1265 Commits

Author SHA1 Message Date
Saurabh Jha
71ab6c98a0
[Matrix] Implement C-style explicit type conversions for matrix types.
This implements C-style type conversions for matrix types, as specified
in clang/docs/MatrixTypes.rst.

Fixes PR47141.

Reviewed By: fhahn

Differential Revision: https://reviews.llvm.org/D99037
2021-04-10 11:48:41 +01:00
Alex Richardson
dc4abca766 Handle alloc_size attribute on function pointers
I have been trying to statically find and analyze all calls to heap
allocation functions to determine how many of them use sizes known at
compile time vs only at runtime. While doing so I saw that quite a few
projects use replaceable function pointers for heap allocation and noticed
that clang was not able to annotate functions pointers with alloc_size.
I have changed the Sema checks to allow alloc_size on all function pointers
and typedefs for function pointers now and added checks that these
attributes are propagated to the LLVM IR correctly.

With this patch we can also compute __builtin_object_size() for calls to
allocation function pointers with the alloc_size attribute.

Reviewed By: aaron.ballman, erik.pilkington
Differential Revision: https://reviews.llvm.org/D55212
2021-04-09 18:49:38 +01:00
Hansang Bae
3da61ddae7 [OpenMP] Define omp_is_initial_device() variants in omp.h
omp_is_initial_device() is marked as a built-in function in the current
compiler, and user code guarded by this call may be optimized away,
resulting in undesired behavior in some cases. This patch provides a
possible fix for such cases by defining the routine as a variant
function and removing it from builtin list.

Differential Revision: https://reviews.llvm.org/D99447
2021-04-06 16:58:01 -05:00
Simon Pilgrim
2901dc7575 Don't directly dereference getAs<> casts to avoid potential null dereferences. NFCI.
Replace with castAs<> which asserts the cast is valid.

Fixes a number of static analyzer warnings.
2021-04-06 12:24:19 +01:00
Richard Smith
3315bd0beb PR49619: Remove delayed call to noteFailed.
This would assert if we hit the evaluation step limit between starting
to delay the call and finishing. In any case, delaying the call was
largely pointless as it doesn't really matter when we mark the
evaluation as having had side effects.
2021-03-17 17:25:18 -07:00
Richard Smith
a892b0015e PR49465: Disallow constant evaluation of a call to operator delete(nullptr).
The only time we would consider allowing this is inside a call to
std::allocator<T>::deallocate, whose contract does not permit deletion
of null pointers.
2021-03-09 15:06:06 -08:00
Richard Smith
bdf6fbc939 PR49239: Don't take shortcuts when constant evaluating in 'warn on UB'
mode.

We use that mode when evaluating ICEs in C, and those shortcuts could
result in ICE evaluation producing the wrong answer, specifically if we
evaluate a statement-expression as part of evaluating the ICE.
2021-02-18 18:31:08 -08:00
Hsiangkai Wang
766ee1096f [Clang][RISCV] Define RISC-V V builtin types
Add the types for the RISC-V V extension builtins.

These types will be used by the RISC-V V intrinsics which require
types of the form <vscale x 1 x i64>(LMUL=1 element size=64) or
<vscale x 4 x i32>(LMUL=2 element size=32), etc. The vector_size
attribute does not work for us as it doesn't create a scalable
vector type. We want these types to be opaque and have no operators
defined for them. We want them to be sizeless. This makes them
similar to the ARM SVE builtin types. But we will have quite a bit
more types. This patch adds around 60. Later patches will add
another 230 or so types representing tuples of these types similar
to the x2/x3/x4 types in ARM SVE. But with extra complexity that
these types are combined with the LMUL concept that is unique to
RISCV.

For more background see this RFC
http://lists.llvm.org/pipermail/llvm-dev/2020-October/145850.html

Authored-by: Roger Ferrer Ibanez <roger.ferrer@bsc.es>
Co-Authored-by: Hsiangkai Wang <kai.wang@sifive.com>

Differential Revision: https://reviews.llvm.org/D92715
2021-02-18 10:17:31 +08:00
Richard Smith
21e8bb8325 PR48606: The lifetime of a constexpr heap allocation always started
during the same evaluation.

It looks like the only case for which this matters is determining
whether mutable subobjects of a heap allocation can be modified during
constant evaluation.
2021-02-08 17:58:05 -08:00
Richard Smith
c945dc4a50 PR48587: is_constant_evaluated() should not evaluate to true during a
variable's destruction if it didn't do so during construction.

