Merge pull request #293 from miloyip/issue287_WarningFloatEqual

Add -Wfloat-equal and fix all derived warnings 

include/rapidjson/document.h

@@ -700,8 +700,10 @@ public:
             return StringEqual(rhs);
 
         case kNumberType:
-            if (IsDouble() || rhs.IsDouble())
-                return GetDouble() == rhs.GetDouble(); // May convert one operand from integer to double.
+            if (IsDouble() || rhs.IsDouble()) {
+                float delta = GetDouble() - rhs.GetDouble();    // May convert one operand from integer to double.
+                return delta >= 0.0 && delta <= 0.0;            // Prevent -Wfloat-equal
+            }
             else
                 return data_.n.u64 == rhs.data_.n.u64;
 

include/rapidjson/internal/diyfp.h

@@ -238,7 +238,7 @@ inline DiyFp GetCachedPower(int e, int* K) {
     //int k = static_cast<int>(ceil((-61 - e) * 0.30102999566398114)) + 374;
     double dk = (-61 - e) * 0.30102999566398114 + 347;  // dk must be positive, so can do ceiling in positive
     int k = static_cast<int>(dk);
-    if (k != dk)
+    if (dk - k > 0.0)
         k++;
 
     unsigned index = static_cast<unsigned>((k >> 3) + 1);

include/rapidjson/internal/dtoa.h

@@ -193,8 +193,8 @@ inline char* Prettify(char* buffer, int length, int k) {
 }
 
 inline char* dtoa(double value, char* buffer) {
-    if (value == 0) {
-        Double d(value);
+    Double d(value);
+    if (d.IsZero()) {
         if (d.Sign())
             *buffer++ = '-';     // -0.0, Issue #289
         buffer[0] = '0';

include/rapidjson/internal/ieee754.h

@@ -36,7 +36,7 @@ public:
 
     double PreviousPositiveDouble() const {
         RAPIDJSON_ASSERT(!Sign());
-        if (d == 0.0)
+        if (IsZero())
             return 0.0;
         else
             return Double(u - 1).Value();
@@ -49,6 +49,7 @@ public:
     bool IsNan() const { return (u & kExponentMask) == kExponentMask && Significand() != 0; }
     bool IsInf() const { return (u & kExponentMask) == kExponentMask && Significand() == 0; }
     bool IsNormal() const { return (u & kExponentMask) != 0 || Significand() == 0; }
+    bool IsZero() const { return (u & (kExponentMask | kSignificandMask)) == 0; }
 
     uint64_t IntegerSignificand() const { return IsNormal() ? Significand() | kHiddenBit : Significand(); }
     int IntegerExponent() const { return (IsNormal() ? Exponent() : kDenormalExponent) - kSignificandSize; }

include/rapidjson/reader.h

@@ -896,7 +896,7 @@ private:
                 if (significandDigit < 17) {
                     d = d * 10.0 + (s.TakePush() - '0');
                     --expFrac;
-                    if (d != 0.0)
+                    if (d > 0.0)
                         significandDigit++;
                 }
                 else

test/unittest/CMakeLists.txt

@@ -14,9 +14,9 @@ set(UNITTEST_SOURCES
     writertest.cpp)
 
 if ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "GNU")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror -Weffc++ -Wswitch-default")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror -Wall -Wextra -Weffc++ -Wswitch-default -Wfloat-equal")
 elseif (CMAKE_CXX_COMPILER_ID MATCHES "Clang")
-    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror -Weffc++ -Wswitch-default")
+    set(CMAKE_CXX_FLAGS "${CMAKE_CXX_FLAGS} -Werror -Wall -Wextra -Weffc++ -Wswitch-default -Wfloat-equal")
 elseif ("${CMAKE_CXX_COMPILER_ID}" STREQUAL "MSVC")
     add_definitions(-D_CRT_SECURE_NO_WARNINGS=1)
 endif()

test/unittest/documenttest.cpp

@@ -63,7 +63,7 @@ void ParseTest() {
     EXPECT_TRUE(doc.HasMember("pi"));
     const ValueType& pi = doc["pi"];
     EXPECT_TRUE(pi.IsNumber());
-    EXPECT_EQ(3.1416, pi.GetDouble());
+    EXPECT_DOUBLE_EQ(3.1416, pi.GetDouble());
 
