//
// Author:
// Martin Baulig (martin@ximian.com)
+// Raja R Harinath (rharinath@novell.com)
//
// (C) 2001, 2002, 2003 Ximian, Inc.
//
namespace Mono.CSharp
{
- public enum TriState : byte {
- // Never < Sometimes < Always
- Never,
- Sometimes,
- Always
- }
-
// <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.
Finally
}
- public sealed class Reachability
- {
- TriState returns, throws, barrier;
-
- public TriState Returns {
- get { return returns; }
- }
- public TriState Throws {
- get { return throws; }
- }
- public TriState Barrier {
- get { return barrier; }
- }
-
- Reachability (TriState returns, TriState throws, TriState barrier)
- {
- this.returns = returns;
- this.throws = throws;
- this.barrier = barrier;
- }
-
- public Reachability Clone ()
- {
- return new Reachability (returns, throws, barrier);
- }
-
- public static TriState TriState_Meet (TriState a, TriState b)
- {
- // (1) if both are Never, return Never
- // (2) if both are Always, return Always
- // (3) otherwise, return Sometimes
- // note that (3) => (3') if both are Sometimes, return Sometimes
- return a == b ? a : TriState.Sometimes;
- }
-
- public static TriState TriState_Max (TriState a, TriState b)
- {
- return ((byte) a > (byte) b) ? a : b;
- }
-
- public void Meet (Reachability b)
- {
- if ((AlwaysReturns && b.AlwaysHasBarrier) || (AlwaysHasBarrier && b.AlwaysReturns))
- returns = TriState.Always;
- else
- returns = TriState_Meet (returns, b.returns);
-
- throws = TriState_Meet (throws, b.throws);
- barrier = TriState_Meet (barrier, b.barrier);
- }
-
- public void Or (Reachability b)
- {
- returns = TriState_Max (returns, b.returns);
- throws = TriState_Max (throws, b.throws);
- barrier = TriState_Max (barrier, b.barrier);
- }
-
- public static Reachability Always ()
- {
- return new Reachability (TriState.Never, TriState.Never, TriState.Never);
- }
-
- TriState Unreachable {
- get { return TriState_Max (returns, TriState_Max (throws, barrier)); }
- }
-
- TriState Reachable {
- get {
- TriState unreachable = Unreachable;
- if (unreachable == TriState.Sometimes)
- return TriState.Sometimes;
- return unreachable == TriState.Always ? TriState.Never : TriState.Always;
- }
- }
-
- public bool AlwaysReturns {
- get { return returns == TriState.Always; }
- }
-
- public bool AlwaysThrows {
- get { return throws == TriState.Always; }
- }
-
- public bool AlwaysHasBarrier {
- get { return barrier == TriState.Always; }
- }
-
- public bool IsUnreachable {
- get { return Unreachable == TriState.Always; }
- }
-
- public void SetReturns ()
- {
- returns = TriState.Always;
- }
-
- public void SetThrows ()
- {
- throws = TriState.Always;
- }
-
- public void SetBarrier ()
- {
- barrier = TriState.Always;
- }
-
- static string ShortName (TriState returns)
- {
- switch (returns) {
- case TriState.Never:
- return "N";
- case TriState.Sometimes:
- return "S";
- default:
- return "A";
- }
- }
-
- public override string ToString ()
- {
- return String.Format ("[{0}:{1}:{2}:{3}]",
- ShortName (returns), ShortName (throws), ShortName (barrier),
- ShortName (Reachable));
- }
- }
-
public static FlowBranching CreateBranching (FlowBranching parent, BranchingType type, Block block, Location loc)
{
switch (type) {
// </summary>
public readonly Block Block;
- // <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>
// Private.
