Commit Graph

3220 Commits

Author SHA1 Message Date
Aaron Ballman 3b70e75780 Disallow a cleanup attribute from appertaining to a parameter (the attribute only appertains to local variables and is silently a noop on parameters). This repurposes the unused (and syntactically incorrect) NormalVar attribute subject.
llvm-svn: 319555
2017-12-01 16:53:49 +00:00
Aaron Ballman cfc1485f86 Remove duplicate, nonsense information from an attribute diagnostic. The NonParmVar subject does not need to mention functions, and the resulting diagnostic definitely does not need to mention functions twice.
llvm-svn: 319549
2017-12-01 15:54:29 +00:00
Aaron Ballman d1f6dcd1f5 Perform a bounds check on a function's argument list before accessing any index value specified by an 'argument_with_type_tag' attribute. Fixes PR28520.
Patch by Matt Davis.

llvm-svn: 319383
2017-11-29 23:10:14 +00:00
Aaron Ballman adf66b6174 Determine the attribute subject for diagnostics based on declarative information in DeclNodes.td. This greatly reduces the number of enumerated values used for more complex diagnostics; these are now only required when the "attribute only applies to" diagnostic needs to be generated manually as part of semantic processing.
This also clarifies some terminology used by the diagnostic (methods -> Objective-C methods, fields -> non-static data members, etc).

Many of the tests needed to be updated in multiple places for the diagnostic wording tweaks. The first instance of the diagnostic for that attribute is fully specified and subsequent instances cut off the complete list (to make it easier if additional subjects are added in the future for the attribute).

llvm-svn: 319002
2017-11-26 20:01:12 +00:00
Richard Smith efdb50375f PR35214: don't crash if we see an array of unknown bound added to an empty but invalid designator.
llvm-svn: 318258
2017-11-15 03:03:56 +00:00
Alex Lorenz 4e30b96834 Clarify the error message for unsupported aliases on Darwin
rdar://35109556

llvm-svn: 317532
2017-11-07 00:31:19 +00:00
Roman Lebedev d9af8e1f98 [Sema] Document+test the -Wsign-conversion change for enums in C code [NFC]
Basically a regression after r316268.
However the diagnostic is correct, but the test coverage is bad.

So just like rL316500, introduce yet more tests,
and adjust the release notes.

See https://bugs.llvm.org/show_bug.cgi?id=35200

llvm-svn: 317421
2017-11-04 20:27:47 +00:00
Roman Lebedev 7ade0173df [Sema] Document+test the -Wsign-compare change for enums in C code [NFC]
rL316268 / D39122 has fixed PR35009, and now when in C,
these three(?) diagnostics properly use the enum's underlying
datatype.

While it was fixed, the test coverage was clearly insufficient,
because the -Wsign-compare change didn't show up in any of the
tests, until it was reported in the post-commit mail for rL316268.

So add the test for the -Wsign-compare diagnostic for enum
for C code, and while there, document this in the release notes.

The fix itself was obviously correct, so unless we want to silence
this new diagnosed case, i deem this commit to be NFC.

llvm-svn: 316500
2017-10-24 21:05:43 +00:00
Volodymyr Sapsai 30680e9437 [Sema] Add support for flexible array members in Obj-C.
Allow Obj-C ivars with incomplete array type but only as the last ivar.
Also add a requirement for ivars that contain a flexible array member to
be at the end of class too. It is possible to add in a subclass another
ivar at the end but we'll emit a warning in this case. Also we'll emit a
warning if a variable sized ivar is declared in class extension or in
implementation because subclasses won't know they should avoid adding
new ivars.

In ARC incomplete array objects are treated as __unsafe_unretained so
require them to be marked as such.

Prohibit synthesizing ivars with flexible array members because order of
synthesized ivars is not obvious and tricky to control. Spelling out
ivar explicitly gives control to developers and helps to avoid surprises
with unexpected ivar ordering.

For C and C++ changed diagnostic to tell explicitly a field is not the
last one and point to the next field. It is not as useful as in Obj-C
but it is an improvement and it is consistent with Obj-C. For C for
unions emit more specific err_flexible_array_union instead of generic
err_field_incomplete.

rdar://problem/21054495

Reviewers: rjmccall, theraven

Reviewed By: rjmccall

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D38773

llvm-svn: 316381
2017-10-23 22:01:41 +00:00
Roman Lebedev ca1aaacc32 [Sema] Fixes for enum handling for tautological comparison diagnostics
Summary:
As Mattias Eriksson has reported in PR35009, in C, for enums, the underlying type should
be used when checking for the tautological comparison, unlike C++, where the enumerator
values define the value range. So if not in CPlusPlus mode, use the enum underlying type.