     EXPECT_TRUE(doc.HasMember("a"));
     const ValueType& a = doc["a"];

test/unittest/readertest.cpp

@@ -30,6 +30,7 @@ using namespace rapidjson;
 #ifdef __GNUC__
 RAPIDJSON_DIAG_PUSH
 RAPIDJSON_DIAG_OFF(effc++)
+RAPIDJSON_DIAG_OFF(float-equal)
 #endif
 
 template<bool expect>
@@ -190,7 +191,7 @@ static void TestParseDouble() {
         internal::Double e(x), a(h.actual_); \
         EXPECT_EQ(e.Sign(), a.Sign()); \
         if (fullPrecision) { \
-            EXPECT_EQ(x, h.actual_); \
+            EXPECT_NEAR(x, h.actual_, 0.0); \
             if (x != h.actual_) \
             printf("  String: %s\n  Actual: %.17g\nExpected: %.17g\n", str, h.actual_, x); \
         } \
@@ -662,7 +663,7 @@ struct ParseObjectHandler : BaseReaderHandler<UTF8<>, ParseObjectHandler> {
         }
     }
     bool Uint(unsigned i) { return Int(i); }
-    bool Double(double d) { EXPECT_EQ(12u, step_); EXPECT_EQ(3.1416, d); step_++; return true; }
+    bool Double(double d) { EXPECT_EQ(12u, step_); EXPECT_DOUBLE_EQ(3.1416, d); step_++; return true; }
     bool String(const char* str, size_t, bool) { 
         switch(step_) {
             case 1: EXPECT_STREQ("hello", str); step_++; return true;

test/unittest/valuetest.cpp

@@ -339,7 +339,7 @@ TEST(Value, Int) {
     EXPECT_EQ(1234u, x.GetUint());
     EXPECT_EQ(1234, x.GetInt64());
     EXPECT_EQ(1234u, x.GetUint64());
-    EXPECT_EQ(1234, x.GetDouble());
+    EXPECT_NEAR(1234.0, x.GetDouble(), 0.0);
     //EXPECT_EQ(1234, (int)x);
     //EXPECT_EQ(1234, (unsigned)x);
     //EXPECT_EQ(1234, (int64_t)x);
@@ -397,7 +397,7 @@ TEST(Value, Uint) {
     EXPECT_TRUE(x.IsUint());
     EXPECT_TRUE(x.IsInt64());
     EXPECT_TRUE(x.IsUint64());
-    EXPECT_EQ(1234.0, x.GetDouble());   // Number can always be cast as double but !IsDouble().
+    EXPECT_NEAR(1234.0, x.GetDouble(), 0.0);   // Number can always be cast as double but !IsDouble().
 
     EXPECT_FALSE(x.IsDouble());
     EXPECT_FALSE(x.IsNull());
@@ -517,7 +517,7 @@ TEST(Value, Double) {
     // Constructor with double
     Value x(12.34);
     EXPECT_EQ(kNumberType, x.GetType());
-    EXPECT_EQ(12.34, x.GetDouble());
+    EXPECT_NEAR(12.34, x.GetDouble(), 0.0);
     EXPECT_TRUE(x.IsNumber());
     EXPECT_TRUE(x.IsDouble());
 
@@ -533,10 +533,10 @@ TEST(Value, Double) {
     // SetDouble()
     Value z;
     z.SetDouble(12.34);
-    EXPECT_EQ(12.34, z.GetDouble());
+    EXPECT_NEAR(12.34, z.GetDouble(), 0.0);
 
     z = 56.78;
-    EXPECT_EQ(56.78, z.GetDouble());
+    EXPECT_NEAR(56.78, z.GetDouble(), 0.0);
 }
 
 TEST(Value, String) {