//
// Author:
// Miguel de Icaza (miguel@ximian.com)
+// Martin Baulig (martin@gnome.org)
//
// (C) 2001, 2002 Ximian, Inc.
//
using System;
+using System.Text;
using System.Reflection;
using System.Reflection.Emit;
using System.Diagnostics;
/// <summary>
/// Return value indicates whether all code paths emitted return.
/// </summary>
- public abstract bool Emit (EmitContext ec);
+ protected abstract bool DoEmit (EmitContext ec);
+
+ /// <summary>
+ /// Return value indicates whether all code paths emitted return.
+ /// </summary>
+ public virtual bool Emit (EmitContext ec)
+ {
+ ec.Mark (loc);
+ Report.Debug (8, "MARK", this, loc);
+ return DoEmit (ec);
+ }
public static Expression ResolveBoolean (EmitContext ec, Expression e, Location loc)
{
31, loc, "Can not convert the expression to a boolean");
}
- if (CodeGen.SymbolWriter != null)
- ec.Mark (loc);
+ ec.Mark (loc);
return e;
}
/// <remarks>
- /// Emits a bool expression.
+ /// Encapsulates the emission of a boolean test and jumping to a
+ /// destination.
+ ///
+ /// This will emit the bool expression in `bool_expr' and if
+ /// `target_is_for_true' is true, then the code will generate a
+ /// brtrue to the target. Otherwise a brfalse.
/// </remarks>
public static void EmitBoolExpression (EmitContext ec, Expression bool_expr,
- Label target, bool isTrue)
+ Label target, bool target_is_for_true)
{
ILGenerator ig = ec.ig;
u.EmitLogicalNot (ec);
}
- }
+ } else if (bool_expr is Binary){
+ Binary b = (Binary) bool_expr;
+
+ if (b.EmitBranchable (ec, target, target_is_for_true))
+ return;
+ }
if (!invert)
bool_expr.Emit (ec);
- if (isTrue){
+ if (target_is_for_true){
if (invert)
ig.Emit (OpCodes.Brfalse, target);
else
return true;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
return false;
}
public override bool Resolve (EmitContext ec)
{
+ Report.Debug (1, "START IF BLOCK", loc);
+
expr = ResolveBoolean (ec, expr, loc);
if (expr == null){
return false;
}
- if (TrueStatement.Resolve (ec)){
- if (FalseStatement != null){
- if (FalseStatement.Resolve (ec))
- return true;
-
- return false;
- }
- return true;
+ ec.StartFlowBranching (FlowBranchingType.BLOCK, loc);
+
+ if (!TrueStatement.Resolve (ec)) {
+ ec.KillFlowBranching ();
+ return false;
}
- return false;
+
+ ec.CurrentBranching.CreateSibling ();
+
+ if ((FalseStatement != null) && !FalseStatement.Resolve (ec)) {
+ ec.KillFlowBranching ();
+ return false;
+ }
+
+ ec.EndFlowBranching ();
+
+ Report.Debug (1, "END IF BLOCK", loc);
+
+ return true;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
ILGenerator ig = ec.ig;
Label false_target = ig.DefineLabel ();
}
EmitBoolExpression (ec, expr, false_target, false);
-
+
is_true_ret = TrueStatement.Emit (ec);
is_false_ret = is_true_ret;
ig.Emit (OpCodes.Br, end);
branch_emitted = true;
}
-
+
ig.MarkLabel (false_target);
is_false_ret = FalseStatement.Emit (ec);
public class Do : Statement {
public Expression expr;
public readonly Statement EmbeddedStatement;
+ bool infinite, may_return;
public Do (Statement statement, Expression boolExpr, Location l)
{
public override bool Resolve (EmitContext ec)
{
+ bool ok = true;
+
+ ec.StartFlowBranching (FlowBranchingType.LOOP_BLOCK, loc);
+
+ if (!EmbeddedStatement.Resolve (ec))
+ ok = false;
+
expr = ResolveBoolean (ec, expr, loc);
if (expr == null)
- return false;
-
- return EmbeddedStatement.Resolve (ec);
+ ok = false;
+ else if (expr is BoolConstant){
+ bool res = ((BoolConstant) expr).Value;
+
+ if (res)
+ infinite = true;
+ }
+
+ ec.CurrentBranching.Infinite = infinite;
+ FlowReturns returns = ec.EndFlowBranching ();
+ may_return = returns != FlowReturns.NEVER;
+
+ return ok;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
ILGenerator ig = ec.ig;
Label loop = ig.DefineLabel ();
Label old_begin = ec.LoopBegin;
Label old_end = ec.LoopEnd;
bool old_inloop = ec.InLoop;
- bool old_breaks = ec.Breaks;
+ int old_loop_begin_try_catch_level = ec.LoopBeginTryCatchLevel;
ec.LoopBegin = ig.DefineLabel ();
ec.LoopEnd = ig.DefineLabel ();
ec.InLoop = true;
+ ec.LoopBeginTryCatchLevel = ec.TryCatchLevel;
ig.MarkLabel (loop);
- ec.Breaks = false;
EmbeddedStatement.Emit (ec);
- bool breaks = ec.Breaks;
ig.MarkLabel (ec.LoopBegin);
//
ig.MarkLabel (ec.LoopEnd);
+ ec.LoopBeginTryCatchLevel = old_loop_begin_try_catch_level;
ec.LoopBegin = old_begin;
ec.LoopEnd = old_end;
ec.InLoop = old_inloop;
- ec.Breaks = old_breaks;
-
- //
- // Inform whether we are infinite or not
- //
- if (expr is BoolConstant){
- BoolConstant bc = (BoolConstant) expr;
- if (bc.Value == true)
- return breaks == false;
- }
-
- return false;
+ if (infinite)
+ return may_return == false;
+ else
+ return false;
}
}
public class While : Statement {
public Expression expr;
public readonly Statement Statement;
+ bool may_return, empty, infinite;
public While (Expression boolExpr, Statement statement, Location l)
{
public override bool Resolve (EmitContext ec)
{
+ bool ok = true;
+
expr = ResolveBoolean (ec, expr, loc);
if (expr == null)
return false;
-
- return Statement.Resolve (ec);
+
+ ec.StartFlowBranching (FlowBranchingType.LOOP_BLOCK, loc);
+
+ //
+ // Inform whether we are infinite or not
+ //
+ if (expr is BoolConstant){
+ BoolConstant bc = (BoolConstant) expr;
+
+ if (bc.Value == false){
+ Warning_DeadCodeFound (Statement.loc);
+ empty = true;
+ } else
+ infinite = true;
+ } else {
+ //
+ // We are not infinite, so the loop may or may not be executed.
+ //
+ ec.CurrentBranching.CreateSibling ();
+ }
+
+ if (!Statement.Resolve (ec))
+ ok = false;
+
+ if (empty)
+ ec.KillFlowBranching ();
+ else {
+ ec.CurrentBranching.Infinite = infinite;
+ FlowReturns returns = ec.EndFlowBranching ();
+ may_return = returns != FlowReturns.NEVER;
+ }
+
+ return ok;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
+ if (empty)
+ return false;
+
ILGenerator ig = ec.ig;
Label old_begin = ec.LoopBegin;
Label old_end = ec.LoopEnd;
bool old_inloop = ec.InLoop;
- bool old_breaks = ec.Breaks;
- Label while_loop = ig.DefineLabel ();
+ int old_loop_begin_try_catch_level = ec.LoopBeginTryCatchLevel;
bool ret;
ec.LoopBegin = ig.DefineLabel ();
ec.LoopEnd = ig.DefineLabel ();
ec.InLoop = true;
-
- ig.Emit (OpCodes.Br, ec.LoopBegin);
- ig.MarkLabel (while_loop);
+ ec.LoopBeginTryCatchLevel = ec.TryCatchLevel;
//
// Inform whether we are infinite or not
BoolConstant bc = (BoolConstant) expr;
ig.MarkLabel (ec.LoopBegin);
- if (bc.Value == false){
- Warning_DeadCodeFound (Statement.loc);
- ret = false;
- } else {
- bool breaks;
-
- ec.Breaks = false;
- Statement.Emit (ec);
- breaks = ec.Breaks;
- ig.Emit (OpCodes.Br, ec.LoopBegin);
+ Statement.Emit (ec);
+ ig.Emit (OpCodes.Br, ec.LoopBegin);
- //
- // Inform that we are infinite (ie, `we return'), only
- // if we do not `break' inside the code.
- //
- ret = breaks == false;
- }
+ //
+ // Inform that we are infinite (ie, `we return'), only
+ // if we do not `break' inside the code.
+ //
+ ret = may_return == false;
ig.MarkLabel (ec.LoopEnd);
} else {
+ Label while_loop = ig.DefineLabel ();
+
+ ig.Emit (OpCodes.Br, ec.LoopBegin);
+ ig.MarkLabel (while_loop);
+
Statement.Emit (ec);
ig.MarkLabel (ec.LoopBegin);
ec.LoopBegin = old_begin;
ec.LoopEnd = old_end;
ec.InLoop = old_inloop;
- ec.Breaks = old_breaks;
+ ec.LoopBeginTryCatchLevel = old_loop_begin_try_catch_level;
return ret;
}
readonly Statement InitStatement;
readonly Statement Increment;
readonly Statement Statement;
+ bool may_return, infinite, empty;
public For (Statement initStatement,
Expression test,
{
bool ok = true;
+ if (InitStatement != null){
+ if (!InitStatement.Resolve (ec))
+ ok = false;
+ }
+
if (Test != null){
Test = ResolveBoolean (ec, Test, loc);
if (Test == null)
ok = false;
- }
+ else if (Test is BoolConstant){
+ BoolConstant bc = (BoolConstant) Test;
- if (InitStatement != null){
- if (!InitStatement.Resolve (ec))
- ok = false;
- }
+ if (bc.Value == false){
+ Warning_DeadCodeFound (Statement.loc);
+ empty = true;
+ } else
+ infinite = true;
+ }
+ } else
+ infinite = true;
if (Increment != null){
if (!Increment.Resolve (ec))
ok = false;
}
-
- return Statement.Resolve (ec) && ok;
+
+ ec.StartFlowBranching (FlowBranchingType.LOOP_BLOCK, loc);
+ if (!infinite)
+ ec.CurrentBranching.CreateSibling ();
+
+ if (!Statement.Resolve (ec))
+ ok = false;
+
+ if (empty)
+ ec.KillFlowBranching ();
+ else {
+ ec.CurrentBranching.Infinite = infinite;
+ FlowReturns returns = ec.EndFlowBranching ();
+ may_return = returns != FlowReturns.NEVER;
+ }
+
+ return ok;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
+ if (empty)
+ return false;
+
ILGenerator ig = ec.ig;
Label old_begin = ec.LoopBegin;
Label old_end = ec.LoopEnd;
bool old_inloop = ec.InLoop;
- bool old_breaks = ec.Breaks;
+ int old_loop_begin_try_catch_level = ec.LoopBeginTryCatchLevel;
Label loop = ig.DefineLabel ();
-
+ Label test = ig.DefineLabel ();
+
if (InitStatement != null)
if (! (InitStatement is EmptyStatement))
InitStatement.Emit (ec);
ec.LoopBegin = ig.DefineLabel ();
ec.LoopEnd = ig.DefineLabel ();
ec.InLoop = true;
+ ec.LoopBeginTryCatchLevel = ec.TryCatchLevel;
+ ig.Emit (OpCodes.Br, test);
ig.MarkLabel (loop);
+ Statement.Emit (ec);
+
+ ig.MarkLabel (ec.LoopBegin);
+ if (!(Increment is EmptyStatement))
+ Increment.Emit (ec);
+ ig.MarkLabel (test);
//
// If test is null, there is no test, and we are just
// an infinite loop
//
if (Test != null)
- EmitBoolExpression (ec, Test, ec.LoopEnd, false);
-
- ec.Breaks = false;
- Statement.Emit (ec);
- bool breaks = ec.Breaks;
-
- ig.MarkLabel (ec.LoopBegin);
- if (!(Increment is EmptyStatement))
- Increment.Emit (ec);
- ig.Emit (OpCodes.Br, loop);
+ EmitBoolExpression (ec, Test, loop, true);
+ else
+ ig.Emit (OpCodes.Br, loop);
ig.MarkLabel (ec.LoopEnd);
ec.LoopBegin = old_begin;
ec.LoopEnd = old_end;
ec.InLoop = old_inloop;
- ec.Breaks = old_breaks;
+ ec.LoopBeginTryCatchLevel = old_loop_begin_try_catch_level;
//
- // Inform whether we are infinite or not
+ // Inform whether we are infinite or not
//
if (Test != null){
if (Test is BoolConstant){
BoolConstant bc = (BoolConstant) Test;
if (bc.Value)
- return breaks == false;
+ return may_return == false;
}
return false;
} else
- return true;
+ return may_return == false;
}
}
return expr != null;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
ILGenerator ig = ec.ig;
if (Expr == null)
return false;
}
+
+ FlowBranching.UsageVector vector = ec.CurrentBranching.CurrentUsageVector;
+
+ if (ec.CurrentBranching.InTryBlock ())
+ ec.CurrentBranching.AddFinallyVector (vector);
+ else
+ vector.CheckOutParameters (ec.CurrentBranching);
+
+ vector.Returns = FlowReturns.ALWAYS;
+ vector.Breaks = FlowReturns.ALWAYS;
return true;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
if (ec.InFinally){
Report.Error (157,loc,"Control can not leave the body of the finally block");
if (ec.ReturnType == null){
if (Expr != null){
Report.Error (127, loc, "Return with a value not allowed here");
- return false;
+ return true;
}
} else {
if (Expr == null){
Report.Error (126, loc, "An object of type `" +
TypeManager.CSharpName (ec.ReturnType) + "' is " +
"expected for the return statement");
- return false;
+ return true;
}
if (Expr.Type != ec.ReturnType)
ec, Expr, ec.ReturnType, loc);
if (Expr == null)
- return false;
+ return true;
Expr.Emit (ec);
ec.ig.Emit (OpCodes.Stloc, ec.TemporaryReturn ());
}
- if (ec.InTry || ec.InCatch)
+ if (ec.InTry || ec.InCatch) {
+ if (!ec.HasReturnLabel) {
+ ec.ReturnLabel = ec.ig.DefineLabel ();
+ ec.HasReturnLabel = true;
+ }
ec.ig.Emit (OpCodes.Leave, ec.ReturnLabel);
- else
+ } else
ec.ig.Emit (OpCodes.Ret);
return true;
public class Goto : Statement {
string target;
Block block;
+ LabeledStatement label;
public override bool Resolve (EmitContext ec)
{
+ label = block.LookupLabel (target);
+ if (label == null){
+ Report.Error (
+ 159, loc,
+ "No such label `" + target + "' in this scope");
+ return false;
+ }
+
+ // If this is a forward goto.
