From 3bd62f77a0e85cfb40ca047a8151597e4308c66e Mon Sep 17 00:00:00 2001
From: Xiaozhu Meng <xmeng@cs.wisc.edu>
Date: Wed, 17 May 2017 09:32:16 -0500
Subject: [PATCH] Fix indirect jumps in variable argument functions, where
 there is no memory read

---
 parseAPI/src/IndirectASTVisitor.C  | 10 ++++++++++
 parseAPI/src/IndirectAnalyzer.C    |  1 +
 parseAPI/src/JumpTableFormatPred.C |  2 ++
 parseAPI/src/JumpTableFormatPred.h | 22 ++--------------------
 4 files changed, 15 insertions(+), 20 deletions(-)

diff --git a/parseAPI/src/IndirectASTVisitor.C b/parseAPI/src/IndirectASTVisitor.C
index fcabb7ce6c..b46c430c2d 100644
--- a/parseAPI/src/IndirectASTVisitor.C
+++ b/parseAPI/src/IndirectASTVisitor.C
@@ -312,6 +312,16 @@ bool JumpTableFormatVisitor::PotentialIndexing(AST::Ptr ast) {
     if (ast->getID() == AST::V_RoseAST) {
         RoseAST::Ptr r = boost::static_pointer_cast<RoseAST>(ast);
 	if (r->val().op == ROSEOperation::uMultOp || r->val().op == ROSEOperation::sMultOp) return true;
+	if (r->val().op == ROSEOperation::addOp) {
+	    // The index can be subtracted 
+	    if (r->child(0)->getID() == AST::V_RoseAST && r->child(1)->getID() == AST::V_ConstantAST) {
+	        RoseAST::Ptr lc = boost::static_pointer_cast<RoseAST>(r->child(0));
+		ConstantAST::Ptr rc = boost::static_pointer_cast<ConstantAST>(r->child(1));
+		if (lc->val().op == ROSEOperation::invertOp && rc->val().val == 1) {
+		    return PotentialIndexing(lc->child(0));
+		}
+	    }
+	}
     }
     return false;
 }
diff --git a/parseAPI/src/IndirectAnalyzer.C b/parseAPI/src/IndirectAnalyzer.C
index 83a6d9cc42..2799005516 100644
--- a/parseAPI/src/IndirectAnalyzer.C
+++ b/parseAPI/src/IndirectAnalyzer.C
@@ -206,6 +206,7 @@ void IndirectControlFlowAnalyzer::ReadTable(AST::Ptr jumpTargetExpr,
 }					    
 
 int IndirectControlFlowAnalyzer::GetMemoryReadSize(Assignment::Ptr memLoc) {
+    if (!memLoc) return 0;
     Instruction::Ptr i = memLoc->insn();
     std::vector<Operand> ops;
     i->getOperands(ops);
diff --git a/parseAPI/src/JumpTableFormatPred.C b/parseAPI/src/JumpTableFormatPred.C
index 33e610bf86..3d7b4b9a53 100644
--- a/parseAPI/src/JumpTableFormatPred.C
+++ b/parseAPI/src/JumpTableFormatPred.C
@@ -154,6 +154,7 @@ bool JumpTableFormatPred::modifyCurrentFrame(Slicer::SliceFrame &frame, Graph::P
 	// The last expression should be the jump target
 	jumpTarget = exp;
     }
+    parsing_printf("Check expression %s\n", jumpTarget->format().c_str());
     JumpTableFormatVisitor jtfv(block);
     jumpTarget->accept(&jtfv);
     if (jtfv.findIncorrectFormat) {
@@ -178,6 +179,7 @@ bool JumpTableFormatPred::modifyCurrentFrame(Slicer::SliceFrame &frame, Graph::P
 	findIndex = true;
     }
     if (jtfv.findIndex && jtfv.findTableBase) { 
+        parsing_printf("\tRecord jump target expr\n");
         jumpTargetExpr = jumpTarget;
         return false;
     }
diff --git a/parseAPI/src/JumpTableFormatPred.h b/parseAPI/src/JumpTableFormatPred.h
index 17f7bf2a41..13650430e6 100644
--- a/parseAPI/src/JumpTableFormatPred.h
+++ b/parseAPI/src/JumpTableFormatPred.h
@@ -18,18 +18,6 @@ class JumpTableFormatPred : public Slicer::Predicates {
     ThunkData &thunks;
     SymbolicExpression &se;
 
-    Address targetBase;    
-    // If tableReadSize == 0, this does not represent a memory access
-    // Otherwise, tableReadSize reprenents the number bytes of the access
-    int tableReadSize;
-    int tableStride;
-
-    // On ARM, the table content is often multiplied by 4 before adding with targetBase
-    int tcMultiply;
-    bool isInverted;
-    bool isSubReadContent;
-    bool isZeroExtend;
-
     bool jumpTableFormat;
     bool unknownInstruction;
     bool findIndex;
@@ -48,13 +36,7 @@ class JumpTableFormatPred : public Slicer::Predicates {
 			ThunkData &t,
 			SymbolicExpression &sym):
             func(f), block(b), rf(r), thunks(t), se(sym) {
-	        targetBase = 0;
-		tableReadSize = 0;
-		tcMultiply = 1;
-		isInverted = false;
-		isSubReadContent = false;
-		isZeroExtend = false;
-		jumpTableFormat = true;
+	        jumpTableFormat = true;
 		unknownInstruction = false;
 		findIndex = false;
 		firstMemoryRead = true;
@@ -62,7 +44,7 @@ class JumpTableFormatPred : public Slicer::Predicates {
 
     virtual bool modifyCurrentFrame(Slicer::SliceFrame &frame, Graph::Ptr g);
     std::string format();
-    bool isJumpTableFormat() { return jumpTableFormat && findIndex; }
+    bool isJumpTableFormat() { return jumpTableFormat && findIndex && jumpTargetExpr;}
     bool findSpillRead(Graph::Ptr g, SliceNode::Ptr &);
     void adjustActiveMap(Slicer::SliceFrame &frame, SliceNode::Ptr);
 };