Summary:
Convert clang::LangAS to a strongly typed enum
Currently both clang AST address spaces and target specific address spaces
are represented as unsigned which can lead to subtle errors if the wrong
type is passed. It is especially confusing in the CodeGen files as it is
not possible to see what kind of address space should be passed to a
function without looking at the implementation.
I originally made this change for our LLVM fork for the CHERI architecture
where we make extensive use of address spaces to differentiate between
capabilities and pointers. When merging the upstream changes I usually
run into some test failures or runtime crashes because the wrong kind of
address space is passed to a function. By converting the LangAS enum to a
C++11 we can catch these errors at compile time. Additionally, it is now
obvious from the function signature which kind of address space it expects.
I found the following errors while writing this patch:
- ItaniumRecordLayoutBuilder::LayoutField was passing a clang AST address
space to TargetInfo::getPointer{Width,Align}()
- TypePrinter::printAttributedAfter() prints the numeric value of the
clang AST address space instead of the target address space.
However, this code is not used so I kept the current behaviour
- initializeForBlockHeader() in CGBlocks.cpp was passing
LangAS::opencl_generic to TargetInfo::getPointer{Width,Align}()
- CodeGenFunction::EmitBlockLiteral() was passing a AST address space to
TargetInfo::getPointerWidth()
- CGOpenMPRuntimeNVPTX::translateParameter() passed a target address space
to Qualifiers::addAddressSpace()
- CGOpenMPRuntimeNVPTX::getParameterAddress() was using
llvm::Type::getPointerTo() with a AST address space
- clang_getAddressSpace() returns either a LangAS or a target address
space. As this is exposed to C I have kept the current behaviour and
added a comment stating that it is probably not correct.
Other than this the patch should not cause any functional changes.
Reviewers: yaxunl, pcc, bader
Reviewed By: yaxunl, bader
Subscribers: jlebar, jholewinski, nhaehnle, Anastasia, cfe-commits
Differential Revision: https://reviews.llvm.org/D38816
llvm-svn: 315871
This reverts r314461.
It is warning on user code that uses END_COM_MAP(), which expands to
declare QueryInterface with conflicting exception specifers. I've spent
a while trying to understand why, but haven't been able to extract a
reduced test case. Let's revert and I'll keep trying.
llvm-svn: 314689
I discovered it was possible to create a 'nothrow' noexcept(false)
function, which is both non-sensical as well as seemingly breaking.
This patch warns if attribute nothrow is used with anything besides "noexcept".
"noexcept(true)" isn't possible, because the noexcept decl isn't parsed until
later.
Differential Revision: https://reviews.llvm.org/D38205
llvm-svn: 314461
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.
This recommits r313722, which was reverted in r313725 because clang
couldn't build compiler-rt. It failed to build because there were
function declarations that were missing 'noescape'. That has been fixed
in r313929.
rdar://problem/19886775
Differential Revision: https://reviews.llvm.org/D32210
llvm-svn: 313945
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
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
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
This made it awkward to switch over an enum where some entries
are partial and is unlikley to catch any bugs.
Differential revision: https://reviews.llvm.org/D36777
llvm-svn: 311191
Base::TraverseStmt when visiting the then/else branches of if statements
This ensures that the statement stack is correctly tracked and correct
multi-statement fixit is generated inside of an if (@available)
llvm-svn: 311088
This reverts commit rL310403, which caused spurious warnings in libc++,
because it didn't properly handle templated scoped lockable types.
llvm-svn: 310698
Add warnings in cases where an implicit `this` argument is expected to
attributes because either `this` doesn't exist because the attribute is
on a free function, or because `this` is on a type that doesn't have a
corresponding capability/lockable/scoped_lockable attribute.
Reviewers: delesley, aaron.ballman
Differential Revision: https://reviews.llvm.org/D36237
llvm-svn: 310403
Delete the test that was broken by rL309725, and add it back in a
follow up commit. Also, improve the tests a bit.
Reviewers: delesley, aaron.ballman
Differential Revision: https://reviews.llvm.org/D36237
llvm-svn: 310402
An ABI change was introduced in r254596 that modified structure layouts when the 'packed' attribute was used on one-byte bitfields. Since the PS4 target needs to maintain backwards compatibility for all structure layouts, this change reintroduces the old behavior for PS4 targets only. It also introduces PS4 specific cases to the relevant test.