Also, i have discovered a problem (a crash) when evaluating tautological-ness of the following comparison:
```
enum A { A_a = 0 };
if (a < 0) // expected-warning {{comparison of unsigned enum expression < 0 is always false}}
return 0;
```
This affects both the C and C++, but after the first fix, only C++ code was affected.
That was also fixed, while preserving (i think?) the proper diagnostic output.

And while there, attempt to enhance the test coverage.
Yes, some tests got moved around, sorry about that :)

Fixes PR35009

Reviewers: aaron.ballman, rsmith, rjmccall

Reviewed By: aaron.ballman

Subscribers: Rakete1111, efriedma, materi, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D39122

llvm-svn: 316268
2017-10-21 16:44:03 +00:00
Aaron Ballman 15d267bb75 Enable support for the [[maybe_unused]] attribute from WG14 N2053 when enabling double square bracket attributes in C code.
llvm-svn: 316096
2017-10-18 16:59:27 +00:00
Aaron Ballman 8eab4e5856 Silencing a redefinition warning that was not germane to the test.
llvm-svn: 316086
2017-10-18 14:48:33 +00:00
Aaron Ballman 8c6b1a3bf2 Enable support for the [[fallthrough]] attribute from WG14 N2052 when enabling double square bracket attributes in C code.
llvm-svn: 316083
2017-10-18 14:33:27 +00:00
Nico Weber 3dc67a1d8a Fix PR34981, a crash-on-invalid merging dllimport to an invalid redecl.
This is basically like r288207, just the other way round.

llvm-svn: 316032
2017-10-17 21:14:02 +00:00
Aaron Ballman 35713eba56 Enable support for the [[nodiscard]] attribute from WG14 N2050 when enabling double square bracket attributes in C code.
llvm-svn: 316026
2017-10-17 20:33:35 +00:00
Bruno Cardoso Lopes 9e5751894d [OpenCL] Restrict swizzle length check to OpenCL mode
Changes behavior introduced in r298369 to only error out on
vector component invalid length access on OpenCL mode.

Differential Revision: https://reviews.llvm.org/D38868

rdar://problem/33568748

llvm-svn: 316016
2017-10-17 17:54:57 +00:00
Roman Lebedev 6de129e710 [Sema] Re-land: Diagnose tautological comparison with type's min/max values
The first attempt, rL315614 was reverted because one libcxx
test broke, and i did not know at the time how to deal with it.

Summary:
Currently, clang only diagnoses completely out-of-range comparisons (e.g. `char` and constant `300`),
and comparisons of unsigned and `0`. But gcc also does diagnose the comparisons with the
`std::numeric_limits<>::max()` / `std::numeric_limits<>::min()` so to speak

Finally Fixes https://bugs.llvm.org/show_bug.cgi?id=34147
Continuation of https://reviews.llvm.org/D37565

Reviewers: rjmccall, rsmith, aaron.ballman

Reviewed By: rsmith

Subscribers: rtrieu, jroelofs, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D38101

llvm-svn: 315875
2017-10-15 20:13:17 +00:00
Aaron Ballman 606093a53b Add -f[no-]double-square-bracket-attributes as new driver options to control use of [[]] attributes in all language modes. This is the initial implementation of WG14 N2165, which is a proposal to add [[]] attributes to C2x, but also allows you to enable these attributes in C++98, or disable them in C++11 or later.
llvm-svn: 315856
2017-10-15 15:01:42 +00:00
Roman Lebedev 6f405dbe5c Revert "[Sema] Diagnose tautological comparison with type's min/max values"
This reverts r315614,r315615,r315621,r315622
Breaks http://bb9.pgr.jp/#/builders/20/builds/59

