The warning warns on TypedefNameDecls -- typedefs and C++11 using aliases --
that are !isReferenced(). Since the isReferenced() bit on TypedefNameDecls
wasn't used for anything before this warning it wasn't always set correctly,
so this patch also adds a few missing MarkAnyDeclReferenced() calls in
various places for TypedefNameDecls.
This is made a bit complicated due to local typedefs possibly being used only
after their local scope has closed. Consider:
template <class T>
void template_fun(T t) {
typename T::Foo s3foo; // YYY
(void)s3foo;
}
void template_fun_user() {
struct Local {
typedef int Foo; // XXX
} p;
template_fun(p);
}
Here the typedef in XXX is only used at end-of-translation unit, when YYY in
template_fun() gets instantiated. To handle this, typedefs that are unused when
their scope exits are added to a set of potentially unused typedefs, and that
set gets checked at end-of-TU. Typedefs that are still unused at that point then
get warned on. There's also serialization code for this set, so that the
warning works with precompiled headers and modules. For modules, the warning
is emitted when the module is built, for precompiled headers each time the
header gets used.
Finally, consider a function using C++14 auto return types to return a local
type defined in a header:
auto f() {
struct S { typedef int a; };
return S();
}
Here, the typedef escapes its local scope and could be used by only some
translation units including the header. To not warn on this, add a
RecursiveASTVisitor that marks all delcs on local types returned from auto
functions as referenced. (Except if it's a function with internal linkage, or
the decls are private and the local type has no friends -- in these cases, it
_is_ safe to warn.)
Several of the included testcases (most of the interesting ones) were provided
by Richard Smith.
(gcc's spelling -Wunused-local-typedefs is supported as an alias for this
warning.)
llvm-svn: 217298
This innocuous statement to get the identifier info for __va_list_tag
was causing an assertion failure:
NextIsPrevious() && "decl became non-canonical unexpectedly"
if the __va_list_tag identifier was found in a PCH in some
circumstances, because it was looked up before the ASTReader had a Sema
object to use to find existing decls to merge with.
We could possibly move getting the identifier info even later, or make
it lazy if we wanted to, but this seemed like the minimal change.
Now why a PCH would have this identifier in the first place is a bit
mysterious. This seems to be related to the global module index in some
way, because when the test case is built without the global module index
it will not emit an identifier for __va_list_tag into the PCH, but with
the global module index it does.
llvm-svn: 217275
Summary:
This pragma is very rare. We could *hypothetically* lower some uses of
it down to @llvm.global_ctors, but given that GlobalOpt isn't able to
optimize prioritized global ctors today, there's really no point.
If we wanted to do this in the future, I would check if the section used
in the pragma started with ".CRT$XC" and had up to two characters after
it. Those two characters could form the 16-bit initialization priority
that we support in @llvm.global_ctors. We would have to teach LLVM to
lower prioritized global ctors on COFF as well.
This should let us compile some silly uses of this pragma in WebKit /
Blink.
Reviewers: rsmith, majnemer
Subscribers: cfe-commits
Differential Revision: http://reviews.llvm.org/D4549
llvm-svn: 213593
The compilation pipeline doesn't actually need to know about the high-level
concept of diagnostic mappings, and hiding the final computed level presents
several simplifications and other potential benefits.
The only exceptions are opportunistic checks to see whether expensive code
paths can be avoided for diagnostics that are guaranteed to be ignored at a
certain SourceLocation.
This commit formalizes that invariant by introducing and using
DiagnosticsEngine::isIgnored() in place of individual level checks throughout
lex, parse and sema.
llvm-svn: 211005
This patch adds support for the msvc pragmas section, bss_seg, code_seg,
const_seg and data_seg as well as support for __declspec(allocate()).
Additionally it corrects semantics and adds diagnostics for
__attribute__((section())) and the interaction between the attribute
and the msvc pragmas and declspec. In general conflicts should now be
well diganosed within and among these features.