//
MyBitVector locals, parameters;
- Reachability reachability;
+ bool is_unreachable;
static int next_id = 0;
int id;
? MyBitVector.Empty
: new MyBitVector (parent == null ? MyBitVector.Empty : parent.parameters, num_params);
- reachability = parent == null ? Reachability.Always () : parent.Reachability.Clone ();
+ if (parent != null)
+ is_unreachable = parent.is_unreachable;
id = ++next_id;
+
}
public UsageVector (SiblingType type, UsageVector parent, Block block, Location loc)
: this (type, parent, block, loc, parent.CountParameters, parent.CountLocals)
{ }
- public UsageVector (MyBitVector parameters, MyBitVector locals, Reachability reachability, Block block, Location loc)
+ private UsageVector (MyBitVector parameters, MyBitVector locals, bool is_unreachable, Block block, Location loc)
{
this.Type = SiblingType.Block;
this.Location = loc;
this.Block = block;
- this.reachability = reachability;
+ this.is_unreachable = is_unreachable;
+
this.parameters = parameters;
this.locals = locals;
id = ++next_id;
+
}
// <summary>
retval.locals = locals.Clone ();
retval.parameters = parameters.Clone ();
- retval.reachability = reachability.Clone ();
+ retval.is_unreachable = is_unreachable;
return retval;
}
public bool IsAssigned (VariableInfo var, bool ignoreReachability)
{
- if (!ignoreReachability && !var.IsParameter && Reachability.IsUnreachable)
+ if (!ignoreReachability && !var.IsParameter && IsUnreachable)
return true;
return var.IsAssigned (var.IsParameter ? parameters : locals);
public void SetAssigned (VariableInfo var)
{
- if (!var.IsParameter && Reachability.IsUnreachable)
+ if (!var.IsParameter && IsUnreachable)
return;
- IsDirty = true;
var.SetAssigned (var.IsParameter ? parameters : locals);
}
public bool IsFieldAssigned (VariableInfo var, string name)
{
- if (!var.IsParameter && Reachability.IsUnreachable)
+ if (!var.IsParameter && IsUnreachable)
return true;
return var.IsFieldAssigned (var.IsParameter ? parameters : locals, name);
public void SetFieldAssigned (VariableInfo var, string name)
{
- if (!var.IsParameter && Reachability.IsUnreachable)
+ if (!var.IsParameter && IsUnreachable)
return;
- IsDirty = true;
var.SetFieldAssigned (var.IsParameter ? parameters : locals, name);
}
- public Reachability Reachability {
- get { return reachability; }
+ public bool IsUnreachable {
+ get { return is_unreachable; }
}
- public void Return ()
+ public void ResetBarrier ()
{
- if (!reachability.IsUnreachable) {
- IsDirty = true;
- reachability.SetReturns ();
- }
+ is_unreachable = false;
}
- public void Throw ()
+ public void Goto ()
{
- if (!reachability.IsUnreachable) {
- IsDirty = true;
- reachability.SetThrows ();
- reachability.SetBarrier ();
- }
+ is_unreachable = true;
}
- public void Goto ()
+ public static UsageVector MergeSiblings (UsageVector sibling_list, Location loc)
{
- if (!reachability.IsUnreachable) {
- IsDirty = true;
- reachability.SetBarrier ();
+ if (sibling_list.Next == null)
+ return sibling_list;
+
+ MyBitVector locals = null;
+ MyBitVector parameters = null;
+ bool is_unreachable = sibling_list.is_unreachable;
+
+ if (!sibling_list.IsUnreachable) {
+ locals &= sibling_list.locals;
+ parameters &= sibling_list.parameters;
+ }
+
+ for (UsageVector child = sibling_list.Next; child != null; child = child.Next) {
+ is_unreachable &= child.is_unreachable;
+
+ if (!child.IsUnreachable) {
+ locals &= child.locals;
+ parameters &= child.parameters;
+ }
}
+
+ return new UsageVector (parameters, locals, is_unreachable, null, loc);
}
// <summary>
// Merges a child branching.
// </summary>
- public UsageVector MergeChild (UsageVector child, bool implicit_block)
+ public UsageVector MergeChild (UsageVector child, bool overwrite)
{
- Report.Debug (2, " MERGING CHILD EFFECTS", this, child, IsDirty, reachability, Type);
+ Report.Debug (2, " MERGING CHILD EFFECTS", this, child, Type);
- Reachability new_r = child.Reachability;
+ bool new_isunr = child.is_unreachable;
//
// We've now either reached the point after the branching or we will
// we need to look at (see above).