+ if (!label.IsDefined)
+ label.AddUsageVector (ec.CurrentBranching.CurrentUsageVector);
+
+ ec.CurrentBranching.CurrentUsageVector.Breaks = FlowReturns.ALWAYS;
+
return true;
}
}
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
- LabeledStatement label = block.LookupLabel (target);
-
- if (label == null){
- //
- // Maybe we should catch this before?
- //
- Report.Error (
- 159, loc,
- "No such label `" + target + "' in this scope");
- return false;
- }
Label l = label.LabelTarget (ec);
ec.ig.Emit (OpCodes.Br, l);
}
public class LabeledStatement : Statement {
+ public readonly Location Location;
string label_name;
bool defined;
+ bool referenced;
Label label;
+
+ ArrayList vectors;
- public LabeledStatement (string label_name)
+ public LabeledStatement (string label_name, Location l)
{
this.label_name = label_name;
+ this.Location = l;
}
public Label LabelTarget (EmitContext ec)
return label;
}
- public override bool Emit (EmitContext ec)
+ public bool IsDefined {
+ get {
+ return defined;
+ }
+ }
+
+ public bool HasBeenReferenced {
+ get {
+ return referenced;
+ }
+ }
+
+ public void AddUsageVector (FlowBranching.UsageVector vector)
+ {
+ if (vectors == null)
+ vectors = new ArrayList ();
+
+ vectors.Add (vector.Clone ());
+ }
+
+ public override bool Resolve (EmitContext ec)
+ {
+ if (vectors != null)
+ ec.CurrentBranching.CurrentUsageVector.MergeJumpOrigins (vectors);
+ else {
+ ec.CurrentBranching.CurrentUsageVector.Breaks = FlowReturns.NEVER;
+ ec.CurrentBranching.CurrentUsageVector.Returns = FlowReturns.NEVER;
+ }
+
+ referenced = true;
+
+ return true;
+ }
+
+ protected override bool DoEmit (EmitContext ec)
{
LabelTarget (ec);
ec.ig.MarkLabel (label);
loc = l;
}
- public override bool Emit (EmitContext ec)
+ public override bool Resolve (EmitContext ec)
+ {
+ ec.CurrentBranching.CurrentUsageVector.Breaks = FlowReturns.UNREACHABLE;
+ return true;
+ }
+
+ protected override bool DoEmit (EmitContext ec)
{
if (ec.Switch == null){
Report.Error (153, loc, "goto default is only valid in a switch statement");
/// </summary>
public class GotoCase : Statement {
Expression expr;
+ Label label;
public GotoCase (Expression e, Location l)
{
loc = l;
}
- public override bool Emit (EmitContext ec)
+ public override bool Resolve (EmitContext ec)
{
if (ec.Switch == null){
Report.Error (153, loc, "goto case is only valid in a switch statement");
"No such label 'case " + val + "': for the goto case");
}
- ec.ig.Emit (OpCodes.Br, sl.ILLabelCode);
+ label = sl.ILLabelCode;
+
+ ec.CurrentBranching.CurrentUsageVector.Breaks = FlowReturns.UNREACHABLE;
+ return true;
+ }
+
+ protected override bool DoEmit (EmitContext ec)
+ {
+ ec.ig.Emit (OpCodes.Br, label);
return true;
}
}
expr = expr.Resolve (ec);
if (expr == null)
return false;
+
+ ExprClass eclass = expr.eclass;
+
+ if (!(eclass == ExprClass.Variable || eclass == ExprClass.PropertyAccess ||
+ eclass == ExprClass.Value || eclass == ExprClass.IndexerAccess)) {
+ expr.Error118 ("value, variable, property or indexer access ");
+ return false;
+ }
+
+ Type t = expr.Type;
+
+ if ((t != TypeManager.exception_type) &&
+ !t.IsSubclassOf (TypeManager.exception_type) &&
+ !(expr is NullLiteral)) {
+ Report.Error (155, loc,
+ "The type caught or thrown must be derived " +
+ "from System.Exception");
+ return false;
+ }
}
+
+ ec.CurrentBranching.CurrentUsageVector.Returns = FlowReturns.EXCEPTION;
+ ec.CurrentBranching.CurrentUsageVector.Breaks = FlowReturns.EXCEPTION;
return true;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
if (expr == null){
if (ec.InCatch)
}
return false;
}
-
+
expr.Emit (ec);
ec.ig.Emit (OpCodes.Throw);
loc = l;
}
- public override bool Emit (EmitContext ec)
+ public override bool Resolve (EmitContext ec)
+ {
+ ec.CurrentBranching.MayLeaveLoop = true;
+ ec.CurrentBranching.CurrentUsageVector.Breaks = FlowReturns.ALWAYS;
+ return true;
+ }
+
+ protected override bool DoEmit (EmitContext ec)
{
ILGenerator ig = ec.ig;
return false;
}
- ec.Breaks = true;
- ig.Emit (OpCodes.Br, ec.LoopEnd);
+ if (ec.InTry || ec.InCatch)
+ ig.Emit (OpCodes.Leave, ec.LoopEnd);
+ else
+ ig.Emit (OpCodes.Br, ec.LoopEnd);
return false;
}
loc = l;
}
- public override bool Emit (EmitContext ec)
+ public override bool Resolve (EmitContext ec)
+ {
+ ec.CurrentBranching.CurrentUsageVector.Breaks = FlowReturns.ALWAYS;
+ return true;
+ }
+
+ protected override bool DoEmit (EmitContext ec)
{
Label begin = ec.LoopBegin;
// From:
// try {} catch { while () { continue; }}
//
- ec.ig.Emit (OpCodes.Br, begin);
+ if (ec.TryCatchLevel > ec.LoopBeginTryCatchLevel)
+ ec.ig.Emit (OpCodes.Leave, begin);
+ else if (ec.TryCatchLevel < ec.LoopBeginTryCatchLevel)
+ throw new Exception ("Should never happen");
+ else
+ ec.ig.Emit (OpCodes.Br, begin);
return false;
}
}
-
- public class VariableInfo {
- public readonly string Type;
- public LocalBuilder LocalBuilder;
- public Type VariableType;
- public readonly Location Location;
-
- public bool Used;
- public bool Assigned;
- public bool ReadOnly;
-
- public VariableInfo (string type, Location l)
+
+ // <summary>
+ // This is used in the control flow analysis code to specify whether the
+ // current code block may return to its enclosing block before reaching
+ // its end.
+ // </summary>
+ public enum FlowReturns {
+ // It can never return.
+ NEVER,
+
+ // This means that the block contains a conditional return statement
+ // somewhere.
+ SOMETIMES,
+
+ // The code always returns, ie. there's an unconditional return / break
+ // statement in it.
+ ALWAYS,
+
+ // The code always throws an exception.
+ EXCEPTION,
+
+ // The current code block is unreachable. This happens if it's immediately
+ // following a FlowReturns.ALWAYS block.
+ UNREACHABLE
+ }
+
+ // <summary>
+ // This is a special bit vector which can inherit from another bit vector doing a
+ // copy-on-write strategy. The inherited vector may have a smaller size than the
+ // current one.
+ // </summary>
+ public class MyBitVector {
+ public readonly int Count;
+ public readonly MyBitVector InheritsFrom;
+
+ bool is_dirty;
+ BitArray vector;
+
+ public MyBitVector (int Count)
+ : this (null, Count)
+ { }
+
+ public MyBitVector (MyBitVector InheritsFrom, int Count)
{
- Type = type;
- LocalBuilder = null;
- Location = l;
+ this.InheritsFrom = InheritsFrom;
+ this.Count = Count;
}
- public void MakePinned ()
+ // <summary>
+ // Checks whether this bit vector has been modified. After setting this to true,
+ // we won't use the inherited vector anymore, but our own copy of it.
+ // </summary>
+ public bool IsDirty {
+ get {
+ return is_dirty;
+ }
+
+ set {
+ if (!is_dirty)
+ initialize_vector ();
+ }
+ }
+
+ // <summary>
+ // Get/set bit `index' in the bit vector.
+ // </summary>
+ public bool this [int index]
+ {
+ get {
+ if (index > Count)
+ throw new ArgumentOutOfRangeException ();
+
+ // We're doing a "copy-on-write" strategy here; as long
+ // as nobody writes to the array, we can use our parent's
+ // copy instead of duplicating the vector.
+
+ if (vector != null)
+ return vector [index];
+ else if (InheritsFrom != null) {
+ BitArray inherited = InheritsFrom.Vector;
+
+ if (index < inherited.Count)
+ return inherited [index];
+ else
+ return false;
+ } else
+ return false;
+ }
+
+ set {
+ if (index > Count)
+ throw new ArgumentOutOfRangeException ();
+
+ // Only copy the vector if we're actually modifying it.
+
+ if (this [index] != value) {
+ initialize_vector ();
+
+ vector [index] = value;
+ }
+ }
+ }
+
+ // <summary>
+ // If you explicitly convert the MyBitVector to a BitArray, you will get a deep
+ // copy of the bit vector.
+ // </summary>
+ public static explicit operator BitArray (MyBitVector vector)
+ {
+ vector.initialize_vector ();
+ return vector.Vector;
+ }
+
+ // <summary>
+ // Performs an `or' operation on the bit vector. The `new_vector' may have a
+ // different size than the current one.
+ // </summary>
+ public void Or (MyBitVector new_vector)
+ {
+ BitArray new_array = new_vector.Vector;
+
+ initialize_vector ();
+
+ int upper;
+ if (vector.Count < new_array.Count)
+ upper = vector.Count;
+ else
+ upper = new_array.Count;
+
+ for (int i = 0; i < upper; i++)
+ vector [i] = vector [i] | new_array [i];
+ }
+
+ // <summary>
+ // Perfonrms an `and' operation on the bit vector. The `new_vector' may have
+ // a different size than the current one.
+ // </summary>
+ public void And (MyBitVector new_vector)
+ {
+ BitArray new_array = new_vector.Vector;
+
+ initialize_vector ();
+
+ int lower, upper;
+ if (vector.Count < new_array.Count)
+ lower = upper = vector.Count;
+ else {
+ lower = new_array.Count;
+ upper = vector.Count;
+ }
+
+ for (int i = 0; i < lower; i++)
+ vector [i] = vector [i] & new_array [i];
+
+ for (int i = lower; i < upper; i++)
+ vector [i] = false;
+ }
+
+ // <summary>
+ // This does a deep copy of the bit vector.
+ // </summary>
+ public MyBitVector Clone ()
+ {
+ MyBitVector retval = new MyBitVector (Count);
+
+ retval.Vector = Vector;
+
+ return retval;
+ }
+
+ BitArray Vector {
+ get {
+ if (vector != null)
+ return vector;
+ else if (!is_dirty && (InheritsFrom != null))
+ return InheritsFrom.Vector;
+
+ initialize_vector ();
+
+ return vector;
+ }
+
+ set {
+ initialize_vector ();
+
+ for (int i = 0; i < Math.Min (vector.Count, value.Count); i++)
+ vector [i] = value [i];
+ }
+ }
+
+ void initialize_vector ()
+ {
+ if (vector != null)
+ return;
+
+ vector = new BitArray (Count, false);
+ if (InheritsFrom != null)
+ Vector = InheritsFrom.Vector;
+
+ is_dirty = true;
+ }
+
+ public override string ToString ()
+ {
+ StringBuilder sb = new StringBuilder ("MyBitVector (");
+
+ BitArray vector = Vector;
+ sb.Append (Count);
+ sb.Append (",");
+ if (!IsDirty)
+ sb.Append ("INHERITED - ");
+ for (int i = 0; i < vector.Count; i++) {
+ if (i > 0)
+ sb.Append (",");
+ sb.Append (vector [i]);
+ }
+
+ sb.Append (")");
+ return sb.ToString ();
+ }
+ }
+
+ // <summary>
+ // The type of a FlowBranching.
+ // </summary>
+ public enum FlowBranchingType {
+ // Normal (conditional or toplevel) block.
+ BLOCK,
+
+ // A loop block.
+ LOOP_BLOCK,
+
+ // Try/Catch block.
+ EXCEPTION,
+
+ // Switch block.
+ SWITCH,
+
+ // Switch section.
