This patch introduces a specialized way to lower overflow-checked
multiplications with mixed-sign operands. This fixes link failures and
ICEs on code like this:
void mul(int64_t a, uint64_t b) {
int64_t res;
__builtin_mul_overflow(a, b, &res);
}
The generic checked-binop irgen would use a 65-bit multiplication
intrinsic here, which requires runtime support for _muloti4 (128-bit
multiplication), and therefore fails to link on i386. To get an ICE
on x86_64, change the example to use __int128_t / __uint128_t.
Adding runtime and backend support for 65-bit or 129-bit checked
multiplication on all of our supported targets is infeasible.
This patch solves the problem by using simpler, specialized irgen for
the mixed-sign case.
Testing: Apart from check-clang, I compared the output from this fairly
comprehensive test driver using unpatched & patched clangs:
https://gist.github.com/vedantk/3eb9c88f82e5c32f2e590555b4af5081
Erich Keane [Fri, 15 Dec 2017 16:37:14 +0000 (16:37 +0000)]
Remove "FunctionName -" from docs on FunctionDecl(NFC)
Removed the repetative usage of the operator name on the
documentation for FunctionDecl. Also reflowed some of the
comments since this changes the 80 character rule.
Erich Keane [Thu, 14 Dec 2017 23:37:08 +0000 (23:37 +0000)]
Correct UnaryTransformTypeLoc to properly initialize.
The initializeLocal function of UnaryTransformTypeLoc missed
the UnderlyingTInfo member. This caused a null-dereference
issue, as reported in PR23421. This patch correctly initializss
the UnderlyingTInfo.
Dimitry Andric [Thu, 14 Dec 2017 22:32:24 +0000 (22:32 +0000)]
Don't trigger -Wuser-defined-literals for system headers
Summary:
In D41064, I proposed adding `#pragma clang diagnostic ignored
"-Wuser-defined-literals"` to some of libc++'s headers, since these
warnings are now triggered by clang's new `-std=gnu++14` default:
```
$ cat test.cpp
#include <string>
$ clang -std=c++14 -Wsystem-headers -Wall -Wextra -c test.cpp
In file included from test.cpp:1:
In file included from /usr/include/c++/v1/string:470:
/usr/include/c++/v1/string_view:763:29: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string_view<char> operator "" sv(const char *__str, size_t __len)
^
/usr/include/c++/v1/string_view:769:32: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string_view<wchar_t> operator "" sv(const wchar_t *__str, size_t __len)
^
/usr/include/c++/v1/string_view:775:33: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string_view<char16_t> operator "" sv(const char16_t *__str, size_t __len)
^
/usr/include/c++/v1/string_view:781:33: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string_view<char32_t> operator "" sv(const char32_t *__str, size_t __len)
^
In file included from test.cpp:1:
/usr/include/c++/v1/string:4012:24: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string<char> operator "" s( const char *__str, size_t __len )
^
/usr/include/c++/v1/string:4018:27: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string<wchar_t> operator "" s( const wchar_t *__str, size_t __len )
^
/usr/include/c++/v1/string:4024:28: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string<char16_t> operator "" s( const char16_t *__str, size_t __len )
^
/usr/include/c++/v1/string:4030:28: warning: user-defined literal suffixes not starting with '_' are reserved [-Wuser-defined-literals]
basic_string<char32_t> operator "" s( const char32_t *__str, size_t __len )
^
8 warnings generated.
```
Both @aaron.ballman and @mclow.lists felt that adding this workaround to
the libc++ headers was the wrong way, and it should be fixed in clang
instead.
Here is a proposal to do just that. I verified that this suppresses the
warning, even when -Wsystem-headers is used, and that the warning is
still emitted for a declaration outside of system headers.
Yi Kong [Thu, 14 Dec 2017 22:24:45 +0000 (22:24 +0000)]
[ThreadSafetyAnalysis] Fix isCapabilityExpr
There are many more expr types that can be a capability expr, like
CXXThisExpr, CallExpr, MemberExpr. Instead of enumerating all of them,
just check typeHasCapability for any type given.
Also add & and * operators to allowed unary operators.
Aaron Ballman [Thu, 14 Dec 2017 22:17:09 +0000 (22:17 +0000)]
Harmonize GNU- and C++-style attribute spellings.