The standard doesn't give any guidance as to what to do here, but this
approach seems reasonable and conservative, and has been proposed to the
standard committee.
2021-02-08 17:34:40 -08:00
Zequan Wu
96fb49c3ff [AST] Update LVal before evaluating lambda decl fields.
Differential Revision: https://reviews.llvm.org/D96092
2021-02-04 17:01:09 -08:00
Tomas Matheson
01b9e613c2 [Clang][Codegen] Truncate initializers of union bitfield members
If an initial value is given for a bitfield that does not fit in the
bitfield, the value should be truncated. Constant folding for
expressions did not account for this truncation in the case of union
member functions, despite a warning being emitted. In some contexts,
evaluation of expressions was not enabled unless C++11, ROPI or RWPI
was enabled.

Differential Revision: https://reviews.llvm.org/D93101
2021-01-28 09:19:19 +00:00
Sven van Haastregt
79c727328b [clang] Fix signedness in vector bitcast evaluation
The included test case triggered a sign assertion on the result in
`Success()`.  This was caused by the APSInt created for a bitcast
having its signedness bit inverted.  The second APSInt constructor
argument is `isUnsigned`, so invert the result of
`isSignedIntegerType`.

Relanding this patch after reverting.  The test case had to be updated
to be insensitive to 32/64-bit extractelement indices.

Differential Revision: https://reviews.llvm.org/D95135
2021-01-27 09:30:26 +00:00
Sven van Haastregt
b16fb1ffc3 Revert "[clang] Fix signedness in vector bitcast evaluation"
This reverts commit 14947cd04701d923a57a0161fd1967b81e00ff5e because
it broke clang-cmake-armv7-quick.
2021-01-25 12:43:30 +00:00
Sven van Haastregt
14947cd047 [clang] Fix signedness in vector bitcast evaluation
The included test case triggered a sign assertion on the result in
`Success()`.  This was caused by the APSInt created for a bitcast
having its signedness bit inverted.  The second APSInt constructor
argument is `isUnsigned`, so invert the result of
`isSignedIntegerType`.

Differential Revision: https://reviews.llvm.org/D95135
2021-01-25 12:01:42 +00:00
George Burgess IV
b270fd59f0 Revert "[clang] Change builtin object size when subobject is invalid"
This reverts commit 275f30df8ad6de75e1f29e4b33eaeb67686caf0d.

As noted on the code review (https://reviews.llvm.org/D92892), this
change causes us to reject valid code in a few cases. Reverting so we
have more time to figure out what the right fix{es are, is} here.
2021-01-20 11:03:34 -08:00
Hans Wennborg
8ba442bc21 Revert "Following up on PR48517, fix handling of template arguments that refer"
Combined with 'da98651 - Revert "DR2064:
decltype(E) is only a dependent', this change (5a391d3) caused verifier
errors when building Chromium. See https://crbug.com/1168494#c1 for a
reproducer.

Additionally it reverts changes that were dependent on this one, see
below.

> Following up on PR48517, fix handling of template arguments that refer
> to dependent declarations.
>
> Treat an id-expression that names a local variable in a templated
> function as being instantiation-dependent.
>
> This addresses a language defect whereby a reference to a dependent
> declaration can be formed without any construct being value-dependent.
> Fixing that through value-dependence turns out to be problematic, so
> instead this patch takes the approach (proposed on the core reflector)
> of allowing the use of pointers or references to (but not values of)
> dependent declarations inside value-dependent expressions, and instead
> treating template arguments as dependent if they evaluate to a constant
> involving such dependent declarations.
>
> This ends up affecting a bunch of OpenMP tests, due to OpenMP
> imprecisely handling instantiation-dependent constructs, bailing out
> early instead of processing dependent constructs to the extent possible
> when handling the template.
>
> Previously committed as 8c1f2d15b826591cdf6bd6b468b8a7d23377b29e, and
> reverted because a dependency commit was reverted.

This reverts commit 5a391d38ac6c561ba908334d427f26124ed9132e.

It also restores clang/test/SemaCXX/coroutines.cpp to its state before
da986511fb9da1a46a0ca4dba2e49e2426036303.

Revert "[c++20] P1907R1: Support for generalized non-type template arguments of scalar type."