+ SWITCH_SECTION
+ }
+
+ // <summary>
+ // A new instance of this class is created every time a new block is resolved
+ // and if there's branching in the block's control flow.
+ // </summary>
+ public class FlowBranching {
+ // <summary>
+ // The type of this flow branching.
+ // </summary>
+ public readonly FlowBranchingType Type;
+
+ // <summary>
+ // The block this branching is contained in. This may be null if it's not
+ // a top-level block and it doesn't declare any local variables.
+ // </summary>
+ public readonly Block Block;
+
+ // <summary>
+ // The parent of this branching or null if this is the top-block.
+ // </summary>
+ public readonly FlowBranching Parent;
+
+ // <summary>
+ // Start-Location of this flow branching.
+ // </summary>
+ public readonly Location Location;
+
+ // <summary>
+ // A list of UsageVectors. A new vector is added each time control flow may
+ // take a different path.
+ // </summary>
+ public ArrayList Siblings;
+
+ // <summary>
+ // If this is an infinite loop.
+ // </summary>
+ public bool Infinite;
+
+ // <summary>
+ // If we may leave the current loop.
+ // </summary>
+ public bool MayLeaveLoop;
+
+ //
+ // Private
+ //
+ InternalParameters param_info;
+ int[] param_map;
+ MyStructInfo[] struct_params;
+ int num_params;
+ ArrayList finally_vectors;
+
+ static int next_id = 0;
+ int id;
+
+ // <summary>
+ // Performs an `And' operation on the FlowReturns status
+ // (for instance, a block only returns ALWAYS if all its siblings
+ // always return).
+ // </summary>
+ public static FlowReturns AndFlowReturns (FlowReturns a, FlowReturns b)
+ {
+ if (b == FlowReturns.UNREACHABLE)
+ return a;
+
+ switch (a) {
+ case FlowReturns.NEVER:
+ if (b == FlowReturns.NEVER)
+ return FlowReturns.NEVER;
+ else
+ return FlowReturns.SOMETIMES;
+
+ case FlowReturns.SOMETIMES:
+ return FlowReturns.SOMETIMES;
+
+ case FlowReturns.ALWAYS:
+ if ((b == FlowReturns.ALWAYS) || (b == FlowReturns.EXCEPTION))
+ return FlowReturns.ALWAYS;
+ else
+ return FlowReturns.SOMETIMES;
+
+ case FlowReturns.EXCEPTION:
+ if (b == FlowReturns.EXCEPTION)
+ return FlowReturns.EXCEPTION;
+ else if (b == FlowReturns.ALWAYS)
+ return FlowReturns.ALWAYS;
+ else
+ return FlowReturns.SOMETIMES;
+ }
+
+ return b;
+ }
+
+ // <summary>
+ // The vector contains a BitArray with information about which local variables
+ // and parameters are already initialized at the current code position.
+ // </summary>
+ public class UsageVector {
+ // <summary>
+ // If this is true, then the usage vector has been modified and must be
+ // merged when we're done with this branching.
+ // </summary>
+ public bool IsDirty;
+
+ // <summary>
+ // The number of parameters in this block.
+ // </summary>
+ public readonly int CountParameters;
+
+ // <summary>
+ // The number of locals in this block.
+ // </summary>
+ public readonly int CountLocals;
+
+ // <summary>
+ // If not null, then we inherit our state from this vector and do a
+ // copy-on-write. If null, then we're the first sibling in a top-level
+ // block and inherit from the empty vector.
+ // </summary>
+ public readonly UsageVector InheritsFrom;
+
+ //
+ // Private.
+ //
+ MyBitVector locals, parameters;
+ FlowReturns real_returns, real_breaks;
+ bool is_finally;
+
+ static int next_id = 0;
+ int id;
+
+ //
+ // Normally, you should not use any of these constructors.
+ //
+ public UsageVector (UsageVector parent, int num_params, int num_locals)
+ {
+ this.InheritsFrom = parent;
+ this.CountParameters = num_params;
+ this.CountLocals = num_locals;
+ this.real_returns = FlowReturns.NEVER;
+ this.real_breaks = FlowReturns.NEVER;
+
+ if (parent != null) {
+ locals = new MyBitVector (parent.locals, CountLocals);
+ if (num_params > 0)
+ parameters = new MyBitVector (parent.parameters, num_params);
+ real_returns = parent.Returns;
+ real_breaks = parent.Breaks;
+ } else {
+ locals = new MyBitVector (null, CountLocals);
+ if (num_params > 0)
+ parameters = new MyBitVector (null, num_params);
+ }
+
+ id = ++next_id;
+ }
+
+ public UsageVector (UsageVector parent)
+ : this (parent, parent.CountParameters, parent.CountLocals)
+ { }
+
+ // <summary>
+ // This does a deep copy of the usage vector.
+ // </summary>
+ public UsageVector Clone ()
+ {
+ UsageVector retval = new UsageVector (null, CountParameters, CountLocals);
+
+ retval.locals = locals.Clone ();
+ if (parameters != null)
+ retval.parameters = parameters.Clone ();
+ retval.real_returns = real_returns;
+ retval.real_breaks = real_breaks;
+
+ return retval;
+ }
+
+ //
+ // State of parameter `number'.
+ //
+ public bool this [int number]
+ {
+ get {
+ if (number == -1)
+ return true;
+ else if (number == 0)
+ throw new ArgumentException ();
+
+ return parameters [number - 1];
+ }
+
+ set {
+ if (number == -1)
+ return;
+ else if (number == 0)
+ throw new ArgumentException ();
+
+ parameters [number - 1] = value;
+ }
+ }
+
+ //
+ // State of the local variable `vi'.
+ // If the local variable is a struct, use a non-zero `field_idx'
+ // to check an individual field in it.
+ //
+ public bool this [VariableInfo vi, int field_idx]
+ {
+ get {
+ if (vi.Number == -1)
+ return true;
+ else if (vi.Number == 0)
+ throw new ArgumentException ();
+
+ return locals [vi.Number + field_idx - 1];
+ }
+
+ set {
+ if (vi.Number == -1)
+ return;
+ else if (vi.Number == 0)
+ throw new ArgumentException ();
+
+ locals [vi.Number + field_idx - 1] = value;
+ }
+ }
+
+ // <summary>
+ // Specifies when the current block returns.
+ // If this is FlowReturns.UNREACHABLE, then control can never reach the
+ // end of the method (so that we don't need to emit a return statement).
+ // The same applies for FlowReturns.EXCEPTION, but in this case the return
+ // value will never be used.
+ // </summary>
+ public FlowReturns Returns {
+ get {
+ return real_returns;
+ }
+
+ set {
+ real_returns = value;
+ }
+ }
+
+ // <summary>
+ // Specifies whether control may return to our containing block
+ // before reaching the end of this block. This happens if there
+ // is a break/continue/goto/return in it.
+ // This can also be used to find out whether the statement immediately
+ // following the current block may be reached or not.
+ // </summary>
+ public FlowReturns Breaks {
+ get {
+ return real_breaks;
+ }
+
+ set {
+ real_breaks = value;
+ }
+ }
+
+ public bool AlwaysBreaks {
+ get {
+ return (Breaks == FlowReturns.ALWAYS) ||
+ (Breaks == FlowReturns.EXCEPTION) ||
+ (Breaks == FlowReturns.UNREACHABLE);
+ }
+ }
+
+ public bool MayBreak {
+ get {
+ return Breaks != FlowReturns.NEVER;
+ }
+ }
+
+ public bool AlwaysReturns {
+ get {
+ return (Returns == FlowReturns.ALWAYS) ||
+ (Returns == FlowReturns.EXCEPTION);
+ }
+ }
+
+ public bool MayReturn {
+ get {
+ return (Returns == FlowReturns.SOMETIMES) ||
+ (Returns == FlowReturns.ALWAYS);
+ }
+ }
+
+ // <summary>
+ // Merge a child branching.
+ // </summary>
+ public FlowReturns MergeChildren (FlowBranching branching, ICollection children)
+ {
+ MyBitVector new_locals = null;
+ MyBitVector new_params = null;
+
+ FlowReturns new_returns = FlowReturns.NEVER;
+ FlowReturns new_breaks = FlowReturns.NEVER;
+ bool new_returns_set = false, new_breaks_set = false;
+
+ Report.Debug (2, "MERGING CHILDREN", branching, branching.Type,
+ this, children.Count);
+
+ foreach (UsageVector child in children) {
+ Report.Debug (2, " MERGING CHILD", child, child.is_finally);
+
+ if (!child.is_finally) {
+ if (child.Breaks != FlowReturns.UNREACHABLE) {
+ // If Returns is already set, perform an
+ // `And' operation on it, otherwise just set just.
+ if (!new_returns_set) {
+ new_returns = child.Returns;
+ new_returns_set = true;
+ } else
+ new_returns = AndFlowReturns (
+ new_returns, child.Returns);
+ }
+
+ // If Breaks is already set, perform an
+ // `And' operation on it, otherwise just set just.
+ if (!new_breaks_set) {
+ new_breaks = child.Breaks;
+ new_breaks_set = true;
+ } else
+ new_breaks = AndFlowReturns (
+ new_breaks, child.Breaks);
+ }
+
+ // Ignore unreachable children.
+ if (child.Returns == FlowReturns.UNREACHABLE)
+ continue;
+
+ // A local variable is initialized after a flow branching if it
+ // has been initialized in all its branches which do neither
+ // always return or always throw an exception.
+ //
+ // If a branch may return, but does not always return, then we
+ // can treat it like a never-returning branch here: control will
+ // only reach the code position after the branching if we did not
+ // return here.
+ //
+ // It's important to distinguish between always and sometimes
+ // returning branches here:
+ //
+ // 1 int a;
+ // 2 if (something) {
+ // 3 return;
+ // 4 a = 5;
+ // 5 }
+ // 6 Console.WriteLine (a);
+ //
+ // The if block in lines 3-4 always returns, so we must not look
+ // at the initialization of `a' in line 4 - thus it'll still be
+ // uninitialized in line 6.
+ //
+ // On the other hand, the following is allowed:
+ //
+ // 1 int a;
+ // 2 if (something)
+ // 3 a = 5;
+ // 4 else
+ // 5 return;
+ // 6 Console.WriteLine (a);
+ //
+ // Here, `a' is initialized in line 3 and we must not look at
+ // line 5 since it always returns.
+ //
+ if (child.is_finally) {
+ if (new_locals == null)
+ new_locals = locals.Clone ();
+ new_locals.Or (child.locals);
+
+ if (parameters != null) {
+ if (new_params == null)
+ new_params = parameters.Clone ();
+ new_params.Or (child.parameters);
+ }
+
+ } else {
+ if (!child.AlwaysReturns && !child.AlwaysBreaks) {
+ if (new_locals != null)
+ new_locals.And (child.locals);
+ else {
+ new_locals = locals.Clone ();
+ new_locals.Or (child.locals);
+ }
+ } else if (children.Count == 1) {
+ new_locals = locals.Clone ();
+ new_locals.Or (child.locals);
+ }
+
+ // An `out' parameter must be assigned in all branches which do
+ // not always throw an exception.
+ if (parameters != null) {
+ if (child.Breaks != FlowReturns.EXCEPTION) {
+ if (new_params != null)
+ new_params.And (child.parameters);
+ else {
+ new_params = parameters.Clone ();
+ new_params.Or (child.parameters);
+ }
+ } else if (children.Count == 1) {
+ new_params = parameters.Clone ();
+ new_params.Or (child.parameters);
+ }
+ }
+ }
+ }
+
+ Returns = new_returns;
+ if ((branching.Type == FlowBranchingType.BLOCK) ||
+ (branching.Type == FlowBranchingType.EXCEPTION) ||
+ (new_breaks == FlowReturns.UNREACHABLE) ||
+ (new_breaks == FlowReturns.EXCEPTION))
+ Breaks = new_breaks;
+ else if (branching.Type == FlowBranchingType.SWITCH_SECTION)
+ Breaks = new_returns;
+ else if (branching.Type == FlowBranchingType.SWITCH){
+ if (new_breaks == FlowReturns.ALWAYS)
+ Breaks = FlowReturns.ALWAYS;
+ }
+
+ //
+ // We've now either reached the point after the branching or we will
+ // never get there since we always return or always throw an exception.
+ //
+ // If we can reach the point after the branching, mark all locals and
+ // parameters as initialized which have been initialized in all branches
+ // we need to look at (see above).
+ //
+
+ if (((new_breaks != FlowReturns.ALWAYS) &&
+ (new_breaks != FlowReturns.EXCEPTION) &&
+ (new_breaks != FlowReturns.UNREACHABLE)) ||
+ (children.Count == 1)) {
+ if (new_locals != null)
+ locals.Or (new_locals);
+
+ if (new_params != null)
+ parameters.Or (new_params);
+ }
+
+ Report.Debug (2, "MERGING CHILDREN DONE", branching.Type,
+ new_params, new_locals, new_returns, new_breaks,
+ branching.Infinite, branching.MayLeaveLoop, this);
+
+ if (branching.Type == FlowBranchingType.SWITCH_SECTION) {
+ if ((new_breaks != FlowReturns.ALWAYS) &&
+ (new_breaks != FlowReturns.EXCEPTION) &&
+ (new_breaks != FlowReturns.UNREACHABLE))
+ Report.Error (163, branching.Location,
+ "Control cannot fall through from one " +
+ "case label to another");
+ }
+
+ if (branching.Infinite && !branching.MayLeaveLoop) {
+ Report.Debug (1, "INFINITE", new_returns, new_breaks,
+ Returns, Breaks, this);
+
+ // We're actually infinite.
