Use a typed comparison of floating point field values rather than just a string comparison.

This addresses toolchain issues; see http://code.google.com/p/android/issues/detail?id=994

tools/apicheck/src/com/android/apicheck/FieldInfo.java

@@ -66,6 +66,40 @@ public class FieldInfo {
         return parentQName + name();
     }
     
+    // Check the declared value with a typed comparison, not a string comparison,
+    // to accommodate toolchains with different fp -> string conversions.
+    public boolean valueEquals(FieldInfo other) {
+        // Type mismatch means nonequal, as does a null/non-null mismatch
+        if (!mType.equals(other.mType)
+                || ((mValue == null) != (other.mValue == null))) {
+            return false;
+        }
+
+        // Null values are considered equal
+        if (mValue == null) {
+            return true;
+        }
+
+        // Floating point gets an implementation-type comparison; all others just use the string
+        // If float/double parse fails, fall back to string comparison -- it means that it's a
+        // canonical droiddoc-generated constant expression that represents a NaN.
+        try {
+            if (mType.equals("float")) {
+                float val = Float.parseFloat(mValue);
+                float otherVal = Float.parseFloat(other.mValue);
+                return (val == otherVal);
+            } else if (mType.equals("double")) {
+                double val = Double.parseDouble(mValue);
+                double otherVal = Double.parseDouble(other.mValue);
+                return (val == otherVal);
+            }
+        } catch (NumberFormatException e) {
+            // fall through
+        }
+        
+        return mValue.equals(other.mValue);
+    }
+
     public boolean isConsistent(FieldInfo fInfo) {
       fInfo.mExistsInBoth = true;
       mExistsInBoth = true;
@@ -75,8 +109,8 @@ public class FieldInfo {
                   "Field " + fInfo.qualifiedName() + " has changed type");
           consistent = false;
       }
-      if ((mValue != null && !mValue.equals(fInfo.mValue)) || 
-          (mValue == null && fInfo.mValue != null)) {
+
+      if (!this.valueEquals(fInfo)) {
           Errors.error(Errors.CHANGED_VALUE, fInfo.position(),
                   "Field " + fInfo.qualifiedName() + " has changed value from "
                   + mValue + " to " + fInfo.mValue);