In supporting the pragmas new machinery for uniform lexing for
msvc pragmas was introduced. The new machinery always lexes the
entire pragma and stores it on an annotation token. The parser
is responsible for parsing the pragma when the handling the
annotation token.
There is a known outstanding bug in this implementation in C mode.
Because these attributes and pragmas apply _only_ to definitions, we
process them at the time we detect a definition. Due to tentative
definitions in C, we end up processing the definition late. This means
that in C mode, everything that ends up in a BSS section will end up in
the _last_ BSS section rather than the one that was live at the time of
tentative definition, even if that turns out to be the point of actual
definition. This issue is not known to impact anything as of yet
because we are not aware of a clear use or use case for #pragma bss_seg
but should be fixed at some point.
Differential Revision=http://reviews.llvm.org/D3065#inline-16241
llvm-svn: 205810
These features are new in VS 2013 and are necessary in order to layout
std::ostream correctly. Currently we have an ABI incompatibility when
self-hosting with the 2013 stdlib in our convertible_fwd_ostream wrapper
in gtest.
This change adds another implicit attribute, MSVtorDispAttr, because
implicit attributes are currently the best way to make sure the
information stays on class templates through instantiation.
Reviewers: majnemer
Differential Revision: http://llvm-reviews.chandlerc.com/D2746
llvm-svn: 201274
These flags control the inheritance model initially used by the
translation unit.
Differential Revision: http://llvm-reviews.chandlerc.com/D2741
llvm-svn: 201175
Introduce a notion of a 'current representation method' for
pointers-to-members.
When starting out, this is set to 'best case' (representation method is
chosen by examining the class, selecting the smallest representation
that would work given the class definition or lack thereof).
This pragma allows the translation unit to dictate exactly what
representation to use, similar to how the inheritance model keywords
operate.
N.B. PCH support is forthcoming.
Differential Revision: http://llvm-reviews.chandlerc.com/D2723
llvm-svn: 201105
A return type is the declared or deduced part of the function type specified in
the declaration.
A result type is the (potentially adjusted) type of the value of an expression
that calls the function.
Rule of thumb:
* Declarations have return types and parameters.
* Expressions have result types and arguments.
llvm-svn: 200082
Fix a perennial source of confusion in the clang type system: Declarations and
function prototypes have parameters to which arguments are supplied, so calling
these 'arguments' was a stretch even in C mode, let alone C++ where default
arguments, templates and overloading make the distinction important to get
right.
Readability win across the board, especially in the casting, ADL and
overloading implementations which make a lot more sense at a glance now.
Will keep an eye on the builders and update dependent projects shortly.
No functional change.
llvm-svn: 199686
Additionally, remove the optional nature of the spelling list index when creating attributes. This is supported by table generating a Spelling enumeration when the spellings for an attribute are distinct enough to warrant it.
llvm-svn: 199378
There's been long-standing confusion over the role of these two options. This
commit makes the necessary changes to differentiate them clearly, following up
from r198936.
MicrosoftExt (aka. fms-extensions):
Enable largely unobjectionable Microsoft language extensions to ease
portability. This mode, also supported by gcc, is used for building software
like FreeBSD and Linux kernel extensions that share code with Windows drivers.
MSVCCompat (aka. -fms-compatibility, formerly MicrosoftMode):
Turn on a special mode supporting 'heinous' extensions for drop-in
compatibility with the Microsoft Visual C++ product. Standards-compilant C and
C++ code isn't guaranteed to work in this mode. Implies MicrosoftExt.
Note that full -fms-compatibility mode is currently enabled by default on the
Windows target, which may need tuning to serve as a reasonable default.
See cfe-commits for the full discourse, thread 'r198497 - Move MS predefined
type_info out of InitializePredefinedMacros'
No change in behaviour.
llvm-svn: 199209
MSVC defines size_t without any explicit declarations. This change
allows us to be compatible with TUs that depend on this declaration
appearing from nowhere.
llvm-svn: 199190
It was previously enabled in both but should only have been part of the drop-in
quirks mode that is 'MicrosoftMode' given that it's only useful for
compatibility with the Microsoft headers/runtime.
llvm-svn: 198548
Instead of keeping it in amongst the macros, build the declaration at Sema init
the same way we do with other predeclared and builtin types.