Most attributes will now use the Clang<"name"> construct to provide both __attribute__((name)) and [[clang::name]] syntaxes for the attribute. Attributes deviating from this should be marked with a comment explaining why they are not supported under both spellings. Common reasons are: the attribute is provided by some other specification that controls the syntax or the attribute cannot be exposed under a particular spelling for some given reason.
Because this is a mechanical change that only introduces new spellings, there are no test cases for the commit.
Don Hinton [Thu, 14 Dec 2017 22:12:46 +0000 (22:12 +0000)]
[debuginfo] Remove temporary FIXME.
Summary:
Now that r320495, "[debuginfo-tests] Support moving
debuginfo-tests to llvm/projects," has landed, remove temporary FIXME
that supported the old mechanism.
Zachary Turner [Thu, 14 Dec 2017 22:07:03 +0000 (22:07 +0000)]
Fix many -Wsign-compare and -Wtautological-constant-compare warnings.
Most of the -Wsign-compare warnings are due to the fact that
enums are signed by default in the MS ABI, while the
tautological comparison warnings trigger on x86 builds where
sizeof(size_t) is 4 bytes, so N > numeric_limits<unsigned>::max()
is always false.
This patch implements the __is_target_arch, __is_target_vendor, __is_target_os,
and __is_target_environment Clang preprocessor extensions that were proposed by
@compnerd in Bob's cfe-dev post:
http://lists.llvm.org/pipermail/cfe-dev/2017-November/056166.html.
These macros can be used to examine the components of the target triple at
compile time. A has_builtin(is_target_???) preprocessor check can be used to
check for their availability.
__is_target_arch allows you to check if an arch is specified without worring
about a specific subarch, e.g.
__is_target_arch(arm) returns 1 for the target arch "armv7"
__is_target_arch(armv7) returns 1 for the target arch "armv7"
__is_target_arch(armv6) returns 0 for the target arch "armv7"
__is_target_vendor and __is_target_environment match the specific vendor
or environment. __is_target_os matches the specific OS, but
__is_target_os(darwin) will match any Darwin-based OS. "Unknown" can be used
to test if the triple's component is specified.
Summary:
InterlockedCompareExchange128 is a bit more complicated than the other
InterlockedCompareExchange functions, so it requires a bit more work. It
doesn't directly refer to 128bit ints, instead it takes pointers to
64bit ints for Destination and ComparandResult, and exchange is taken as
two 64bit ints (high & low). The previous value is written to
ComparandResult, and success is returned. This implementation does the
following in order to produce a cmpxchg instruction:
1. Cast everything to 128bit ints or int pointers, and glues together
the Exchange values
2. Reads from CompareandResult to get the comparand
3. Calls cmpxchg volatile (on X86 this will produce a lock cmpxchg16b
instruction)
1. Result 0 (previous value) is written back to ComparandResult
2. Result 1 (success bool) is zext'ed to a uchar and returned
Richard Smith [Thu, 14 Dec 2017 15:40:16 +0000 (15:40 +0000)]
When attempting to complete an incomplete array bound type in an expression,
update the type from the definition even if we didn't instantiate a definition.
We may have instantiated the definition in an earlier stage of semantic
analysis, after creating the DeclRefExpr but before we reach a point where a
complete expression type is required.
Richard Smith [Thu, 14 Dec 2017 15:16:18 +0000 (15:16 +0000)]
[c++20] P0515R3: Parsing support and basic AST construction for operator <=>.
Adding the new enumerator forced a bunch more changes into this patch than I
would have liked. The -Wtautological-compare warning was extended to properly
check the new comparison operator, clang-format needed updating because it uses
precedence levels as weights for determining where to break lines (and several
operators increased their precedence levels with this change), thread-safety
analysis needed changes to build its own IL properly for the new operator.
All "real" semantic checking for this operator has been deferred to a future
patch. For now, we use the relational comparison rules and arbitrarily give
the builtin form of the operator a return type of 'void'.
Richard Smith [Thu, 14 Dec 2017 13:15:08 +0000 (13:15 +0000)]
Warn if we find a Unicode homoglyph for a symbol in an identifier.