Patch by Matthew Voss.
llvm-svn: 310388
This patch adds support for the `long_call`, `far`, and `near` attributes
for MIPS targets. The `long_call` and `far` attributes are synonyms. All
these attributes override `-mlong-calls` / `-mno-long-calls` command
line options for particular function.
Differential revision: https://reviews.llvm.org/D35479
llvm-svn: 308667
Move builtins from the x86 specific scope into the global
scope. Their use is still limited to x86_64 and aarch64 though.
This allows wine on aarch64 to properly handle variadic functions.
Differential Revision: https://reviews.llvm.org/D34475
llvm-svn: 308218
be shared without warnings. Build AttributedTypes to leave breadcrumbs
for tools like the static analyzer. Warn about attempting to use the
attribute with incompatible return types.
llvm-svn: 308092
The new compiler warning -Wunguarded-availability-new is a subset of
-Wunguarded-availability. It is on by default. It only warns about uses of APIs
that have been introduced in macOS >= 10.13, iOS >= 11, watchOS >= 4 and
tvOS >= 11. We decided to use this kind of solution as we didn't want to turn
on -Wunguarded-availability by default, because we didn't want our users to get
warnings about uses of old APIs in their existing projects.
rdar://31054725
Differential Revision: https://reviews.llvm.org/D34264
llvm-svn: 306033
Summary:
Before this change, we couldn't capture the `this` pointer that's
implicitly the first argument of class member functions. There are some
interesting things we can do with capturing even just this single
argument for zero-argument member functions.
Reviewers: rnk, pelikan
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D34052
llvm-svn: 305544
This is an initial commit to allow using it with constant expressions, a follow-up commit will enable full support for it in ObjC methods.
llvm-svn: 303712
This patch adds support for the `micromips` and `nomicromips` attributes
for MIPS targets.
Differential revision: https://reviews.llvm.org/D33363
llvm-svn: 303546
`__builtin_available`
This commit allows us to use the macOS/iOS/tvOS/watchOS platform names in
`@available`/`__builtin_available`.
rdar://32067795
Differential Revision: https://reviews.llvm.org/D33000
llvm-svn: 302540
This patch adds a fix-it for the -Wunguarded-availability warning. This fix-it
is similar to the Swift one: it suggests that you wrap the statement in an
`if (@available)` check. The produced fixits are indented (just like the Swift
ones) to make them look nice in Xcode's fix-it preview.
rdar://31680358
Differential Revision: https://reviews.llvm.org/D32424
llvm-svn: 302253
blocks and lambdas
Prior to this commit Clang emitted the old "partial availability" warning for
expressions that referred to declarations that were not yet introduced in
blocks and lambdas that were not in a function/method. This commit ensures that
top-level blocks and lambdas use the new unguarded availability checks.
rdar://31835952
llvm-svn: 301409
Prior to this commit the external_source_symbol attribute wasn't supported by
#pragma clang attribute for the following two reasons:
- The Named attribute subject hasn't been supported by TableGen.
- There was no way to specify a subject match rule for #pragma clang attribute
that could operate on a set of attribute subjects (e.g. the ones that derive
from NamedDecl).
This commit fixes the two issues and thus adds external_source_symbol support to
#pragma clang attribute.
rdar://31169028
Differential Revision: https://reviews.llvm.org/D32176
llvm-svn: 300712
This is a recommit of r300539 that was reverted in r300543 due to test failures.
The original commit message is displayed below:
The new '#pragma clang attribute' directive can be used to apply attributes to
multiple declarations. An attribute must satisfy the following conditions to
be supported by the pragma:
- It must have a subject list that's defined in the TableGen file.
- It must be documented.
- It must not be late parsed.
- It must have a GNU/C++11 spelling.
Differential Revision: https://reviews.llvm.org/D30009
llvm-svn: 300556
The new '#pragma clang attribute' directive can be used to apply attributes to
multiple declarations. An attribute must satisfy the following conditions to
be supported by the pragma:
- It must have a subject list that's defined in the TableGen file.
- It must be documented.
- It must not be late parsed.
- It must have a GNU/C++11 spelling.
Differential Revision: https://reviews.llvm.org/D30009
llvm-svn: 300539
MSDN (https://msdn.microsoft.com/en-us/library/h5w10wxs.aspx) indicates
that `__declspec(naked)` is only permitted on x86 and ARM targets.
