X-Git-Url: http://wien.tomnetworks.com/gitweb/?a=blobdiff_plain;f=mcs%2Fmcs%2Fflowanalysis.cs;h=c9f58f9fc1b1e3267e5bbe16be1056193bfeb053;hb=844983bf87468ee3fc786ce8a6f8c7aeedb1f09a;hp=528c0fb506e6f915f7002e7cc764b56ef92660c8;hpb=769a3cfe4be5f4217bd57785501af28073bd7b1c;p=mono.git
diff --git a/mcs/mcs/flowanalysis.cs b/mcs/mcs/flowanalysis.cs
index 528c0fb506e..c9f58f9fc1b 100644
--- a/mcs/mcs/flowanalysis.cs
+++ b/mcs/mcs/flowanalysis.cs
@@ -5,7 +5,8 @@
// Martin Baulig (martin@ximian.com)
// Raja R Harinath (rharinath@novell.com)
//
-// (C) 2001, 2002, 2003 Ximian, Inc.
+// Copyright 2001, 2002, 2003 Ximian, Inc.
+// Copyright 2003-2008 Novell, Inc.
//
using System;
@@ -17,13 +18,6 @@ using System.Diagnostics;
namespace Mono.CSharp
{
- public enum TriState : byte {
- // Never < Sometimes < Always
- Never,
- Sometimes,
- Always
- }
-
//
// 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.
@@ -49,17 +43,20 @@ namespace Mono.CSharp
// part of a block headed by a jump target
Labeled,
- // Try/Catch block.
+ // TryCatch block.
+ TryCatch,
+
+ // TryFinally, Using, Lock, CollectionForeach
Exception,
// Switch block.
Switch,
- // Switch section.
- SwitchSection,
-
// The toplevel block of a function
- Toplevel
+ Toplevel,
+
+ // An iterator block
+ Iterator
}
//
@@ -74,147 +71,18 @@ namespace Mono.CSharp
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) {
case BranchingType.Exception:
case BranchingType.Labeled:
case BranchingType.Toplevel:
+ case BranchingType.TryCatch:
throw new InvalidOperationException ();
case BranchingType.Switch:
return new FlowBranchingBreakable (parent, type, SiblingType.SwitchSection, block, loc);
- case BranchingType.SwitchSection:
- return new FlowBranchingBlock (parent, type, SiblingType.Block, block, loc);
-
case BranchingType.Block:
return new FlowBranchingBlock (parent, type, SiblingType.Block, block, loc);
@@ -250,8 +118,6 @@ namespace Mono.CSharp
//
public readonly Location Location;
- protected VariableMap param_map, local_map;
-
static int next_id = 0;
int id;
@@ -275,11 +141,6 @@ namespace Mono.CSharp
//
public readonly Block Block;
- //
- // The number of parameters in this block.
- //
- public readonly int CountParameters;
-
//
// The number of locals in this block.
//
@@ -300,8 +161,8 @@ namespace Mono.CSharp
//
// Private.
//
- MyBitVector locals, parameters;
- Reachability reachability;
+ MyBitVector locals;
+ bool is_unreachable;
static int next_id = 0;
int id;
@@ -309,43 +170,41 @@ namespace Mono.CSharp
//
// Normally, you should not use any of these constructors.
//
- public UsageVector (SiblingType type, UsageVector parent, Block block, Location loc, int num_params, int num_locals)
+ public UsageVector (SiblingType type, UsageVector parent, Block block, Location loc, int num_locals)
{
this.Type = type;
this.Block = block;
this.Location = loc;
this.InheritsFrom = parent;
- this.CountParameters = num_params;
this.CountLocals = num_locals;
locals = num_locals == 0
? MyBitVector.Empty
: new MyBitVector (parent == null ? MyBitVector.Empty : parent.locals, num_locals);
- parameters = num_params == 0
- ? 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)
+ : this (type, parent, block, loc, parent.CountLocals)
{ }
- public UsageVector (MyBitVector parameters, MyBitVector locals, Reachability reachability, Block block, Location loc)
+ private UsageVector (MyBitVector locals, bool is_unreachable, Block block, Location loc)
{
this.Type = SiblingType.Block;
this.Location = loc;
this.Block = block;
- this.reachability = reachability;
- this.parameters = parameters;
+ this.is_unreachable = is_unreachable;
+
this.locals = locals;
id = ++next_id;
+
}
//
@@ -353,69 +212,58 @@ namespace Mono.CSharp
//
public UsageVector Clone ()
{
- UsageVector retval = new UsageVector (Type, null, Block, Location, CountParameters, CountLocals);
+ UsageVector retval = new UsageVector (Type, null, Block, Location, CountLocals);
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);
+ return var.IsAssigned (locals);
}
public void SetAssigned (VariableInfo var)
{
- if (!var.IsParameter && Reachability.IsUnreachable)
+ if (!var.IsParameter && IsUnreachable)
return;
- var.SetAssigned (var.IsParameter ? parameters : locals);
+ var.SetAssigned (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);
+ return var.IsFieldAssigned (locals, name);
}
public void SetFieldAssigned (VariableInfo var, string name)
{
- if (!var.IsParameter && Reachability.IsUnreachable)
+ if (!var.IsParameter && IsUnreachable)
return;