//
- if ((Type == SiblingType.SwitchSection) && !new_r.IsUnreachable) {
+ if ((Type == SiblingType.SwitchSection) && !new_isunr) {
Report.Error (163, Location,
"Control cannot fall through from one " +
"case label to another");
return child;
}
- MyBitVector.Or (ref locals, child.LocalVector);
- MyBitVector.Or (ref parameters, child.ParameterVector);
+ locals |= child.locals;
+ parameters |= child.parameters;
- if (implicit_block)
- reachability = new_r.Clone ();
+ if (overwrite)
+ is_unreachable = new_isunr;
else
- reachability.Or (new_r);
-
- IsDirty = true;
+ is_unreachable |= new_isunr;
return child;
}
- // <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 (UsageVector o_vectors)
- {
- Report.Debug (1, " MERGING JUMP ORIGINS", this);
-
- if (o_vectors == null)
- return;
-
- UsageVector vector = o_vectors;
- if (reachability.IsUnreachable) {
- Report.Debug (1, " MERGING JUMP ORIGIN INTO UNREACHABLE", this, vector);
- MyBitVector.Or (ref locals, vector.locals);
- MyBitVector.Or (ref parameters, vector.parameters);
- reachability.Meet (vector.Reachability);
- vector = vector.Next;
- }
-
- for (; vector != null; vector = vector.Next) {
- Report.Debug (1, " MERGING JUMP ORIGIN", this, vector);
- MyBitVector.And (ref locals, vector.locals);
- MyBitVector.And (ref parameters, vector.parameters);
- reachability.Meet (vector.Reachability);
-
- Report.Debug (1, " MERGING JUMP ORIGIN #1", vector);
- }
-
- Report.Debug (1, " MERGING JUMP ORIGINS DONE", this);
- }
-
public void MergeOrigins (UsageVector o_vectors)
{
Report.Debug (1, " MERGING BREAK ORIGINS", this);
if (o_vectors == null)
return;
- UsageVector vector = o_vectors;
-
- if (reachability.IsUnreachable) {
- Report.Debug (1, " MERGING BREAK ORIGIN INTO UNREACHABLE", vector);
- locals = vector.Locals;
- parameters = vector.Parameters;
- reachability.Meet (vector.Reachability);
- vector = vector.Next;
+ if (IsUnreachable) {
+ if (locals != null)
+ locals.SetAll (true);
+ if (parameters != null)
+ parameters.SetAll (true);
}
- for (; vector != null; vector = vector.Next) {
+ for (UsageVector vector = o_vectors; vector != null; vector = vector.Next) {
Report.Debug (1, " MERGING BREAK ORIGIN", vector);
- MyBitVector.And (ref locals, vector.locals);
- MyBitVector.And (ref parameters, vector.parameters);
- reachability.Meet (vector.Reachability);
+ if (vector.IsUnreachable)
+ continue;
+ locals &= vector.locals;
+ parameters &= vector.parameters;
+ is_unreachable &= vector.is_unreachable;
}
Report.Debug (1, " MERGING BREAK ORIGINS DONE", this);
}
- // <summary>
- // Returns a deep copy of the parameters.
- // </summary>
- public MyBitVector Parameters {
- get { return parameters == null ? null : parameters.Clone (); }
- }
-
- // <summary>
- // Returns a deep copy of the locals.
- // </summary>
- public MyBitVector Locals {
- get { return locals == null ? null : locals.Clone (); }
- }
-
- public MyBitVector ParameterVector {
- get { return parameters; }
- }
-
- public MyBitVector LocalVector {
- get { return locals; }
- }
-
//
// Debugging stuff.
//
public override string ToString ()
{
- StringBuilder sb = new StringBuilder ();
-
- sb.Append ("Vector (");
- sb.Append (Type);
- sb.Append (",");
- sb.Append (id);
- sb.Append (",");
- sb.Append (IsDirty);
- sb.Append (",");
- sb.Append (reachability);
- if (parameters != null) {
- sb.Append (" - ");
- sb.Append (parameters);
- }
- sb.Append (" - ");
- sb.Append (locals);
- sb.Append (")");
-
- return sb.ToString ();
+ return String.Format ("Vector ({0},{1},{2}-{3}-{4})", Type, id, is_unreachable, parameters, locals);
}
}
protected abstract void AddSibling (UsageVector uv);
- public virtual LabeledStatement LookupLabel (string name, Location loc)
- {
- if (Parent != null)
- return Parent.LookupLabel (name, loc);
-
- Report.Error (
- 159, loc,
- "No such label `" + name + "' in this scope");
- return null;
- }
-
- public abstract void Label (UsageVector origin_vectors);
-
- protected UsageVector Merge (UsageVector sibling_list)
- {
- if (sibling_list.Next == null)
- return sibling_list;
-
- MyBitVector locals = null;
- MyBitVector parameters = null;
-
- Reachability reachability = null;
-
- Report.Debug (2, " MERGING SIBLINGS", this, Name);
-
- for (UsageVector child = sibling_list; child != null; child = child.Next) {
- Report.Debug (2, " MERGING SIBLING ", reachability, child);
-
- if (reachability == null)
- reachability = child.Reachability.Clone ();
- else
- reachability.Meet (child.Reachability);
-
- // 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.
