Commit Graph

3787 Commits

Author SHA1 Message Date
Richard Sandiford f09c7d642a [Sema][SVE] Add tests for valid and invalid type usage
This patch adds C and C++ tests for various uses of SVE types.
The tests cover valid uses that are already (correctly) accepted and
invalid uses that are already (correctly) rejected.  Later patches
will expand the tests as they fix other cases.[*]

Some of the tests for invalid uses aren't obviously related to
scalable vectors.  Part of the reason for having them is to make
sure that the quality of the error message doesn't regress once/if
the types are treated as incomplete types.

[*] These later patches all fix invalid uses that are being incorrectly
    accepted.  I don't know of any cases in which valid uses are being
    incorrectly rejected.  In other words, this series is all about
    diagnosing invalid code rather than enabling something new.

Differential Revision: https://reviews.llvm.org/D75571
2020-03-12 16:56:13 +00:00
Mikhail Maltsev 47edf5bafb [ARM,CDE] Generalize MVE intrinsics infrastructure to support CDE
Summary:
This patch generalizes the existing code to support CDE intrinsics
which will share some properties with existing MVE intrinsics
(some of the intrinsics will be polymorphic and accept/return values
of MVE vector types).
Specifically the patch:
* Adds new tablegen backends -gen-arm-cde-builtin-def,
  -gen-arm-cde-builtin-codegen, -gen-arm-cde-builtin-sema,
  -gen-arm-cde-builtin-aliases, -gen-arm-cde-builtin-header based on
  existing MVE backends.
* Renames the '__clang_arm_mve_alias' attribute into
  '__clang_arm_builtin_alias' (it will be used with CDE intrinsics as
  well as MVE intrinsics)
* Implements semantic checks for the coprocessor argument of the CDE
  intrinsics as well as the existing coprocessor intrinsics.
* Adds one CDE intrinsic __arm_cx1 to test the above changes

Reviewers: simon_tatham, MarkMurrayARM, ostannard, dmgreen

Reviewed By: simon_tatham

Subscribers: sdesmalen, mgorny, kristof.beyls, danielkiss, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D75850
2020-03-10 14:03:16 +00:00
Arthur Eubanks 51d7f64544 Don't emit pointer to int cast warnings under -Wmicrosoft-cast
Summary:
MSVC also warns on this:
$ cat /tmp/a.c
int f(void* p) { return (int) p; }

$ cl /c /tmp/a.c
C:/src/tmp/a.c(1): warning C4311: 'type cast': pointer truncation from
'void *' to 'int'

Warnings originally added in https://reviews.llvm.org/D72231.

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D75643
2020-03-09 13:27:46 -07:00
Erich Keane cc8390bfe3 Permit attribute 'used' with 'target' multiversioning.
This adds infrastructure for a multiversioning whitelist, plus adds
'used' to the allowed list with 'target'.  The behavior here mirrors the
implementation in GCC, where 'used' only applies to the single
declaration and doesn't apply to the ifunc or resolver.

This is not being applied to cpu_dispatch and cpu_specific, since the
rules are more complicated for cpu_specific, which emits multiple
symbols. Additionally, the author isn't currently aware of uses in the
wild of this combination, but is aware of a number of target+used
combinations.
2020-03-09 12:38:03 -07:00
Jeremy Stenglein 90e791d732 Add test missed in r843a9778fcd5
Differential Revision: https://reviews.llvm.org/D75768
2020-03-09 10:54:56 -07:00
Nathan Chancellor 2a41b31fcd [Sema] Add -Wpointer-to-enum-cast and -Wvoid-pointer-to-enum-cast
GCC does not warn on casts from pointers to enumerators, while clang
currently does: https://godbolt.org/z/3DFDVG

This causes a bunch of extra warnings in the Linux kernel, where
certain structs contain a void pointer to avoid using a gigantic
union for all of the various types of driver data, such as
versions.

Add a diagnostic that allows certain projects like the kernel to
disable the warning just for enums, which allows those projects to
keep full compatibility with GCC but keeps the intention of treating
casts to integers and enumerators the same by default so that other
projects have the opportunity to catch issues not noticed before (or
follow suite and disable the warning).

Link: https://github.com/ClangBuiltLinux/linux/issues/887

Reviewed By: rjmccall

Differential Revision: https://reviews.llvm.org/D75758
2020-03-07 16:43:39 -08:00
Aaron Puchert f23df1b2a3 Comment parsing: Treat \ref as inline command
Summary:
It's basically Doxygen's version of a link and can happen anywhere
inside of a paragraph. Fixes a bogus warning about empty paragraphs when
a parameter description starts with a link.

Reviewers: gribozavr2

Reviewed By: gribozavr2

Differential Revision: https://reviews.llvm.org/D75632
2020-03-05 19:44:34 +01:00
Erik Pilkington 29a4239d31 [Sema] Fix a crash when attaching comments to an implicit decl
When an implicitly generated decl was the first entry in the group, we
attempted to lookup comments with an empty FileID, leading to crashes. Avoid
this by trying to use the other declarations in the group, and then bailing out
if none are valid.

rdar://59919733
Differential revision: https://reviews.llvm.org/D75483
2020-03-02 16:49:53 -08:00
Luboš Luňák c61401b897 Revert "[clang] detect switch fallthrough marked by a comment (PR43465)"
This reverts commit 398b4ed87d.
As requested in https://bugs.llvm.org/show_bug.cgi?id=43465#c37 .
2020-03-02 22:33:25 +01:00
zoecarver 6201f6601d Check args passed to __builtin_frame_address and __builtin_return_address.
Verifies that an argument passed to __builtin_frame_address or __builtin_return_address is within the range [0, 0xFFFF]

Differential revision: https://reviews.llvm.org/D66839

Re-committed after fixed: c93112dc4f
2020-02-25 12:47:14 -08:00
Anastasia Stulova fa755d3e71 [Sema][C++] Propagate conversion kind to specialize the diagnostics
Compute and propagate conversion kind to diagnostics helper in C++
to provide more specific diagnostics about incorrect implicit
conversions in assignments, initializations, params, etc...

Duplicated some diagnostics as errors because C++ is more strict.

Tags: #clang

Differential Revision: https://reviews.llvm.org/D74116
2020-02-25 16:05:37 +00:00
Bill Wendling 50cac24877 Support output constraints on "asm goto"
Summary:
Clang's "asm goto" feature didn't initially support outputs constraints. That
was the same behavior as gcc's implementation. The decision by gcc not to
support outputs was based on a restriction in their IR regarding terminators.
LLVM doesn't restrict terminators from returning values (e.g. 'invoke'), so
it made sense to support this feature.

Output values are valid only on the 'fallthrough' path. If an output value's used
on an indirect branch, then it's 'poisoned'.

In theory, outputs *could* be valid on the 'indirect' paths, but it's very
difficult to guarantee that the original semantics would be retained. E.g.
because indirect labels could be used as data, we wouldn't be able to split
critical edges in situations where two 'callbr' instructions have the same
indirect label, because the indirect branch's destination would no longer be
the same.

Reviewers: jyknight, nickdesaulniers, hfinkel

Reviewed By: jyknight, nickdesaulniers

Subscribers: MaskRay, rsmith, hiraditya, llvm-commits, cfe-commits, craig.topper, rnk

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D69876
2020-02-24 18:51:29 -08:00
zoecarver 6980782572 Revert "Validate argument passed to __builtin_frame_address and __builtin_return_address"
This reverts commit c93112dc4f.
2020-02-24 14:35:02 -08:00
zoecarver c93112dc4f Validate argument passed to __builtin_frame_address and __builtin_return_address
Verifies that the argument passed to __builtin_frame_address and __builtin_return_address is within the range [0, 0xFFFF].
2020-02-24 14:23:41 -08:00
Mark de Wever 56eb15a1c7 [Sema] Fix pointer-to-int-cast diagnostic for _Bool
The diagnostic added in D72231 also shows a diagnostic when casting to a
_Bool. This is unwanted. This patch removes the diagnostic for _Bool types.

Differential Revision: https://reviews.llvm.org/D74860
2020-02-22 19:39:49 +01:00
Jan Korous 2f56789c8f [clang][doxygen] Fix false -Wdocumentation warning for tag typedefs
For tag typedefs like this one:

/*!
@class Foo
*/
typedef class { } Foo;

clang -Wdocumentation gives:

warning: '@class' command should not be used in a comment attached to a
non-struct declaration [-Wdocumentation]

... while doxygen seems fine with it.

Differential Revision: https://reviews.llvm.org/D74746
2020-02-20 11:32:30 -08:00
Roman Lebedev 9ea5d17cc9
[Sema] Demote call-site-based 'alignment is a power of two' check for AllocAlignAttr into a warning
Summary:
As @rsmith notes in https://reviews.llvm.org/D73020#inline-672219
while that is certainly UB land, it may not be actually reachable at runtime, e.g.:
```
template<int N> void *make() {
  if ((N & (N-1)) == 0)
    return operator new(N, std::align_val_t(N));
  else
    return operator new(N);
}
void *p = make<7>();
```
and we shouldn't really error-out there.

That being said, i'm not really following the logic here.
Which ones of these cases should remain being an error?

Reviewers: rsmith, erichkeane

Reviewed By: erichkeane

Subscribers: cfe-commits, rsmith

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73996
2020-02-20 16:39:26 +03:00
John Marshall 260b91f379 Use getLocation() in "too few/too many arguments" diagnostic
Use the more accurate location when emitting the location of the
function being called's prototype in diagnostics emitted when calling
a function with an incorrect number of arguments.

In particular, avoids showing a trace of irrelevant macro expansions
for "MY_EXPORT static int AwesomeFunction(int, int);". Fixes PR#23564.
2020-02-18 11:23:17 -05:00
Mark de Wever af20211944 [Sema] Fix pointer-to-int-cast for MSVC build bot
Revision 9658d895c8 breaks the clang-x64-windows-msvc build bot [1].
This should fix the unit test using the same method as used in 9658d895c8.

Note I don't have access to a Windows system so the patch is based on the
errors generated by the bot.

[1] http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/14358

Differential Revision: https://reviews.llvm.org/D74694
2020-02-16 19:09:59 +01:00
Mark de Wever 9658d895c8 [Sema] Adds the pointer-to-int-cast diagnostic
Converting a pointer to an integer whose result cannot represented in the
integer type is undefined behavior is C and prohibited in C++. C++ already
has a diagnostic when casting. This adds a diagnostic for C.

Since this diagnostic uses the range of the conversion it also modifies
int-to-pointer-cast diagnostic to use a range.

Fixes PR8718: No warning on casting between pointer and non-pointer-sized int

Differential Revision: https://reviews.llvm.org/D72231
2020-02-16 15:38:25 +01:00
Aaron Puchert 705306526b Fix tests after previous commit
We don't want to test for this warning, so we just fix it.
2020-02-14 19:41:01 +01:00
Aaron Puchert 2f26bc5542 Warn about zero-parameter K&R definitions in -Wstrict-prototypes
Summary:
Zero-parameter K&R definitions specify that the function has no
parameters, but they are still not prototypes, so calling the function
with the wrong number of parameters is just a warning, not an error.