+ if (new_returns == FlowReturns.NEVER) {
+ Breaks = FlowReturns.UNREACHABLE;
+ return FlowReturns.UNREACHABLE;
+ }
+
+ // If we're an infinite loop and do not break, the code after
+ // the loop can never be reached. However, if we may return
+ // from the loop, then we do always return (or stay in the loop
+ // forever).
+ if ((new_returns == FlowReturns.SOMETIMES) ||
+ (new_returns == FlowReturns.ALWAYS)) {
+ Returns = FlowReturns.ALWAYS;
+ return FlowReturns.ALWAYS;
+ }
+ }
+
+ return new_returns;
+ }
+
+ // <summary>
+ // Tells control flow analysis that the current code position may be reached with
+ // a forward jump from any of the origins listed in `origin_vectors' which is a
+ // list of UsageVectors.
+ //
+ // This is used when resolving forward gotos - in the following example, the
+ // variable `a' is uninitialized in line 8 becase this line may be reached via
+ // the goto in line 4:
+ //
+ // 1 int a;
+ //
+ // 3 if (something)
+ // 4 goto World;
+ //
+ // 6 a = 5;
+ //
+ // 7 World:
+ // 8 Console.WriteLine (a);
+ //
+ // </summary>
+ public void MergeJumpOrigins (ICollection origin_vectors)
+ {
+ Report.Debug (1, "MERGING JUMP ORIGIN", this);
+
+ real_breaks = FlowReturns.NEVER;
+ real_returns = FlowReturns.NEVER;
+
+ foreach (UsageVector vector in origin_vectors) {
+ Report.Debug (1, " MERGING JUMP ORIGIN", vector);
+
+ locals.And (vector.locals);
+ if (parameters != null)
+ parameters.And (vector.parameters);
+ Breaks = AndFlowReturns (Breaks, vector.Breaks);
+ Returns = AndFlowReturns (Returns, vector.Returns);
+ }
+
+ Report.Debug (1, "MERGING JUMP ORIGIN DONE", this);
+ }
+
+ // <summary>
+ // This is used at the beginning of a finally block if there were
+ // any return statements in the try block or one of the catch blocks.
+ // </summary>
+ public void MergeFinallyOrigins (ICollection finally_vectors)
+ {
+ Report.Debug (1, "MERGING FINALLY ORIGIN", this);
+
+ real_breaks = FlowReturns.NEVER;
+
+ foreach (UsageVector vector in finally_vectors) {
+ Report.Debug (1, " MERGING FINALLY ORIGIN", vector);
+
+ if (parameters != null)
+ parameters.And (vector.parameters);
+ Breaks = AndFlowReturns (Breaks, vector.Breaks);
+ }
+
+ is_finally = true;
+
+ Report.Debug (1, "MERGING FINALLY ORIGIN DONE", this);
+ }
+
+ public void CheckOutParameters (FlowBranching branching)
+ {
+ if (parameters != null)
+ branching.CheckOutParameters (parameters, branching.Location);
+ }
+
+ // <summary>
+ // Performs an `or' operation on the locals and the parameters.
+ // </summary>
+ public void Or (UsageVector new_vector)
+ {
+ locals.Or (new_vector.locals);
+ if (parameters != null)
+ parameters.Or (new_vector.parameters);
+ }
+
+ // <summary>
+ // Performs an `and' operation on the locals.
+ // </summary>
+ public void AndLocals (UsageVector new_vector)
+ {
+ locals.And (new_vector.locals);
+ }
+
+ // <summary>
+ // Returns a deep copy of the parameters.
+ // </summary>
+ public MyBitVector Parameters {
+ get {
+ if (parameters != null)
+ return parameters.Clone ();
+ else
+ return null;
+ }
+ }
+
+ // <summary>
+ // Returns a deep copy of the locals.
+ // </summary>
+ public MyBitVector Locals {
+ get {
+ return locals.Clone ();
+ }
+ }
+
+ //
+ // Debugging stuff.
+ //
+
+ public override string ToString ()
+ {
+ StringBuilder sb = new StringBuilder ();
+
+ sb.Append ("Vector (");
+ sb.Append (id);
+ sb.Append (",");
+ sb.Append (Returns);
+ sb.Append (",");
+ sb.Append (Breaks);
+ if (parameters != null) {
+ sb.Append (" - ");
+ sb.Append (parameters);
+ }
+ sb.Append (" - ");
+ sb.Append (locals);
+ sb.Append (")");
+
+ return sb.ToString ();
+ }
+ }
+
+ FlowBranching (FlowBranchingType type, Location loc)
+ {
+ this.Siblings = new ArrayList ();
+ this.Block = null;
+ this.Location = loc;
+ this.Type = type;
+ id = ++next_id;
+ }
+
+ // <summary>
+ // Creates a new flow branching for `block'.
+ // This is used from Block.Resolve to create the top-level branching of
+ // the block.
+ // </summary>
+ public FlowBranching (Block block, InternalParameters ip, Location loc)
+ : this (FlowBranchingType.BLOCK, loc)
+ {
+ Block = block;
+ Parent = null;
+
+ int count = (ip != null) ? ip.Count : 0;
+
+ param_info = ip;
+ param_map = new int [count];
+ struct_params = new MyStructInfo [count];
+ num_params = 0;
+
+ for (int i = 0; i < count; i++) {
+ Parameter.Modifier mod = param_info.ParameterModifier (i);
+
+ if ((mod & Parameter.Modifier.OUT) == 0)
+ continue;
+
+ param_map [i] = ++num_params;
+
+ Type param_type = param_info.ParameterType (i);
+
+ struct_params [i] = MyStructInfo.GetStructInfo (param_type);
+ if (struct_params [i] != null)
+ num_params += struct_params [i].Count;
+ }
+
+ Siblings = new ArrayList ();
+ Siblings.Add (new UsageVector (null, num_params, block.CountVariables));
+ }
+
+ // <summary>
+ // Creates a new flow branching which is contained in `parent'.
+ // You should only pass non-null for the `block' argument if this block
+ // introduces any new variables - in this case, we need to create a new
+ // usage vector with a different size than our parent's one.
+ // </summary>
+ public FlowBranching (FlowBranching parent, FlowBranchingType type,
+ Block block, Location loc)
+ : this (type, loc)
+ {
+ Parent = parent;
+ Block = block;
+
+ if (parent != null) {
+ param_info = parent.param_info;
+ param_map = parent.param_map;
+ struct_params = parent.struct_params;
+ num_params = parent.num_params;
+ }
+
+ UsageVector vector;
+ if (Block != null)
+ vector = new UsageVector (parent.CurrentUsageVector, num_params,
+ Block.CountVariables);
+ else
+ vector = new UsageVector (Parent.CurrentUsageVector);
+
+ Siblings.Add (vector);
+
+ switch (Type) {
+ case FlowBranchingType.EXCEPTION:
+ finally_vectors = new ArrayList ();
+ break;
+
+ default:
+ break;
+ }
+ }
+
+ // <summary>
+ // Returns the branching's current usage vector.
+ // </summary>
+ public UsageVector CurrentUsageVector
+ {
+ get {
+ return (UsageVector) Siblings [Siblings.Count - 1];
+ }
+ }
+
+ // <summary>
+ // Creates a sibling of the current usage vector.
+ // </summary>
+ public void CreateSibling ()
+ {
+ Siblings.Add (new UsageVector (Parent.CurrentUsageVector));
+
+ Report.Debug (1, "CREATED SIBLING", CurrentUsageVector);
+ }
+
+ // <summary>
+ // Creates a sibling for a `finally' block.
+ // </summary>
+ public void CreateSiblingForFinally ()
+ {
+ if (Type != FlowBranchingType.EXCEPTION)
+ throw new NotSupportedException ();
+
+ CreateSibling ();
+
+ CurrentUsageVector.MergeFinallyOrigins (finally_vectors);
+ }
+
+ // <summary>
+ // Check whether all `out' parameters have been assigned.
+ // </summary>
+ public void CheckOutParameters (MyBitVector parameters, Location loc)
+ {
+ if (InTryBlock ())
+ return;
+
+ for (int i = 0; i < param_map.Length; i++) {
+ int index = param_map [i];
+
+ if (index == 0)
+ continue;
+
+ if (parameters [index - 1])
+ continue;
+
+ // If it's a struct, we must ensure that all its fields have
+ // been assigned. If the struct has any non-public fields, this
+ // can only be done by assigning the whole struct.
+
+ MyStructInfo struct_info = struct_params [index - 1];
+ if ((struct_info == null) || struct_info.HasNonPublicFields) {
+ Report.Error (
+ 177, loc, "The out parameter `" +
+ param_info.ParameterName (i) + "' must be " +
+ "assigned before control leave the current method.");
+ param_map [i] = 0;
+ continue;
+ }
+
+
+ for (int j = 0; j < struct_info.Count; j++) {
+ if (!parameters [index + j]) {
+ Report.Error (
+ 177, loc, "The out parameter `" +
+ param_info.ParameterName (i) + "' must be " +
+ "assigned before control leave the current method.");
+ param_map [i] = 0;
+ break;
+ }
+ }
+ }
+ }
+
+ // <summary>
+ // Merge a child branching.
+ // </summary>
+ public FlowReturns MergeChild (FlowBranching child)
+ {
+ FlowReturns returns = CurrentUsageVector.MergeChildren (child, child.Siblings);
+
+ if (child.Type != FlowBranchingType.LOOP_BLOCK)
+ MayLeaveLoop |= child.MayLeaveLoop;
+ else
+ MayLeaveLoop = false;
+
+ return returns;
+ }
+
+ // <summary>
+ // Does the toplevel merging.
+ // </summary>
+ public FlowReturns MergeTopBlock ()
+ {
+ if ((Type != FlowBranchingType.BLOCK) || (Block == null))
+ throw new NotSupportedException ();
+
+ UsageVector vector = new UsageVector (null, num_params, Block.CountVariables);
+
+ Report.Debug (1, "MERGING TOP BLOCK", Location, vector);
+
+ vector.MergeChildren (this, Siblings);
+
+ Siblings.Clear ();
+ Siblings.Add (vector);
+
+ Report.Debug (1, "MERGING TOP BLOCK DONE", Location, vector);
+
+ if (vector.Breaks != FlowReturns.EXCEPTION) {
+ if (!vector.AlwaysBreaks)
+ CheckOutParameters (CurrentUsageVector.Parameters, Location);
+ return vector.AlwaysBreaks ? FlowReturns.ALWAYS : vector.Returns;
+ } else
+ return FlowReturns.EXCEPTION;
+ }
+
+ public bool InTryBlock ()
+ {
+ if (finally_vectors != null)
+ return true;
+ else if (Parent != null)
+ return Parent.InTryBlock ();
+ else
+ return false;
+ }
+
+ public void AddFinallyVector (UsageVector vector)
+ {
+ if (finally_vectors != null) {
+ finally_vectors.Add (vector.Clone ());
+ return;
+ }
+
+ if (Parent != null)
+ Parent.AddFinallyVector (vector);
+ else
+ throw new NotSupportedException ();
+ }
+
+ public bool IsVariableAssigned (VariableInfo vi)
+ {
+ if (CurrentUsageVector.AlwaysBreaks)
+ return true;
+ else
+ return CurrentUsageVector [vi, 0];
+ }
+
+ public bool IsVariableAssigned (VariableInfo vi, int field_idx)
+ {
+ if (CurrentUsageVector.AlwaysBreaks)
+ return true;
+ else
+ return CurrentUsageVector [vi, field_idx];
+ }
+
+ public void SetVariableAssigned (VariableInfo vi)
+ {
+ if (CurrentUsageVector.AlwaysBreaks)
+ return;
+
+ CurrentUsageVector [vi, 0] = true;
+ }
+
+ public void SetVariableAssigned (VariableInfo vi, int field_idx)
+ {
+ if (CurrentUsageVector.AlwaysBreaks)
+ return;
+
+ CurrentUsageVector [vi, field_idx] = true;
+ }
+
+ public bool IsParameterAssigned (int number)
+ {
+ int index = param_map [number];
+
+ if (index == 0)
+ return true;
+
+ if (CurrentUsageVector [index])
+ return true;
+
+ // Parameter is not assigned, so check whether it's a struct.
+ // If it's either not a struct or a struct which non-public
+ // fields, return false.
+ MyStructInfo struct_info = struct_params [number];
+ if ((struct_info == null) || struct_info.HasNonPublicFields)
+ return false;
+
+ // Ok, so each field must be assigned.
+ for (int i = 0; i < struct_info.Count; i++)
+ if (!CurrentUsageVector [index + i])
+ return false;
+
+ return true;
+ }
+
+ public bool IsParameterAssigned (int number, string field_name)
+ {
+ int index = param_map [number];
+
+ if (index == 0)
+ return true;
+
+ MyStructInfo info = (MyStructInfo) struct_params [number];
+ if (info == null)
+ return true;
+
+ int field_idx = info [field_name];
+
+ return CurrentUsageVector [index + field_idx];
+ }
+
+ public void SetParameterAssigned (int number)
+ {
+ if (param_map [number] == 0)
+ return;
+
+ if (!CurrentUsageVector.AlwaysBreaks)
+ CurrentUsageVector [param_map [number]] = true;
+ }
+
+ public void SetParameterAssigned (int number, string field_name)
+ {
+ int index = param_map [number];
+
+ if (index == 0)
+ return;
+
+ MyStructInfo info = (MyStructInfo) struct_params [number];
+ if (info == null)
+ return;
+
+ int field_idx = info [field_name];
+
+ if (!CurrentUsageVector.AlwaysBreaks)
+ CurrentUsageVector [index + field_idx] = true;
+ }
+
+ public bool IsReachable ()
+ {
+ bool reachable;
+
+ switch (Type) {
+ case FlowBranchingType.SWITCH_SECTION:
+ // The code following a switch block is reachable unless the switch
+ // block always returns.