Testing with cl does confirm this behaviour. Provide a warning for use
of `__declspec(naked)` on x64.
llvm-svn: 299774
GCC has the alloc_align attribute, which is similar to assume_aligned, except the attribute's parameter is the index of the integer parameter that needs aligning to.
Differential Revision: https://reviews.llvm.org/D29599
llvm-svn: 299117
Summary:
This patch implements parsing of [[clang::suppress(rule, ...)]]
and [[gsl::suppress(rule, ...)]] attributes.
C++ Core Guidelines depend heavily on tool support for
rule enforcement. They also propose a way to suppress
warnings [1] which is by annotating any ancestor in AST
with the C++11 attribute [[gsl::suppress(rule1,...)]].
To have a mechanism to suppress non-C++ Core
Guidelines specific, an additional spelling of [[clang::suppress]]
is defined.
For example, to suppress the warning cppcoreguidelines-slicing,
one could do
```
[[clang::suppress("cppcoreguidelines-slicing")]]
void f() { ... code that does slicing ... }
```
or
```
void g() {
Derived b;
[[clang::suppress("cppcoreguidelines-slicing")]]
Base a{b};
[[clang::suppress("cppcoreguidelines-slicing")]] {
doSomething();
Base a2{b};
}
}
```
This parsing can then be used by clang-tidy, which includes multiple
C++ Core Guidelines rules, to suppress warnings (see
https://reviews.llvm.org/D24888).
For the exact naming of the rule in the attribute, there
are different possibilities, which will be defined in the
corresponding clang-tidy patch.
Currently, clang-tidy supports suppressing of warnings through "//
NOLINT" comments. There are some advantages that the attribute has:
- Suppressing specific warnings instead of all warnings
- Suppressing warnings in a block (namespace, function, compound
statement)
- Code formatting may split a statement into multiple lines,
thus a "// NOLINT" comment may be on the wrong line
I'm looking forward to your comments!
[1] https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#inforce-enforcement
Reviewers: alexfh, aaron.ballman, rsmith
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D24886
llvm-svn: 298880
Correct class-template deprecation behavior
Based on the comment in the test, and my reading of the standard, a deprecated warning should be issued in the following case:
template<typename T> [[deprecated]] class Foo{}; Foo<int> f;
This was not the case, because the ClassTemplateSpecializationDecl creation did not also copy the deprecated attribute.
Note: I did NOT audit the complete set of attributes to see WHICH ones should be copied, so instead I simply copy ONLY the deprecated attribute.
Previous DiffRev: https://reviews.llvm.org/D27486, was reverted.
This patch fixes the issues brought up here by the reverter: https://reviews.llvm.org/rL298410
Differential Revision: https://reviews.llvm.org/D31245
llvm-svn: 298634
Based on the comment in the test, and my reading of the standard, a deprecated warning should be issued in the following case:
template<typename T> [[deprecated]] class Foo{}; Foo<int> f;
This was not the case, because the ClassTemplateSpecializationDecl creation did not also copy the deprecated attribute.
Note: I did NOT audit the complete set of attributes to see WHICH ones should be copied, so instead I simply copy ONLY the deprecated attribute.
Differential Revision: https://reviews.llvm.org/D27486
llvm-svn: 298410
This commit adds support for a new attribute that will be used to
distinguish between extensible and inextensible enums. There are three
main purposes of this attribute:
1. Give better control over when enum-related warnings are issued.
For example, in the code below, clang will not issue a -Wassign-enum
warning if the enum is marked "open":
enum __attribute__((enum_extensibility(closed))) EnumClosed {
B0 = 1, B1 = 10
};
enum __attribute__((enum_extensibility(open))) EnumOpen {
C0 = 1, C1 = 10
};
enum EnumClosed ec = 100; // warning issued
enum EnumOpen eo = 100; // no warning
2. Enable code-completion and debugging tools to offer better
suggestions.
3. Make it easier for swift's clang importer to determine which swift
type an enum should be mapped to.
For more details, see the discussion I started on cfe-dev:
http://lists.llvm.org/pipermail/cfe-dev/2017-February/052748.html
rdar://problem/12764379
rdar://problem/23145650
Differential Revision: https://reviews.llvm.org/D30766
llvm-svn: 298332
Summary:
Functions with the "xray_log_args" attribute will tell LLVM to emit a special
XRay sled for compiler-rt to copy any call arguments to your logging handler.