- //
- bool unreachable = child.Reachability.IsUnreachable;
-
- Report.Debug (2, " MERGING SIBLING #1", reachability,
- Type, child.Type, child.Reachability.IsUnreachable, unreachable);
-
- if (!unreachable)
- MyBitVector.And (ref locals, child.LocalVector);
-
- // An `out' parameter must be assigned in all branches which do
- // not always throw an exception.
- if (!child.Reachability.AlwaysThrows)
- MyBitVector.And (ref parameters, child.ParameterVector);
-
- Report.Debug (2, " MERGING SIBLING #2", parameters, locals);
- }
-
- if (reachability == null)
- throw new InternalErrorException ("Cannot happen: the loop above runs at least twice");
-
- Report.Debug (2, " MERGING SIBLINGS DONE", parameters, locals, reachability);
-
- return new UsageVector (parameters, locals, reachability, null, Location);
- }
-
protected abstract UsageVector Merge ();
// <summary>
// </summary>
public UsageVector MergeChild (FlowBranching child)
{
- bool implicit_block = child.Type == BranchingType.Block && child.Block.Implicit;
+ bool overwrite = child.Type == BranchingType.Labeled ||
+ (child.Type == BranchingType.Block && child.Block.Implicit);
Report.Debug (2, " MERGING CHILD", this, child);
- UsageVector result = CurrentUsageVector.MergeChild (child.Merge (), implicit_block);
+ UsageVector result = CurrentUsageVector.MergeChild (child.Merge (), overwrite);
Report.Debug (2, " MERGING CHILD DONE", this, result);
return result;
}
return Parent.AddReturnOrigin (vector, loc);
}
+ // returns true if we crossed an unwind-protected region (try/catch/finally, lock, using, ...)
+ public virtual bool AddGotoOrigin (UsageVector vector, Goto goto_stmt)
+ {
+ return Parent.AddGotoOrigin (vector, goto_stmt);
+ }
+
public virtual void StealFinallyClauses (ref ArrayList list)
{
Parent.StealFinallyClauses (ref list);
sibling_list = sibling;
}
- public override LabeledStatement LookupLabel (string name, Location loc)
- {
- if (Block == null)
- return base.LookupLabel (name, loc);
-
- LabeledStatement s = Block.LookupLabel (name);
- if (s != null)
- return s;
-
- return base.LookupLabel (name, loc);
- }
-
- public override void Label (UsageVector origin_vectors)
+ public override bool AddGotoOrigin (UsageVector vector, Goto goto_stmt)
{
- if (!CurrentUsageVector.Reachability.IsUnreachable) {
- UsageVector vector = CurrentUsageVector.Clone ();
- vector.Next = origin_vectors;
- origin_vectors = vector;
- }
+ LabeledStatement stmt = Block == null ? null : Block.LookupLabel (goto_stmt.Target);
+ if (stmt == null)
+ return Parent.AddGotoOrigin (vector, goto_stmt);
- CurrentUsageVector.MergeJumpOrigins (origin_vectors);
+ // forward jump
+ goto_stmt.SetResolvedTarget (stmt);
+ stmt.AddUsageVector (vector);
+ return false;
}
protected override UsageVector Merge ()
{
- return Merge (sibling_list);
+ Report.Debug (2, " MERGING SIBLINGS", Name);
+ UsageVector vector = UsageVector.MergeSiblings (sibling_list, Location);
+ Report.Debug (2, " MERGING SIBLINGS DONE", Name, vector);
+ return vector;
}
}
public class FlowBranchingLabeled : FlowBranchingBlock
{
LabeledStatement stmt;
+ UsageVector actual;
+
public FlowBranchingLabeled (FlowBranching parent, LabeledStatement stmt)
: base (parent, BranchingType.Labeled, SiblingType.Conditional, null, stmt.loc)
{
this.stmt = stmt;
+ CurrentUsageVector.MergeOrigins (stmt.JumpOrigins);
+ actual = CurrentUsageVector.Clone ();
+
+ // stand-in for backward jumps
+ CurrentUsageVector.ResetBarrier ();
+ }
+
+ public override bool AddGotoOrigin (UsageVector vector, Goto goto_stmt)
+ {
+ if (goto_stmt.Target != stmt.Name)
+ return Parent.AddGotoOrigin (vector, goto_stmt);
+
+ // backward jump