- var.SetFieldAssigned (var.IsParameter ? parameters : locals, name);
- }
-
- public Reachability Reachability {
- get { return reachability; }
+ var.SetFieldAssigned (locals, name);
}
- public void Return ()
- {
- if (!reachability.IsUnreachable)
- reachability.SetReturns ();
+ public bool IsUnreachable {
+ get { return is_unreachable; }
}
- public void Throw ()
+ public void ResetBarrier ()
{
- if (!reachability.IsUnreachable) {
- reachability.SetThrows ();
- reachability.SetBarrier ();
- }
+ is_unreachable = false;
}
public void Goto ()
{
- if (!reachability.IsUnreachable)
- reachability.SetBarrier ();
+ is_unreachable = true;
}
public static UsageVector MergeSiblings (UsageVector sibling_list, Location loc)
@@ -424,72 +272,19 @@ namespace Mono.CSharp
return sibling_list;
MyBitVector locals = null;
- MyBitVector parameters = null;
- Reachability reachability = null;
-
- for (UsageVector child = sibling_list; child != null; child = child.Next) {
- Report.Debug (2, " MERGING SIBLING ", reachability, child);
+ bool is_unreachable = sibling_list.is_unreachable;
- 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;
+ if (!sibling_list.IsUnreachable)
+ locals &= sibling_list.locals;
- Report.Debug (2, " MERGING SIBLING #1", reachability,
- child.Type, child.Reachability.IsUnreachable, unreachable);
+ for (UsageVector child = sibling_list.Next; child != null; child = child.Next) {
+ is_unreachable &= child.is_unreachable;
- if (!unreachable)
+ if (!child.IsUnreachable)
locals &= child.locals;
-
- // An `out' parameter must be assigned in all branches which do
- // not always throw an exception.
- if (!child.Reachability.AlwaysThrows)
- parameters &= child.parameters;
-
- Report.Debug (2, " MERGING SIBLING #2", parameters, locals);
}
-
- if (reachability == null)
- throw new InternalErrorException ("Cannot happen: the loop above runs at least twice");
- return new UsageVector (parameters, locals, reachability, null, loc);
+ return new UsageVector (locals, is_unreachable, null, loc);
}
//
@@ -497,9 +292,9 @@ namespace Mono.CSharp
//
public UsageVector MergeChild (UsageVector child, bool overwrite)
{
- Report.Debug (2, " MERGING CHILD EFFECTS", this, child, 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
@@ -510,7 +305,7 @@ namespace Mono.CSharp
// 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");
@@ -518,12 +313,15 @@ namespace Mono.CSharp
}
locals |= child.locals;
- parameters |= child.parameters;
+
+ // throw away un-necessary information about variables in child blocks
+ if (locals.Count != CountLocals)
+ locals = new MyBitVector (locals, CountLocals);
if (overwrite)
- reachability = new_r.Clone ();
+ is_unreachable = new_isunr;
else
- reachability.Or (new_r);
+ is_unreachable |= new_isunr;
return child;
}
@@ -535,20 +333,15 @@ namespace Mono.CSharp
if (o_vectors == null)
return;
- if (reachability.IsUnreachable) {
- if (locals != null)
- locals.SetAll (true);
- if (parameters != null)
- parameters.SetAll (true);
- }
+ if (IsUnreachable && locals != null)
+ locals.SetAll (true);
for (UsageVector vector = o_vectors; vector != null; vector = vector.Next) {
Report.Debug (1, " MERGING BREAK ORIGIN", vector);
- if (vector.Reachability.IsUnreachable)
+ if (vector.IsUnreachable)
continue;
locals &= vector.locals;
- parameters &= vector.parameters;
- reachability.Meet (vector.Reachability);
+ is_unreachable &= vector.is_unreachable;
}
Report.Debug (1, " MERGING BREAK ORIGINS DONE", this);
@@ -560,7 +353,7 @@ namespace Mono.CSharp
public override string ToString ()
{
- return String.Format ("Vector ({0},{1},{2}-{3}-{4})", Type, id, reachability, parameters, locals);
+ return String.Format ("Vector ({0},{1},{2}-{3})", Type, id, is_unreachable, locals);
}
}
@@ -581,18 +374,10 @@ namespace Mono.CSharp
UsageVector vector;
if (Block != null) {
- param_map = Block.ParameterMap;
- local_map = Block.LocalMap;
-
UsageVector parent_vector = parent != null ? parent.CurrentUsageVector : null;
- vector = new UsageVector (
- stype, parent_vector, Block, loc,
- param_map.Length, local_map.Length);
+ vector = new UsageVector (stype, parent_vector, Block, loc, Block.AssignableSlots);
} else {
- param_map = Parent.param_map;
- local_map = Parent.local_map;
- vector = new UsageVector (
- stype, Parent.CurrentUsageVector, null, loc);
+ vector = new UsageVector (stype, Parent.CurrentUsageVector, null, loc);
}
AddSibling (vector);
@@ -623,22 +408,19 @@ namespace Mono.CSharp
protected abstract UsageVector Merge ();
- //
- // Merge a child branching.