+ reachable = !CurrentUsageVector.AlwaysReturns;
+ break;
+
+ case FlowBranchingType.LOOP_BLOCK:
+ // The code following a loop is reachable unless the loop always
+ // returns or it's an infinite loop without any `break's in it.
+ reachable = !CurrentUsageVector.AlwaysReturns &&
+ (CurrentUsageVector.Breaks != FlowReturns.UNREACHABLE);
+ break;
+
+ default:
+ // The code following a block or exception is reachable unless the
+ // block either always returns or always breaks.
+ reachable = !CurrentUsageVector.AlwaysBreaks &&
+ !CurrentUsageVector.AlwaysReturns;
+ break;
+ }
+
+ Report.Debug (1, "REACHABLE", Type, CurrentUsageVector.Returns,
+ CurrentUsageVector.Breaks, CurrentUsageVector, reachable);
+
+ return reachable;
+ }
+
+ public override string ToString ()
+ {
+ StringBuilder sb = new StringBuilder ("FlowBranching (");
+
+ sb.Append (id);
+ sb.Append (",");
+ sb.Append (Type);
+ if (Block != null) {
+ sb.Append (" - ");
+ sb.Append (Block.ID);
+ sb.Append (" - ");
+ sb.Append (Block.StartLocation);
+ }
+ sb.Append (" - ");
+ sb.Append (Siblings.Count);
+ sb.Append (" - ");
+ sb.Append (CurrentUsageVector);
+ sb.Append (")");
+ return sb.ToString ();
+ }
+ }
+
+ public class MyStructInfo {
+ public readonly Type Type;
+ public readonly FieldInfo[] Fields;
+ public readonly FieldInfo[] NonPublicFields;
+ public readonly int Count;
+ public readonly int CountNonPublic;
+ public readonly bool HasNonPublicFields;
+
+ private static Hashtable field_type_hash = new Hashtable ();
+ private Hashtable field_hash;
+
+ // Private constructor. To save memory usage, we only need to create one instance
+ // of this class per struct type.
+ private MyStructInfo (Type type)
+ {
+ this.Type = type;
+
+ if (type is TypeBuilder) {
+ TypeContainer tc = TypeManager.LookupTypeContainer (type);
+
+ ArrayList fields = tc.Fields;
+ if (fields != null) {
+ foreach (Field field in fields) {
+ if ((field.ModFlags & Modifiers.STATIC) != 0)
+ continue;
+ if ((field.ModFlags & Modifiers.PUBLIC) != 0)
+ ++Count;
+ else
+ ++CountNonPublic;
+ }
+ }
+
+ Fields = new FieldInfo [Count];
+ NonPublicFields = new FieldInfo [CountNonPublic];
+
+ Count = CountNonPublic = 0;
+ if (fields != null) {
+ foreach (Field field in fields) {
+ if ((field.ModFlags & Modifiers.STATIC) != 0)
+ continue;
+ if ((field.ModFlags & Modifiers.PUBLIC) != 0)
+ Fields [Count++] = field.FieldBuilder;
+ else
+ NonPublicFields [CountNonPublic++] =
+ field.FieldBuilder;
+ }
+ }
+
+ } else {
+ Fields = type.GetFields (BindingFlags.Instance|BindingFlags.Public);
+ Count = Fields.Length;
+
+ NonPublicFields = type.GetFields (BindingFlags.Instance|BindingFlags.NonPublic);
+ CountNonPublic = NonPublicFields.Length;
+ }
+
+ Count += NonPublicFields.Length;
+
+ int number = 0;
+ field_hash = new Hashtable ();
+ foreach (FieldInfo field in Fields)
+ field_hash.Add (field.Name, ++number);
+
+ if (NonPublicFields.Length != 0)
+ HasNonPublicFields = true;
+
+ foreach (FieldInfo field in NonPublicFields)
+ field_hash.Add (field.Name, ++number);
+ }
+
+ public int this [string name] {
+ get {
+ if (field_hash.Contains (name))
+ return (int) field_hash [name];
+ else
+ return 0;
+ }
+ }
+
+ public FieldInfo this [int index] {
+ get {
+ if (index >= Fields.Length)
+ return NonPublicFields [index - Fields.Length];
+ else
+ return Fields [index];
+ }
+ }
+
+ public static MyStructInfo GetStructInfo (Type type)
+ {
+ if (!TypeManager.IsValueType (type) || TypeManager.IsEnumType (type))
+ return null;
+
+ if (!(type is TypeBuilder) && TypeManager.IsBuiltinType (type))
+ return null;
+
+ MyStructInfo info = (MyStructInfo) field_type_hash [type];
+ if (info != null)
+ return info;
+
+ info = new MyStructInfo (type);
+ field_type_hash.Add (type, info);
+ return info;
+ }
+
+ public static MyStructInfo GetStructInfo (TypeContainer tc)
+ {
+ MyStructInfo info = (MyStructInfo) field_type_hash [tc.TypeBuilder];
+ if (info != null)
+ return info;
+
+ info = new MyStructInfo (tc.TypeBuilder);
+ field_type_hash.Add (tc.TypeBuilder, info);
+ return info;
+ }
+ }
+
+ public class VariableInfo : IVariable {
+ public Expression Type;
+ public LocalBuilder LocalBuilder;
+ public Type VariableType;
+ public readonly string Name;
+ public readonly Location Location;
+ public readonly int Block;
+
+ public int Number;
+
+ public bool Used;
+ public bool Assigned;
+ public bool ReadOnly;
+
+ public VariableInfo (Expression type, string name, int block, Location l)
+ {
+ Type = type;
+ Name = name;
+ Block = block;
+ LocalBuilder = null;
+ Location = l;
+ }
+
+ public VariableInfo (TypeContainer tc, int block, Location l)
+ {
+ VariableType = tc.TypeBuilder;
+ struct_info = MyStructInfo.GetStructInfo (tc);
+ Block = block;
+ LocalBuilder = null;
+ Location = l;
+ }
+
+ MyStructInfo struct_info;
+ public MyStructInfo StructInfo {
+ get {
+ return struct_info;
+ }
+ }
+
+ public bool IsAssigned (EmitContext ec, Location loc)
+ {
+ if (!ec.DoFlowAnalysis || ec.CurrentBranching.IsVariableAssigned (this))
+ return true;
+
+ MyStructInfo struct_info = StructInfo;
+ if ((struct_info == null) || (struct_info.HasNonPublicFields && (Name != null))) {
+ Report.Error (165, loc, "Use of unassigned local variable `" + Name + "'");
+ ec.CurrentBranching.SetVariableAssigned (this);
+ return false;
+ }
+
+ int count = struct_info.Count;
+
+ for (int i = 0; i < count; i++) {
+ if (!ec.CurrentBranching.IsVariableAssigned (this, i+1)) {
+ if (Name != null) {
+ Report.Error (165, loc,
+ "Use of unassigned local variable `" +
+ Name + "'");
+ ec.CurrentBranching.SetVariableAssigned (this);
+ return false;
+ }
+
+ FieldInfo field = struct_info [i];
+ Report.Error (171, loc,
+ "Field `" + TypeManager.CSharpName (VariableType) +
+ "." + field.Name + "' must be fully initialized " +
+ "before control leaves the constructor");
+ return false;
+ }
+ }
+
+ return true;
+ }
+
+ public bool IsFieldAssigned (EmitContext ec, string name, Location loc)
+ {
+ if (!ec.DoFlowAnalysis || ec.CurrentBranching.IsVariableAssigned (this) ||
+ (struct_info == null))
+ return true;
+
+ int field_idx = StructInfo [name];
+ if (field_idx == 0)
+ return true;
+
+ if (!ec.CurrentBranching.IsVariableAssigned (this, field_idx)) {
+ Report.Error (170, loc,
+ "Use of possibly unassigned field `" + name + "'");
+ ec.CurrentBranching.SetVariableAssigned (this, field_idx);
+ return false;
+ }
+
+ return true;
+ }
+
+ public void SetAssigned (EmitContext ec)
+ {
+ if (ec.DoFlowAnalysis)
+ ec.CurrentBranching.SetVariableAssigned (this);
+ }
+
+ public void SetFieldAssigned (EmitContext ec, string name)
+ {
+ if (ec.DoFlowAnalysis && (struct_info != null))
+ ec.CurrentBranching.SetVariableAssigned (this, StructInfo [name]);
+ }
+
+ public bool Resolve (DeclSpace decl)
+ {
+ if (struct_info != null)
+ return true;
+
+ if (VariableType == null)
+ VariableType = decl.ResolveType (Type, false, Location);
+
+ if (VariableType == null)
+ return false;
+
+ struct_info = MyStructInfo.GetStructInfo (VariableType);
+
+ return true;
+ }
+
+ public void MakePinned ()
{
TypeManager.MakePinned (LocalBuilder);
- }
+ }
+
+ public override string ToString ()
+ {
+ return "VariableInfo (" + Number + "," + Type + "," + Location + ")";
+ }
}
/// <summary>
: this (parent, implicit_block, Location.Null, Location.Null)
{ }
+ public Block (Block parent, bool implicit_block, Parameters parameters)
+ : this (parent, implicit_block, parameters, Location.Null, Location.Null)
+ { }
+
public Block (Block parent, Location start, Location end)
: this (parent, false, start, end)
{ }
+ public Block (Block parent, Parameters parameters, Location start, Location end)
+ : this (parent, false, parameters, start, end)
+ { }
+
public Block (Block parent, bool implicit_block, Location start, Location end)
+ : this (parent, implicit_block, Parameters.EmptyReadOnlyParameters,
+ start, end)
+ { }
+
+ public Block (Block parent, bool implicit_block, Parameters parameters,
+ Location start, Location end)
{
if (parent != null)
parent.AddChild (this);
this.Parent = parent;
this.Implicit = implicit_block;
+ this.parameters = parameters;
this.StartLocation = start;
this.EndLocation = end;
this.loc = start;
return this_id;
}
}
-
+
void AddChild (Block b)
{
if (children == null)
return true;
}
- public LabeledStatement LookupLabel (string name)
+ public LabeledStatement LookupLabel (string name)
+ {
+ if (labels != null){
+ if (labels.Contains (name))
+ return ((LabeledStatement) labels [name]);
+ }
+
+ if (Parent != null)
+ return Parent.LookupLabel (name);
+
+ return null;
+ }
+
+ VariableInfo this_variable = null;
+
+ // <summary>
+ // Returns the "this" instance variable of this block.
+ // See AddThisVariable() for more information.
+ // </summary>
+ public VariableInfo ThisVariable {
+ get {
+ if (this_variable != null)
+ return this_variable;
+ else if (Parent != null)
+ return Parent.ThisVariable;
+ else
+ return null;
+ }
+ }
+
+ Hashtable child_variable_names;
+
+ // <summary>
+ // Marks a variable with name @name as being used in a child block.
+ // If a variable name has been used in a child block, it's illegal to
+ // declare a variable with the same name in the current block.
+ // </summary>
+ public void AddChildVariableName (string name)
+ {
+ if (child_variable_names == null)
+ child_variable_names = new Hashtable ();
+
+ if (!child_variable_names.Contains (name))
+ child_variable_names.Add (name, true);
+ }
+
+ // <summary>
+ // Marks all variables from block @block and all its children as being
+ // used in a child block.
+ // </summary>
+ public void AddChildVariableNames (Block block)
+ {
+ if (block.Variables != null) {
+ foreach (string name in block.Variables.Keys)
+ AddChildVariableName (name);
+ }
+
+ foreach (Block child in block.children) {
+ if (child.Variables != null) {
+ foreach (string name in child.Variables.Keys)
+ AddChildVariableName (name);
+ }
+ }
+ }
+
+ // <summary>
+ // Checks whether a variable name has already been used in a child block.
+ // </summary>
+ public bool IsVariableNameUsedInChildBlock (string name)
+ {
+ if (child_variable_names == null)
+ return false;
+
+ return child_variable_names.Contains (name);
+ }
+
+ // <summary>
+ // This is used by non-static `struct' constructors which do not have an
+ // initializer - in this case, the constructor must initialize all of the
+ // struct's fields. To do this, we add a "this" variable and use the flow
+ // analysis code to ensure that it's been fully initialized before control
+ // leaves the constructor.
