private ExpressionSyntax GenIncDec(FuzzType type, bool isIncrement)
{
SyntaxKind[] acceptedTypes =
{
SyntaxKind.ULongKeyword,
SyntaxKind.LongKeyword,
SyntaxKind.UIntKeyword,
SyntaxKind.IntKeyword,
SyntaxKind.UShortKeyword,
SyntaxKind.ShortKeyword,
SyntaxKind.ByteKeyword,
SyntaxKind.SByteKeyword,
};
if (!(type is PrimitiveType pt) || !acceptedTypes.Contains(pt.Keyword))
{
return(null);
}
LValueInfo subject = GenExistingLValue(type, int.MinValue);
if (subject == null)
{
return(null);
}
ExpressionSyntax gen = PostfixUnaryExpression(
isIncrement ? SyntaxKind.PostIncrementExpression : SyntaxKind.PostDecrementExpression,
subject.Expression);
return(gen);
}
/// <summary>Returns an lvalue.</summary>
private LValueInfo GenLValue(FuzzType type, int minRefEscapeScope)
{
Debug.Assert(type != null);
LValueInfo lv = GenExistingLValue(type, minRefEscapeScope);
if (lv == null)
{
StaticField newStatic = Statics.GenerateNewField(type);
lv = new LValueInfo(IdentifierName(newStatic.Var.Name), type, int.MaxValue);
}
return(lv);
}
private static void AppendVariablePaths(List <LValueInfo> paths, VariableIdentifier var)
{
ExpressionSyntax varAccess = IdentifierName(var.Name);
AddPathsRecursive(varAccess, var.Type, var.RefEscapeScope);
void AddPathsRecursive(ExpressionSyntax curAccess, FuzzType curType, int curRefEscapeScope)
{
LValueInfo info = new LValueInfo(curAccess, curType, curRefEscapeScope);
paths.Add(info);
if (curType is RefType rt)
{
curType = rt.InnerType;
}
switch (curType)
{
case ArrayType arr:
AddPathsRecursive(
ElementAccessExpression(
curAccess,
BracketedArgumentList(
SeparatedList(
Enumerable.Repeat(
Argument(LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(0))),
arr.Rank)))),
arr.ElementType,
curRefEscapeScope: int.MaxValue);
break;
case AggregateType agg:
foreach (AggregateField field in agg.Fields)
{
AddPathsRecursive(
MemberAccessExpression(
SyntaxKind.SimpleMemberAccessExpression,
curAccess,
IdentifierName(field.Name)),
field.Type,
curRefEscapeScope: agg.IsClass?int.MaxValue: curRefEscapeScope);
}
break;
}
}
}
private ArgumentSyntax[] GenArgs(FuncGenerator funcToCall, int minRefEscapeScope, out int argsMinRefEscapeScope)
{
ArgumentSyntax[] args = new ArgumentSyntax[funcToCall.Parameters.Length];
argsMinRefEscapeScope = int.MaxValue;
for (int i = 0; i < args.Length; i++)
{
FuzzType paramType = funcToCall.Parameters[i].Type;
if (paramType is RefType rt)
{
LValueInfo lv = GenLValue(rt.InnerType, minRefEscapeScope);
argsMinRefEscapeScope = Math.Min(argsMinRefEscapeScope, lv.RefEscapeScope);
args[i] = Argument(lv.Expression).WithRefKindKeyword(Token(SyntaxKind.RefKeyword));
}
else
{
args[i] = Argument(GenExpression(paramType));
}
}
return(args);
}
private StatementSyntax GenAssignmentStatement()
{
LValueInfo lvalue = null;
if (!Random.FlipCoin(Options.AssignToNewVarProb))
{
lvalue = GenExistingLValue(null, int.MinValue);
}
if (lvalue == null)
{
FuzzType newType = Types.PickType(Options.LocalIsByRefProb);
// Determine if we should create a new local. We do this with a certain probabilty,
// or always if the new type is a by-ref type (we cannot have static by-refs).