/home/bb9/bootstrap-clang-libcxx-lld-i686-linux/llvm-project/libcxx/test/std/experimental/filesystem/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp:95:17: error: comparison 'long long' > 9223372036854775807 is always false [-Werror,-Wtautological-constant-compare]
    if (max_sec > Lim::max()) return false;
        ~~~~~~~ ^ ~~~~~~~~~~
/home/bb9/bootstrap-clang-libcxx-lld-i686-linux/llvm-project/libcxx/test/std/experimental/filesystem/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp:124:13: error: comparison 'long long' < -9223372036854775808 is always false [-Werror,-Wtautological-constant-compare]
    if (sec < Lim::min() || sec > Lim::max())   return false;
        ~~~ ^ ~~~~~~~~~~
/home/bb9/bootstrap-clang-libcxx-lld-i686-linux/llvm-project/libcxx/test/std/experimental/filesystem/fs.op.funcs/fs.op.last_write_time/last_write_time.pass.cpp:124:33: error: comparison 'long long' > 9223372036854775807 is always false [-Werror,-Wtautological-constant-compare]
    if (sec < Lim::min() || sec > Lim::max())   return false;
                            ~~~ ^ ~~~~~~~~~~
3 errors generated.
--

I'm not yet sure what is the proper fix.

llvm-svn: 315631
2017-10-12 22:03:20 +00:00
Roman Lebedev bd1fc22043 [Sema] Diagnose tautological comparison with type's min/max values
Summary:
Currently, clang only diagnoses completely out-of-range comparisons (e.g. `char` and constant `300`),
and comparisons of unsigned and `0`. But gcc also does diagnose the comparisons with the
`std::numeric_limits<>::max()` / `std::numeric_limits<>::min()` so to speak

Finally Fixes https://bugs.llvm.org/show_bug.cgi?id=34147
Continuation of https://reviews.llvm.org/D37565

Reviewers: rjmccall, rsmith, aaron.ballman

Reviewed By: rsmith

Subscribers: rtrieu, jroelofs, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D38101

llvm-svn: 315614
2017-10-12 20:16:51 +00:00
Saleem Abdulrasool 729379a1e1 Driver: hoist the `wchar_t` handling to the driver
Move the logic for determining the `wchar_t` type information into the
driver.  Rather than passing the single bit of information of
`-fshort-wchar` indicate to the frontend the desired type of `wchar_t`
through a new `-cc1` option of `-fwchar-type` and indicate the
signedness through `-f{,no-}signed-wchar`.  This replicates the current
logic which was spread throughout Basic into the
`RenderCharacterOptions`.

Most of the changes to the tests are to ensure that the frontend uses
the correct type.  Add a new test set under `test/Driver/wchar_t.c` to
ensure that we calculate the proper types for the various cases.

llvm-svn: 315126
2017-10-06 23:09:55 +00:00
Alex Lorenz e9baea8178 -Wdocumentation should allow '...' params in variadic function type aliases
rdar://34811344

llvm-svn: 315103
2017-10-06 20:51:04 +00:00
Erich Keane 95be5d2e49 Fix 'section' warning behavior with tentatively-defined values
As reported on cfe-commits, r314262 resulted in tentatively-defined
variables not being excluded for the warning.

Patch By: Elizabeth Andrews

llvm-svn: 314939
2017-10-04 22:16:24 +00:00
Richard Smith 9bfa970a40 PR34822: Fix a collection of related bugs with our handling of C89 implicit function declarations.
We were injecting the function into the wrong semantic context, resulting in it
failing to be registered as a global for redeclaration lookup. As a
consequence, we accepted invalid code since r310616.

Fixing that resulted in the "out-of-scope declaration" diagnostic firing a lot
more often. It turned out that warning codepath was non-conforming, because it
did not cause us to inject the implicitly-declared function into the enclosing
block scope. We now only warn if the type of the out-of-scope declaration
doesn't match the type of an implicitly-declared function; in all other cases,
we produce the normal warning for an implicitly-declared function.

llvm-svn: 314871
2017-10-04 01:49:22 +00:00
Richard Smith 283e2076f6 Suppress -Wmissing-braces warning when aggregate-initializing a struct with a single field that is itself an aggregate.
In C++, such initialization of std::array<T, N> types is guaranteed to work by
the standard, is completely idiomatic, and the "suggested" alternative from
Clang was technically invalid.

llvm-svn: 314838
2017-10-03 20:36:00 +00:00
Daniel Marjamaki 817a3bfcdd [Sema] Suppress warnings for C's zero initializer
Patch by S. Gilles!

Differential Revision: https://reviews.llvm.org/D28148

llvm-svn: 314499
2017-09-29 09:44:41 +00:00
Alexander Shaposhnikov 195b25cf3c [clang] Add getUnsignedPointerDiffType method
C11 standard refers to the unsigned counterpart of the type ptrdiff_t 
in the paragraph 7.21.6.1p7 where it defines the format specifier %tu.
In Clang (in PrintfFormatString.cpp, lines 508-510) there is a FIXME for this case,
in particular, Clang didn't diagnose %tu issues at all, i.e.
it didn't emit any warnings on the code printf("%tu", 3.14).
In this diff we add a method getUnsignedPointerDiffType for getting the corresponding type
similarly to how it's already done in the other analogous cases (size_t, ssize_t, ptrdiff_t etc)
and fix -Wformat diagnostics for %tu plus the emitted fix-it as well.