- //
public UsageVector MergeChild (FlowBranching child)
{
- 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 (), overwrite);
- Report.Debug (2, " MERGING CHILD DONE", this, result);
- return result;
+ return CurrentUsageVector.MergeChild (child.Merge (), true);
}
- public virtual bool InTryWithCatch ()
+ public virtual bool CheckRethrow (Location loc)
{
- return Parent.InTryWithCatch ();
+ return Parent.CheckRethrow (loc);
+ }
+
+ public virtual bool AddResumePoint (ResumableStatement stmt, Location loc, out int pc)
+ {
+ return Parent.AddResumePoint (stmt, loc, out pc);
}
// returns true if we crossed an unwind-protected region (try/catch/finally, lock, using, ...)
@@ -654,9 +436,9 @@ namespace Mono.CSharp
}
// returns true if we crossed an unwind-protected region (try/catch/finally, lock, using, ...)
- public virtual bool AddReturnOrigin (UsageVector vector, Location loc)
+ public virtual bool AddReturnOrigin (UsageVector vector, ExitStatement stmt)
{
- return Parent.AddReturnOrigin (vector, loc);
+ return Parent.AddReturnOrigin (vector, stmt);
}
// returns true if we crossed an unwind-protected region (try/catch/finally, lock, using, ...)
@@ -665,11 +447,6 @@ namespace Mono.CSharp
return Parent.AddGotoOrigin (vector, goto_stmt);
}
- public virtual void StealFinallyClauses (ref ArrayList list)
- {
- Parent.StealFinallyClauses (ref list);
- }
-
public bool IsAssigned (VariableInfo vi)
{
return CurrentUsageVector.IsAssigned (vi, false);
@@ -680,6 +457,10 @@ namespace Mono.CSharp
return CurrentUsageVector.IsAssigned (vi, false) || CurrentUsageVector.IsFieldAssigned (vi, field_name);
}
+ protected static Report Report {
+ get { return RootContext.ToplevelTypes.Compiler.Report; }
+ }
+
public void SetAssigned (VariableInfo vi)
{
CurrentUsageVector.SetAssigned (vi);
@@ -733,6 +514,8 @@ namespace Mono.CSharp
protected override void AddSibling (UsageVector sibling)
{
+ if (sibling_list != null && sibling_list.Type == SiblingType.Block)
+ throw new InternalErrorException ("Blocks don't have sibling flow paths");
sibling.Next = sibling_list;
sibling_list = sibling;
}
@@ -748,6 +531,12 @@ namespace Mono.CSharp
stmt.AddUsageVector (vector);
return false;
}
+
+ public static void Error_UnknownLabel (Location loc, string label, Report Report)
+ {
+ Report.Error(159, loc, "The label `{0}:' could not be found within the scope of the goto statement",
+ label);
+ }
protected override UsageVector Merge ()
{
@@ -819,7 +608,7 @@ namespace Mono.CSharp
actual = CurrentUsageVector.Clone ();
// stand-in for backward jumps
- CurrentUsageVector.Reachability.Meet (Reachability.Always ());
+ CurrentUsageVector.ResetBarrier ();
}
public override bool AddGotoOrigin (UsageVector vector, Goto goto_stmt)
@@ -838,7 +627,7 @@ namespace Mono.CSharp
{
UsageVector vector = base.Merge ();
- if (actual.Reachability.IsUnreachable)
+ if (actual.IsUnreachable)
Report.Warning (162, 2, stmt.loc, "Unreachable code detected");
actual.MergeChild (vector, false);
@@ -846,6 +635,22 @@ namespace Mono.CSharp
}
}
+ public class FlowBranchingIterator : FlowBranchingBlock
+ {
+ Iterator iterator;
+ public FlowBranchingIterator (FlowBranching parent, Iterator iterator)
+ : base (parent, BranchingType.Iterator, SiblingType.Block, null, iterator.Location)
+ {
+ this.iterator = iterator;
+ }
+
+ public override bool AddResumePoint (ResumableStatement stmt, Location loc, out int pc)
+ {
+ pc = iterator.AddResumePoint (stmt);
+ return false;
+ }
+ }
+
public class FlowBranchingToplevel : FlowBranchingBlock
{
UsageVector return_origins;
@@ -855,30 +660,15 @@ namespace Mono.CSharp
{
}
- //
- // Check whether all `out' parameters have been assigned.
