Erich Keane [Wed, 1 Aug 2018 20:48:16 +0000 (20:48 +0000)]
[AST][1/4] Move the bit-fields from TagDecl, EnumDecl and RecordDecl into DeclContext
DeclContext has a little less than 8 bytes free due to the alignment
requirements on 64 bits archs. This set of patches moves the
bit-fields from classes deriving from DeclContext into DeclContext.
On 32 bits archs this increases the size of DeclContext by 4 bytes
but this is balanced by an equal or larger reduction in the size
of the classes deriving from it.
On 64 bits archs the size of DeclContext stays the same but
most of the classes deriving from it shrink by 8/16 bytes.
(-print-stats diff here https://reviews.llvm.org/D49728)
When doing an -fsyntax-only on all of Boost this result
in a 3.6% reduction in the size of all Decls and
a 1% reduction in the run time due to the lower cache
miss rate.
For now CXXRecordDecl is not touched but there is
an easy 6 (if I count correctly) bytes gain available there
by moving some bits from DefinitionData into the free
space of DeclContext. This will be the subject of another patch.
This patch sequence also enable the possibility of refactoring
FunctionDecl: To save space some bits from classes deriving from
FunctionDecl were moved to FunctionDecl. This resulted in a
lot of stuff in FunctionDecl which do not belong logically to it.
After this set of patches however it is just a simple matter of
adding a SomethingDeclBitfields in DeclContext and moving the
bits to it from FunctionDecl.
This first patch introduces the anonymous union in DeclContext
and all the *DeclBitfields classes holding the bit-fields, and moves
the bits from TagDecl, EnumDecl and RecordDecl into DeclContext.
This patch is followed by https://reviews.llvm.org/D49732,
https://reviews.llvm.org/D49733 and https://reviews.llvm.org/D49734.
Michal Gorny [Wed, 1 Aug 2018 20:38:22 +0000 (20:38 +0000)]
[test] Fix %hmaptool path for standalone builds
Fix %hmaptool path to refer to clang_tools_dir instead of
llvm_tools_dir, in order to fix standalone builds. The tool is built
as part of clang, so it won't be found in installed LLVM tools.
Hans Wennborg [Wed, 1 Aug 2018 17:51:23 +0000 (17:51 +0000)]
Revert r338455 "[constexpr] Support for constant evaluation of __builtin_memcpy and __builtin_memmove (in non-type-punning cases)."
It caused asserts during Chromium builds, see reply on the cfe-commits thread.
> This is intended to permit libc++ to make std::copy etc constexpr
> without sacrificing the optimization that uses memcpy on
> trivially-copyable types.
>
> __builtin_strcpy and __builtin_wcscpy are not handled by this change.
> They'd be straightforward to add, but we haven't encountered a need for
> them just yet.
Ilya Biryukov [Wed, 1 Aug 2018 15:32:56 +0000 (15:32 +0000)]
[Format] Fix for bug 35641
Summary:
Bug was caused due to comments at the start of scope. For a code like:
```
int func() { //
int b;
int c;
}
```
the comment at the first line gets IndentAndNestingLevel (1,1) whereas
the following declarations get only (0,1) which prevents them from insertion
of a new scope. So, I changed the AlignTokenSequence to look at previous
*non-comment* token when deciding whether to introduce a new scope into
stack or not.
David Green [Wed, 1 Aug 2018 14:36:12 +0000 (14:36 +0000)]
[UnrollAndJam] Add unroll_and_jam pragma handling
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.
Yuka Takahashi [Wed, 1 Aug 2018 09:50:02 +0000 (09:50 +0000)]
[Modules] Do not emit relocation error when -fno-validate-pch is set
Summary:
Clang emits error when implicit modules was relocated from the
first build directory. However this was biting our usecase where we copy
the contents of build directory to another directory in order to
distribute.
Roman Lebedev [Wed, 1 Aug 2018 06:06:16 +0000 (06:06 +0000)]
[AST] CastExpr: BasePathSize is not large enough.
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
Petr Hosek [Wed, 1 Aug 2018 03:30:06 +0000 (03:30 +0000)]
[OpenEmbedded] Explicitly specify -rtlib in tests
Tests added in r338294 implicitly assume that libgcc is the runtime library,
but that's not the case when the user configures Clang to use compiler-rt in
which case these tests will break. Explicitly request libgcc when invoking
clang in these tests to avoid that.
Artem Dergachev [Wed, 1 Aug 2018 01:58:15 +0000 (01:58 +0000)]
[analyzer] CallEvent: Add helper methods for obtaining the callee stack frame.
