From cd466442549b9b485c3e0f84a13b60f69ced8ad3 Mon Sep 17 00:00:00 2001
From: Bryan Tam <bryan.tam@mail.utoronto.ca>
Date: Mon, 29 Jan 2018 16:38:00 -0700
Subject: [PATCH] Handle Float Literal using BigDecimal

---
 include/swift/WALASupport/WALAWalker.h  |  2 ++
 lib/WALASupport/InstrKindInfoGetter.cpp | 22 ++++++++++++++++++----
 lib/WALASupport/WALAWalker.cpp          | 15 +++++++++++++++
 3 files changed, 35 insertions(+), 4 deletions(-)

diff --git a/include/swift/WALASupport/WALAWalker.h b/include/swift/WALASupport/WALAWalker.h
index ed20d7aec6d9d..45e01068807e0 100644
--- a/include/swift/WALASupport/WALAWalker.h
+++ b/include/swift/WALASupport/WALAWalker.h
@@ -55,6 +55,8 @@ class WALAIntegration {
   void print(jobject obj);
   
   jobject makePosition(int, int, int, int);
+
+  jobject makeBigDecimal(const char *, int);
   
   WALAIntegration(JNIEnv *, Exceptions &, const char *);
 };
diff --git a/lib/WALASupport/InstrKindInfoGetter.cpp b/lib/WALASupport/InstrKindInfoGetter.cpp
index abbc04f3ed9ff..232b6fec6569b 100644
--- a/lib/WALASupport/InstrKindInfoGetter.cpp
+++ b/lib/WALASupport/InstrKindInfoGetter.cpp
@@ -229,12 +229,26 @@ jobject InstrKindInfoGetter::handleFloatLiteralInst() {
   if (outs != NULL) {
     *outs << "<< FloatLiteralInst >>" << "\n";
   }
+  jobject node = nullptr;
   FloatLiteralInst* castInst = cast<FloatLiteralInst>(instr);
   APFloat value = castInst->getValue();
-  bool APFLosesInfo;
-  value.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &APFLosesInfo);
-  jobject node = (*wala)->makeConstant(value.convertToDouble());
-  nodeMap->insert(std::make_pair(castInst, node));
+
+  if (value.isFinite()) {
+    // To BigDecimal
+    SmallVector<char, 128> buf;
+    value.toString(buf);
+    jobject bigDecimal = (*wala).makeBigDecimal(buf.data(), buf.size());
+    node = (*wala)->makeConstant(bigDecimal);
+    nodeMap->insert(std::make_pair(castInst, node));
+  } 
+  else {
+    // Infinity of NaN, convert to double 
+    // as BigDecimal constructor cannot accept strings of these
+    bool APFLosesInfo;
+    value.convert(APFloat::IEEEdouble(), APFloat::rmNearestTiesToEven, &APFLosesInfo);
+    node = (*wala)->makeConstant(value.convertToDouble());
+    nodeMap->insert(std::make_pair(castInst, node));
+  }
   return node;
 }
 
diff --git a/lib/WALASupport/WALAWalker.cpp b/lib/WALASupport/WALAWalker.cpp
index 803ae1620220a..10ab1aa491fab 100644
--- a/lib/WALASupport/WALAWalker.cpp
+++ b/lib/WALASupport/WALAWalker.cpp
@@ -54,6 +54,21 @@ jobject WALAIntegration::makePosition(int fl, int fc, int ll, int lc) {
 	return result;
 }
 
+jobject WALAIntegration::makeBigDecimal(const char *strData, int strLen) {
+	char *safeData = strndup(strData, strLen);
+	jobject val = java_env->NewStringUTF(safeData);
+	delete safeData;
+	jclass bigDecimalCls = java_env->FindClass("java/math/BigDecimal");
+	THROW_ANY_EXCEPTION(cpp_ex);
+	jmethodID bigDecimalInit = java_env->GetMethodID(bigDecimalCls, 
+		"<init>", "(Ljava/lang/String;)V");
+	THROW_ANY_EXCEPTION(cpp_ex);
+	jobject bigDecimal = java_env->NewObject(bigDecimalCls, bigDecimalInit, val);
+	THROW_ANY_EXCEPTION(cpp_ex);
+	java_env->DeleteLocalRef(val);
+	return bigDecimal;
+}
+
 void WALAIntegration::print(jobject obj) {
 	print_object(java_env, obj);
 	THROW_ANY_EXCEPTION(cpp_ex);