From 94e6f00da9685bfee5ec89bbf7a455edd0fe0348 Mon Sep 17 00:00:00 2001
From: Xuejun Yang <jxyang@cs.utah.edu>
Date: Mon, 20 Jun 2011 19:00:21 -0600
Subject: [PATCH] fix a bug in analyzing effect conflicts between union fields

This fixes the runtime crash seen for seed 655329422
---
 src/Effect.cpp | 42 ++++++++++++++++++++++++------------------
 src/Effect.h   |  4 ++--
 2 files changed, 26 insertions(+), 20 deletions(-)

diff --git a/src/Effect.cpp b/src/Effect.cpp
index 9543fcda2..99f1145d8 100644
--- a/src/Effect.cpp
+++ b/src/Effect.cpp
@@ -438,33 +438,39 @@ Effect::field_is_written(const Variable *v) const
 }
 
 bool
-Effect::sibling_field_is_read(const Variable *v) const
+Effect::sibling_union_field_is_read(const Variable *v) const
 {   
-	// check other fields of union/struct
-	if (v->isFieldVarOf_) {
-		for (size_t j=0; j<v->isFieldVarOf_->field_vars.size(); j++) {
-			Variable* field_var = v->isFieldVarOf_->field_vars[j];
-			if (field_var == v) continue;
-			if (is_read(field_var) || field_is_read(field_var)) {
-				return true; 
+	while (v->isFieldVarOf_) {
+		// check other fields of the union
+		if (v->isFieldVarOf_->type->eType == eUnion) {
+			for (size_t j=0; j<v->isFieldVarOf_->field_vars.size(); j++) {
+				Variable* field_var = v->isFieldVarOf_->field_vars[j];
+				if (field_var == v) continue;
+				if (is_read(field_var) || field_is_read(field_var)) {
+					return true; 
+				}
 			}
 		}
+		v = v->isFieldVarOf_;
 	}
 	return false;
 }
 
 bool
-Effect::sibling_field_is_written(const Variable *v) const
+Effect::sibling_union_field_is_written(const Variable *v) const
 {   
-	// check other fields of union/struct
-	if (v->isFieldVarOf_) {
-		for (size_t j=0; j<v->isFieldVarOf_->field_vars.size(); j++) {
-			Variable* field_var = v->isFieldVarOf_->field_vars[j];
-			if (field_var == v) continue;
-			if (is_written(field_var) || field_is_written(field_var)) {
-				return true; 
+	while (v->isFieldVarOf_) {
+		// check other fields of the union
+		if (v->isFieldVarOf_->type->eType == eUnion) {
+			for (size_t j=0; j<v->isFieldVarOf_->field_vars.size(); j++) {
+				Variable* field_var = v->isFieldVarOf_->field_vars[j];
+				if (field_var == v) continue;
+				if (is_written(field_var) || field_is_written(field_var)) {
+					return true; 
+				}
 			}
 		}
+		v = v->isFieldVarOf_;
 	}
 	return false;
 }
@@ -472,13 +478,13 @@ Effect::sibling_field_is_written(const Variable *v) const
 bool 
 Effect::is_read_partially(const Variable* v) const
 {
-	return is_read(v) || field_is_read(v) || (v->is_union_field() && sibling_field_is_read(v));
+	return is_read(v) || field_is_read(v) || sibling_union_field_is_read(v);
 }
 
 bool 
 Effect::is_written_partially(const Variable* v) const
 {
-	return is_written(v) || field_is_written(v) || (v->is_union_field() && sibling_field_is_written(v));
+	return is_written(v) || field_is_written(v) || sibling_union_field_is_written(v);
 }
 
 /*
diff --git a/src/Effect.h b/src/Effect.h
index c771a071f..f459188eb 100644
--- a/src/Effect.h
+++ b/src/Effect.h
@@ -65,8 +65,8 @@ class Effect
 	bool is_written(std::string vname) const;
 	bool field_is_read(const Variable *v) const;
 	bool field_is_written(const Variable *v) const;
-	bool sibling_field_is_read(const Variable *v) const;
-	bool sibling_field_is_written(const Variable *v) const;
+	bool sibling_union_field_is_read(const Variable *v) const;
+	bool sibling_union_field_is_written(const Variable *v) const;
 	bool is_read_partially(const Variable* v) const;  
 	bool is_written_partially(const Variable* v) const;
 	bool union_field_is_read(void) const;