+ // </summary>
+ public VariableInfo AddThisVariable (TypeContainer tc, Location l)
{
- if (labels != null){
- if (labels.Contains (name))
- return ((LabeledStatement) labels [name]);
- }
+ if (this_variable != null)
+ return this_variable;
- if (Parent != null)
- return Parent.LookupLabel (name);
+ this_variable = new VariableInfo (tc, ID, l);
- return null;
+ if (variables == null)
+ variables = new Hashtable ();
+ variables.Add ("this", this_variable);
+
+ return this_variable;
}
- public VariableInfo AddVariable (string type, string name, Parameters pars, Location l)
+ public VariableInfo AddVariable (Expression type, string name, Parameters pars, Location l)
{
if (variables == null)
variables = new Hashtable ();
- if (GetVariableType (name) != null)
+ VariableInfo vi = GetVariableInfo (name);
+ if (vi != null) {
+ if (vi.Block != ID)
+ Report.Error (136, l, "A local variable named `" + name + "' " +
+ "cannot be declared in this scope since it would " +
+ "give a different meaning to `" + name + "', which " +
+ "is already used in a `parent or current' scope to " +
+ "denote something else");
+ else
+ Report.Error (128, l, "A local variable `" + name + "' is already " +
+ "defined in this scope");
+ return null;
+ }
+
+ if (IsVariableNameUsedInChildBlock (name)) {
+ Report.Error (136, l, "A local variable named `" + name + "' " +
+ "cannot be declared in this scope since it would " +
+ "give a different meaning to `" + name + "', which " +
+ "is already used in a `child' scope to denote something " +
+ "else");
return null;
+ }
if (pars != null) {
int idx = 0;
Parameter p = pars.GetParameterByName (name, out idx);
- if (p != null)
+ if (p != null) {
+ Report.Error (136, l, "A local variable named `" + name + "' " +
+ "cannot be declared in this scope since it would " +
+ "give a different meaning to `" + name + "', which " +
+ "is already used in a `parent or current' scope to " +
+ "denote something else");
return null;
+ }
}
- VariableInfo vi = new VariableInfo (type, l);
+ vi = new VariableInfo (type, name, ID, l);
variables.Add (name, vi);
+ if (variables_initialized)
+ throw new Exception ();
+
// Console.WriteLine ("Adding {0} to {1}", name, ID);
return vi;
}
- public bool AddConstant (string type, string name, Expression value, Parameters pars, Location l)
+ public bool AddConstant (Expression type, string name, Expression value, Parameters pars, Location l)
{
if (AddVariable (type, name, pars, l) == null)
return false;
return null;
}
- public string GetVariableType (string name)
+ public Expression GetVariableType (string name)
{
VariableInfo vi = GetVariableInfo (name);
return null;
}
- /// <summary>
- /// True if the variable named @name has been defined
- /// in this block
- /// </summary>
- public bool IsVariableDefined (string name)
- {
- // Console.WriteLine ("Looking up {0} in {1}", name, ID);
- if (variables != null) {
- if (variables.Contains (name))
- return true;
- }
-
- if (Parent != null)
- return Parent.IsVariableDefined (name);
-
- return false;
- }
-
/// <summary>
/// True if the variable named @name is a constant
/// </summary>
}
}
+ Parameters parameters = null;
+ public Parameters Parameters {
+ get {
+ if (Parent != null)
+ return Parent.Parameters;
+
+ return parameters;
+ }
+ }
+
/// <returns>
/// A list of labels that were not used within this block
/// </returns>
{
used = true;
}
-
+
+ bool variables_initialized = false;
+ int count_variables = 0, first_variable = 0;
+
+ void UpdateVariableInfo (EmitContext ec)
+ {
+ DeclSpace ds = ec.DeclSpace;
+
+ first_variable = 0;
+
+ if (Parent != null)
+ first_variable += Parent.CountVariables;
+
+ count_variables = first_variable;
+ if (variables != null) {
+ foreach (VariableInfo vi in variables.Values) {
+ if (!vi.Resolve (ds)) {
+ vi.Number = -1;
+ continue;
+ }
+
+ vi.Number = ++count_variables;
+
+ if (vi.StructInfo != null)
+ count_variables += vi.StructInfo.Count;
+ }
+ }
+
+ variables_initialized = true;
+ }
+
+ //
+ // <returns>
+ // The number of local variables in this block
+ // </returns>
+ public int CountVariables
+ {
+ get {
+ if (!variables_initialized)
+ throw new Exception ();
+
+ return count_variables;
+ }
+ }
+
/// <summary>
/// Emits the variable declarations and labels.
/// </summary>
{
DeclSpace ds = ec.DeclSpace;
ILGenerator ig = ec.ig;
-
+
+ if (!variables_initialized)
+ UpdateVariableInfo (ec);
+
//
// Process this block variables
//
foreach (DictionaryEntry de in variables){
string name = (string) de.Key;
VariableInfo vi = (VariableInfo) de.Value;
- Type t;
- t = RootContext.LookupType (ds, vi.Type, false, vi.Location);
- if (t == null)
+ if (vi.VariableType == null)
continue;
- vi.VariableType = t;
- vi.LocalBuilder = ig.DeclareLocal (t);
+ vi.LocalBuilder = ig.DeclareLocal (vi.VariableType);
if (CodeGen.SymbolWriter != null)
vi.LocalBuilder.SetLocalSymInfo (name);
b.UsageWarning ();
}
+ bool has_ret = false;
+
public override bool Resolve (EmitContext ec)
{
Block prev_block = ec.CurrentBlock;
+ bool ok = true;
ec.CurrentBlock = this;
- foreach (Statement s in statements){
- if (s.Resolve (ec) == false){
- ec.CurrentBlock = prev_block;
- return false;
+ ec.StartFlowBranching (this);
+
+ Report.Debug (1, "RESOLVE BLOCK", StartLocation, ec.CurrentBranching);
+
+ if (!variables_initialized)
+ UpdateVariableInfo (ec);
+
+ ArrayList new_statements = new ArrayList ();
+ bool unreachable = false, warning_shown = false;
+
+ foreach (Statement s in statements){
+ if (unreachable && !(s is LabeledStatement)) {
+ if (!warning_shown && !(s is EmptyStatement)) {
+ warning_shown = true;
+ Warning_DeadCodeFound (s.loc);
+ }
+
+ continue;
+ }
+
+ if (s.Resolve (ec) == false) {
+ ok = false;
+ continue;
}
+
+ if (s is LabeledStatement)
+ unreachable = false;
+ else
+ unreachable = ! ec.CurrentBranching.IsReachable ();
+
+ new_statements.Add (s);
}
+ statements = new_statements;
+
+ Report.Debug (1, "RESOLVE BLOCK DONE", StartLocation, ec.CurrentBranching);
+
+ FlowReturns returns = ec.EndFlowBranching ();
ec.CurrentBlock = prev_block;
- return true;
+
+ // If we're a non-static `struct' constructor which doesn't have an
+ // initializer, then we must initialize all of the struct's fields.
+ if ((this_variable != null) && (returns != FlowReturns.EXCEPTION) &&
+ !this_variable.IsAssigned (ec, loc))
+ ok = false;
+
+ if ((labels != null) && (RootContext.WarningLevel >= 2)) {
+ foreach (LabeledStatement label in labels.Values)
+ if (!label.HasBeenReferenced)
+ Report.Warning (164, label.Location,
+ "This label has not been referenced");
+ }
+
+ if ((returns == FlowReturns.ALWAYS) ||
+ (returns == FlowReturns.EXCEPTION) ||
+ (returns == FlowReturns.UNREACHABLE))
+ has_ret = true;
+
+ return ok;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
- bool is_ret = false;
Block prev_block = ec.CurrentBlock;
-
- ec.CurrentBlock = this;
- if (CodeGen.SymbolWriter != null) {
- ec.Mark (StartLocation);
-
- foreach (Statement s in statements) {
- ec.Mark (s.loc);
-
- is_ret = s.Emit (ec);
- }
+ ec.CurrentBlock = this;
- ec.Mark (EndLocation);
- } else {
- foreach (Statement s in statements)
- is_ret = s.Emit (ec);
- }
+ ec.Mark (StartLocation);
+ foreach (Statement s in statements)
+ s.Emit (ec);
+ ec.Mark (EndLocation);
ec.CurrentBlock = prev_block;
- return is_ret;
+ return has_ret;
}
}
public Location loc;
public Label ILLabel;
public Label ILLabelCode;
-
+
//
// if expr == null, then it is the default case.
//
return converted;
}
}
-
+
//
// Resolves the expression, reduces it to a literal if possible
// and then converts it to the requested type.
if (e is StringConstant || e is NullLiteral){
if (required_type == TypeManager.string_type){
- converted = label;
+ converted = e;
ILLabel = ec.ig.DefineLabel ();
return true;
}
//
bool got_default;
Label default_target;
-
+ Expression new_expr;
+
//
// The types allowed to be implicitly cast from
// on the governing type
fFoundDefault = true;
}
}
- fAllReturn &= ss.Block.Emit (ec);
+ bool returns = ss.Block.Emit (ec);
+ fAllReturn &= returns;
//ig.Emit (OpCodes.Br, lblEnd);
}
- if (!fFoundDefault)
+ if (!fFoundDefault) {
ig.MarkLabel (lblDefault);
+ fAllReturn = false;
+ }
ig.MarkLabel (lblEnd);
return fAllReturn;
ig.Emit (OpCodes.Call, TypeManager.string_isinterneted_string);
ig.Emit (OpCodes.Stloc, val);
}
-
- SwitchSection last_section;
- last_section = (SwitchSection) Sections [Sections.Count-1];
foreach (SwitchSection ss in Sections){
Label sec_begin = ig.DefineLabel ();
}
}
}
- if (label_count != 1 && ss != last_section)
+ if (label_count != 1)
ig.Emit (OpCodes.Br, next_test);
if (null_found)
ig.MarkLabel (null_target);
ig.MarkLabel (sec_begin);
- foreach (SwitchLabel sl in ss.Labels)\r
+ foreach (SwitchLabel sl in ss.Labels)
ig.MarkLabel (sl.ILLabelCode);
- if (ss.Block.Emit (ec))
+
+ bool returns = ss.Block.Emit (ec);
+ if (returns)
pending_goto_end = false;
else {
all_return = false;
}
public override bool Resolve (EmitContext ec)
- {
- foreach (SwitchSection ss in Sections){
- if (ss.Block.Resolve (ec) != true)
- return false;
- }
-
- return true;
- }
-
- public override bool Emit (EmitContext ec)
{
Expr = Expr.Resolve (ec);
if (Expr == null)
return false;
- Expression new_expr = SwitchGoverningType (ec, Expr.Type);
+ new_expr = SwitchGoverningType (ec, Expr.Type);
if (new_expr == null){
Report.Error (151, loc, "An integer type or string was expected for switch");
return false;
if (!CheckSwitch (ec))
return false;
+ Switch old_switch = ec.Switch;
+ ec.Switch = this;
+ ec.Switch.SwitchType = SwitchType;
+
+ ec.StartFlowBranching (FlowBranchingType.SWITCH, loc);
+
+ bool first = true;
+ foreach (SwitchSection ss in Sections){
+ if (!first)
+ ec.CurrentBranching.CreateSibling ();
+ else
+ first = false;
+
+ if (ss.Block.Resolve (ec) != true)
+ return false;
+ }
+
+
+ if (!got_default)
+ ec.CurrentBranching.CreateSibling ();
+
+ ec.EndFlowBranching ();
+ ec.Switch = old_switch;
+
+ return true;
+ }
+
+ protected override bool DoEmit (EmitContext ec)
+ {
// Store variable for comparission purposes
LocalBuilder value = ec.ig.DeclareLocal (SwitchType);
new_expr.Emit (ec);
return Statement.Resolve (ec) && expr != null;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
Type type = expr.Type;
bool val;
return Block.Resolve (ec);
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
bool previous_state = ec.CheckState;
bool previous_state_const = ec.ConstantCheckState;
public override bool Resolve (EmitContext ec)
{
- return Block.Resolve (ec);
+ bool previous_state = ec.CheckState;
+ bool previous_state_const = ec.ConstantCheckState;
+
+ ec.CheckState = true;
+ ec.ConstantCheckState = true;
+ bool ret = Block.Resolve (ec);
+ ec.CheckState = previous_state;
+ ec.ConstantCheckState = previous_state_const;
+
+ return ret;
}
-
- public override bool Emit (EmitContext ec)
+
+ protected override bool DoEmit (EmitContext ec)
{
bool previous_state = ec.CheckState;
bool previous_state_const = ec.ConstantCheckState;
public override bool Resolve (EmitContext ec)
{
- return Block.Resolve (ec);
+ bool previous_state = ec.InUnsafe;
+ bool val;
+
+ ec.InUnsafe = true;
+ val = Block.Resolve (ec);
+ ec.InUnsafe = previous_state;
+
+ return val;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
bool previous_state = ec.InUnsafe;
bool val;
// Fixed statement
//
public class Fixed : Statement {
- string type;
+ Expression type;
ArrayList declarators;
Statement statement;
+ Type expr_type;
+ FixedData[] data;
- public Fixed (string type, ArrayList decls, Statement stmt, Location l)
+ struct FixedData {
+ public bool is_object;
+ public VariableInfo vi;
+ public Expression expr;
+ public Expression converted;
+ }
+
+ public Fixed (Expression type, ArrayList decls, Statement stmt, Location l)
{
this.type = type;
declarators = decls;
public override bool Resolve (EmitContext ec)
{
- return statement.Resolve (ec);
- }
-
- public override bool Emit (EmitContext ec)
- {
- ILGenerator ig = ec.ig;
- Type t;
-
- t = RootContext.LookupType (ec.DeclSpace, type, false, loc);
- if (t == null)
+ expr_type = ec.DeclSpace.ResolveType (type, false, loc);
+ if (expr_type == null)
return false;
- bool is_ret = false;
+ data = new FixedData [declarators.Count];
+ int i = 0;
foreach (Pair p in declarators){
VariableInfo vi = (VariableInfo) p.First;
Expression e = (Expression) p.Second;
+ vi.Number = -1;
+
//
// The rules for the possible declarators are pretty wise,
// but the production on the grammar is more concise.