Specifically, warn if:
* we find a character that the language standard says we must treat as an
identifier, and
* that character is not reasonably an identifier character (it's a punctuation
character or similar), and
* it renders identically to a valid non-identifier character in common
fixed-width fonts.
Some tools "helpfully" substitute the surprising characters for the expected
characters, and replacing semicolons with Greek question marks is a common
"prank".
IRGen: When performing CFI checks, load vtable pointer from vbase when necessary.
Under the Microsoft ABI, it is possible for an object not to have
a virtual table pointer of its own if all of its virtual functions
were introduced by virtual bases. In that case, we need to load the
vtable pointer from one of the virtual bases and perform the type
check using its type.
[OpenMP] Add function attribute for triggering data sharing.
Summary:
The backend should only emit data sharing code for the cases where it is needed.
A new function attribute is used by Clang to enable data sharing only for the cases where OpenMP semantics require it and there are variables that need to be shared.
Kelvin Li [Tue, 12 Dec 2017 20:08:12 +0000 (20:08 +0000)]
[OpenMP] Diagnose function name on the link clause
This patch is to add diagnose when a function name is
specified on the link clause. According to the OpenMP
spec, only the list items that exclude the function
name are allowed on the link clause.
Kelvin Li [Tue, 12 Dec 2017 18:33:39 +0000 (18:33 +0000)]
Add --cuda-path to mock a CUDA Toolkit installation to avoid
unexpected error messages for incompatibility between the
default SM level and the support in the installed toolkit.
Don Hinton [Tue, 12 Dec 2017 16:48:35 +0000 (16:48 +0000)]
[debuginfo-tests] Add support for moving debuginfo-tests from clang/test to llvm/projects or monorepo.
Summary:
The new version of debuginfo-tests will have it's own
lit.cfg.py file which is incompatible with the one in clang/test.
This change supports both the old and new versions, and can be used
until the bots actually move debuginfo-tests to either clang/test or
the monorepo.
Artem Dergachev [Tue, 12 Dec 2017 02:59:09 +0000 (02:59 +0000)]
[analyzer] StackAddrEscape: For now, disable the new async escape checks.
The new check introduced in r318705 is useful, but suffers from a particular
class of false positives, namely, it does not account for
dispatch_barrier_sync() API which allows one to ensure that the asyncronously
executed block that captures a pointer to a local variable does not actually
outlive that variable.
The new check is split into a separate checker, under the name of
alpha.core.StackAddressAsyncEscape, which is likely to get enabled by default
again once these positives are fixed. The rest of the StackAddressEscapeChecker
is still enabled by default.
Artem Dergachev [Tue, 12 Dec 2017 02:27:55 +0000 (02:27 +0000)]
[analyzer] In getSVal() API, disable auto-detection of void type as char type.
This is a follow-up from r314910. When a checker developer attempts to
dereference a location in memory through ProgramState::getSVal(Loc) or
ProgramState::getSVal(const MemRegion *), without specifying the second
optional QualType parameter for the type of the value he tries to find at this
location, the type is auto-detected from location type. If the location
represents a value beyond a void pointer, we thought that auto-detecting the
type as 'char' is a good idea. However, in most practical cases, the correct
behavior would be to specify the type explicitly, as it is available from other
sources, and the few cases where we actually need to take a 'char' are
workarounds rather than an intended behavior. Therefore, try to fail with an
easy-to-understand assertion when asked to read from a void pointer location.
Craig Topper [Mon, 11 Dec 2017 21:09:19 +0000 (21:09 +0000)]
[Driver][CodeGen] Add -mprefer-vector-width driver option and attribute during CodeGen.
This adds a new command line option -mprefer-vector-width to specify a preferred vector width for the vectorizers. Valid values are 'none' and unsigned integers. The driver will check that it meets those constraints. Specific supported integers will be managed by the targets in the backend.
Clang will take the value and add it as a new function attribute during CodeGen.
This represents the alternate direction proposed by Sanjay in this RFC: http://lists.llvm.org/pipermail/llvm-dev/2017-November/118734.html
The syntax here matches gcc, though gcc treats it as an x86 specific command line argument. gcc only allows values of 128, 256, and 512. I'm not having clang check any values.