- //
- void CheckOutParameters (UsageVector vector, Location loc)
+ public override bool CheckRethrow (Location loc)
{
- if (vector.Reachability.IsUnreachable)
- return;
- for (int i = 0; i < param_map.Count; i++) {
- VariableInfo var = param_map [i];
-
- if (var == null)
- continue;
-
- if (vector.IsAssigned (var, false))
- continue;
-
- Report.Error (177, loc, "The out parameter `{0}' must be assigned to before control leaves the current method",
- var.Name);
- }
+ Report.Error (156, loc, "A throw statement with no arguments is not allowed outside of a catch clause");
+ return false;
}
- public override bool InTryWithCatch ()
+ public override bool AddResumePoint (ResumableStatement stmt, Location loc, out int pc)
{
- return false;
+ throw new InternalErrorException ("A yield in a non-iterator block");
}
public override bool AddBreakOrigin (UsageVector vector, Location loc)
@@ -893,20 +683,15 @@ namespace Mono.CSharp
return false;
}
- public override bool AddReturnOrigin (UsageVector vector, Location loc)
+ public override bool AddReturnOrigin (UsageVector vector, ExitStatement stmt)
{
vector = vector.Clone ();
- vector.Location = loc;
+ vector.Location = stmt.loc;
vector.Next = return_origins;
return_origins = vector;
return false;
}
- public override void StealFinallyClauses (ref ArrayList list)
- {
- // nothing to do
- }
-
public override bool AddGotoOrigin (UsageVector vector, Goto goto_stmt)
{
string name = goto_stmt.Target;
@@ -915,7 +700,7 @@ namespace Mono.CSharp
throw new InternalErrorException ("Shouldn't get here");
if (Parent == null) {
- Report.Error (159, goto_stmt.loc, "No such label `{0}' in this scope", name);
+ Error_UnknownLabel (goto_stmt.loc, name, Report);
return false;
}
@@ -929,17 +714,72 @@ namespace Mono.CSharp
protected override UsageVector Merge ()
{
for (UsageVector origin = return_origins; origin != null; origin = origin.Next)
- CheckOutParameters (origin, origin.Location);
+ Block.Toplevel.CheckOutParameters (origin, origin.Location);
UsageVector vector = base.Merge ();
- CheckOutParameters (vector, Block.loc);
+ Block.Toplevel.CheckOutParameters (vector, Block.loc);
// Note: we _do_not_ merge in the return origins
return vector;
}
- public Reachability End ()
+ public bool End ()
{
- return Merge ().Reachability;
+ return Merge ().IsUnreachable;
+ }
+ }
+
+ public class FlowBranchingTryCatch : FlowBranchingBlock
+ {
+ TryCatch stmt;
+ public FlowBranchingTryCatch (FlowBranching parent, TryCatch stmt)
+ : base (parent, BranchingType.Block, SiblingType.Try, null, stmt.loc)
+ {
+ this.stmt = stmt;
+ }
+
+ public override bool CheckRethrow (Location loc)
+ {
+ return CurrentUsageVector.Next != null || Parent.CheckRethrow (loc);
+ }
+
+ public override bool AddResumePoint (ResumableStatement stmt, Location loc, out int pc)
+ {
+ int errors = Report.Errors;
+ Parent.AddResumePoint (stmt, loc, out pc);
+ if (errors == Report.Errors) {
+ if (CurrentUsageVector.Next == null)
+ Report.Error (1626, loc, "Cannot yield a value in the body of a try block with a catch clause");
+ else
+ Report.Error (1631, loc, "Cannot yield a value in the body of a catch clause");
+ }
+ return true;
+ }
+
+ public override bool AddBreakOrigin (UsageVector vector, Location loc)
+ {
+ Parent.AddBreakOrigin (vector, loc);
+ stmt.SomeCodeFollows ();
+ return true;
+ }
+
+ public override bool AddContinueOrigin (UsageVector vector, Location loc)
+ {
+ Parent.AddContinueOrigin (vector, loc);
+ stmt.SomeCodeFollows ();
+ return true;
+ }
+
+ public override bool AddReturnOrigin (UsageVector vector, ExitStatement exit_stmt)
+ {
+ Parent.AddReturnOrigin (vector, exit_stmt);
+ stmt.SomeCodeFollows ();
+ return true;
+ }
+
+ public override bool AddGotoOrigin (UsageVector vector, Goto goto_stmt)
+ {
+ Parent.AddGotoOrigin (vector, goto_stmt);
+ return true;
}
}
@@ -947,28 +787,87 @@ namespace Mono.CSharp
{
ExceptionStatement stmt;
UsageVector current_vector;
- UsageVector catch_vectors;
+ UsageVector try_vector;
UsageVector finally_vector;
- UsageVector break_origins;
- UsageVector continue_origins;
- UsageVector return_origins;
- GotoOrigin goto_origins;
-
- class GotoOrigin {
- public GotoOrigin Next;
- public Goto GotoStmt;
- public UsageVector Vector;
+ abstract class SavedOrigin {
+ public readonly SavedOrigin Next;
+ public readonly UsageVector Vector;
- public GotoOrigin (UsageVector vector, Goto goto_stmt, GotoOrigin next)
+ protected SavedOrigin (SavedOrigin next, UsageVector vector)
{
- Vector = vector;
- GotoStmt = goto_stmt;
Next = next;
+ Vector = vector.Clone ();
+ }
+
+ protected abstract void DoPropagateFinally (FlowBranching parent);
+ public void PropagateFinally (UsageVector finally_vector, FlowBranching parent)