+ goto_stmt.SetResolvedTarget (stmt);
+ actual.MergeOrigins (vector.Clone ());
+
+ return false;
+ }
+
+ protected override UsageVector Merge ()
+ {
+ UsageVector vector = base.Merge ();
+
+ if (actual.IsUnreachable)
+ Report.Warning (162, 2, stmt.loc, "Unreachable code detected");
+
+ actual.MergeChild (vector, false);
+ return actual;
}
}
public class FlowBranchingToplevel : FlowBranchingBlock
{
+ UsageVector return_origins;
+
public FlowBranchingToplevel (FlowBranching parent, ToplevelBlock stmt)
: base (parent, BranchingType.Toplevel, SiblingType.Conditional, stmt, stmt.loc)
{
// <summary>
// Check whether all `out' parameters have been assigned.
// </summary>
- void CheckOutParameters (MyBitVector parameters, Location loc)
+ void CheckOutParameters (UsageVector vector, Location loc)
{
- if (parameters == null)
+ if (vector.IsUnreachable)
return;
-
for (int i = 0; i < param_map.Count; i++) {
VariableInfo var = param_map [i];
if (var == null)
continue;
- if (var.IsAssigned (parameters))
+ if (vector.IsAssigned (var, false))
continue;
Report.Error (177, loc, "The out parameter `{0}' must be assigned to before control leaves the current method",
public override bool AddReturnOrigin (UsageVector vector, Location loc)
{
- CheckOutParameters (vector.Parameters, loc);
+ vector = vector.Clone ();
+ vector.Location = loc;
+ vector.Next = return_origins;
+ return_origins = vector;
return false;
}
// nothing to do
}
- public Reachability End ()
+ public override bool AddGotoOrigin (UsageVector vector, Goto goto_stmt)
{
- UsageVector result = Merge ();
+ string name = goto_stmt.Target;
+ LabeledStatement s = Block.LookupLabel (name);
+ if (s != null)
+ throw new InternalErrorException ("Shouldn't get here");
+
+ if (Parent == null) {
+ Report.Error (159, goto_stmt.loc, "No such label `{0}' in this scope", name);
+ return false;
+ }
- Report.Debug (4, "MERGE TOP BLOCK", Location, result);
+ int errors = Report.Errors;
+ Parent.AddGotoOrigin (vector, goto_stmt);
+ if (errors == Report.Errors)
+ Report.Error (1632, goto_stmt.loc, "Control cannot leave the body of an anonymous method");
+ return false;
+ }
- if (!result.Reachability.AlwaysThrows && !result.Reachability.AlwaysHasBarrier)
- CheckOutParameters (result.Parameters, Location);
+ protected override UsageVector Merge ()
+ {
+ for (UsageVector origin = return_origins; origin != null; origin = origin.Next)
+ CheckOutParameters (origin, origin.Location);
- return result.Reachability;
+ UsageVector vector = base.Merge ();
+ CheckOutParameters (vector, Block.loc);
+ // Note: we _do_not_ merge in the return origins
+ return vector;
+ }
+
+ public bool End ()
+ {
+ return Merge ().IsUnreachable;
}
}
UsageVector break_origins;
UsageVector continue_origins;
UsageVector return_origins;
+ GotoOrigin goto_origins;
+
+ class GotoOrigin {
+ public GotoOrigin Next;
+ public Goto GotoStmt;
+ public UsageVector Vector;
+
+ public GotoOrigin (UsageVector vector, Goto goto_stmt, GotoOrigin next)
+ {
+ Vector = vector;
+ GotoStmt = goto_stmt;
+ Next = next;
+ }
+ }
bool emit_finally;
public override bool AddBreakOrigin (UsageVector vector, Location loc)
{
+ vector = vector.Clone ();
if (finally_vector != null) {
- Report.Error (157, loc, "Control cannot leave the body of a finally clause");
+ vector.MergeChild (finally_vector, false);
+ int errors = Report.Errors;
+ Parent.AddBreakOrigin (vector, loc);
+ if (errors == Report.Errors)
+ Report.Error (157, loc, "Control cannot leave the body of a finally clause");
} else {
- vector = vector.Clone ();
vector.Location = loc;
vector.Next = break_origins;
break_origins = vector;