"No need to use fixed statement for parameters or " +
"local variable declarations (address is already " +
"fixed)");
- continue;
+ return false;
}
e = e.Resolve (ec);
if (e == null)
- continue;
+ return false;
child = ((Unary) e).Expr;
if (!TypeManager.VerifyUnManaged (child.Type, loc))
- continue;
-
- //
- // Store pointer in pinned location
- //
- e.Emit (ec);
- ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
-
- is_ret = statement.Emit (ec);
+ return false;
- // Clear the pinned variable.
- ig.Emit (OpCodes.Ldc_I4_0);
- ig.Emit (OpCodes.Conv_U);
- ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
+ data [i].is_object = true;
+ data [i].expr = e;
+ data [i].converted = null;
+ data [i].vi = vi;
+ i++;
continue;
}
e = e.Resolve (ec);
if (e == null)
- continue;
+ return false;
//
// Case 2: Array
// Provided that array_type is unmanaged,
//
if (!TypeManager.VerifyUnManaged (array_type, loc))
- continue;
+ return false;
//
// and T* is implicitly convertible to the
// pointer type given in the fixed statement.
//
- ArrayPtr array_ptr = new ArrayPtr (e);
+ ArrayPtr array_ptr = new ArrayPtr (e, loc);
Expression converted = Expression.ConvertImplicitRequired (
ec, array_ptr, vi.VariableType, loc);
if (converted == null)
- continue;
+ return false;
+
+ data [i].is_object = false;
+ data [i].expr = e;
+ data [i].converted = converted;
+ data [i].vi = vi;
+ i++;
+
+ continue;
+ }
+
+ //
+ // Case 3: string
+ //
+ if (e.Type == TypeManager.string_type){
+ data [i].is_object = false;
+ data [i].expr = e;
+ data [i].converted = null;
+ data [i].vi = vi;
+ i++;
+ }
+ }
+
+ return statement.Resolve (ec);
+ }
+
+ protected override bool DoEmit (EmitContext ec)
+ {
+ ILGenerator ig = ec.ig;
+
+ bool is_ret = false;
+
+ for (int i = 0; i < data.Length; i++) {
+ VariableInfo vi = data [i].vi;
+ //
+ // Case 1: & object.
+ //
+ if (data [i].is_object) {
//
// Store pointer in pinned location
//
- converted.Emit (ec);
+ data [i].expr.Emit (ec);
+ ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
+
+ is_ret = statement.Emit (ec);
+
+ // Clear the pinned variable.
+ ig.Emit (OpCodes.Ldc_I4_0);
+ ig.Emit (OpCodes.Conv_U);
+ ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
+
+ continue;
+ }
+
+ //
+ // Case 2: Array
+ //
+ if (data [i].expr.Type.IsArray){
+ //
+ // Store pointer in pinned location
+ //
+ data [i].converted.Emit (ec);
ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
//
// Case 3: string
//
- if (e.Type == TypeManager.string_type){
+ if (data [i].expr.Type == TypeManager.string_type){
LocalBuilder pinned_string = ig.DeclareLocal (TypeManager.string_type);
TypeManager.MakePinned (pinned_string);
- e.Emit (ec);
+ data [i].expr.Emit (ec);
ig.Emit (OpCodes.Stloc, pinned_string);
- Expression sptr = new StringPtr (pinned_string);
+ Expression sptr = new StringPtr (pinned_string, loc);
Expression converted = Expression.ConvertImplicitRequired (
ec, sptr, vi.VariableType, loc);
}
public class Catch {
- public readonly string Type;
public readonly string Name;
public readonly Block Block;
public readonly Location Location;
+
+ Expression type_expr;
+ Type type;
- public Catch (string type, string name, Block block, Location l)
+ public Catch (Expression type, string name, Block block, Location l)
{
- Type = type;
+ type_expr = type;
Name = name;
Block = block;
Location = l;
}
+
+ public Type CatchType {
+ get {
+ return type;
+ }
+ }
+
+ public bool IsGeneral {
+ get {
+ return type_expr == null;
+ }
+ }
+
+ public bool Resolve (EmitContext ec)
+ {
+ if (type_expr != null) {
+ type = ec.DeclSpace.ResolveType (type_expr, false, Location);
+ if (type == null)
+ return false;
+
+ if (type != TypeManager.exception_type && !type.IsSubclassOf (TypeManager.exception_type)){
+ Report.Error (155, Location,
+ "The type caught or thrown must be derived " +
+ "from System.Exception");
+ return false;
+ }
+ } else
+ type = null;
+
+ if (!Block.Resolve (ec))
+ return false;
+
+ return true;
+ }
}
public class Try : Statement {
//
// specific, general and fini might all be null.
//
- public Try (Block block, ArrayList specific, Catch general, Block fini)
+ public Try (Block block, ArrayList specific, Catch general, Block fini, Location l)
{
if (specific == null && general == null){
Console.WriteLine ("CIR.Try: Either specific or general have to be non-null");
this.Specific = specific;
this.General = general;
this.Fini = fini;
+ loc = l;
}
public override bool Resolve (EmitContext ec)
{
bool ok = true;
- if (General != null)
- if (!General.Block.Resolve (ec))
- ok = false;
+ ec.StartFlowBranching (FlowBranchingType.EXCEPTION, Block.StartLocation);
+
+ Report.Debug (1, "START OF TRY BLOCK", Block.StartLocation);
+
+ bool old_in_try = ec.InTry;
+ ec.InTry = true;
+
+ if (!Block.Resolve (ec))
+ ok = false;
+
+ ec.InTry = old_in_try;
+
+ FlowBranching.UsageVector vector = ec.CurrentBranching.CurrentUsageVector;
+
+ Report.Debug (1, "START OF CATCH BLOCKS", vector);
foreach (Catch c in Specific){
- if (!c.Block.Resolve (ec))
+ ec.CurrentBranching.CreateSibling ();
+ Report.Debug (1, "STARTED SIBLING FOR CATCH", ec.CurrentBranching);
+
+ if (c.Name != null) {
+ VariableInfo vi = c.Block.GetVariableInfo (c.Name);
+ if (vi == null)
+ throw new Exception ();
+
+ vi.Number = -1;
+ }
+
+ bool old_in_catch = ec.InCatch;
+ ec.InCatch = true;
+
+ if (!c.Resolve (ec))
ok = false;
+
+ ec.InCatch = old_in_catch;
+
+ FlowBranching.UsageVector current = ec.CurrentBranching.CurrentUsageVector;
+
+ if (!current.AlwaysReturns && !current.AlwaysBreaks)
+ vector.AndLocals (current);
}
- if (!Block.Resolve (ec))
- ok = false;
+ Report.Debug (1, "END OF CATCH BLOCKS", ec.CurrentBranching);
+
+ if (General != null){
+ ec.CurrentBranching.CreateSibling ();
+ Report.Debug (1, "STARTED SIBLING FOR GENERAL", ec.CurrentBranching);
+
+ bool old_in_catch = ec.InCatch;
+ ec.InCatch = true;
+
+ if (!General.Resolve (ec))
+ ok = false;
+
+ ec.InCatch = old_in_catch;
+
+ FlowBranching.UsageVector current = ec.CurrentBranching.CurrentUsageVector;
+
+ if (!current.AlwaysReturns && !current.AlwaysBreaks)
+ vector.AndLocals (current);
+ }
+
+ Report.Debug (1, "END OF GENERAL CATCH BLOCKS", ec.CurrentBranching);
+
+ if (Fini != null) {
+ ec.CurrentBranching.CreateSiblingForFinally ();
+ Report.Debug (1, "STARTED SIBLING FOR FINALLY", ec.CurrentBranching, vector);
+
+ bool old_in_finally = ec.InFinally;
+ ec.InFinally = true;
- if (Fini != null)
if (!Fini.Resolve (ec))
ok = false;
-
+
+ ec.InFinally = old_in_finally;
+ }
+
+ FlowReturns returns = ec.EndFlowBranching ();
+
+ FlowBranching.UsageVector f_vector = ec.CurrentBranching.CurrentUsageVector;
+
+ Report.Debug (1, "END OF FINALLY", ec.CurrentBranching, returns, vector, f_vector);
+
+ if ((returns == FlowReturns.SOMETIMES) || (returns == FlowReturns.ALWAYS)) {
+ ec.CurrentBranching.CheckOutParameters (f_vector.Parameters, loc);
+ }
+
+ ec.CurrentBranching.CurrentUsageVector.Or (vector);
+
+ Report.Debug (1, "END OF TRY", ec.CurrentBranching);
+
return ok;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
ILGenerator ig = ec.ig;
Label end;
Label finish = ig.DefineLabel ();;
bool returns;
-
+
+ ec.TryCatchLevel++;
end = ig.BeginExceptionBlock ();
bool old_in_try = ec.InTry;
ec.InTry = true;
DeclSpace ds = ec.DeclSpace;
foreach (Catch c in Specific){
- Type catch_type = RootContext.LookupType (ds, c.Type, false, c.Location);
VariableInfo vi;
- if (catch_type == null)
- return false;
-
- ig.BeginCatchBlock (catch_type);
+ ig.BeginCatchBlock (c.CatchType);
if (c.Name != null){
vi = c.Block.GetVariableInfo (c.Name);
- if (vi == null){
- Console.WriteLine ("This should not happen! variable does not exist in this block");
- Environment.Exit (0);
- }
-
+ if (vi == null)
+ throw new Exception ("Variable does not exist in this block");
+
ig.Emit (OpCodes.Stloc, vi.LocalBuilder);
} else
ig.Emit (OpCodes.Pop);
}
ig.EndExceptionBlock ();
+ ec.TryCatchLevel--;
- //
- // FIXME: Is this correct?
- // Replace with `returns' and check test-18, maybe we can
- // perform an optimization here.
- //
- return returns;
+ if (!returns || ec.InTry || ec.InCatch)
+ return returns;
+
+ // Unfortunately, System.Reflection.Emit automatically emits a leave
+ // to the end of the finally block. This is a problem if `returns'
+ // is true since we may jump to a point after the end of the method.
+ // As a workaround, emit an explicit ret here.
+
+ if (ec.ReturnType != null)
+ ec.ig.Emit (OpCodes.Ldloc, ec.TemporaryReturn ());
+ ec.ig.Emit (OpCodes.Ret);
+
+ return true;
}
}
- //
- // FIXME: We still do not support the expression variant of the using
- // statement.
- //
public class Using : Statement {
object expression_or_block;
Statement Statement;
+ ArrayList var_list;
+ Expression expr;
+ Type expr_type;
+ Expression conv;
+ Expression [] converted_vars;
+ ExpressionStatement [] assign;
public Using (object expression_or_block, Statement stmt, Location l)
{
}
//
- // Emits the code for the case of using using a local variable declaration.
+ // Resolves for the case of using using a local variable declaration.
//
- bool EmitLocalVariableDecls (EmitContext ec, string type_name, ArrayList var_list)
+ bool ResolveLocalVariableDecls (EmitContext ec)
{
- ILGenerator ig = ec.ig;
- Expression [] converted_vars;
bool need_conv = false;
- Type type = RootContext.LookupType (ec.DeclSpace, type_name, false, loc);
+ expr_type = ec.DeclSpace.ResolveType (expr, false, loc);
int i = 0;
- if (type == null)
+ if (expr_type == null)
return false;
-
+
//
// The type must be an IDisposable or an implicit conversion
// must exist.
//
converted_vars = new Expression [var_list.Count];
- if (!TypeManager.ImplementsInterface (type, TypeManager.idisposable_type)){
+ assign = new ExpressionStatement [var_list.Count];
+ if (!TypeManager.ImplementsInterface (expr_type, TypeManager.idisposable_type)){
foreach (DictionaryEntry e in var_list){
Expression var = (Expression) e.Key;
- var = var.Resolve (ec);
+ var = var.ResolveLValue (ec, new EmptyExpression ());
if (var == null)
return false;
- converted_vars [i] = Expression.ConvertImplicit (
+ converted_vars [i] = Expression.ConvertImplicitRequired (
ec, var, TypeManager.idisposable_type, loc);
if (converted_vars [i] == null)
}
need_conv = true;
}
-
+
i = 0;
- bool old_in_try = ec.InTry;
- ec.InTry = true;
- bool error = false;
foreach (DictionaryEntry e in var_list){
LocalVariableReference var = (LocalVariableReference) e.Key;
- Expression expr = (Expression) e.Value;
+ Expression new_expr = (Expression) e.Value;
Expression a;
- a = new Assign (var, expr, loc);
+ a = new Assign (var, new_expr, loc);
a = a.Resolve (ec);
+ if (a == null)
+ return false;
+
if (!need_conv)
converted_vars [i] = var;
+ assign [i] = (ExpressionStatement) a;
i++;
- if (a == null){
- error = true;
- continue;
- }
- ((ExpressionStatement) a).EmitStatement (ec);
+ }
+
+ return true;
+ }
+
+ bool ResolveExpression (EmitContext ec)
+ {
+ if (!TypeManager.ImplementsInterface (expr_type, TypeManager.idisposable_type)){
+ conv = Expression.ConvertImplicitRequired (
+ ec, expr, TypeManager.idisposable_type, loc);
+
+ if (conv == null)
+ return false;
+ }
+
+ return true;
+ }
+
+ //
+ // Emits the code for the case of using using a local variable declaration.