The C11 standard doesn't seem to directly define what a prototype is,
but it can be inferred from 6.9.1p7: "If the declarator includes a
parameter type list, the list also specifies the types of all the
parameters; such a declarator also serves as a function prototype
for later calls to the same function in the same translation unit."
This refers to 6.7.6.3p5: "If, in the declaration “T D1”, D1 has
the form
    D(parameter-type-list)
or
    D(identifier-list_opt)
[...]". Later in 6.11.7 it also refers only to the parameter-type-list
variant as prototype: "The use of function definitions with separate
parameter identifier and declaration lists (not prototype-format
parameter type and identifier declarators) is an obsolescent feature."

We already correctly treat an empty parameter list as non-prototype
declaration, so we can just take that information.

GCC also warns about this with -Wstrict-prototypes.

This shouldn't affect C++, because there all FunctionType's are
FunctionProtoTypes. I added a simple test for that.

Reviewed By: aaron.ballman

Differential Revision: https://reviews.llvm.org/D66919
2020-02-14 19:25:02 +01:00
Guillaume Chatelet d65bbf81f8 [clang] Add support for __builtin_memcpy_inline
Summary: This is a follow up on D61634 and the last step to implement http://lists.llvm.org/pipermail/llvm-dev/2019-April/131973.html

Reviewers: efriedma, courbet, tejohnson

Subscribers: hiraditya, cfe-commits, llvm-commits, jdoerfert, t.p.northover

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73543
2020-02-07 23:55:26 +01:00
Douglas Yung 02fffbb5fa Fix test after test changes added in da3dc00 caused the test to break
on platforms that default to an older C standard (like the PS4).

This should fix the test failure on the PS4 bots.
2020-02-06 18:19:01 -08:00
Richard Smith da3dc0011e PR44684: Look through parens and similar constructs when determining
whether a call is to a builtin.

We already had a general mechanism to do this but for some reason
weren't using it. In passing, check for the other unary operators that
can intervene in a reasonably-direct function call (we already handled
'&' but missed '*' and '+').

This reverts commit aaae6b1b61,
reinstating af80b8ccc5, with a fix to
clang-tidy.
2020-02-06 12:21:54 -08:00
Mikhail Maltsev 2694cc3dca [ARM][MVE] Add fixed point vector conversion intrinsics
Summary:
This patch implements the following Arm ACLE MVE intrinsics:
* vcvtq_n_*
* vcvtq_m_n_*
* vcvtq_x_n_*

and two corresponding LLVM IR intrinsics:
* int_arm_mve_vcvt_fix (vcvtq_n_*)
* int_arm_mve_vcvt_fix_predicated (vcvtq_m_n_*, vcvtq_x_n_*)

Reviewers: simon_tatham, ostannard, MarkMurrayARM, dmgreen

Reviewed By: MarkMurrayARM

Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D74134
2020-02-06 16:49:45 +00:00
Luboš Luňák 398b4ed87d [clang] detect switch fallthrough marked by a comment (PR43465)
The regex can be extended if needed, but this should probably handle
most of the cases.

Differential Revision: https://reviews.llvm.org/D73852
2020-02-03 19:33:05 +01:00
Simon Tatham f8d4afc49a [ARM,MVE] Add intrinsics for v[id]dupq and v[id]wdupq.
Summary:
These instructions generate a vector of consecutive elements starting
from a given base value and incrementing by 1, 2, 4 or 8. The `wdup`
versions also wrap the values back to zero when they reach a given
limit value. The instruction updates the scalar base register so that
another use of the same instruction will continue the sequence from
where the previous one left off.

At the IR level, I've represented these instructions as a family of
target-specific intrinsics with two return values (the constructed
vector and the updated base). The user-facing ACLE API provides a set
of intrinsics that throw away the written-back base and another set
that receive it as a pointer so they can update it, plus the usual
predicated versions.

Because the intrinsics return two values (as do the underlying
instructions), the isel has to be done in C++.

This is the first family of MVE intrinsics that use the `imm_1248`
immediate type in the clang Tablegen framework, so naturally, I found
I'd given it the wrong C integer type. Also added some tests of the
check that the immediate has a legal value, because this is the first
time those particular checks have been exercised.

Finally, I also had to fix a bug in MveEmitter which failed an
assertion when I nested two `seq` nodes (the inner one used to extract
the two values from the pair returned by the IR intrinsic, and the
outer one put on by the predication multiclass).

Reviewers: dmgreen, MarkMurrayARM, miyuki, ostannard

Reviewed By: dmgreen

Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D73357
2020-02-03 11:20:06 +00:00
Nico Weber e916c8dfe4 Revert "[Clang] Warn about 'z' printf modifier in old MSVC."
This reverts commit fe0d1b6a8a.
Makes Analysis/taint-generic.c fail on some Windows systems.
2020-01-28 09:27:54 -05:00
Nico Weber aaae6b1b61 Revert "PR44684: Look through parens and similar constructs when determining"
This reverts commit af80b8ccc5.
It broke clang-tidy/checkers/modernize-use-uncaught-exceptions.cpp in
check-clang-tools on macOS and Windows, see e.g.
http://lab.llvm.org:8011/builders/clang-x64-windows-msvc/builds/13976/steps/stage%201%20check/logs/stdio
2020-01-28 09:03:27 -05:00
Simon Tatham fe0d1b6a8a [Clang] Warn about 'z' printf modifier in old MSVC.
Summary:
The 'z' length modifier, signalling that an integer format specifier
takes a `size_t` sized integer, is only supported by the C library of
MSVC 2015 and later. Earlier versions don't recognize the 'z' at all,
and respond to `printf("%zu", x)` by just printing "zu".

So, if the MS compatibility version is set to a value earlier than
MSVC2015, it's useful to warn about 'z' modifiers in printf format
strings we check.

Reviewers: aaron.ballman, lebedev.ri, rnk, majnemer, zturner

Reviewed By: aaron.ballman

Subscribers: amccarth, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D73457
2020-01-28 09:04:45 +00:00
Richard Smith af80b8ccc5 PR44684: Look through parens and similar constructs when determining
whether a call is to a builtin.

We already had a general mechanism to do this but for some reason
weren't using it. In passing, check for the other unary operators that
can intervene in a reasonably-direct function call (we already handled
'&' but missed '*' and '+').
2020-01-27 18:20:57 -08:00
serge-sans-paille 6d485ff455 Improve static checks for sprintf and __builtin___sprintf_chk
Implement a pessimistic evaluator of the minimal required size for a buffer
based on the format string, and couple that with the fortified version to emit a
warning when the buffer size is lower than the lower bound computed from the
format string.

Differential Revision: https://reviews.llvm.org/D71566
2020-01-25 18:10:34 +01:00
Roman Lebedev 1d0972ff5e
[Sema] Introduce MaximumAlignment value, to be used instead of magical constants
There is llvm::Value::MaximumAlignment, which is numerically
equivalent to these constants, but we can't use it directly
because we can't include llvm IR headers in clang Sema.
So instead, copy-paste the constant, and fixup the places to use it.

This was initially reviewed in https://reviews.llvm.org/D72998
2020-01-24 17:49:17 +03:00
Roman Lebedev 0a002f679b
[Sema] Try 2: Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`
Summary:
For `__builtin_assume_aligned()`, we do validate that the alignment
is not greater than `536870912` (D68824), but we don't do that for
`__attribute__((assume_aligned(N)))` attribute.
I suspect we should.

This was initially committed in a4cfb15d15
but reverted in 210f0882c9 due to
suspicious bot failures.

Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert

Reviewed By: erichkeane

Subscribers: cfe-commits, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D72994
2020-01-24 16:56:39 +03:00
Roman Lebedev ba545c814b
[Sema] Try 2: Attempt to perform call-size-specific `__attribute__((alloc_align(param_idx)))` validation
Summary:
`alloc_align` attribute takes parameter number, not the alignment itself,
so given **just** the attribute/function declaration we can't do any
sanity checking for said alignment.

However, at call site, given the actual `Expr` that is passed
into that parameter, we //might// be able to evaluate said `Expr`
as Integer Constant Expression, and perform the sanity checks.
But since there is no requirement for that argument to be an immediate,
we may fail, and that's okay.

However if we did evaluate, we should enforce the same constraints
as with `__builtin_assume_aligned()`/`__attribute__((assume_aligned(imm)))`:
said alignment is a power of two, and is not greater than our magic threshold


This was initially committed in c2a9061ac5
but reverted in 00756b1823 because of
suspicious bot failures.

Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert

Reviewed By: erichkeane

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72996
2020-01-24 14:42:45 +03:00
Fangrui Song 69bf40c45f [Driver][CodeGen] Support -fpatchable-function-entry=N,M and __attribute__((patchable_function_entry(N,M))) where M>0
Reviewed By: nickdesaulniers

Differential Revision: https://reviews.llvm.org/D73072
2020-01-23 17:02:54 -08:00
Roman Lebedev 210f0882c9
Revert "[Sema] Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`"
Likely makes bots angry.

This reverts commit a4cfb15d15.

# Conflicts:
#	clang/lib/Sema/SemaDeclAttr.cpp
2020-01-23 23:10:35 +03:00
Roman Lebedev 00756b1823
Revert "[Sema] Attempt to perform call-size-specific `__attribute__((alloc_align(param_idx)))` validation"
Likely makes bots angry.

This reverts commit c2a9061ac5.
2020-01-23 23:10:34 +03:00
Roman Lebedev c2a9061ac5
[Sema] Attempt to perform call-size-specific `__attribute__((alloc_align(param_idx)))` validation
Summary:
`alloc_align` attribute takes parameter number, not the alignment itself,
so given **just** the attribute/function declaration we can't do any
sanity checking for said alignment.

However, at call site, given the actual `Expr` that is passed
into that parameter, we //might// be able to evaluate said `Expr`
as Integer Constant Expression, and perform the sanity checks.
But since there is no requirement for that argument to be an immediate,
we may fail, and that's okay.

However if we did evaluate, we should enforce the same constraints
as with `__builtin_assume_aligned()`/`__attribute__((assume_aligned(imm)))`:
said alignment is a power of two, and is not greater than our magic threshold

Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert

Reviewed By: erichkeane

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72996
2020-01-23 22:50:49 +03:00
Roman Lebedev a4cfb15d15
[Sema] Sanity-check alignment requested via `__attribute__((assume_aligned(imm)))`
Summary:
For `__builtin_assume_aligned()`, we do validate that the alignment
is not greater than `536870912` (D68824), but we don't do that for
`__attribute__((assume_aligned(N)))` attribute.
I suspect we should.

Reviewers: erichkeane, aaron.ballman, hfinkel, rsmith, jdoerfert

Reviewed By: erichkeane

Subscribers: cfe-commits, llvm-commits

Tags: #llvm, #clang

Differential Revision: https://reviews.llvm.org/D72994
2020-01-23 22:50:48 +03:00
Simon Tatham 4321c6af28 [ARM,MVE] Support immediate vbicq,vorrq,vmvnq intrinsics.
Summary:
Immediate vmvnq is code-generated as a simple vector constant in IR,
and left to the backend to recognize that it can be created with an
MVE VMVN instruction. The predicated version is represented as a
select between the input and the same constant, and I've added a
Tablegen isel rule to turn that into a predicated VMVN. (That should
be better than the previous VMVN + VPSEL: it's the same number of
instructions but now it can fold into an adjacent VPT block.)