public override bool AddContinueOrigin (UsageVector vector, Location loc)
{
+ vector = vector.Clone ();
if (finally_vector != null) {
- Report.Error (157, loc, "Control cannot leave the body of a finally clause");
+ vector.MergeChild (finally_vector, false);
+ int errors = Report.Errors;
+ Parent.AddContinueOrigin (vector, loc);
+ if (errors == Report.Errors)
+ Report.Error (157, loc, "Control cannot leave the body of a finally clause");
} else {
- vector = vector.Clone ();
vector.Location = loc;
vector.Next = continue_origins;
continue_origins = vector;
public override bool AddReturnOrigin (UsageVector vector, Location loc)
{
+ vector = vector.Clone ();
if (finally_vector != null) {
- Report.Error (157, loc, "Control cannot leave the body of a finally clause");
+ vector.MergeChild (finally_vector, false);
+ int errors = Report.Errors;
+ Parent.AddReturnOrigin (vector, loc);
+ if (errors == Report.Errors)
+ Report.Error (157, loc, "Control cannot leave the body of a finally clause");
} else {
- vector = vector.Clone ();
vector.Location = loc;
vector.Next = return_origins;
return_origins = vector;
return true;
}
+ public override bool AddGotoOrigin (UsageVector vector, Goto goto_stmt)
+ {
+ LabeledStatement s = current_vector.Block == null ? null : current_vector.Block.LookupLabel (goto_stmt.Target);
+ if (s != null)
+ throw new InternalErrorException ("Shouldn't get here");
+
+ vector = vector.Clone ();
+ if (finally_vector != null) {
+ vector.MergeChild (finally_vector, false);
+ int errors = Report.Errors;
+ Parent.AddGotoOrigin (vector, goto_stmt);
+ if (errors == Report.Errors)
+ Report.Error (157, goto_stmt.loc, "Control cannot leave the body of a finally clause");
+ } else {
+ goto_origins = new GotoOrigin (vector, goto_stmt, goto_origins);
+ }
+ return true;
+ }
+
public override void StealFinallyClauses (ref ArrayList list)
{
if (list == null)
get { return emit_finally; }
}
- public override LabeledStatement LookupLabel (string name, Location loc)
- {
- if (current_vector.Block == null)
- return base.LookupLabel (name, loc);
-
- LabeledStatement s = current_vector.Block.LookupLabel (name);
- if (s != null)
- return s;
-
- if (finally_vector != null) {
- Report.Error (157, loc,
- "Control cannot leave the body of a finally clause");
- return null;
- }
-
- return base.LookupLabel (name, loc);
- }
-
- public override void Label (UsageVector origin_vectors)
- {
- CurrentUsageVector.MergeJumpOrigins (origin_vectors);
- }
-
protected override UsageVector Merge ()
{
- UsageVector vector = Merge (catch_vectors);
+ Report.Debug (2, " MERGING TRY/CATCH", Name);
+ UsageVector vector = UsageVector.MergeSiblings (catch_vectors, Location);
+ Report.Debug (2, " MERGING TRY/CATCH DONE", vector);
if (finally_vector != null)
vector.MergeChild (finally_vector, false);
for (UsageVector origin = break_origins; origin != null; origin = origin.Next) {
if (finally_vector != null)
origin.MergeChild (finally_vector, false);
- if (!origin.Reachability.IsUnreachable)
- Parent.AddBreakOrigin (origin, origin.Location);
+ Parent.AddBreakOrigin (origin, origin.Location);
}
for (UsageVector origin = continue_origins; origin != null; origin = origin.Next) {
if (finally_vector != null)
origin.MergeChild (finally_vector, false);
- if (!origin.Reachability.IsUnreachable)
- Parent.AddContinueOrigin (origin, origin.Location);
+ Parent.AddContinueOrigin (origin, origin.Location);
}
for (UsageVector origin = return_origins; origin != null; origin = origin.Next) {
if (finally_vector != null)
origin.MergeChild (finally_vector, false);
- if (!origin.Reachability.IsUnreachable)
- Parent.AddReturnOrigin (origin, origin.Location);