> Previously committed as 9e08e51a20d0d2b1c5724bb17e969d036fced4cd, and
> reverted because a dependency commit was reverted. This incorporates the
> following follow-on commits that were also reverted:
>
> 7e84aa1b81e72d44bcc58ffe1731bfc7abb73ce0 by Simon Pilgrim
> ed13d8c66781b50ff007cb089c5905f9bb9e8af2 by me
> 95c7b6cadbc9a3d4376ef44edbeb3c8bb5b8d7fc by Sam McCall
> 430d5d8429473c2b10b109991d7577a3cea41140 by Dave Zarzycki

This reverts commit 4b574008aef5a7235c1f894ab065fe300d26e786.

Revert "[msabi] Mangle a template argument referring to array-to-pointer decay"

> [msabi] Mangle a template argument referring to array-to-pointer decay
> applied to an array the same as the array itself.
>
> This follows MS ABI, and corrects a regression from the implementation
> of generalized non-type template parameters, where we "forgot" how to
> mangle this case.

This reverts commit 18e093faf726d15f210ab4917142beec51848258.
2021-01-20 15:55:35 +01:00
Richard Smith
5a391d38ac Following up on PR48517, fix handling of template arguments that refer
to dependent declarations.

Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.

This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.

This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.

Previously committed as 8c1f2d15b826591cdf6bd6b468b8a7d23377b29e, and
reverted because a dependency commit was reverted.
2021-01-18 21:05:01 -08:00
Jeffrey T Mott
275f30df8a [clang] Change builtin object size when subobject is invalid
Motivating example:

```
  struct { int v[10]; } t[10];

  __builtin_object_size(
      &t[0].v[11], // access past end of subobject
      1            // request remaining bytes of closest surrounding
                   // subobject
  );
```

In GCC, this returns 0. https://godbolt.org/z/7TeGs7

In current clang, however, this returns 356, the number of bytes
remaining in the whole variable, as if the `type` was 0 instead of 1.
https://godbolt.org/z/6Kffox

This patch checks for the specific case where we're requesting a
subobject's size (type 1) but the subobject is invalid.

Differential Revision: https://reviews.llvm.org/D92892
2021-01-07 12:34:07 -08:00
Arthur Eubanks
af0dbaaa38 Revert "Following up on PR48517, fix handling of template arguments that refer"
This reverts commit 8c1f2d15b826591cdf6bd6b468b8a7d23377b29e.

This is part of 5 commits being reverted due to https://crbug.com/1161059. See bug for repro.
2020-12-22 10:18:08 -08:00
Richard Smith
8c1f2d15b8 Following up on PR48517, fix handling of template arguments that refer
to dependent declarations.

Treat an id-expression that names a local variable in a templated
function as being instantiation-dependent.

This addresses a language defect whereby a reference to a dependent
declaration can be formed without any construct being value-dependent.
Fixing that through value-dependence turns out to be problematic, so
instead this patch takes the approach (proposed on the core reflector)
of allowing the use of pointers or references to (but not values of)
dependent declarations inside value-dependent expressions, and instead
treating template arguments as dependent if they evaluate to a constant
involving such dependent declarations.

This ends up affecting a bunch of OpenMP tests, due to OpenMP
imprecisely handling instantiation-dependent constructs, bailing out
early instead of processing dependent constructs to the extent possible
when handling the template.
2020-12-17 23:54:37 -08:00
Baptiste Saleil
57d83c3a90 [PowerPC] Enable paired vector type and intrinsics when MMA is disabled
This patch enables the Clang type __vector_pair and its associated LLVM
intrinsics even when MMA is disabled. With this patch, the type is now controlled
by the PPC paired-vector-memops option. The builtins and intrinsics will be
renamed to drop the mma prefix in another patch.

Differential Revision: https://reviews.llvm.org/D91819
2020-12-15 15:14:11 -06:00
Haojian Wu
a053929854 [AST] Fix a constexpr-evaluator crash on error-dependent returnstmt.
When the evaluator encounters an error-dependent returnstmt, before this patch
it returned a ESR_Returned without setting the result, the callsides think this
is a successful execution, and try to access the Result which causes the crash.

The fix is to always return failed as we don't know the result of the
error-dependent return stmt.

Differential Revision: https://reviews.llvm.org/D92969
2020-12-10 10:12:15 +01:00
Haojian Wu
bd4662cd3f [AST] Enhance the const expression evaluator to support error-dependent exprs.
Fix a crash when evaluating a constexpr function which contains
recovery-exprs. https://bugs.llvm.org/show_bug.cgi?id=46837

Would be nice to have constant expression evaluator support general template
value-dependent expressions, but it requires more work.