The unpredicated forms of VBIC and VORR are done by enabling the same
isel lowering as for NEON, recognizing appropriate immediates and
rewriting them as ARMISD::VBICIMM / ARMISD::VORRIMM SDNodes, which I
then instruction-select into the right MVE instructions (now that I've
also reworked those instructions to use the same MC operand encoding).
In order to do that, I had to promote the Tablegen SDNode instance
`NEONvorrImm` to a general `ARMvorrImm` available in MVE as well, and
similarly for `NEONvbicImm`.

The predicated forms of VBIC and VORR are represented as a vector
select between the original input vector and the output of the
unpredicated operation. The main convenience of this is that it still
lets me use the existing isel lowering for VBICIMM/VORRIMM, and not
have to write another copy of the operand encoding translation code.

This intrinsic family is the first to use the `imm_simd` system I put
into the MveEmitter tablegen backend. So, naturally, it showed up a
bug or two (emitting bogus range checks and the like). Fixed those,
and added a full set of tests for the permissible immediates in the
existing Sema test.

Also adjusted the isel pattern for `vmovlb.u8`, which stopped matching
because lowering started turning its input into a VBICIMM. Now it
recognizes the VBICIMM instead.

Reviewers: dmgreen, MarkMurrayARM, miyuki, ostannard

Reviewed By: dmgreen

Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D72934
2020-01-23 11:53:52 +00:00
Aaron Ballman a8c2f76cd2 Removing an accidentally duplicated line of test code to fix bots. 2020-01-21 16:03:22 -05:00
Etienne Pierre-Doray 5260bc2497 Allow arbitrary capability name in Thread Safety Analysis
Restricting the names of capabilities to only "role" or "mutex" makes
for awkward diagnostic text, such as with:
https://chromium-review.googlesource.com/c/chromium/src/+/1948098/19/base/sequence_checker_unittest.nc#33
2020-01-21 15:43:17 -05:00
Mitch Phillips edd4398f4c Revert "PR17164: Change clang's default behavior from -flax-vector-conversions=all to -flax-vector-conversions=integer."
This patch broke the Sanitizer buildbots. Please see the commit's
differential revision for more information
(https://reviews.llvm.org/D67678).

This reverts commit b72a8c65e4.
2020-01-20 16:34:09 -08:00
Krzysztof Parzyszek 6f3effbbf0 [Hexagon] Update autogenerated intrinsic info in clang
In addition to that, use target features to validate intrinsic
availability on a given target.
2020-01-16 14:20:12 -06:00
Richard Smith b72a8c65e4 PR17164: Change clang's default behavior from -flax-vector-conversions=all to -flax-vector-conversions=integer.
Summary:
See proposal on cfe-dev:
http://lists.llvm.org/pipermail/cfe-dev/2019-April/062030.html

Reviewers: SjoerdMeijer, eli.friedman

Subscribers: kristof.beyls, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67678
2020-01-15 13:14:57 -08:00
Simon Tatham ada01d1b86 [clang] New __attribute__((__clang_arm_mve_strict_polymorphism)).
This is applied to the vector types defined in <arm_mve.h> for use
with the intrinsics for the ARM MVE vector architecture.

Its purpose is to inhibit lax vector conversions, but only in the
context of overload resolution of the MVE polymorphic intrinsic
functions. This solves an ambiguity problem with polymorphic MVE
intrinsics that take a vector and a scalar argument: the scalar
argument can often have the wrong integer type due to default integer
promotions or unsuffixed literals, and therefore, the type of the
vector argument should be considered trustworthy when resolving MVE
polymorphism.

As part of the same change, I've added the new attribute to the
declarations generated by the MveEmitter Tablegen backend (and
corrected a namespace issue with the other attribute while I was
there).

Reviewers: aaron.ballman, dmgreen

Reviewed By: aaron.ballman

Subscribers: kristof.beyls, JDevlieghere, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D72518
2020-01-15 15:04:10 +00:00
Erich Keane 349636d2bf Implement VectorType conditional operator GNU extension.
GCC supports the conditional operator on VectorTypes that acts as a
'select' in C++ mode. This patch implements the support. Types are
converted as closely to GCC's behavior as possible, though in a few
places consistency with our existing vector type support was preferred.

Note that this implementation is different from the OpenCL version in a
number of ways, so it unfortunately required a different implementation.

First, the SEMA rules and promotion rules are significantly different.

Secondly, GCC implements COND[i] != 0 ? LHS[i] : RHS[i] (where i is in
the range 0- VectorSize, for each element).  In OpenCL, the condition is
COND[i] < 0 ? LHS[i]: RHS[i].

In the process of implementing this, it was also required to make the
expression COND ? LHS : RHS type dependent if COND is type dependent,
since the type is now dependent on the condition.  For example:

    T ? 1 : 2;

Is not typically type dependent, since the result can be deduced from
the operands.  HOWEVER, if T is a VectorType now, it could change this
to a 'select' (basically a swizzle with a non-constant mask) with the 1
and 2 being promoted to vectors themselves.

While this is a change, it is NOT a standards incompatible change. Based
on my (and D. Gregor's, at the time of writing the code) reading of the
standard, the expression is supposed to be type dependent if ANY
sub-expression is type dependent.

Differential Revision: https://reviews.llvm.org/D71463
2020-01-13 13:27:20 -08:00
Fangrui Song a44c434b68 Support function attribute patchable_function_entry
This feature is generic. Make it applicable for AArch64 and X86 because
the backend has only implemented NOP insertion for AArch64 and X86.

Reviewed By: nickdesaulniers, aaron.ballman

Differential Revision: https://reviews.llvm.org/D72221
2020-01-10 09:57:34 -08:00
Andrew Paverd bdd88b7ed3 Add support for __declspec(guard(nocf))
Summary:
Avoid using the `nocf_check` attribute with Control Flow Guard. Instead, use a
new `"guard_nocf"` function attribute to indicate that checks should not be
added on indirect calls within that function. Add support for
`__declspec(guard(nocf))` following the same syntax as MSVC.

Reviewers: rnk, dmajor, pcc, hans, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: aaron.ballman, tomrittervg, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D72167
2020-01-10 16:04:12 +00:00
Alex Richardson 8c387cbea7 Add builtins for aligning and checking alignment of pointers and integers
This change introduces three new builtins (which work on both pointers
and integers) that can be used instead of common bitwise arithmetic:
__builtin_align_up(x, alignment), __builtin_align_down(x, alignment) and
__builtin_is_aligned(x, alignment).

I originally added these builtins to the CHERI fork of LLVM a few years ago
to handle the slightly different C semantics that we use for CHERI [1].
Until recently these builtins (or sequences of other builtins) were
required to generate correct code. I have since made changes to the default
C semantics so that they are no longer strictly necessary (but using them
does generate slightly more efficient code). However, based on our experience
using them in various projects over the past few years, I believe that adding
these builtins to clang would be useful.

These builtins have the following benefit over bit-manipulation and casts
via uintptr_t:

- The named builtins clearly convey the semantics of the operation. While
  checking alignment using __builtin_is_aligned(x, 16) versus
  ((x & 15) == 0) is probably not a huge win in readably, I personally find
  __builtin_align_up(x, N) a lot easier to read than (x+(N-1))&~(N-1).
- They preserve the type of the argument (including const qualifiers). When
  using casts via uintptr_t, it is easy to cast to the wrong type or strip
  qualifiers such as const.
- If the alignment argument is a constant value, clang can check that it is
  a power-of-two and within the range of the type. Since the semantics of
  these builtins is well defined compared to arbitrary bit-manipulation,
  it is possible to add a UBSAN checker that the run-time value is a valid
  power-of-two. I intend to add this as a follow-up to this change.
- The builtins avoids int-to-pointer casts both in C and LLVM IR.
  In the future (i.e. once most optimizations handle it), we could use the new
  llvm.ptrmask intrinsic to avoid the ptrtoint instruction that would normally
  be generated.
- They can be used to round up/down to the next aligned value for both
  integers and pointers without requiring two separate macros.
- In many projects the alignment operations are already wrapped in macros (e.g.
  roundup2 and rounddown2 in FreeBSD), so by replacing the macro implementation
  with a builtin call, we get improved diagnostics for many call-sites while
  only having to change a few lines.
- Finally, the builtins also emit assume_aligned metadata when used on pointers.
  This can improve code generation compared to the uintptr_t casts.

[1] In our CHERI compiler we have compilation mode where all pointers are
implemented as capabilities (essentially unforgeable 128-bit fat pointers).
In our original model, casts from uintptr_t (which is a 128-bit capability)
to an integer value returned the "offset" of the capability (i.e. the
difference between the virtual address and the base of the allocation).
This causes problems for cases such as checking the alignment: for example, the
expression `if ((uintptr_t)ptr & 63) == 0` is generally used to check if the
pointer is aligned to a multiple of 64 bytes. The problem with offsets is that
any pointer to the beginning of an allocation will have an offset of zero, so
this check always succeeds in that case (even if the address is not correctly
aligned). The same issues also exist when aligning up or down. Using the
alignment builtins ensures that the address is used instead of the offset. While
I have since changed the default C semantics to return the address instead of
the offset when casting, this offset compilation mode can still be used by
passing a command-line flag.

Reviewers: rsmith, aaron.ballman, theraven, fhahn, lebedev.ri, nlopes, aqjune
Reviewed By: aaron.ballman, lebedev.ri
Differential Revision: https://reviews.llvm.org/D71499
2020-01-09 21:48:29 +00:00
Simon Tatham d857e114b5 [ARM,MVE] Fix valid immediate range for vsliq_n.
In common with most MVE immediate shift instructions, the left shift
takes an immediate in the range [0,n-1], while the right shift takes
one in the range [1,n]. I had absent-mindedly made them both the
latter.

While I'm here, I've added a set of regression tests checking both
ends of the immediate range for a representative sample of the
immediate shifts.
2020-01-09 15:04:47 +00:00
Simon Tatham 4978296cd8 [ARM,MVE] Support -ve offsets in gather-load intrinsics.
Summary:
The ACLE intrinsics with `gather_base` or `scatter_base` in the name
are wrappers on the MVE load/store instructions that take a vector of
base addresses and an immediate offset. The immediate offset can be up
to 127 times the alignment unit, and it can be positive or negative.

At the MC layer, we got that right. But in the Sema error checking for
the wrapping intrinsics, the offset was erroneously constrained to be
positive.

To fix this I've adjusted the `imm_mem7bit` class in the Tablegen that
defines the intrinsics. But that causes integer literals like
`0xfffffffffffffe04` to appear in the autogenerated calls to
`SemaBuiltinConstantArgRange`, which provokes a compiler warning
because that's out of the non-overflowing range of an `int64_t`. So
I've also tweaked `MveEmitter` to emit that as `-0x1fc` instead.

