Summary:
This attribute allows excluding a member of a class template from being part
of an explicit template instantiation of that class template. This also makes
sure that code using such a member will not take for granted that an external
instantiation exists in another translation unit. The attribute was discussed
on cfe-dev at [1] and is primarily motivated by the removal of always_inline
in libc++ to control what's part of the ABI (see links in [1]).
[1]: http://lists.llvm.org/pipermail/cfe-dev/2018-August/059024.html
rdar://problem/43428125
Reviewers: rsmith
Subscribers: dexonsmith, cfe-commits
Differential Revision: https://reviews.llvm.org/D51789
llvm-svn: 343790
Currently, attributes from previous declarations ('inherited attributes')
are added to the end of a declaration's list of attributes. Before
r338800, the attribute list was in reverse. r338800 changed the order
of non-inherited (parsed from the current declaration) attributes, but
inherited attributes are still appended to the end of the list.
This patch appends inherited attributes after other inherited
attributes, but before any non-inherited attribute. This is to make the
order of attributes in the AST correspond to the order in the source
code.
Differential Revision: https://reviews.llvm.org/D50214
llvm-svn: 342861
Summary:
We previously disallowed use of undocumented attributes with #pragma clang
attribute, but the justification for doing so was weak and it prevented many
reasonable use cases.
Reviewers: aaron.ballman, arphaman
Subscribers: cfe-commits, rnk, benlangmuir, dexonsmith, erik.pilkington
Differential Revision: https://reviews.llvm.org/D51507
llvm-svn: 341437
This commit adds the flag -fno-c++-static-destructors and the attributes
[[clang::no_destroy]] and [[clang::always_destroy]]. no_destroy specifies that a
specific static or thread duration variable shouldn't have it's destructor
registered, and is the default in -fno-c++-static-destructors mode.
always_destroy is the opposite, and is the default in -fc++-static-destructors
mode.
A variable whose destructor is disabled (either because of
-fno-c++-static-destructors or [[clang::no_destroy]]) doesn't count as a use of
the destructor, so we don't do any access checking or mark it referenced. We
also don't emit -Wexit-time-destructors for these variables.
rdar://21734598
Differential revision: https://reviews.llvm.org/D50994
llvm-svn: 340306
Recommit of r335084 after revert in r335516.
... instead of prepending it at the beginning (the original behavior
since implemented in r122535 2010-12-23). This builds up an
AttributeList in the the order in which the attributes appear in the
source.
The reverse order caused nodes for attributes in the AST (e.g. LoopHint)
to be in the reverse order, and therefore printed in the wrong order in
-ast-dump. Some TODO comments mention this. The order was explicitly
reversed for enable_if attribute overload resolution and name mangling,
which is not necessary anymore with this patch.
The change unfortunately has some secondary effect, especially on
diagnostic output. In the simplest cases, the CHECK lines or expected
diagnostic were changed to the the new output. If the kind of
error/warning changed, the attributes' order was changed instead.
This unfortunately causes some 'previous occurrence here' hints to be
textually after the main marker. This typically happens when attributes
are merged, but are incompatible to each other. Interchanging the role
of the the main and note SourceLocation will also cause the case where
two different declaration's attributes (in contrast to multiple
attributes of the same declaration) are merged to be reverse. There is
no easy fix because sometimes previous attributes are merged into a new
declaration's attribute list, sometimes new attributes are added to a
previous declaration's attribute list. Since 'previous occurrence here'
pointing to locations after the main marker is not rare, I left the
markers as-is; it is only relevant when the attributes are declared in
the same declaration anyway.
Differential Revision: https://reviews.llvm.org/D48100
llvm-svn: 338800
As documented here: https://software.intel.com/en-us/node/682969 and
https://software.intel.com/en-us/node/523346. cpu_dispatch multiversioning
is an ICC feature that provides for function multiversioning.
This feature is implemented with two attributes: First, cpu_specific,
which specifies the individual function versions. Second, cpu_dispatch,
which specifies the location of the resolver function and the list of
resolvable functions.
This is valuable since it provides a mechanism where the resolver's TU
can be specified in one location, and the individual implementions
each in their own translation units.
The goal of this patch is to be source-compatible with ICC, so this
implementation diverges from the ICC implementation in a few ways:
1- Linux x86/64 only: This implementation uses ifuncs in order to
properly dispatch functions. This is is a valuable performance benefit
over the ICC implementation. A future patch will be provided to enable
this feature on Windows, but it will obviously more closely fit ICC's
implementation.
2- CPU Identification functions: ICC uses a set of custom functions to identify
the feature list of the host processor. This patch uses the cpu_supports
functionality in order to better align with 'target' multiversioning.