+ //
+ bool EmitLocalVariableDecls (EmitContext ec)
+ {
+ ILGenerator ig = ec.ig;
+ int i = 0;
+
+ bool old_in_try = ec.InTry;
+ ec.InTry = true;
+ for (i = 0; i < assign.Length; i++) {
+ assign [i].EmitStatement (ec);
ig.BeginExceptionBlock ();
-
}
- if (error)
- return false;
Statement.Emit (ec);
ec.InTry = old_in_try;
return false;
}
- bool EmitExpression (EmitContext ec, Expression expr)
+ bool EmitExpression (EmitContext ec)
{
- Type expr_type = expr.Type;
- Expression conv = null;
-
- if (!TypeManager.ImplementsInterface (expr_type, TypeManager.idisposable_type)){
- conv = Expression.ConvertImplicit (
- ec, expr, TypeManager.idisposable_type, loc);
-
- if (conv == null)
- return false;
- }
-
//
// Make a copy of the expression and operate on that.
//
}
public override bool Resolve (EmitContext ec)
- {
- return Statement.Resolve (ec);
- }
-
- public override bool Emit (EmitContext ec)
{
if (expression_or_block is DictionaryEntry){
- string t = (string) ((DictionaryEntry) expression_or_block).Key;
- ArrayList var_list = (ArrayList)((DictionaryEntry)expression_or_block).Value;
+ expr = (Expression) ((DictionaryEntry) expression_or_block).Key;
+ var_list = (ArrayList)((DictionaryEntry)expression_or_block).Value;
- return EmitLocalVariableDecls (ec, t, var_list);
- } if (expression_or_block is Expression){
- Expression e = (Expression) expression_or_block;
+ if (!ResolveLocalVariableDecls (ec))
+ return false;
- e = e.Resolve (ec);
- if (e == null)
+ } else if (expression_or_block is Expression){
+ expr = (Expression) expression_or_block;
+
+ expr = expr.Resolve (ec);
+ if (expr == null)
return false;
- return EmitExpression (ec, e);
- }
+ expr_type = expr.Type;
+
+ if (!ResolveExpression (ec))
+ return false;
+ }
+
+ return Statement.Resolve (ec);
+ }
+
+ protected override bool DoEmit (EmitContext ec)
+ {
+ if (expression_or_block is DictionaryEntry)
+ return EmitLocalVariableDecls (ec);
+ else if (expression_or_block is Expression)
+ return EmitExpression (ec);
+
return false;
}
}
/// Implementation of the foreach C# statement
/// </summary>
public class Foreach : Statement {
- string type;
+ Expression type;
LocalVariableReference variable;
Expression expr;
Statement statement;
+ ForeachHelperMethods hm;
+ Expression empty, conv;
+ Type array_type, element_type;
+ Type var_type;
- public Foreach (string type, LocalVariableReference var, Expression expr,
+ public Foreach (Expression type, LocalVariableReference var, Expression expr,
Statement stmt, Location l)
{
this.type = type;
public override bool Resolve (EmitContext ec)
{
expr = expr.Resolve (ec);
- return statement.Resolve (ec) && expr != null;
+ if (expr == null)
+ return false;
+
+ var_type = ec.DeclSpace.ResolveType (type, false, loc);
+ if (var_type == null)
+ return false;
+
+ //
+ // We need an instance variable. Not sure this is the best
+ // way of doing this.
+ //
+ // FIXME: When we implement propertyaccess, will those turn
+ // out to return values in ExprClass? I think they should.
+ //
+ if (!(expr.eclass == ExprClass.Variable || expr.eclass == ExprClass.Value ||
+ expr.eclass == ExprClass.PropertyAccess || expr.eclass == ExprClass.IndexerAccess)){
+ error1579 (expr.Type);
+ return false;
+ }
+
+ if (expr.Type.IsArray) {
+ array_type = expr.Type;
+ element_type = array_type.GetElementType ();
+
+ empty = new EmptyExpression (element_type);
+ } else {
+ hm = ProbeCollectionType (ec, expr.Type);
+ if (hm == null){
+ error1579 (expr.Type);
+ return false;
+ }
+
+ array_type = expr.Type;
+ element_type = hm.element_type;
+
+ empty = new EmptyExpression (hm.element_type);
+ }
+
+ ec.StartFlowBranching (FlowBranchingType.LOOP_BLOCK, loc);
+ ec.CurrentBranching.CreateSibling ();
+
+ //
+ //
+ // FIXME: maybe we can apply the same trick we do in the
+ // array handling to avoid creating empty and conv in some cases.
+ //
+ // Although it is not as important in this case, as the type
+ // will not likely be object (what the enumerator will return).
+ //
+ conv = Expression.ConvertExplicit (ec, empty, var_type, loc);
+ if (conv == null)
+ return false;
+
+ if (variable.ResolveLValue (ec, empty) == null)
+ return false;
+
+ if (!statement.Resolve (ec))
+ return false;
+
+ FlowReturns returns = ec.EndFlowBranching ();
+
+ return true;
}
//
//
static MethodInfo FetchMethodMoveNext (Type t)
{
- MemberInfo [] move_next_list;
+ MemberList move_next_list;
move_next_list = TypeContainer.FindMembers (
t, MemberTypes.Method,
BindingFlags.Public | BindingFlags.Instance,
Type.FilterName, "MoveNext");
- if (move_next_list == null || move_next_list.Length == 0)
+ if (move_next_list.Count == 0)
return null;
foreach (MemberInfo m in move_next_list){
//
static MethodInfo FetchMethodGetCurrent (Type t)
{
- MemberInfo [] move_next_list;
+ MemberList move_next_list;
move_next_list = TypeContainer.FindMembers (
t, MemberTypes.Method,
BindingFlags.Public | BindingFlags.Instance,
Type.FilterName, "get_Current");
- if (move_next_list == null || move_next_list.Length == 0)
+ if (move_next_list.Count == 0)
return null;
foreach (MemberInfo m in move_next_list){
MethodInfo mi = (MethodInfo) m;
Type [] args;
-
+
args = TypeManager.GetArgumentTypes (mi);
if (args != null && args.Length == 0)
return mi;
public MethodInfo get_enumerator;
public MethodInfo move_next;
public MethodInfo get_current;
+ public Type element_type;
+ public Type enumerator_type;
+ public bool is_disposable;
public ForeachHelperMethods (EmitContext ec)
{
this.ec = ec;
+ this.element_type = TypeManager.object_type;
+ this.enumerator_type = TypeManager.ienumerator_type;
+ this.is_disposable = true;
}
}
}
ForeachHelperMethods hm = (ForeachHelperMethods) criteria;
EmitContext ec = hm.ec;
-
+
//
// Check whether GetEnumerator is accessible to us
//
// Ok, we can access it, now make sure that we can do something
// with this `GetEnumerator'
//
- if (mi.ReturnType == TypeManager.ienumerator_type ||
- TypeManager.ienumerator_type.IsAssignableFrom (mi.ReturnType)){
+
+ if (mi.ReturnType == TypeManager.ienumerator_type ||
+ TypeManager.ienumerator_type.IsAssignableFrom (mi.ReturnType) ||
+ (!RootContext.StdLib && TypeManager.ImplementsInterface (mi.ReturnType, TypeManager.ienumerator_type))) {
hm.move_next = TypeManager.bool_movenext_void;
hm.get_current = TypeManager.object_getcurrent_void;
return true;
if (hm.get_current == null)
return false;
+ hm.element_type = hm.get_current.ReturnType;
+ hm.enumerator_type = return_type;
+ hm.is_disposable = TypeManager.ImplementsInterface (
+ hm.enumerator_type, TypeManager.idisposable_type);
+
return true;
}
static bool TryType (Type t, ForeachHelperMethods hm)
{
- MemberInfo [] mi;
+ MemberList mi;
mi = TypeContainer.FindMembers (t, MemberTypes.Method,
BindingFlags.Public | BindingFlags.NonPublic |
BindingFlags.Instance,
FilterEnumerator, hm);
- if (mi == null || mi.Length == 0)
+ if (mi.Count == 0)
return false;
hm.get_enumerator = (MethodInfo) mi [0];
// FIXME: possible optimization.
// We might be able to avoid creating `empty' if the type is the sam
//
- bool EmitCollectionForeach (EmitContext ec, Type var_type, ForeachHelperMethods hm)
+ bool EmitCollectionForeach (EmitContext ec)
{
ILGenerator ig = ec.ig;
LocalBuilder enumerator, disposable;
- Expression empty = new EmptyExpression ();
- Expression conv;
- //
- // FIXME: maybe we can apply the same trick we do in the
- // array handling to avoid creating empty and conv in some cases.
- //
- // Although it is not as important in this case, as the type
- // will not likely be object (what the enumerator will return).
- //
- conv = Expression.ConvertExplicit (ec, empty, var_type, loc);
- if (conv == null)
- return false;
-
- enumerator = ig.DeclareLocal (TypeManager.ienumerator_type);
- disposable = ig.DeclareLocal (TypeManager.idisposable_type);
+ enumerator = ig.DeclareLocal (hm.enumerator_type);
+ if (hm.is_disposable)
+ disposable = ig.DeclareLocal (TypeManager.idisposable_type);
+ else
+ disposable = null;
//
// Instantiate the enumerator
// Protect the code in a try/finalize block, so that
// if the beast implement IDisposable, we get rid of it
//
- Label l = ig.BeginExceptionBlock ();
+ Label l;
bool old_in_try = ec.InTry;
- ec.InTry = true;
+
+ if (hm.is_disposable) {
+ l = ig.BeginExceptionBlock ();
+ ec.InTry = true;
+ }
Label end_try = ig.DefineLabel ();
//
// Now the finally block
//
- Label end_finally = ig.DefineLabel ();
- bool old_in_finally = ec.InFinally;
- ec.InFinally = true;
- ig.BeginFinallyBlock ();
+ if (hm.is_disposable) {
+ Label end_finally = ig.DefineLabel ();
+ bool old_in_finally = ec.InFinally;
+ ec.InFinally = true;
+ ig.BeginFinallyBlock ();
- ig.Emit (OpCodes.Ldloc, enumerator);
- ig.Emit (OpCodes.Isinst, TypeManager.idisposable_type);
- ig.Emit (OpCodes.Stloc, disposable);
- ig.Emit (OpCodes.Ldloc, disposable);
- ig.Emit (OpCodes.Brfalse, end_finally);
- ig.Emit (OpCodes.Ldloc, disposable);
- ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
- ig.MarkLabel (end_finally);
- ec.InFinally = old_in_finally;
+ ig.Emit (OpCodes.Ldloc, enumerator);
+ ig.Emit (OpCodes.Isinst, TypeManager.idisposable_type);
+ ig.Emit (OpCodes.Stloc, disposable);
+ ig.Emit (OpCodes.Ldloc, disposable);
+ ig.Emit (OpCodes.Brfalse, end_finally);
+ ig.Emit (OpCodes.Ldloc, disposable);
+ ig.Emit (OpCodes.Callvirt, TypeManager.void_dispose_void);
+ ig.MarkLabel (end_finally);
+ ec.InFinally = old_in_finally;
- // The runtime generates this anyways.
- // ig.Emit (OpCodes.Endfinally);
+ // The runtime generates this anyways.
+ // ig.Emit (OpCodes.Endfinally);
- ig.EndExceptionBlock ();
+ ig.EndExceptionBlock ();
+ }
ig.MarkLabel (ec.LoopEnd);
return false;
// FIXME: possible optimization.
// We might be able to avoid creating `empty' if the type is the sam
//
- bool EmitArrayForeach (EmitContext ec, Type var_type)
+ bool EmitArrayForeach (EmitContext ec)
{
- Type array_type = expr.Type;
- Type element_type = array_type.GetElementType ();
- Expression conv = null;
- Expression empty = new EmptyExpression (element_type);
-
- conv = Expression.ConvertExplicit (ec, empty, var_type, loc);
- if (conv == null)
- return false;
-
int rank = array_type.GetArrayRank ();
ILGenerator ig = ec.ig;
return false;
}
- public override bool Emit (EmitContext ec)
+ protected override bool DoEmit (EmitContext ec)
{
- Type var_type;
bool ret_val;
- var_type = RootContext.LookupType (ec.DeclSpace, type, false, loc);
- if (var_type == null)
- return false;
-
- //
- // We need an instance variable. Not sure this is the best
- // way of doing this.
- //
- // FIXME: When we implement propertyaccess, will those turn
- // out to return values in ExprClass? I think they should.
- //
- if (!(expr.eclass == ExprClass.Variable || expr.eclass == ExprClass.Value ||
- expr.eclass == ExprClass.PropertyAccess)){
- error1579 (expr.Type);
- return false;
- }
-
ILGenerator ig = ec.ig;
Label old_begin = ec.LoopBegin, old_end = ec.LoopEnd;
bool old_inloop = ec.InLoop;
+ int old_loop_begin_try_catch_level = ec.LoopBeginTryCatchLevel;
ec.LoopBegin = ig.DefineLabel ();
ec.LoopEnd = ig.DefineLabel ();
ec.InLoop = true;
+ ec.LoopBeginTryCatchLevel = ec.TryCatchLevel;
- if (expr.Type.IsArray)
- ret_val = EmitArrayForeach (ec, var_type);
- else {
- ForeachHelperMethods hm;
-
- hm = ProbeCollectionType (ec, expr.Type);
- if (hm == null){
- error1579 (expr.Type);
- return false;
- }
-
- ret_val = EmitCollectionForeach (ec, var_type, hm);
- }
+ if (hm != null)
+ ret_val = EmitCollectionForeach (ec);
+ else
+ ret_val = EmitArrayForeach (ec);
ec.LoopBegin = old_begin;
ec.LoopEnd = old_end;
ec.InLoop = old_inloop;
+ ec.LoopBeginTryCatchLevel = old_loop_begin_try_catch_level;
return ret_val;
}
}
}
-
projects / mono.git / blobdiff