Newly added methods allow reasoning about the stack frame of the call (as
opposed to the stack frame on which the call was made, which was always
available) - obtain the stack frame context, obtain parameter regions - even if
the call is not going to be (or was not) inlined, i.e. even if the analysis
has never actually entered the stack frame.
Richard Smith [Wed, 1 Aug 2018 00:33:25 +0000 (00:33 +0000)]
[P0936R0] add [[clang::lifetimebound]] attribute
This patch adds support for a new attribute, [[clang::lifetimebound]], that
indicates that the lifetime of a function result is related to one of the
function arguments. When walking an initializer to make sure that the lifetime
of the initial value is at least as long as the lifetime of the initialized
object, we step through parameters (including the implicit object parameter of
a non-static member function) that are marked with this attribute.
There's nowhere to write an attribute on the implicit object parameter, so in
lieu of that, it may be applied to a function type (where it appears
immediately after the cv-qualifiers and ref-qualifier, which is as close to a
declaration of the implicit object parameter as we have). I'm currently
modeling this in the AST as the attribute appertaining to the function type.
Richard Smith [Tue, 31 Jul 2018 23:35:09 +0000 (23:35 +0000)]
[constexpr] Support for constant evaluation of __builtin_memcpy and
__builtin_memmove (in non-type-punning cases).
This is intended to permit libc++ to make std::copy etc constexpr
without sacrificing the optimization that uses memcpy on
trivially-copyable types.
__builtin_strcpy and __builtin_wcscpy are not handled by this change.
They'd be straightforward to add, but we haven't encountered a need for
them just yet.
Revert r337635 "[Driver] Sanitizer support based on runtime library presence"
This change causes issues with distributed build systems, which may only
have compiler binaries without any runtime libraries. See discussion
about this on https://reviews.llvm.org/D15225.
Richard Smith [Tue, 31 Jul 2018 21:01:53 +0000 (21:01 +0000)]
[serialization] PR34728: Don't assume that only a suffix of template
parameters can have default arguments.
At least for function templates and class template partial
specializations, it's possible for a template parameter with a default
argument to be followed by a non-pack template parameter with no default
argument, and this case was not properly handled here.
[CFG] [analyzer] Implement function argument construction contexts.
In r330377 and r338425 we have already identified what constitutes function
argument constructors and added stubs in order to prevent confusing them
with other temporary object constructors.
Now we implement a ConstructionContext sub-class to carry all the necessary
information about the construction site, namely call expression and argument
index.
On the analyzer side, the patch interacts with the recently implemented
pre-C++17 copy elision support in an interesting manner. If on the CFG side we
didn't find a construction context for the elidable constructor, we build
the CFG as if the elidable constructor is not elided, and the non-elided
constructor within it is a simple temporary. But the same problem may occur
in the analyzer: if the elidable constructor has a construction context but
the analyzer doesn't implement such context yet, the analyzer should also
try to skip copy elision and still inline the non-elided temporary constructor.
This was implemented by adding a "roll back" mechanism: when elision fails,
roll back the changes and proceed as if it's a simple temporary. The approach
is wonky, but i'm fine with that as long as it's merely a defensive mechanism
that should eventually go away once all construction contexts become supported.
[OpenCL] Forbid size dependent types used as kernel arguments
Summary:
Size_t, intptr_t, uintptr_t and ptrdiff_t cannot be used as kernel
arguments, according to OpenCL Specification s6.9k:
The size in bytes of these types are implementation-defined and in
addition can also be different for the OpenCL device and the host
processor making it difficult to allocate buffer objects to be passed
as arguments to a kernel declared as pointer to these types.
[CFG] [analyzer] Add stubs for constructor and message argument constructors.
CFG now correctly identifies construction context for temporaries constructed
for the purpose of passing into a function as an argument.
Such context is still not fully implemented because the information it provides
is not rich enough: it doens't contain information about argument index.
It will be addresssed later.
This patch is an extension of r330377 to C++ construct-expressions and
Objective-C message expressions which aren't call-expressions but require
similar handling. C++ new-expressions with placement arguments still remain to
be handled.
[analyzer] Don't try to simplify mixed Loc/NonLoc expressions.
This fix is similar to r337769 and addresses a regression caused by r337167.
When an operation between a nonloc::LocAsInteger and a non-pointer symbol
is performed, the LocAsInteger-specific part of information is lost.
When the non-pointer symbol is collapsing into a constant, we cannot easily
re-evaluate the result, because we need to recover the missing
LocAsInteger-specific information (eg., integer type, or the very fact that
this pointer was at some point converted to an integer).
Add one more defensive check to prevent crashes on trying to simplify a
SymSymExpr with different Loc-ness of operands.
[OPENMP] Change linkage of offloading symbols to support dropping
offload targets.