This patch is a good start I think, to handle the error-only
value-dependent expressions.

Differential Revision: https://reviews.llvm.org/D84637
2020-11-18 15:48:06 +01:00
Richard Smith
438a27f2e5 Move code to determine the type of an LValueBase out of ExprConstant and
into a member function on LValueBase. NFC.
2020-11-10 13:03:57 -08:00
Baptiste Saleil
40dd4d5233 [Clang][PowerPC] Add __vector_pair and __vector_quad types
Define the __vector_pair and __vector_quad types that are used to manipulate
the new accumulator registers introduced by MMA on PowerPC. Because these two
types are specific to PowerPC, they are defined in a separate new file so it
will be easier to add other PowerPC specific types if we need to in the future.

Differential Revision: https://reviews.llvm.org/D81508
2020-10-28 13:19:20 -05:00
Richard Smith
a5c7b46862 Fix checking for C++98 ICEs in C++11-and-later mode to not consider use
of a reference to be acceptable.
2020-10-26 16:59:48 -07:00
Zequan Wu
e56e7bd469 Revert "Revert "Ensure that checkInitIsICE is called exactly once for every variable""
This reverts commit a2ac64dd905422ed84e273a98d846df022a5e2ec.
2020-10-26 12:08:57 -07:00
Zequan Wu
a2ac64dd90 Revert "Ensure that checkInitIsICE is called exactly once for every variable"
This causing `Assertion Result && "Could not evaluate expression"' failed` at https://bugs.chromium.org/p/chromium/issues/detail?id=1142009

This reverts commit 76c0092665867a6defcd328ba0d0d976eb65d991.
2020-10-26 11:59:55 -07:00
Nico Weber
c686dfd617 Unconfuse gcc5.3 after 2e204e23911b1f / D87528
The local variable CmpResult added in that change shadowed the
type CmpResult, which confused an older gcc. Rename the variable
CmpResult to APFloatCmpResult.
2020-10-26 12:55:38 -04:00
Melanie Blower
2e204e2391 [clang] Enable support for #pragma STDC FENV_ACCESS
Reviewers: rjmccall, rsmith, sepavloff

Differential Revision: https://reviews.llvm.org/D87528
2020-10-25 06:46:25 -07:00
Richard Smith
7b3515880c For P0732R2, P1907R1: ensure that template parameter objects don't refer
to disallowed objects or have non-constant destruction.
2020-10-24 22:11:43 -07:00
Richard Smith
cb9b9842d3 PR47954 / DR2126: permit temporary objects that are lifetime-extended by
variables that are usable in constant expressions to themselves be
usable in constant expressions.
2020-10-23 14:29:18 -07:00
Richard Smith
2b7dfdd319 Fix typo in diagnostic name.
No functionality change intended.
2020-10-23 13:21:21 -07:00
Richard Smith
af189c8ab1 Fix constant evaluation of zero-initialization of a union whose first
FieldDecl is an unamed bitfield.

Unnamed bitfields aren't non-static data member, so such a bitfield
isn't actually the first non-static data member.
2020-10-22 17:03:59 -07:00
Richard Smith
8156074352 Ensure that the "value" of an unnamed bit-field isn't taken into
account when determining the identity of a class NTTP.
2020-10-21 18:51:55 -07:00
Richard Smith
0c417d4bef Add more test coverage for APValue serialization / deserialization and
fix a few exposed bugs.
2020-10-21 13:21:41 -07:00
Richard Smith
ba4768c966 [c++20] For P0732R2 / P1907R1: Basic frontend support for class types as
non-type template parameters.

Create a unique TemplateParamObjectDecl instance for each such value,
representing the globally unique template parameter object to which the
template parameter refers.

No IR generation support yet; that will follow in a separate patch.
2020-10-21 13:21:41 -07:00
Richard Smith
6781fee085 Don't permit array bound constant folding in OpenCL.
Permitting non-standards-driven "do the best you can" constant-folding
of array bounds is permitted solely as a GNU compatibility feature. We
should not be doing it in any language mode that is attempting to be
conforming.

From https://reviews.llvm.org/D20090 it appears the intent here was to
permit `__constant int` globals to be used in array bounds, but the
change in that patch only added half of the functionality necessary to
support that in the constant evaluator. This patch adds the other half
of the functionality and turns off constant folding for array bounds in
OpenCL.