1- cpu_dispatch function def/decl: ICC's cpu_dispatch requires that the function
marked cpu_dispatch be an empty definition. This patch supports that as well,
however declarations are also permitted, since the linker will solve the
issue of multiple emissions.
Differential Revision: https://reviews.llvm.org/D47474
llvm-svn: 337552
This is part of an ongoing attempt at making 512 bit vectors illegal in the X86 backend type legalizer due to CPU frequency penalties associated with wide vectors on Skylake Server CPUs. We want the loop vectorizer to be able to emit IR containing wide vectors as intermediate operations in vectorized code and allow these wide vectors to be legalized to 256 bits by the X86 backend even though we are targetting a CPU that supports 512 bit vectors. This is similar to what happens with an AVX2 CPU, the vectorizer can emit wide vectors and the backend will split them. We want this splitting behavior, but still be able to use new Skylake instructions that work on 256-bit vectors and support things like masking and gather/scatter.
Of course if the user uses explicit vector code in their source code we need to not split those operations. Especially if they have used any of the 512-bit vector intrinsics from immintrin.h. And we need to make it so that merely using the intrinsics produces the expected code in order to be backwards compatible.
To support this goal, this patch adds a new IR function attribute "min-legal-vector-width" that can indicate the need for a minimum vector width to be legal in the backend. We need to ensure this attribute is set to the largest vector width needed by any intrinsics from immintrin.h that the function uses. The inliner will be reponsible for merging this attribute when a function is inlined. We may also need a way to limit inlining in the future as well, but we can discuss that in the future.
To make things more complicated, there are two different ways intrinsics are implemented in immintrin.h. Either as an always_inline function containing calls to builtins(can be target specific or target independent) or vector extension code. Or as a macro wrapper around a taget specific builtin. I believe I've removed all cases where the macro was around a target independent builtin.
To support the always_inline function case this patch adds attribute((min_vector_width(128))) that can be used to tag these functions with their vector width. All x86 intrinsic functions that operate on vectors have been tagged with this attribute.
To support the macro case, all x86 specific builtins have also been tagged with the vector width that they require. Use of any builtin with this property will implicitly increase the min_vector_width of the function that calls it. I've done this as a new property in the attribute string for the builtin rather than basing it on the type string so that we can opt into it on a per builtin basis and avoid any impact to target independent builtins.
There will be future work to support vectors passed as function arguments and supporting inline assembly. And whatever else we can find that isn't covered by this patch.
Special thanks to Chandler who suggested this direction and reviewed a preview version of this patch. And thanks to Eric Christopher who has had many conversations with me about this issue.
Differential Revision: https://reviews.llvm.org/D48617
llvm-svn: 336583
conversions are only applied to operands of class type, and the second
standard conversion sequence is not applied.
When diagnosing an invalid builtin binary operator, talk about the
original types rather than the converted types. If these differ by a
user-defined conversion, tell the user what happened.
llvm-svn: 335781
Since we are now producing a summary also for regular LTO builds, we
need to run the NameAnonGlobals pass in those cases as well (the
summary cannot handle anonymous globals).
See https://reviews.llvm.org/D34156 for details on the original change.
This reverts commit 6c9ee4a4a438a8059aacc809b2dd57128fccd6b3.
llvm-svn: 335385
This is breaking a couple of buildbots. We need to run the
NameAnonGlobal pass for regular LTO now as well (since we're producing a
summary). I'll post a separate patch for review to make this happen and
then re-commit.
This reverts commit c0759b7b1f4a81ff9021b952aa38a222d5fa4dfd.
llvm-svn: 335291
Summary:
With D33921, we gained the ability to have module summaries in regular
LTO modules without triggering ThinLTO compilation. Module summaries in
regular LTO allow garbage collection (dead stripping) before LTO
compilation and thus open up additional optimization opportunities.
This patch enables summary emission in regular LTO for all targets
except ld64-based ones (which use the legacy LTO API).
Reviewers: pcc, tejohnson, mehdi_amini
Subscribers: inglorion, eraman, cfe-commits
Differential Revision: https://reviews.llvm.org/D34156
llvm-svn: 335284
... instead of prepending it at the beginning (the original behavior
since implemented in r122535 2010-12-23). This builds up an
AttributeList in the the order in which the attributes appear in the
source.
The reverse order caused nodes for attributes in the AST (e.g. LoopHint)
to be in the reverse, and therefore printed in the wrong order by
-ast-dump. Some TODO comments mention this. The order was explicitly
reversed for enable_if attribute overload resolution and name mangling,
which is not necessary anymore with this patch.
The change unfortunately has some secondary effects, especially for
diagnostic output. In the simplest cases, the CHECK lines or expected
diagnostic were changed to the the new output. If the kind of
error/warning changed, the attribute's order was changed instead.