Reviewers: dberris
Reviewed By: dberris
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D29704
llvm-svn: 296999
and the nature of a declaration
This commit adds an external_source_symbol attribute to Clang. This attribute
specifies that a declaration originates from an external source and describes
the nature of that source. This attribute will be used to improve IDE features
like 'jump-to-definition' for mixed-language projects or project that use
auto-generated code.
rdar://30423368
Differential Revision: https://reviews.llvm.org/D29819
llvm-svn: 296649
instantiation.
In preparation for converting the template stack to a more general context
stack (so we can include context notes for other kinds of context).
llvm-svn: 295686
Summary:
This teaches clang how to parse and lower the 'interrupt' and 'naked'
attributes.
This allows interrupt signal handlers to be written.
Reviewers: aaron.ballman
Subscribers: malcolm.parsons, cfe-commits
Differential Revision: https://reviews.llvm.org/D28451
llvm-svn: 294402
`diagnose_if` can be used to have clang emit either warnings or errors
for function calls that meet user-specified conditions. For example:
```
constexpr int foo(int a)
__attribute__((diagnose_if(a > 10, "configurations with a > 10 are "
"expensive.", "warning")));
int f1 = foo(9);
int f2 = foo(10); // warning: configuration with a > 10 are expensive.
int f3 = foo(f2);
```
It currently only emits diagnostics in cases where the condition is
guaranteed to always be true. So, the following code will emit no
warnings:
```
constexpr int bar(int a) {
foo(a);
return 0;
}
constexpr int i = bar(10);
```
We hope to support optionally emitting diagnostics for cases like that
(and emitting runtime checks) in the future.
Release notes will appear shortly. :)
Differential Revision: https://reviews.llvm.org/D27424
llvm-svn: 291418
This is a recommit of r290149, which was reverted in r290169 due to msan
failures. msan was failing because we were calling
`isMostDerivedAnUnsizedArray` on an invalid designator, which caused us
to read uninitialized memory. To fix this, the logic of the caller of
said function was simplified, and we now have a `!Invalid` assert in
`isMostDerivedAnUnsizedArray`, so we can catch this particular bug more
easily in the future.
Fingers crossed that this patch sticks this time. :)
Original commit message:
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
llvm-svn: 290297
This commit fails MSan when running test/CodeGen/object-size.c in
a confusing way. After some discussion with George, it isn't really
clear what is going on here. We can make the MSan failure go away by
testing for the invalid bit, but *why* things are invalid isn't clear.
And yet, other code in the surrounding area is doing precisely this and
testing for invalid.
George is going to take a closer look at this to better understand the
nature of the failure and recommit it, for now backing it out to clean
up MSan builds.
llvm-svn: 290169
This patch does three things:
- Gives us the alloc_size attribute in clang, which lets us infer the
number of bytes handed back to us by malloc/realloc/calloc/any user
functions that act in a similar manner.
- Teaches our constexpr evaluator that evaluating some `const` variables
is OK sometimes. This is why we have a change in
test/SemaCXX/constant-expression-cxx11.cpp and other seemingly
unrelated tests. Richard Smith okay'ed this idea some time ago in
person.
- Uniques some Blocks in CodeGen, which was reviewed separately at
D26410. Lack of uniquing only really shows up as a problem when
combined with our new eagerness in the face of const.
Differential Revision: https://reviews.llvm.org/D14274
llvm-svn: 290149
Although not specifically mentioned in the documentation, MSVC accepts
__uuidof(…) and declspec(uuid("…")) attributes on enumeration types in
addition to structs/classes. This is meaningful, as such types *do* have
associated UUIDs in ActiveX typelibs, and such attributes are included
by default in the wrappers generated by their #import construct, so they
are not particularly unusual.
clang currently rejects the declspec with a –Wignored-attributes
warning, and errors on __uuidof() with “cannot call operator __uuidof on
a type with no GUID” (because it rejected the uuid attribute, and
therefore finds no value). This is causing problems for us while trying
to use clang-tidy on a codebase that makes heavy use of ActiveX.
I believe I have found the relevant places to add this functionality,
this patch adds this case to clang’s implementation of these MS
extensions. patch is against r285994 (or actually the git mirror
80464680ce).
Both include an update to test/Parser/MicrosoftExtensions.cpp to
exercise the new functionality.