+ {
+ if (finally_vector != null)
+ Vector.MergeChild (finally_vector, false);
+ DoPropagateFinally (parent);
}
}
- bool emit_finally;
+ class BreakOrigin : SavedOrigin {
+ Location Loc;
+ public BreakOrigin (SavedOrigin next, UsageVector vector, Location loc)
+ : base (next, vector)
+ {
+ Loc = loc;
+ }
+
+ protected override void DoPropagateFinally (FlowBranching parent)
+ {
+ parent.AddBreakOrigin (Vector, Loc);
+ }
+ }
+
+ class ContinueOrigin : SavedOrigin {
+ Location Loc;
+ public ContinueOrigin (SavedOrigin next, UsageVector vector, Location loc)
+ : base (next, vector)
+ {
+ Loc = loc;
+ }
+
+ protected override void DoPropagateFinally (FlowBranching parent)
+ {
+ parent.AddContinueOrigin (Vector, Loc);
+ }
+ }
+
+ class ReturnOrigin : SavedOrigin {
+ public ExitStatement Stmt;
+
+ public ReturnOrigin (SavedOrigin next, UsageVector vector, ExitStatement stmt)
+ : base (next, vector)
+ {
+ Stmt = stmt;
+ }
+
+ protected override void DoPropagateFinally (FlowBranching parent)
+ {
+ parent.AddReturnOrigin (Vector, Stmt);
+ }
+ }
+
+ class GotoOrigin : SavedOrigin {
+ public Goto Stmt;
+
+ public GotoOrigin (SavedOrigin next, UsageVector vector, Goto stmt)
+ : base (next, vector)
+ {
+ Stmt = stmt;
+ }
+
+ protected override void DoPropagateFinally (FlowBranching parent)
+ {
+ parent.AddGotoOrigin (Vector, Stmt);
+ }
+ }
+
+ SavedOrigin saved_origins;
public FlowBranchingException (FlowBranching parent,
ExceptionStatement stmt)
@@ -976,16 +875,13 @@ namespace Mono.CSharp
null, stmt.loc)
{
this.stmt = stmt;
- this.emit_finally = true;
}
protected override void AddSibling (UsageVector sibling)
{
switch (sibling.Type) {
case SiblingType.Try:
- case SiblingType.Catch:
- sibling.Next = catch_vectors;
- catch_vectors = sibling;
+ try_vector = sibling;
break;
case SiblingType.Finally:
finally_vector = sibling;
@@ -1000,65 +896,74 @@ namespace Mono.CSharp
get { return current_vector; }
}
- public override bool InTryWithCatch ()
+ public override bool CheckRethrow (Location loc)
{
- if (finally_vector == null) {
- Try t = stmt as Try;
- if (t != null && t.HasCatch)
- return true;
- }
+ if (!Parent.CheckRethrow (loc))
+ return false;
+ if (finally_vector == null)
+ return true;
+ Report.Error (724, loc, "A throw statement with no arguments is not allowed inside of a finally clause nested inside of the innermost catch clause");
+ return false;
+ }
- return base.InTryWithCatch ();
+ public override bool AddResumePoint (ResumableStatement stmt, Location loc, out int pc)
+ {
+ int errors = Report.Errors;
+ Parent.AddResumePoint (this.stmt, loc, out pc);
+ if (errors == Report.Errors) {
+ if (finally_vector == null)
+ this.stmt.AddResumePoint (stmt, pc);
+ else
+ Report.Error (1625, loc, "Cannot yield in the body of a finally clause");
+ }
+ return true;
}
public override bool AddBreakOrigin (UsageVector vector, Location loc)
{
- vector = vector.Clone ();
if (finally_vector != null) {
- 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.Location = loc;
- vector.Next = break_origins;
- break_origins = vector;
+ saved_origins = new BreakOrigin (saved_origins, vector, loc);
}
+
+ // either the loop test or a back jump will follow code
+ stmt.SomeCodeFollows ();
return true;
}
public override bool AddContinueOrigin (UsageVector vector, Location loc)
{
- vector = vector.Clone ();
if (finally_vector != null) {
- 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.Location = loc;
- vector.Next = continue_origins;
- continue_origins = vector;
+ saved_origins = new ContinueOrigin (saved_origins, vector, loc);
}
+
+ // either the loop test or a back jump will follow code
+ stmt.SomeCodeFollows ();
return true;
}
- public override bool AddReturnOrigin (UsageVector vector, Location loc)
+ public override bool AddReturnOrigin (UsageVector vector, ExitStatement exit_stmt)
{
- vector = vector.Clone ();
if (finally_vector != null) {
- vector.MergeChild (finally_vector, false);
int errors = Report.Errors;
- Parent.AddReturnOrigin (vector, loc);
+ Parent.AddReturnOrigin (vector, exit_stmt);
if (errors == Report.Errors)
- Report.Error (157, loc, "Control cannot leave the body of a finally clause");
+ exit_stmt.Error_FinallyClause (Report);
} else {
- vector.Location = loc;
- vector.Next = return_origins;
- return_origins = vector;
+ saved_origins = new ReturnOrigin (saved_origins, vector, exit_stmt);
}
+
+ // sets ec.NeedReturnLabel()
+ stmt.SomeCodeFollows ();
return true;
}
@@ -1068,64 +973,26 @@ namespace Mono.CSharp
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);
+ saved_origins = new GotoOrigin (saved_origins, vector, goto_stmt);
}
return true;
}
- public override void StealFinallyClauses (ref ArrayList list)
