Modified protobuf and converter to add new signature, remove conditionals.

[emmettneyman]

Summary

Cahnged the function signature and removed conditionals from loop body.

[morehouse]

tools/clang-fuzzer/cxx_loop_proto.proto

67

Do you really want to get rid of if-else?

tools/clang-fuzzer/proto-to-cxx/loop_proto_to_cxx.cpp

123

What's the purpose of this include?

[emmettneyman]

@kcc suggested removing conditionals for now and adding them back later. include statement was for testing; I'll remove it and resubmit.

[emmettneyman]

• removed include statement meant for testing

tools/clang-fuzzer/cxx_loop_proto.proto

 //===-- cxx_loop_proto.proto - Protobuf description of C++ with for loops -===//
 //
 //                     The LLVM Compiler Infrastructure
 //
 // This file is distributed under the University of Illinois Open Source
 // License. See LICENSE.TXT for details.
 //
 //===----------------------------------------------------------------------===//
 ///
 /// \file
 ///  This file describes a subset of C++ as a protobuf. It is used to
 ///  more easily find interesting inputs for fuzzing Clang. This subset
 ///  differs from the one defined in cxx_proto.proto by eliminating while
-///  loops and Lvalues. The goal is that the C++ code generated will be
+///  loops and conditionals. The goal is that the C++ code generated will be
 ///  more likely to stress the LLVM loop vectorizer.
 ///
 //===----------------------------------------------------------------------===//
 
 syntax = "proto2";
 
 message Const {
   required int32 val = 1;
 }
 
+message VarRef {
+  // Add an enum for each array in function signature
+  enum Arr {
+    ARR_A = 0;
+    ARR_B = 1;
+    ARR_C = 2;
+  };
+  required Arr arr = 1;
+}
+
 message BinaryOp {
   enum Op {
     PLUS = 0;
     MINUS = 1;
     MUL = 2;
     DIV = 3;
     MOD = 4;
     XOR = 5;
message BinaryOp {
   required Rvalue left = 2;
   required Rvalue right = 3;
 }
 
 message Rvalue {
   oneof rvalue_oneof {
     Const cons = 1;
     BinaryOp binop = 2;
+    VarRef varref = 3;
   }
 }
 
 message AssignmentStatement {
+  required VarRef varref = 1;
   required Rvalue rvalue = 2;
 }
 
 message IfElse {
   required Rvalue cond = 1;
   required StatementSeq if_body = 2;
   required StatementSeq else_body = 3;
 }
 
 message Statement {
-  oneof stmt_oneof {
-    AssignmentStatement assignment = 1;
-    IfElse              ifelse     = 2;
-  }
+  required AssignmentStatement assignment = 1;
 }
 
 message StatementSeq {
   repeated Statement statements = 1;
 }
 
 message LoopFunction {
   required StatementSeq statements = 1;
 }
 
 package clang_fuzzer;

tools/clang-fuzzer/proto-to-cxx/loop_proto_to_cxx.cpp

 // Forward decls.
 std::ostream &operator<<(std::ostream &os, const BinaryOp &x);
 std::ostream &operator<<(std::ostream &os, const StatementSeq &x);
 
 // Proto to C++.
 std::ostream &operator<<(std::ostream &os, const Const &x) {
   return os << "(" << x.val() << ")";
 }
+std::ostream &operator<<(std::ostream &os, const VarRef &x) {
+  switch (x.arr()) {
+    case VarRef::ARR_A:
+      return os << "a[i]";
+    case VarRef::ARR_B:
+      return os << "b[i]";
+    case VarRef::ARR_C:
+      return os << "c[i]";
+  }
+}
 std::ostream &operator<<(std::ostream &os, const Rvalue &x) {
   if (x.has_cons())
     return os << x.cons();
   if (x.has_binop())
     return os << x.binop();
+  if (x.has_varref())
+    return os << x.varref();
   return os << "1";
 }
 std::ostream &operator<<(std::ostream &os, const BinaryOp &x) {
   os << "(" << x.left();
   switch (x.op()) {
   case BinaryOp::PLUS:
     os << "+";
     break;
case BinaryOp::LT:
     break;
   case BinaryOp::GT:
     os << ">";
     break;
   }
   return os << x.right() << ")";
 }
 std::ostream &operator<<(std::ostream &os, const AssignmentStatement &x) {
-  return os << "a[i]=" << x.rvalue();
+  return os << x.varref() << "=" << x.rvalue() << ";\n";
 }
 std::ostream &operator<<(std::ostream &os, const IfElse &x) {
   return os << "if (" << x.cond() << "){\n"
             << x.if_body() << "} else { \n"
             << x.else_body() << "}\n";
 }
 std::ostream &operator<<(std::ostream &os, const Statement &x) {
-  if (x.has_assignment())
-    return os << x.assignment() << ";\n";
-  if (x.has_ifelse())
-    return os << x.ifelse();
-  return os << "(void)0;\n";
+  return os << x.assignment();
 }
 std::ostream &operator<<(std::ostream &os, const StatementSeq &x) {
   for (auto &st : x.statements())
     os << st;
   return os;
 }
 std::ostream &operator<<(std::ostream &os, const LoopFunction &x) {
-  return os << "void foo(int *a, size_t s) {\n"
+  return os << "void foo(int *a, int *b, int *__restrict__ c, size_t s) {\n"
             << "for (int i=0; i<s; i++){\n"
             << x.statements() << "}\n}\n";
 }
 
 // ---------------------------------
 
 std::string LoopFunctionToString(const LoopFunction &input) {
   std::ostringstream os;