Updated the tests of the Sema checks themselves, and also adjusted a
random sample of the CodeGen tests to actually use negative offsets
and prove they get all the way through code generation without causing
a crash.

Reviewers: dmgreen, miyuki, MarkMurrayARM

Reviewed By: dmgreen

Subscribers: kristof.beyls, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D72268
2020-01-06 16:33:07 +00:00
Bruno Ricci 8a571538df
[Sema] SequenceChecker: Fix handling of operator ||, && and ?:
The current handling of the operators ||, && and ?: has a number of false
positive and false negative. The issues for operator || and && are:

1. We need to add sequencing regions for the LHS and RHS as is done for the
   comma operator. Not doing so causes false positives in expressions like
   `((a++, false) || (a++, false))` (from PR39779, see PR22197 for another
    example).

2. In the current implementation when the evaluation of the LHS fails, the RHS
   is added to a worklist to be processed later. This results in false negatives
   in expressions like `(a && a++) + a`.

Fix these issues by introducing sequencing regions for the LHS and RHS, and by
not deferring the visitation of the RHS.

The issues with the ternary operator ?: are similar, with the added twist that
we should not warn on expressions like `(x ? y += 1 : y += 2)` since exactly
one of the 2nd and 3rd expression is going to be evaluated, but we should still
warn on expressions like `(x ? y += 1 : y += 2) = y`.

Differential Revision: https://reviews.llvm.org/D57747

Reviewed By: rsmith
2019-12-22 12:27:31 +00:00
Mark de Wever be1a9b3863 [Wdocumentation] Implement \anchor
Differential revision: https://reviews.llvm.org/D69223
2019-12-21 14:52:21 +01:00
Gabor Horvath fe17b30a79 [attributes][analyzer] Add annotations for handles.
These annotations will be used in an upcomming static analyzer check
that finds handle leaks, use after releases, and double releases.

Differential Revision: https://reviews.llvm.org/D70469
2019-12-20 11:47:55 -08:00
Amy Huang a85f5efd95 Add support for the MS qualifiers __ptr32, __ptr64, __sptr, __uptr.
Summary:
This adds parsing of the qualifiers __ptr32, __ptr64, __sptr, and __uptr and
lowers them to the corresponding address space pointer for 32-bit and 64-bit pointers.
(32/64-bit pointers added in https://reviews.llvm.org/D69639)

A large part of this patch is making these pointers ignore the address space
when doing things like overloading and casting.

https://bugs.llvm.org/show_bug.cgi?id=42359

Reviewers: rnk, rsmith

Subscribers: jholewinski, jvesely, nhaehnle, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D71039
2019-12-18 10:41:12 -08:00
Erich Keane 1ed832e424 Reland [NFC-I] Remove hack for fp-classification builtins
The FP-classification builtins (__builtin_isfinite, etc) use variadic
packs in the definition file to mean an overload set.  Because of that,
floats were converted to doubles, which is incorrect. There WAS a patch
to remove the cast after the fact.

THis patch switches these builtins to just be custom type checking,
calls the implicit conversions for the integer members, and makes sure
the correct L->R casts are put into place, then does type checking like
normal.

A future direction (that wouldn't be NFC) would consider making
conversions for the floating point parameter legal.

Note: The initial patch for this missed that certain systems need to
still convert half to float, since they dont' support that type.
2019-12-17 06:58:29 -08:00
Richard Smith 4b00299958 [c++20] Add deprecation warnings for the expression forms deprecated by P1120R0.
This covers:
 * usual arithmetic conversions (comparisons, arithmetic, conditionals)
   between different enumeration types
 * usual arithmetic conversions between enums and floating-point types
 * comparisons between two operands of array type

The deprecation warnings are on-by-default (in C++20 compilations); it
seems likely that these forms will become ill-formed in C++23, so
warning on them now by default seems wise.

For the first two bullets, off-by-default warnings were also added for
all the cases where we didn't already have warnings (covering language
modes prior to C++20). These warnings are in subgroups of the existing
-Wenum-conversion (except that the first case is not warned on if either
enumeration type is anonymous, consistent with our existing
-Wenum-conversion warnings).
2019-12-16 17:49:45 -08:00
Erich Keane 3f22b4721e Revert "[NFC-I] Remove hack for fp-classification builtins"
This reverts commit b1e542f302.

The original 'hack' didn't chop out fp-16 to double conversions, so
systems that use FP16ConversionIntrinsics end up in IR-CodeGen with an
i16 type isntead of a float type (like PPC64-BE).  The bots noticed
this.

Reverting until I figure out how to fix this
2019-12-16 14:01:51 -08:00
Erich Keane b1e542f302 [NFC-I] Remove hack for fp-classification builtins
The FP-classification builtins (__builtin_isfinite, etc) use variadic
packs in the definition file to mean an overload set.  Because of that,
floats were converted to doubles, which is incorrect. There WAS a patch
to remove the cast after the fact.

THis patch switches these builtins to just be custom type checking,
calls the implicit conversions for the integer members, and makes sure
the correct L->R casts are put into place, then does type checking like
normal.

A future direction (that wouldn't be NFC) would consider making
conversions for the floating point parameter legal.
2019-12-16 12:22:55 -08:00
Mark de Wever b6d386f6f9 [Wdocumentation] Use C2x/C++14 deprecated attribute
This replaces the non-standard __attribute__((deprecated)) with the
standard [[deprecated]] when compiling in C2x/C++14 mode.

Discovered while looking at https://bugs.llvm.org/show_bug.cgi?id=43753

Differential Revision: https://reviews.llvm.org/D71141
2019-12-10 21:16:18 +01:00
Mark de Wever b972f2d05e [Wdocumentation] Properly place deprecated attribute
It is now placed before the function:
- allows to replace __attribute__((deprecated)) with [[deprecated]].
- required for trailing returns.

Fixes bug: https://bugs.llvm.org/show_bug.cgi?id=43753

Differential Revision: https://reviews.llvm.org/D71140
2019-12-10 21:16:12 +01:00
Mark de Wever 85fff898bb [Wdocumentation] Use the command marker.
Use the proper marker for -Wdocumentation-deprecated-sync instead of
hard-coded the backslash.

Discovered while looking at https://bugs.llvm.org/show_bug.cgi?id=43753

Differential Revision: https://reviews.llvm.org/D71139
2019-12-10 21:16:07 +01:00
Carey Williams 76fd58d0fe Revert "[ARM] Allocatable Global Register Variables for ARM"
This reverts commit 2d739f98d8.
2019-11-29 17:01:05 +00:00
Simon Atanasyan f4d32ae75b [mips] Check that features required by built-ins are enabled
Now Clang does not check that features required by built-in functions
are enabled. That causes errors in the backend reported in PR44018.

This patch fixes this bug by checking that required features
are enabled.

This should fix PR44018.

Differential Revision: https://reviews.llvm.org/D70808
2019-11-29 00:23:00 +03:00
Gabor Horvath bcd0798c47 [LifetimeAnalysis] Fix PR44150
References need somewhat special treatment. While copying a gsl::Pointer
will propagate the points-to set, creating an object from a reference
often behaves more like a dereference operation.

Differential Revision: https://reviews.llvm.org/D70755
2019-11-27 09:15:14 -08:00
Yaxun (Sam) Liu ded2490494 Workaround for EvalInfo ctor for MSVC 2017
Current EvalInfo ctor causes EnableNewConstInterp to be true even though
it is supposed to be false on MSVC 2017. This is because a virtual function
getLangOpts() is called in member initializer lists, whereas on MSVC
member ctors are called before function virtual function pointers are
initialized.

This patch fixes that.

Differential Revision: https://reviews.llvm.org/D70729
2019-11-26 21:43:29 -05:00
Dávid Bolvanský ba4017670e [Diagnostics] Warn for comparison with string literals expanded from macro (PR44064)
Summary:
As noted in PR, we have a poor test coverage for this warning. I think macro support was just overlooked. GCC warns in these cases.
Clang missed a real bug in the code I am working with, GCC caught it.

Reviewers: aaron.ballman

Reviewed By: aaron.ballman

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70624
2019-11-24 19:40:32 +01:00
Akira Hatanaka 825235c140 Revert "[Sema] Use the canonical type in function isVector"
This reverts commit a6150b48ce.
The commit broke a few neon CodeGen tests.
2019-11-22 13:48:39 -08:00
Akira Hatanaka a6150b48ce [Sema] Use the canonical type in function isVector
This fixes an assertion in Sema::CreateBuiltinBinOp that fails when one
of the vector operand's element type is a typedef of __fp16.

rdar://problem/55983556
2019-11-22 12:57:24 -08:00
Bill Wendling 2b795637b9 Fix typo to separate "-x" from warning flag. 2019-11-22 12:51:41 -08:00
Bill Wendling 9180f8a574 Don't report "main" as missing a prototype in freestanding mode
Summary:
A user may want to use freestanding mode with the standard "main" entry
point. It's not useful to warn about a missing prototype as it's not
typical to have a prototype for "main".

Reviewers: efriedma, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: aaron.ballman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70588
2019-11-22 12:35:43 -08:00
Tim Northover 5cf58768cb Atomics: support min/max orthogonally
We seem to have been gradually growing support for atomic min/max operations
(exposing longstanding IR atomicrmw instructions). But until now there have
been gaps in the expected intrinsics. This adds support for the C11-style
intrinsics (i.e. taking _Atomic, rather than individually blessed by C11
standard), and the variants that return the new value instead of the original
one.

That way, people won't be misled by trying one form and it not working, and the
front-end is more friendly to people using _Atomic types, as we recommend.
2019-11-21 10:37:56 +00:00
Erik Pilkington d9957c7405 [Sema] Add a 'Semantic' parameter to Expr::isKnownToHaveBooleanValue
Some clients of this function want to know about any expression that is known
to produce a 0/1 value, and others care about expressions that are semantically
boolean.

This fixes a -Wswitch-bool regression I introduced in 8bfb353bb3, pointed out
by Chris Hamilton!
2019-11-20 16:29:31 -08:00
Sam McCall a433e7141f [AST] Attach comment in `/** doc */ typedef struct A {} B` to B as well as A.
Summary:
Semantically they're the same thing, and it's important when the underlying
struct is anonymous.

There doesn't seem to be a problem attaching the same comment to multiple things
as it already happens with `/** doc */ int a, b;`

This affects an Index test but the results look better (name present, USR points
to the typedef).

Fixes https://github.com/clangd/clangd/issues/189

Reviewers: kadircet, lh123

Subscribers: ilya-biryukov, jkorous, arphaman, usaxena95, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70203
2019-11-18 11:09:23 +01:00
Anna Welker 2d739f98d8 [ARM] Allocatable Global Register Variables for ARM
Provides support for using r6-r11 as globally scoped
      register variables. This requires a -ffixed-rN flag
      in order to reserve rN against general allocation.

      If for a given GRV declaration the corresponding flag
      is not found, or the the register in question is the
      target's FP, we fail with a diagnostic.