- {
- if (list == null)
- list = new ArrayList ();
- list.Add (stmt);
- emit_finally = false;
- base.StealFinallyClauses (ref list);
- }
-
- public bool EmitFinally {
- get { return emit_finally; }
- }
-
protected override UsageVector Merge ()
{
- Report.Debug (2, " MERGING TRY/CATCH", Name);
- UsageVector vector = UsageVector.MergeSiblings (catch_vectors, Location);
- Report.Debug (2, " MERGING TRY/CATCH DONE", vector);
+ UsageVector vector = try_vector.Clone ();
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);
- Parent.AddBreakOrigin (origin, origin.Location);
- }
-
- for (UsageVector origin = continue_origins; origin != null; origin = origin.Next) {
- if (finally_vector != null)
- origin.MergeChild (finally_vector, false);
- Parent.AddContinueOrigin (origin, origin.Location);
- }
-
- for (UsageVector origin = return_origins; origin != null; origin = origin.Next) {
- if (finally_vector != null)
- origin.MergeChild (finally_vector, false);
- 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);
- }
+ for (SavedOrigin origin = saved_origins; origin != null; origin = origin.Next)
+ origin.PropagateFinally (finally_vector, Parent);
return vector;
}
@@ -1175,8 +1042,19 @@ namespace Mono.CSharp
//
public TypeInfo[] SubStructInfo;
- protected readonly StructInfo struct_info;
- private static Hashtable type_hash = new Hashtable ();
+ readonly StructInfo struct_info;
+ private static Hashtable type_hash;
+
+ static TypeInfo ()
+ {
+ Reset ();
+ }
+
+ public static void Reset ()
+ {
+ type_hash = new Hashtable ();
+ StructInfo.field_type_hash = new Hashtable ();
+ }
public static TypeInfo GetTypeInfo (Type type)
{
@@ -1234,7 +1112,7 @@ namespace Mono.CSharp
}
}
- protected TypeInfo (StructInfo struct_info, int offset)
+ TypeInfo (StructInfo struct_info, int offset)
{
this.struct_info = struct_info;
this.Offset = offset;
@@ -1265,19 +1143,27 @@ namespace Mono.CSharp
// A struct's constructor must always assign all fields.
// This method checks whether it actually does so.
//
- public bool IsFullyInitialized (FlowBranching branching, VariableInfo vi, Location loc)
+ public bool IsFullyInitialized (BlockContext ec, VariableInfo vi, Location loc)
{
if (struct_info == null)
return true;
bool ok = true;
+ FlowBranching branching = ec.CurrentBranching;
for (int i = 0; i < struct_info.Count; i++) {
FieldInfo field = struct_info.Fields [i];
if (!branching.IsFieldAssigned (vi, field.Name)) {
- Report.Error (171, loc,
- "Field `{0}' must be fully assigned before control leaves the constructor",
- TypeManager.GetFullNameSignature (field));
+ FieldBase fb = TypeManager.GetField (field);
+ if (fb is Property.BackingField) {
+ ec.Report.Error (843, loc,
+ "An automatically implemented property `{0}' must be fully assigned before control leaves the constructor. Consider calling default contructor",
+ fb.GetSignatureForError ());
+ } else {
+ ec.Report.Error (171, loc,
+ "Field `{0}' must be fully assigned before control leaves the constructor",
+ TypeManager.GetFullNameSignature (field));
+ }
ok = false;
}
}
@@ -1291,7 +1177,7 @@ namespace Mono.CSharp
Type, Offset, Length, TotalLength);
}
- protected class StructInfo {
+ class StructInfo {
public readonly Type Type;
public readonly FieldInfo[] Fields;
public readonly TypeInfo[] StructFields;
@@ -1302,7 +1188,7 @@ namespace Mono.CSharp
public readonly int TotalLength;
public readonly bool HasStructFields;
- private static Hashtable field_type_hash = new Hashtable ();
+ public static Hashtable field_type_hash;
private Hashtable struct_field_hash;
private Hashtable field_hash;
@@ -1316,18 +1202,20 @@ namespace Mono.CSharp
field_type_hash.Add (type, this);
- if (type is TypeBuilder) {
- TypeContainer tc = TypeManager.LookupTypeContainer (type);
-
- ArrayList fields = null;
- if (tc != null)
- fields = tc.Fields;
+ if (TypeManager.IsBeingCompiled (type)) {
+ TypeContainer tc = TypeManager.LookupTypeContainer (TypeManager.DropGenericTypeArguments (type));
ArrayList public_fields = new ArrayList ();
ArrayList non_public_fields = new ArrayList ();
+ //
+ // TODO: tc != null is needed because FixedBuffers are not cached
+ //
+ if (tc != null) {
+ ArrayList fields = tc.Fields;
+
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)
@@ -1336,6 +1224,7 @@ namespace Mono.CSharp
non_public_fields.Add (field.FieldBuilder);
}
}
+ }
CountPublic = public_fields.Count;
CountNonPublic = non_public_fields.Count;
@@ -1379,7 +1268,7 @@ namespace Mono.CSharp
if (sinfo [i] == null)
field_hash.Add (field.Name, ++Length);
else if (sinfo [i].InTransit) {
- Report.Error (523, String.Format (
+ RootContext.ToplevelTypes.Compiler.Report.Error (523, String.Format (
"Struct member `{0}.{1}' of type `{2}' causes " +
