Sema: show shift result in hexadecimal
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!
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@133033 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaExpr.cpp b/lib/Sema/SemaExpr.cpp
index 91821fb..9f9c052 100644
--- a/lib/Sema/SemaExpr.cpp
+++ b/lib/Sema/SemaExpr.cpp
@@ -7394,19 +7394,24 @@
llvm::APSInt Result = Left.extend(ResultBits.getLimitedValue());
Result = Result.shl(Right);
+ // Print the bit representation of the signed integer as an unsigned
+ // hexadecimal number.
+ llvm::SmallString<40> HexResult;
+ Result.toString(HexResult, 16, /*Signed =*/false, /*Literal =*/true);
+
// If we are only missing a sign bit, this is less likely to result in actual
// bugs -- if the result is cast back to an unsigned type, it will have the
// expected value. Thus we place this behind a different warning that can be
// turned off separately if needed.
if (LeftBits == ResultBits - 1) {
- S.Diag(Loc, diag::warn_shift_result_overrides_sign_bit)
- << Result.toString(10) << LHSTy
+ S.Diag(Loc, diag::warn_shift_result_sets_sign_bit)
+ << HexResult.str() << LHSTy
<< lex.get()->getSourceRange() << rex.get()->getSourceRange();
return;
}
S.Diag(Loc, diag::warn_shift_result_gt_typewidth)
- << Result.toString(10) << Result.getMinSignedBits() << LHSTy
+ << HexResult.str() << Result.getMinSignedBits() << LHSTy
<< Left.getBitWidth() << lex.get()->getSourceRange() << rex.get()->getSourceRange();
}