Erich Keane [Mon, 11 Dec 2017 19:44:28 +0000 (19:44 +0000)]
PR35586: Relax two asserts that are overly restrictive
The two asserts are too aggressive. In C++ mode, an
enum is NOT considered an integral type, but an enum value
is allowed to be an enum. This patch relaxes the two asserts
to allow the enum value as well (as typechecking does).
Zhihao Yuan [Mon, 11 Dec 2017 18:29:54 +0000 (18:29 +0000)]
P0620 follow-up: deducing `auto` from braced-init-list in new expr
Summary:
This is a side-effect brought in by p0620r0, which allows other placeholder types (derived from `auto` and `decltype(auto)`) to be usable in a `new` expression with a single-clause //braced-init-list// as its initializer (8.3.4 [expr.new]/2). N3922 defined its semantics.
Malcolm Parsons [Mon, 11 Dec 2017 18:00:36 +0000 (18:00 +0000)]
[Sema] Fix crash in unused-lambda-capture warning for VLAs
Summary:
Clang was crashing when diagnosing an unused-lambda-capture for a VLA because
From.getVariable() is null for the capture of a VLA bound.
Warning about the VLA bound capture is not helpful, so only warn for the VLA
itself.
Alex Lorenz [Sat, 9 Dec 2017 02:27:11 +0000 (02:27 +0000)]
[driver][darwin] Refactor the target selection code, NFC
The simulator variant of Darwin's platforms is removed in favor of a new
environment field.
The code that selects the platform and the version is split into 4 different
functions instead of being all in one function.
This is an NFC commit, although it slightly improves the
"invalid version number" diagnostic by displaying the environment variable
instead of -m<os>-version-min if the OS version was derived from the
environment.
Akira Hatanaka [Sat, 9 Dec 2017 00:02:37 +0000 (00:02 +0000)]
[CodeGen][X86] Fix handling of __fp16 vectors.
This commit fixes a bug in IRGen where it generates completely broken
code for __fp16 vectors on X86. For example when the following code is
compiled:
half4 hv0, hv1, hv2; // these are vectors of __fp16.
void foo221() {
hv0 = hv1 + hv2;
}
clang generates the following IR, in which two i16 vectors are added:
@hv1 = common global <4 x i16> zeroinitializer, align 8
@hv2 = common global <4 x i16> zeroinitializer, align 8
@hv0 = common global <4 x i16> zeroinitializer, align 8
define void @foo221() {
%0 = load <4 x i16>, <4 x i16>* @hv1, align 8
%1 = load <4 x i16>, <4 x i16>* @hv2, align 8
%add = add <4 x i16> %0, %1
store <4 x i16> %add, <4 x i16>* @hv0, align 8
ret void
}
To fix the bug, this commit uses the code committed in r314056, which
modified clang to promote and truncate __fp16 vectors to and from float
vectors in the AST. It also fixes another IRGen bug where a short value
is assigned to an __fp16 variable without any integer-to-floating-point
conversion, as shown in the following example:
__fp16 a;
short b;
void foo1() {
a = b;
}
@b = common global i16 0, align 2
@a = common global i16 0, align 2
Richard Smith [Fri, 8 Dec 2017 22:57:11 +0000 (22:57 +0000)]
Unify implementation of our two different flavours of -Wtautological-compare,
and fold together into a single function.
In so doing, fix a handful of remaining bugs where we would report false
positives or false negatives if we promote a signed value to an unsigned type
for the comparison.
This re-commits r320122 and r320124, minus two changes:
* Comparisons between a constant and a non-constant expression of enumeration
type never warn, not even if the constant is out of range. We should be
warning about the creation of such a constant, not about its use.
* We do not use more precise bit-widths for comparisons against bit-fields.
The more precise diagnostics probably are the right thing, but we should
consider moving them under their own warning flag.
Other than the refactoring, this patch should only change the behavior for the
buggy cases (where the warnings didn't take into account that promotion from
signed to unsigned can leave a range of inaccessible values in the middle of
the promoted type).
Vedant Kumar [Fri, 8 Dec 2017 19:51:42 +0000 (19:51 +0000)]
[ubsan] array-bounds: Ignore params with constant size
This is a follow-up to r320128. Eli pointed out that there is some gray
area in the language standard about whether the constant size is exact,
or a lower bound.