"a cycle in the structure layout",
type, field.Name, sinfo [i].Type));
@@ -1426,6 +1315,9 @@ namespace Mono.CSharp
TypeManager.IsBuiltinType (type))
return null;
+ if (TypeManager.IsGenericParameter (type))
+ return null;
+
StructInfo info = (StructInfo) field_type_hash [type];
if (info != null)
return info;
@@ -1472,11 +1364,15 @@ namespace Mono.CSharp
public readonly bool IsParameter;
public readonly LocalInfo LocalInfo;
- public readonly int ParameterIndex;
readonly VariableInfo Parent;
VariableInfo[] sub_info;
+ bool is_ever_assigned;
+ public bool IsEverAssigned {
+ get { return is_ever_assigned; }
+ }
+
protected VariableInfo (string name, Type type, int offset)
{
this.Name = name;
@@ -1498,7 +1394,6 @@ namespace Mono.CSharp
this.IsParameter = parent.IsParameter;
this.LocalInfo = parent.LocalInfo;
- this.ParameterIndex = parent.ParameterIndex;
Initialize ();
}
@@ -1523,26 +1418,25 @@ namespace Mono.CSharp
this.IsParameter = false;
}
- public VariableInfo (string name, Type type, int param_idx, int offset)
- : this (name, type, offset)
+ public VariableInfo (ParametersCompiled ip, int i, int offset)
+ : this (ip.FixedParameters [i].Name, ip.Types [i], offset)
{
- this.ParameterIndex = param_idx;
this.IsParameter = true;
}
- public bool IsAssigned (EmitContext ec)
+ public bool IsAssigned (ResolveContext ec)
{
return !ec.DoFlowAnalysis ||
ec.OmitStructFlowAnalysis && TypeInfo.IsStruct ||
ec.CurrentBranching.IsAssigned (this);
}
- public bool IsAssigned (EmitContext ec, Location loc)
+ public bool IsAssigned (ResolveContext ec, Location loc)
{
if (IsAssigned (ec))
return true;
- Report.Error (165, loc,
+ ec.Report.Error (165, loc,
"Use of unassigned local variable `" + Name + "'");
ec.CurrentBranching.SetAssigned (this);
return false;
@@ -1556,9 +1450,14 @@ namespace Mono.CSharp
if (vector [Offset])
return true;
- for (VariableInfo parent = Parent; parent != null; parent = parent.Parent)
- if (vector [parent.Offset])
+ // FIXME: Fix SetFieldAssigned to set the whole range like SetAssigned below. Then, get rid of this stanza
+ for (VariableInfo parent = Parent; parent != null; parent = parent.Parent) {
+ if (vector [parent.Offset]) {
+ // 'parent' is assigned, but someone forgot to note that all its components are assigned too
+ parent.SetAssigned (vector);
return true;
+ }
+ }
// Return unless this is a struct.
if (!TypeInfo.IsStruct)
@@ -1581,10 +1480,11 @@ namespace Mono.CSharp
}
vector [Offset] = true;
+ is_ever_assigned = true;
return true;
}
- public void SetAssigned (EmitContext ec)
+ public void SetAssigned (ResolveContext ec)
{
if (ec.DoFlowAnalysis)
ec.CurrentBranching.SetAssigned (this);
@@ -1592,17 +1492,21 @@ namespace Mono.CSharp
public void SetAssigned (MyBitVector vector)
{
- vector [Offset] = true;
+ if (Length == 1)
+ vector [Offset] = true;
+ else
+ vector.SetRange (Offset, Length);
+ is_ever_assigned = true;
}
- public bool IsFieldAssigned (EmitContext ec, string name, Location loc)
+ public bool IsFieldAssigned (ResolveContext ec, string name, Location loc)
{
if (!ec.DoFlowAnalysis ||
ec.OmitStructFlowAnalysis && TypeInfo.IsStruct ||
ec.CurrentBranching.IsFieldAssigned (this, name))
return true;
- Report.Error (170, loc,
+ ec.Report.Error (170, loc,
"Use of possibly unassigned field `" + name + "'");
ec.CurrentBranching.SetFieldAssigned (this, name);
return false;
@@ -1618,7 +1522,7 @@ namespace Mono.CSharp
return vector [Offset + field_idx];
}
- public void SetFieldAssigned (EmitContext ec, string name)
+ public void SetFieldAssigned (ResolveContext ec, string name)
{
if (ec.DoFlowAnalysis)
ec.CurrentBranching.SetFieldAssigned (this, name);
@@ -1632,6 +1536,7 @@ namespace Mono.CSharp
return;
vector [Offset + field_idx] = true;
+ is_ever_assigned = true;
}
public VariableInfo GetSubStruct (string name)
@@ -1651,105 +1556,6 @@ namespace Mono.CSharp
}
}
- //
- // This is used by the flow code to hold the `layout' of the flow vector for
- // all locals and all parameters (ie. we create one instance of this class for the
- // locals and another one for the params).
- //
- public class VariableMap {
- //
- // The number of variables in the map.
- //
- public readonly int Count;
-
- //
- // Total length of the flow vector for this map.
- //
- public readonly int Length;
-
- VariableInfo[] map;
-
- public VariableMap (Parameters ip)
- {
- Count = ip != null ? ip.Count : 0;
-
- // Dont bother allocating anything!
- if (Count == 0)
- return;
-
- Length = 0;
-
- for (int i = 0; i < Count; i++) {
- Parameter.Modifier mod = ip.ParameterModifier (i);
-
- if ((mod & Parameter.Modifier.OUT) != Parameter.Modifier.OUT)
- continue;
-
- // Dont allocate till we find an out var.
