Index: ubsan.c
===================================================================
RCS file: /cvsroot/src/common/lib/libc/misc/ubsan.c,v
retrieving revision 1.5
diff -u -r1.5 ubsan.c
--- ubsan.c	13 Feb 2019 17:17:02 -0000	1.5
+++ ubsan.c	13 Apr 2019 14:52:17 -0000
@@ -232,6 +232,13 @@
 	struct CTypeDescriptor *mToType;
 };
 
+struct CImplicitConversionData {
+	struct CSourceLocation mLocation;
+	struct CTypeDescriptor *mFromType;
+	struct CTypeDescriptor *mToType;
+	uint8_t mKind;
+};
+
 /* Local utility functions */
 static void Report(bool isFatal, const char *pFormat, ...) __printflike(2, 3);
 static bool isAlreadyReported(struct CSourceLocation *pLocation);
@@ -255,6 +262,7 @@
 static const char *DeserializeTypeCheckKind(uint8_t hhuTypeCheckKind);
 static const char *DeserializeBuiltinCheckKind(uint8_t hhuBuiltinCheckKind);
 static const char *DeserializeCFICheckKind(uint8_t hhuCFICheckKind);
+static const char *DeserializeImplicitConversionCheckKind(uint8_t hhuImplicitConversionCheckKind);
 static bool isNegativeNumber(char *szLocation, struct CTypeDescriptor *pType, unsigned long ulNumber);
 static bool isShiftExponentTooLarge(char *szLocation, struct CTypeDescriptor *pType, unsigned long ulNumber, size_t zWidth);
 
@@ -307,6 +315,8 @@
 void __ubsan_handle_type_mismatch_v1_abort(struct CTypeMismatchData_v1 *pData, unsigned long ulPointer);
 void __ubsan_handle_vla_bound_not_positive(struct CVLABoundData *pData, unsigned long ulBound);
 void __ubsan_handle_vla_bound_not_positive_abort(struct CVLABoundData *pData, unsigned long ulBound);
+void __ubsan_handle_implicit_conversion(struct CImplicitConversionData *pData, unsigned long ulFrom, unsigned long ulTo);
+void __ubsan_handle_implicit_conversion_abort(struct CImplicitConversionData *pData, unsigned long ulFrom, unsigned long ulTo);
 void __ubsan_get_current_report_data(const char **ppOutIssueKind, const char **ppOutMessage, const char **ppOutFilename, uint32_t *pOutLine, uint32_t *pOutCol, char **ppOutMemoryAddr);
 
 static void HandleOverflow(bool isFatal, struct COverflowData *pData, unsigned long ulLHS, unsigned long ulRHS, const char *szOperation);
@@ -678,6 +688,26 @@
 	       szLocation, ulBase, ulResult);
 }
 
+static void
+HandleImplicitConversion(bool isFatal, struct CImplicitConversionData *pData, unsigned long ulFrom, unsigned long ulTo)
+{
+	char szLocation[LOCATION_MAXLEN];
+	char szFrom[NUMBER_MAXLEN];
+	char szTo[NUMBER_MAXLEN];
+
+	ASSERT(pData);
+
+	if (isAlreadyReported(&pData->mLocation))
+		return;
+
+	DeserializeLocation(szLocation, LOCATION_MAXLEN, &pData->mLocation);
+	DeserializeNumber(szLocation, szFrom, NUMBER_MAXLEN, pData->mFromType, ulFrom);
+	DeserializeNumber(szLocation, szTo, NUMBER_MAXLEN, pData->mToType, ulTo);
+
+	Report(isFatal, "UBSan: Undefined Behavior in %s, %s from %s %zu-bit %s (%s) to %s changed the value to %s %zu-bit %s\n",
+	       szLocation, DeserializeImplicitConversionCheckKind(pData->mKind), szFrom, zDeserializeTypeWidth(pData->mFromType), ISSET(pData->mFromType->mTypeInfo, NUMBER_SIGNED_BIT) ? "signed" : "unsigned", pData->mFromType->mTypeName, pData->mToType->mTypeName, szTo, zDeserializeTypeWidth(pData->mToType), ISSET(pData->mToType->mTypeInfo, NUMBER_SIGNED_BIT) ? "signed" : "unsigned");
+}
+
 /* Definions of public symbols emitted by the instrumentation code */
 void
 __ubsan_handle_add_overflow(struct COverflowData *pData, unsigned long ulLHS, unsigned long ulRHS)
@@ -1089,6 +1119,23 @@
 }
 
 void
+__ubsan_handle_implicit_conversion(struct CImplicitConversionData *pData, unsigned long ulFrom, unsigned long ulTo)
+{
+
+	ASSERT(pData);
+
+	HandleImplicitConversion(false, pData, ulFrom, ulTo);
+}
+
+void
+__ubsan_handle_implicit_conversion_abort(struct CImplicitConversionData *pData, unsigned long ulFrom, unsigned long ulTo)
+{
+	ASSERT(pData);
+
+	HandleImplicitConversion(true, pData, ulFrom, ulTo);
+}
+
+void
 __ubsan_get_current_report_data(const char **ppOutIssueKind, const char **ppOutMessage, const char **ppOutFilename, uint32_t *pOutLine, uint32_t *pOutCol, char **ppOutMemoryAddr)
 {
 	/*
@@ -1634,6 +1681,22 @@
 	return rgczCFICheckKinds[hhuCFICheckKind];
 }
 
+static const char *
+DeserializeImplicitConversionCheckKind(uint8_t hhuImplicitConversionCheckKind)
+{
+	const char *rgczImplicitConversionCheckKind[] = {
+		"integer truncation",			/* Not used since 2018 October 11th */
+		"unsigned integer truncation",
+		"signed integer truncation",
+		"integer sign change",
+		"signed integer trunctation or sign change",
+	};
+
+	ASSERT(__arraycount(rgczImplicitConversionCheckKind) > hhuImplicitConversionCheckKind);
+
+	return rgczImplicitConversionCheckKind[hhuImplicitConversionCheckKind];
+}
+
 static bool
 isNegativeNumber(char *szLocation, struct CTypeDescriptor *pType, unsigned long ulNumber)
 {