+ Parent.AddReturnOrigin (origin, origin.Location);
+ }
+
+ for (GotoOrigin origin = goto_origins; origin != null; origin = origin.Next) {
+ if (finally_vector != null)
+ origin.Vector.MergeChild (finally_vector, false);
+ Parent.AddGotoOrigin (origin.Vector, origin.GotoStmt);
}
return vector;
ArrayList non_public_fields = new ArrayList ();
if (fields != null) {
- foreach (FieldMember field in fields) {
+ foreach (FieldBase field in fields) {
if ((field.ModFlags & Modifiers.STATIC) != 0)
continue;
if ((field.ModFlags & Modifiers.PUBLIC) != 0)
Fields = new FieldInfo [Count];
public_fields.CopyTo (Fields, 0);
non_public_fields.CopyTo (Fields, CountPublic);
+#if GMCS_SOURCE
+ } else if (type is GenericTypeParameterBuilder) {
+ CountPublic = CountNonPublic = Count = 0;
+
+ Fields = new FieldInfo [0];
+#endif
} else {
FieldInfo[] public_fields = type.GetFields (
BindingFlags.Instance|BindingFlags.Public);
// </summary>
public class MyBitVector {
public readonly int Count;
- public MyBitVector InheritsFrom;
public static readonly MyBitVector Empty = new MyBitVector ();
- BitArray vector;
+ // Invariant: vector != null => vector.Count == Count
+ // Invariant: vector == null || shared == null
+ // i.e., at most one of 'vector' and 'shared' can be non-null. They can both be null -- that means all-ones
+ // The object in 'shared' cannot be modified, while 'vector' can be freely modified
+ BitArray vector, shared;
MyBitVector ()
{
- InheritsFrom = null;
- Count = 0;
+ shared = new BitArray (0, false);
}
public MyBitVector (MyBitVector InheritsFrom, int Count)
{
- if (InheritsFrom != null) {
- while (InheritsFrom.InheritsFrom != null)
- InheritsFrom = InheritsFrom.InheritsFrom;
- if (InheritsFrom.Count >= Count && InheritsFrom.vector == null)
- InheritsFrom = null;
- }
+ if (InheritsFrom != null)
+ shared = InheritsFrom.Shared;
- this.InheritsFrom = InheritsFrom;
this.Count = Count;
}
+ // Use this accessor to get a shareable copy of the underlying BitArray representation
+ BitArray Shared {
+ get {
+ // Post-condition: vector == null
+ if (shared == null) {
+ shared = vector;
+ vector = null;
+ }
+ return shared;
+ }
+ }
+
// <summary>
// Get/set bit `index' in the bit vector.
// </summary>
- public bool this [int index]
- {
+ 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];
- if (InheritsFrom == null)
+ if (shared == null)
return true;
- if (index < InheritsFrom.Count)
- return InheritsFrom [index];
+ if (index < shared.Count)
+ return shared [index];
return false;
}
// Performs an `or' operation on the bit vector. The `new_vector' may have a
// different size than the current one.
// </summary>
- private void Or (MyBitVector new_vector)
+ private MyBitVector Or (MyBitVector new_vector)
{
- int min = new_vector.Count;
+ if (Count == 0 || new_vector.Count == 0)
+ return this;
+
+ BitArray o = new_vector.vector != null ? new_vector.vector : new_vector.shared;
+
+ if (o == null) {
+ int n = new_vector.Count;
+ if (n < Count) {
+ for (int i = 0; i < n; ++i)
+ this [i] = true;
+ } else {
+ SetAll (true);
+ }
+ return this;
+ }
+
+ if (Count == o.Count) {
+ if (vector == null) {
+ if (shared == null)
+ return this;
+ initialize_vector ();
+ }
+ vector.Or (o);
+ return this;
+ }
+
+ int min = o.Count;
if (Count < min)
min = Count;
- for (int i = 0; i < min; i++)
- this [i] |= new_vector [i];
+ for (int i = 0; i < min; i++) {
+ if (o [i])
+ this [i] = true;
+ }
+
+ return this;
}
// <summary>
- // Perfonrms an `and' operation on the bit vector. The `new_vector' may have
+ // Performs an `and' operation on the bit vector. The `new_vector' may have
// a different size than the current one.
