Added optional pass-by-reference argument "isExact" to

NumericLiteralParser::GetFloatValue(). Upon method return, this flag has the value
true if the returned APFloat can exactly represent the number in the parsed text,
and false otherwise.

Modified the implementation of GetFloatValue() to parse literals using APFloat's
convertFromString method (which allows us to set the value of isExact).

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@44339 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/Lex/LiteralSupport.cpp b/Lex/LiteralSupport.cpp
index 21ead21bfece4adafe06f2fc2ed2bae22a8ce1bf..ebc66271dbd36409ad278592a84b8ba9f585ff87 100644 (file)
--- a/Lex/LiteralSupport.cpp
+++ b/Lex/LiteralSupport.cpp
@@ -410,17 +410,27 @@ bool NumericLiteralParser::GetIntegerValue(llvm::APInt &Val) {
 }
 
 llvm::APFloat NumericLiteralParser::
-GetFloatValue(const llvm::fltSemantics &Format) {
+GetFloatValue(const llvm::fltSemantics &Format, bool* isExact) {
+  using llvm::APFloat;
+  
   char floatChars[256];
   strncpy(floatChars, ThisTokBegin, ThisTokEnd-ThisTokBegin);
   floatChars[ThisTokEnd-ThisTokBegin] = '\0';
-#if 0
-  // This doesn't work yet.
-  return llvm::APFloat(Format, floatChars);
+
+#if 1
+  APFloat V (Format, APFloat::fcZero, false);
+
+  APFloat::opStatus status;
+  status = V.convertFromString(floatChars,APFloat::rmTowardZero);
+  
+  if (isExact)
+    *isExact = status == APFloat::opOK;
+  
+  return V;
 #else
   // FIXME: this is horrible!
-  llvm::APFloat V(strtod(floatChars, 0));
-  V.convert(Format, llvm::APFloat::rmTowardZero);
+  APFloat V(strtod(floatChars, 0));
+  V.convert(Format, APFloat::rmTowardZero);
   return V;
 #endif
 }

diff --git a/include/clang/Lex/LiteralSupport.h b/include/clang/Lex/LiteralSupport.h
index e8650fc8fa70139e1355329ce4a4729cc458feb6..2555660076900f2fee36b4454bbba1bba00a5dbf 100644 (file)
--- a/include/clang/Lex/LiteralSupport.h
+++ b/include/clang/Lex/LiteralSupport.h
@@ -77,8 +77,11 @@ public:
   
   /// GetFloatValue - Convert this numeric literal to a floating value, using
   /// the specified APFloat fltSemantics (specifying float, double, etc).
-  ///
-  llvm::APFloat GetFloatValue(const llvm::fltSemantics &Format);
+  /// The optional bool isExact (passed-by-reference) has its value
+  /// set to true if the returned APFloat can represent the number in the
+  /// literal exactly, and false otherwise.
+  llvm::APFloat GetFloatValue(const llvm::fltSemantics &Format, 
+                              bool* isExact = NULL);
 
 private:  
   void Diag(SourceLocation Loc, unsigned DiagID,