      Differential Revision: https://reviews.llvm.org/D68862
2019-11-18 10:07:37 +00:00
Momchil Velikov aa6d48fa70 Implement target(branch-protection) attribute for AArch64
This patch implements `__attribute__((target("branch-protection=...")))`
in a manner, compatible with the analogous GCC feature:

https://gcc.gnu.org/onlinedocs/gcc-9.2.0/gcc/AArch64-Function-Attributes.html#AArch64-Function-Attributes

Differential Revision: https://reviews.llvm.org/D68711
2019-11-15 15:40:46 +00:00
Simon Tatham 9e37892773 [ARM,MVE] Add intrinsics for vector get/set lane.
This adds the `vgetq_lane` and `vsetq_lane` families, to copy between
a scalar and a specified lane of a vector.

One of the new `vgetq_lane` intrinsics returns a `float16_t`, which
causes a compile error if `%clang_cc1` doesn't get the option
`-fallow-half-arguments-and-returns`. The driver passes that option to
cc1 already, but I've had to edit all the explicit cc1 command lines
in the existing MVE intrinsics tests.

A couple of fixes are included for the code I wrote up front in
MveEmitter to support lane-index immediates (and which nothing has
tested until now): the type was wrong (`uint32_t` instead of `int`)
and the range was off by one.

I've also added a method of bypassing the default promotion to `i32`
that is done by the MveEmitter code generation: it's sensible to
promote short scalars like `i16` to `i32` if they're going to be
passed to custom IR intrinsics representing a machine instruction
operating on GPRs, but not if they're going to be passed to standard
IR operations like `insertelement` which expect the exact type.

Reviewers: ostannard, MarkMurrayARM, dmgreen

Reviewed By: dmgreen

Subscribers: kristof.beyls, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D70188
2019-11-15 09:53:58 +00:00
Yonghong Song dd16b3fe25 [BPF] Restrict preserve_access_index attribute to C only
This patch is a follow-up for commit 4e2ce228ae
  [BPF] Add preserve_access_index attribute for record definition
to restrict attribute for C only. A new test case is added
to check for this restriction.

Additional code polishing is done based on
Aaron Ballman's suggestion in https://reviews.llvm.org/D69759/new/.

Differential Revision: https://reviews.llvm.org/D70257
2019-11-14 14:14:59 -08:00
Yonghong Song 4e2ce228ae [BPF] Add preserve_access_index attribute for record definition
This is a resubmission for the previous reverted commit
9434360401 with the same subject. This commit fixed the
segfault issue and addressed additional review comments.

This patch introduced a new bpf specific attribute which can
be added to struct or union definition. For example,
  struct s { ... } __attribute__((preserve_access_index));
  union u { ... } __attribute__((preserve_access_index));
The goal is to simplify user codes for cases
where preserve access index happens for certain struct/union,
so user does not need to use clang __builtin_preserve_access_index
for every members.

The attribute has no effect if -g is not specified.

When the attribute is specified and -g is specified, any member
access defined by that structure or union, including array subscript
access and inner records, will be preserved through
  __builtin_preserve_{array,struct,union}_access_index()
IR intrinsics, which will enable relocation generation
in bpf backend.

The following is an example to illustrate the usage:
  -bash-4.4$ cat t.c
  #define __reloc__ __attribute__((preserve_access_index))
  struct s1 {
    int c;
  } __reloc__;

  struct s2 {
    union {
      struct s1 b[3];
    };
  } __reloc__;

  struct s3 {
    struct s2 a;
  } __reloc__;

  int test(struct s3 *arg) {
    return arg->a.b[2].c;
  }
  -bash-4.4$ clang -target bpf -g -S -O2 t.c

A relocation with access string "0:0:0:0:2:0" will be generated
representing access offset of arg->a.b[2].c.

forward declaration with attribute is also handled properly such
that the attribute is copied and populated in real record definition.

Differential Revision: https://reviews.llvm.org/D69759
2019-11-13 08:23:44 -08:00
Weverything 9740f9f0b6 Add -Wtautological-compare to -Wall
Some warnings in -Wtautological-compare subgroups are DefaultIgnore.
Adding this group to -Wmost, which is part of -Wall, will aid in their
discoverability.

Differential Revision: https://reviews.llvm.org/D69292
2019-11-12 14:36:57 -08:00
Tim Northover 44e5879f0f AArch64: add arm64_32 support to Clang. 2019-11-12 12:45:18 +00:00
Dávid Bolvanský 1da13237a4 [Diagnostics] Try to improve warning message for -Wreturn-type
Summary: I agree with https://easyaspi314.github.io/gcc-vs-clang.html?fbclid=IwAR1VA0qxiWVUusOQUv5z7JESS7ZpeJy-UqAI5mnJscofGLqXcqeErIUB2gU, current warning message is not very good. We should try to improve it..

Reviewers: rsmith, aaron.ballman, easyaspi314

Reviewed By: aaron.ballman

Subscribers: arphaman, Quuxplusone, mehdi_amini, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D69762
2019-11-09 17:54:58 +01:00
Yonghong Song 9434360401 Revert "[BPF] Add preserve_access_index attribute for record definition"
This reverts commit 4a5aa1a7bf.

There are some other test failures. Investigate them first.
2019-11-09 08:32:44 -08:00
Yonghong Song 4a5aa1a7bf [BPF] Add preserve_access_index attribute for record definition
This patch introduced a new bpf specific attribute which can
be added to struct or union definition. For example,
  struct s { ... } __attribute__((preserve_access_index));
  union u { ... } __attribute__((preserve_access_index));
The goal is to simplify user codes for cases
where preserve access index happens for certain struct/union,
so user does not need to use clang __builtin_preserve_access_index
for every members.

The attribute has no effect if -g is not specified.

When the attribute is specified and -g is specified, any member
access defined by that structure or union, including array subscript
access and inner records, will be preserved through
  __builtin_preserve_{array,struct,union}_access_index()
IR intrinsics, which will enable relocation generation
in bpf backend.

The following is an example to illustrate the usage:
  -bash-4.4$ cat t.c
  #define __reloc__ __attribute__((preserve_access_index))
  struct s1 {
    int c;
  } __reloc__;

  struct s2 {
    union {
      struct s1 b[3];
    };
  } __reloc__;

  struct s3 {
    struct s2 a;
  } __reloc__;

  int test(struct s3 *arg) {
    return arg->a.b[2].c;
  }
  -bash-4.4$ clang -target bpf -g -S -O2 t.c

A relocation with access string "0:0:0:0:2:0" will be generated
representing access offset of arg->a.b[2].c.

forward declaration with attribute is also handled properly such
that the attribute is copied and populated in real record definition.

Differential Revision: https://reviews.llvm.org/D69759
2019-11-09 08:17:12 -08:00
Reid Kleckner 7177ce978e [SEH] Defer checking filter expression types until instantiaton
While here, wordsmith the error a bit. Now clang says:
  error: filter expression has non-integral type 'Foo'

Fixes PR43779

Reviewers: amccarth

Differential Revision: https://reviews.llvm.org/D69969
2019-11-07 14:52:04 -08:00
Dávid Bolvanský 01b10bc7b1 [Diagnostics] Teach -Wnull-dereference about address_space attribute
Summary:
Clang should not warn for:

> test.c:2:12: warning: indirection of non-volatile null pointer will be deleted,
>       not trap [-Wnull-dereference]
>     return *(int __attribute__((address_space(256))) *) 0;
>            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Solves PR42292.

Reviewers: aaron.ballman, rsmith

Reviewed By: aaron.ballman

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D69664
2019-11-07 22:43:27 +01:00
Simon Tatham 6c3fee47a6 [ARM,MVE] Add intrinsics for gather/scatter load/stores.
This patch adds two new families of intrinsics, both of which are
memory accesses taking a vector of locations to load from / store to.

The vldrq_gather_base / vstrq_scatter_base intrinsics take a vector of
base addresses, and an immediate offset to be added consistently to
each one. vldrq_gather_offset / vstrq_scatter_offset take a scalar
base address, and a vector of offsets to add to it. The
'shifted_offset' variants also multiply each offset by the element
size type, so that the vector is effectively of array indices.

At the IR level, these operations are represented by a single set of
four IR intrinsics: {gather,scatter} × {base,offset}. The other
details (signed/unsigned, shift, and memory element size as opposed to
vector element size) are all specified by IR intrinsic polymorphism
and immediate operands, because that made the selection job easier
than making a huge family of similarly named intrinsics.

I considered using the standard IR representations such as
llvm.masked.gather, but they're not a good fit. In order to use
llvm.masked.gather to represent a gather_offset load with element size
smaller than a pointer, you'd have to expand the <8 x i16> vector of
offsets into an <8 x i16*> vector of pointers, which would be split up
during legalization, so you'd spend most of your time undoing the mess
it had made. Also, ISel support for llvm.masked.gather would be easy
enough in a trivial way (you can expand it into a gather-base load
with a zero immediate offset), but instruction-selecting lots of
fiddly idioms back into all the _other_ MVE load instructions would be
much more work. So I think dedicated IR intrinsics are the more
sensible approach, at least for the moment.

On the clang tablegen side, I've added two new features to the
Tablegen source accepted by MveEmitter: a 'CopyKind' type node for
defining a type that varies with the parameter type (it lets you ask
for an unsigned integer type of the same width as the parameter), and
an 'unsignedflag' value node for passing an immediate IR operand which
is 0 for a signed integer type or 1 for an unsigned one. That lets me
write each kind of intrinsic just once and get all its subtypes and
immediate arguments generated automatically.

Also I've tweaked the handling of pointer-typed values in the code
generation part of MveEmitter: they're generated as Address rather
than Value (i.e. including an alignment) so that they can be given to
the ordinary IR load and store operations, but I'd omitted the code to
convert them back to Value when they're going to be used as an
argument to an IR intrinsic.

On the MC side, I've enhanced MVEVectorVTInfo so that it can tell you
not only the full assembly-language suffix for a given vector type
(like 's32' or 'u16') but also the numeric-only one used by store
instructions (just '32' or '16').

Reviewers: dmgreen

Subscribers: kristof.beyls, hiraditya, cfe-commits, llvm-commits

Tags: #clang, #llvm

Differential Revision: https://reviews.llvm.org/D69791
2019-11-06 09:01:42 +00:00
Guillaume Chatelet 5607ff12fa Fix missing memcpy builtin on ppc64be
See D68028
2019-10-29 16:35:32 +01:00
Guillaume Chatelet 98f3151a7d [clang] Add no_builtin attribute
Summary:
This is a follow up on https://reviews.llvm.org/D61634
This patch is simpler and only adds the no_builtin attribute.

Reviewers: tejohnson, courbet, theraven, t.p.northover, jdoerfert

Subscribers: mgrang, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68028

This is a re-submit after it got reverted in https://reviews.llvm.org/rGbd8791610948 since the breakage doesn't seem to come from this patch.
2019-10-29 15:50:29 +01:00
Vlad Tsyrklevich ad531fff81 Revert "[clang] Add no_builtin attribute"
This reverts commit bd87916109. It was
causing ASan/MSan failures on the sanitizer buildbots.
2019-10-28 15:21:59 -07:00
Guillaume Chatelet bd87916109 [clang] Add no_builtin attribute
Summary:
This is a follow up on https://reviews.llvm.org/D61634
This patch is simpler and only adds the no_builtin attribute.