// </summary>
- private void And (MyBitVector new_vector)
+ private MyBitVector And (MyBitVector new_vector)
{
- int min = new_vector.Count;
+ if (Count == 0)
+ return this;
+
+ BitArray o = new_vector.vector != null ? new_vector.vector : new_vector.shared;
+
+ if (o == null) {
+ for (int i = new_vector.Count; i < Count; ++i)
+ this [i] = false;
+ return this;
+ }
+
+ if (o.Count == 0) {
+ SetAll (false);
+ return this;
+ }
+
+ if (Count == o.Count) {
+ if (vector == null) {
+ if (shared == null) {
+ shared = new_vector.Shared;
+ return this;
+ }
+ initialize_vector ();
+ }
+ vector.And (o);
+ return this;
+ }
+
+ int min = o.Count;
if (Count < min)
min = Count;
- for (int i = 0; i < min; i++)
- this [i] &= new_vector [i];
+ for (int i = 0; i < min; i++) {
+ if (! o [i])
+ this [i] = false;
+ }
for (int i = min; i < Count; i++)
this [i] = false;
+
+ return this;
}
- public static void And (ref MyBitVector target, MyBitVector vector)
+ public static MyBitVector operator & (MyBitVector a, MyBitVector b)
{
- if (vector == null)
- return;
- if (target == null)
- target = vector.Clone ();
+ if (a == b)
+ return a;
+ if (a == null)
+ return b.Clone ();
+ if (b == null)
+ return a.Clone ();
+ if (a.Count > b.Count)
+ return a.Clone ().And (b);
else
- target.And (vector);
+ return b.Clone ().And (a);
}
- public static void Or (ref MyBitVector target, MyBitVector vector)
+ public static MyBitVector operator | (MyBitVector a, MyBitVector b)
{
- if (target == null)
- return;
- if (vector == null)
- target = null;
+ if (a == b)
+ return a;
+ if (a == null)
+ return new MyBitVector (null, b.Count);
+ if (b == null)
+ return new MyBitVector (null, a.Count);
+ if (a.Count > b.Count)
+ return a.Clone ().Or (b);
else
- target.Or (vector);
+ return b.Clone ().Or (a);
}
- // <summary>
- // This does a deep copy of the bit vector.
- // </summary>
public MyBitVector Clone ()
{
+ return Count == 0 ? Empty : new MyBitVector (this, Count);
+ }
+
+ public void SetAll (bool value)
+ {
+ // Don't clobber Empty
if (Count == 0)
- return Empty;
- MyBitVector retval = new MyBitVector (this, Count);
- retval.initialize_vector ();
- return retval;
+ return;
+ shared = value ? null : Empty.Shared;
+ vector = null;
}
void initialize_vector ()
{
- if (InheritsFrom == null) {
+ // Post-condition: vector != null
+ if (shared == null) {
vector = new BitArray (Count, true);
return;
}
- vector = new BitArray (Count, false);
-
- int min = InheritsFrom.Count;
- if (min > Count)
- min = Count;
-
- for (int i = 0; i < min; i++)
- vector [i] = InheritsFrom [i];
-
- InheritsFrom = null;
+ vector = new BitArray (shared);
+ if (Count != vector.Count)
+ vector.Length = Count;
+ shared = null;
}
StringBuilder Dump (StringBuilder sb)
{
- if (vector == null)
- return InheritsFrom == null ? sb.Append ("/") : InheritsFrom.Dump (sb.Append ("="));
- for (int i = 0; i < Count; i++)
- sb.Append (this [i] ? "1" : "0");
+ BitArray dump = vector == null ? shared : vector;
+ if (dump == null)
+ return sb.Append ("/");
+ if (dump == shared)
+ sb.Append ("=");
+ for (int i = 0; i < dump.Count; i++)
+ sb.Append (dump [i] ? "1" : "0");
return sb;
}
projects / mono.git / blobdiff