In practice this means the declaration is marked implicit and therefore won't
show up as an unwanted user-declared type in tooling which has been a
frequently reported issue (though I haven't been able to cook up a test).
llvm-svn: 198497
This commit kills off custom type specifier and keyword handling of OpenCL C
data types.
Although the OpenCL spec describes them as keywords, we can handle them more
elegantly as predefined types. This should provide better error correction and
code completion as well as simplifying the implementation.
The primary intention is however to simplify the C/C++ parser and save some
packed bits on AST structures that had been extended in r170432 just for
OpenCL.
llvm-svn: 197578
Hopefully Richard won't notice this terrible egregiocity - clearly the work of a malevolent poltergeist - fixed now ;)
No functionality change.
llvm-svn: 194439
No Functionality change.
This refactoring avoids having to call getCurLambda right after PushLambdaScope, to obtain the LambdaScopeInfo that was created during the call to PushLambdaScope.
llvm-svn: 194438
Delayed exception specification checking for defaulted members and virtual
destructors are both susceptible to mutation during iteration so we need to
swap and process the worklists.
This resolves both accepts-invalid and rejects-valid issues and moreover fixes
potential invalid memory access as the contents of the vectors change during
iteration and recursive template instantiation.
Checking can be further delayed where parent classes aren't yet fully defined.
This patch adds two assertions at end of TU to ensure no specs are left
unchecked as was happenning before the fix, plus a test case from Marshall Clow
for the defaulted member crash extracted from the libcxx headers.
Reviewed by Richard Smith.
llvm-svn: 192947
Delayed exception specification checking for defaulted members and virtual
destructors are both susceptible to mutation during iteration so we need to
process the worklists fully.
This resolves both accepts-invalid and rejects-valid issues and moreover fixes
potential invalid memory access as the contents of the vectors change during
iteration and recursive template instantiation.
This patch also adds two assertions at end of TU to ensure no specs are left
unchecked as was happenning before the fix, plus a test case from Marshall Clow
for the defaulted member crash extracted from the libcxx headers.
Reviewed by Richard Smith.
llvm-svn: 192914
Specifically, the following features are not included in this commit:
- any sort of capturing within generic lambdas
- generic lambdas within template functions and nested
within other generic lambdas
- conversion operator for captureless lambdas
- ensuring all visitors are generic lambda aware
(Although I have gotten some useful feedback on my patches of the above and will be incorporating that as I submit those patches for commit)
As an example of what compiles through this commit:
template <class F1, class F2>
struct overload : F1, F2 {
using F1::operator();
using F2::operator();
overload(F1 f1, F2 f2) : F1(f1), F2(f2) { }
};
auto Recursive = [](auto Self, auto h, auto ... rest) {
return 1 + Self(Self, rest...);
};
auto Base = [](auto Self, auto h) {
return 1;
};
overload<decltype(Base), decltype(Recursive)> O(Base, Recursive);
int num_params = O(O, 5, 3, "abc", 3.14, 'a');
Please see attached tests for more examples.
This patch has been reviewed by Doug and Richard. Minor changes (non-functionality affecting) have been made since both of them formally looked at it, but the changes involve removal of supernumerary return type deduction changes (since they are now redundant, with richard having committed a recent patch to address return type deduction for C++11 lambdas using C++14 semantics).
Some implementation notes:
- Add a new Declarator context => LambdaExprParameterContext to
clang::Declarator to allow the use of 'auto' in declaring generic
lambda parameters
- Add various helpers to CXXRecordDecl to facilitate identifying
and querying a closure class
- LambdaScopeInfo (which maintains the current lambda's Sema state)
was augmented to house the current depth of the template being
parsed (id est the Parser calls Sema::RecordParsingTemplateParameterDepth)
so that SemaType.cpp::ConvertDeclSpecToType may use it to immediately
generate a template-parameter-type when 'auto' is parsed in a generic
lambda parameter context. (i.e we do NOT use AutoType deduced to
a template parameter type - Richard seemed ok with this approach).