Changed the linkage of omp_offloading.img_start.<triple> and omp_offloading.img_end.<triple> symbols from external to external weak to allow dropping of some targets during linking.
[OPENMP] Prevent problems with linking of the static variables.
No need to change the linkage, we can avoid the problem using special variable. That points to the original variable and, thus, prevent some of the optimizations that might break the compilation.
David Bolvansky [Tue, 31 Jul 2018 14:21:46 +0000 (14:21 +0000)]
[RISCV] Add driver for riscv32-unknown-elf baremetal target
Summary:
This patch adds a driver for the baremetal RISC-V target (i.e. riscv32-unknown-elf). For reference, D39963 added basic target info and added support for riscv32-linux-unknown-elf.
Aleksandr Urakov [Tue, 31 Jul 2018 08:27:06 +0000 (08:27 +0000)]
Improve support of PDB as an external layout source
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.
Yes, i erroneously assumed that the "after" was meant,
but i was wrong:
> I really meant "performed before", for cases like 4u / -2,
> where -2 is implicitly converted to UINT_MAX - 2 before
> the computation. Conversions that are performed after
> a computation aren't part of the computation at all,
> so I think it's much clearer that they're not in scope
> for this sanitizer.
David Greene [Mon, 30 Jul 2018 19:08:20 +0000 (19:08 +0000)]
Make test/Driver/baremetal.cpp work with linkers other than lld
This test fails if clang is configure with, for example, gold as the
default linker. It does not appear that this test really relies on lld
so make the checks accept ld, ld.gold and ld.bfd too.
Roman Lebedev [Mon, 30 Jul 2018 18:58:30 +0000 (18:58 +0000)]
[clang][ubsan] Implicit Conversion Sanitizer - integer truncation - clang part
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.
[ARM, AArch64]: Use unadjusted alignment when passing composites as arguments
The "Procedure Call Procedure Call Standard for the ARM® Architecture"
(https://static.docs.arm.com/ihi0042/f/IHI0042F_aapcs.pdf), specifies that
composite types are passed according to their "natural alignment", i.e. the
alignment before alignment adjustment on the entire composite is applied.
The same applies for AArch64 ABI.
Clang, however, used the adjusted alignment.
GCC already implements the ABI correctly. With this patch Clang becomes
compatible with GCC and passes such arguments in accordance with AAPCS.
Reka Kovacs [Mon, 30 Jul 2018 15:43:45 +0000 (15:43 +0000)]
[analyzer] Add support for more invalidating functions in InnerPointerChecker.
According to the standard, pointers referring to the elements of a
`basic_string` may be invalidated if they are used as an argument to
any standard library function taking a reference to non-const
`basic_string` as an argument. This patch makes InnerPointerChecker warn
for these cases.
Adam Balogh [Mon, 30 Jul 2018 08:52:21 +0000 (08:52 +0000)]
[Analyzer] Iterator Checker Hotfix: Defer deletion of container data until its last iterator is cleaned up
The analyzer may consider a container region as dead while it still has live
iterators. We must defer deletion of the data belonging to such containers
until all its iterators are dead as well to be able to compare the iterator
to the begin and the end of the container which is stored in the container
data.
Revert r337456: [CodeGen] Disable aggressive structor optimizations at -O0, take 3
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.
[UBSan] Strengthen pointer checks in 'new' expressions
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:
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.
CUDA 8.0 E.3.9.4 says: Within the body of a __device__ or __global__
function, only __shared__ variables or variables without any device
memory qualifiers may be declared with static storage class.
It is unclear how a function-scope non-const static variable
without device memory qualifier is implemented, therefore only static
const variable without device memory qualifier is allowed, which
can be emitted as a global variable in constant address space.
Currently clang only allows function-scope static variable with
__shared__ qualifier.
This patch also allows function-scope static const variable without
device memory qualifier and emits it as a global variable in constant
address space.
Nicolas Lesser [Fri, 27 Jul 2018 21:55:12 +0000 (21:55 +0000)]
Parse a possible trailing postfix expression suffix after a fold expression
Summary:
This patch allows the parsing of a postfix expression involving a fold expression, which is legal as a fold-expression is a primary-expression.
Erik Pilkington [Fri, 27 Jul 2018 21:23:48 +0000 (21:23 +0000)]
[Sema] Use a TreeTransform to extract deduction guide parameter types
Previously, we just canonicalized the type, but this lead to crashes with
parameter types that referred to ParmVarDecls of the constructor. There may be
more cases that this TreeTransform needs to handle though, such as a constructor
parameter type referring to a member in an unevaluated context. Canonicalization
doesn't address these cases either though, so we can address them as-needed in
follow-up commits.
projects / clang / log