Test plan: make check-all

Differential revision: https://reviews.llvm.org/D38270

llvm-svn: 314470
2017-09-28 23:11:31 +00:00
Yaxun Liu 304f349770 [AMDGPU] Allow flexible register names in inline asm constraints
Currently AMDGPU inline asm only allow v and s as register names in constraints.

This patch allows the following register names in constraints: (n, m is unsigned integer, n < m)

v

s

{vn} or {v[n]}

{sn} or {s[n]}

{S} , where S is a special register name

{v[n:m]}

{s[n:m]}

Differential Revision: https://reviews.llvm.org/D37568

llvm-svn: 314452
2017-09-28 19:07:59 +00:00
Erich Keane 99fdfb6a46 Emit section information for extern variables.
Currently, if _attribute_((section())) is used for extern variables, 
section information is not emitted in generated IR when the variables are used. 
This is expected since sections are not generated for external linkage objects. 
However NiosII requires this information as it uses special GP-relative accesses 
for any objects that use attribute section (.sdata). GCC keeps this attribute in 
  middle-end.

This change emits the section information for all targets.

Patch By: Elizabeth Andrews

Differential Revision:https://reviews.llvm.org/D36487

llvm-svn: 314262
2017-09-26 23:42:34 +00:00
Saleem Abdulrasool 4d321336d0 Basic: support Preserve{Most,All} CC on Windows
Add support for the `preserve_mostcc` and `preserve_allcc` on Windows
x86_64 and AArch64.  This is used by Swift.

llvm-svn: 314236
2017-09-26 19:26:01 +00:00
Akira Hatanaka 34b5dbca0a Promote storage-only __fp16 vector operands to float vectors.
This commit fixes a bug in the handling of storage-only __fp16 vectors
where clang didn't promote __fp16 vector operands to float vectors.

Conceptually, it performs the following transformation on the AST in
CreateBuiltinBinOp and CreateBuiltinUnaryOp:

(Before)
  typedef __fp16 half4 __attribute__ ((vector_size (8)));
  typedef float float4 __attribute__ ((vector_size (16)));
  half4 hv0, hv1, hv2, hv3;

  hv0 = hv1 + hv2 + hv3;

(After)
  float4 t0 = (float4)hv1 + (float4)hv2;
  float4 t1 = t0 + (float4)hv3;
  hv0 = (half4)t1;

Note that this commit fixes the bug for targets that set
HalfArgsAndReturns to true (ARM and ARM64). Targets using intrinsics
such as llvm.convert.to.fp16 to handle __fp16 are still broken.

rdar://problem/20625184

Differential Revision: https://reviews.llvm.org/D32520

llvm-svn: 314056
2017-09-23 05:02:02 +00:00
Akira Hatanaka 6c2dbc69a7 Add test cases that weren't committed in r313945.
llvm-svn: 313952
2017-09-22 01:54:36 +00:00
Volodymyr Sapsai 8c9fde598b [fixup][Sema] Allow in C to define tags inside enumerations.
Fix for too aggressive error err_type_defined_in_enum introduced in
r313386. Defining tags inside enumerations is prohibited in C++ but
allowed in C.

Reviewers: aaron.ballman, rnk, doug.gregor

Reviewed By: rnk

Subscribers: alberto_magni, cfe-commits

Differential Revision: https://reviews.llvm.org/D38109

llvm-svn: 313894
2017-09-21 17:41:30 +00:00
Andrew Kaylor b9be53634c Remove offset size check in nullptr arithmetic handling
Differential Revision: https://reviews.llvm.org/D37042

llvm-svn: 313784
2017-09-20 18:06:44 +00:00
Roman Lebedev 30d2608637 Replace r313747, don't always warn on enums, rework testcases.
As Aaron Ballman has pointed out, that is not really correct.
So the key problem there is the invalidity of the testcase.

Revert r313747, and rework testcase in such a way, so these
details (platform-specific default enum sigdness) are
accounted for.