We encode that this template type was generated from an auto by simply
adding $auto to the name which can be used for better diagnostics if needed.
- SemaLambda.h was added to hold some common lambda utility
functions (this file is likely to grow ...)
- Teach Sema::ActOnStartOfFunctionDef to check whether it
is being called to instantiate a generic lambda's call
operator, and if so, push an appropriately prepared
LambdaScopeInfo object on the stack.
- various tests were added - but much more will be needed.
There is obviously more work to be done, and both Richard (weakly) and Doug (strongly)
have requested that LambdaExpr be removed form the CXXRecordDecl LambdaDefinitionaData
in a future patch which is forthcoming.
A greatful thanks to all reviewers including Eli Friedman, James Dennett,
and especially the two gracious wizards (Richard Smith and Doug Gregor)
who spent hours providing feedback (in person in Chicago and on the mailing lists).
And yet I am certain that I have allowed unidentified bugs to creep in; bugs, that I will do my best to slay, once identified!
Thanks!
llvm-svn: 191453
Review: http://llvm-reviews.chandlerc.com/D1546.
I have picked up this patch form Lawrence
(http://llvm-reviews.chandlerc.com/D1063) and did a few changes.
From the original change description (updated as appropriate):
This patch adds a check that ensures that modules only use modules they
have so declared. To this end, it adds a statement on intended module
use to the module.map grammar:
use module-id
A module can then only use headers from other modules if it 'uses' them.
This enforcement is off by default, but may be turned on with the new
option -fmodules-decluse.
When enforcing the module semantics, we also need to consider a source
file part of a module. This is achieved with a compiler option
-fmodule-name=<module-id>.
The compiler at present only applies restrictions to the module directly
being built.
llvm-svn: 191283
When a comma occurs in a default argument or default initializer within a
class, disambiguate whether it is part of the initializer or whether it ends
the initializer.
The way this works (which I will be proposing for standardization) is to treat
the comma as ending the default argument or default initializer if the
following token sequence matches the syntactic constraints of a
parameter-declaration-clause or init-declarator-list (respectively).
This is both consistent with the disambiguation rules elsewhere (where entities
are treated as declarations if they can be), and should have no regressions
over our old behavior. I think it might also disambiguate all cases correctly,
but I don't have a proof of that.
There is an annoyance here: because we're performing a tentative parse in a
situation where we may not have seen declarations of all relevant entities (if
the comma is part of the initializer, lookup may find entites declared later in
the class), we need to turn off typo-correction and diagnostics during the
tentative parse, and in the rare case that we decide the comma is part of the
initializer, we need to revert all token annotations we performed while
disambiguating.
Any diagnostics that occur outside of the immediate context of the tentative
parse (for instance, if we trigger the implicit instantiation of a class
template) are *not* suppressed, mirroring the usual rules for a SFINAE context.
llvm-svn: 190639
With r190382, -Wunused-variable warns about unused const variables when
appropriate. For codebases that use -Werror, this poses a problem as
existing unused const variables need to be cleaned up first. To make the
transistion easier, this patch splits -Wunused-variable by pulling out
an additional -Wunused-const-variable (by default activated along with
-Wunused-variable).
llvm-svn: 190508
Make sure we perform the correct "referenced-but-not-used" check for
static member constants.
Fixes bug reported on cfe-commits by Alexey Samsonov.
llvm-svn: 190437
This patch does a few different things.
This patch improves unused var diags for const vars: we no longer
unconditionally suppress diagnostics for const vars, instead only suppressing
the diagnostic when the declaration appears to be useful.
This patch also makes us more consistently use whether a variable/function
is declared in the main file to suppress diagnostics where appropriate.
Fixes <rdar://problem/14907887>.
llvm-svn: 190382
Nico Weber