if (newType is RefType || Random.FlipCoin(Options.NewVarIsLocalProb))
{
VariableIdentifier variable;
string varName = $"var{_varCounter++}";
ExpressionSyntax rhs;
if (newType is RefType newRt)
{
LValueInfo rhsLV = GenLValue(newRt.InnerType, int.MinValue);
variable = new VariableIdentifier(newType, varName, rhsLV.RefEscapeScope);
rhs = RefExpression(rhsLV.Expression);
}
else
{
rhs = GenExpression(newType);
variable = new VariableIdentifier(newType, varName, -(_scope.Count - 1));
}
LocalDeclarationStatementSyntax decl =
LocalDeclarationStatement(
VariableDeclaration(
variable.Type.GenReferenceTo(),
SingletonSeparatedList(
VariableDeclarator(variable.Name)
.WithInitializer(
EqualsValueClause(rhs)))));
_scope.Last().Variables.Add(variable);
return(decl);
}
StaticField newStatic = Statics.GenerateNewField(newType);
lvalue = new LValueInfo(IdentifierName(newStatic.Var.Name), newType, int.MaxValue);
}
// Determine if we should generate a ref-reassignment. In that case we cannot do anything
// clever, like generate compound assignments.
FuzzType rhsType = lvalue.Type;
if (lvalue.Type is RefType rt)
{
if (Random.FlipCoin(Options.AssignGenRefReassignProb))
{
RefExpressionSyntax refRhs = RefExpression(GenLValue(rt.InnerType, lvalue.RefEscapeScope).Expression);
return
(ExpressionStatement(
AssignmentExpression(
SyntaxKind.SimpleAssignmentExpression,
lvalue.Expression,
refRhs)));
}
// We have a ref-type, but are not generating a ref-reassign, so lift the type and make a normal assignment.
rhsType = rt.InnerType;
}
SyntaxKind assignmentKind = SyntaxKind.SimpleAssignmentExpression;
// Determine if we should generate compound assignment.
if (rhsType.AllowedAdditionalAssignmentKinds.Length > 0 && Random.FlipCoin(Options.CompoundAssignmentProb))
{
assignmentKind = Random.NextElement(rhsType.AllowedAdditionalAssignmentKinds);
}
// Early our for simple cases.
if (assignmentKind == SyntaxKind.PreIncrementExpression ||
assignmentKind == SyntaxKind.PreDecrementExpression)
{
return(ExpressionStatement(PrefixUnaryExpression(assignmentKind, lvalue.Expression)));
}
if (assignmentKind == SyntaxKind.PostIncrementExpression ||
assignmentKind == SyntaxKind.PostDecrementExpression)
{
return(ExpressionStatement(PostfixUnaryExpression(assignmentKind, lvalue.Expression)));
}
// Right operand of shifts are always ints.
if (assignmentKind == SyntaxKind.LeftShiftAssignmentExpression ||
assignmentKind == SyntaxKind.RightShiftAssignmentExpression)
{
rhsType = Types.GetPrimitiveType(SyntaxKind.IntKeyword);
}
ExpressionSyntax right = GenExpression(rhsType);
// For modulo and division we don't want to throw divide-by-zero exceptions,
// so always or right-hand-side with 1.
if (assignmentKind == SyntaxKind.ModuloAssignmentExpression ||
assignmentKind == SyntaxKind.DivideAssignmentExpression)
{
right =
CastExpression(
rhsType.GenReferenceTo(),
ParenthesizedExpression(
BinaryExpression(
SyntaxKind.BitwiseOrExpression,
ParenthesizeIfNecessary(right),
LiteralExpression(SyntaxKind.NumericLiteralExpression, Literal(1)))));
}
return(ExpressionStatement(AssignmentExpression(assignmentKind, lvalue.Expression, right)));
}