Also, add a C++-specific testcase.

llvm-svn: 313756
2017-09-20 13:50:01 +00:00
Roman Lebedev b0f0a1ea03 [Sema] Move some stuff into -Wtautological-unsigned-enum-zero-compare
Recommit. Original commit was reverted because buildbots broke.
The error was only reproducible in the build with assertions.
The problem was that the diagnostic expected true/false as
bool, while it was provided as string "true"/"false".

Summary:
As requested by Sam McCall:
> Enums (not new I guess). Typical case: if (enum < 0 || enum > MAX)
> The warning strongly suggests that the enum < 0 check has no effect
> (for enums with nonnegative ranges).
> Clang doesn't seem to optimize such checks out though, and they seem
> likely to catch bugs in some cases. Yes, only if there's UB elsewhere,
> but I assume not optimizing out these checks indicates a deliberate
> decision to stay somewhat compatible with a technically-incorrect
> mental model.
> If this is the case, should we move these to a
> -Wtautological-compare-enum subcategory?

Reviewers: rjmccall, rsmith, aaron.ballman, sammccall, bkramer, djasper

Reviewed By: aaron.ballman

Subscribers: jroelofs, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D37629

llvm-svn: 313745
2017-09-20 09:54:47 +00:00
Akira Hatanaka 30c93dba5b Revert "Add support for attribute 'noescape'."
This reverts commit r313722.

It looks like compiler-rt/lib/tsan/rtl/tsan_libdispatch_mac.cc cannot be
compiled because some of the functions declared in the file do not match
the ones in the SDK headers (which are annotated with 'noescape').

llvm-svn: 313725
2017-09-20 06:55:43 +00:00
Akira Hatanaka e974479fa5 Add support for attribute 'noescape'.
The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.

rdar://problem/19886775

Differential Revision: https://reviews.llvm.org/D32210

llvm-svn: 313722
2017-09-20 06:32:45 +00:00
Akira Hatanaka 1b9418e163 Revert "Add support for attribute 'noescape'."
This reverts r313717.

I closed the wrong phabricator review.

llvm-svn: 313721
2017-09-20 06:27:39 +00:00
Akira Hatanaka fc587e6a57 Add support for attribute 'noescape'.
The attribute informs the compiler that the annotated pointer parameter
of a function cannot escape and enables IRGen to attach attribute
'nocapture' to parameters that are annotated with the attribute. That is
the only optimization that currently takes advantage of 'noescape', but
there are other optimizations that will be added later that improves
IRGen for ObjC blocks.

rdar://problem/19886775

Differential Revision: https://reviews.llvm.org/D32520

llvm-svn: 313720
2017-09-20 06:22:51 +00:00
Andrew Kaylor 21a2aa7203 Fix 32-bit buildbots by removing tests that are dependent on pointer-size comparisons.
The recently behavior in the code that these tests were meant to be checking will be ammended as soon as a suitable change can be properly reviewed.

llvm-svn: 313684
2017-09-19 21:43:01 +00:00
Roman Lebedev 918eaf9585 Revert "[Sema] Move some stuff into -Wtautological-unsigned-enum-zero-compare"
This reverts commit r313677.

Buildbots fail with assertion failure
Failing Tests (7):
    Clang :: Analysis/null-deref-ps.c
    Clang :: CodeGen/enum.c
    Clang :: Sema/compare.c
    Clang :: Sema/outof-range-constant-compare.c
    Clang :: Sema/tautological-unsigned-enum-zero-compare.c
    Clang :: Sema/tautological-unsigned-zero-compare.c
    Clang :: SemaCXX/compare.cpp

llvm-svn: 313683
2017-09-19 21:40:41 +00:00
Roman Lebedev c9c9748d99 [Sema] Move some stuff into -Wtautological-unsigned-enum-zero-compare
Summary:
As requested by Sam McCall:
> Enums (not new I guess). Typical case: if (enum < 0 || enum > MAX)
> The warning strongly suggests that the enum < 0 check has no effect
> (for enums with nonnegative ranges).
> Clang doesn't seem to optimize such checks out though, and they seem
> likely to catch bugs in some cases. Yes, only if there's UB elsewhere,
> but I assume not optimizing out these checks indicates a deliberate
> decision to stay somewhat compatible with a technically-incorrect
> mental model.
> If this is the case, should we move these to a
> -Wtautological-compare-enum subcategory?