Reviewers: tejohnson, courbet, theraven, t.p.northover, jdoerfert

Subscribers: mgrang, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68028
2019-10-28 17:30:11 +01:00
David Goldman 7a2b704bf0 [Sema][Typo Correction] Fix another infinite loop on ambiguity
See also: D67515

- For the given call expression we would end up repeatedly
   trying to transform the same expression over and over again

- Fix is to keep the old TransformCache when checking for ambiguity

Differential Revision: https://reviews.llvm.org/D69060
2019-10-25 13:20:27 -04:00
Simon Tatham 7c11da0cfd [clang] New __attribute__((__clang_arm_mve_alias)).
This allows you to declare a function with a name of your choice (say
`foo`), but have clang treat it as if it were a builtin function (say
`__builtin_foo`), by writing

  static __inline__ __attribute__((__clang_arm_mve_alias(__builtin_foo)))
  int foo(args);

I'm intending to use this for the ACLE intrinsics for MVE, which have
to be polymorphic on their argument types and also need to be
implemented by builtins. To avoid having to implement the polymorphism
with several layers of nested _Generic and make error reporting
hideous, I want to make all the user-facing intrinsics correspond
directly to clang builtins, so that after clang resolves
__attribute__((overloadable)) polymorphism it's already holding the
right BuiltinID for the intrinsic it selected.

However, this commit itself just introduces the new attribute, and
doesn't use it for anything.

To avoid unanticipated side effects if this attribute is used to make
aliases to other builtins, there's a restriction mechanism: only
(BuiltinID, alias) pairs that are approved by the function
ArmMveAliasValid() will be permitted. At present, that function
doesn't permit anything, because the Tablegen that will generate its
list of valid pairs isn't yet implemented. So the only test of this
facility is one that checks that an unapproved builtin _can't_ be
aliased.

Reviewers: dmgreen, miyuki, ostannard

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67159
2019-10-24 16:33:13 +01:00
Richard Trieu 637af4cc37 Add -Wbitwise-conditional-parentheses to warn on mixing '|' and '&' with "?:"
Extend -Wparentheses to cover mixing bitwise-and and bitwise-or with the
conditional operator. There's two main cases seen with this:

unsigned bits1 = 0xf0 | cond ? 0x4 : 0x1;
unsigned bits2 = cond1 ? 0xf0 : 0x10 | cond2 ? 0x5 : 0x2;

// Intended order of evaluation:
unsigned bits1 = 0xf0 | (cond ? 0x4 : 0x1);
unsigned bits2 = (cond1 ? 0xf0 : 0x10) | (cond2 ? 0x5 : 0x2);

// Actual order of evaluation:
unsigned bits1 = (0xf0 | cond) ? 0x4 : 0x1;
unsigned bits2 = cond1 ? 0xf0 : ((0x10 | cond2) ? 0x5 : 0x2);

Differential Revision: https://reviews.llvm.org/D66043

llvm-svn: 375326
2019-10-19 01:47:49 +00:00
Richard Trieu 8b0d14a8f0 New tautological warning for bitwise-or with non-zero constant always true.
Taking a value and the bitwise-or it with a non-zero constant will always
result in a non-zero value. In a boolean context, this is always true.

if (x | 0x4) {}  // always true, intended '&'

This patch creates a new warning group -Wtautological-bitwise-compare for this
warning. It also moves in the existing tautological bitwise comparisons into
this group. A few other changes were needed to the CFGBuilder so that all bool
contexts would be checked. The warnings in -Wtautological-bitwise-compare will
be off by default due to using the CFG.

Fixes: https://bugs.llvm.org/show_bug.cgi?id=42666
Differential Revision: https://reviews.llvm.org/D66046

llvm-svn: 375318
2019-10-19 00:57:23 +00:00
Dmitry Mikulin f14642f2f1 Added support for "#pragma clang section relro=<name>"
Differential Revision: https://reviews.llvm.org/D68806

llvm-svn: 374934
2019-10-15 18:31:10 +00:00
Erich Keane add0786dba Fix test failure with 374562 on Hexagon
__builtin_assume_aligned takes a size_t which is a 32 bit int on
hexagon.  Thus, the constant gets converted to a 32 bit value, resulting
in 0 not being a power of 2.  This patch changes the constant being
passed to 2**30 so that it fails, but doesnt exceed 30 bits.

llvm-svn: 374569
2019-10-11 16:30:45 +00:00
Erich Keane f759395994 Reland r374450 with Richard Smith's comments and test fixed.
The behavior from the original patch has changed, since we're no longer
allowing LLVM to just ignore the alignment.  Instead, we're just
assuming the maximum possible alignment.

Differential Revision: https://reviews.llvm.org/D68824

llvm-svn: 374562
2019-10-11 14:59:44 +00:00
Nico Weber b556085d81 Revert 374450 "Fix __builtin_assume_aligned with too large values."
The test fails on Windows, with

  error: 'warning' diagnostics expected but not seen:
    File builtin-assume-aligned.c Line 62: requested alignment
        must be 268435456 bytes or smaller; assumption ignored
  error: 'warning' diagnostics seen but not expected:
    File builtin-assume-aligned.c Line 62: requested alignment
        must be 8192 bytes or smaller; assumption ignored

llvm-svn: 374456
2019-10-10 21:34:32 +00:00
Erich Keane 31e454c1ec Fix __builtin_assume_aligned with too large values.
Code to handle __builtin_assume_aligned was allowing larger values, but
would convert this to unsigned along the way. This patch removes the
EmitAssumeAligned overloads that take unsigned to do away with this
problem.

Additionally, it adds a warning that values greater than 1 <<29 are
ignored by LLVM.

Differential Revision: https://reviews.llvm.org/D68824

llvm-svn: 374450
2019-10-10 21:08:28 +00:00
Reid Kleckner 5e866e411c Add -fgnuc-version= to control __GNUC__ and other GCC macros
I noticed that compiling on Windows with -fno-ms-compatibility had the
side effect of defining __GNUC__, along with __GNUG__, __GXX_RTTI__, and
a number of other macros for GCC compatibility. This is undesirable and
causes Chromium to do things like mix __attribute__ and __declspec,
which doesn't work. We should have a positive language option to enable
GCC compatibility features so that we can experiment with
-fno-ms-compatibility on Windows. This change adds -fgnuc-version= to be
that option.

My issue aside, users have, for a long time, reported that __GNUC__
doesn't match their expectations in one way or another. We have
encouraged users to migrate code away from this macro, but new code
continues to be written assuming a GCC-only environment. There's really
nothing we can do to stop that. By adding this flag, we can allow them
to choose their own adventure with __GNUC__.

This overlaps a bit with the "GNUMode" language option from -std=gnu*.
The gnu language mode tends to enable non-conforming behaviors that we'd
rather not enable by default, but the we want to set things like
__GXX_RTTI__ by default, so I've kept these separate.

Helps address PR42817

Reviewed By: hans, nickdesaulniers, MaskRay

Differential Revision: https://reviews.llvm.org/D68055

llvm-svn: 374449
2019-10-10 21:04:25 +00:00
Yonghong Song 05e46979d2 [BPF] do compile-once run-everywhere relocation for bitfields
A bpf specific clang intrinsic is introduced:
   u32 __builtin_preserve_field_info(member_access, info_kind)
Depending on info_kind, different information will
be returned to the program. A relocation is also
recorded for this builtin so that bpf loader can
patch the instruction on the target host.
This clang intrinsic is used to get certain information
to facilitate struct/union member relocations.

The offset relocation is extended by 4 bytes to
include relocation kind.
Currently supported relocation kinds are
 enum {
    FIELD_BYTE_OFFSET = 0,
    FIELD_BYTE_SIZE,
    FIELD_EXISTENCE,
    FIELD_SIGNEDNESS,
    FIELD_LSHIFT_U64,
    FIELD_RSHIFT_U64,
 };
for __builtin_preserve_field_info. The old
access offset relocation is covered by
    FIELD_BYTE_OFFSET = 0.

An example:
struct s {
    int a;
    int b1:9;
    int b2:4;
};
enum {
    FIELD_BYTE_OFFSET = 0,
    FIELD_BYTE_SIZE,
    FIELD_EXISTENCE,
    FIELD_SIGNEDNESS,
    FIELD_LSHIFT_U64,
    FIELD_RSHIFT_U64,
};

void bpf_probe_read(void *, unsigned, const void *);
int field_read(struct s *arg) {
  unsigned long long ull = 0;
  unsigned offset = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_OFFSET);
  unsigned size = __builtin_preserve_field_info(arg->b2, FIELD_BYTE_SIZE);
 #ifdef USE_PROBE_READ
  bpf_probe_read(&ull, size, (const void *)arg + offset);
  unsigned lshift = __builtin_preserve_field_info(arg->b2, FIELD_LSHIFT_U64);
 #if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
  lshift = lshift + (size << 3) - 64;
 #endif
 #else
  switch(size) {
  case 1:
    ull = *(unsigned char *)((void *)arg + offset); break;
  case 2:
    ull = *(unsigned short *)((void *)arg + offset); break;
  case 4:
    ull = *(unsigned int *)((void *)arg + offset); break;
  case 8:
    ull = *(unsigned long long *)((void *)arg + offset); break;
  }
  unsigned lshift = __builtin_preserve_field_info(arg->b2, FIELD_LSHIFT_U64);
 #endif
  ull <<= lshift;
  if (__builtin_preserve_field_info(arg->b2, FIELD_SIGNEDNESS))
    return (long long)ull >> __builtin_preserve_field_info(arg->b2, FIELD_RSHIFT_U64);
  return ull >> __builtin_preserve_field_info(arg->b2, FIELD_RSHIFT_U64);
}

There is a minor overhead for bpf_probe_read() on big endian.

