https://reviews.llvm.org/D131255 (82afc9b169)
began warning about conversion causing data loss for a single-bit
bit-field. However, after landing the changes, there were reports about
significant false positives from some code bases.
This alters the approach taken in that patch by introducing a new
warning group (-Wsingle-bit-bitfield-constant-conversion) which is
grouped under -Wbitfield-constant-conversion to allow users to
selectively disable the single-bit warning without losing the other
constant conversion warnings.
Differential Revision: https://reviews.llvm.org/D132851
A one-bit signed bit-field can only hold the values 0 and -1; this
corrects the diagnostic behavior accordingly.
Fixes#53253
Differential Revision: https://reviews.llvm.org/D131255
A significant number of our tests in C accidentally use functions
without prototypes. This patch converts the function signatures to have
a prototype for the situations where the test is not specific to K&R C
declarations. e.g.,
void func();
becomes
void func(void);
This is the second batch of tests being updated (there are a significant
number of other tests left to be updated).
Summary:
The diagnostic did not handle ~ well. An expression such as ~0 is often used when 'all ones' is needed.
Differential Revision: https://reviews.llvm.org/D24232
llvm-svn: 282156
Silence the -Wbitfield-constant-conversion warning for when -1 or other
negative values are assigned to unsigned bitfields, provided that the bitfield
is wider than the minimum number of bits needed to encode the negative value.
llvm-svn: 277796
Sometimes, char arrays are used as bit storage, with no difference made between
signed and unsigned char. Thus, it is reasonable to use 0 to 255 instead of
-128 to 127 and not trigger this warning.
llvm-svn: 259947
Switch the evaluation from isIntegerConstantExpr to EvaluateAsInt.
EvaluateAsInt will evaluate more types of expressions than
isIntegerConstantExpr.
Move one case from -Wsign-conversion to -Wconstant-conversion. The case is:
1) Source and target types are signed
2) Source type is wider than the target type
3) The source constant value is positive
4) The conversion will store the value as negative in the target.
llvm-svn: 259271
likely be implicitly truncated:
* All forms of Bitwise-and, bitwise-or, and integer multiplication.
* The assignment form of integer addition, subtraction, and exclusive-or
* The RHS of the comma operator
* The LHS of left shifts.
llvm-svn: 178273
of the enumerators rather than the actual expressible range. This is
great when dealing with opaque *values* of that type, but when computing
the range of the type for purposes of converting *into* it, it produces
warnings in cases we don't care about (e.g. enum_t x = 500;). Divide
the logic into these two cases and use the more conservative range for
targets.
llvm-svn: 118735
own subcategory, -Wconstant-conversion, which is on by default.
Tweak the constant folder to give better results in the invalid
case of a negative shift amount.
Implements rdar://problem/6792488
llvm-svn: 118636
Aaron Ballman