- if (map == null)
- map = new VariableInfo [Count];
-
- map [i] = new VariableInfo (ip.ParameterName (i),
- TypeManager.GetElementType (ip.ParameterType (i)), i, Length);
-
- Length += map [i].Length;
- }
- }
-
- public VariableMap (LocalInfo[] locals)
- : this (null, locals)
- { }
-
- public VariableMap (VariableMap parent, LocalInfo[] locals)
- {
- int offset = 0, start = 0;
- if (parent != null && parent.map != null) {
- offset = parent.Length;
- start = parent.Count;
- }
-
- Count = locals.Length + start;
-
- if (Count == 0)
- return;
-
- map = new VariableInfo [Count];
- Length = offset;
-
- if (parent != null && parent.map != null) {
- parent.map.CopyTo (map, 0);
- }
-
- for (int i = start; i < Count; i++) {
- LocalInfo li = locals [i-start];
-
- if (li.VariableType == null)
- continue;
-
- map [i] = li.VariableInfo = new VariableInfo (li, Length);
- Length += map [i].Length;
- }
- }
-
- //
- // Returns the VariableInfo for variable @index or null if we don't need to
- // compute assignment info for this variable.
- //
- public VariableInfo this [int index] {
- get {
- if (map == null)
- return null;
-
- return map [index];
- }
- }
-
- public override string ToString ()
- {
- return String.Format ("VariableMap ({0}:{1})", Count, Length);
- }
- }
-
//
// 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
@@ -1759,30 +1565,41 @@ namespace Mono.CSharp
public readonly int Count;
public static readonly MyBitVector Empty = new MyBitVector ();
+ // 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 ()
{
- vector = null;
shared = new BitArray (0, false);
- Count = 0;
}
public MyBitVector (MyBitVector InheritsFrom, int Count)
{
- vector = null;
- shared = InheritsFrom == null ? null : InheritsFrom.Shared;
+ if (InheritsFrom != null)
+ shared = InheritsFrom.MakeShared (Count);
+
this.Count = Count;
}
- BitArray Shared {
- get {
- if (shared == null) {
- shared = vector;
- vector = null;
- }
- return shared;
+ BitArray MakeShared (int new_count)
+ {
+ // Post-condition: vector == null
+
+ // ensure we don't leak out dirty bits from the BitVector we inherited from
+ if (new_count > Count &&
+ ((shared != null && shared.Count > Count) ||
+ (shared == null && vector == null)))
+ initialize_vector ();
+
+ if (vector != null) {
+ shared = vector;
+ vector = null;
}
+
+ return shared;
}
//
@@ -1791,7 +1608,9 @@ namespace Mono.CSharp
public bool this [int index] {
get {
if (index >= Count)
- throw new ArgumentOutOfRangeException ();
+ // FIXME: Disabled due to missing anonymous method flow analysis
+ // throw new ArgumentOutOfRangeException ();
+ return true;
if (vector != null)
return vector [index];
@@ -1818,28 +1637,86 @@ namespace Mono.CSharp
//
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;
}
//
- // 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.
//
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.MakeShared (Count);
+ 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;
@@ -1849,8 +1726,8 @@ namespace Mono.CSharp
public static MyBitVector operator & (MyBitVector a, MyBitVector b)
{
- if (a == null && b == null)
- return null;
+ if (a == b)
+ return a;
if (a == null)
return b.Clone ();
if (b == null)
@@ -1863,8 +1740,8 @@ namespace Mono.CSharp
public static MyBitVector operator | (MyBitVector a, MyBitVector b)
{
- if (a == null && b == null)
- return null;
+ if (a == b)
+ return a;
if (a == null)
return new MyBitVector (null, b.Count);
if (b == null)
@@ -1880,31 +1757,50 @@ namespace Mono.CSharp
return Count == 0 ? Empty : new MyBitVector (this, Count);
}
+ public void SetRange (int offset, int length)
+ {
+ if (offset > Count || offset + length > Count)
+ throw new ArgumentOutOfRangeException ();
+
+ if (shared == null && vector == null)
+ return;
+
+ int i = 0;
+ if (shared != null) {
+ if (offset + length <= shared.Count) {
+ for (; i < length; ++i)
+ if (!shared [i+offset])
+ break;
+ if (i == length)
+ return;
+ }
+ initialize_vector ();
+ }
+ for (; i < length; ++i)
+ vector [i+offset] = true;
+
+ }
+
public void SetAll (bool value)
{
// Don't clobber Empty
if (Count == 0)
return;
- shared = value ? null : Empty.Shared;
+ shared = value ? null : Empty.MakeShared (Count);
vector = null;
}
void initialize_vector ()
{
+ // Post-condition: vector != null
if (shared == null) {
vector = new BitArray (Count, true);
return;
}
- vector = new BitArray (Count, false);
-
- int min = shared.Count;
- if (min > Count)
- min = Count;
-
- for (int i = 0; i < min; i++)
- vector [i] = shared [i];
-
+ vector = new BitArray (shared);
+ if (Count != vector.Count)
+ vector.Length = Count;
shared = null;
}