This is my first time contributing to LLVM, so if I’ve missed anything
else needed to prepare this for review just let me know!
__uuidof: https://msdn.microsoft.com/en-us/library/zaah6a61.aspx
declspec(uuid("…")): https://msdn.microsoft.com/en-us/library/3b6wkewa.aspx
#import: https://msdn.microsoft.com/en-us/library/8etzzkb6.aspx
Reviewers: aaron.ballman, majnemer, rnk
Differential Revision: https://reviews.llvm.org/D26846
llvm-svn: 289567
This patch implements the register call calling convention, which ensures
as many values as possible are passed in registers. CodeGen changes
were committed in https://reviews.llvm.org/rL284108.
Differential Revision: https://reviews.llvm.org/D25204
llvm-svn: 285849
Certain OpenCL builtin functions are supposed to be executed by all threads in a work group or sub group. Such functions should not be made divergent during transformation. It makes sense to mark them with convergent attribute.
The adding of convergent attribute is based on Ettore Speziale's work and the original proposal and patch can be found at https://www.mail-archive.com/cfe-commits@lists.llvm.org/msg22271.html.
Differential Revision: https://reviews.llvm.org/D25343
llvm-svn: 285725
This is done so that the following compiles with no warnings:
int fn(type_10_12) __attribute__((availability(macos, introduced=10.12)));
Differential revision: https://reviews.llvm.org/D25284
llvm-svn: 285457
This patch adds an objc_subclassing_restricted attribute into clang. This
attribute acts similarly to 'final' - Objective-C classes with this attribute
can't be subclassed. However, @interface declarations that have
objc_subclassing_restricted but don't have @implementation are allowed to
inherit other @interface declarations with objc_subclassing_restricted. This is
needed to describe the Swift class hierarchy in clang while making sure that
the Objective-C classes cannot subclass the Swift classes.
This attribute is already implemented in a fork of clang that's used for Swift
(https://github.com/apple/swift-clang) and this patch moves that code to the
upstream clang repository.
rdar://28937548
Differential Revision: https://reviews.llvm.org/D25993
llvm-svn: 285391
The problem with the original commit was that some of Apple's headers depended
on an incorrect behaviour, this commit adds a temporary workaround until those
headers are fixed.
llvm-svn: 285098
This reverts commit r285007 and reapply r284990, with a fix for the
opencl test that I broke. Original commit message follows:
These new builtins support a mechanism for logging OS events, using a
printf-like format string to specify the layout of data in a buffer.
The _buffer_size version of the builtin can be used to determine the size
of the buffer to allocate to hold the data, and then __builtin_os_log_format
can write data into that buffer. This implements format checking to report
mismatches between the format string and the data arguments. Most of this
code was written by Chris Willmore.
Differential Revision: https://reviews.llvm.org/D25888
llvm-svn: 285019
These new builtins support a mechanism for logging OS events, using a
printf-like format string to specify the layout of data in a buffer.
The _buffer_size version of the builtin can be used to determine the size
of the buffer to allocate to hold the data, and then __builtin_os_log_format
can write data into that buffer. This implements format checking to report
mismatches between the format string and the data arguments. Most of this
code was written by Chris Willmore.
Differential Revision: https://reviews.llvm.org/D25888
llvm-svn: 284990
This commit combines a couple of redundant functions that do availability
attribute context checking into a more correct/simpler one.
Differential revision: https://reviews.llvm.org/D25283
llvm-svn: 284265
This commit fixes a crash that happens when clang is analyzing a
transparent_union attribute on a union which has a field with incomplete type.
rdar://28630028
Differential Revision: https://reviews.llvm.org/D25273
llvm-svn: 283432
Also add a test that we disallow
__constant__ __shared__ int x;
because it's possible to break this without breaking
__shared__ __constant__ int x;
Reviewers: rnk
Subscribers: cfe-commits, tra
Differential Revision: https://reviews.llvm.org/D25125
llvm-svn: 282985
__attribute__((amdgpu_flat_work_group_size(<min>, <max>))) - request minimum and maximum flat work group size
__attribute__((amdgpu_waves_per_eu(<min>[, <max>]))) - request minimum and/or maximum waves per execution unit
Differential Revision: https://reviews.llvm.org/D24513
llvm-svn: 282371
This mostly behaves cl.exe's behavior, even though clang-cl is stricter in some
corner cases and more lenient in others (see the included test).
