Enhance the diagnostic for literal float -> int conversions to suggest
rewriting the literal when the value is integral. It is not uncommon to
see code written as:
const int kBigNumber = 42e5;
Without any real awareness that this is no longer an ICE. The note helps
automate and ease the process of fixing code that violates the warning.
git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@129243 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Sema/SemaChecking.cpp b/lib/Sema/SemaChecking.cpp
index e1adfd4..9372a16 100644
--- a/lib/Sema/SemaChecking.cpp
+++ b/lib/Sema/SemaChecking.cpp
@@ -2763,6 +2763,38 @@
DiagnoseImpCast(S, E, E->getType(), T, CContext, diag);
}
+/// Diagnose an implicit cast from a literal expression. Also attemps to supply
+/// fixit hints when the cast wouldn't lose information to simply write the
+/// expression with the expected type.
+void DiagnoseFloatingLiteralImpCast(Sema &S, FloatingLiteral *FL, QualType T,
+ SourceLocation CContext) {
+ // Emit the primary warning first, then try to emit a fixit hint note if
+ // reasonable.
+ S.Diag(FL->getExprLoc(), diag::warn_impcast_literal_float_to_integer)
+ << FL->getType() << T << FL->getSourceRange() << SourceRange(CContext);
+
+ const llvm::APFloat &Value = FL->getValue();
+
+ // Don't attempt to fix PPC double double literals.
+ if (&Value.getSemantics() == &llvm::APFloat::PPCDoubleDouble)
+ return;
+
+ // Try to convert this exactly to an 64-bit integer. FIXME: It would be
+ // nice to support arbitrarily large integers here.
+ bool isExact = false;
+ uint64_t IntegerPart;
+ if (Value.convertToInteger(&IntegerPart, 64, /*isSigned=*/true,
+ llvm::APFloat::rmTowardZero, &isExact)
+ != llvm::APFloat::opOK || !isExact)
+ return;
+
+ llvm::APInt IntegerValue(64, IntegerPart, /*isSigned=*/true);
+
+ std::string LiteralValue = IntegerValue.toString(10, /*isSigned=*/true);
+ S.Diag(FL->getExprLoc(), diag::note_fix_integral_float_as_integer)
+ << FixItHint::CreateReplacement(FL->getSourceRange(), LiteralValue);
+}
+
std::string PrettyPrintInRange(const llvm::APSInt &Value, IntRange Range) {
if (!Range.Width) return "0";
@@ -2776,7 +2808,7 @@
SourceManager &smgr = S.Context.getSourceManager();
return loc.isMacroID() && smgr.isInSystemHeader(smgr.getSpellingLoc(loc));
}
-
+
void CheckImplicitConversion(Sema &S, Expr *E, QualType T,
SourceLocation CC, bool *ICContext = 0) {
if (E->isTypeDependent() || E->isValueDependent()) return;
@@ -2859,9 +2891,8 @@
return;
Expr *InnerE = E->IgnoreParenImpCasts();
- if (FloatingLiteral *LiteralExpr = dyn_cast<FloatingLiteral>(InnerE)) {
- DiagnoseImpCast(S, LiteralExpr, T, CC,
- diag::warn_impcast_literal_float_to_integer);
+ if (FloatingLiteral *FL = dyn_cast<FloatingLiteral>(InnerE)) {
+ DiagnoseFloatingLiteralImpCast(S, FL, T, CC);
} else {
DiagnoseImpCast(S, E, T, CC, diag::warn_impcast_float_integer);
}