Reviewers: rjmccall, rsmith, aaron.ballman, sammccall, bkramer, djasper

Reviewed By: aaron.ballman

Subscribers: jroelofs, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D37629

llvm-svn: 313677
2017-09-19 21:11:35 +00:00
Andrew Kaylor 3d0a540857 Teach clang to tolerate the 'p = nullptr + n' idiom used by glibc
Differential Revision: https://reviews.llvm.org/D37042

llvm-svn: 313666
2017-09-19 20:26:40 +00:00
Bjorn Pettersson 9cf0e12a80 [Sema] Disallow assigning record lvalues with nested const-qualified fields.
Summary:
According to C99 6.3.2.1p1, structs and unions with nested
const-qualified fields (that is, const-qualified fields
declared at some recursive level of the aggregate) are not
modifiable lvalues. However, Clang permits assignments of
these lvalues.

With this patch, we both prohibit the assignment of records
with const-qualified fields and emit a best-effort diagnostic.
This fixes https://bugs.llvm.org/show_bug.cgi?id=31796 .

Committing on behalf of bevinh (Bevin Hansson).

Reviewers: rtrieu, rsmith, bjope

Reviewed By: bjope

Subscribers: Ka-Ka, rogfer01, bjope, fhahn, cfe-commits

Differential Revision: https://reviews.llvm.org/D37254

llvm-svn: 313628
2017-09-19 13:10:30 +00:00
Volodymyr Sapsai 8b0bbc6fe0 [Sema] Error out early for tags defined inside an enumeration.
This fixes PR28903 by avoiding access check for inner enum constant. We
are performing access check because one enum constant references another
and because enum is defined in CXXRecordDecl. But access check doesn't
work because FindDeclaringClass doesn't expect more than one EnumDecl
and because inner enum has access AS_none due to not being an immediate
child of a record.

The change detects an enum is defined in wrong place and allows to skip
parsing its body. Access check is skipped together with body parsing.
There was no crash in C, added test case to cover the new error.

rdar://problem/28530809

Reviewers: rnk, doug.gregor, rsmith

Reviewed By: doug.gregor

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D37089

llvm-svn: 313386
2017-09-15 19:51:42 +00:00
Piotr Padlewski 45761a6950 Enable __declspec(selectany) on any platform
Summary:
This feature was disabled probably by mistake in rL300562
This fixes bug https://bugs.llvm.org/show_bug.cgi?id=33285

Reviewers: davide, rnk

Subscribers: cfe-commits

Differential Revision: https://reviews.llvm.org/D33852

llvm-svn: 313278
2017-09-14 17:33:08 +00:00
Roman Lebedev 309b7f5d77 [Sema] Put tautological comparison of unsigned and zero into it's own flag
Summary:
As requested by Sam McCall.

```
$ /build/llvm-build-Clang-release/./bin/clang -c /build/clang/test/Sema/outof-range-constant-compare.c /build/clang/test/Sema/outof-range-constant-compare.c:40:11: warning: comparison of unsigned expression < 0 is always false [-Wtautological-unsigned-zero-compare]
    if (a < 0x0000000000000000UL) // expected-warning {{comparison of unsigned expression < 0 is always false}}
        ~ ^ ~~~~~~~~~~~~~~~~~~~~
```

Reviewers: sammccall, bkramer, djasper, rsmith, rjmccall, aaron.ballman

Reviewed By: sammccall, aaron.ballman

Subscribers: aaron.ballman, cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D37620

llvm-svn: 312792
2017-09-08 13:56:45 +00:00
Roman Lebedev 6aa34aadd1 [Sema] -Wtautological-compare: handle comparison of unsigned with 0S.
Summary:
This is a first half(?) of a fix for the following bug:
https://bugs.llvm.org/show_bug.cgi?id=34147 (gcc -Wtype-limits)

GCC's -Wtype-limits does warn on comparison of unsigned value
with signed zero (as in, with 0), but clang only warns if the
zero is unsigned (i.e. 0U).

Also, be careful not to double-warn, or falsely warn on
comparison of signed/fp variable and signed 0.

Yes, all these testcases are needed.

Testing: $ ninja check-clang-sema check-clang-semacxx
Also, no new warnings for clang stage-2 build.

Reviewers: rjmccall, rsmith, aaron.ballman

Reviewed By: rjmccall

Subscribers: cfe-commits

Tags: #clang

Differential Revision: https://reviews.llvm.org/D37565

llvm-svn: 312750
2017-09-07 22:14:25 +00:00
Reid Kleckner 30701edf76 [ms] Implement the __annotation intrinsic
llvm-svn: 312572
2017-09-05 20:27:35 +00:00