To make the uuid declared previously here diagnostic work correctly, tweak
stripTypeAttributesOffDeclSpec() to keep attributes in the right order.
https://reviews.llvm.org/D24469
llvm-svn: 281367
Summary:
This attribute specifies expectations about the initialization of static and
thread local variables. Specifically that the variable has a
[constant initializer](http://en.cppreference.com/w/cpp/language/constant_initialization)
according to the rules of [basic.start.static]. Failure to meet this expectation
will result in an error.
Static objects with constant initializers avoid hard-to-find bugs caused by
the indeterminate order of dynamic initialization. They can also be safely
used by other static constructors across translation units.
This attribute acts as a compile time assertion that the requirements
for constant initialization have been met. Since these requirements change
between dialects and have subtle pitfalls it's important to fail fast instead
of silently falling back on dynamic initialization.
```c++
// -std=c++14
#define SAFE_STATIC __attribute__((require_constant_initialization)) static
struct T {
constexpr T(int) {}
~T();
};
SAFE_STATIC T x = {42}; // OK.
SAFE_STATIC T y = 42; // error: variable does not have a constant initializer
// copy initialization is not a constant expression on a non-literal type.
```
This attribute can only be applied to objects with static or thread-local storage
duration.
Reviewers: majnemer, rsmith, aaron.ballman
Subscribers: jroelofs, cfe-commits
Differential Revision: https://reviews.llvm.org/D23385
llvm-svn: 280525
Summary:
This attribute specifies expectations about the initialization of static and
thread local variables. Specifically that the variable has a
[constant initializer](http://en.cppreference.com/w/cpp/language/constant_initialization)
according to the rules of [basic.start.static]. Failure to meet this expectation
will result in an error.
Static objects with constant initializers avoid hard-to-find bugs caused by
the indeterminate order of dynamic initialization. They can also be safely
used by other static constructors across translation units.
This attribute acts as a compile time assertion that the requirements
for constant initialization have been met. Since these requirements change
between dialects and have subtle pitfalls it's important to fail fast instead
of silently falling back on dynamic initialization.
```c++
// -std=c++14
#define SAFE_STATIC __attribute__((require_constant_initialization)) static
struct T {
constexpr T(int) {}
~T();
};
SAFE_STATIC T x = {42}; // OK.
SAFE_STATIC T y = 42; // error: variable does not have a constant initializer
// copy initialization is not a constant expression on a non-literal type.
```
This attribute can only be applied to objects with static or thread-local storage
duration.
Reviewers: majnemer, rsmith, aaron.ballman
Subscribers: jroelofs, cfe-commits
Differential Revision: https://reviews.llvm.org/D23385
llvm-svn: 280516
This commit adds a traversal of the AST after Sema of a function that diagnoses
unguarded references to declarations that are partially available (based on
availability attributes). This traversal is only done when we would otherwise
emit -Wpartial-availability.
This commit is part of a feature I proposed here:
http://lists.llvm.org/pipermail/cfe-dev/2016-July/049851.html
Differential revision: https://reviews.llvm.org/D23003
llvm-svn: 278826
Summary:
Based on a patch by Michael Mueller.
This attribute specifies that a function can be hooked or patched. This
mechanism was originally devised by Microsoft for hotpatching their
binaries (which they're constantly updating to stay ahead of crackers,
script kiddies, and other ne'er-do-wells on the Internet), but it's now
commonly abused by Windows programs that want to hook API functions. It
is for this reason that this attribute was added to GCC--hence the name,
`ms_hook_prologue`.
Depends on D19908.
Reviewers: rnk, aaron.ballman
Subscribers: cfe-commits
Differential Revision: https://reviews.llvm.org/D19909
llvm-svn: 278050
This means that a function marked with an availability attribute can safely
refer to a declaration that is greater than the deployment target, but less then
or equal to the context availability without -Wpartial-availability firing.
Differential revision: https://reviews.llvm.org/D22697
llvm-svn: 277058
-fxray-instrument: enables XRay annotation of IR
-fxray-instruction-threshold: configures the threshold for function size (looking at IR instructions), and allow LLVM to decide whether to add the nop sleds later on in the process.
Also implements the related xray_always_instrument and xray_never_instrument function attributes.
Patch by Dean Michael Berris.
llvm-svn: 275330
Alexander Richardson