[PATCH] D42728: Add more warnings for implict conversions (e.g. double truncation to float).

[Andrew V. Tischenko via Phabricator via llvm-commits]

avt77 added inline comments.


================
Comment at: lib/Sema/SemaChecking.cpp:9222
+  const BuiltinType *SourceBT = dyn_cast<BuiltinType>(
+      S.Context.getCanonicalType(E->getRHS()->getType()).getTypePtr());
+  const BuiltinType *TargetBT =
----------------
rjmccall wrote:
> `E->getComputationResultType()->getType()->getAs<BuiltinType>()`
Unfortunatelly, it does not work because getComputationResultType() returns 'double':

CompoundAssignOperator 0xd2db9a0 'float' '+=' ComputeLHSTy='double' ComputeResultTy='double'
|-UnaryOperator 0xd2db940 'float' lvalue prefix '*' cannot overflow
| `-ImplicitCastExpr 0xd2db928 'float *' <LValueToRValue>
|   `-DeclRefExpr 0xd2db900 'float *' lvalue ParmVar 0xd2db780 'b' 'float *'
`-ImplicitCastExpr 0xd2db988 'double' <LValueToRValue>
  `-DeclRefExpr 0xd2db960 'double' lvalue ParmVar 0xd2db6d8 'a' 'double'

(gdb) p CAOp->getComputationLHSType()->dump()
BuiltinType 0xd25a9b0 'double'

(gdb) p CAOp->getComputationResultType ()->dump()
BuiltinType 0xd25a9b0 'double'



https://reviews.llvm.org/D42728