Hans Wennborg [Fri, 8 Dec 2017 16:54:08 +0000 (16:54 +0000)]
Revert "Unify implementation of our two different flavours of -Wtautological-compare."
> Unify implementation of our two different flavours of -Wtautological-compare.
>
> In so doing, fix a handful of remaining bugs where we would report false
> positives or false negatives if we promote a signed value to an unsigned type
> for the comparison.
This caused a new warning in Chromium:
../../base/trace_event/trace_log.cc:1545:29: error: comparison of constant 64
with expression of type 'unsigned int' is always true
[-Werror,-Wtautological-constant-out-of-range-compare]
DCHECK(handle.event_index < TraceBufferChunk::kTraceBufferChunkSize);
~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The 'unsigned int' is really a 6-bit bitfield, which is why it's always
less than 64.
I thought we didn't use to warn (with out-of-range-compare) when comparing
against the boundaries of a type?
In stdbool.h, define bool, false, true only in gnu++98
GCC has meanwhile corrected that with the similar
<https://gcc.gnu.org/viewcvs/gcc?view=revision&revision=216679> "C++11
explicitly forbids macros for bool, true and false."
Hans Wennborg [Fri, 8 Dec 2017 05:19:12 +0000 (05:19 +0000)]
Revert r320124 "Fold together the in-range and out-of-range portions of -Wtautological-compare."
This broke Chromium:
../../base/trace_event/trace_log.cc:1545:29: error: comparison of constant 64
with expression of type 'unsigned int' is always true
[-Werror,-Wtautological-constant-out-of-range-compare]
DCHECK(handle.event_index < TraceBufferChunk::kTraceBufferChunkSize);
~~~~~~~~~~~~~~~~~~ ^ ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
The 'unsigned int' is really a 6-bit bitfield, which is why it's always
less than 63.
Did this use to fall under the "in-range" case before? I thought we
didn't use to warn when comparing against the boundaries of a type.
Richard Smith [Fri, 8 Dec 2017 00:45:25 +0000 (00:45 +0000)]
Unify implementation of our two different flavours of -Wtautological-compare.
In so doing, fix a handful of remaining bugs where we would report false
positives or false negatives if we promote a signed value to an unsigned type
for the comparison.
Aaron Ballman [Thu, 7 Dec 2017 21:46:26 +0000 (21:46 +0000)]
Add new language mode flags for C17.
This adds -std=c17, -std=gnu17, and -std=iso9899:2017 as language mode flags for C17 and updates the value of __STDC_VERSION__ to the value based on the C17 FDIS. Given that this ballot cannot succeed until 2018, it is expected that we (and GCC) will add c18 flags as aliases once the ballot passes.
Aaron Ballman [Thu, 7 Dec 2017 21:37:49 +0000 (21:37 +0000)]
Add support for the __has_c_attribute builtin preprocessor macro.
This behaves similar to the __has_cpp_attribute builtin macro in that it allows users to detect whether an attribute is supported with the [[]] spelling syntax, which can be enabled in C with -fdouble-square-bracket-attributes.
George Rokos [Thu, 7 Dec 2017 20:27:31 +0000 (20:27 +0000)]
[OpenMP] NVPTX: Set default/minimum compute capability to sm_35
The current implementation of the nvptx runtime (to be upstreamed shortly) uses the atomicMax operation on 64-bit integers.
This is only supported in compute capabilities 3.5 and later. I've changed the clang default to sm_35.
Alexey Bataev [Thu, 7 Dec 2017 19:49:28 +0000 (19:49 +0000)]
[OPENMP] Do not capture private variables in the target regions.
Private variables are completely redefined in the outlined regions, so
we don't need to capture them. Patch adds this behavior to the
target-based regions.
Sjoerd Meijer [Thu, 7 Dec 2017 09:54:39 +0000 (09:54 +0000)]
[ARM] ACLE parallel arithmetic and DSP style multiplications
This is a follow up of r302131, in which we forgot to add SemaChecking
tests. Adding these tests revealed two problems which have been fixed:
- added missing intrinsic __qdbl,
- properly range checking ssat16 and usat16.
projects / clang / log