It also causes some 'previous occurrence here' hints to be textually
after the main marker. This typically happens when attributes are
merged, but are incompatible. Interchanging the role of the the main
and note SourceLocation will also cause the case where two different
declaration's attributes (in contrast to multiple attributes of the
same declaration) are merged to be reversed. There is no easy fix
because sometimes previous attributes are merged into a new
declaration's attribute list, sometimes new attributes are added to a
previous declaration's attribute list. Since 'previous occurrence here'
pointing to locations after the main marker is not rare, I left the
markers as-is; it is only relevant when the attributes are declared in
the same declaration anyway, which often is on the same line.
Differential Revision: https://reviews.llvm.org/D48100
llvm-svn: 335084
The recommit ensures that the tests that failed on bots don't trigger the warning.
Xcode 10 removes support for libstdc++, but the users just get a confusing
include not file warning when including an STL header (when building for iOS6
which uses libstdc++ by default for example).
This patch adds a new warning that lets the user know that the libstdc++ include
path was not found to ensure that the user is more aware of why the error occurs.
rdar://40830462
Differential Revision: https://reviews.llvm.org/D48297
llvm-svn: 335081
E. g. use "10.11" instead of "10_11".
We are maintaining backward compatibility by parsing underscore-delimited version tuples but no longer keep track of the separator and using dot format for output.
Differential Revision: https://reviews.llvm.org/D46747
rdar://problem/39845032
llvm-svn: 332598
It was failing because on Windows, -ast-print prints
__single_inheritance(1) before T1.
Adding a triple is a stop-gap fix until it can be fixed properly.
llvm-svn: 332335
For example, given:
struct T1 {
struct T2 *p0;
};
-ast-print produced:
struct T1 {
struct T2;
struct T2 *p0;
};
Compiling that produces a warning that the first struct T2 declaration
does not declare anything.
Details:
A tag decl group is one or more decls that share a type specifier that
is a tag decl (that is, a struct/union/class/enum decl). Within
functions, the parser builds such a tag decl group as part of a
DeclStmt. However, in decl contexts, such as file scope or a member
list, the parser does not group together the members of a tag decl
group. Previously, detection of tag decl groups during printing was
implemented but only if the tag decl was unnamed. Otherwise, as in
the above example, the members of the group did not print together and
so sometimes introduced warnings.
This patch extends detection of tag decl groups in decl contexts to
any tag decl that is recorded in the AST as not free-standing.
Reviewed by: rsmith
Differential Revision: https://reviews.llvm.org/D45465
llvm-svn: 332314
For example, given:
void fn() {
struct T *p0;
struct T { int i; } *p1;
}
-ast-print produced:
void fn() {
struct T { int i; } *p0;
struct T { int i; } *p1;
}
Compiling that fails with a redefinition error.
Given:
void fn() {
struct T *p0;
struct __attribute__((deprecated)) T *p1;
}
-ast-print dropped the attribute.
Details:
For a tag specifier (that is, struct/union/class/enum used as a type
specifier in a declaration) that was also a tag declaration (that is,
first occurrence of the tag) or tag redeclaration (that is, later
occurrence that specifies attributes or a member list), clang printed
the tag specifier as either (1) the full tag definition if one
existed, or (2) the first tag declaration otherwise. Redefinition
errors were sometimes introduced, as in the first example above. Even
when that was impossible because no member list was ever specified,
attributes were sometimes lost, thus changing semantics and
diagnostics, as in the second example above.
This patch fixes a major culprit for these problems. It does so by
creating an ElaboratedType with a new OwnedDecl member wherever an
occurrence of a tag type is a (re)declaration of that tag type.
PrintingPolicy's IncludeTagDefinition used to trigger printing of the
member list, attributes, etc. for a tag specifier by using a tag
(re)declaration selected as described above. Now, it triggers the
same thing except it uses the tag (re)declaration stored in the
OwnedDecl. Of course, other tooling can now make use of the new
OwnedDecl as well.
Also, to be more faithful to the original source, this patch
suppresses printing of attributes inherited from previous
declarations.
Reviewed by: rsmith, aaron.ballman
Differential Revision: https://reviews.llvm.org/D45463
llvm-svn: 332281
For example, given:
#define bool _Bool
_Bool i;
void fn() { 1; }
-ast-print produced:
tmp.c:3:13: warning: expression result unused
void fn() { 1; }
^
bool i;
void fn() {
1;
}
That fails to compile because bool is undefined.
Details:
Diagnostics print _Bool as bool when the latter is defined as the
former. However, diagnostics were altering the printing policy for
-ast-print as well. The printed source was then invalid because the
preprocessor eats the bool definition.
Problematic diagnostics included suppressed warnings (e.g., add
-Wno-unused-value to the above example), including those that are
suppressed by default.
This patch fixes this bug and cleans up some related comments.