The code and relocation generated for field_read where bpf_probe_read() is
used to access argument data on little endian mode:
        r3 = r1
        r1 = 0
        r1 = 4  <=== relocation (FIELD_BYTE_OFFSET)
        r3 += r1
        r1 = r10
        r1 += -8
        r2 = 4  <=== relocation (FIELD_BYTE_SIZE)
        call bpf_probe_read
        r2 = 51 <=== relocation (FIELD_LSHIFT_U64)
        r1 = *(u64 *)(r10 - 8)
        r1 <<= r2
        r2 = 60 <=== relocation (FIELD_RSHIFT_U64)
        r0 = r1
        r0 >>= r2
        r3 = 1  <=== relocation (FIELD_SIGNEDNESS)
        if r3 == 0 goto LBB0_2
        r1 s>>= r2
        r0 = r1
LBB0_2:
        exit

Compare to the above code between relocations FIELD_LSHIFT_U64 and
FIELD_LSHIFT_U64, the code with big endian mode has four more
instructions.
        r1 = 41   <=== relocation (FIELD_LSHIFT_U64)
        r6 += r1
        r6 += -64
        r6 <<= 32
        r6 >>= 32
        r1 = *(u64 *)(r10 - 8)
        r1 <<= r6
        r2 = 60   <=== relocation (FIELD_RSHIFT_U64)

The code and relocation generated when using direct load.
        r2 = 0
        r3 = 4
        r4 = 4
        if r4 s> 3 goto LBB0_3
        if r4 == 1 goto LBB0_5
        if r4 == 2 goto LBB0_6
        goto LBB0_9
LBB0_6:                                 # %sw.bb1
        r1 += r3
        r2 = *(u16 *)(r1 + 0)
        goto LBB0_9
LBB0_3:                                 # %entry
        if r4 == 4 goto LBB0_7
        if r4 == 8 goto LBB0_8
        goto LBB0_9
LBB0_8:                                 # %sw.bb9
        r1 += r3
        r2 = *(u64 *)(r1 + 0)
        goto LBB0_9
LBB0_5:                                 # %sw.bb
        r1 += r3
        r2 = *(u8 *)(r1 + 0)
        goto LBB0_9
LBB0_7:                                 # %sw.bb5
        r1 += r3
        r2 = *(u32 *)(r1 + 0)
LBB0_9:                                 # %sw.epilog
        r1 = 51
        r2 <<= r1
        r1 = 60
        r0 = r2
        r0 >>= r1
        r3 = 1
        if r3 == 0 goto LBB0_11
        r2 s>>= r1
        r0 = r2
LBB0_11:                                # %sw.epilog
        exit

Considering verifier is able to do limited constant
propogation following branches. The following is the
code actually traversed.
        r2 = 0
        r3 = 4   <=== relocation
        r4 = 4   <=== relocation
        if r4 s> 3 goto LBB0_3
LBB0_3:                                 # %entry
        if r4 == 4 goto LBB0_7
LBB0_7:                                 # %sw.bb5
        r1 += r3
        r2 = *(u32 *)(r1 + 0)
LBB0_9:                                 # %sw.epilog
        r1 = 51   <=== relocation
        r2 <<= r1
        r1 = 60   <=== relocation
        r0 = r2
        r0 >>= r1
        r3 = 1
        if r3 == 0 goto LBB0_11
        r2 s>>= r1
        r0 = r2
LBB0_11:                                # %sw.epilog
        exit

For native load case, the load size is calculated to be the
same as the size of load width LLVM otherwise used to load
the value which is then used to extract the bitfield value.

Differential Revision: https://reviews.llvm.org/D67980

llvm-svn: 374099
2019-10-08 18:23:17 +00:00
James Clarke 67f542aba7 [Diagnostics] Silence -Wsizeof-array-div for character buffers
Summary:
Character buffers are sometimes used to represent a pool of memory that
contains non-character objects, due to them being synonymous with a stream of
bytes on almost all modern architectures. Often, when interacting with hardware
devices, byte buffers are therefore used as an intermediary and so we can end
Character buffers are sometimes used to represent a pool of memory that
contains non-character objects, due to them being synonymous with a stream of
bytes on almost all modern architectures. Often, when interacting with hardware
devices, byte buffers are therefore used as an intermediary and so we can end
up generating lots of false-positives.

Moreover, due to the ability of character pointers to alias non-character
pointers, the strict aliasing violations that would generally be implied by the
calculations caught by the warning (if the calculation itself is in fact
correct) do not apply here, and so although the length calculation may be
wrong, that is the only possible issue.

Reviewers: rsmith, xbolva00, thakis

Reviewed By: xbolva00, thakis

Subscribers: thakis, lebedev.ri, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68526

llvm-svn: 374035
2019-10-08 11:34:02 +00:00
David Bolvansky aaea76ba02 [Diagnostics] Emit better -Wbool-operation's warning message if we known that the result is always true
llvm-svn: 373973
2019-10-07 21:57:03 +00:00
David Bolvansky 559265c8da [Diagnostics] Use Expr::isKnownToHaveBooleanValue() to check bitwise negation of bool in languages without a bool type
Thanks for this advice, Richard Trieu!

llvm-svn: 373817
2019-10-05 08:02:11 +00:00
Yuanfang Chen 442ddffe13 [clang] fix a typo from r372531
Reviewers: xbolva00

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D68482

llvm-svn: 373792
2019-10-04 21:37:20 +00:00
Erik Pilkington f7766b1ed4 [Sema] Split out -Wformat-type-confusion from -Wformat-pedantic
The warnings now in -Wformat-type-confusion don't align with how we interpret
'pedantic' in clang, and don't belong in -pedantic.

Differential revision: https://reviews.llvm.org/D67775

llvm-svn: 373774
2019-10-04 19:20:27 +00:00
Sam McCall f44ca7f6eb Further improve -Wbool-operation bitwise negation message
llvm-svn: 373749
2019-10-04 14:11:05 +00:00
David Bolvansky 5e851ad6c1 [NFCI] Improve the -Wbool-operation's warning message
Based on the request from the post commit review. Also added one new test.

llvm-svn: 373743
2019-10-04 12:55:13 +00:00
David Bolvansky b4ee523ffc [Diagnostics] Bitwise negation of a boolean expr always evaluates to true; warn with -Wbool-operation
Requested here:
http://lists.llvm.org/pipermail/cfe-dev/2019-October/063452.html

llvm-svn: 373614
2019-10-03 15:17:59 +00:00
David Bolvansky 00d632e089 [Diagnostics] Make -Wenum-compare-conditional off by default
Too many false positives, eg. in Chromium.

llvm-svn: 373371
2019-10-01 18:12:13 +00:00
David Bolvansky 362055d1fa [Diagnostics] Move warning into the subgroup (-Wenum-compare-conditional)
llvm-svn: 373345
2019-10-01 15:44:38 +00:00
David Bolvansky 471910d754 [Diagnostics] Warn if enumeration type mismatch in conditional expression
Summary:
- Useful warning
- GCC compatibility (GCC warns in C++ mode)

Reviewers: rsmith, aaron.ballman

Reviewed By: aaron.ballman

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67919

llvm-svn: 373252
2019-09-30 19:55:50 +00:00
David Bolvansky 275e4df115 [Diagnostics] Handle tautological left shifts in boolean context
llvm-svn: 372749
2019-09-24 13:14:18 +00:00
David Bolvansky 849fd28cf0 [Diagnostics] Do not diagnose unsigned shifts in boolean context (-Wint-in-bool-context)
I was looking at old GCC's patch. Current "trunk" version avoids warning for unsigned case, GCC warns only for signed shifts.

llvm-svn: 372708
2019-09-24 09:14:33 +00:00
David Bolvansky 28b38c277a [Diagnostics] Warn for enum constants in bool context (-Wint-in-bool-context; GCC compatibility)
Extracted from D63082.

llvm-svn: 372664
2019-09-23 22:09:49 +00:00
David Bolvansky 84ea41fd17 [Diagnostics] Warn if '<<' in bool context with -Wint-in-bool-context (GCC compatibility)
Extracted from D63082, addressed review comments related to a warning message.

llvm-svn: 372612
2019-09-23 14:21:08 +00:00
David Bolvansky 116e6cf36e [Diagnostics] Avoid -Wsizeof-array-div when dividing the size of a nested array by the size of the deepest base type
llvm-svn: 372600
2019-09-23 12:54:35 +00:00
Craig Topper e4c1765124 [X86] Require last argument to LWPINS/LWPVAL builtins to be an ICE. Add ImmArg to the llvm intrinsics.
Update the isel patterns to use timm instead of imm.

llvm-svn: 372534
2019-09-22 23:48:50 +00:00
David Bolvansky fb218170b4 [Diagnostics] Warn if ?: with integer constants always evaluates to true
Extracted from D63082. GCC has this warning under -Wint-in-bool-context, but as noted in the D63082's review, we should put it under TautologicalConstantCompare.

llvm-svn: 372531
2019-09-22 22:00:48 +00:00
Yonghong Song 91d5c2a035 [CLANG][BPF] permit any argument type for __builtin_preserve_access_index()
Commit c15aa241f8 ("[CLANG][BPF] change __builtin_preserve_access_index()
signature") changed the builtin function signature to
  PointerT __builtin_preserve_access_index(PointerT ptr)
with a pointer type as the argument/return type, where argument and
return types must be the same.

There is really no reason for this constraint. The builtin just
presented a code region so that IR builtins
  __builtin_{array, struct, union}_preserve_access_index
can be applied.

This patch removed the pointer type restriction to permit any
argument type as long as it is permitted by the compiler.

Differential Revision: https://reviews.llvm.org/D67883

llvm-svn: 372516
2019-09-22 17:33:48 +00:00
Richard Trieu 4c05de8c1d Merge and improve code that detects same value in comparisons.
-Wtautological-overlap-compare and self-comparison from -Wtautological-compare
relay on detecting the same operand in different locations.  Previously, each
warning had it's own operand checker.  Now, both are merged together into
one function that each can call.  The function also now looks through member
access and array accesses.

Differential Revision: https://reviews.llvm.org/D66045

llvm-svn: 372453
2019-09-21 03:02:26 +00:00
Richard Trieu 6541c7988b Improve -Wtautological-overlap-compare
Allow this warning to detect a larger number of constant values, including
negative numbers, and handle non-int types better.

Differential Revision: https://reviews.llvm.org/D66044

llvm-svn: 372448
2019-09-21 02:37:10 +00:00
Yonghong Song c15aa241f8 [CLANG][BPF] change __builtin_preserve_access_index() signature
The clang intrinsic __builtin_preserve_access_index() currently
has signature:
  const void * __builtin_preserve_access_index(const void * ptr)

This may cause compiler warning when:
  - parameter type is "volatile void *" or "const volatile void *", or
  - the assign-to type of the intrinsic does not have "const" qualifier.
Further, this signature does not allow dereference of the
builtin result pointer as it is a "const void *" type, which
adds extra step for the user to do type casting.

Let us change the signature to:
  PointerT __builtin_preserve_access_index(PointerT ptr)
such that the result and argument types are the same.
With this, directly dereferencing the builtin return value
becomes possible.

Differential Revision: https://reviews.llvm.org/D67734

llvm-svn: 372294
2019-09-19 02:59:43 +00:00
Erik Pilkington 5741d19f04 [Sema] Suppress -Wformat diagnostics for bool types when printed using %hhd
Also, add a diagnostic under -Wformat for printing a boolean value as a
character.

rdar://54579473

Differential revision: https://reviews.llvm.org/D66856

llvm-svn: 372247
2019-09-18 19:05:14 +00:00
Erik Pilkington 5c62152275 [Sema] Split of versions of -Wimplicit-{float,int}-conversion for Objective-C BOOL
Also, add a diagnostic group, -Wobjc-signed-char-bool, to control all these
related diagnostics.

rdar://51954400

Differential revision: https://reviews.llvm.org/D67559

llvm-svn: 372183
2019-09-17 21:11:51 +00:00
Erik Pilkington a1e29a3407 Use 'BOOL' instead of BOOL in diagnostic messages
Type names should be enclosed in single quotes.

llvm-svn: 372152
2019-09-17 18:02:45 +00:00
Richard Smith 9864269a0d Fix reliance on lax vector conversions in tests for x86 intrinsics.
llvm-svn: 372062
2019-09-17 03:56:28 +00:00
David Bolvansky b8185153f3 [Diagnostics] Added silence note for -Wsizeof-array-div; suggest extra parens
llvm-svn: 371924
2019-09-14 19:38:55 +00:00
David Goldman 6d18650421 [Sema][Typo Correction] Fix potential infite loop on ambiguity checks
Summary:
This fixes a bug introduced in D62648, where Clang could infinite loop
if it became stuck on a single TypoCorrection when it was supposed to
be testing ambiguous corrections. Although not a common case, it could
happen if there are multiple possible corrections with the same edit
distance.

