Also relax unreachable 'break' and 'return' to not check for being
preceded by a call to 'noreturn'. That turns out to not be so
interesting in practice.
llvm-svn: 204000
Recent work on -Wunreachable-code has focused on suppressing uninteresting
unreachable code that center around "configuration values", but
there are still some set of cases that are sometimes interesting
or uninteresting depending on the codebase. For example, a dead
"break" statement may not be interesting for a particular codebase,
potentially because it is auto-generated or simply because code
is written defensively.
To address these workflow differences, -Wunreachable-code is now
broken into several diagnostic groups:
-Wunreachable-code: intended to be a reasonable "default" for
most users.
and then other groups that turn on more aggressive checking:
-Wunreachable-code-break: warn about dead break statements
-Wunreachable-code-trivial-return: warn about dead return statements
that return "trivial" values (e.g., return 0). Other return
statements that return non-trivial values are still reported
under -Wunreachable-code (this is an area subject to more refinement).
-Wunreachable-code-aggressive: supergroup that enables all these
groups.
The goal is to eventually make -Wunreachable-code good enough to
either be in -Wall or on-by-default, thus finessing these warnings
into different groups helps achieve maximum signal for more users.
TODO: the tests need to be updated to reflect this extra control
via diagnostic flags.
llvm-svn: 203994
This can possibly be refined later, but right now the experience
is so incomprehensible for a user to understand what is going on
this isn't a useful warning.
llvm-svn: 203336
This patch fixes PR18964. In linkage computation, assertion fails when
an old invalid declaration's linkage mismatches with the current
decl's one.
llvm-svn: 203168
I have mixed feelings about this one. It's used all over the codebase,
and is analogous to the current heuristic for ordinary C string literals.
This requires some ad hoc pattern matching of the AST. While the
test case mirrors what we see std::string in libc++, it's not really
testing the libc++ headers.
llvm-svn: 203091
Sometimes do..while() is used to create a scope that can be left early.
In such cases, the unreachable 'while()' test is not usually interesting
unless it actually does something that is observable.
llvm-svn: 203051
Summary:
This is needed to allow MSVC's <atomic> header to properly parse.
It uses _Atomic as a class-id.
Reviewers: rnk
Reviewed By: rnk
CC: cfe-commits
Differential Revision: http://llvm-reviews.chandlerc.com/D2948
llvm-svn: 202901
const char *format = "%s";
std::experimental::string_view view = "foo";
printf(format, view);
In this case, not only warn about a class type being used here, but also suggest that calling c_str() might be a good idea.
llvm-svn: 202461
or virtual functions, but permit that error to be downgraded to
a warning (with -Wno-error=incompatible-ms-struct), and officially
support this kind of dual, ABI-mixing layout.
The basic problem here is that projects which use ms_struct are often
not very circumspect about what types they annotate; for example,
some projects enable the pragma in a prefix header and then only
selectively disable it around system header inclusions. They may
only care about binary compatibility with MSVC for a subset of
those structs, but that doesn't mean they have no binary
compatibility concerns at all for the rest; thus we are essentially
forced into supporting this hybrid ABI. But it's reasonable for
us to at least point out the places where we're not making
any guarantees.
The original diagnostic was for dynamic classes, i.e. those with
virtual functions or virtual bases; I've extended it to include
all classes with bases, because we are not actually making any
attempt to duplicate MSVC's base subobject layout in ms_struct
(and it is indeed quite different from Itanium, even for
non-virtual bases).
rdar://16178895
llvm-svn: 202427
null comparison when the pointer is known to be non-null.
This catches the array to pointer decay, function to pointer decay and
address of variables. This does not catch address of function since this
has been previously used to silence a warning.
Pointer to bool conversion is under -Wbool-conversion.
Pointer to null comparison is under -Wtautological-pointer-compare, a sub-group
of -Wtautological-compare.
void foo() {
int arr[5];
int x;
// warn on these conditionals
if (foo);
if (arr);
if (&x);
if (foo == null);
if (arr == null);
if (&x == null);
if (&foo); // no warning
}
llvm-svn: 202216
The warnings fall into three groups.
1) Using an absolute value function of the wrong type, for instance, using the
int absolute value function when the argument is a floating point type.
2) Using the improper sized absolute value function, for instance, using abs
when the argument is a long long. llabs should be used instead.
From these two cases, an implicit conversion will occur which may cause
unexpected behavior. Where possible, suggest the proper absolute value
function to use, and which header to include if the function is not available.
3) Taking the absolute value of an unsigned value. In addition to this warning,
suggest to remove the function call. This usually indicates a logic error
since the programmer assumed negative values would have been possible.
llvm-svn: 202211
- Don't emit anything when we encounter a call to a conversion operator.
"bar(a & b)" instead of "bar(a & b.operator int())"
This preserves the semantics and is still idempotent if we print the AST multiple times.
- Properly print declarations of conversion operators.
"explicit operator bool();" instead of "bool operator _Bool();"
PR18776.
llvm-svn: 202167
We were previously checking at every destructor declaration, but that was a bit
excessive. Since the deleting destructor is emitted with the vtable, do the
check when the vtable is marked used.
Differential Revision: http://llvm-reviews.chandlerc.com/D2851
llvm-svn: 202046
DR18 previously forebode typedefs to be used as parameter types if they
were of type 'void'. DR577 allows 'void' to be used as a function
parameter type regardless from where it came.
llvm-svn: 201631
The following attributes have been (silently) deprecated, with their replacements listed:
lockable => capability
exclusive_locks_required => requires_capability
shared_locks_required => requires_shared_capability
locks_excluded => requires_capability
There are no functional changes intended.
llvm-svn: 201585
temporary in a decltype expression only applies if that temporary was created
by a function call, not by a function-style cast or other flavour of
expression.
llvm-svn: 201542
For some reason we have two bits of code handling this printing:
lib/AST/Decl.cpp: OS << "<anonymous namespace>";
lib/AST/TypePrinter.cpp: OS << "<anonymous namespace>::";
it would be nice if we only had one...
llvm-svn: 201437
and the class name is shadowed by another member. Recovery still needs
to be figured out, which is non-trivial since the parser has already gone
down a much different path than if it had recognized the class template
as type instead of seeing the member that shadowed the class template.
llvm-svn: 201360
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
Richard Smith