Reviewed by: aaron.ballman, rsmith
Differential Revision: https://reviews.llvm.org/D45093
llvm-svn: 332275
The C standard doesn't allow comparisons like "f1 < f2" (where f1 and f2
are function pointers), but we allow them as an extension. Add a
warning flag to control this warning.
Differential Revision: https://reviews.llvm.org/D46155
llvm-svn: 331570
When a '>>' token is split into two '>' tokens (in C++11 onwards), or (as an
extension) when we do the same for other tokens starting with a '>', we can't
just use a location pointing to the first '>' as the location of the split
token, because that would result in our miscomputing the length and spelling
for the token. As a consequence, for example, a refactoring replacing 'A<X>'
with something else would sometimes replace one character too many, and
similarly diagnostics highlighting a template-id source range would highlight
one character too many.
Fix this by creating an expansion range covering the first character of the
'>>' token, whose spelling is '>'. For this to work, we generalize the
expansion range of a macro FileID to be either a token range (the common case)
or a character range (used in this new case).
llvm-svn: 331155
Found via codespell -q 3 -I ../clang-whitelist.txt
Where whitelist consists of:
archtype
cas
classs
checkk
compres
definit
frome
iff
inteval
ith
lod
methode
nd
optin
ot
pres
statics
te
thru
Patch by luzpaz! (This is a subset of D44188 that applies cleanly with a few
files that have dubious fixes reverted.)
Differential revision: https://reviews.llvm.org/D44188
llvm-svn: 329399
The patch adds nocf_check target independent attribute for disabling checks that were enabled by cf-protection flag.
The attribute can be appertained to functions and function pointers.
Attribute name follows GCC's similar attribute name.
Differential Revision: https://reviews.llvm.org/D41880
llvm-svn: 327768
More generally, this permits a template to be specialized in any scope in which
it could be defined, so this also supersedes DR44 and DR374 (the latter of
which we previously only implemented in C++11 mode onwards due to unclarity as
to whether it was a DR).
llvm-svn: 327705
The patch fixes a number of bugs related to parameter indexing in
attributes:
* Parameter indices in some attributes (argument_with_type_tag,
pointer_with_type_tag, nonnull, ownership_takes, ownership_holds,
and ownership_returns) are specified in source as one-origin
including any C++ implicit this parameter, were stored as
zero-origin excluding any this parameter, and were erroneously
printing (-ast-print) and confusingly dumping (-ast-dump) as the
stored values.
* For alloc_size, the C++ implicit this parameter was not subtracted
correctly in Sema, leading to assert failures or to silent failures
of __builtin_object_size to compute a value.
* For argument_with_type_tag, pointer_with_type_tag, and
ownership_returns, the C++ implicit this parameter was not added
back to parameter indices in some diagnostics.
This patch fixes the above bugs and aims to prevent similar bugs in
the future by introducing careful mechanisms for handling parameter
indices in attributes. ParamIdx stores a parameter index and is
designed to hide the stored encoding while providing accessors that
require each use (such as printing) to make explicit the encoding that
is needed. Attribute declarations declare parameter index arguments
as [Variadic]ParamIdxArgument, which are exposed as ParamIdx[*]. This
patch rewrites all attribute arguments that are processed by
checkFunctionOrMethodParameterIndex in SemaDeclAttr.cpp to be declared
as [Variadic]ParamIdxArgument. The only exception is xray_log_args's
argument, which is encoded as a count not an index.
Differential Revision: https://reviews.llvm.org/D43248
llvm-svn: 326602
- Expand GK_*s (i.e. GFX6 -> GFX600, GFX601, etc.)
- This allows us to choose features correctly in some cases (for example, fast fmaf is available on gfx600, but not gfx601)
- Move HasFMAF, HasFP64, HasLDEXPF to GPUInfo tables
- Add HasFastFMA, HasFastFMAF to GPUInfo tables
- Add missing tests
llvm-svn: 326254
Summary:
-ast-print prints omp pragmas with a trailing space. While this
behavior is likely of little concern to most users, surely it's
unintentional, and it's annoying for some source-level work I'm
pursuing. This patch focuses on omp pragmas, but it also fixes
init_seg and loop hint pragmas because they share implementation.
The testing strategy here is to add usually just one '{{$}}' per
relevant -ast-print test file. This seems to achieve good code
coverage. However, this strategy is probably easy to forget as the
tests evolve. That's probably fine as this fix is far from critical.
The main goal of the testing is to aid the initial review.
This patch also adds a fixme for "#pragma unroll", which prints as
"#pragma unroll (enable)", which is invalid syntax.
Reviewers: ABataev
Reviewed By: ABataev
Subscribers: guansong, cfe-commits
Differential Revision: https://reviews.llvm.org/D43204
llvm-svn: 325145
Louis Dionne