These are intended to mimic warnings available in gcc.
-Wunused-but-set-variable is triggered in the case of a variable which
appears on the LHS of an assignment but not otherwise used.
For instance:
void f() {
int x;
x = 0;
}
-Wunused-but-set-parameter works similarly, but for function parameters
instead of variables.
In C++, they are triggered only for scalar types; otherwise, they are
triggered for all types. This is gcc's behavior.
-Wunused-but-set-parameter is controlled by -Wextra, while
-Wunused-but-set-variable is controlled by -Wunused. This is slightly
different from gcc's behavior, but seems most consistent with clang's
behavior for -Wunused-parameter and -Wunused-variable.
Reviewed By: aeubanks
Differential Revision: https://reviews.llvm.org/D100581
Without this patch, APSInt inherits APInt::isNegative, which merely
checks the sign bit without regard to whether the type is actually
signed. isNonNegative and isStrictlyPositive call isNegative and so
are also affected.
This patch adjusts APSInt to override isNegative, isNonNegative, and
isStrictlyPositive with implementations that consider whether the type
is signed.
A large set of Clang OpenMP tests are affected. Without this patch,
these tests assume that `true` is not a valid argument for clauses
like `collapse`. Indeed, `true` fails APInt::isStrictlyPositive but
not APSInt::isStrictlyPositive. This patch adjusts those tests to
assume `true` should be accepted.
This patch also adds tests revealing various other similar fixes due
to APSInt::isNegative calls in Clang's ExprConstant.cpp and
SemaExpr.cpp: `++` and `--` overflow in `constexpr`, evaluated object
size based on `alloc_size`, `<<` and `>>` shift count validation, and
OpenMP array section validation.
Reviewed By: lebedev.ri, ABataev, hfinkel
Differential Revision: https://reviews.llvm.org/D59712
llvm-svn: 359012
This fixes an error in type checking of shift of vector values.
Patch by Vladimir Yakovlev.
Differential Revision: https://reviews.llvm.org/D21678
llvm-svn: 278501
a subprocess invocation which is pretty significant on Windows. It also
likely saves a bunch of thrashing the host machine needlessly. Finally
it makes the tests much more predictable and less dependent on the host.
For example 'header_lookup1.c' was passing '-fno-ms-extensions' just to
thwart the host detection adding it into the compilation. By runnig CC1
directly we don't have to deal with such oddities.
llvm-svn: 199308
Change the output for -Wshift-overflow and
-Wshift-sign-overflow to an unsigned hexadecimal. It makes
more sense for looking at bits than a signed decimal does.
Also, change the diagnostic's wording from "overrides"
to "sets".
This uses a new optional argument in APInt::toString()
that adds the '0x' prefix to hexademical numbers.
This fixes PR 9651.
Patch by nobled@dreamwidth.org!
llvm-svn: 133033
expressions. Consider the code:
int64_t i = 10 << 30;
This compiles fine, but most developers expect it to produce the value
for 10 gigs, not -2 gigs. This is actually undefined behavior because
the LHS is a signed integer type.
The warning is currently gated behind -Wshift-overflow.
There is a special case where only the sign bit is overridden that gets
a custom error message and is by default ignored. This case is much less
likely to cause observed buggy behavior, it's just undefined behavior
according to the spec. This warning can be enabled with
-Wshift-sign-overflow.
Original patch by Oleg Slezberg, with style tweaks and some correctness
fixes by me.
llvm-svn: 126342
Michael Benfield