[APFloat] Add recoverable string parsing errors to APFloat

Implementing the APFloat part in PR4745. Differential Revision: https://reviews.llvm.org/D69770
llvm · Jan 6, 2020 · c5fb73c · c5fb73c
1 parent a792953
commit c5fb73c
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Showing 8 changed files with 256 additions and 196 deletions.
diff --git a/clang/lib/Lex/LiteralSupport.cpp b/clang/lib/Lex/LiteralSupport.cpp
@@ -1051,7 +1051,10 @@ NumericLiteralParser::GetFloatValue(llvm::APFloat &Result) {
     Str = Buffer;
   }
 
-  return Result.convertFromString(Str, APFloat::rmNearestTiesToEven);
+  auto StatusOrErr =
+      Result.convertFromString(Str, APFloat::rmNearestTiesToEven);
+  assert(StatusOrErr && "Invalid floating point representation");
+  return StatusOrErr ? *StatusOrErr : APFloat::opInvalidOp;
 }
 
 static inline bool IsExponentPart(char c) {

diff --git a/llvm/include/llvm/ADT/APFloat.h b/llvm/include/llvm/ADT/APFloat.h
@@ -38,6 +38,7 @@ class StringRef;
 class APFloat;
 class raw_ostream;
 
+template <typename T> class Expected;
 template <typename T> class SmallVectorImpl;
 
 /// Enum that represents what fraction of the LSB truncated bits of an fp number
@@ -299,7 +300,7 @@ class IEEEFloat final : public APFloatBase {
                                           bool, roundingMode);
   opStatus convertFromZeroExtendedInteger(const integerPart *, unsigned int,
                                           bool, roundingMode);
-  opStatus convertFromString(StringRef, roundingMode);
+  Expected<opStatus> convertFromString(StringRef, roundingMode);
   APInt bitcastToAPInt() const;
   double convertToDouble() const;
   float convertToFloat() const;
@@ -525,8 +526,8 @@ class IEEEFloat final : public APFloatBase {
                                         bool *) const;
   opStatus convertFromUnsignedParts(const integerPart *, unsigned int,
                                     roundingMode);
-  opStatus convertFromHexadecimalString(StringRef, roundingMode);
-  opStatus convertFromDecimalString(StringRef, roundingMode);
+  Expected<opStatus> convertFromHexadecimalString(StringRef, roundingMode);
+  Expected<opStatus> convertFromDecimalString(StringRef, roundingMode);
   char *convertNormalToHexString(char *, unsigned int, bool,
                                  roundingMode) const;
   opStatus roundSignificandWithExponent(const integerPart *, unsigned int, int,
@@ -648,7 +649,7 @@ class DoubleAPFloat final : public APFloatBase {
   cmpResult compare(const DoubleAPFloat &RHS) const;
   bool bitwiseIsEqual(const DoubleAPFloat &RHS) const;
   APInt bitcastToAPInt() const;
-  opStatus convertFromString(StringRef, roundingMode);
+  Expected<opStatus> convertFromString(StringRef, roundingMode);
   opStatus next(bool nextDown);
 
   opStatus convertToInteger(MutableArrayRef<integerPart> Input,
@@ -1108,7 +1109,7 @@ class APFloat : public APFloatBase {
     APFLOAT_DISPATCH_ON_SEMANTICS(
         convertFromZeroExtendedInteger(Input, InputSize, IsSigned, RM));
   }
-  opStatus convertFromString(StringRef, roundingMode);
+  Expected<opStatus> convertFromString(StringRef, roundingMode);
   APInt bitcastToAPInt() const {
     APFLOAT_DISPATCH_ON_SEMANTICS(bitcastToAPInt());
   }

diff --git a/llvm/lib/MC/MCParser/AsmParser.cpp b/llvm/lib/MC/MCParser/AsmParser.cpp
@@ -3130,8 +3130,7 @@ bool AsmParser::parseRealValue(const fltSemantics &Semantics, APInt &Res) {
       Value = APFloat::getNaN(Semantics, false, ~0);
     else
       return TokError("invalid floating point literal");
-  } else if (Value.convertFromString(IDVal, APFloat::rmNearestTiesToEven) ==
-             APFloat::opInvalidOp)
+  } else if (!Value.convertFromString(IDVal, APFloat::rmNearestTiesToEven))
     return TokError("invalid floating point literal");
   if (IsNeg)
     Value.changeSign();