for that too. Fixes PR37276 and some
other issues.
I tried to audit all references to TagDecl and TagType in MicrosoftMangle.cpp
to find other places where we need to call mangleArtificalTagType(), but
couldn't find any.
I tried to audit all calls to mangleArtificalTagType() to see if
isArtificialTagType() needs to handle more than just the vector types, but as
far as I can tell all other types we use it for are types that MSVC can't
handle at all (Objective-C types etc).
https://reviews.llvm.org/D49597
llvm-svn: 337732
This reinstates r337627, reverted in r337671, with a fix to correctly
handle the lvalueness of array subscript expressions on pointers.
llvm-svn: 337726
This reverts commit r337627.
After the change, clang started producing invalid warning on the following code:
struct foo {
foo(char *x) : x_(&x[10]) {}
private:
char *x_;
};
1.cpp:2:21: warning: initializing pointer member 'x_' with the stack address of parameter 'x' [-Wdangling-field]
llvm-svn: 337671
MSVC doesn't, so neither should we.
Fixes PR38004, which is a crash that happens when we try to emit debug
info for a still-dependent partial variable template specialization.
As a follow-up, we should review what we're doing for function and class
member templates. It looks like we don't filter those out, but I can't
seem to get clang to emit any.
llvm-svn: 337616
Currently clang does not allow implicit cast of a pointer to a pointer type
in different address space but allows C-style cast of a pointer to a pointer
type in different address space. However, there is a bug in Sema causing
incorrect Cast Expr in AST for the latter case, which in turn results in
invalid LLVM IR in codegen.
This is because Sema::IsQualificationConversion returns true for a cast of
pointer to a pointer type in different address space, which in turn allows
a standard conversion and results in a cast expression with no op in AST.
This patch fixes that by let Sema::IsQualificationConversion returns false
for a cast of pointer to a pointer type in different address space, which
in turn disallows standard conversion, implicit cast, and static cast.
Finally it results in an reinterpret cast and correct conversion kind is set.
Differential Revision: https://reviews.llvm.org/D49294
llvm-svn: 337540
The previous version of this patch (r332839) was reverted because it was
causing "definition with same mangled name as another definition" errors
in some module builds. This was caused by an unrelated bug in module
importing which it exposed. The importing problem was fixed in r336240,
so this recommits the original patch (r332839).
Differential Revision: https://reviews.llvm.org/D46685
llvm-svn: 337456
Summary:
Support for this option is needed for building Linux kernel.
This is a very frequently requested feature by kernel developers.
More details : https://lkml.org/lkml/2018/4/4/601
GCC option description for -fdelete-null-pointer-checks:
This Assume that programs cannot safely dereference null pointers,
and that no code or data element resides at address zero.
-fno-delete-null-pointer-checks is the inverse of this implying that
null pointer dereferencing is not undefined.
This feature is implemented in as the function attribute
"null-pointer-is-valid"="true".
This CL only adds the attribute on the function.
It also strips "nonnull" attributes from function arguments but
keeps the related warnings unchanged.
Corresponding LLVM change rL336613 already updated the
optimizations to not treat null pointer dereferencing
as undefined if the attribute is present.
Reviewers: t.p.northover, efriedma, jyknight, chandlerc, rnk, srhines, void, george.burgess.iv
Reviewed By: jyknight
Subscribers: drinkcat, xbolva00, cfe-commits
Differential Revision: https://reviews.llvm.org/D47894
llvm-svn: 337433
This patch uses CodeSegAttr to represent __declspec(code_seg) rather than
building on the existing support for #pragma code_seg.
The code_seg declspec is applied on functions and classes. This attribute
enables the placement of code into separate named segments, including compiler-
generated codes and template instantiations.
For more information, please see the following:
https://msdn.microsoft.com/en-us/library/dn636922.aspx
This patch fixes the regression for the support for attribute ((section).
746b78de78
Patch by Soumi Manna (Manna)
Differential Revision: https://reviews.llvm.org/D48841
llvm-svn: 337420
This change implements C++ DR1696, which makes initialization of a
reference member of a class from a temporary object ill-formed. The
standard wording here is imprecise, but we interpret it as meaning that
any time a mem-initializer would result in lifetime extension, the
program is ill-formed.
This reinstates r337226, reverted in r337255, with a fix for the
InitializedEntity alignment problem that was breaking ARM buildbots.
llvm-svn: 337329
This change breaks on ARM because pointers to clang::InitializedEntity are only
4 byte aligned and do not have 3 bits to store values. A possible solution
would be to change the fields in clang::InitializedEntity to enforce a bigger
alignment requirement.
The error message is
llvm/include/llvm/ADT/PointerIntPair.h:132:3: error: static_assert failed "PointerIntPair with integer size too large for pointer"
static_assert(IntBits <= PtrTraits::NumLowBitsAvailable,
include/llvm/ADT/PointerIntPair.h:73:13: note: in instantiation of template class 'llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> >' requested here
Value = Info::updateInt(Info::updatePointer(0, PtrVal),
llvm/include/llvm/ADT/PointerIntPair.h:51:5: note: in instantiation of member function 'llvm::PointerIntPair<const clang::InitializedEntity *, 3, (anonymous namespace)::LifetimeKind, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *>, llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> > >::setPointerAndInt' requested here
setPointerAndInt(PtrVal, IntVal);
^
llvm/tools/clang/lib/Sema/SemaInit.cpp:6237:12: note: in instantiation of member function 'llvm::PointerIntPair<const clang::InitializedEntity *, 3, (anonymous namespace)::LifetimeKind, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *>, llvm::PointerIntPairInfo<const clang::InitializedEntity *, 3, llvm::PointerLikeTypeTraits<const clang::InitializedEntity *> > >::PointerIntPair' requested here
return {Entity, LK_Extended};
Full log here:
http://lab.llvm.org:8011/builders/clang-cmake-armv7-global-isel/builds/1330http://lab.llvm.org:8011/builders/clang-cmake-armv7-full/builds/1394
llvm-svn: 337255
David Blaikie