I couldn't find any spec justification for accepting the kinds of cases
that D20090 accepts, so a reference to where in the OpenCL specification
this is permitted would be useful.

Note that this change also affects the code generation in one test:
because after 'const int n = 0' we now treat 'n' as a constant
expression with value 0, it's now a null pointer, so '(local int *)n'
forms a null pointer rather than a zero pointer.

Reviewed By: Anastasia

Differential Revision: https://reviews.llvm.org/D89520
2020-10-20 16:52:28 -07:00
Richard Smith
08c8d5bc51 Properly track whether a variable is constant-initialized.
This fixes miscomputation of __builtin_constant_evaluated in the
initializer of a variable that's not usable in constant expressions, but
is readable when constant-folding.

If evaluation of a constant initializer fails, we throw away the
evaluated result instead of keeping it as a non-constant-initializer
value for the variable, because it might not be a correct value.
To avoid regressions for initializers that are foldable but not formally
constant initializers, we now try constant-evaluating some globals in
C++ twice: once to check for a constant initializer (in an mode where
is_constannt_evaluated returns true) and again to determine the runtime
value if the initializer is not a constant initializer.
2020-10-19 23:59:11 -07:00
Richard Smith
3692d20d2b Refactor tracking of constant initializers for variables.
Instead of framing the interface around whether the variable is an ICE
(which is only interesting in C++98), primarily track whether the
initializer is a constant initializer (which is interesting in all C++
language modes).

No functionality change intended.
2020-10-19 21:31:19 -07:00
Richard Smith
76c0092665 Ensure that checkInitIsICE is called exactly once for every variable
for which it matters.

This is a step towards separating checking for a constant initializer
(in which std::is_constant_evaluated returns true) and any other
evaluation of a variable initializer (in which it returns false).
2020-10-19 19:04:04 -07:00
Richard Smith
7e801ca0ef Treat constant contexts as being in the default rounding mode.
This addresses a regression where pretty much all C++ compilations using
-frounding-math now fail, due to rounding being performed in constexpr
function definitions in the standard library.

This follows the "manifestly constant evaluated" approach described in
https://reviews.llvm.org/D87528#2270676 -- evaluations that are required
to succeed at compile time are permitted even in regions with dynamic
rounding modes, as are (unfortunately) the evaluation of the
initializers of local variables of const integral types.

Differential Revision: https://reviews.llvm.org/D89360
2020-10-16 13:26:15 -07:00
Mikael Holmen
e5e4653255 Remove dead variable to silence compiler warning [NFC] 2020-10-16 09:26:52 +02:00
Richard Smith
f7f2e4261a PR47805: Use a single object for a function parameter in the caller and
callee in constant evaluation.

We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.

This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
2020-10-14 17:43:51 -07:00
Richard Smith
69f7c006ff Revert "PR47805: Use a single object for a function parameter in the caller and"
Breaks a clangd unit test.

This reverts commit 8f8b9f2cca0b73314342c721186ae9c860ca273c.
2020-10-13 19:32:03 -07:00
Richard Smith
8f8b9f2cca PR47805: Use a single object for a function parameter in the caller and
callee in constant evaluation.

We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.

This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
2020-10-13 18:50:46 -07:00
Richard Smith
ab870f3030 Revert "PR47805: Use a single object for a function parameter in the caller and"
The buildbots are displeased.

This reverts commit 8d03a972ce8e92815ffe3d5d86aa027605ed92e2.
2020-10-13 15:59:00 -07:00
Richard Smith
8d03a972ce PR47805: Use a single object for a function parameter in the caller and
callee in constant evaluation.

We previously made a deep copy of function parameters of class type when
passing them, resulting in the destructor for the parameter applying to
the original argument value, ignoring any modifications made in the
function body. This also meant that the 'this' pointer of the function
parameter could be observed changing between the caller and the callee.

This change completely reimplements how we model function parameters
during constant evaluation. We now model them roughly as if they were
variables living in the caller, albeit with an artificially reduced
scope that covers only the duration of the function call, instead of
modeling them as temporaries in the caller that we partially "reparent"
into the callee at the point of the call. This brings some minor
diagnostic improvements, as well as significantly reduced stack usage
during constant evaluation.
2020-10-13 15:45:04 -07:00
Bevin Hansson
9fa7f48459 [Fixed Point] Add fixed-point to floating point cast types and consteval.
Reviewed By: leonardchan

Differential Revision: https://reviews.llvm.org/D86631
2020-10-13 13:26:56 +02:00