The fix is simply to wipe the TypoExpr from the `TransformCache` so that
the call to `TransformTypoExpr` doesn't use the `CachedEntry`.

Reviewers: rsmith

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67515

llvm-svn: 371859
2019-09-13 14:43:24 +00:00
Richard Smith c624510f13 For PR17164: split -fno-lax-vector-conversion into three different
levels:

 -- none: no lax vector conversions [new GCC default]
 -- integer: only conversions between integer vectors [old GCC default]
 -- all: all conversions between same-size vectors [Clang default]

For now, Clang still defaults to "all" mode, but per my proposal on
cfe-dev (2019-04-10) the default will be changed to "integer" as soon as
that doesn't break lots of testcases. (Eventually I'd like to change the
default to "none" to match GCC and general sanity.)

Following GCC's behavior, the driver flag -flax-vector-conversions is
translated to -flax-vector-conversions=integer.

This reinstates r371805, reverted in r371813, with an additional fix for
lldb.

llvm-svn: 371817
2019-09-13 06:02:15 +00:00
Jonas Devlieghere 4aaa77e48d Revert "For PR17164: split -fno-lax-vector-conversion into three different"
This breaks the LLDB build. I tried reaching out to Richard, but haven't
gotten a reply yet.

llvm-svn: 371813
2019-09-13 05:16:59 +00:00
Richard Smith 49c4e58b75 For PR17164: split -fno-lax-vector-conversion into three different
levels:

 -- none: no lax vector conversions [new GCC default]
 -- integer: only conversions between integer vectors [old GCC default]
 -- all: all conversions between same-size vectors [Clang default]

For now, Clang still defaults to "all" mode, but per my proposal on
cfe-dev (2019-04-10) the default will be changed to "integer" as soon as
that doesn't break lots of testcases. (Eventually I'd like to change the
default to "none" to match GCC and general sanity.)

Following GCC's behavior, the driver flag -flax-vector-conversions is
translated to -flax-vector-conversions=integer.

llvm-svn: 371805
2019-09-13 02:20:00 +00:00
David Bolvansky 82d9e0e122 [NFC] Added triple to test file to avoid arm buildbots failures
llvm-svn: 371646
2019-09-11 18:55:56 +00:00
David Bolvansky 3240ad4ced [Diagnostics] Add -Wsizeof-array-div
Summary: Clang version of https://www.viva64.com/en/examples/v706/

Reviewers: rsmith

Differential Revision: https://reviews.llvm.org/D67287

llvm-svn: 371605
2019-09-11 10:59:47 +00:00
Reid Kleckner 7b4237d3cc Emit -Wmicrosoft-enum-value warning instead of error in MS ABI
Summary:
The first NFC change is to replace a getCXXABI().isMicrosoft() check
with getTriple().isWindowsMSVCEnvironment(). This code takes effect in
non-C++ compilations, so it doesn't make sense to check the C++ ABI. In
the MS ABI, enums are always considered to be "complete" because the
underlying type of an unfixed enum will always be 'int'. This behavior
was moved from -fms-compatibility to MS ABI back in r249656.

The second change is functional, and it downgrades an error to a warning
when the MS ABI is used rather than only under -fms-compatibility. The
reasoning is that it's unreasonable for the following code to reject the
following code for all MS ABI targets with -fno-ms-compatibility:
  enum Foo { Foo_Val = 0xDEADBEEF };
This is valid code for any other target, but in the MS ABI, Foo_Val just
happens to be negative. With this change, clang emits a
-Wmicrosoft-enum-value warning on this code, but compiles it without
error.

Fixes PR38478

Reviewers: hans, rsmith, STL_MSFT

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D67304

llvm-svn: 371581
2019-09-11 01:01:06 +00:00
Richard Smith 045b2270ce When evaluating a __builtin_constant_p conditional, always enter
constant-folding mode regardless of the original evaluation mode.

In order for this to be correct, we need to track whether we're checking
for a potential constant expression or checking for undefined behavior
separately from the evaluation mode enum, since we don't want to clobber
those states when entering constant-folding mode.

llvm-svn: 371557
2019-09-10 21:24:09 +00:00
Craig Topper ce2cb0f09e [X86] Allow _MM_FROUND_CUR_DIRECTION and _MM_FROUND_NO_EXC to be used together on instructions that only support SAE and not embedded rounding.
Current for SAE instructions we only allow _MM_FROUND_CUR_DIRECTION(bit 2) or _MM_FROUND_NO_EXC(bit 3) to be used as the immediate passed to the inrinsics. But these instructions don't perform rounding so _MM_FROUND_CUR_DIRECTION is just sort of a default placeholder when you don't want to suppress exceptions. Using _MM_FROUND_NO_EXC by itself is really bit equivalent to (_MM_FROUND_NO_EXC | _MM_FROUND_TO_NEAREST_INT) since _MM_FROUND_TO_NEAREST_INT is 0. Since we aren't rounding on these instructions we should also accept (_MM_FROUND_CUR_DIRECTION | _MM_FROUND_NO_EXC) as equivalent to (_MM_FROUND_NO_EXC). icc allows this, but gcc does not.

Differential Revision: https://reviews.llvm.org/D67289

llvm-svn: 371430
2019-09-09 17:48:05 +00:00
David Bolvansky 454e40eaf3 [NFCI] Unbreak buildbots
llvm-svn: 371226
2019-09-06 16:30:44 +00:00
David Bolvansky d1cc181d03 [NFC] Added new tests for r371222
llvm-svn: 371223
2019-09-06 16:18:18 +00:00
David Bolvansky fd07568074 [Diagnostics] Refactor code for -Wsizeof-pointer-div, catch more cases; also add -Wsizeof-array-div
Previously, -Wsizeof-pointer-div failed to catch:
const int *r;
sizeof(r) / sizeof(int);

Now fixed.
Also introduced -Wsizeof-array-div which catches bugs like:
sizeof(r) / sizeof(short);

(Array element type does not match type of sizeof operand).

llvm-svn: 371222
2019-09-06 16:12:48 +00:00
David Candler a59bffb576 [ARM] Add support for the s,j,x,N,O inline asm constraints
A number of inline assembly constraints are currently supported by LLVM, but rejected as invalid by Clang:

Target independent constraints:

s: An integer constant, but allowing only relocatable values

ARM specific constraints:

j: An immediate integer between 0 and 65535 (valid for MOVW)
x: A 32, 64, or 128-bit floating-point/SIMD register: s0-s15, d0-d7, or q0-q3
N: An immediate integer between 0 and 31 (Thumb1 only)
O: An immediate integer which is a multiple of 4 between -508 and 508. (Thumb1 only)

This patch adds support to Clang for the missing constraints along with some checks to ensure that the constraints are used with the correct target and Thumb mode, and that immediates are within valid ranges (at least where possible). The constraints are already implemented in LLVM, but just a couple of minor corrections to checks (V8M Baseline includes MOVW so should work with 'j', 'N' and 'O' shouldn't be valid in Thumb2) so that Clang and LLVM are in line with each other and the documentation.

Differential Revision: https://reviews.llvm.org/D65863

Change-Id: I18076619e319bac35fbb60f590c069145c9d9a0a
llvm-svn: 371079
2019-09-05 15:17:25 +00:00
Gabor Horvath 6f98400189 [LifetimeAnalysis] Fix some false positives
Differential Revision: https://reviews.llvm.org/D66806

llvm-svn: 370773
2019-09-03 16:17:24 +00:00
Dmitri Gribenko d94b42f422 [Wdocumentation] fixes an assertion failure with typedefed function and block pointer
Summary:
The assertion happens when compiling with -Wdocumentation with variable declaration to a typedefed function pointer. I not too familiar with the ObjC syntax but first two tests assert without this patch.

Fixes https://bugs.llvm.org/show_bug.cgi?id=42844

Reviewers: gribozavr

Reviewed By: gribozavr

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D66706

llvm-svn: 370677
2019-09-02 18:24:33 +00:00
Richard Smith 5030928d60 [c++20] Implement semantic restrictions for C++20 designated
initializers.

This has some interesting interactions with our existing extensions to
support C99 designated initializers as an extension in C++. Those are
resolved as follows:

 * We continue to permit the full breadth of C99 designated initializers
   in C++, with the exception that we disallow a partial overwrite of an
   initializer with a non-trivially-destructible type. (Full overwrite
   is OK, because we won't run the first initializer at all.)

 * The C99 extensions are disallowed in SFINAE contexts and during
   overload resolution, where they could change the meaning of valid
   programs.

 * C++20 disallows reordering of initializers. We only check for that for
   the simple cases that the C++20 rules permit (designators of the form
   '.field_name =' and continue to allow reordering in other cases).
   It would be nice to improve this behavior in future.

 * All C99 designated initializer extensions produce a warning by
   default in C++20 mode. People are going to learn the C++ rules based
   on what Clang diagnoses, so it's important we diagnose these properly
   by default.

 * In C++ <= 17, we apply the C++20 rules rather than the C99 rules, and
   so still diagnose C99 extensions as described above. We continue to
   accept designated C++20-compatible initializers in C++ <= 17 silently
   by default (but naturally still reject under -pedantic-errors).

This is not a complete implementation of P0329R4. In particular, that
paper introduces new non-C99-compatible syntax { .field { init } }, and
we do not support that yet.

This is based on a previous patch by Don Hinton, though I've made
substantial changes when addressing the above interactions.

Differential Revision: https://reviews.llvm.org/D59754

llvm-svn: 370544
2019-08-30 22:52:55 +00:00
Richard Smith 33e9be6c8b Refactor InitListChecker to check only a single (explicit) initializer
list, rather than recursively checking multiple lists in C.

This simplification is in preparation for making InitListChecker
maintain more state that's specific to the explicit initializer list,
particularly when handling designated initialization.

llvm-svn: 370418
2019-08-29 22:49:33 +00:00
Artem Dergachev e5c0994ddf [CFG] Fix CFG for statement-expressions in return values.
We're building the CFG from bottom to top, so when the return-value expression
has a non-trivial CFG on its own, we need to continue building from the entry
to the return-value expression CFG rather than from the block to which
we've just appended the return statement.

Fixes a false positive warning "control may reach end of non-void function".

llvm-svn: 370406
2019-08-29 20:37:28 +00:00